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Title:
Masks, Maidens and Men: Gender and Interpretations of the Cult of Artemis Orthia at Sparta
Description:
This interdisciplinary and intersectional thesis addresses the cult of Artemis Orthia at Sparta and particularly the 6th century BCE grotesque terracotta masks recovered there by the British School of Athens in the early 20th century. Using both material culture and literary data as primary sources, this thesis seeks to re-evaluate interpretations of the site and these objects through a deconstructive, post processual approach with a particularly gender based focus. Explicit archaeological findings and implicit references to the site in literature are first detailed in an overview of the accessible classical material. Grounding the objects and the site in both an ancient Greek context and a wider understanding of classical reception of Greece, Greek religion, drama, art, and the Spartan mirage in Western thought, this thesis then seeks to discuss both Artemis and Orthia as separate and assimilated. Perpetuated accounts of the site as solely concerned with the flagellation of young men, marriage, and coming of age ceremonies are opened to new questions regarding origins and purposes of the cult, participation by people with a diversity in age, gender, and social classes, and new questions regarding marginalized perspectives in both classical material and the classical tradition of scholarship. This thesis concludes with an argument against repeated assumptions about the purpose of the objects, the site, the participants, the nature of the goddesses, and Spartan exceptionalism; questions once thought to have been answered are once again drawn to the forefront of the discussion.
Author/Creators:
Suddaby, Toryn A.
Title:
Improving ethanol productivity through self-cycling fermentation of yeast: a proof of concept
Description:
Background The cellulosic ethanol industry has developed efficient strategies for converting sugars obtained from various cellulosic feedstocks to bioethanol. However, any further major improvements in ethanol productivity will require development of novel and innovative fermentation strategies that enhance incumbent technologies in a cost-effective manner. The present study investigates the feasibility of applying self-cycling fermentation (SCF) to cellulosic ethanol production to elevate productivity. SCF is a semi-continuous cycling process that employs the following strategy: once the onset of stationary phase is detected, half of the broth volume is automatically harvested and replaced with fresh medium to initiate the next cycle. SCF has been shown to increase product yield and/or productivity in many types of microbial cultivation. To test whether this cycling process could increase productivity during ethanol fermentations, we mimicked the process by manually cycling the fermentation for five cycles in shake flasks, and then compared the results to batch operation. Results Mimicking SCF for five cycles resulted in regular patterns with regards to glucose consumption, ethanol titer, pH, and biomass production. Compared to batch fermentation, our cycling strategy displayed improved ethanol volumetric productivity (the titer of ethanol produced in a given cycle per corresponding cycle time) and specific productivity (the amount of ethanol produced per cellular biomass) by 43.1 ± 11.6 and 42.7 ± 9.8%, respectively. Five successive cycles contributed to an improvement of overall productivity (the aggregate amount of ethanol produced at the end of a given cycle per total processing time) and the estimated annual ethanol productivity (the amount of ethanol produced per year) by 64.4 ± 3.3 and 33.1 ± 7.2%, respectively. Conclusions This study provides proof of concept that applying SCF to ethanol production could significantly increase productivities, which will help strengthen the cellulosic ethanol industry.
Author/Creators:
Wang, Jie
Title:
Giving a Kahoot about Assessment in the Classroom
Description:
As library sessions are typically one-shot sessions with limited time, it is difficult to gauge students’ comprehension of the subject matter. Since opportunities for post-session assessment is limited, there is a need to effectively evaluate students’ learning in class. Kahoot, an open-source, game-based learning platform, has been used in a number of Health Sciences, Life Sciences, and Engineering library sessions at the University of Alberta. This poster, presented at the 2017 Canadian Library Assessment Workshop (CLAW) Conference in Victoria BC, provides a case study of how it was used as a formative assessment tool in a series of curriculum-based, 300-level Pharmacy seminars. Data collected from the Kahoot quizzes will be analyzed to show the effectiveness of this platform as an assessment tool. We will also demonstrate how Kahoot may be adopted for other learning environments. Kahoot allows librarians to create online quizzes (e.g. multiple choice questions) that can be used on any computer or mobile device and does not require students to create accounts beforehand, making it easily accessible. Operating like an audience response system, students select the correct response on their own devices, and results are tabulated and collected in real-time, making assessment easy. This level of assessment allows instructors to review and reinforce content based on students’ responses. For instance, if the majority of the class answers a question incorrectly, the instructor can use the opportunity to explain the concept differently or use other examples. Our findings illustrate that this program is an effective assessment tool, while also enhancing students’ engagement and understanding of classroom content. Since formative assessment in the classroom can be challenging for instructors, this poster provides examples on how Kahoot may be used in diverse learning environments.
Author/Creators:
Kung, Janice
Title:
Rational Design and Development of Nanodelivery Systems and Combination Treatments for Overcoming Chemoresistance in Solid Tumors
Description:
The long term goal of this research is to develop drug delivery systems and combination treatments that can overcome chemoresistance in breast cancer. Here, we attempted two different approaches: First, we tried development of polymeric micelles capable of enhanced drug delivery to tumor, while avoiding nonspecific drug distribution to healthy organs. Special attention was paid to the effect of core stereoregularity and chemical structure in di- as well as tri-block copolymers in the development of polymeric micellar carriers with enhanced thermodynamic and kinetic stability, high drug loading and slowed drug release. Such nano-carriers are expected to achieve improved accumulation in solid tumors through enhanced permeation and retention (EPR) effect. Synthesis of block copolymers of poly(ethylene oxide)-poly(lactide) (PEO-PLA) with different tacticity in the PLA block was pursued using either bulk or solution polymerization. This was followed by block copolymer self-assembly and micellar characterization. In diblock copolymer micelles, a positive correlation between stereoactivity of the core-forming block and degree of core-crystallinity as well as micellar kinetic and thermodynamic stability was observed. Nonetheless, the improved micellar stability neither translated to a reduced rate of drug release nor increased level of drug loading using nimodipine as a model lipophilic drug. Triblock copolymer micelles with a drug miscible inner core (evidenced by a low Flory Huggins interaction parameter); i.e., poly(ε-caprolactone) (PCL) or poly(α-benzyl carboxylate-ε-caprolactone) (PBCL), and drug immiscible outer core, i.e., PLA, improved nimodipine loading content while inhibiting its burst release from the nano-carrier. In the second part of this thesis, we investigated application of actively targeted polymeric micelles with and without modulators of relevant mechanisms of hypoxia induced chemoresistance (HICR) to cisplatin to overcome drug resistance in breast cancer at a cellular level. This study was aimed to potentiate cytotoxic effects of free and polymeric micellar cisplatin in MDA-MB-231 cells and its two subpopulations with distinct tumorigenic features. The peptide ligand of epidermal growth factor receptor (EGFR), GE11 (YHWYGYTPQNVI), was conjugated to the acetal-PEO end of acetal-PEO-Poly(α-carboxyl-ε-caprolactone) (acetal-PEO-PCCL). The polymer then formed a complex with cisplatin through its pendent COOH groups self-assembling to polymeric micelles during the process. GE11-peptide increased cellular uptake of polymeric micellar cisplatin by MDA-MB-231 cells under hypoxic condition, however the cytotoxicity of GE11-cisplatin micelles was not significantly different from plain micellar cisplatin. We then investigated the combination of free and micellar cisplatin with inhibitors of cellular pathways involved in HICR in MDA-MB-231 cells. Our results pointed to a major role for signal transducer and activator of transcription 3 (STAT3) in addition to hypoxia inducing factor-1α (HIF-1α), in the appearance of stem-cell markers and resistance to cisplatin in MDA-MB-231 cells. Hypoxia was also shown to actively convert the low tumorigenic/stem-like subpopulations of MDA-MB-231, separated based on their unresponsiveness to a Sox2 reporter (abbreviated as RU cells), to the more tumorigenic/stem-like subpopulation (abbreviated as RR cells). Evidence for the major role of STAT3 activation as responsible factors for this conversion was also revealed. The use of pharmacological inhibitors of STAT3 and HIF-1α with free, as well as polymeric micellar cisplatin (plain and GE11 modified) substantially enhanced the cisplatin toxicity and showed success in partial reversal of HICR to cisplatin. Overall, the results of our studies show the chemical structure of block copolymer based nano-carriers has the required flexibility for the development of delivery systems for certain application needs. We have shown this towards development of stable nano-carriers capable of high drug loading and slow drug release by manipulating the stereochemistry and structure of di- as well as triblock copolymer micelles. Nano-delivery systems developed to enhance drug delivery to tumor tissue may not be able to overcome chemoresistance at the cellular level, particularly since they are designed to slow down drug release and have low interaction with cells because of their hydrophilic surfaces. Our results show, the potency of conventional and nano-chemotherapeutics can be enhanced once major cellular and molecular players of chemoresistance are identified and appropriate inhibitors of the identified pathway are used in combination with the anti-cancer agent. We have shown this through identification of major players in the hypoxia-induced tumorigenic conversion and chemoresistance against cisplatin (STAT3 and HIF-1α followed by the use of genetic silencers as well as pharmacological inhibitors of the mentioned pathways in combination with free and micellar cisplatin formulations, in MDA-MB-231 cells.
Author/Creators:
Soleymani Abyaneh, Hoda
Title:
Advancing Engraftment and Cell Survival in Experimental and Clinical Islet Transplantation
Description:
Islet transplantation is today a well-established treatment modality for selected patients with type 1 Diabetes mellitus. The procedure has experienced notable refinements over the decades due the continuous efforts of clinicians and scientists to make islet isolation a reality, with a resulting final product to the highest standards, capable of safely treating patients against this autoimmune disease responsible for impaired insulin secretion and hypoglycemia unawareness. After the success of the University of Alberta group with a modified approach to the immune protection of islets, the international experience grew along with the numbers of transplants in highly specialized centers. Yet, long-term analysis of those initial results from the Edmonton group indicated that insulin-independence was not durable and most patients return to modest amounts of insulin around the fifth year, without recurrent hypoglycemia events. This thesis presents the results from multiple projects aimed to improve some of those limiting factors for prolonged islet survival. We provide sufficient background for the reader to learn about the historical perspective, along with the latest efforts to improve islet engraftment, immune protection and ultimately, long-term graft survival. We present our efforts to enhance beta cell viability and potency in vitro through added protection using the Mangano-metalloporphyrin BMX-010 during the isolation and culture process. This molecule has been reported to provide anti-inflammatory and antioxidant effects in pre-clinical transplant models. We here present an assessment of this metalloporphyrin in clinical islet transplantation. Another area of research is the avoidance of immunosuppression toxicity, which is one of the contributing factors for graft loss overtime. We specifically explored the potential cytoprotective effect of Anti-aging Glycopeptide (AAGP), a synthetic analogue of anti-freeze proteins, and demonstrated significant impairment of islets treated with high dose tacrolimus and effective protective effect from culture supplementation with the AAGP. Clinical results of islet transplantation are discussed and new immunosuppressive strategies are presented, along with quality assurance elements for the human islet preparation. In particular, we explore the possibility of microbial contamination of the preparation. Shifting focus to alternative sources for islet transplantation, we present developmental experimental studies towards the implementation of the subcutaneous space for islet and insulin-producing stem cells, which is a promising avenue of research with the potential to provide an unlimited supply for transplantation and a personalized approach to transplant medicine. Various alternatives are tested for prevascularized Cell Transplant under the skin, in experimental and clinical setting to accommodate the future implementation of stem Cell Transplant in humans. Complementary information is provided in appendices with systematic reviews on the advances of immunosuppression in islet transplantation towards the improvement of engraftment and graft durability. Moreover, a special case reports provides an opportunity to debate the practice of islet autotransplantation after total pancreatectomy. In this case, a new indication is presented in a patient with metastatic renal cell carcinoma, prompting for a new view of indication expansion when conditions allow for it. Many phenomena have been identified as limiting factor for the islet engraftment and survival, and today all efforts are aimed to improve the quality of islets and their engrafting process, as well as more optimized immunosuppression to facilitate tolerance and ultimately, better long-term survival. As the field of islet transplantation continues to progress, it is foreseeable that a cure for type 1 diabetes mellitus is obtainable in the near future.
Author/Creators:
Gala Lopez, Boris L.
Title:
Les valeurs canadiennes en contexte international: analyse de la rhétorique politique et des pratiques des multinationales canadiennes en République Démocratique du Congo (2000-2010)
Description:
  Cette étude porte sur l'écart entre l'image et l'identité internationale du Canada et la réalité des pratiques de l'État fédéral et du comportement du secteur privé canadien en Afrique, plus précisément en République démocratique du Congo. De 2000 à 2010, le Canada a connu différentes approches gouvernementales libérales et conservatrices en matière de politique étrangère. Cependant, à la lumière des relations économiques avec la République démocratique du Congo au cours de la même période, il semble que l'approche soit la même. Depuis 2000, divers rapports ont été publiés sur le pillage des ressources naturelles au Congo et le Canada a joué un rôle actif dans ce pillage, à travers ces multinationales (canadiennes) qui sont impliquées ou encore par laxisme de l’État (Canada). Ainsi : « L'identité et les intérêts de l'État canadien ne sont pas des concepts immuables ». Le mémoire se divise en un premier chapitre qui analysera l'identité canadienne au niveau international, qui se manifeste sous trois angles différents, à savoir : a) l'enchevêtrement entre les identités internes et internationales, b) la fragmentation de identités internes qui nuisent à la formation d'une identité internationale canadienne, c) en retour, l'identité internationale du Canada permet de construire une unité interne artificielle. Le deuxième chapitre mettra l'accent sur le Canada et l'Afrique : les contributions humanitaires ou au contraire basées sur l'intérêt, afin de voir quelles motivations ont toujours permis à cette puissance moyenne d'agir sur le continent africain. Enfin, le troisième chapitre mettra l'accent sur les entreprises canadiennes situées en RDC en relation avec les valeurs autoproclamées et défendues officiellement par le Canada. This study is about the discrepancy between Canada’s self-defined international image and identity and the reality of both the federal state practices and the Canadian private sector behavior in Africa, more precisely in the Democratic Republic of the Congo. From 2000 to 2010, Canada has experienced different liberal and conservative government approaches to foreign policy. However, in light of economic relations with the Democratic Republic of the Congo over the same period, it seems that the approach was the same. Since 2000, various reports were published on looting of natural resources in the Congo and Canada played an active role in this looting through these multinationals (Canadians) who are involved or the laxness of the state (Canada). Thus: “The identity and interests of the Canadian state are not immutable concepts ". In order to prove this point, the text is divided in three chapters. The first chapter is an analysis of the Canadian identity at the international level, which is seen from three different angles, namely: a) the entanglement between internal and international identities, b) the fragmentation of internal identities which is detrimental to the formation of a Canadian international identity, c) in return, the international identity of Canada allows for the building of an artificial internal unity. The second chapter is on Canada and Africa or more specifically the humanitarian or, on the contrary, the interest-based marriages of the interventions, and this chapter is written in order to see what motivations have always enabled a soft power like Canada to act in this continent. And finally, the third chapter is on the behavior of Canadian companies located in the DRC, which is in sharp contrast with the self-proclaimed Canadian values which are at the core of the internal identity.
Author/Creators:
Waka, Mamdu Patrick
Title:
Petroleum Diesel-Assisted Ambient Temperature Aqueous-Nonaqueous Hybrid Bitumen Extraction Process
Description:
Solvents are used in the oil sands industry to reduce the viscosity of bitumen and hence to assist recovery of bitumen prior to its upgrading. Solvents can also be added to the ores to reduce energy consumption during the aqueous-nonaqueous hybrid bitumen extraction process at ambient conditions. The interfacial tension and zeta potential of petroleum diesel in water were measured to confirm the presence of surface active chemicals in petroleum diesel. Functional groups of the surface active species were found to be present in petroleum diesel using fourier transform infrared spectroscopy and gas chromatography mass spectrometry techniques. The characterization techniques confirmed the presence of aliphatic compounds and aromatic compounds in the petroleum diesel, which make petroleum diesel an effective solvent as process aids for bitumen extraction from oil sands ores. Different ores were used at various petroleum diesel dosages to evaluate the performance/efficiency of petroleum diesel on bitumen extraction process from the selected types of ores. The overall extraction performance of selected ores was improved as more petroleum diesel was added to the ores prior to the batch extraction process. The addition of petroleum diesel led to higher initial rates of bitumen liberation and decreased induction time for bitumen and air bubble attachment. The results showed that the optimum addition of petroleum diesel is approximately 10% by mass of bitumen in ore. Dodecane was used as a model solvent to estimate the loss of petroleum diesel to tailings using thermogravimetric analysis techniques. The solvent loss was found to meet the specification of 4 barrels of solvent per 1000 barrels of bitumen produced. Both petroleum diesel and dodecane showed similar impact on bitumen extraction from oil sands ores. The bitumen liberation analysis showed that the reduction of bitumen viscosity is the main factor for improving bitumen recovery in the aqueous-nonaqueous hybrid bitumen extraction process. The similar performance between petroleum diesel and dodecane indicates that the natural surfactants of petroleum diesel did not play a strong role in improving the bitumen extraction from oil sands ores. The reduction in viscosity of bitumen facilitates the migration of bitumen natural surfactants to the interface as shown by lower interfacial tensions between bitumen and water, which play a strong role in bitumen liberation process.
Author/Creators:
Russell, Derek A.
Title:
The Blurred Line: Narrative and Truth in Three Colombian Crónicas
Description:
The crónica has been an important literary and cultural component in Latin America for years. Published in newspapers or magazines, these short works details true events while employing literary elements usually reserved for fiction. Today, many scholars still debate the elements of the genre as it sits in an uncomfortable grey area between literature and journalism. In recent years, many crónicas have taken up themes around drug wars and narcoculture, making this grey area even more vexed, as the authors deal with personal and national tragedies. Presenting controversial and marginalized themes from a personal perspective, the crónica establishes a raw connection between the writer and the audience. This thesis strives to determine how specific narrative elements construct intimacy of the story, specifically in crónicas of violence in Colombia. A secondary goal is to determine how intimacy strives to affect the perception of truthfulness. Does a more intimate story seem closer to the truth, or does the subjectivity limit this possibility? While this thesis cannot propel the genre into only one realm of either literature or journalism, by analyzing narrative elements in the well known crónicas “El pueblo que sobrevivió a una masacre amenizada con gaitas” by Alberto Salcedo Ramos, “Relato de un secuestrado” by Álvaro Sierra and Noticia de un secuestro by Gabriel García Márquez, this thesis helps us understand how the perception of truthfulness is constructed in a series of texts about a very real problem.
Author/Creators:
Rempel, Leanne M
Title:
OPTIMAL CROSSOVER DESIGNS IN CLINICAL TRIALS
Description:
This thesis specializes in statistical issues involving crossover designs, a very popular design in clinical trials for comparing non-curative treatments for their efficacy. The popularity stems from the fact that each experimental subject receives a sequence of trial treatments rather than one single treatment as in parallel designs, and thereby requires fewer experimental subjects. Further, it reduces variability in treatment comparisons because subjects serve as their own controls and between-subject variations are eliminated. One distinct feature in crossover designs is that the treatment assigned to subjects may have lasting effects, called carryover effects, on their responses to treatments in subsequent applications. Crossover designs are well-deliberated for its controversy involving the non-orthogonal key parameters of direct and carryover treatments, which leads to completely different experimental designs depending on which is the primary interest. There are several issues that we address in this thesis. First, when building optimal designs, there are often competing objectives that the investigator desires to optimize. These multiple objectives can include two or more parameters or some functionals, ultimately requiring simultaneous considerations. We revisit the controversy from the point of view of constrained and compound designs for better understanding. Second, we focus on the construction of optimal designs to that of individual- based designs. Typically, designs were constructed to optimize the average subjects and not ideal in clinical and medical applications. N-of-1 trials are randomized multi-crossover experiments using two or more treatments on a single patient. They provide evidence and information on an individual patient, thus optimizing the management of the individual’s chronic illness. We build one sequence N-of-1 universally optimal designs. We also construct optimal N-of-1 designs for two treatments. Then, we discuss the extension to optimal aggregated N-of-1 designs, which will be optimal for an overall treatment effect. Third, we extend the response adaptive allocation strategy for continuous responses to construct those for binary responses with the goal of allocating more patients to better treatment sequences without sacrificing much estimation precision. Although design efficiency in terms of mean squared error may drop sharply, increase in allocated patients to the treatment with beneficial effect is evident. We show a balance can be achieved between various competing multiple objectives. Fourth, we advocate the convex optimization techniques to construct optimal crossover designs where analytic solutions are not feasible. Upon identifying the unique problems and conditions for constructing optimal designs to that of the convex optimization problem, we apply them to find optimal designs relatively simply.
Author/Creators:
Li, Yin
Title:
Identification of biomarkers associated with the onset and progression of ketosis in transition dairy cows
Description:
Ketosis is a common metabolic disorder of transition dairy cows during the early lactation period. Cows with ketosis have lower milk yield and reproductive performance, greater risk of other periparturient diseases, and higher culling rate. Although ketosis has been extensively studied, not many investigators have focused on the pathobiology of the disease over time. Previous work has been mainly concentrated on the diagnosis, epidemiology, and implications of ketosis around the transition period. There is a grey area with regards to the agents that initiate ketosis and the metabolic pathways involved in the pathobiology of the disease. Moreover, not very much is known about how to prevent ketosis. Most work has been focused on the treatment of ketotic cows. It would be of great interest to both the dairy industry and health specialists to detect ketosis as early as possible and to take appropriate preventive measures. Therefore, the principal objectives of this thesis are: 1) to find evidence of the involvement of innate immunity in the pathobiology of ketosis as well as changes of in carbohydrate and lipid metabolism in pre-ketotic, ketotic, and post-ketotic cows; 2) to determine blood and urine metabotypes of transition dairy cows before, during, and after occurrence of ketosis; and 3) to identify new screening or predictive metabolite biomarkers of ketosis in the serum and urine of dairy cows as early as 8 weeks before the expected day of parturition. To achieve these objectives, an enzyme linked immunosorbent assay (ELISA) was utilized to quantify and compare selected pro-inflammatory cytokines [i.e., inerleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor (TNF)], as well as acute phase proteins [(APP), i.e., haptoglobin (Hp) and serum amyloid A (SAA)] in the serum of cows diagnosed postpartum with ketosis and healthy controls (CON) starting at -8 and -4 wks before parturition, during the week of disease diagnosis as well as at +4 wks after calving. We also used several metabolomics tools including direct injection/liquid chromatography-tandem mass spectrometry (DI/LC-MS/MS), proton nuclear magnetic resonance (1H-NMR), gas chromatography-mass spectrometry (GC-MS), and inductively coupled plasma-mass spectrometry (ICP-MS) to quantify and compare metabolites from various analyte groups including amino acids (AAs), acylcarnitines, biogenic amines, glycerophospholipids [i.e., phosphatidylcholine (PC) and lysophosphatidylcholine (lysoPC)], sphingolipids [i.e., hydroxysphingomyelin: SM (OH) and sphingomyelin (SM)], hexose, organic acids, saccharides, ketones, alcohols, mineral elements, and others, in the serum/urine of pre-ketotic (-8 and -4 wks), ketotic (disease wk), post-ketotic (+4 and +8 wks), and CON cows. Results of this study indicate that cows affected by ketosis display alterations of multiple variables of innate immunity as well as amino acid, carbohydrate and lipid metabolism several weeks prior to the diagnosis of the disease. Two sets of predictive biomarker models and one diagnostic biomarker model for ketosis with high sensitivity and specificity were identified in serum and urine, respectively. These newly identified sets (two from serum and two from urine) of ketosis biomarkers can predict the disease much earlier than measurement of ketone bodies during early lactation. Results also demonstrated that cows with ketosis experienced lower dry matter intake (DMI), elevated milk somatic cell count (SCC), and a tendency for lower milk production, and lower milk fat.
Author/Creators:
Zhang, Guanshi
Title:
State Estimation and Servo-control of Distributed Parameter Systems
Description:
The dynamics of many chemical and mechanical processes are influenced by both temporal and spatial factors and these processes are called distributed parameter systems (DPS). Moreover, their mathematical models are given by partial differential equations (PDE) and they belong to infinite-dimensional systems. Due to the existence of the spatial variable in the mathematic model, the state estimation and control of the distributed parameter systems are interesting and challenging. The focus of this thesis is to develop the optimal state estimation method and servo-control (output regulation) methods in the optimal and internal-model framework. To address the control problems for finite and infinite dimensional systems, the full state information is usually necessary. In this thesis, an optimal state estimation method is developed for spectral distributed parameter systems to account for full state estimation problems with state constraints due to physical limitations. In particular, a modal decomposition technique is applied to reduce the order of the considered dissipative systems that are assumed to satisfy the decomposition assumption. With the full state information of the control systems, the proposed servo-control approaches in this thesis are able to implement. In this thesis, two types of servo-control (output regulation) are considered: Internal Model Control (IMC) and Optimal control. In fact, the servo-control includes two aspects: stabilization and reference signal tracking. In the aspect of the stabilization, an operator Riccati equation approach and a weak variational optimal method are developed for the first order hyperbolic PDE systems in this thesis. For the aspect of the reference trajectory tracking, novel output feedback and error feedback regulators are developed to deal with the distributed and/or boundary tracking control problems for general distributed parameter systems. Finally, the servo-control problems for the countercurrent heat exchanger, the plug flow reactor and the solar-thermal district heating system are addressed in the application part of this thesis. In particular, for the countercurrent heat exchanger, the proposed output regulation approach is applied; for the plug flow reactor, the proposed weak variational optimal stabilization and the output regulation method are combined and applied; and for the solar-thermal district heating system, the receding horizon optimal control and the output regulation approach are implemented to solve the energy maximization and the reference tracking problems.
Author/Creators:
Xu,Xiaodong
Title:
Landslide Risk to Railway Operations and Resilience in the Thompson River Valley near Ashcroft, British Columbia
Description:
This thesis investigates the hazard frequency and associated risk posed by twelve large landslides in the Thompson River Valley south of Ashcroft, British Columbia, which are collectively referred to as the Ashcroft Thompson River landslides. The Canadian National and Canadian Pacific railways operate busy main lines within the subject 10 kilometer corridor south of the village of Ashcroft, traversing the lower portions of many of the landslides. These landslides have resulted in significant, recurring disruptions to Canada’s Class 1 railways, and affect numerous other groups located within the valley, including First Nations communities, residents of the villages of Ashcroft and Spences Bridge, salmonid populations within the Thompson River, and owners/operators of upland agricultural areas. While the Ashcroft Thompson River landslides are typically inactive or very slow moving, numerous periodic reactivations have been documented in the past 150 years, some of sufficient magnitude to temporarily dam the Thompson River. The objectives of the research are to characterize the risks posed by the Ashcroft Thompson River landslides to the Canadian railway network and to the numerous stakeholders in the Thompson River Valley, and to investigate strategies for managing the risks and improving the overall resilience of the system. The research methodology includes an examination of the history and ongoing activities of the landslides, with an emphasis on the dynamic climatic and anthropogenic factors which have contributed to the slope movements over time. Recent landslide activity in the corridor is correlated to snow pack and stream flow in the Thompson River basin. Trends in the discharge of the Thompson River over the past century are, in turn, related to the phase of the high-level climate phenomenon termed the Pacific Decadal Oscillation (PDO). An awareness of the interannual and interdecadal fluctuations in climate regimes and their hydrologic implications is presented as an essential component for contextualizing historic landslide frequency and future landslide risk. The anticipated hydrologic impacts of climate change and their potential effects on landslide activity in the corridor are also discussed. The qualitative risk assessment which follows distinguishes the different modes of failure which have been demonstrated by the landslides in the corridor, to elucidate the unique causal factors, consequences and associated risk scenarios. A risk management strategy is presented which integrates an understanding of climate factors which may portend landslide activity in the corridor, a kinematic understanding of the landslide failure modes, and an observational approach to geotechnical monitoring and inspection. It is recommended that contemplated risk reduction measures favor flexible options which would be suited to a range of future climate conditions, improve adaptive capacity through more effective anticipation and forward planning, and integrate active monitoring and regular site inspections of slope movements with effective strategies for the documentation, communication and dissemination of hazard and risk information. The economic consequences of a landside which impacts the railway infrastructure in the Thompson River Valley can grow exponentially with the duration of the outage; given the diverse cross-section of stakeholders involved, the consequences of a rapid landslide in this corridor may also include significant safety, environmental, and cultural impacts. The application of a resilience paradigm for managing critical infrastructure and enhancing a community’s ability to cope with disruptions is presented in the context of the Ashcroft Thompson River landslides. The high-consequence, low-probability nature of a rapid landslide necessitates a flexible, resilient response by all stakeholders. To this end, case studies summarizing and evaluating the risk communication and public involvement efforts in the District of North Vancouver, British Columbia, and Canmore Alberta, are presented to convey lessons learned and highlight current best practices stakeholder involvement in risk management and decision making. It is hoped that the research contributions in the area of risk management and system resilience will impact how Canada’s railway industry and its regulator will monitor and mitigate landslides along the Thompson River Valley, with broader implications for the risk management of natural hazards interacting with the built environment.
Author/Creators:
Tappenden, Kristen M
Title:
Regulation of the Na+/H+ Exchanger 1 by BRAF Kinase
Description:
Mammalian Na+/H+ Exchanger 1 is a ubiquitously expressed membrane protein, which is dedicated to maintaining the acid-base balance in the cell. This balance is brought about by the exchange of one intracellular proton in exchange for extracellular sodium ion. NHE1 is the predominant isoform found in the myocardium and has been implicated in several cardiac diseases including cardiac hypertrophy and ischemic reperfusion induced injury. The NHE1 C-terminal domain is made up of 315 amino acids and is subject to regulation by several protein and protein kinases including the BRAF kinase. In our study we have demonstrated that the BRAF kinase binds to NHE1 C-terminal tail within a region encompassed by amino acids 634 to 710. We also demonstrate that BRAF kinase co-localizes with NHE1 in both AP1 cells as well as HeLa cells, in a serum-dependent manner and the withdrawal of serum results in a loss of co-localization between the two proteins. We further evaluated the role of the threonine 653 amino acid (a target of BRAF kinase phosphorylation) on the NHE1 C-terminal tail with respect to cell proliferation. Mutation of the residue to a non-phosphorylatable amino acid led to a reduction in the rate of cell proliferation. Additionally, we examined the role of BRAF-NHE1 interaction in melanoma and its effects on various cellular processes. We used specific inhibitors of wild type BRAF (SB590885), mutant BRAF (PLX4720) and NHE1 (EMD87580 and 5-(N,N-Hexamethylene) amiloride (HMA)) either alone or in combination to elucidate the role of BRAF-NHE1 interaction in M19, IF6, FM82 and Mel2A human melanoma cell lines. NHE1 did not affect the melanoma cell lines’ ability to proliferate. Migration was significantly reduced in the presence of inhibitors. A combination of BRAF inhibitor and HMA led to a small but significant effect on the rate of migration when compared to NHE1 or BRAF inhibition alone. Invasion was also significantly reduced in the presence of NHE1 or BRAF inhibitors. We also observed varying levels of vimentin among the four cell lines with M19 and Mel2A having high levels of this protein. Mature NHE1 protein was observed only in FM82 and Mel2A but not in M19 or IF6 cell line. These results highlight the importance of NHE1 in the various cellular events associated with tumorigenesis and give a better insight into the underlying mechanism. We further investigated the role played by stop codon polymorphisms (SCP) in NHE1 localization. We looked at four different SCPs namely, 735STOP, 543STOP, 449STOP and 321STOP. 735STOP localized to the plasma membrane (similar to wild type NHE1) while the other three mutants had cytosolic localization. This study provides us with a better understanding of the vital role played by NHE1 C-terminal tail and how these SCPs can cause deleterious effects within the cell.
Author/Creators:
Augustine, Aruna M
Title:
EXPERIMENTAL INVESTIGATION OF THE SETTLING VELOCITY OF SPHERICAL PARTICLES IN VISCOELASTIC FLUIDS
Description:
Knowledge of settling behavior of particles in various types of fluids is indispensable to design and optimize numerous industrial operations such as cuttings transport in oil and gas well drilling, proppant transport in hydraulic fracturing operations, and so on. Most of the models developed so far were to predict settling velocity of particles in either Newtonian or purely viscous non-Newtonian shear thinning fluids where there were no considerations of the fluid elasticity effect. Therefore, these models are not suitable for settling velocity prediction when the process involves fluids of viscoelastic nature such as drilling and hydraulic fracturing fluids. The main objective of this study is, therefore, set to determine how the fluid shear viscosity and the elasticity would influence the particle settling velocity and even more so to answer the question of which one of these two rheological properties is more dominant in controlling the particle settling velocity when viscoelastic drilling fluids are used. The settling velocities of the spherical particles (diameters: 1.18, 1.5, 2 and 3mm) in partially hydrolyzed polyacrylamide (HPAM) polymer fluids were measured by using Particle Image Shadowgraph (PIS) technique. Two sets of test fluids were formulated by mixing three different grades of HPAM (molecular weights of 500,000; 8,000,000; and 20,000,000) at polymer concentrations 0.09%, 0.05% and 0.03% wt. The shear viscosity and elasticity characteristics of test fluids were determined by performing shear viscosity and frequency sweep oscillatory measurements, respectively. The first set of fluids had almost identical shear viscosity characteristics while showing significantly different elastic properties. The second set of fluids had similar elastic properties but different shear viscosity characteristics. Experimental results showed that: (i) When the fluids having similar shear viscosity profile were used, the settling velocity of spherical particles decreased significantly with the increasing fluid elasticity. Comparison of the experimental results against the values calculated from the model developed for predicting the settling velocity of spherical particles in power law (visco-inelastic) fluids have shown that the settling velocity values can be 14 to 50 times over-estimated if the effect of the elasticity is not considered; (ii) At constant elasticity, the settling velocity of spherical particles also decreased significantly when the fluid shear viscosity was increased; (iii) The spherical particles settling velocity increased pronouncedly as their diameter increased from 1.18mm to 3mm. But the magnitude of the increase in settling velocity with the increasing particle diameter is less for the samples having higher elasticity and similar shear viscosity characteristics. A follow up experimental study has been conducted to understand the reasons behind why the settling velocity of the particles decrease with the increasing fluid elasticity. In this case, the main objectives were: (i) to investigate the fluid flow field behind the settling particle by using particle image velocity (PIV) technique; (ii) to understand the changes caused by the elasticity of the fluid on the flow field past the settling particle; (iii) more specifically, to determine how the fluid velocity profile and the resultant drag forces acting on the settling particle change with the increasing fluid elasticity. Two sets of viscoelastic fluids were formulated by mixing three different grades of partially hydrolyzed polyacrylamide (MW of 500,000; 8,000,000; and 20,000,000) at polymer concentrations of 0.09%wt and 0.1%wt. The viscoelastic fluids were formulated in such a way that they had almost identical shear viscosity but significantly different elastic properties. The fluid flow field (i.e. near particle velocity profile) behind the settling particle was determined by using the PIV technique. The results of the PIV measurements demonstrated that negative wake was present in viscoelastic fluids. However, the stagnation point (the point at which fluid velocity becomes zero and above that the fluid starts moving in the opposite direction to the particle movement) was closer to the particle settling in the higher elasticity fluid than that in the lower elasticity fluid. The velocity of the fluid in the recirculation region was higher for the flow of the fluid with higher elasticity. Therefore, the presence of stronger negative wake having fast moving fluid in reverse direction nearer to the settling particle could possibly create higher drag forces (acting in the direction against the particle movement), which would affect the settling velocity of the particle.
Author/Creators:
Arnipally, Sumanth Kumar
Title:
Structural Reliability of Non-Slender Loadbearing Concrete Masonry Members under Concentric and Eccentric Loads
Description:
Although the reliability levels of structural steel and reinforced concrete structures designed to the Canadian codes and standards have been investigated substantially in the past four decades, studies on the reliability of masonry structures are limited. Based on some preliminary studies in 1980s, the design of masonry structures using the limit states method was introduced in the 1994 edition of the Canadian standard S304 in order to provide more uniform and economical design guidelines. However, the limit states design criteria were not supported by a rigorous reliability-based analysis. The investigation reported herein was carried out to contribute to filling the gap in our knowledge on the reliability of structural masonry members designed using the limit states method, to establish reliability levels for masonry comparable to other structural materials and to help remove any unnecessary conservatism in the masonry design process. The first order reliability method was used to assess the reliability of unreinforced and reinforced non-slender concrete masonry walls under combined axial load and out-of-plane bending. In this research, only non-slender walls having a slender ratio (kh/t) not requiring consideration of second order effects are considered. Nevertheless, the procedure for performing the reliability analysis for walls with larger kh/t is proposed and explained.
Author/Creators:
Moosavi Nanehkaran, Seyed Abdol Hadi
Title:
Health Technology Management and Canada's Medical Devices Special Access Program
Description:
Health Technology Management (HTM) encompasses a broad array of processes spanning technical, clinical, and administrative disciplines in order to optimize the efficient use of healthcare resources. It employs a ‘lifecycle’ approach, evaluating technologies at each stage of maturity from concept through use and finally discontinuance. Health technologies exist in various forms; one of them being medical devices. In Canada, medical devices are controlled through the federal Food and Drugs Act and Regulations. While most medical devices require licensing to be sold in the market, provisions exist in the regulations for healthcare professionals to access unlicensed devices. One mechanism is through application to Health Canada’s Medical Devices Special Access Program (MDSAP). This thesis examined the MDSAP in order to understand its role in HTM. Three separate, yet related studies, were conducted. The first study employed a scoping literature review to determine the landscape of available information and to identify more focused areas of required research. The second study reviewed two cases to determine why and how the MDSAP was used to obtain devices in a hospital setting. The third study conducted key informant interviews to compare and contrast key stakeholder perspectives on roles and responsibilities, knowledge and information needs, and program utilization. Each study employed qualitative content analysis to generate findings. The scoping study determined that the literature was generally limited, yet suggested the MDSAP roles in HTM are: as an arbiter in technology selection, as a route to technology procurement, and as a facilitator of health technology innovation. The two-case study determined the MDSAP was used for the introduction of new health technology, which comprised 5 general processes: Technology Development, Knowledge Transfer, Evaluation, Acquisition, and Patient Management, and the program played an essential role in the Acquisition stage for the two novel technologies under consideration. Four drivers of program use were identified. These were: change agents, clinical need, innovation, and new evidence. The combination of driving forces triggered the sequence of processes. The MDSAP is a regulatory policy that impacts the management of health technology. It can result in the accelerated replacement of existing technology, organizational change, and innovation in the development of best clinical practice. The study on stakeholder produced four themes: the MDSAP authorizes access to needed medical devices, physicians drive MDSAP demand in the interest of patient care, global forces impact the MDSAP, and the improved management of health technology is a priority need. This study suggests HTM’s next steps should include initiatives that enhance the collection and dissemination of unlicensed medical device data. The three studies’ findings were aligned. They inform components of the four major stages of the technology lifecycle – premarket, adoption, real-world use, and decommissioning – and demonstrate the role and impact of the MDSAP in HTM.
Author/Creators:
Maier, Roland K
Title:
A Defense of Bertrand Russell’s Theory of Definite Descriptions against Donnellan’s Distinction
Description:
According to Russell’s theory of descriptions, a sentence of the form “The F is G” expresses the general proposition There is exactly one F and whatever is an F is G. According to Donnellan, there are two types of uses of a definite description: an attributive use and a referential use. A definite description is said to be used attributively when a speaker intends to assert something about whoever or whatever fits the description “the F”. In that case “The F is G” expresses there is exactly one F and whatever is an F is G. On the other hand, a definite description, according to him, is said to be used referentially when a speaker uses a sentence containing that definite description to state something about a particular object, o, the speaker has already had in mind. In such a case the sentence “The F is G” expresses the proposition o is G. Thus, a sentence of the form “The F is G” is ambiguous, it has two sorts of meaning: an attributive meaning and a referential meaning. Based on the ambiguity mentioned above Donnellan claims that Russell’s theory is incorrect as it fails to accommodate the referential meaning of sentences containing definite descriptions. In this thesis, I defend Russell’s theory against the problem arising from Donnellan’s distinction. I show that Donnellan’s distinction doesn’t posit a genuine problem for Russell’s theory in either way: (a) neither is a sentence containing a definite description ambiguous, i.e. it has always one lexical meaning; (b) nor does Russell’s theory deny the pragmatic significance of a sentence containing a definite description. In support of (a), (i) I focus on the distinction between semantics and pragmatics and argue that the existence of convention alone cannot be a sufficient condition for determining the semantic meaning of a sentence, rather the semantic meaning of a sentence is the literal meaning which is defined by a dictionary and the grammar of a language. (ii) I refute Michael Devitt’s arguments for the semantic significance of referential definite descriptions based on the regularity of using referential descriptions, and the similarity between the function and mechanism of determining the referents of “the F” and “that F”. And (iii) I defend Kripke, who claims that Donnellan’s distinction can be explained by a general apparatus of speech acts, by showing that the general proposition There is exactly one F and whatever is an F is G is the literal meaning or what is said by “The F is G”, whereas the singular proposition o is G, expressed by “The F is G”, is a generalized conversational implicature which is derived in virtue of the meaning of the words used in the utterance of “The F is G”, though o is G is different from the literal meaning of “The F is G” (i.e. There is exactly one F and whatever is an F is G). In support of (b), I focus on the intention and significance of Russell’s theory of descriptions. I argue that Russell’s theory of definite descriptions is a theory of denotation; and hence it is a theory of semantics, and not of pragmatics, whereas the distinction Donnellan offered is an issue of pragmatics. So, a pragmatically significant theory like Donnellan’s cannot posit a genuine problem to a semantic theory like Russell’s.
Author/Creators:
Sultana, Nasrin
Title:
Study of thin liquid film drainage in bubble-liquid-solid systems using integrated thin liquid film force apparatus (ITLFFA)
Description:
Interactions involving deformable surfaces reveal a number of distinct physicochemical characteristics that do not exist in interactions between rigid solid surfaces. The main focus of this thesis is to develop a unique fully custom-designed instrument, referred to as an integrated thin liquid film force apparatus (ITLFFA) to investigate interactions between a deformable and a solid surface in liquids. Incorporating a bimorph force sensor with interferometry, the ITLFFA allows simultaneous measurement of the time-dependent interaction forces and the corresponding spatiotemporal film thickness of the intervening liquid film. The ITLFFA possesses specific features of measurement under a wide range of hydrodynamic conditions, with a displacement velocity of deformable surfaces ranging from 2 μm/s to 50 mm/s. Equipped with a high speed camera, the results of a bubble interacting with hydrophilic and partially hydrophobic surfaces in aqueous solutions indicated that ITLFFA can provide information on interaction forces and thin liquid film drainage dynamics not only in a stable film but also in films of quick rupture process. The weak interaction force was extracted from a measured film profile. As a result of its well-characterized experimental conditions, ITLFFA permits the accurate and quantitative comparison/validation between the measured and calculated interaction forces and temporal film profiles. Using the ITLFFA, the dynamic drainage process of the liquid film trapped between an air bubble and a flat silica surface over a wide range of hydrodynamic conditions was studied in aqueous solutions of different salt concentrations. Our study demonstrates that increasing the bubble approach velocity has a significant impact on the hydrodynamic pressure and fluid flow within the draining film, promoting the dimple formation and increasing drainage time. The drainage time also depends on the competition between the electrical double-layer and van der Waals interactions, which are repulsive in our system, resulting in a stable liquid film on the hydrophilic surface, with the film thickness being determined by the balance of capillary pressure of the bubbles with the repulsive forces of the film scaled by the electrolyte concentrations. The evolution of the draining film is analyzed using the Stokes-Reynolds-Young-Laplace (SRYL) model. Comparisons between the theory and experimental results indicate that the model captures essential physical properties of the drainage system. Moreover, the thickness of the first occurrence of the dimple can also be precisely predicted from the bubble approach velocity with a simple analytical expression. The dynamic thin liquid film drainage between a bubble and a hydrophobic solid surface of different hydrophobicities with nanoroughness was also studied using this device. For a given bubble approach velocity, the thickness of the first occurrence of the dimple for the hydrophobic surface was much thinner than that of the hydrophilic surface, indicating an apparent surface mobility on the hydrophobic surface. The experimental results were modelled by the SRYL model to obtain the degree of surface mobility for the hydrophobic surface as a function of bubble approach velocity, illustrating a velocity dependent surface mobility. Moreover, the thin film ruptured at thickness as large as hundreds of nanometers. The major contributions to science of this thesis are developing a device-ITLFFA that performs the simultaneous measurement of dynamic forces and spatiotemporal film thickness during thin liquid film drainage between deformable and solid surfaces. It allows measurements over a wide range of hydrodynamic conditions that fills the experimental gap of current techniques. The systematic study of the effect of approach velocity and surface hydrophobicity on the drainage dynamics of thin liquid films appealed us to consider them as vital parameters in the theoretical model that shed light on the problem of boundary condition and hydrophobic interaction.
Author/Creators:
Zhang, Xurui
Title:
The Influence of Bookshop Printing on the Creation of the Sequels to the Romance of the Three Kingdoms
Description:
In the Ming (1368-1644) and Qing (1644-1912) dynasties of China, there was a close relationship between the printing industry and the creation of novels. The commercialization of novels, free from strict cultural policies, began in about 1522, the first Jiajing year of the Ming dynasty. This trend reached a peak during the Wanli era (1573-1620), reflected by bookshop printing houses, owned by booksellers, that primarily focused on the printing, publication, and sale of novels. Between the mid-16th century and the early 17th century, reader demands and scarcity of material encouraged commercial publishers to become amateur writers themselves. As the popularity of novels increased, more literary authors devoted themselves to writing novels, allowing booksellers to concentrate on publication and transmission while still recruiting professional and experienced writers. Commercial publishers in the Ming-Qing dynasties notably contributed to popular literature (tongsu wenxue) in its early stage, especially the rise of historical and supernatural novels (shenmo xiaoshuo). These publishers and their works not only satisfied Ming-Qing audiences’ need for leisure reading but also stimulated interactions among and the evolution of different genres. The creation of the three early sequels to the Sanguo yanyi 三國演義 [Romance of the Three Kingdoms] (hereafter referred to as the Three Kingdoms) – the Xu Sanguo yanyi 續三國演義 [Continuation of the Romance of the Three Kingdoms], the Dongxi jin yanyi 東西晉演義 [Romance of the Eastern and Western Jin Dynasties], and the Hou sanguo Shi Zhu yanyi 後三國石珠演義 [Romance of Shi Zhu after the Three Kingdoms] – was influenced by commercial publishers. Many previous scholars have paid attention to the relationship between commercial publishers and novels in terms of circulation and formation, but there has not been sufficient attention to the sequels to the Three Kingdoms. My study situates these three texts within the Ming-Qing print culture, examines the strong commercial purposes behind these texts, and argues that the popularity of historical novels since the mid-Ming dynasty was not solely due to the success of the Three Kingdoms, but also because Ming commercial publishers created materials that catered to popular taste of the time. Historical novels simplified official history in order to distribute it among less-educated, and even unlearned, audiences, expanding both readership and market. History, once reserved for the elite, became a common subject of popular fiction from the mid-16th century onward. The use of simplified classical language (Wenyan) or vernacular (Baihua), reading aids such as annotations and illustrations, and commentaries all contributed to the creation of a public, distinct from an elite, reading community. Moreover, the disordered society of the late Ming created a desire for the Confucian values of benevolence, morality, and sage-kings, which are often stressed in historical novels, and also highlighted social problems and dynastic changes. However, in the mid-17th century, the dynastic change from the Ming to the Qing lessened readers’ interest in political struggles; as well, with the maturing of book-shop novels, commercial publishers began producing a variety of genres and later combined genres, so that crime-case novels, supernatural novels, gentlemen-beauty novels, and story-telling novels competed in the marketplace against historical novels. Thus, early Qing historical novels, such as the sequels to the Three Kingdoms, tended to be mixed with other popular genres and were sometimes even overshadowed by imported features, in order to meet the new demands of the market.
Author/Creators:
Chen, Zhuorui
Title:
Advances in Active Resonator based Planar Microwave Sensors for Material Characterization
Description:
Microwave planar resonators have been used for material characterizations for the past two decades. Among the many advantages from planar sensors, some of the main drawbacks are discussed and the relevant methods are provided to tackle them through this thesis. Generally, unique characteristics of microwave sensors such as the ability to perform non-intrusive real-time measurements makes them very appealing for chemical characterization. This becomes more interesting for harsh environment as it has very simple interface. Inherent associated challenges in microwave resonant based sensing are sensitivity and selectivity. Recently, the sensitivity issue has been addressed in our group to eliminate such problem by developing high resolution microwave sensors. In this thesis, we focus on advancing such sensors and further investigating their sensitivity and selectivity related challenges. To design high resolution sensor a passive microwave resonator is embedded within a regenerative circuit to provide negative resistance and remove the loss of the system. The resultant high-quality factor sensor is able to track highly sensitive measurements such as Nano-particles, e.g. Asphaltene based model-oils. In this study, precipitation and deposition of the Asphaltene at 1.2 GHz is measured and showed that it is concentration-dependent when mixed with a precipitant element, e.g. n-Heptane here. In the second step, two pairs of ultra-wideband high gain slot bow-tie antenna are exploited to accompany the sensor and remove any wired connection with the measuring device. Single-layered antennas are designed to offer 5dB gain over the bandwidth of 1.35-2 GHz, with whose installation, the quality factor of the sensor becomes Q ≈22000. Common chemicals such as IPA, acetone, ethanol, methanol, and water are analyzed with wireless communication. Salt-water wall with concentration of 0.003125 g/ml – 0.1 g/ml is used as the lossy medium, and the sensor’s bare response could also be captured.In the next step, the unwanted environmental impacts on sensing are considered as erroneous factors needed to be removed for robust measurements. Hence the single active resonator is developed into dual active sensor with enhanced functionality in tracking environmental effects. Dual uncoupled active Split Ring Resonators (SRRs), are enhanced in Q-factor from 51 and 54 up to 150k and 210k at 1.365 GHz and 1.6 GHz, respectively. The effect of humidity in sensing material under test (MUT) is calibrated out and more reliable sensing characteristics can be evaluated regardless of the uncontrollable ambient conditions. Based on the proposed technique, root of mean-square-error of processed results of measuring water in humid air was significantly reduced from 169k down to 27k. Common liquids are detected within moist sand environment successfully and the material impact is completely distinguished from that of the moist sand. It is also shown that the dual active resonator can be used in unique configuration for other applications, for instance to analyze the dispersion coefficient (k) of Nano-particle suspensions inside solutions. The measured k for Asphaltene in Heptane is consistent with the values reported in the literature. Dispersion of Asphaltene Nano-Particles in n-Heptane is measured in wide range of 0.000625-0.625 (%wt) Asphaltene : Toluene. Dual active resonator is designed at independent frequencies of 1.03 GHz (fL) and 1.149 GHz (fH). With the frequency shifts (ΔfL, ΔfH), average flow rate, and the inner diameter of the tube, the molecular diffusion coefficient, and then the dispersion coefficient can be rapidly derived according to two-window solution of Taylor-Aris dispersion analysis. Samples with higher concentration of Asphaltene are shown to have faster spread and larger dispersion in the flow. Dispersion coefficients of the samples cover the range of 5.2 -7 -4 2 ×10 mm /s in great agreement with conventional methods. In the last impactful attempt to improve the sensitivity of the sensor, mixing behavior of the sensor in its oscillatory mode is exploited, where it’s output combined with an additional signal is shown to produce intermodulation products. Intermodulation (IM) of the sensor’s two independent sources in this configuration magnifies the variations in the sensing element arbitrarily and commensurately with IM product order. The resulting structure, then provides sensitivity much larger than the primary signal. The improvements are all into effect in the final design of mixer-based sensor where wireless communication is also applied. Common fluids such as Toluene, IPA, Methanol, and Water are tested in fluidic channel and demonstrated that the sensitivity for intermodulation products are significantly increased.
Author/Creators:
Abdolrazzaghi, Mohammad
Title:
The role of microtopography in the expression of soil propagule banks on reclamation sites
Description:
Legacy propagule banks of salvaged topsoils are excellent sources of plant propagules for reclamation of mine sites. However, prior studies show that less than 50% of species found in original propagule banks actually establish. We hypothesize that the expression of this legacy propagule bank is limited by a lack of diversity of microsites and appropriate growing conditions. In an operational-scale field experiment we manipulated topographical characteristics and substrate materials and explored early vegetation establishment on an east- and south-facing slope. Three different site treatments with different microtopographic characteristics: (i) levelled surface, (ii) parallel ridges, and (iii) large loose piles were created using salvaged upland and lowland forest floor soil material. Placing materials in loose hills and providing heterogeneity in substrates more than doubled plant abundance, species richness, and increased the proportion of species that require higher soil moisture. However, the site’s overall slope aspect had a modulating effect on microtopographic treatments, with the greatest treatment effect on species richness and plant abundance occurring on the east-facing slope, while the greatest effect of treatment on the proportion of species requiring higher soil moisture was observed on the south-facing slope. Lower micro-elevations and northern microaspects of the microtopographic structures had higher soil water content, species richness and plant abundance. Micro-elevation had the greatest effect on expression of vegetation on hills constructed from cover soil salvaged from upland forests, while microaspect affected vegetation the most on hills constructed from cover soil salvaged from low-lying areas. Variability in microtopography and substrate can create favourable growing conditions that help express a wider range of species from the legacy propagule bank at operational scale.
Author/Creators:
Melnik, Katharine O
Title:
Stratigraphic and Structural Relationships in the Foreland Basin and Humber Arm Allochthon on Port au Port Peninsula, western Newfoundland
Description:
Port au Port Peninsula, in western Newfoundland, sits at the western edge of the Appalachian orogen. Middle Ordovician foreland basin strata deposited on the Laurentian margin are primarily derived from, and overridden by, Cambrian to Ordovician deep-water rocks previously mapped as mélange and assigned to the Humber Arm Allochthon. Abrupt thickness changes in the foreland basin are associated with high-angle faults and increased accommodation space in the hanging wall of extensional faults. Foreland basin strata are found between two packages of Humber Arm Allochthon on Port au Port Peninsula; they unconformably overlie the lower, allochthonous, West Bay Thrust Sheet and are overlain in turn by the upper, allochthonous, Lourdes Thrust Sheet. The West Bay Thrust Sheet was emplaced during a period of Taconian extension as an overextended and thinned wedge emplaced rapidly during the Middle Ordovician. Down-dropped along normal faults, the West Bay Thrust Sheet was covered by foreland basin strata; further Acadian (Devonian) deformation duplicated the Humber Arm Allochthon on Port au Port Peninsula to fill a tectonic wedge within the foreland basin. Taconian, extensional faults were reactivated; map offsets and slickenlines suggest two phases of reactivation which are related to Acadian inversion and Carboniferous strike-slip. The Humber Arm Allochthon comprises the Cooks Brook, Middle Arm Point and Eagle Island formations, and is structurally highly disrupted. Outcrop-scale disruption is assigned a value from 0-V with I-IV constituting broken formation and V constituting mélange. More coherent, folded outcrops of allochthonous rocks show three fold generations; early tight to isoclinal folds are overprinted by two later deformation events which we link to Acadian (Devonian) orogenesis and inversion, and subsequent Carboniferous strike-slip along high-angle faults. Mélange, representing the highest disruption mapped in the area, commonly contains igneous blocks from a variety of sources which we link to olistostromal processes at the early Taconian deformation front. Measured blocks within mélange range from thin-section scale (0.5 mm) to 150 cm. Mélange at outcrop scale shows, on average, 24% blocks to 76% scaly shale. Oriented thin sections collected from mélange show both clockwise and counterclockwise oblique-shear fractures as well as hydrocarbons. Autobrecciation, dewatering structures and sandstone dykes imply high fluid pressures. We suggest that the allochthon underwent coaxial extension within an overall compressional setting as a result of high fluid pressure; due, in part, to the expulsion of hydrocarbons from allochthonous source rocks within the wedge. This resulted in rapid forward movement (and thinning) of the Taconian wedge.
Author/Creators:
Lacombe, Ryan A
Title:
Towards a Comparison of the Folding of Prion Protein from Different Species
Description:
The formation of an abnormal form of proteins in cells can cause aggregation and neurodegenerative pathology, such as Alzheimer’s, Parkinson’s and prion diseases, which affects both humans and animals. Nowadays, the understanding of the mechanism of prion misfolding and propagation, including effective ways of treating prion diseases, is not clearly identified. This may result from the complexity of the biological ensembles. Optical tweezers, one of the single-molecule force spectroscopy methods, can be used to better understand mechanisms of protein misfolding and dynamics by manipulating small beads attached to single protein molecules, resulting in the mechanical denaturation of protein structure. Previous work studying the mechanical denaturation of structure in hamster prion protein (PrP) by laser tweezers, for example, found that the folding pathways of the native protein were composed of two states of folding and unfolding (Yu et al., 2012; 2013). Although the sequence of PrP is very highly conserved between species, there are a few differences in amino acid residues between PrP in different species. Furthermore, mouse PrP, a model system for studying prion diseases, has a lower susceptibility to the misfolding underlying prion diseases than hamster PrP. Thus, the differences in the protein sequences may lead to differences in the folding and misfolding which may relate to the different susceptibilities. This work is the first single-molecule study of mouse PrP folding; the prion proteins from mice were attached to DNA handles using click chemistry and were studied by optical tweezers in order to compare my results to those of the previous studies on hamster PrP. As a result of the successful attachments, the force- extension curves of mouse prion proteins had close similarities in unfolding behavior compared to those of hamsters. Furthermore, according to the data analysis of the curves, the contour lengths of the mouse prion proteins from the combination of rips were found to be closely matched to the expected length in the protein structure. However, it was challenging to avoid problems caused by attaching the DNA handles to the wrong cysteine residues in the protein. For a more complete understanding of protein misfolding, future work involving the study of protein structure is required. Single-molecule studies of mouse prion proteins can also allow one to study the energy landscapes, specifically the folding pathways of proteins in different species. Information regarding protein structure may be useful for the development of specific therapeutic drugs. Future work on the molecular mechanisms of the prion proteins will not only provide a better understanding of prion diseases, but also other related neurodegenerative disease that share similar mechanisms of protein aggregation.
Author/Creators:
Charrunchon, Sookpichaya
Title:
Liquid Metal Based Test Structures and Reconfigurable Microfluidic Microwave Devices and Antennas
Description:
Electrically reconfiguring communicational devices suffer from a number of drawbacks: incorporating electrical elements such as varactors in unit cell level to manipulate the inductance/capacitance of the circuits and maintaining RF/DC interference isolation in power supply is very challenging. In this thesis, a mechanical tuning approach for communicational devices is proposed with stretching or curving these devices. Devices are fabricated based on the gecko-fluidic reversible bonding technique with EGaIn liquid metal (LM) as their conductor and a new thermoplastic substrate (SEBS) with a versatile and cost effective manufacturing method. Selective filling of complex micro-fluidic features is realized with the use of hydrophobic valves which are optimized based on the measured critical pressure of oxidized EGaIn for filling SEBS channels. Laplace barriers are used to achieve “auto-filling” of extremely low aspect ratio channels of LM in SEBS substrate. Furthermore, a technique for making multiple discrete units of LM features from a monolithic injected LM pattern. As a proof of concept, mechanically reconfigurable antennas such as a half-wavelength folded dipole, a multilayer dipole with a soft via, and a micro-strip patch are fabricated and measured for tuning in their center frequency. A super stretchable beam reconfigurable FSS is also manufactured which shifts its beam direction by stretching or curving.
Author/Creators:
Zandvakili, Mersedeh
Title:
Optimizing Oat Yield, Quality and Stand-ability in Central Alberta
Description:
The value of oat (Avena sativa L.) for the producer is a function of both grain yield and quality. Therefore, managing nitrogen fertilizer rates to optimize yield while meeting expected grain quality standards is essential in guaranteeing profitable production. To determine the effect of nitrogen fertilization on grain yield and quality, field studies were conducted at Barrhead and St. Albert, AB over a three-year period (2014–2016) to determine responses to four nitrogen fertilizer rates (5, 50, 100, 150 kg ha-1) on five oat cultivars differing widely in agronomic traits. Grain yield, grain quality and β-glucan content of oat were measured. Application of nitrogen fertilizer resulted in a significant increase in grain yield, plant height and lodging score. Grain quality such as test weight and plump kernel decreased with greater nitrogen fertilizer rates. Average β-glucan content differed between cultivars. Optimizing oat yield and quality for high-value markets may be achieved by selecting well adapted cultivars and N fertility rates. The use of the plant growth regulator (PGR) trinexapac-ethyl has been shown to reduce lodging in cereal crops. Plant growth regulators of interest in Canadian cereal cropping systems are intended to restrict plant height and thereby reduce lodging susceptibility. Experiments were conducted over a three-year period (2014–2016) to determine the effect of trinexapac-ethyl application and nitrogen fertilization on yield, lodging and related agronomic responses of oat. The experiment was arranged in a randomized complete block with four replicates. The treatments consisted of four trinexapac-ethyl application rates (0, 70, 100 and 130 g a.i ha-1) and four nitrogen rates (5, 50, 100 and 150 kg ha-1), on the cultivar Stride. Grain yield, plant height, lodging score and grain quality parameters were evaluated. Grain yield was unaffected by applications of trinexapac-ethyl. Plant height was reduced by 5% to 16% with increasing rates of trinexapac-ethyl. PGR application had a significant effect on lodging at two experimental sites, where the severity of lodging was reduced 12% to 31% with high rates PGR application. The rates of nitrogen influenced grain yield, height and lodging. Using PGRs to maintain grain yield and avert lodging are necessary only under conditions where lodging represents a substantial risk.
Author/Creators:
Aidoo, Joseph Paapa
Title:
Religious Debates Doth Not a Community Make - North American Muslim Counterpublics and the Limits of Community
Description:
In the face of a sustained political rhetoric that constitutes Islam as the proverbial ‘other,’ Muslim communities face external pressures of geopolitical proportions. Within these communities too, however, a vibrant and sometimes tense internal discourse has shaped the ways Muslims see authority, identity and belonging. This study seeks to elaborate structural tensions in North American Muslim communities and the frameworks informing the creative responses to them. It connects these tensions to a historical shift toward transnational pan- Islamic paradigms borrowed from twentieth-century Islamist movements. Informed by anticolonial discourses and methodological debates in the anthropology of Islam, this study argues against conflating the notions of ‘counterpublic’ and ‘community.’ Through a mixed media comparative case study of two North American Muslim organizations, Ta’leef Collective and the el-Tawhid Juma Circle/Unity Mosque, this thesis employs the model of religious economy to analytically map perceived tensions and their responses. The study concludes by developing a new conceptualization of Muslim community that distinguishes between intentional communities and de facto communities, demonstrating that a more localized vision of community might better address perceived tensions.
Author/Creators:
Maseehuddin, Farooq
Title:
Wolf Lake: The Importance of Métis Connection to Land and Place
Description:
This thesis provides an analysis of Métis territoriality by examining the importance of Métis connection to land and place. In utilizing written archival document, as well as unwritten such as maps and photographs, the research sheds light on the connection Métis people had with the displaced community of Wolf Lake, Alberta. In examining the displaced Métis community of Wolf Lake, which became a Métis settlement in the 1930s and was disbanded in 1960, the research reveals the layered connection to specific places. Wolf Lake was once a Métis wintering place, where families gathered to hunt and trap during the winter months. As settlement encroached upon Métis mobility, Wolf Lake became a more permanent year round community. It was a place where Métis families made a living with the land, which fostered their political, economic and social traditions. Such connections to land and place occurred through daily life activities, one based on reciprocity with all living and non-living relations. The colonial system disregarded the sophisticated way of knowing of Métis peoples and communities. Dispossession occurred at Wolf Lake due to colonial understanding of land as a ‘thing’. Therefore governments and settlers harnessed the area for its resources such as oil, gas, and timber, and for its military potential with the establishment of the Primrose Air Weapons Range in 1956. Government initiatives and systems functioned to disinherit Métis peoples from the land. The research renders these histories of forced displacement visible, in order to challenge narratives that erase Indigenous histories, and enables a platform by which Indigenous histories and relations to the land may be reframed. Wolf Lake serves as an important reminder of the existence of Métis territory, and the importance of Métis places
Author/Creators:
Roy Denis, Chantal A
Title:
International Non-Governmental Organizations and Human Rights-Based Approaches to Dam Development and Dispossession in Asia, Africa and the Americas: A Critical Case Study of International Rivers
Description:
International Rivers (IR), an International Non-Governmental Organization (INGO) based in Berkeley, California with six regional offices in Asia, Africa and the Americas has been at the forefront of the fight for rivers and dams for the past three decades. Conservative estimates place the number of people displaced by major dam projects at between 40 to 80 million people. Since the report of the World Commission on Dams in the early 2000s, International Rivers has promoted a human rights-based approach (HRBA) to development to address the impacts of dam projects for the people who call the rivers home; a politics with a questionable track record in preventing dispossession and market violence. Dam projects often proceed despite INGO initiated HRBA opposition in conjunction with the struggles or movements of affected people, or resume after what may have been an initially successful campaign to prevent their construction. Informed by a critical interpretive methodology, this instrumental case study is a critical exploration of how International Rivers utilizes HRBA to development including human rights education (HRE) in contexts of development dispossession by big dam projects in Asia, Africa and the Americas. Staff members of International Rivers based both in the United States and at one of their regional offices were interviewed, and secondary documentation and materials produced by IR were analyzed. Expert interviews were also conducted with individuals experienced with INGO politics pertaining to dam and other mega development project related dispossession in these regions to triangulate and generate critical data and analysis of HRBA and HRE in contexts of development dispossession. Relying primarily on select neo-Marxist concepts and analytical critiques of a human rights politics and the globalization of capitalism, the study demonstrates the contradictions and limits, if not the complicity, of HRBA to addressing dam related development dispossession in neocolonial regions by INGOs such as IR. The emergent critique has implications for how INGOs use these approaches, including HRE and praxis, in contexts of development dispossession in these regions, and contributes towards the growing body of empirical and critical analytical literature on human rights, human rights education, capital and development dispossession, especially by mega dam projects.
Author/Creators:
Fisher, Kyla L
Title:
Remembering the Departure of Moroccan Jews
Description:
Nakita S. Valerio, 2017 “Remembering the Departure of Moroccan Jews” Before the end of the Second World War, Morocco’s Jewish community numbered approximately 240,000 people and was one of the largest and oldest populations of Jews in the Arab-Muslim world. Between 1948 and 1968, the vast majority of the Jewish population left the country. As a narrative, the plotline of their departure seems straight-forward: a large group of people who came to see themselves as belonging to one another lived in Morocco and then, over a period of two decades, almost all of them left. It is the question of why they left which gives rise to a multiplicity of competing memories, expressed in three main theatres: the historiography, the testimonies of émigrés themselves, and popular performative media. The main question this thesis answers is how the causality of the departure of Moroccan Jews is remembered in these three domains, as well as how they reference and respond to one another, and why this is the case. This thesis shows that, across these domains, there are seven main narrative forms about the departure and that each of these forms is, most importantly, accompanied by a prelude and a post-script which inform the basic narrative of the cause of the departure in different ways. By examining who remembers what, according to the discursive, ideological environments in which these memories are formed, as well as what is diminished or silenced in each of these memories, this study contributes to a growing body of research on the effect of the contemporary moment on historical memory and popular commemoration.
Author/Creators:
Valerio, Nakita S.
Title:
Beyond the Book on the Shelf: The Value of Translation Theory
Description:
For many, translation begins and ends with the book on the shelf; it is often thought to be the end product of a simple process of linguistic transfer between languages, completed by someone who simply has knowledge of both languages. However, this hardly captures the nature of translation and is at best a poor understanding of the act and field of translation. Each act of translation involves a complex negotiation between languages and cultures. The intricacies and complexities of each act of translation, which is grounded in translation theory, are not widely known. This is quite unfortunate as there are benefits to becoming familiar with the translation theories that ground the work of translators. Comparing and analyzing three translations of Yoko Tawada’s “Das Fremde aus der Dose” I will demonstrate what we can learn about translation theory through the act of translation. I will explore the ways in which translation theory allows us to accommodate and appreciate the social nature of translation in useful and practical ways beyond the book on the shelf.
Author/Creators:
Lockhart, LoriAnn D
Title:
Remembering Solomon: Constructions of Solomon in Kings and Chronicles
Description:
Narratives of King Solomon’s life and reign are preserved in both the Book of Kings and the Book of Chronicles, and both texts contain similar narrative elements and mnemonic constructions, such as Solomon’s role as Temple builder and his great wisdom. Other elements of the narrative have been shortened, lengthened or even omitted between the texts. By using the lens of social memory to investigate the reshaping of the narrative of Solomon by the Chronicler, one can attempt to further understand the reasoning for both the changes and similarities between the two texts. Although the mnemonic constructions of Solomon in both Kings and Chronicles are rooted in matters of kingship and rule, the issues themselves are vastly different and representative of the concerns of their respective communities. In Kings, the narrative of Solomon’s rise and ultimate fall interacted with these larger mnemonic constructions to inform the reader about the fundamental issues with mortal kingship. In contrast, the narrative of Solomon in the Book of Chronicles instead focused its attention on the maintenance of cult, leading to memories of ancestral merit, legitimization and even utopia during a time of non- Davidic kingship.
Author/Creators:
Swann, Jessica J
Title:
Clinical and Angiographic Outcomes Associated with Surgical Revascularization of Angiographically Borderline 50-69% Coronary Artery Stenoses
Description:
Objectives: Coronary artery bypass grafting improves outcomes in patients with multi-vessel coronary artery disease. Bypass of angiographically significant lesions ≥70% is recommended, yet little is known about the incidence/outcomes with bypasses of 50-69% angiographically borderline lesions without fractional flow reserve testing. The objective of this study was to investigate the incidence and outcomes of bypass of 50-69% angiographically borderline lesions. Methods: Between 2007 and 2013, 3,195 patients underwent isolated first multi-vessel coronary artery bypass grafting at the Mazankowski Alberta Heart Institute. Patients with an isolated angiographically borderline lesion of a major epicardial vessel were included. The primary analysis compared clinical and angiographic outcomes between patients with and without coronary bypasses of angiographically borderline lesions. Outcomes of interest included time to all-cause mortality, 30 day, and 1 year mortality. Results: Among 350 patients with an angiographically borderline lesion, 268 (76.6%) had the vessel containing the angiographically borderline lesion bypassed while 82 (23.4%) did not. Mean follow-up was 4.2 years. Patients with a bypassed angiographically borderline lesion were older (66.1 vs 62.5 mean years, p=0.006) but otherwise similar in sex, comorbidities, diabetes, ejection fraction, and number of coronary stenoses. Cardiopulmonary bypass time was longer in patients with bypassed angiographically borderline lesions (104.2 versus 90.4 minutes, mean, p<0.001). Unadjusted overall mortality through end of follow-up was higher among patients with bypassed angiographically borderline lesions (11.6% versus 3.7%, p=0.034). After multi-variable adjustment, the association between angiographically borderline lesion bypass and mortality was attenuated (hazard ratio 2.84: 95% confidence interval, 0.87 – 9.23, p=0.080). No differences were observed in unadjusted 30-day (1.1% versus 0.0%, p=0.336) or 1-year mortality (4.1% versus 0.0%, p=0.062). Repeat revascularization of patients with bypassed angiographically borderline lesions was numerically higher (4.1% versus 0.0%, p = 0.107). Conclusions: In an unselected cohort of patients with angiographically borderline lesions, bypass of borderline 50-69% lesions is frequently performed and not associated with improved long-term survival. Our findings suggest that the routine surgical revascularization of 50-69% angiographically borderline lesions may not be warranted.
Author/Creators:
Senaratne, Janek M
Title:
Challenges and Opportunities of Rural Nursing Preceptorship: A Photovoice Perspective
Description:
In nursing education, preceptorship practica typically occur at the end of the undergraduate nursing program and are intended to consolidate learning as the student prepares to enter practice. Nursing students are evaluated throughout the preceptorship in part related to their ability to manage and evaluate their nursing care in terms of the entry to practice competencies. Preceptorship, being a high-stakes practice course is inherently challenging and stressful for nursing students. To date, there is a dearth of literature that has addressed the challenges and opportunities experienced by members of the preceptorship triad namely the nursing student, their faculty advisor and preceptor. The purpose of this study was to explore the challenges and opportunities associated with rural preceptorship by nursing students, their faculty advisors and preceptors. Gaps exist in the current literature concerning strategies to prepare nursing students for rural nursing preceptorship and practice. Photovoice was used as a creative approach to participatory action research (PAR), which has been found to empower and engage community members as co-researchers, for the purpose of implementing change based on the priorities of the community, in this case, teaching and learning experiences of nursing students and their faculty advisors. The study sample comprised nine senior nursing students, assigned to rural communities in a western Canadian province for their final clinical preceptorship, and five faculty advisors who moved between communities. Participants were provided with digital cameras and instructed to photograph the challenges and opportunities of rural nursing practice. The participants then selected their own photographs to present to the researcher, serving as an impetus for rich discussions during face-to-face, individual interviews. The findings from this research project offer new insights into the rural preceptorship experience, from the perspective of the students and faculty advisors. This study yields data germane to the rural setting, and relates a story of rural nursing preceptorship based on imagery and interviews. As participants described their experiences throughout the preceptorship placement, four overarching thematic clusters emerged: (1) sense of rurality, (2) rural versus urban placements, (3) travel, and (4) making do with limited resources. The implications of this study are relevant to the role of the nurse educator in the preparation of students for both the opportunities and challenges of rural nursing preceptorships. If students successfully navigate a positive preceptorship experience, this too may influence their desire to seek employment in a rural setting (Crow, Conger, & Knoki-Wilson, 2011; Edwards et al., 2004; Hunsberger et al., 2009; Killam & Carter, 2010; Webster, Lopez, Allnut, Clague, Jones & Bennett, 2010). Adequate preparation of future nurses, competent to practice in rural settings, is critical. This growing knowledge base requires comparative studies concerning challenges and opportunities in rural settings, during supervised clinical courses which could be further extended through comparative research in non-rural settings.
Author/Creators:
Oosterbroek, Tracy, A
Title:
Styles and Extended Techniques in 6 Works for Violin from Paraíba since 1952
Description:
The full thesis for this degree consists of three components: a recording of José Siqueira’s Sonata No. 02, José Alberto Kaplan’s Nordestinada, José Orlando Alves’s Sonatina for Violin and Piano and Introspecções, Ticiano Rocha’s Lágrimas de Oort for Violin Solo, and Marcílio Onofre’s Caminho Anacoluto II for Violin and Piano, scholarly notes to accompany this recording, and a final solo recital presenting these works. The recording was produced in June and July, 2017 at the University of Alberta’s Convocation Hall, while the recital was presented at the same venue on September 17, 2017 at 7:30 p.m. The scholarly notes seek to position the works by these Brazilian composers from the Brazilian state of Paraíba, spanning over 65 years, in an international level. The notes analyze the pieces individually and explore the technical challenges (including various extended techniques), folk tradition associations, and theoretical and compositional features of this music. Finally, this essay evaluates the significance of Paraíba’s composers within the landscape of Brazilian Northeastern violin music contributing to the violin literature as a whole. Supplemental material related to this thesis is available at https://era.library.ualberta.ca/collections/44558t441
Author/Creators:
Rufino, Vladimir M
Title:
COGNITIVE MARKERS OF ATTENTIONAL RESTORATION WHILE VIEWING NATURAL AND URBAN ENVIRONMENTS
Description:
Demands on directed attention can result in attentional fatigue, inhibiting our ability to voluntarily direct attention to important features of our surroundings. Inherently fascinating environments, such as nature, have been shown to promote recovery of attention. Environments that do not possess these restorative qualities, such as urban settings, by comparison do not promote recovery. Previous research has demonstrated numerous benefits associated with exposure to nature including improved physiological and mental health, and increased performance in attention tasks. Limited, if any, research has directly demonstrated the neurological correlates of recovery associated with nature. The goal of the current research was to utilise the P3 cognitive component of the event-related potential (ERP), which has been shown to be modulated by attentional demands, as a cognitive marker indicative of attentional recovery. We measured electroencephalography (EEG) data while participants simultaneously completed an auditory oddball task and viewed pictures containing nature and urban scenes. A replication was also performed using the Attention Network Task (ANT) to show that the restorative qualities of nature influence executive, voluntary attention rather than involuntary attention. Contrary to our predictions, no significant differences in the P3 component were observed and we were unable to successfully replicate previous research using the ANT. However, significant differences were found in earlier EEG components which suggest that the auditory stimuli are being processed differently depending on the scene displayed. EEG differences were also found following presentation of the scenes themselves. These differences are consistent with previous research and are likely due to differences in complexity, contrast, and other visual characteristics. Further research needs to focus on these auditory and visual EEG differences to better understand neural correlates associated with the restorative benefits of natural environments.
Author/Creators:
Kuziek, Jonathan WP
Title:
Host-adapted lactobacilli: evolution, molecular mechanisms and functional applications
Description:
Bacteria of the genus Lactobacillus can be found associated with plants, insects and vertebrate hosts, and their lifestyle can range from free-living to strictly host specific. Of the lactobacilli associated with vertebrates, the lifestyle of L. reuteri is particularly well understood. The species has been studied by population genetics, comparative genomic and functional analyses in animal models. The phylogenetic structure of L. reuteri suggests that lineages evolved alongside with rodents, poultry, swine and humans. For rodent strains, co-evolution resulted in host-adaptation. The first goal of this dissertation was to determine whether host-adaptation extended to non-rodent lineages and also to resolve open questions regarding the evolutionary relationships within lineage VI, which is shared by human and poultry isolates. An experimental approach was devised to determine the ability of strains to propagate under the ecological conditions of the gastrointestinal tract (GIT) of different hosts. Rodent isolates became enriched in the GIT of mice and poultry isolates in chickens. Moreover, human isolates of the lineage VI were found to be competitive in the GIT of chickens but not in humans. These findings revealed that L. reuteri evolved host-specialization in rodents and chicken, while open questions remain about the exact evolutionary consequences in humans and pigs. Biofilm formation is a common strategy by which lactobacilli maintain stable associations with their hosts. Only rodent isolates of L. reuteri can produce biofilms in the forestomach of mice. The second goal of this dissertation was to determine the role of a rodent-specific two component system (TCS70529-30) in biofilm formation of the rat isolate L. reuteri 100-23. Experiments in monoassociated mice revealed that mutation of the response regulator, but not the histidine kinase impaired biofilm formation. In vitro experiments confirmed in vivo and findings and further revealed significant alterations in the architecture of the mutant biofilms. Compared to the wildtype, histidine kinase mutants produced thick and robust biofilms, while the response regulator mutants formed thinner and less adherent biofilms. These findings provide empirical evidence of rodent specific signal transduction system playing a role in biofilm formation of L reuteri, likely by regulating genes responsible for development of the biofilm matrix. Contrary to rodent strains, human isolates of L. reuteri lack the genetic machinery to form biofilms, but conserve a 58-gene pdu-cbi-cob-hem cluster (pdu-cluster). Encoded in the pdu-cluster is the PduCDE diol dehydratase involved in utilization of 1,2 propanediol (1,2 PD). In the human gut, 1,2 PD is readily available as a result of fermentation of rhamnose and fucose found in dietary and host-derived glycans, respectively. The third goal of this dissertation was to determine the role of the pdu-cluster in utilization of 1,2 PD by human isolates of L. reuteri. The ability of the human isolate L. reuteri ATCC 6475 to cross-feed from 1,2 PD produced by Escherichia coli MG1655 and Bifidobacterium breve UCC2003 was determined in vitro and compared to a pduCDE mutant. We found that during fermentation of hexoses, 1,2 PD serves as an electron acceptor increasing the metabolic efficiency of L. reuteri, a factor that could be pivotal to the competitiveness of human isolates of the human GIT. The fourth goal of this dissertation was to identify and characterize bacterial isolates from the proximal GI tract of pigs capable of degrading peptides involved in the etiology of celiac disease. Strains were selected from the GIT tract of pigs fed a 20% gluten diet and after an in vitro process aimed to enrich for gluten degrading bacteria. Pigs were selected as these animals harbor large amounts of lactobacilli. Strains of the species L. amylovorus, L. johnsonii, L. ruminis, and L. salivarius were identified as having the highest proteolytic activity against several well characterized gluten immunotoxic peptides. Since these strains are adapted to the conditions in the proximal GI tract, they are likely to be good candidates for probiotics aimed at removing gluten epitopes before they reach the epithelium of the small intestine in celiac patients. Together findings in this dissertation contribute to our understanding of the evolution of L. reuteri with different vertebrate hosts, reveal insights into lineage-specific functions underlying adaptation to the vertebrate GIT, and provide a basis for the selection of lactobacilli adapted to GIT for functional applications.
Author/Creators:
Duar, Rebbeca M
Title:
Cardiovascular Effects of Aerobic Exercise Training in Hypoxic-induced Intrauterine Growth Restriction
Description:
Fetal hypoxia is one of the most common consequences of complicated pregnancies worldwide. It has been demonstrated that prenatal hypoxia leads to intrauterine growth restriction (IUGR). Being born growth restricted is associated with a decrease in cardiomyocyte proliferation, an increased susceptibility to cardiac ischemia/reperfusion (I/R) injury and impaired endothelial-dependent vascular function later in life, demonstrating that fetal environment during early development is important for cardiovascular health. Both I/R injury and endothelial dysfunction in hypoxic-induced IUGR offspring have been associated with an increase in the production of reactive oxygen species. Moreover, TNF-related weak inducer of apoptosis (TWEAK) induces cardiomyocyte proliferation through activation of the fibroblast growth factor-inducible molecule 14 (Fn-14) receptor. The TWEAK/Fn-14 pathway has not being studied in hypoxia-induced IUGR offspring. Early interventions are needed to ultimately reduce later life risk for cardiovascular disease. We tested whether aerobic exercise prevents the development of cardiovascular diseases in hypoxic-induced IUGR offspring. In addition, we tested whether the TWEAK/Fn-14 pathway play a role in cardiomyocyte proliferation, and this is associated with an increase susceptibility to cardiac I/R injury. Pregnant Sprague Dawley rats were exposed to control (21% oxygen) or hypoxia (11% oxygen) conditions from gestational day 15 to 21. Male and female offspring from normoxic (control) and hypoxic (IUGR) pregnancies were randomized at 10 weeks of age to either an exercise-trained or sedentary group. After acclimatization, rats ran on a treadmill for 6 weeks; 5 days/week, 30 min/day at 20 m/min. Twenty-four hours after the last bout of exercise, animals were euthanized and concentration response curves to phenylephrine and methylcholine were performed in second order mesenteric and gastrocnemius muscle arteries, in the presence or absence of L-NAME (100 µM), MnTBAP (10 µM), apamin (0.1 µM) and TRAM-34 (10 µM), or indomethacin (5 µM). On the same experimental day, ex vivo cardiac function was determined using a working heart preparation. Hearts were perfused for 10 min in retrograde Langendorff mode, and then switched to working heart mode. Global, normothermic flow ischemia was induced for 10 min. Following ischemia, hearts were reperfused for 40 min. Superoxide production in cardiac tissue was assessed. In a second set of experiments, ventricular cardiomyocytes were isolated at postnatal day one. Proliferation and protein expression of Fn-14 were determined. Cardiomyocyte proliferation was also assessed in the presence or absence of TWEAK. Aerobic exercise training improved endothelium-derived hyperpolarization-mediated vasodilation only in IUGR male offspring. Moreover, aerobic exercise training improved baseline cardiac performance and decreased superoxide generation in male control offspring while in hypoxic-induced IUGR offspring the opposite effect was observed. There was no effect of IUGR or exercise on cardiac or vascular function in female offspring. Being born growth restricted was not associated with differences in the Fn-14 protein expression or cardiomyocyte proliferation. After being in culture for 72-hours, cardiomyocytes from IUGR male offspring had a decreased proliferation compared to controls. Our findings demonstrated that in IUGR populations, a common preventive strategy such as aerobic exercise may represent a secondary stressor to the cardiovascular physiology. The results from the present study also highlight that when examining the mechanisms by which exercise impacts the cardiovascular system in a susceptible population, sexual dimorphism must be considered.
Author/Creators:
Reyes Martinez, Laura M
Title:
Gift Giving with Coercion in Rural Communities of Tanzania
Description:
Poor households may face various risks, especially in countries with limited access to public safety nets. In order to cope with these risks, poor households can implement ex ante risk-reducing strategies or rely on risk-coping system such as inter-household transfers. These transfers, which are mostly in kind, are often requested by the household in need and, as such, some amount of haggling and moral coercion take place in these demands. From the perspective of the receiver, exerting coercion to obtain more gifts when he is in real need, may be a way to help him to cope with risks and raise his welfare. To have a better understand of gifting behaviors among households, and especially how coercive effort from receiver influences gift values and well-being, this study uses a primary rich dataset collected from two Districts of Tanzania to examine the impact of altruism, coercion, gifting motivations, and demographic factors on gift values, and investigate the impact of gifting transfers on households' well-being. To do so, we first develop a gifting model where gift value is due to the combined effect of altruism and coercion. Consistent with our theoretical model, empirical results show that the gift monetary value is positively related to altruism, and that receivers extract more expensive gifts when they exert coercion on their close family members. Moreover, gift motivations and household demographic characteristics have various significant impacts on gift values. The model contributes to our understanding of mutual-help systems, and how coercion helps individuals to obtain gifts. Thoroughly examining what empirically determines the gifting value sheds light on existing mechanisms of insurance and emphasizes the hidden influence of social networks. We then use propensity score matching approach to explore the effect of gifting on the well-being of households. We find household that headed by male and elderly are less likely to be involved in gifting. And being involved in gifting indeed helps households to improve their consumption and production levels. These findings provide important policy implications to local government and NGOs.
Author/Creators:
Yang, Meng
Title:
Trade Size and the Changing Nature of Price Formation
Description:
Trading patterns in US financial markets have undergone significant changes in the past two decades. Using a 21-year (1993-2013) sample of intraday data, this thesis documents the ways in which the size distribution of trades—that is, the distribution of trades based on their dollar value—has changed over this period and examines changes in the price impact of trades and activities of informed traders. Chapter 1 examines changes in trading activity and quantifies changes in the size distribution of trades between 1993 and 2013. On average, the daily trading volume per stock increased from about $2 m to $25 m, whereas the average dollar amount per trade decreased from over $40,000 to about $5,000 over the same period. In 1993, 75% of the trading volume came from large trades (in excess of $50,000 in value), but small trades (less than $5,000 in value) accounted for more than 40% of the volume in 2013. The findings reported in Chapter 1 suggest the need for a study, presented in Chapter 2, which focuses on price formation over the sample period, contrasting the permanent and transitory price effects of trades conditional on their sizes. Changes in the price impact of trades are negatively related to trade size, with small trades exerting the largest price impact in recent years. Earlier studies such as that of Barclay and Warner (1993) showed that most “stealth” trading, i.e., strategic information-based trading, occurred in medium-sized trades. My results are consistent with those studies only in the early years of my sample period; they suggest that stealth trading now occurs in small trades. Further, the positive “price-quantity” relation predicted in Easley and O’Hara (1987) has seemingly vanished or even reversed in recent data. The close association between the shift in trade size distribution and transition of permanent price impact, as demonstrated by results presented in Chapters 1 and 2, indicates that informed traders are directly involved in those change patterns. Chapter 3 analyzes in more detail the behavior of informed traders during my sample period, assessing their role in driving the findings reported in Chapters 1 and 2. I expect to find that the increase in small trading volume is associated with a decrease in medium trading volume in particular, since studies such as that of Barclay and Warner show that stealth traders tend to concentrate on medium-sized trades. The results of my test point in the direction of this conjecture. I also test whether a temporary increase in information-based trading shifts the distribution of trades toward smaller transactions. I classify stocks according to their probability of information-based trading (PIN) values during each quarter, and I find that stocks with high PIN values tend more often to be traded in small sizes. The findings reported in Chapter 3 suggest that informed traders are actively involved in the migration of trade volume toward smaller trade sizes.
Author/Creators:
Al-Haji, Ahmad
Title:
A Constructivist Grounded Theory Study of Refugee Pathways In and Out of Homelessness
Description:
The current global humanitarian crisis has led to the record number of 65 million people being displaced from their homelands (United Nations High Commissioner for Refugees, 2017). Canada is one of the top refugee receiving countries in the world, receiving between 20,000 and 40,000 refugees annually (Government of Canada, 2016). Unfortunately, even after immigration, refugees tend to be more vulnerable to homelessness than all other immigrants and the general population in Canada (Murdie, 2008; Preston et al., 2011). The issue of refugee homelessness remains largely neglected in the research literature, with the extent of the problem, pathways into and out of homelessness and the unique service needs of this population remaining poorly understood (DeCandia, Murphy, & Coupe, 2014). This qualitative study utilized a constructivist grounded theory design to investigate the housing trajectories of adult refugees in Edmonton who had experienced homelessness after their arrival in Canada, and who made progress in exiting the cycle of homelessness by obtaining suitable and secure housing. Nineteen refugee participants from diverse countries including Afghanistan, Iraq, Ethiopia, Sudan, Somalia, Congo, Rwanda, and Syria participated in semi-structured interviews about their experiences, and their interview disclosures were triangulated with feedback from 10 service providers who had experience assisting refugees with the housing and settlement process. The emerging model of refugee homelessness identified 6 unique pathways into homelessness, and 7 unique pathways out of homelessness that are specific to refugees. Each of these pathways and the implications for policy and practice are discussed in this dissertation.
Author/Creators:
St Arnault, David
Title:
Prediction and Evaluation of Annular Pressure in Horizontal Directional Drilling
Description:
Horizontal directional drilling (HDD) is a crossing technique for the oil and gas, utilities, and infrastructure sectors for pipeline installations in different situations under natural or manmade obstacles. Annular pressure (plan pressure) and maximum allowable pressure predictions are critical issues for annular pressure management. During HDD operation, annular pressure must not exceed the maximum allowable pressure to minimize the risk of hydraulic fracturing, which leads to loss of drilling fluid and increase in overall project risk. This study aims to identify the shortcomings of common industrial methods in current HDD practices due to poor annular pressure management. Furthermore, this study intends to propose a scheme for better annular pressure management. To achieve this objective, the plan pressure and maximum allowable pressure during HDD operations must be estimated; however, the methods presently utilized by industry are not accurate. In the case of plan pressure estimation, the Bingham plastic model is commonly used in HDD operations to estimate the annular pressure. However, the Bingham plastic model overestimates the annular pressure, leading to incorrect bore path design and erroneous information from down-hole conditions. In the case of estimating the maximum allowable pressure of the drilling fluid, the Delft’s cavity expansion method is commonly used. The Delft’s method significantly overestimates the maximum allowable pressure of the drilling fluid due to its simplified assumptions and can lead to hydraulic fracture of the ground during HDD operations. This study introduces two methods extracted from the American Petroleum Institute (API) to estimate the plan pressure according to the power-law and Bingham plastic models, which are adjusted and modified for HDD operation during pilot boring. Prior to calculating the annular pressure, it is assumed that the borehole is under an ideal condition in which the borehole radius is not changed and the pressure loss and infiltration of drilling fluid are negligible. To understand the infiltration of drilling fluid into the adjacent soil, a series of experimental tests on the sandy soil have been conducted to show the formation of cake around the wellbore during HDD operation. The formation of the cake in high permeable soils such as sand prevents drilling fluid from infiltrating into the ground; however, the infiltration of the drilling fluid into the low permeable soil (e.g., clay) is negligible. To estimate the maximum allowable pressure of the drilling fluid during HDD operation in non-cohesive soil, a new approach has been introduced to overcome the improper estimations based on Delft’s method. This study has attempted to illustrate the lack of correlation between the allowable plastic radius and the failure pressure. This correlation has been applied in industry to the Delft’s cavity expansion method and Yu and Houlsby’s (1991) large strain cavity expansion method and has resulted in an overestimation of the failure pressure. The new approach is formulated based on the calculation of limit pressure using Yu and Houlsby’s (1991) large-strain cavity expansion method. The suggested limit pressure approach has been advanced further to obtain a practical and useful solution to estimate the failure pressure in different geotechnical conditions by providing a coefficient of limit pressure following the Yu and Houlsby’s (1991) method. To achieve this objective, the commercial finite element program ABAQUS has been used to estimate the failure pressure based on the limit pressure approach and correlates it with Yu and Houlsbly’s (1991) failure pressure. The coefficient of limit pressure is determined as a function of model and soil parameters (overburden depth, friction angle, and elastic modulus), and the significance of these parameters have been identified based on a parametric study. In the current study, several graphs have been generated to calculate the coefficient of limit pressure to estimate the failure pressure properly. The new approach on annular pressure management enables engineers to better predict and monitor the annular pressure in the borehole during the HDD operation. This allows engineers to diagnose and prevent any upcoming issues during drilling and estimate the maximum allowable pressure of the drilling fluid to mitigate the risks associated with high annular pressure in the borehole during HDD operation.
Author/Creators:
Rostami, Ali
Title:
The Herpes Simplex Virus 1 Transcription Activator ICP4 Modulates Histone Dynamics
Description:
Herpes simplex virus 1 (HSV-1) is a nuclear-replicating, double-stranded (ds) DNA virus. HSV-1 genes are expressed in a coordinate manner. The tegument protein VP16 first activates expression of the five immediate-early (IE) genes. Two IE proteins, ICP4 and ICP0, then activate early (E) and late (L) gene expression. The mechanisms whereby VP16 activate IE gene expression are so well characterized that VP16 is used as a tool to study gene expression in general. In contrast, the mechanisms whereby ICP4 and ICP0 activate gene expression are not fully understood. ICP4 is the only essential HSV-1 transcription activator. HSV-1 genomes are not chromatinized in the virion, but are chromatinized in the nucleus. The basic unit of chromatin is the nucleosome, composed of two each of the core histone dimers H2A-H2B and H3-H4 wrapped by 146 base pairs of dsDNA. Chromatin is dynamic, as histones disassemble from nucleosomes, diffuse through the free pool bound by chaperones, and reassemble nucleosomes at different sites. HSV-1 chromatin is more dynamic than cellular chromatin. Cellular chromatin dynamics are altered by the incorporation of variant histones in place of canonical ones. Variant H3.3 is enriched in nucleosomes assembled with DNA of transcribed genes or telomeres, and nucleosomes containing H3.3 are more dynamic than those assembled with H3.1. Variants macroH2A and H2A.B are preferentially enriched in nucleosomes assembled with DNA of silenced or transcribed genes, respectively. MacroH2A assembles less dynamic nucleosomes than canonical H2A, whereas H2A.B assembles more dynamic ones. Upon nuclear entry of HSV-1 genomes, the total amount of nuclear DNA increases and histone synthesis is inhibited. As the number of histone binding sites increases but the amount of histones does not, we would expect the histone free pools to decrease in HSV-1-infected cells. However, it increased. Nuclear entry of HSV-1 genomes is required to enhance histone free pools, but HSV-1 DNA replication is not. We proposed a model in which a cellular defense mechanism chromatinizes HSV-1 genomes to silence HSV-1 gene expression. To counteract silencing, HSV-1 evolved proteins that prevent or disrupt the stable chromatinization of their genomes. My hypothesis is that these proteins are HSV-1 transcription activators. In this thesis, I show that HSV-1 VP16 and ICP0 mutants still enhanced histone dynamics, though less so than the wild type virus, whereas ICP4 mutants barely enhanced them. To test whether ICP4 enhanced histone dynamics directly, I evaluated histone dynamics in cells co-expressing fluorescently tagged histones and full length or truncated, transcriptionally inactive, ICP4. The dynamics of H2B and H4, which have no variants and thus represent the H2A-H2B and H3-H4 dimers, were enhanced in cells expressing detectable levels of full length, but not truncated, ICP4. The dynamics of H3.1 and H3.3, which assemble less or more dynamic nucleosomes, respectively, were both enhanced in ICP4-expressing cells. Whereas H3.1 had granular distribution in cells expressing undetectable levels of ICP4, consistent with the incorporation of H3.1 in chromatin, it was diffusely distributed in ICP4-expressing cells. H3.3 distribution was not affected by ICP4. The dynamics of H2A, macroH2A, H2A.X, or H2A.Z did not change in ICP4-expressing cells, but those of H2A.B were enhanced. The distribution of H2A.B was altered in ICP4-expressing cells, with greater H2A.B enrichment at the nucleolus, where ICP4 itself localized. Histones in the nucleolus are more dynamic than those in the cellular chromatin. The increased dynamics of H2A.B in ICP4-expressing cells may thus be a result of the greater amount of H2A.B in the most dynamic population. The nucleolus is disassembled in HSV-1-infected cells. Whereas H2A, macroH2A, and H2A.X are mostly depleted from the replication compartments, H2A.B was less so. The dynamics of all H2A variants except for H2A.B increased in HSV-1-infected cells. In cells infected with an HSV-1 mutant encoding truncated ICP4, n12, the replication compartments do not form and the nucleoli are fragmented. H2A.B is displaced from the fragmented nucleoli in n12-infected cells, but its dynamics do not decrease. Functional ICP4 is thus not required to displace H2A.B from the nucleolus, but is required to decrease H2A.B dynamics. In this thesis, I show that ICP4 is the major HSV-1 modulator of histone dynamics. I suggest a model in which ICP4 activates transcription by maintaining the HSV-1 genomes in a most dynamically chromatinized and transcriptionally competent state.
Author/Creators:
Gibeault, Rebecca L
Title:
Pride Politics: A Socio-Affective Analysis
Description:
This dissertation explores the affective politics of pride in the context of neoliberalism and the multitude of way that proud feelings map onto issues of social justice. Since pride is so varied in both its individual and political manifestations, I draw on numerous instances of collective pride to attend to the relational, structural and historical contours of proud feelings. Given the methodological challenges posed by affect, I use a mixed-method approach that includes interviews, participant observation, and discourse analysis, while being keenly attuned to the tension between bodily materiality and discursivity. Each chapter attends to an “event” of pride, exploring its emergence during particular encounters with collective difference. The project fills a gap in affect theory by attending to the way that proud feelings play a vital role in both igniting the political intensity necessary to bring about change (through Pride politics), and blocking or extinguishing possibilities of respectful dialogue and solidarity across gendered, sexual, and racial difference. Across the chapters, pride is used as a conduit through which the complexity of affective politics can be examined. The proud events around and through which each chapter is structured expose paths of affect and its politics. Taken together, the chapters provide an initial blueprint for navigating contemporary affective politics. Through an examination of the discursive rendering of pride, I find that, across several literatures, two key characteristics of pride are its deep relationality between individuals and collectives, and the way it circulates, is managed, and emerges in relation to social hierarches and the value attached to political categories (race, class, gender, ability). Because of the dynamic variability of pride as it moves across and through individuals, collectives, political categories and signs, I develop four analytical modes—normative pride, pride from below, wounded pride, and neoliberal pride—through which pride circulates and can be expressed. The modes are explored throughout the chapters, specifically the relationship between pride from below and neoliberal pride in the context of Gay Pride and Black Pride politics. I argue that, at the level of the individual, pride from below is a mechanism by which pain in the body that results from the tension between lived experience and dominant discursive realities can be expelled from the body. However, in that individual experience can be isolating and often disconnected from structural realities, I argue that activist and political writing are crucial (events) to the process of suturing the individual to the collective through the use of the language of pride as a galvanizing political force. Critical to my argument is the acknowledgment that pride is one way to name or articulate the wildness of individual and collective affect. The process of translating affect into language, most often emotions such as pride, is tenuous, ambivalent, and always-already incomplete. I explore the ambivalence of collective feeling through an examination of Gay Pride events, particularly the tension between pride from below and neoliberal pride, and suggest that a) collective pride is simultaneously enhancing and diminishing to bodies, and that b) the inherent wildness of affect forecloses possibilities of completely governing collective feeling, such as pride. Given the dynamism and unpredictability of affect, I suggest that attention to strategy in the realm of affective politics is of utmost importance. I read the event of Beyoncé’s Superbowl 2016 performance through the lens of affective political strategy, arguing that such a reading demonstrates the importance of timing and dosage to maximize affective and political impact. Key to Beyoncé’s success, I argue, is her movement through and simultaneous expressions of pride from below and neoliberal pride. Lastly, by staging an encounter between pride and laughter in a particular space—a safe house for inner-city street level sex workers—I show how affective-political encounters are simultaneously individual, collective, and structural. I offer a vision of what pride and its politics can look like when detached from a stable identity category and attached instead to a politics sensitive to the immanence of encounters. This ethico-political sensitivity is the basis upon which a model of assessing claims at the level of affective transmission can be offered, as I do in the conclusion.
Author/Creators:
Nixon, Randi
Title:
Treatment of Adolescent Alcohol Misuse and Clinician Acceptance of Technology-facilitated Care in the Emergency Department
Description:
Screening, brief intervention, and referral to treatment (SBIRT) is the recommended approach for clinicians to use with adolescent patients with suspected alcohol-related problems. Although the emergency department (ED) is an opportune setting for early identification of alcohol misuse, SBIRT is underused. Use of technology to facilitate the delivery of SBIRT is regarded as a promising strategy to standardize, expedite, and support delivery of care. However, little is known about its implementation in real-world clinical practice. The aim of this research was to explore the acceptance of technology-facilitated care in the ED, particularly, for the treatment of adolescent patients with problematic alcohol use. This thesis includes a scoping review (Study 1) and survey (Study 2). Study 1 was guided by the Arksey and O’Malley scoping review framework and examined emergency clinicians’ acceptance of cognitive support technology used at the point-of-care (POC) in the ED. This review demonstrated that while health care providers are receptive to technology-facilitated care in the ED, gaps remain between provider intentions and practice. Study 2 was a cross-sectional survey of pediatric emergency physicians from across Canada. A 35-item questionnaire was developed to examine physicians’ perceptions of adolescent alcohol drinking and treatment for alcohol misuse, current SBIRT practices, and acceptance of technology-based SBIRT. Survey findings revealed that physicians recognize the need and responsibility to address adolescent alcohol misuse. However, confidence in knowledge and abilities for SBIRT execution was low. While physicians were receptive to using technology to deliver SBIRT, they were unsure about its impact on patient care. Taken together, findings from both studies suggest that to promote integrated technology-facilitated patient care, strategies to support and orient clinicians when using technology are needed.
Author/Creators:
Jun, Shelly U
Title:
SOLID STATE NANOPORE : SIMULATION, CHARACTERIZATION AND MOLECULAR SENSING
Description:
Single molecule passing through a nanopore is a process that is important in science. Some molecules develop a surface charge when diffused into a salt solution, when these molecules pass through the nanopore, they reduce or increase the ionic current. The drop or rise in the current level is dependent on the size and shape of the molecule, and consequently differs for each molecule. Hybrid nanopores, a sensing device which integrates biological and synthetic nanopores is a powerful tool for nanopore-based sensing. A detailed characterization of the synthetic or solid state nanopores is required to integrate it with biological nanopores. In this thesis a detailed characterization of solid state nanopores is performed by comparing experimental and simulated conductance models. Solid state nanopores fabricated using Transmission Electron Microscope, ranging in size from 4 to 10 nm were measured for conductance, using Axopatch 200B. Cleanroom-based cleaning and mounting of the nanopore (and related accessories) was utilized to improve the yield of functional nanopores, prior to conductance measurements. The experimentally measured conductance was then matched with conductance obtained from finite element modeling (using COMSOL Multiphysics platform) of the electrokinetic processes occurring in a nanopore. Poisson-Nernst-Planck system coupled with Navier stokes equations was used for this purpose. The experimental and simulated conductance results of various solid state nanopores matched within an error range of 10 - 25 %. Upon validation of the COMSOL model, the model was used for analyzing various parametric effects on conductance. Conductance dependence on pore shape and size was analyzed in detail. The simulation technique can be used to predict the required size and shape of a solid state pore for desired conductance. Effect of pore size, shape, thickness and the membrane surface charge on nanopore conductance has been discussed. Nanopore sensing has been explored, by testing translocation of different molecules, namely, DNA, polysaccharides and proteins. Size and conformation prediction of DNA, polysaccharide molecules as they translocate through nanopores has been demonstrated. An attempt to create a hybrid nanopore, by inserting protein pore (OmpG) onto a solid state nanopore was conducted. Protein pore(s) insertion onto the solid state nanopore with and without guiding DNA molecule was observed. Subsequently, protein partial closing and opening has also been observed, hinting at the capability of nanopore sensors to act as powerful tools in selective sensing. In summary, this thesis demonstrates the ability of simulation technique to predict the conductance of a solid state nanopore under different chemical, physical and surface property conditions of the pore. These results could be further used to fine tune the fabrication of solid state nanopores to better understand and facilitate formation of hybrid nanopores elegantly.
Author/Creators:
Rengarajan, Uppiliappan
Title:
Impact of carcass chill time on the microbiology of horse meat
Description:
Globally, Canada is the third largest producer of horse meat, having an annual production of approximately 700,000 tonnes. Canadian regulatory standards require carcasses harvested for meat to have the warmest part of the carcass cooled to 7°C before meat can be harvested. Other processes can be approved if scientific evidence of the safety of the meat is provided. This research evaluated the microbiological condition of horse meat harvested at an internal temperature of 13°C. Temperature profiles of horse carcasses were created to determine the chill times required to reach internal temperatures of 13°C, 8°C and <7°C, with 17, 26, and 30 h, respectively, to be optimal chill times for operational purposes in the facility. The process hygiene of the abattoir was comparable to what is found in federally regulated beef plants with counts of 3.25 log CFU/1000 cm2 total aerobic bacteria and 0.54 log CFU/1000 cm2 Enterobacteriaceae. Semimembranosus muscles harvested from horse carcasses after 17 (13°C), 26 (8°C) or 30 h (<7°C) of chilling at 2°C had no significant difference in bacteria counts among chill times with approximately 4.5 log CFU/1000 cm2 of total aerobic bacteria, 2.2 log CFU/1000 cm2 of lactic acid bacteria, and Enterobacteriaceae were below the detection limit. Chill time had no effect on the total aerobic bacteria or lactic acid bacteria during the first 60 d of storage; however, after 90 d of storage, steaks from semimembranosus muscles harvested after 17 h of chilling had lower bacteria counts than those harvested at 30 h. Enterobacteriaceae counts on steaks were below the detection limit on most steaks. Metagenomic analysis of the microbial DNA from steaks stored for 90 d revealed an abundance of Pseudomonas and Serratia. Analysis of culturable bacteria from plate count agar similarly determined that Pseudomonas and Serratia were present in high abundance, whereas the culturable microbiota obtained from the all-purpose tween agar had a high abundance of Enterobacteriaceae. All data support the hypothesis that horse meat can be harvested at 13°C with no negative microbiological hygiene or safety issues when compared to horse meat harvested at <7°C.
Author/Creators:
Walker, Brian D
Title:
Preliminary validation of a computer-based approach to find new lead molecules targeting the oncogenic Forkhead box M1 transcription factor
Description:
The upregulation of the forkhead box M1 (FOXM1) transcription factor is directly correlated with cancer initiation, invasion, and drug resistance. Because the overexpression of FOXM1 is considered an important factor in carcinogenesis, this protein could be a relevant drug target in cancer treatment, and possibly, in cancer imaging. Literature reports describe the use of (a) siRNA, (b) proteasome inhibitors (which upregulate the expression of an endogenous negative regulator of FOXM1), and (c) other small-molecule drugs targeting FOXM1, as the three main strategies employed to decrease the transcriptional activity of FOXM1 in vivo and in vitro. Nevertheless, the first two approaches are either inconvenient because of the poor stability and the inefficient oligonucleotide intracellular delivery system (siRNA), or they potentially would exert significant side effects (proteasome inhibition). For this reason, developing new small-molecule drugs, that directly target the FOXM1 protein, represents an interesting and promising research opportunity in Medicinal Chemistry. As a part of a long-term multidisciplinary research project aimed to validate the FOXM1 protein as a drug target, we recently conducted a molecular modeling (docking) approach in which we determined the theoretical binding energies of 3,323 drugs that are (or were) approved by FDA, using the reported FOXM1-DNA binding domain. The aim of this research work was to validate a computer-based (in silico) approach by correlating the calculated binding energies of hit molecules, with their ability to interfere with the transcriptional activity of FOXM1 in vitro using breast cancer (MDA-MB-231 and MCF-7) and non-cancer (MCF-10A) cells, screening for potency and selectivity, respectively. In this regard, we carried out (A) MTT colorimetric and (B) western blot assays to evaluate the effect exerted by selected drugs (troglitazone, β-estradiol-3-benzoate gliquidone, dehydrocholic acid and metocurine, using thiostrepton as a positive control) on cell viability and protein expression. To determine the ability of the test drugs to block the binding interaction between FOXM1 and DNA, we used the electrophoretic mobility shift assay (EMSA). The MTT assay results illustrated that troglitazone, β-estradiol-3-benzoate and the control drug thiostrepton are cytostatic to MDA-MB-231 cancer cells but they are not selective as they also inhibited the proliferation of normal MCF-10A cells. However, these drugs did not inhibit MCF-7 cells proliferation. Western blotting assay results showed that troglitazone significantly inhibited FOXM1 protein expression at a concentration lower than its IC50 value, suggesting that troglitazone cytostatic effect is FOXM1-dependent. Rather than decreasing FOXM1 expression, β-estradiol-3-benzoate increased protein expression as it might act by FOXM1-independent pathways. In addition, it is a hormone-like drug and is likely to be an unsuitable scaffold to design new FOXM1 inhibitors. Gliquidone gradually inhibited FOXM1 protein expression, but this inhibitory effect did not correlate with its effects on cell viability (MDA-MB-231 cancer cells). Finally, dehydrocholic acid and metocurine did not show any effect on cell viability or protein expression, which rules them out as scaffolds to design new FOXM1 inhibitors. Regarding the EMSA assay, we could not modify this assay to work with our recombinant FOXM1 DBD-DNA complex; accordingly, we could not validate the in-silico model to determine the mechanism of drugs on cell proliferation and protein expression. In summary, we identified the drug troglitazone as the most promising lead molecule to be used in future drug design programs. On this regard, our group is currently developing troglitazone-based FOXM1 inhibitors capable of exerting binding interactions via a π-sulfur interaction involving troglitazone’s thiazolidinedione ring and a His287 residue, within the FOXM1 – DNA binding pocket. This binding interaction seems to be the main driving force guiding the inhibitory effects of several types of FOXM1 inhibitors, and it constitutes a novel mechanism of action for future FOXM1 inhibitors.
Author/Creators:
Elshaikh, Asya S Egweda
Title:
Drug Exposure Definition and Healthy User Bias Impacts on the Evaluation of Oral Anti Hyperglycemic Therapies
Description:
Accurate estimation of medication use is an essential component of any pharmacoepidemiological research as exposure misclassification will threaten study validity and lead to spurious associations. Many pharmacoepidemiological studies use simple definitions, such as the categorical “any versus no use” to classify oral antihyperglycemic medications exposure, which has potentially serious drawbacks. This approach has led to numerous highly publicized observational studies of metformin effect on health outcomes reporting exaggerated relationships that were later contradicted by randomized controlled trials. Although selection bias, unmeasured confounding, and many other factors contribute to the discrepancies, one critical element, which is often overlooked, is the method used to define exposure. Another factor that may provide additional explanation for the discrepancy between randomized controlled trials and observational study results of the association between metformin use and various health outcomes is the healthy user effect. Aspects of a healthy lifestyle such as following a balanced diet, exercising regularly, avoiding tobacco use, etc., are not recorded in typical administrative databases and failure to account for these factors in observational studies may introduce bias and produce spurious associations. The influence of a healthy user bias has not been fully examined when evaluating the effect of oral antihyperglycemic therapies in observational studies. It is possible that some, if not all, of the benefit, observed with metformin in observational studies may be related to analytic design and exposure definitions. Thus, our first objective is to explore the potential impact of exposure definition on estimates of the association between metformin and all-cause mortality risk, using a large administrative health database, similar to databases used in previous studies. The variety of exposure definitions tested in our analysis produced a wide range of associations between metformin and mortality risk, therefore, we recommend that pharmacoepidemiological studies should include at least two exposure definitions and sensitivity analyses of different exposure definitions. Moreover, our second objective is to explore the healthy user effect in metformin users versus non-users on various health outcomes that should not be associated with metformin use. Results of this study suggest that metformin users are more likely to initiate preventive therapies and engage in other healthy behaviors, therefore we recommend that the influence of these behaviors should be accounted for pharmacoepidemiological studies evaluating the effect of oral antihyperglycemic therapies.
Author/Creators:
Eskin, Maxim
Title:
Flocculation-assisted dewatering of fluid fine tailings using a volute screw press
Description:
Rapid, efficient and economical water removal from fluid fine tailings represents a major challenge to many industries, including mineral processing, food processing, waste water treatment and oil sands extraction. In the absence of large-scale fine tailings processing facilities, there will be an escalating accumulation of such waste material in containment areas, which requires careful, extensive and often costly measures for hazards mitigation. A flocculation-assisted two-stage process to continuously dewater oil sands fluid fine tailings using a volute screw press is developed. A cationic-anionic flocculant scheme was applied first to the fluid fine tailings, which flocculated essentially all suspended solids in the slurry. The concept of elastic and plastic deformations for metallic solids was extended and successfully applied to describe compression and subsequent water release characteristics of semi-solid tailings sediment. The newly developed “controlled vertical strain test” (CVST) enables bench-scale measurement on the theorized impact of flocculants on sediment compressive dewaterability. A new empirical parameter named “compressive dewatering index” (CDI) was obtained from the sediment compression response curve via the CVST method. The flocculated slurry was introduced to the volute screw press through a series of inclined steel rings (volute plates), and carried upwards by a central auger screw. Unobstructed and self-cleaning spacing between all volute plates ensures removal of unhindered supernatant, while large flocs of sufficient mechanical strength were retained and compressed by the screw. Field test work at Canadian Natural Resources Limited with a prototype volute screw press demonstrated successful production of stackable cake containing 55 - 60 wt% solids at 5 - 7 kg dry solids/h production rate. The field test results showed a strong linear correlation between the CDI and the filter cake dry solids content produced by the volute screw press. Such correlation allows predictive evaluations on the volute screw press dewatering performance at bench-scale. For elastic sediments, the slope of this linear correlation is termed as the CDI gain of the fluid fine slurry. This intrinsic and material-specific parameter could be used to universally classify any given fine fluid mineral slurry in its dewatering difficulty by mechanical means. The findings from this study could serve as a unified theoretical framework for future research on post-flocculation dewatering of fluid fine tailings by external mechanical forces as encountered in centrifuge and filtration.
Author/Creators:
Wang, Chen
Title:
Effects of colostrum management practices on the neonatal dairy calf
Description:
The timely feeding of an adequate volume of high quality colostrum immediately after birth is one of the key factors influencing the health and survival of the neonatal dairy calf. Therefore, the aim of this thesis was to investigate the effect of current colostrum management practices on the passive transfer of IgG, intestinal bacterial colonization, and the presence of bovine colostrum oligosaccharides (bCOs) in the gastrointestinal tract (GIT) of neonatal calves. In order to assess the effect of delaying the first colostrum meal, in chapter 2 calves were fed pooled, pasteurized colostrum at either 0 h, 6 h, or 12 h of life. Results indicated that feeding colostrum at 6 h and 12 h decreased the passive transfer of IgG when compared to calves fed at 0 h. Yet, no differences were observed in passive transfer between 6 h and 12 h calves, indicating that between 1-6 h of life the absorptive capacity of the intestine may decrease, thus leading to similar IgG concentrations in these groups. In addition, at 51 h of life, 12 h calves tended to have a lower prevalence of bacterial groups in the colon, specifically Bifidobacterium and Lactobacillus, suggesting that delaying the delivery of colostral nutrients may impact early life microbial colonization. In chapter 3, the effect of heat-treatment of colostrum on the concentration of oligosaccharides in bovine colostrum and in the intestine of neonatal calves was assessed. Results revealed that heat-treatment at 60°C for 60 min increased the concentration of free bCOs when compared to unheated colostrum. It is hypothesized that this may be due to the cleavage of bCOs from proteins and lipids in colostrum during heat-treatment. In contrast, calves fed heat-treated colostrum displayed a lower concentration of bCOs in the small and large intestine at 6 h of life compared to calves fed unheated colostrum. This result may be due to the metabolism of bCOs as a carbon source for beneficial intestinal bacteria, however further research is needed. The results of this thesis have a significant impact on the dairy industry as it demonstrates that delaying the first feeding of colostrum – even by increments of 6 h – can have a large influence on the neonatal calf. Moreover, it emphasizes potential prebiotic compounds that may be used to improve gastrointestinal health during the early life of the dairy calf.
Author/Creators:
Fischer, Amanda J
Title:
Strengthening Associations to Pictures vs. Words: The Case for Promoting Fruit and Vegetable Consumption to Men
Description:
It is well known that fruit and vegetable (FV) consumption is a protective factor against chronic health conditions; however, men tend to eat fewer fruit and vegetables than women. Since FV consumption helps prevent chronic diseases and many men do not eat enough, ways to improve the behaviour are needed. It may be that men’s implicit (i.e., automatic) and explicit associations towards healthy foods are different from women’s. Investigating methods of changing men’s associations to healthy foods will inform health campaigns on the content they should use. This study compared the effects of associative learning using picture stimuli (Picture-AL) or word stimuli (Word-AL) on automatic associations between apples and snackbars and healthy and unhealthy attributes in 120 men recruited at the University of Alberta campus. Automatic associations were measured by two versions of the Implicit Association Test (IAT). One version used picture-stimuli (Picture-IAT) and the other used word stimuli (Word-IAT). The stimuli used in the Picture-AL and Word-AL matched the stimuli in the Picture-IAT and Word-IAT respectively. The target and attribute categories were ‘apple+healthy’ and ‘snackbar+unhealthy’. The moderating effects of healthy-eating schema, changes in explicit associations and the relationship between the associations and actual snack choice between apples and snackbars were also examined. Results showed AL using picture or word stimuli had no differential effects on automatic associations to pictures or words; however, the strength of associations between pictures were moderated by self-schema. Findings were inconclusive on whether the associations to pictures or words are more predictive of food choice behaviour. The implications are discussed in terms of the Reflective- Impulsive Model and the meaning for health campaigns targeting FV consumption in men.
Author/Creators:
Evans, Sarah C
Title:
Trembling aspen (Populus tremuloides) leaf litter decomposition under simulated nitrogen and sulfur deposition in a mixedwood boreal forest
Description:
As one of the largest oil sands deposits in the world, the Athabasca oil sands region (AOSR) has generated and released large amounts of nitrogen oxides (NOx) and sulfur dioxide (SO2) to the atmosphere and the surrounding area. Long-term N and S deposition at elevated rates can cause soil acidification, decrease forest productivity, and change plant community composition. Litter decomposition is an important component of nutrient and carbon (C) cycling in terrestrial ecosystems which relate to forest productivity and greenhouse gas emissions. Litter decomposition rates are affected by many factors such as climate, litter chemistry, N and S addition, soil properties, and litter enzyme activities. To better understand how N and S deposition impacts litter decomposition in a boreal forest, I conducted laboratory (100-day) and field (18-month) experiments in this study. Litter and forest floor (F and H layers, after removing current litter layer) samples were collected from a mixedwood boreal forest located about 100 km southeast of Fort McMurray, northern Alberta. Litter C, N and S concentrations were determined using an elemental analyzer. Litter lignin concentration was analyzed by measuring absorbance at 280 nm following acetyl bromide digestion. Other elemental concentrations including calcium (Ca), magnesium (Mg), aluminum (Al), and manganese (Mn) were determined using an ICP-MS method. The MBC and MBN concentrations from the forest floor were determined using a fumigation-extraction method. Extracellular enzyme activities involved in C, N and S cycling were analyzed using fluorimetric and colorimetric methods: β-1, 4-glucosidase (GLU, enzyme classification (EC) EC 3.2.1.21) for C, β-1, 4-N-acetylglucosaminidase (NAG, EC 3.2.1.14) for N, and arylsulfatase (ARS, EC 3.1.6.1) for S. In the laboratory study, 10 years of N and S deposition changed trembling aspen (Populus tremuloides) litter chemistry and forest floor microbial properties. Cumulative CO2 emission (Ccum) from the litter was negatively correlated with C/N and lignin/N ratios in litter (P < 0.05), but not with forest floor microbial properties (P > 0.05). This laboratory study provided evidence that N and S addition can enhance litter decomposition through changed litter chemistry, suggesting that C cycling in the boreal forest ecosystem in the oil sands region can be significantly affected by long-term N and S deposition. However, these results need to be testified in the field. In the field study, N and S addition did not directly affect litter decomposition rates (P > 0.05) (Experiment I), and nutrient-induced changes in litter chemistry did not regulate litter decomposition rates under N and S addition (P > 0.05) (Experiment II). Litter N exhibited an immobilization phase followed by an initial release phase, while an initial leaching phase occurred followed by an immobilization phase until the end of study for S in both experiments. And extracellular enzyme activities in litter did not correlate with litter decay constants. To fully understand the effect of N and S deposition on litter decomposition, a long-term decomposition study is recommended.
Author/Creators:
Wang, Qi
Title:
Instance-dependent analysis of learning algorithms
Description:
On the one hand, theoretical analyses of machine learning algorithms are typically performed based on various probabilistic assumptions about the data. While these probabilistic assumptions are important in the analyses, it is debatable whether such assumptions actually hold in practice. Another question is whether these probabilistic assumptions really catch the essence of "learning" as is implicitly assumed since the introduction of PAC models in learning theory. On the other hand, when avoiding making assumptions about the data, typical analyses tend to follow a worst-case minimax approach, e.g. in the adversarial online learning framework. Oftentimes the results obtained will fail to catch and exploit the `niceness' of the data that may help speeding up the learning. It is also debatable whether the data encountered in typical learning scenarios would ever be truly adversarial. Motivated by the above issues, this thesis suggests to perform instance-dependent analysis of learning algorithms to improve our understanding of learning. Special emphasis is put on characterizing the `niceness' of data from the perspective of learning. In this thesis, we demonstrate this approach in three settings: 1. In the unsupervised learning setting, we redefine the problem of independent component analysis (ICA) to avoid any kind of stochastic assumptions and develop (for the first time) a provably polynomial-time learning algorithm based on our deterministic analysis. 2. In the supervised learning setting, we start with a statistical framework: We analyze the finite sample performances of the empirical risk minimization algorithm (ERM) for a generalized partially linear model under the random design setting. We detect a potential deficiency of the ERM algorithm. Further investigation leads to a high probability instance-dependent generalization bound. 3. Finally, in the online learning setting, we take a thorough analysis of the follow the leader (FTL) algorithm in the online linear prediction problem, and discover a broad range of previously unknown favourable conditions of the data under which FTL achieves a fast learning rate. Our approach leads to various instance-dependent results that are more general, expressive, and meaningful, in the sense that these results are able to catch the important factors of the data on which the performances of the learning algorithms heavily rely.
Author/Creators:
Huang, Ruitong
Title:
Structural and Functional Analysis of Intracellular Loop 5 of the NHE1 Isoform of the Na+/H+ Exchanger
Description:
The mammalian Na+/H+ exchanger isoform 1 (NHE1) is an integral membrane protein that regulates intracellular pH. It removes a single intracellular proton in exchange for one extracellular sodium ion. It has a large 500 amino acid N-terminal membrane domain that mediates transport and consists of 12 transmembrane segments with several membrane-associated segments including intracellular and extracellular loops. Extracellular regions of this domain are believed to contribute to sodium coordination. Intracellular loops may coordinate protons and modulate the sensitivity to intracellular pH. In this study we characterized the structure and function of intracellular loop 5 (IL5) amino acids Gly431-Lys443. Mutation of eleven residues to alanine caused partial inhibition of transport; notably, mutation of residues R440A and I436A, demonstrated that these residues were critical for NHE1 function. The structure of a peptide of IL5 revealed that it is unstructured in DMSO, however in sodium dodecyl sulfate solution it possessed significant alpha helical character. A significant finding was that Lys438 was in close proximity with Trp434 residue. Overall our results show that IL5 is a critical intracellular loop, with a propensity to form an alpha helix, with many residues being critical for proton transport.
Author/Creators:
Wong, Ka Yee
Title:
The role of teleost neutrophils in the regulation of inflammation
Description:
The inflammatory response is a complex biological process initiated following the recognition of noxious stimuli. It is composed of an elaborate cascade of both pro- and anti-inflammatory mediators, essential for effective defenses against infection, the removal of damaged cells, and the initiation of tissue repair processes. At the core of these responses is phagocytosis, an evolutionarily conserved mechanism critical to immune defense and the maintenance of homeostasis. Phagocytosis is initiated through the recognition of large particles (>1μM) by receptors on the cell surface, leading to actin polymerization, particle internalization, and a diverse array of downstream responses. Neutrophils are essential effector cells that form the first line of defense against invading pathogens. The main objective of my thesis research was to characterize the functional roles of teleost neutrophils, where various mechanisms are involved in the induction of pro-inflammatory responses, the regulation of inflammation, and neutrophil-driven mechanisms of resolution. Similar to mammalian phagocytes, I found that goldfish and lamprey phagocytes contribute to both pro-inflammatory and pro-resolving responses ex vivo. However, I found significant differences with regards to the level of responsiveness to zymosan and apoptotic cells. Interestingly, goldfish phagocytes displayed a reduced sensitivity to apoptotic cells, instead displaying a greater induction of antimicrobial respiratory burst responses during co-stimulation. Moreover, teleost phagocytes remained as central contributors to the resolution phase of inflammation, even though they showcased an improved ability to induce strong antimicrobial inflammatory responses. When I began focusing on neutrophils, I found that the number of circulating neutrophils in teleost fish was far below their mammalian counterparts. Despite this, many other aspects of neutrophil biology and regulation remained the same. Within the hematopoietic tissue, I found that teleost neutrophils exist in a large storage pool, from which they rapidly exit, enter into circulation, and infiltrate the inflammatory site when called upon. It has previously been shown that both mammalian and teleost macrophages exhibit extensive roles in inflammatory control. Interestingly, I demonstrated that neutrophils alter their phenotype throughout the acute inflammatory response, and contribute to both the induction and the resolution of inflammation. Neutrophils isolated during the pro-inflammatory phase displayed elevated ROS responses and released inflammation-associated leukotriene B4. In contrast, neutrophils isolated during pro-resolution displayed low levels of ROS and released lipoxin A4. Notably, eicosanoid release by neutrophils played a role, at least in part, in regulating divergent macrophage responses, including inducing their uptake of apoptotic cells. These observations were then applied to study the teleost inflammatory response following infection with the natural fish pathogens, Aeromonas veronii or Mycobacterium fortuitum. Both bacteria have been associated with significant outbreaks in aquaculture, often leading to mass die offs. I found that similar to the zymosan model, neutrophils rapidly migrated to the site of infection. In addition, both pathogens stimulated the production of ROS in teleost neutrophils. However, neutrophils were only capable of significantly killing A. veronii, unlike M. fortuitum, which required the total population of leukocytes for significant elimination. However, most interestingly, was the capacity of neutrophils to internalize dying macrophages previously incubated with A. veronii, despite remaining unable to internalize other forms of apoptotic cells. Notably, following the uptake of dying macrophages, neutrophils remained viable and increased their production of ROS, remaining pro-inflammatory in nature. Overall, the examination of the teleost inflammatory response mounted against pathogen mimics and natural bacterial infections provides additional insights into the complex mechanisms by which neutrophils operate within an inflammatory site and contribute to the induction and regulation of acute inflammatory responses.
Author/Creators:
Havixbeck, Jeffrey J
Title:
Structural Studies of Peptides that Influence the Pathogenicity of Bacterial Infections, and Investigation of Structure-Activity-Relationships of Antimicrobial Peptides with Application to Cancer Therapy.
Description:
Enterocin 7 is a two-component, leaderless bacteriocin comprised of an A and B peptide and produced by Enterococcus faecalis 710C. The secondary structure of enterocin 7B was investigated through circular dichroism. A high degree of α-helicity was discovered by circular dichroism, regardless of solvent. The solution structure of enterocin 7B was solved based on NMR spectroscopic data. The peptide was found to consist of three amphipathic α-helices, confirming the high degree of helicity predicted by circular dichroism. The overall structural fold in enterocin 7B was identified in other leaderless and circular bacteriocins and is a privileged motif in these classes of antimicrobial peptides. Subtilosin A is a circular, sactibiotic bacteriocin isolated from Bacillus subtillus JH642. This highly hydrophobic peptide of 34 amino acid residues contains three thioether bonds between the sulphur of cysteine side chains, at position 4, 7, and 13, and the α-carbon of partnering amino acids (Phe31, Thr28, and Phe22, respectively). A previous study of the solution structure of subtilosin A determined the stereochemistry of each α-carbon of Phe31, Thr28, and Phe22 to be D, D, and L, respectively. The all D energy minimization calculation was very close in energy to the reported D,D,L isomer, and therefore the crystal structure of this peptide is desirable. The solubility of subtilosin A was investigated; cyclodextrins were used as additives to increase the solubility of subtilosin A. A biotin bioconjugate of subtilosin A was synthesized to use as a non-covalent co-crystallization partner with streptavidin. A Meldrum’s acid derivative was synthesized to conjugate subtilosin A with carbonic anhydrase for use as a covalent co- crystallization partner. Efforts are underway to optimize the linkage between subtilosin A and carbonic anhydrase using the Meldrum’s acid derivative. Phenol-soluble modulins are virulence factors produced by a wide variety of staphylococcus bacteria. Of particular interest are the phenol-soluble modulins produced by the multi-drug resistant Staphylococcus aureus. Phenol-soluble modulins α1, and α3 were synthesized by solid phase peptide synthesis and phenol-soluble modulin β2 was isolated as a fusion protein with the small-ubiquitin like modifier protein that was subsequently cleaved. The secondary structure of these peptides was investigated using circular dichroism. Each peptide was found to be α-helical in a solution of 50 % trifluoroethanol: water. The solution structure of each peptide was solved using NMR spectroscopic data. Phenol-soluble modulins α1, and α3 were each found to be a single amphipathic α-helix and phenol-soluble modulin β2 was found to be comprised of three amphipathic α-helices that pack in such a way as to give a hydrophobic core and hydrophilic surface. The structure of phenol-soluble modulin α1 differed slightly from a predicted structure previously reported. Phenol-soluble modulin β2 was found to be primarily α- helical, despite the low values of α-helicity predicted by circular dichroism. Neopetrosiamide A and B are tricyclic peptides isolated from the marine sponge Neopetrosia spp. These peptides are potent metastasis inhibitors and they differ from one another only in the stereochemistry of the sulfoxide moiety of the oxidized methionine at position 24. Analogues of these peptides in which the methionine sulfoxide is replaced with various non- canonical and canonical amino acids revealed reduced or abolished activity, suggesting a mechanistic ‘hot-spot’ of this peptide. Efforts to reduce the synthetic steps required to form the three disulfide bridges by substituting the cysteine residues with hydrophobic residues were unsuccessful, indicating that the native neopetrosiamide is held tightly together by the three disulfides. Attempts to isolate and identify the biological receptor of neopetrosiamides through fluorescent labeling were unsuccessful. New folding studies using structure inducing solvents did not greatly improve the global oxidation of the cysteine residues to the correct disulfide connectivity. However, the use of chaotropic salts improved the global oxidation, resulting in a 1:1 mixture of desired neopetrosiamide with correct disulfide connectivity to undesired neopetrosiamide with incorrect disulfide connectivity.
Author/Creators:
Towle, Kaitlyn M.
Title:
A Novel Method of Measuring Refractory Black Carbon Mass and Number Distributions by Inversion of CPMA-SP2 Data
Description:
A new method of examining mass and number distributions of nanoscale refractive black carbon (rBC) particles has been developed. This method will be useful for atmospheric scientists conducting semi-continuous measurement of atmospheric rBC. The new method uses a Centrifugal Particle Mass Analyzer (CPMA) and Single Particle Soot Photometer (SP2), coupled with a novel inversion algorithm. The CPMA classifies particles by total mass to charge ratio, and the SP2 measures the mass of rBC in each individual particle. To recover the true rBC and total particle mass and number distributions, an inversion is required which accounts for multiple charging of particles and the CPMA transfer function. The inversion solves an inverse problem characterized by a Fredholm integral equation, where the true number and mass distribution of the aerosol is unknown, however both the system response and mathematical model of the CPMA-SP2 system are known. The inverse problem was solved using iterative methods, and a two variable number distribution was used to represent number concentration as a function of both rBC and total particle mass. The inversion was tested and validated using laboratory experiments, where the CPMA-SP2 sampled from a smog chamber. Sampling populations of uncoated, coated, and mixed coated-uncoated rBC particle populations was conducted. Finally the inversion was tested on data gathered in the real world during a field campaign in Shanghai, China. The results for three cases of high, medium, and low pollution levels, showed distinct populations of rBC particles, which are a function of rBC released from different sources and having different atmospheric residence times. The real world results showed this method can give valuable insights for atmospheric scientists using semi-continuous data logging. Future work will involve packing the software into a convenient form for use by CPMA-SP2 users.
Author/Creators:
Broda, Kurtis N
Title:
Automated Tool for Visual Progress Monitoring in Construction
Description:
This thesis focuses on determining innovative computer vision algorithms suitable for progress tracking and forming them into automated visual progress tracking framework. The main concept of this approach is reconstruction of an as-built 3D point cloud model of the object of interest based on the spatial information extracted from photographs or videos. The reconstructed as-built model is then compared to the as-planned model, and the progress is reported based on correlation of the as-built and the as-planned models. The perspective framework key components are Structure from Motion, Multi-View Stereo, Coherent Point Drift or Iterative Closest Point, and the Hausdorff distance. At the initial phase, Structure from Motion takes a set of images as an input, estimates camera parameters for each image and produces a sparse point cloud. Next, the obtained data passes to Multi-View Stereo and the dense point cloud is generated. At this stage, the acquired point cloud is the as-built model. The next phase is aligning of the reconstructed as-built model to the corresponding as-planned model. The alignment transformation is calculated with either Coherent Point Drift or Iterative Closest Point. Finally, having the point cloud aligned, the progress is estimated. This phase is performed in three steps. First, the Hausdorff distance is calculated. Second, the as-planned model is color coded with a binary palette, where one color corresponds to the completed parts of the construction object and another corresponds to the parts that are to be built. Third, the ratio of completed points to the number of all points is computed. Finally, the color-coded progress model and percentage of completion are reported to the end user. The perspective cutting edge libraries for Structure from Motion are COLMAP, OpenMVG, VisualSFM, TheiaSFM, and MVE. The chosen libraries for Multi-View Stereo are COLMAP, OpenMVS, CMVS, CMPMVS and MVE. The libraries selected for point cloud alignment are CPD (Coherent Point Drift) and libpointmatcher (Iterative Closest Point). Finally, the Hausdorff distance is computed with Meshlab. The chosen libraries are integrated into frameworks and tested on real case study data obtained from a construction company. The case study experiment indicated successful performance of the following frameworks: COLMAP-COLMAP-CPD-Meshlab, COLMAP-COLMAP-libpointmatcher-Meshlab, and OpenMVG-OpenMVS-CPD-Meshlab. These pipelines demonstrated their capability of performing reliable and fast progress identification. Thus, the specified software combinations are suggested for construction progress tracking. The proposed frameworks improve the cutting-edge computer vision construction project progress monitoring approaches in terms of reconstruction quality and computation time. In fact, the suggested progress monitoring approach allows to reduce progress identification time from a few hours to a few minutes.
Author/Creators:
Martens, Oleksii
Title:
Multi-Level Knowledge Extraction and Modeling to Support Job Hazard Analysis Process for Oil and Gas Pipeline Projects
Description:
Construction projects are impacted negatively by construction safety incidents. Job hazard analysis (JHA) process is a critical process component of safety management system in the construction industry. The JHA process is a planning process that aims to address potential hazards associated with execution of construction activities. It involves collecting knowledge from several safety knowledge resources. Explicit resources such as safety manuals, safety codes and regulation, and safety best practices are the primary input knowledge. In addition, tacit safety knowledge that is related to the experience of construction professionals is a critical knowledge component that feeds into the JHA process. JHA documents is the output of each JHA process for each construction activity. The construction industry is a very dynamic and complex environment. Collecting knowledge to perform JHA process requires time and significant efforts. Construction personnel do not have the same experience and ability in identifying construction hazards. In addition, new construction manpower is continually joining the workforce and they lack sufficient experience and knowledge required for hazard identification. Previous JHA documents, which were prepared in previous projects, contain valuable knowledge related to construction hazards. Currently, documents are scattered and not reused for future JHA processes. Oil and Gas Pipeline Projects consist of risky construction activities that involve dynamic interaction between humans, heavy construction equipment, heavy material, and the complex surrounding environment. Currently, safety research related to nonbuilding construction projects is not sufficient. Nonbuilding projects such as pipeline construction and complex infrastructure need research focus due to their execution complexity and high potential risks. This research aims to introduce a method for hazard knowledge extraction and modeling to assist and make the JHA process more consistent and systematic. To reuse the hazards knowledge embedded in JHA forms, multi- levels of knowledge extraction are performed. Text mining is used to organize documents in classes by adopting two stages of machine learning algorithms, clustering and classification. Moreover, JHA forms’ contents were analyzed to extract hazards’ concepts and relationships to build a hazard dictionary and knowledge schema. Text mining for concept extraction is used along with qualitative approach to build hazard dictionary. Ontology modeling is used to model the extracted knowledge schema. The model aims to represent the knowledge concepts, taxonomies, and semantic relationships. The knowledge model will support the JHA process by enabling retrieval and communication of hazards knowledge in future projects.
Author/Creators:
Altawil, Shadi N A
Title:
Block Copolymer Nanolithography
Description:
The development of photolithography has been the main driving force of the semiconductor industry to keep pace with Moore’s Law for over five decades. The theoretical resolution limit of state-of-the-art 193 nm photolithography is about 36 nm (half pitch). By integrating multiple patterning technologies, the semiconductor industry has now successfully extended the resolution of photolithography to 14 nm half-pitch. Innovative and cost-effective patterning technologies need to be developed for sub-14 nm patterning. Directed self-assembly, referred to as DSA, of block copolymers is a patterning technology that is able to form 5 - 200 nm patterns spontaneously, at low cost. It is one of two potential solutions for low cost sub- 20 nm half-pitch lines and spaces patterning, in 2017, and one of four potential solutions for sub-14 nm half-pitch patterns by 2019, according to the International Technology Roadmap for Semiconductors, 2015 edition. Moreover, directed self- assembly of block copolymers has already been demonstrated on 300 mm wafers, and a fully automatic lithography system for finFET, bit patterned media, and contact hole applications. This thesis is divided into two parts. The first part deals with understanding the annealing process of block copolymer self-assembly, the critical step in which the actual nanoscale phase segregation takes place. First, the mechanism of microwave annealing of block copolymers on silicon was studied and elucidated. In this work, it was discovered that the semiconductor itself is the source of heating and not the polymer, contrary to the reports in the literature. In the next phase of this part of thesis, a new solvent flow annealing system with in situ laser reflectometry and an optical microscope was developed. By integrating a feedback loop, this system is able to control the swelling/deswelling rate, degree of swelling, and annealing time to accurately control the annealing conditions to eliminate the formation of dewetting or double layers, leading to much improved reproducibility. Multi-step swelling and deswelling in an individual process run have also been demonstrated. In the second part of the thesis, the concept of density multiplication was examined. Density doubled and tripled dot patterns are studied, as a means of creating more complex patterns that could be attained with single step annealing. The quality of the resulting dot patterns was analyzed and a theoretical model was developed to predict the quality of density doubled and tripled patterns using only two parameters obtained from single layer patterns. As an intriguing extension of this work, the orientational relationship between sequentially deposited BCP dot patterns with different pitches was investigated. From large scale helium-ion microscope images, it was found that preferential orientations, or Moiré patterns, are formed, which is determined by the pitch ratio and dot size.
Author/Creators:
Jin,Cong
Title:
Posterior Cranial Base Growth and Development Changes as Assessed Through CBCT Imaging in Adolescents
Description:
Introduction: Understanding craniofacial growth and development is important for accurate diagnosis, treatment planning and post treatment evaluation of orthodontic cases. Paramount to this is knowledge of the cranial base growth and development, since it is the foundation upon which the remaining facial structures develop. In this study, a systematic review was conducted to gather knowledge about previous data on growth changes in the posterior cranial base. Inter-rater, intra-rater and accuracy of 33 selected landmarks in the posterior cranial base and surrounding area were then evaluated via three-dimensional (3D) cone beam computed tomography (CBCT). An adolescent population was then used to assess growth related dimensional changes of the previously selected landmarks. Methods: Systematic review was conducted via the PRISMA guidelines. Reliability and accuracy were assessed using CBCT’s of 10 dry skulls. Sixty (60) CBCT images of the adolescent population at two time-points were used to assess growth related dimensional changes using the 33 selected landmarks. Results: The selected landmarks in the posterior cranial base and surrounding area were found to be reliably and accurately located in 3D. Over the growth period studied (17.5months), minor statistically significant changes occurred, but they were deemed clinically irrelevant. Conclusions: The studied landmarks in the posterior cranial base and surrounding area showed minor, but potentially important, clinically insignificant changes over the relatively study period. The observed changes could be attributed to measurement error. The posterior cranial base is deemed to be stable in all three dimensions of study during the adolescent growth period studied, but over a longer time frame may show continued growth.
Author/Creators:
Currie, Kristopher S
Title:
Using a native plant-pathogen system as a model to investigate success of the invasive mountain pine beetle in jack pine
Description:
Tree-infesting organisms have recently expanded their ranges into many novel habitats where they will not only interact with new host tree species, but also with a myriad of other organisms that also share these hosts. Understanding the major factors and mechanisms that mediate plant-herbivore-pathogen interactions, such as plant defenses, will be important for determining the impact of invading organisms. My research investigates the range expansion of mountain pine beetle (Dendroctonus ponderosae (Hopkins), Coleoptera: Curculionidae, Scolytinae) into the novel host jack pine (Pinus banksiana Lamb.), which is an ecologically and economically important component of the Canadian boreal forest. First, I assessed the effects of drought on induced plant defense responses in jack pine to phytohormones (as a proxy for different classes of biotic disturbances) and a pathogenic fungal associate of mountain pine beetle, Grosmannia clavigera (Robinson-Jeffrey & Davidson). Prior induction from phytohormones resulted in systemic cross-induction of resistance to G. clavigera under normal watering treatment, but susceptibility under low watering treatment. Next, I identified the impact of multiple classes of induced host defense compounds due to the infection by a widespread native parasitic plant (dwarf mistletoe, Arceuthobium americanum Nutt. ex Engelm.) on the success of mountain pine beetle and G. clavigera. Systemically, there was a non-linear effect of dwarf mistletoe infection on monoterpenes, with increasing concentrations of monoterpenes at moderate severities and decreasing concentrations at high severities. Dwarf mistletoe-induced changes in monoterpenes seem to result in the systemic induced resistance as trees with moderate mistletoe severity were most resistant to G. clavigera. In contrast, phenolic compounds increased in amount with greater dwarf mistletoe infection severity but decreased after inoculation with G. clavigera. This inverse response to infection between monoterpenes and phenolics suggests that phenolics are detoxified by the fungus or there are tradeoffs between these two major defense classes. Furthermore, dwarf mistletoe-induced changes in defensive and physical characteristics reduced the competitive advantage of the subcortical insect community on mountain pine beetle performance. Tree-mediated interactions between biotic disturbances, such as dwarf mistletoe, and G. clavigera may impact mountain pine beetle establishment or maintenance in novel jack pine forests through systemic effects and coordination of defense chemicals.
Author/Creators:
Klutsch, Jennifer G.
Title:
Gender differences in adolescent anxiety symptoms: Interactions between peer experiences and individual characteristics
Description:
Anxiety is the most common mental health concern among children and adolescents globally. Anxiety symptoms such as fears and worries increase markedly in early adolescence, particularly for girls. However, not all early adolescents experience this increase in anxiety symptoms. Guided by the developmental psychopathology framework, this study examined risk and protective factors at the peer and individual levels that may influence anxiety symptoms in early adolescence. The first goal was to describe short-term person-level fluctuations in anxiety symptoms over eight weeks during the Spring term of Grade 7. The second goal was to examine bi-weekly co-variation between adolescents’ anxiety symptoms and their peer experiences (peer victimization, friendship closeness). The third goal was to investigate the main and moderating effects of individual characteristics (self-blaming attributions, social competence) on anxiety symptoms and on the co-variation between peer experiences and anxiety symptoms. The fourth goal was to examine gender differences in these associations. These research goals were addressed using a series of two-level hierarchical linear models. Participants were 180 ethnically diverse adolescents (60.6% girls; mean age = 12.7 years, SD = .44 years) in 2 large junior high schools. Results indicate although both girls and boys experienced significant fluctuations in their anxiety symptoms across the eight weeks, girls experienced greater fluctuations. Further, on weeks when adolescents experienced more frequent peer victimization, they also concurrently experienced more frequent anxiety symptoms. Adolescents who made more self-blaming attributions also experienced more frequent anxiety symptoms, whereas more socially competent adolescents experienced fewer anxiety symptoms. Closeness in adolescents’ friendships did not co-vary with their anxiety symptoms. Furthermore, neither self-blaming attributions nor social competence moderated the associations between adolescents’ anxiety symptoms and their peer experiences. There were also no gender differences in these associations. Overall, these findings expand current understanding of early adolescent anxiety symptoms by focusing on person-level variability in anxiety. How these findings parse the complex interplay between gender, and peer and individual risk and protective factors are discussed within the context of developmental psychopathology.
Author/Creators:
Hosan, Naheed
Title:
Statistical Methods To Study Turbulence In The Magnetized Interstellar Medium
Description:
It has been well known that turbulent motions are ubiquitous in the interstellar medium. These motions are very important in governing various astrophysical processes like star formation. Both observational and numerical studies are important to understand turbulent motions, and a gap between these two studies exists. To bridge this gap, various statistical techniques have been developed. These techniques so far have assumed isotropy and homogeneity in space. While this assumption is good in the absence of magnetic fields, isotropy is broken in the presence of magnetic field as the direction of magnetic field breaks the symmetry in space. In this thesis, we have developed an extension to current statistical techniques, which use intensity maps, such as velocity channel analysis and velocity centroids, to study turbulence anisotropy, and have discussed how statistical anisotropy of intensity maps can be used to study media magnetization, and separate different fundamental MHD modes: Alfven, fast and slow modes.
Author/Creators:
Kandel, Dinesh
Title:
Effects of Low Fat Versus High Fat Cheese on Glucose Homeostasis and Hepatic Lipid Metabolism in Prediabetic and Type 2 Diabetic Rats
Description:
Background: Type 2 diabetes (T2D) is a disease characterized by insulin resistance and pancreatic beta cell failure. Lifestyle interventions, including dietary interventions, are the first line of treatment for this disease. At present, Canada’s Food Guide recommends choosing low fat cheese over high fat cheese, however, current literature suggests a more complex relationship exists between cheese consumption and risk of T2D. Several fatty acids abundant in cheese have been shown independently to have beneficial effects on glucose homeostasis. Therefore, it is of particular interest whether low fat cheese and high fat cheese affect diabetes outcomes differently. Objectives: (1) To determine the impacts of cheese feeding on in vivo responses to glucose and insulin in prediabetic and T2D rats. (2) To explore the mechanisms by which cheese affects metabolism in prediabetic rats using an untargeted metabolomic analysis. (3) To use the results of the in vivo studies and metabolomics assays to direct additional investigations of the effects of cheese feeding in prediabetic rats. Methods: Two cohorts of rats, one prediabetic model (8-week old Sprague Dawley rats), and one T2D model (retired male Sprague Dawley breeder rats, 5-6 months old), were used. For each cohort, N = 64 animals were randomized to receive high fat diet (HFD) or low fat diet (LFD) for four weeks. In the T2D model, HFD rats underwent streptozotocin (STZ) administration at week 5 to induce a T2D phenotype. At the start of week 6, all HFD-fed animals (prediabetic and T2D models) were randomized to either continue on HFD or begin one of two cheese diets: HFD + high fat cheese (HFD+HFCh), or HFD + low fat cheese (HFD+LFCh) diet. HFD and cheese diets were isocaloric and matched for macronutrient composition. After 7-8 weeks of feeding, rats underwent either an oral glucose tolerance test (OGTT) or insulin tolerance test (ITT), and were euthanized the following week for tissue collection. In the prediabetic cohort, serum was sent for metabolomic analysis, and both the serum and liver lipidome were analyzed. Further, histology was conducted in a sub-sample of prediabetic rats’ livers. Results: Food intake and body weight were similar between groups in both cohorts. There was no effect of diet on HOMA-IR, glucose-insulin AUC index, or fasted insulin and glucose in either cohort. In the T2D cohort OGTT blood glucose was significantly higher in the HFD+HFCh group and HFD groups, relative to LFD, while HFD+LFCh was not. In the prediabetic cohort, both HFD+LFCh and HFD+HFCh groups demonstrated improved insulin sensitivity relative to HFD during an ITT, while OGTT blood glucose was unaffected by diet. Metabolomic analyses revealed alterations in several phosphatidylcholine metabolites in serum of cheese-fed, prediabetic rats, while overall serum lipids remained unaffected by diet. Hepatic triglyceride accumulation was increased in prediabetic HFD+LFCh, with cholesterol ester accumulation also increased, but not reaching significance. A similar trend was observed in HFD+HFCh. Liver histology revealed markedly increased oil red-O staining in the livers of prediabetic animals fed cheese. Conclusion: T2D rats that consumed HFD+LFCh had improved glucose tolerance that was not explained by body weight or insulin tolerance changes. Prediabetic rats that consumed either HFD+LFCh or HFD+HFCh demonstrated improved insulin sensitivity during an ITT. These rats also demonstrated increased liver triglyceride and cholesterol ester accumulation. This may have been due to altered phosphatidylcholine metabolism. These data suggest that either HFCh or LFCh may improve insulin sensitivity in a prediabetic model, while only LFCh improves glucose tolerance in a model of T2D.
Author/Creators:
Hanning, Anik R. Z.
Title:
Soil microbial communities in northern Alberta's boreal forest floors following resource extraction
Description:
Land disturbance linked to resource extraction in Alberta ranges in severity from full ecosystem removal during surface mining to more surficial disturbance during clearcut timber harvesting. Changes to these ecosystems affect the soil microbial community, and the health of boreal forests is largely dependent on the soils in which they grow. Microbial communities are responsible for the decomposition and mineralization of forest litter, which converts major nutrients to useable forms for vegetation, thereby cycling the nutrients through the ecosystem. Phospholipid fatty acid (PLFA) and multiple substrate induced respiration (MSIR) analyses were used to assess the structural and functional diversity of forest floor soil microbial communities in two disturbed boreal forest ecosystems: (1) in a clearcut harvested stand 17.5 years post-harvest, and (2) in a 31 year chronosequence of reclaimed soils following surface mining. Disturbed stands were compared to their undisturbed counterparts in both forest ecosystems. In the harvested area, trembling aspen (Populus tremuloides) was the dominant tree species regenerating in both aspen and spruce (Picea glauca) clearcuts. PLFA and MSIR analyses demonstrated the importance of aspen stand regeneration on spruce clearcuts and its influence on soil properties. In both clearcuts, microbial communities exhibited comparable functional diversity, and a structure more similar to the communities in undisturbed aspen forest floors than undisturbed spruce. In the surface mined area, the novel forest floor that developed atop the peat-mineral coversoil was key to the reestablishment of a microbial community with different structure, yet similar biomass and function to that present in undisturbed soils.
Author/Creators:
McKenzie, Cassandra, E
Title:
Predicting academic achievement and cognitive ability from child and parent perceptions of ability.
Description:
Cognitive ability is the best predictor of academic achievement however, a large proportion of the variance with respect to academic achievement remains unexplained. Research has recently focused on motivational variables such as ability perceptions in an effort to better understand the unexplained variance in academic achievement. Past studies have demonstrated the importance of self-perceptions of ability in the prediction of academic achievement above and beyond general cognitive ability in multiple academic domains. Similarly, parents’ perceptions of their child’s ability have been shown to be a powerful predictor of the academic achievement. No studies, however, have examined both and parent perceptions of ability across a variety of domains yet. Therefore, the present study aimed to address past limitations and thereby systematically examine the extent to which children’s self-perceptions of ability and parents’ perceptions of their child’s ability in the areas of reading, writing, mathematics, overall academic achievement and cognitive ability predicted their objectively measured ability in these areas. A sample of 23 children and their parents completed self and parent perception of ability questionnaires. Results indicated children were only able to accurately predict their own reading ability whereas parents were able to accurately predict their child’s ability in the areas of writing, math, overall academic achievement, and general cognitive ability. Future research should consider including teacher perceptions of ability as a separate valuable source of information with respect to a child’s academic achievement. In practice, perhaps having parents foster their child’s perception of their own ability will enhance the child’s self-perception and ultimately allow the child to reach their academic potential.
Author/Creators:
Kennedy, Kathleen E
Title:
Heat and pressure resistance of Escherichia coli
Description:
Strains of Escherichia coli may survive heat or pressure stress, acquire specific virulence genes and cause severe human diseases. The locus of heat resistance (LHR) has been identified as an important heat resistant element in E. coli. The objective of this thesis was to explore the role of the LHR on heat and pressure resistance of E. coli, as well as its relationship with protein folding and aggregation, and evaluate the effects of food matrix and antimicrobials on pressure resistance of E. coli. To explore the heat and pressure resistance related to protein folding and aggregation, the role of LHR was investigated in E. coli MG1655 expressing ibpA-yfp fusion. A total 10 proteins of LHR were detected through proteomic analysis using mass spectrometry, including two small heat shock proteins, two heat shock proteases, proteins of the YfdX family, thioredoxin, and a sodium/hydrogen antiporter. Microscopic observations showed that LHR reduced the inclusion bodies after heat or the pressure treatment, indicating that LHR proteins function to re-fold and turnover aggregated proteins. The proteomic analysis confirmed that the phenotype of pressure resistance of LHR occurred through stress regulation, mitigation of protein aggregation and reduction of oxidative stress. To evaluate the effect of food matrix on the pressure resistance of E. coli, the resistance of two five-strain cocktails to pressure in bruschetta, tzatziki, yogurt and ground beef was compared. Pressure reduced E. coli in plant and dairy products by more than 5 logs (cfu/mL) but not in ground beef. Food components calcium, magnesium, glutamate, caffeic acid and acetic acid exhibited a protective effect on E. coli after pressure treatment and during storage at 4 °C. Further study assessed the combined effect of antimicrobials and pressure on enterohaemorrhagic E. coli (EHEC) in pressure treated beef steaks. The thiol-reactive allyl-isothiocyanate (AITC) and cinnamaldehyde exhibited synergistic activity with pressure on E. coli. However, the membrane-active essential oil components carvacrol and thymol showed antagonistic or no synergistic effect with pressure. In conclusion, the LHR confers pressure resistance of E. coli, and the resistance is related to protein folding and aggregation. Moreover, pressure resistance of E. coli is affected by food matrix and antimicrobials.
Author/Creators:
Li, Hui
Title:
Replication and Its Application to Weak Convergence
Description:
Herein, a new methodology is developed to replicate functions, measures and stochastic processes onto a compact metric space. Each replica object is a weak or strong modification of the original object, so many results are easily established for the replica objects and then transferred back to the original ones. Two problems are solved within to demonstrate the method: (1) Finite-dimensional convergence to possibly non-cadlag limits is established for processes living on general topological spaces. (2) New tightness and relative compactness criteria are given for the Skorokhod space of Tychonoff-space-valued cadlag mappings. The methods herein are also used in companion papers to establish the: (3) existence of, uniqueness of and convergence to martingale problem solutions, (4) classical FKK and DMZ filtering equations and stationary filters, (5) finite-dimensional convergence to stationary signal-filter pairs, (6) invariant measures of Markov processes, and (7) Ray-Knight theory, all in general settings.
Author/Creators:
Dong, Chi
Title:
Relationship between Micro and Macro Mechanical Properties of Cemented Artificial Conglomerate
Description:
Micromechanics modeling is becoming more popular in geotechnical analysis. It allows engineers to understand the deformation and failure processes at the microscopic level. Due to the advancement of computer capacities and numerical methods for micromechanics analysis, engineers are able to perform micromechanics analysis on more practical problems. In order to perform these analysis, it is necessary to determine the micro mechanical parameters of the material. This research is focused on the theoretical and experimental development to determine the micro mechanical parameters of cemented granular material. In the theoretical analysis, the micro mechanical properties of geomaterials consist of several components. The contribution of each of these components to the overall macro behavior is dependent on the characteristics of each component. The strength of a cemented granular material consists of frictional strength between the grains, the bonding strength between the grains and the cement, and the bonding strength of the cement. It is assumed that the voids in a cemented granular material are occupied by cement, and the overall strength of the material can be calculated from the strength of each individual component. In this study, the theoretical relationship that relates the strength of each component to the overall macro mechanical strength of the cemented granular material has been developed. Experiments were conducted to measure the micro and macro mechanical parameters in the theoretical relationship for cemented granular material. Artificial conglomerate made up of steel balls and Portland cement was used to minimize the variation of grains and cementation properties in natural materials, and the possibility of crushing of grains under high stress. Direct shear, uniaxial/triaxial and Brazilian tensile tests were conducted to study the mechanical behavior and measure the macro parameters of artificial conglomerates. Microscopy analysis, 3D scanning and post-failure analysis were carried out to obtain the micro properties. In addition, an innovation approach was developed to measure the inter-particle friction angle of steel balls. Numerical simulation was performed to study the micro mechanical behavior of cemented granular material and it was further used to examine the theoretical relationship that relates the micro and macro mechanical parameters. Using calibrated micro properties, the numerical results show good agreement between theoretical calculations and laboratory measurements under different normal stresses. However, different micro parameters are required for modelling tests with samples of different particle sizes. This is due to the size dependent progressive failure mechanism in the micro model. Using measured micro properties as inputs, the calculated cohesions from the theoretical relationship are about 0.84 to 1.05 times of the measured values from direct shear tests. The calculated peak friction angles are about 10% to 15% higher than the measured values from direct shear tests. Since it is practically impossible to arrange particles in the experiment that is assumed in the theoretical relationship, this could be the reason that accounts for the differences between the calculated and measured values. The calculated cohesion and friction agree with the measured values in the laboratory, which supports the existence of a relationship between the micro and macro mechanical properties. The macro parameters of cemented granular material can be calculated with measured micro properties using the derived theoretical relationship. In addition, this study also provides the laboratory procedures to measure the macro and micro properties of cemented granular material.
Author/Creators:
Li, Yuan
Title:
Predictive Energy Management for Wireless Sensor Nodes
Description:
A wireless sensor network is a tool that can collect data, aiding in answering a number of different questions in research and industrial environments. When deployed in remote locations, it is often beneficial to use of energy harvesting technologies, allowing sensor nodes to replenish energy while in the field. This permits longer deployment times while keeping node size small. In order to make the best use of harvested energy, controllers can be used to adapt node activities to available energy. In this thesis, energy forecasts based on measurements of atmospheric pressure are created and included as inputs to fuzzy controllers. These controllers are applied to simulated sensor nodes and used to control node activity levels for effective use of available energy. They were tuned using differential evolution and simulated using measured meteorological data. The results were examined in terms of the networks overall activity level and the usage of reserve energy. With respect to the solar energy forecasts, a number of applied methods were able to achieve error levels comparable to other methods where more variables were included. The tuned fuzzy controllers represented an improvement over both the uncontrolled and human-created cases.
Author/Creators:
Rodway, James E A
Title:
A framework for assessing the safety performance of industrial projects using safety-related measures
Description:
Although previous research has emphasized the use of safety-related measures to assess and control safety performance, many construction companies continue to rely on reactive indicators for safety control. The reluctance of industry to use safety-related measures for the proactive evaluation of safety performance is a consequence of the unique characteristics of construction projects, which renders the identification and evaluation of safety-related measures difficult in practice. From a theoretical perspective, models developed to proactively assess the safety performance have difficult considering (1) the specific characteristics of an organization due to the limited amount of data points provided and (2) the dynamic nature of construction sites, which can affect measure performance. The objective of this research was to develop a framework that could proactively assess safety performance using safety-related measures. A framework, which combines Case-Based Reasoning (CBR) with simulation modelling, was proposed for this purpose. CBR was chosen as an assessment method for its ability to assess safety output under conditions of limited data, while simulation was considered for its ability to reliably reproduce project behavior. Prior to framework implementation, challenges for understanding current Safety Managements System (SMS) practices and identifying safety-related measures were researched. Then, a risk-rating approach designed to investigate the complex relationship between SMS factors and accident precursors from a holistic perspective was developed. This approach allows for not only the identification of high-priority SMS factors and accident precursors but also for the evaluation of associations between them, and a many-to-many relationship was found to exist between these groups. A case-study was then conducted to analyze and review the effective use of departmental data to control and assess safety performance. Several safety-related measures collected by several departments were found to be useful for proactively controlling safety performance. Altogether, the findings presented here strongly support the use of a holistic approach for the evaluation and control of safety performance The framework was developed and applied in an industrial construction organization. A total of 27 safety-related measures were identified from data collected from departmental databases, documents, and interviews. After reducing the dimensionality of the database through the application of statistical tests and Correlation Feature Based Selection Algorithm, the final approach considered nine measures. From a practical perspective, the model was found to reliably predict trends in safety performance, and can be used to predict how specific decisions made in practice can affect safety performance. This research has resulted in (1) the development of a CBR approach that can be used to assess the safety performance of construction projects characterized by few data points (i.e., few incidents) while allowing for the consideration of an organization’s unique conditions and (2) the integration of CBR with a simulation model, which allows managers to more easily predict how decisions, both individually and in combination, influence overall safety performance. Furthermore, the results of this research support the use of (3) a holistic approach for the establishment and evaluation of proactive SMS mitigation strategies and (4) the collection and consideration of various departmental data to more reliably evaluate proactive safety performance.
Author/Creators:
Pereira, Estacio Siemann Santos
Title:
Food (In)Security: Food Policy and Vulnerability in Kugaaruk, Nunavut
Description:
My research uses a framework of vulnerability and community economy to understand how Inuit practices of sharing need to be reflected in federal food policies for Inuit to be able to meet their food needs. I specifically draw on the work of feminist theorists such as Judith Butler, and Erin Cunniff Gilson, to consider how vulnerability that is expressed through acts of dependency and relationality can serve to meet peoples’ food needs. I also take up the work of feminist economic geographers J. K. Gibson-Graham to understand how community economic capacities in Kugaaruk are informed by and thrive through the practice of vulnerability. I interviewed a range of community members in Kugaaruk including elders, hunters, people who run community food programs, and people who use community food programs – all of whom are invested in mitigating high rates of food insecurity in the community. Food sharing, which is a long standing practice and an Inuit law, is an important aspect of successful food programming in the community and something that community members want to see continue, despite realities, such as high costs and ineffective policies, that make it a very hard practice to maintain. I argue that if the government is serious about helping reduce rates of food insecurity in Nunavut, they need to support existing community capacities that are based on Inuit values of sharing to ensure people are able to meet their food needs.
Author/Creators:
Daborn, Merissa L
Title:
Amino Acids Production for Galdieria sulphuraria Under Different Stressors
Description:
Amino acids are building blocks for protein synthesis and are essential to every metabolic process. A well-balanced diet is one in which all required amino acids are present in the food that is eaten. Unfortunately, this is not always the case and nutritional supplements can be used to make up the balance of the required amino acids. Supplements can be produced from different sources including animals, plants and microbial organisms. Animal sources such as fish and beef can generally be complete but require lengthy periods for growth and harvesting. These sources, however, are also susceptible to diseases and contaminations. Amino acids derived from individual plants do not form the basis for a complete diet and a mixture of plants is required for a healthy diet. This requirement is because individual plant proteins do not contain all nine of the essential amino acids in sufficient amounts. Microorganisms that have been used to produce amino acids include bacteria, fungus, and algae. These microorganisms can be genetically engineered to over produce specific proteins or amino acids. Algae has received much less attention than bacteria, yeast and fungi. The goal of this thesis is to establish a base case for amino acid production from non-genetically modified algae by investigating the effect of different growth parameters. The selection of the specific strain of algae is based on choosing a strain that can be cultured efficiently and economically. Algae can be divided into freshwater and saltwater environments, and both approaches have issues researchers must handle in growing and harvesting algae for protein production. For example, freshwater algae can be contaminated by a large number of microorganisms and the procedure for maintaining a monoculture free from contaminations is very difficult for mass production. On the other hand, saltwater algae have fewer contaminants than the freshwater algae but the operator must contend with control and disposal of salts in the growth media. The expanding need for natural ways to produce high amounts of amino acids is fueling the search for other strong and competitive microalgal strains. This study investigates Galdieria sulphuraria, a type of red algae that can thrive in harsh environments that not many microorganisms can tolerate. G. sulphuraria is an extremophile that requires both thermophilic and acidophilic conditions for proper growth; furthermore, G. sulphuraria can also be a halotolerant alga, which has the ability to grow in high salt concentration conditions. G. sulphuraria also has the ability to consume a wide variety of sugars and nitrogen sources. A Box-Behnken experimental design was used to investigate amino acid production in this algal strain with the manipulated parameters being sugar sources and concentrations of macronutrients (carbon, nitrogen and phosphate). The amino acids that are directly correlated to the concentration of these macronutrients are serine, histidine, arginine, valine, phenylalanine, isoleucine, leucine, and proline. A poor correlation was observed between the concentration of the manipulated macronutrients and the amino acids aspartic acid, glutamic acid, glycine, threonine, alanine, tyrosine, cysteine, methionine, and lysine. Different sugars influence amino acid productions, even with the same carbon number and molecular weight. G. sulphuraria fed with glucose has the capability to produce higher amino acid concentrations compared to the same medium with a substituted sugar type, mannitol, using equivalent molar mass. This response is strongly noticeable with a growth medium supplied with xylose, in which G. sulphuraria produces greater amino acid concentrations compared to arabinose. When G. sulphuraria is grown on xylose, after 48 hours, the culture contains more amino acids than was observed with the other three sugar types. The only exception was for the concentration of aspartic acid when compared to growth on glucose. In this case, when grown on xylose, the aspartic acid concentration decreased by 178%. The superior production of amino acids from a xylose containing medium, which has an increasing value of 70% for serine, 61% for histidine, 75% for arginine, 78% for valine, 71% for phenylalanine, 71% for isoleucine, 70% for leucine, 80% for proline, 48% for glutamic acid, 95% for glycine, 69% for threonine, 76% for alanine, 84 % for tyrosine, 74% for cysteine, 46% for methionine, and 80% for lysine, suggests that amino acid production is irrelevant to the number of carbons in sugars.
Author/Creators:
Fayadh, Abdullah
Title:
Development of Ir- and Rh-Catalyzed Deoxygenation and Carbene Cross Coupling Reactions of Allylic Carbonates
Description:
Transition metal-catalyzed allylic substitution reactions are widely used for the selective formation of new bonds. This class of reaction has been extensively studied with a variety of nucleophiles and under optimized conditions that will furnish product in high yield and with high chemo-, regio- and enantioselectivity. However, there remain opportunities for established catalyst systems to facilitate new transformations through the interception of metal π-allyl complexes with novel partners. This thesis describes two reactions of transition metal π-allyl species. The selective deoxygenation of alcohols is a persistent challenge in organic synthesis and a host of methods have been developed to address this problem. The use of [Ir(COD)Cl]2 (COD = 1,5 cyclooctadiene) and [Rh(COD)Cl]2 precatalysts in the presence of a diazene transfer agent, N-isopropylidene-N’-2-nitrobenzenesulfonyl hydrazine (IPNBSH), facilitated the reductive transposition of allylic carbonates with high regioselectivity and good to excellent yield. The reaction proceeded under mild conditions and was highly chemoselective. [Ir(COD)Cl]2 was effective for the deoxygenation of both alkyl and aryl monosubstituted allylic carbonates, including substituents potentially susceptible to decomposition by the transition metal. 1,3-Disubstituted allylic carbonates, including α,β–unsaturated esters, were reduced by [Rh(COD)Cl]2 and P(OPh)3. Interception of a π-allyl fragment by a diazo-generated carbene intermediate gave the net cross coupling 1,3-dieneoate products in good yield, and in some cases, with high selectivity for the thermodynamically disfavored E,Z isomer. Only a single, Ir precatalyst, which has not previously been reported to interact with diazo compounds, gave acceptable yield of product. This observation potentially represents a new mode of activity for a well understood catalyst system.
Author/Creators:
Thomas, Bryce N
Title:
Uncertainty in Life Cycle Assessments of Well-to-Wheel Greenhouse Gas Emissions of Transportation Fuels Derived from Various Crude Oils
Description:
Growing concern over climate change has created pressure on the oil and gas industry to reduce their greenhouse gas (GHG) emissions. Several life cycle assessment (LCA) studies have examined various crude oils in an attempt to determine which have the lowest and highest well-to-wheel (WTW) GHG emissions. The majority of these studies published deterministic point estimates with a limited sensitivity analysis. Due to the variation in results between studies and the lack of an uncertainty analysis, the usefulness of the results for policy makers and industry representatives is limited. The goal of this study is to expand on the previous research by identifying a realistic range of WTW emissions for various crude oils. This research builds on the previously published FUNdamental ENgineering PrinciplEs-based ModeL for Estimation of GreenHouse Gases in Conventional Crude Oils (FUNNEL-GHG-CCO). The FUNNEL-GHG-CCO model produced point estimates of the WTW emissions for five North American crude oils. This work makes improvements to the model, adds a Monte Carlo simulation to calculate uncertainty, analyzes additional scenarios to examine the effect of field age on WTW emissions, and expands the model to include three crudes from outside North America. A sensitivity analysis is used to identify sensitive inputs. Then distributions for the sensitive inputs are determined from the literature and used to run the Monte Carlo simulations. The resulting WTW emission ranges for gasoline are 95.3-99.9 (Saudi Arabia), 99.9-105.5 (Maya), 96.4-104.0 (Mars), 101.6-109.9 (Venezuela Low Steam), 101.1-109.2 (Sirri), 102.5-114.2 (Bow River), 104.6-114.5 (Alaska North Slope (ANS) historical), 105.5-113.2 (Kern historical), 113.6-138.5 (Venezuela High Steam), 133.2-163.2 (ANS current), and 131.5-155.0 gCO2eq/MJ (Kern current). For ANS and Kern, the current scenarios use lifelong average iii | P a g e production data and the historical scenarios use recent production data to illustrate how the WTW emissions change as the fields age. For the Venezuela crude, two scenarios are used as a wide range of steam-to-oil ratios appear in the literature. The results of this study will be beneficial to both policy makers and industry representatives. The results identify which pieces of information policy makers would require from industry in order to get accurate WTW emissions estimates. The uncertainty ranges provide a better understanding of how WTW GHG emissions vary between crude oils. This will help policy makers understand the limitations of such models.
Author/Creators:
Di Lullo, Giovanni R
Title:
Molecular dynamics insights into nanovoid behavior in metals: from sparsely-arranged nanovoids to densely-arranged nanopores
Description:
Atomistic-level study of void behavior in metallic materials is a difficult task for continuum-based methods. In contrast, MD method serves as an ideal tool for real-time computer simulation of all kinds of atomistic phenomena. More and more researchers become aware of this and a few have pioneered in the area of nanovoid simulation. Many problems were nicely addressed, yet not every stone has been turned. Particularly, we provided new understanding to the “shear impossibility” debate in light of our MD investigation. In this work, molecular dynamics simulation is applied to uncover mechanisms regarding the nucleation, growth and coalescence of nanovoids. Molecular dynamics results are examined by using the “relative displacement” of atoms. In doing so, the homogenous elastic deformation has been excluded. The “relatively farthest-travelled” (RFT) atoms characterize the onset of interfacial debonding and void growth due to dislocation formation. Our results indicate that the initiation of interfacial debonding is due to the high surface stress in an initially dislocation-free matrix. Through this approach, we also justified the feasibility of void growth induced by shear loops/curves. At a smaller scale, the formation and emission of shear loops/curves contributes to the local mass transport. At a larger scale, a new mechanism of void growth via frustum-like dislocation structure is revealed. A phenomenological description of void growth via frustum-like dislocation structure is also proposed. As for the shape effect, the simulation results reveal that the initial void geometry has substantial impact on the stress response during void growth, especially for a specimen with a relatively large initial porosity. During void coalescence, the void shape combination is found more influential than the intervoid ligament distance (ILD) on the strength and damage development. The critical stress to trigger the dislocation emission is found in line with the Lubarda model. The dislocation density calculated from simulation is qualitatively consistent with the experimental measurement. For densely-arranged pores, the diamond-array-pore sample exhibits a superior stress response at the same initial porosity. The onset of plasticity is investigated for differently-structured nanoporous samples, which could shed light on the novel designs of nanoporous structure with enhanced structural integrity. Main contributions of this work can be summarized as follows. First, we show that the shape and the arrangement of nanovoids have a great impact on the mechanical performance of nanoporous metals. Secondly, the “relative displacement” is employed to visualize atom movement during interfacial debonding and dislocation formation. Thirdly, the “shear impossibility” debate is preliminarily settled. Fourthly, the Lubarda model for critical stress to trigger dislocation emission is extended to the case of nanoporous geometry.
Author/Creators:
Cui, Yi
Title:
Computational Studies on Structure and Mechanical Properties of Carbides in HCCIs
Description:
High Chromium Cast Irons (HCCIs) are widely used in mineral processing, slurry pumping and manufacturing processes, where high resistance to erosion and synergetic erosion-corrosion is required. The excellent performance of HCCIs results from their microstructure, which consists of hard carbides (mainly in hypereutectic HCCI) and ferrous matrix (austenite or martensite ). The matrix helps absorb impact force and enhance toughness of the material, while the hard carbides play a crucial role in withstanding the wearing stress. Due to different processing treatments and chemical compositions, the morphology and mechanical properties of carbides can vary significantly, which affects HCCIs' wear performance. In this study, the effect of core-shell structured carbides on HCCIs' wear performance and the effect of Cr content on M7C3 carbides' mechanical properties are studied by different simulation methods. C++ programming based MSDM method is used to study and optimize the core-shell structured carbides, which have been proved beneficial to HCCIs' wear resistance. By measuring local properties, including Young’s modulus and electron work functions, and conducting first-principles calculations for individual phases, HCCIs' erosion-corrosion performance in slurry are better understood. At last, the correlation between Young's modulus and electron work function is explained by first-principles calculation from an electronic view.
Author/Creators:
Cui, Juan
Title:
Quantitative Characterization of Dynamic Sitting Control during Continuous Multi-Directional Perturbations
Description:
Facilitating trunk stability is one of the most important objectives in human balance control. This is especially evident in individuals with spinal cord injury (SCI) who are typically not able to control seated balance on their own. As a consequence of their injury, they often suffer under a reduction of strength and control of their trunk muscles and, hence, under reduced independence during daily activities. One of the top priorities for individuals with SCI is therefore to improve their trunk control and, consequently, quality of life. To enhance existing therapies and/or develop bio-inspired assistive technologies that can facilitate dynamic trunk stability in these individuals, a more comprehensive, quantitative understanding of the neuromechanical mechanisms of dynamic sitting control in non-disabled individuals is needed. The objective of this study was therefore twofold: (1) to quantify the effect of varying levels of seat instability as well as of visual information elimination on postural efficiency during continuous, multi-directional perturbations using a wobble board paradigm; and (2) to quantify the temporal and spatial relationship between muscle activity and wobble board motion during the perturbations. 15 non-disabled individuals were asked to sit on a wobble board inducing continuous, multi-directional perturbations and maintain an upright sitting posture as closely as possible. Five different hemispheres with decreasing diameter were attached to the bottom of the wobble board to induce five different levels of seat instability. Sitting tasks were performed with eyes open and eyes closed. A motion capture system was used to collect trunk and pelvis kinematics as well as those of the wobble board. The activity of fourteen major superficial trunk and upper leg muscles was recorded via an electromyography system. Wobble board kinematics and muscle electromyography were then used to characterize trunk control and stability during dynamic sitting. In a first step, posturographic analyses in time and frequency domain were performed to assess postural proficiency. In a second step, cross-correlation analysis was applied to identify temporal and spatial determinants of muscle activation and, hence, reactive trunk control for the wobble board task. For the posturographic analyses, our findings revealed that time-domain measures were generally increased and frequency-domain measures generally decreased when task difficulty was increased. Similarly, time-domain measures were generally increased and frequency-domain measures generally decreased when visual information was eliminated. For the cross-correlation analysis, our findings indicate the existence of a relation between phasic muscle activation/deactivation and wobble board motion, which increased in intensity with higher levels of seat instability, irrespective of eye condition. Spatial features revealed that the rectus abdominis, erector spinae, biceps femoris, and rectus femoris muscles were correlated with anterior-posterior wobble board displacement, whereas the external oblique muscles were correlated with medial-lateral wobble board displacement. Moreover, temporal features revealed that, regardless of base, eye condition, and wobble board displacement direction, muscle activation/deactivation preceded the wobble board displacement. On the one hand, the posturographic findings suggest that, by increasing seat instability or eliminating vision, the control effort increases and the degree of stability decreases. On the other hand, the cross-correlation results indicate that the dynamic balancing task is accomplished with significant contributions from active control mechanisms that originate from the central nervous system (CNS). More specifically, the spatial characterization suggests that the CNS modulates the phasic muscle activity levels to break the upcoming wobble board motion. For sagittal plane motion, this is done by increasing the effective stiffness between the human body and the wobble board. For frontal plane motion, further work is needed to confirm or dispute the use of such CNS-based stiffness control strategy. The temporal characterization suggests that the CNS takes advantage of the velocity information of the body and/or wobble board to generate the required motor command in advance of an imminent displacement. These interpretations demonstrate that the performed work has made significant contributions to our fundamental understanding of human balance control in general and of wobble board stabilization more specifically. The gained knowledge may be beneficial for enhancing existing therapies and quantitative assessments, but also for developing bio-inspired assistive technologies that can facilitate trunk stability in individuals with SCI.
Author/Creators:
Gholibeigian, Fatemeh
Title:
Mercury and methylmercury in snowpacks, snowmelt, and tailings ponds of the Athabasca Oil Sands Region, Alberta, Canada
Description:
The Alberta Oil Sands Region (AOSR) is the third largest proven oil reserve in the world and one of Canada’s major economic drivers. Industrialized extraction of this resource has resulted in the release of contaminants from various sources, such as stack emissions, volatilization and leakage of chemicals from tailings ponds, increased erosion due to land disturbance, and blowing dust from landscape disturbance, road activity, and open-pit mines. Among the contaminants released to the environment from industrial activities are organic pollutants, such as polycyclic aromatic hydrocarbons and naphthenic acids, sulphur dioxide and nitrogenous oxide species, secondary organic aerosols and the 13 elements (Ag, Ar, Be, Cd, Cr, Cu, Hg, Ni, Pb, Se, Sb, Tl, Zn) considered priority pollutants elements under the U.S. Environmental Protection Agency. Mercury (Hg) is also a contaminant of concern in the AOSR, especially methylmercury (MeHg), which is a potent vertebrate neurotoxin that biomagnifies through food webs to concentrations that may be of concern to consumers including humans. Total Hg (THg: all forms of Hg in a sample) concentrations downstream of the AOSR and THg and MeHg loadings in snowpacks have also been found to be elevated; however, sources of this Hg are not known. In this thesis, I: 1) quantify THg and MeHg concentrations in four AOSR tailings ponds varying in composition, age, surface area, and volume; and 2) determine if MeHg is actively produced in AOSR snowpacks and melted snow, or associated with the particles deposited there. I show that surface and sub-surface water concentrations of THg (unfiltered 0.30 ± 0.14 ng/L; filtered 0.26 ± 0.12 ng/L) and MeHg (unfiltered 0.15 ± 0.20 ng/L; filtered 0.08 ± 0.11 ng/L) were low in the four tailings ponds, with the highest concentrations observed in the oldest pond. In mature fine tailings that settle out in the ponds, concentrations of THg (58.6 ± 50.2 ng/g) and MeHg (0.23 ± 0.16 ng/g) were also low, with the highest concentrations also observed in the oldest pond. Overall, these ponds are not likely a major source of THg or MeHg to downstream freshwater ecosystems into which they slowly leak, though further assessment of the source of the MeHg in the oldest pond should be pursued. To determine if MeHg is produced within snowpacks and/or melted snow of the AOSR, I used Hg stable isotope incubation experiments at four sites located varying distances from the major industrial developments. Results from these experiments demonstrated that the potential rate of MeHg production was low in snowpacks (km = 0.001–0.004 d-1) and non-detectable in melted snow, except at one site (km = 0.0007 d-1), and that in situ production is therefore unlikely an important source of MeHg to AOSR snowpacks. Concentrations of MeHg on particles (pMeHg) in snowpacks increased linearly with distance from the upgraders (R2 = 0.71, p <0.0001); however, snowpack total particle and pMeHg loadings decreased exponentially over this same distance (R2 = 0.49, p = 0.0002; R2 = 0.56, p <0.0001). Thus, at near-field sites, total MeHg loadings in snowpacks were high due to high particle loadings, even though particles originating from industrial activities are not MeHg rich compared to those originating from natural sources at distant sites. More research is required to identify snowpack particle sources.
Author/Creators:
Willis, Chelsea E.
Title:
Nosema ceranae: A sweet surprise? Investigating the viability and infectivity of the honey bee (Apis mellifera L.) parasite N. ceranae
Description:
Nosema disease is a prominent malady among adult honey bees (Apis mellifera L.), caused by the microsporidian parasites Nosema apis and N. ceranae. The biology of N. apis is well understood, as this parasite was first described over a century ago. Unlike N. apis, N. ceranae is an emerging parasite of the honey bee, and consequently, we do not yet understand how long spores of this parasite survive in honey bee colonies, or how they are transmitted among bees. We investigated the viability and infectivity of the infectious (spore) stage of N. ceranae in substrates associated with honey bee colonies after exposure to 20, 33, -12, and -20°C, over various time intervals. Spores stored in honey and sugar syrup survived considerably longer than those stored in water or on wax comb, with low loss in viability at freezing temperatures for up to one year. Honey and sugar syrup appear to provide a reservoir of viable and infective spores that can initiate or perpetuate N. ceranae infections in honey bee colonies. This study provides information that may help enhance current management recommendations for apiculturalists.
Author/Creators:
MacInnis, Courtney I
Title:
The Effects of Liposome Treatment on Red Blood Cells during Hypothermic Storage
Description:
Red blood cells (RBCs) are the most commonly used components in cell therapy and their transfusion save millions of lives every year. These benefits were only achieved through advances in blood banking storage techniques that guarantee an available supply of blood to support medical emergencies and treatments. Although use of additive solutions extends storage length of RBC units, the quality of stored RBCs progressively decreases during hypothermic storage giving rise to a series of biochemical and biomechanical changes, collectively known as “hypothermic storage lesion” (HSL). Since membrane integrity is an important predictor of RBC survival and function and constitutes one of the targets of HSL, this research has focused on the use of liposomes, synthetic lipid vesicles, to mitigate RBC membrane injury during hypothermic storage. This thesis tested the hypothesis that liposome treatment of stored RBCs would improve in vitro membrane quality resulting in reduced in vitro production of proinflammatory and procoagulant markers and a safe transfusion product in an anemic rat model. Investigations were conducted on several levels, from assessing baseline differences between rat and human RBCs and the effect of blood component manufacturing on rat RBCs to transfusion of liposome treated-RBCs in a rat model and evaluation of the impact of liposome treatment on hypothermic storage lesion and consequent effects on hemorheologic, immune and coagulatory profile of human blood banked RBCs. The work presented here has established a processing method more suitable for use in animal models of transfusion evaluating HSL as well as demonstrated the effect of DOPC liposomes on rat RBC hemorheology and showed for the first time the in vivo effects of transfusing liposome-treated RBCs in an animal model. Furthermore, it has verified the benefit of liposome treatment in human RBCs by fully characterizing the effects of DOPC liposomes on membrane and metabolic in vitro quality parameters in human RBCs during hypothermic storage. Finally, it has produced novel information about the potential effects of DOPC-treated RBCs and supernatants on the immune response using different cell types, a comprehensive cytokine panel and endothelial activation markers, relevant to current understanding of in vivo inflammatory effects. This thesis has advanced the knowledge of transfusion medicine and biopreservation by offering important insights into the effects of liposome treatment as a tool to mitigate HSL in RBCs that might lead to novel research efforts and unveil the potential of liposomes for biopreservation of other clinically relevant cell types.
Author/Creators:
Da Silveira Cavalcante, Luciana
Title:
Three Essays on Beef Genomics: Economic and Environmental Impacts
Description:
The successful diffusion of new agricultural biotechnologies depends on widespread producer acceptance and uptake. The assessment of the key factors that can influence producer decision making is fundamental to the understanding of the rate of uptake, the attainable rate of potential benefits and the effectiveness of different measures that can stimulate the diffusion of these innovations. This dissertation examines three related aspects of cow-calf producer decision making with regards to the uptake of genomic selection for feed efficiency in beef cattle production in Canada. Improvements in feed efficiency can have significant economic and environmental impacts on beef cattle production through the reductions in feed costs and greenhouse gas emissions. Specifically, the following objectives are addressed: (i) the evaluation of the factors affecting cow-calf producer willingness to pay (WTP) for genomically improved feed efficient bulls (ii) the assessment of how supply chain linkages can influence cow-calf producer decision making (iii) the assessment of environmental outcomes from different decisions made by cow-calf producers and the extent to which the opportunity to obtain additional revenue from these environmental externalities can influence these decisions. In the first paper, cow-calf producers’ private valuation of genomic information on feed efficiency in their bull purchase decision is assessed. The analysis is situated in a multi-trait context that accounted for both conventional and genomic breeding information and cow-calf producer heterogeneity due to attitudes and farm practices. The results indicated that willingness to pay (WTP) for genomic information is positive; cow-calf producer valuation of conventional breeding technologies is relatively higher. The results further showed evidence of heterogeneity in cow-calf producer preferences according to characteristics such as risk perceptions, calf retention practices and familiarity with genomics. The results of the second paper highlight the potential supply chain issues that can impact the widespread diffusion of the innovation. From the stylized industry framework outlined, the allocation of benefits from the genomic selection for feed efficiency is skewed towards feedlot operators who typically do not incur the cost of bull purchases in fragmented systems. The results suggest that in the absence of a mechanism that rewards cow-calf producers for the additional cost associated with the genomic bull, the diffusion of the innovation is likely to be slow. The results of the third paper show that breeding for feed efficient cattle is associated with positive environmental outcomes across the three agroecological zones considered. The simulation analysis showed that these environmental benefits differ spatially and are highest when the selection for feed efficiency is combined with limits on stocking rates. While the participation in a carbon offset scheme is an additional source of revenue which can possibly change cow-calf producer incentives, the results show that revenue from the offset scheme is inadequate given the low level of emissions per farm and the examined price of carbon. Overall, the empirical results of this study suggest that genomic selection for feed efficiency can improve the economic and environmental performance of the Canadian beef cattle industry. The potential supply chain bottlenecks and the spatial heterogeneity in cow-calf production must however be accounted for in the design of mechanisms to stimulate cow-calf producer uptake.
Author/Creators:
Boaitey,Albert
Title:
Tracking the Common Ground in Dialogues: Cultural and Genre Effects
Description:
A socio-cognitive approach to language assumes language is multimodal, embodied in general cognition, and modulated by contextual cues (van Dijk, 2014). Research on situation models confirms that language is processed multimodally and experiences top-down influence from pre-existing knowledge in memory (Kurby & Zacks, 2015; Therriault & Rinck, 2012; Zwaan, 2014; 2015). However, most of this research has been done using written narratives and therefore does not account for contextual cues that may arise in spoken dialogue contexts. Furthermore, context and memory have been shown to modulate how participants interact with the common ground, which is always present in spoken dialogues (Colston in Kecskes & Mey, 2008; Gibbs & Colston in Giora & Haugh, 2017; Duran et al., 2011; Gann & Barr, 2014; Fukumura, 2014). The first goal of the present study was to investigate the contextual influence of spoken dialogue and genre on event-indexing factors (protagonists/objects, time, setting, cause/effect relationships, goals/plans of the protagonists) and to see if new factors were elicited in spoken dialogue. As participants incorporate these factors into their situation models, difference in individual pre-existing knowledge would result in unique representations for each participant and therefore modulate overlaps in shared knowledge. Thus, the second goal was to investigate how differences in pre-existing cultural knowledge affected participants’ ability to establish common ground with each other. This was done by manipulating the linguistic and cultural background of the participants included in the study. The present study analysed videos of 10 minute of spoken dialogues between 72 undergraduate students at the University of Alberta (36 pairs). Participants were either Canadian native English speakers (NS) or non-native international students (NN). They were divided into pairs of NS-NS, NS-NN, and NN-NN. Furthermore, participants were divided into either gossip or summarizing task conditions. In the gossip conditions participants received the prompt “Discuss Donald Trump”. In the summarizing condition they read two different articles about Donald Trump and summarized them to each other. The 6 resulting conditions (e.g. Gossip: NS-NS) were counterbalanced by genre and pairing, with 6 pairs in each condition. Videos were coded for instances of event-indexing factors or other factors produced with the same frequency; feedback cues indicating successful or successful establishment of common ground; and pragmatic structures or sequences indicating a reliance on the common ground. Analysis was done using logistic regression models. The results suggest speaker attitude is as important as previously established event-indexing variables in dialogues. Speaker-attitude, setting, and cause/effect relationships occurred significantly more in gossip conditions, whereas goals/plans occurred significantly more in summarising conditions. Both NN and NS gave more feedback indicating understanding when speaking to a NS than NN. NS were more successful at establishing referents in conversations. Congruent pairs (NN with NN-NN; NS with NS-NS) were more successful at reducing the amount of linguistic information required to convey a concept. In conclusion, this study shows the genre of discourse modulates the information tracked and cultural background of interlocutors modulates how that information is understood in a discourse.
Author/Creators:
Morrow, Keely P
Title:
A Histological Analysis of the Hadrosaurid Dental Battery
Description:
The first histological study of an entire hadrosaurid dental battery provides a better understanding of this complex structure. The hadrosaurid dental battery is composed of interlocking, vertically stacked columns of teeth that form a complex grinding surface. The dental battery was previously considered to be a solid, cemented structure based on superficial examination of intact batteries and thin sections of isolated teeth. This first description of the dental battery using thin sections through the entire structure refutes the model of a single, fused mass of teeth. These thin sections confirm the presence of periodontal ligament connections between all teeth, underscoring its dynamic nature. The serial thin sections across an adult dental battery also revealed signs of gradual and possibly ontogenetic tooth migration. These signs include the extensive remodeling of the alveolar septa and the anteroposterior displacement of successive generations of teeth. The four most posterior tooth families migrated posteriorly whereas the remaining tooth families had a progressively more pronounced anterior trajectory. This migration is pronounced enough in some areas to cause extensive resorption of neighbouring teeth. Thin sections through a dental battery of a perinatal specimen reveal that all of the alveolar septa are angled anteriorly, which suggests that extensive and unidirectional tooth migration begins early in ontogeny and that any additional migration happens later in ontogeny. Although the mechanisms behind tooth migration in the hadrosaurid dental battery require further investigation, addition of tooth families during growth and opposition of forces during palinal mastication may have had a strong influence. Focusing on the individual hadrosaurid teeth shows that they exhibit a highly specialized arrangement of hard tissues to allow each tooth to be ground down completely. Histological thin sections of teeth from the hadrosaurid dentary and the mammalian ever-growing incisor reveal surprising similarities in morphology and hard tissue organization. These similarities include the shift of the cemento-enamel junction to form a cutting edge along the occlusal surface. Similar to modern rodents and lagomorphs, the wear of the softer dentine and cementum, continuous eruption, and plugging the pulp cavity allowed hadrosaurid teeth to form a continuously replenished wear surface. The mammalian ever-growing incisor thus serves as an unexpectedly accurate model for dentinogenesis in the hadrosaurid tooth. The mammalian ever-growing incisor is a valuable extant analogue for understanding the perceived complexity of the hadrosaurid tooth than previously proposed models. Using this model, a heterochronic shift in dental ontogeny was inferred between neonatal and adult hadrosaurids as dentinogenesis is inferred to function at a different rate in the adult hadrosaurid. A new subtype of primary dentine, crestal dentine, was also revealed during this study. Crestal dentine has an increased hardness based on its chemical composition and tubular structure, which allows it to functionally replace the enamel that is lost in older functional tooth generations of a tooth family.
Author/Creators:
Bramble, Katherine K
Title:
Robert Lepage's Stravinsky: Rhyming Imagery on Stage
Description:
Québécois Director/Writer/Performer/Filmmaker Robert Lepage is internationally recognized for his striking multimedia productions and transformative mise-en-scène. This thesis specifically explores Lepage’s staging of two Igor Stravinsky operas: The Rake’s Progress (2007), and The Nightingale and Other Short Fables (2009). This is not a musicological study, rather it is an analysis of the mise-en-scène Lepage devised for these productions. Lepage employs a specific method of seeking commonalities between disparate stage imagery, and orchestrating radical transformations of the stage picture around those reoccurring elements, using them as reference points for his audience. These reference points are to his stage picture what homonyms and rhymes are to poetry; they change meaning based on context, and resonate with the spectator on more than one level. Using tools described in Erving Goffman’s Frame Analysis (1976), and Marvin Carlson’s The Haunted Stage (2003), I approach Lepage’s mise-en-scène as a layering of intersecting frames. Secondly, a close reading and analysis approaches the mise-en-scène of Lepage’s The Rake’s Progress (2007) as a form of adaptation, drawing from Linda Hutcheon’s A Theory of Adaptation (2013). Finally, I examine The Nightingale (2009) with a libretto based on the Hans Christian Andersen tale of the same name, on its emulation of 19th century chinoiserie, using principles from Edward Said’s Orientalisim (1978).
Author/Creators:
Nearey, Brendan P.J.
Title:
Group Trip Planning Queries in Spatial Databases
Description:
Trip planning queries are considered an important part of Location Based Services. As the first part of our research, we investigated Sequenced Group Trip PLanning Queries (SGTP) queries. Given a set of source locations and destinations for a group of n users, and a sequence of Categories of Interests (COIs) that the group is interested to visit altogether, a SGTP query returns for each user, the route from his/her source location to his/her destination such that all users go through the same Points of Interests (POIs), while minimizing the group total travel distance. As the second phase of our research, we assumed that users are interested to visit a POI belonging to the predefined COI altogether with the goal of minimizing the total detour distance towards group’s preferred paths. In the third phase of this research, we investigated a combination of trip planning and path nearest neighbor queries, which we refere to as “Best-Compromise In-Route Nearest Neighbor”. We investigated the problem where a user, traveling on his/her preferred path, needs to visit one (of many) POI while minimizing his/her total travel distance and also minimizing the detour distance incurred to reach the chosen POI. Finally, we studied the k-CPQs in road networks. Given two sets of nodes P and Q on a road network, a k-Closest Pairs Query (k-CPQ) finds the pairs from P × Q which have the k smallest network distances. Although this problem has been well studied in the Euclidean and metric spaces, this is the first time it is being investigated in the more realistic case of road networks.
Author/Creators:
Ahmadi, Elham
Title:
The Disruption of iASPP Binding to PP-1cα via Small Molecules Sourced from Marine Organisms
Description:
Protein Phosphatase-1 (PP-1c) is a broad specificity Ser/Thr phosphatase catalytic subunit responsible for a variety protein dephosphorylation events in eukaryotic cells. The specificity and activity of PP-1c is largely controlled by over 200 regulatory subunits, including the Apoptotic Stimulating Proteins of p53 (ASPP). ASPP1 and ASPP2 are two members of the ASPP family that are responsible for promoting the pro-apoptotic activity of the tumour suppressor p53, while an inhibitory ASPP (termed iASPP) is responsible for inhibiting p53 activity. PP-1c, iASPP, and p53 form a protein complex which promotes the dephosphorylation of p53, and in turn, inhibits its pro-apoptotic activity. iASPP is over-expressed in two thirds of all human cancers containing wild-type p53. The purpose of this Masters thesis project was to identify small molecules that may disrupt iASPP•PP-1c binding as a necessary first step to hindering dephosphorylation of p53 by PP-1c. The principal hypothesis was that the iASPP•PP-1c protein complex could be targeted for disruption with bioactive marine compounds. Such compounds may have the potential to be novel anti-cancer drugs in cancer types that over-express iASPP. This project was determined to be feasible because preliminary data by Dr. Tamara Arnold demonstrated that two marine compounds, Sokotrasterol Sulfate and Suvanine, disrupt iASPP•PP-1cα binding. The results of this thesis show that iASPP•PP-1c binding can be targeted for disruption. Through the use of a novel protein-protein binding assay, I identified two novel iASPP disruptors, called Halistanol Sulfate and Coscinamide B. The potency and specificity of Halistanol Sulfate, Sokotrasterol Sulfate, and Suvanine were further characterized and all three demonstrated specificity towards the ASPP family vs. other PP-1c regulatory subunits, such as TIMAP (TGF-β-Inhibited Membrane-Associated Protein). Additionally, Suvanine preferentially disrupted iASPP binding to PP-1cα vs. ASPP2; therefore, Suvanine is the most promising candidate for specific iASPP•PP-1c disruption. Finally, during this investigation for PP-1c disruptors, I was also able to identify marine compounds that inhibit PP-1c activity. I discovered an abundant new source of the small molecule, Motuporin, as well, I discovered a novel bromophenol compound that potently inhibits the activity of PP-1c.
Author/Creators:
McLellan, Melissa M.
Title:
Pressurized fluid extraction of anthocyanins from cranberry pomace and its use in bioactive food coatings for almonds
Description:
About 94% of total cranberry production is mainly used by the juice industry, generating cranberry pomace, which is a rich source of anthocyanins. Pressurized fluids have been used to extract phytochemicals from different by-products. Such phytochemicals can be used in edible food coatings to prevent food deterioration reactions hence consumer rejection. The main objective of this study was to extract anthocyanins and total phenolics from cranberry pomace with pressurized fluids and use the extracts obtained in pectin and pectin+beeswax based coatings to prevent deterioration reactions of almonds. Pressurized fluid extractions were performed in a high pressure reactor using different solvents (water, ethanol, water+30-70%ethanol and water+5%citric acid) at 120–160ºC and 50–200 bar. Pressurized ethanol extractions were also performed at 50 bar and 40-100ºC. Spectrophotometric methods were used to determine total anthocyanin content (mg cyanidin 3-glucoside equivalent), total phenolic content (mg gallic acid equivalent) and antioxidant activity (µmol trolox equivalent). Individual anthocyanins were also quantified by HPLC-UV. Then, edible coatings, pectin based and pectin+beeswax based, were developed with the addition of cranberry extracts at ratios of 1:1 and 1:3 pectin:extract (w/w) and applied to almonds using the spraying method. Coated and uncoated almonds were stored at 40ºC and 50%RH for 90 days. Incipient rancidity of the coated and uncoated almonds was analyzed using a spectrophotometric method and almond fatty acid composition was analyzed using GC. High anthocyanin content was extracted using pressurized ethanol at 50 bar and 60-120ºC with an extraction range of 3.89-4.21 mgCy3GE/g d.w. with no significant difference between those conditions. High concentrations of cyanidin 3-arabinoside and peonidin 3-galactoside were obtained after all extractions. High total phenolic contents were obtained using pressurized ethanol30%+water at 140ºC (42.48±7.82 mg GAE/g d.w.) and 160ºC (41.19±2.07 mg GAE/g d.w.). The use of pressurized ethanol resulted in better Pearson correlation value (P=0.84) between total anthocyanins and antioxidant capacity compared to pressurized water (P=-0.35). This last value suggests possible deterioration of anthocyanins into other phenolic compounds like phologlucinaldehyde and 4-hydroxybenzoic acid. The use of bioactive coatings on almonds had no significant impact in neither the fatty acid composition nor the incipient rancidity after storage at 40ºC and 50% RH for 90 days. Also, no significant difference was observed in incipient rancidity with a peroxide value range of 2.5-4.5 mEq/kg oil. This thesis has shown that pressurized fluid extraction is an environmentally friendly alternative to extract anthocyanins and total phenolics from cranberry pomace and that the selectivity of anthocyanins with ethanol is higher compared to water and ethanol+water mixtures. Such extracts could be used as natural antioxidants or natural colorants. Also, the development and application of pectin and pectin+beeswax coating with cranberry extract was achieved. These bioactive coatings could be applied to nuts, fruits and candies.
Author/Creators:
Rodriguez Martinez, Eduardo N
Title:
High Performance liquid Chromatography Analysis of Nucleosides and Nucleobases in Mouse Plasma and Xenopus oocytes
Description:
In humans, there are three members of the cation-coupled concentrative nucleoside transporter CNT (SLC28) family, hCNT1-3: hCNT1 is selective for pyrimidine nucleosides but also transports adenosine, hCNT2 transports purine nucleosides and uridine, and hCNT3 transports both pyrimidine and purine nucleosides. hCNT1/2 transport nucleosides using the transmembrane Na+ electrochemical gradient, while hCNT3 is both Na+- and H+-coupled. By producing recombinant hCNT3 in Xenopus laevis oocytes, I used radiochemical high performance liquid chromatography (HPLC) analysis to investigate the metabolic fate of transported radiolabelled [3H] and [14C] pyrimidine and purine nucleosides inside cells. My findings suggest that transported nucleosides in oocytes after 30 minute of incubation are generally subject to minimal intracellular metabolism (uridine 7%, cytidine 0%, thymidine 0%, inosine 16% and guanosine 0%). The exception was adenosine, for which only 49% remained unmetabolized. I also used radiochemical HPLC analysis to study mechanisms by which adenosine functions as an atypical low Km, low Vmax permeant of pyrimidine nucleoside-selective hCNT1. Oocytes producing recombinant hCNT1 were pre-loaded with [3H]uridine, after which efflux of accumulated radioactivity was measured in transport medium alone, or in the presence of extracellular non-radiolabelled adenosine or uridine. The results found that hCNT1-mediated [3H]-efflux was stimulated by extracellular uridine, but inhibited by extracellular adenosine, with > 95% of the radioactivity exiting cells being unmetabolized radiolabelled uridine. This suggests that the low Vmax for adenosine transport by hCNT1 is a consequence of low transmembrane mobility of the hCNT1/adenosine complex. Humans also possess four members of the equilibrative nucleoside transporter ENT (SLC29) family, hENT1-4. hENT1 and hENT2 function to transport both nucleosides and nucleobases into and out of cells, but their relative contributions to nucleoside and nucleobase homeostasis and, in particular, to adenosine signaling via purinoreceptors, are not known. My second project addressed this question by using HPLC to compare plasma nucleoside and nucleobase concentrations in wild-type, mENT1-, mENT2- and mENT1/mENT2-knockout (KO) mice. Results from these studies demonstrated the importance of ENT1 relative to ENT2 in determining plasma adenosine concentrations, indicating a modest role of both transporters in inosine homeostasis, and suggested that neither is a major participant in handling of nucleobases.
Author/Creators:
Altaweraqi, Reema A
Title:
Effect of Grazing on Litter Decomposition and Extracellular Enzyme Activity across Agro-climatic Subregions in Alberta
Description:
Grasslands cover approximately 40% of the Earth’s terrestrial surface and provide a wide range of ecologically and economically important services such as forage production, carbon (C) and nitrogen (N) storage, and wildlife habitat. Livestock grazing is a ubiquitous use of grasslands around the globe; however, the direct and indirect effects of grazing on ecosystem processes including C and nutrient cycling, are still overlooked. To better understand how livestock grazing and associated shifts in plant community compositions affect ecosystem function, we studied decomposition of litter of different grass species and extracellular enzyme activity (EEA) over 18-months using litterbags, placed inside and outside of long-term grazing exclosures at 15 sites across three grassland subregions, including the Central Parkland, Foothills Fescue and Mixedgrass Prairie. Overall, livestock grazing increased litter decomposition rates and EEAs in litter samples, though this response varied among subregions and individual enzymes; decomposition was most rapid in the Foothills Fescue followed by the Parkland and Mixedgrass subregions. While grazing enhanced enzymes activities regulating C cycling, it decreased those associated with N and P cycling decomposing litter. No effects of grazing on soil EEAs were detected. Litter types also altered litter decomposition rates and EEAs regardless of subregion or grazing effects. P. pratensis had particularly high decomposition rates and EEAs, especially in the Foothills, and a similar pattern existed for B. gracilis in the Mixedgrass, suggesting increases in these grazing tolerant species may alter biogeochemical cycling, and therefore C accumulation. Results from this study suggest that grazing could play a critical role in regulating litter decomposition and C cycling in the northern temperate grassland.
Author/Creators:
Chuan, Xiaozhu
Title:
Bio-based nanocomposites from poultry feather keratin
Description:
Chicken feathers are byproduct of poultry industries and except some minor low end application, they are generally dumped into landfills. An effort has been made to utilize this by-product by transforming them into nano-reinforced bioplastics which is not only a solution to feather waste disposal but also an attractive option to develop high performance nano-structured biomaterials from renewable and sustainable bioresource. To obtain bionanomaterials from these feathers, in-situ nanodispersions and modifications of feathers were carried out to obtain bionanocomposite (BNC) powders suitable for processing by compression molding technique. The obtained BNC powders were then simultaneously plasticized, cross-linked and processing conditions were optimized for film formation. Nano-fillers such as layered silicates and cellulose nanocrystals were used as nano-reinforcements for enhancing the material properties of the obtained films. The obtained bio-nanocomposite films were characterized by various analytical techniques. The thermal properties were analyzed by thermogravimetric analysis (TGA) and Differential Scanning Calorimetry (DSC). The thermomechanical properties of the samples were also investigated by Dynamic Mechanical Analysis (DMA) over a temperature range of -50 °C to 150 °C. The glass transition temperatures for CNC reinforcements were found to be higher (225 to 242 ºC) than MMT (199 to 221 ºC) reinforcement. Slight increase in glass transition temperatures has been observed with increase in MMT content from 1% to 5% while bio-nanocomposites with 1% and 10% CNC content showed improvements in glass transition temperatures. Structural analysis was carried out by wide angle X-ray diffraction (WAXD) and transmission electron microscopy (TEM). The arrangement of MMT in the bio-nanocomposite matrix ranged from intercalated to exfoliated at low content of the MMT (1% and 3%). However WAXD and TEM analysis displayed aggregations at higher concentration (10%) of both MMT and CNC nanoparticles. The mechanical properties of biomaterials were investigated by Universal Testing Machine (autograph AGS-X Shimadzu, Canada) instrument. The two nanoparticles had different effect on tensile strength and elongation at break of the nanocomposites. MMT enhanced the tensile strength while CNCs incorporated samples showed higher percent elongation. The preliminary investigations on biodegradability of these biomaterials were also carried out using soil burial tests. The onset of degradation was found to be soil moisture dependent with ~ 25-30% weight loss within 10 days.
Author/Creators:
Kaur, Manpreet
Title:
Lithosphere Removal in the Central Andes: Reconciling Seismic Images and Elevation History
Description:
The central Andes (18° - 26°S) is an active Cordilleran orogen, formed through the subduction of the Nazca oceanic plate beneath the South American continent. Despite significant tectonic crustal shortening and thickening (60 -70 km), deep seismic imaging indicates a thin to absent mantle lithosphere beneath the central Andean plateau (Altiplano-Puna plateau). In order to explain this as well as regional geological observations (e.g. widespread mafic volcanism, and along-strike timing variations in uplift across the plateau), lithosphere removal has been proposed to have occurred within the central Andean system within the last 20 Ma. Conditions within Cordilleran systems, such as the central Andes, can produce density inversions (i.e. roots) within the plateau mantle lithosphere, including: changing pressure-temperature conditions induced by subduction, crustal tectonic shortening, and cyclical magmatic processes. The presence of gravitationally unstable mantle lithosphere drives its removal. Motivated by these observations, the present study uses thermal-mechanically coupled geodynamic models in order to study gravitational removal of single and multiple dense roots within an active subduction zone setting, representative of the central Andes. Both lithosphere removal via large-scale coherent delamination and localized Rayleigh-Taylor (RT)-type instabilities are investigated. Emphasis is placed on i) the dynamics and timing of removal events, ii) the topographic response to lithosphere removal, and iii) the predicted seismic velocity structures generated as lithosphere removal proceeds. In general, subduction-induced flow aids the removal process, perturbing the lithosphere and entraining the foundering material to remove it from the system. For the modelled lithospheric structure, delamination causes mantle lithosphere to coherently peel away from the overlying crust towards the subducting oceanic slab. The numerical modelling experiments show this delamination occurs within 5 – 12 m.y., resulting in 0.5 – 0.7 km isostatic uplift, with removal proceeding faster for decreased root density and increased mantle lithosphere strength (i.e. dehydrated conditions). In comparison, RT-type instabilities of greater density and decreased strength are more readily destabilized. Mantle lithosphere is locally removed within 2 – 12 m.y., and the root’s down-going trajectory is largely dependent on its relative position to the trench and the rate at which is descends. Note that lithosphere removal of a single RT instability results in local uplift of 0.5 km, whereas destabilization of multiple roots positioned across the extent of the plateau causes regional uplift of 1 – 1.2 km. This study shows that present-day lithosphere structure across the Altiplano-Puna plateau can be reproduced through episodes of gravitationally driven lithosphere removal. Overall, for both removal mechanisms (i.e. delamination and Rayleigh-Taylor-type instabilities), predicted seismic velocity structures are able to reconcile previously identified upper mantle velocity anomalies to a certain degree, supporting the idea that low velocity zones beneath the central Andean plateau represent high temperature areas of thinned mantle lithosphere. However, regardless of the manner of removal, the resulting surface uplift is limited to ~1 km, suggesting the modern Altiplano-Puna plateau topography is likely not solely linked to removal-induced isostatic and dynamic elevation changes.
Author/Creators:
Henderson, Olivia A.
Title:
Paleodepositional Environments and Stratigraphic Framework for the Lower Cretaceous Bluesky Formation and Related Strata in the Peace River Oil Sands Deposit of Alberta
Description:
The Early Cretaceous Bluesky Formation in the Peace River oil sands area of west-central Alberta, Canada hosts significant bitumen resources. This work is part of an ongoing endeavour by researchers and practitioners in academia and industry to develop paleodepositional and sequence stratigraphic models for the Bluesky Formation and related deposits of the underlying Gething Formation and the overlying Wilrich Member. In this thesis, sedimentological, ichnological, and micropaleontological datasets are acquired from core, and paleodepositional interpretations for the formations of interest are made. Sediments in the upper Gething Formation preserve remnants of brackish bay and paralic swamp and marsh deposits. The Bluesky Formation is described by thirteen facies. Recurring succession of these facies are grouped into six facies associations representing both proximal and distal marginal marine environments and include: 1) fluvial- to wave-influenced distributary channel and terminal mouth bars, 2) mixed-influence proximal delta fronts, 3) wave- and storm-influenced, proximal to distal delta fronts, 4) wave-influenced delta fronts and shoreface environments, 5) lower bay shoreface to distal bay settings, and 6) tidal flats. Wilrich Member successions are represented by a Glossifungites-demarcated discontinuity and marine mudstones. These depositional environments are linked spatially and temporally by important sequence stratigraphic surfaces that formed during a series of regressive and transgressive events. Bluesky successions were deposited at fourth- or fifth-order scales and formed within the longer duration third-order phase of sea-level rise in the Early Cretaceous. Importantly, relative sea-level rise was episodic. During stillstand episodes of transgression, Bluesky progradation ensued. Regressive surfaces of marine and fluvial erosion mark these retrogradational episodes. Cross-section analysis reveals an apparent backstepping of the Bluesky Formation in the region as transgression proceeded. These progradational pulses were interrupted by high-order flooding events that are correlatable across the study area. Complete inundation of the study area by the Boreal Sea is marked by a third-order major flooding surface and is represented by transgressive Wilrich Member deposits. In addition to building a depositional model for the study area and understanding the paleoenvironmental evolution of the area in terms of sequence stratigraphic events, a number of complimentary studies are conducted. One particular study focuses on a facies that preserves world-class specimens of stacked Rosselia, which formed when burrowing tracemakers vertically re-adjusted their positions in the sediment following depositional events. Where present, these traces help to refine paleoenvironmental interpretations and can be used as proxies for assessing the magnitude and frequency of depositional events. The use of Rosselia illustrates a method of evaluating sedimentation events within a brief temporal window, one lying beyond the resolution of more traditional dating methods. The second study considers palynomorphs and microfossils preserved in cored intervals. The micropaleontological assemblages are calibrated with sedimentological and ichnological features to fine-tune depositional interpretations. Foraminifera and microfossils provide semi-quantitative paleosalinity ranges for the various depositional environments preserved in cored successions. Dinoflagellate cysts are used to identify important stratigraphic boundaries between Gething, Bluesky, and Wilrich sediments and to constrain the age of the Bluesky Formation to Early Aptian, an age older than previously recorded.
Author/Creators:
Campbell, Sean, G
Title:
Exploring Undergraduate Students’ Perceptions of Teaching and Satisfaction in Blended Learning
Description:
This study investigates the influence of teaching attributes on student satisfaction as perceived by university students enrolled in a blended learning course when the learning context is predominantly a campus-based experience. It merges theory from educational psychology and marketing research to explore the psychometric functioning of a new teaching quality scale, the Blended Learning Questionnaire (BLQ). Secondary data from 178 undergraduate, Faculty of Education students using the BLQ instrument was used to investigate their perceptions of the teaching delivered in both formats, face to face and online, of a blended learning course. Results of exploratory factor analysis indicated that student-focused methods of teaching feedback are possible to measure in the relatively new educational context of blended learning, and that several key aspects of that context – the clarity of goals, quality of teaching strategies, and appropriate assessment methods - are salient to students. A multiple regression analysis using the recovered teaching factors predicted a total of 58% of student course satisfaction, with teaching in the face to face format predicting the majority of satisfaction (49%). However, when students’ importance ratings about the teaching experience were considered in the analysis, less course satisfaction was explained. In borrowing from the service quality literature, the BLQ was used to capture the discrepancies between students’ perceptions of the teaching (P) and their relative importance to satisfaction (I). A multiple regression analysis of the gap scores (P – I) predicted 22% less course satisfaction than students’ perceptions approach alone, with the majority of satisfaction again predicted by teaching experienced in the face to face setting (36%). While the perceptions approach evidenced greater predictive power, the information gained by including importance weightings allowed for the identification of service gaps which provides greater diagnostic power for blended learning educators than a single perceptions measure. In this study, efforts were primarily identified as best spent on improvements in specific aspects of online teaching delivery. Identifying areas of teaching that have the highest performance gap scores (i.e., high importance score and low perception score) is a step towards identifying which teaching qualities, or combinations, are most influential to the student experience. These findings support a growing trend in higher education research that links quality teaching to measures of student satisfaction so as to gather evidence of the effectiveness of teaching practices and curriculum change. As there has been little systematic quantitative research to date that has addressed key aspects of teaching quality across online and face to face experiences, this study represents an early exploration of this gap and contribution to the blended learning literature.
Author/Creators:
Dragon, Karon L.
Title:
Increasing Calcaneal Plantar Flexion as a Method to Improve Weight Bearing Leg Dorsiflexion
Description:
Previous research on foot and ankle mechanics has shown that weight bearing leg dorsiflexion range of motion is positively correlated to calcaneal plantar flexion. The gastrocnemius muscle promotes while the plantar aponeurosis and plantar intrinsic muscles restrict calcaneal plantar flexion. Thus, reducing plantar aponeurosis and plantar intrinsic muscle tension while increasing gastrocnemius strength may improve weight bearing leg dorsiflexion range of motion. Twenty-seven participants with poor (< 25°) leg dorsiflexion were enrolled and randomly assigned to one of two six-week intervention groups. Group 1 (n = 14) performed self-massage and stretching of the plantar aponeurosis and plantar intrinsic muscles three days per week. Group 2 (n = 13) performed the same self-massage and stretching in addition to a modified glute-ham-gastroc raise exercise. The weight bearing lunge, the standard assessment for leg dorsiflexion, was assessed before and after the intervention. Additionally, force platforms and three-dimensional motion analysis were used to examine lower extremity kinetics and kinematics during a partial squat exercise, with ankle net joint moments, peak leg dorsiflexion and calcaneal plantar flexion being the primary movements of interest. In the weight bearing lunge, Group 1 improved their leg dorsiflexion by 3.7 ± 2.9° (Effect Size (ES) = 1.16) in the left and 4.2 ± 3.2° (ES = 1.25) in the right. Group 2 experienced greater increases in the left of 4.9 ± 4.4° (ES = 1.80) and 6.4 ± 3.7° for the right (ES = 1.51). In the partial squat, leg dorsiflexion increased -0.6 ± 3.2° for the left (ES = 0.15) and -1.0 ± 2.6° for the right (ES = 0.24) in Group 1, and -2.3 ± 4.2° for the left (ES = 0.55) and -2.1 ± 3.2° for the right (ES = 0.59) in Group 2. There were small increases in calcaneal plantar flexion where Group 1 increased -0.7 ± 2.6° in the left (ES = 0.25) and -0.2 ± 2.7° in the right (ES = 0.08), whereas Group 2 increased -0.3 ± 3.2° in the left (ES = 0.15) and -2.7 ± 6.2° in the right (ES = 0.64). These results suggest that plantar aponeurosis and plantar intrinsic muscle self-massage and stretching in combination with modified glute-ham-gastroc raise exercise could be an alternative to calf stretching to improve weight bearing leg dorsiflexion range of motion.
Author/Creators:
vonGaza, Gabriella L
Title:
Records of atmospheric mercury deposition and post-depositional mobility in peat permafrost archives from central and northern Yukon, Canada
Description:
Environmental archives provide a feasible means for studying the biogeochemical cycling of heavy metals including mercury (Hg). Although many temperate peat bogs have been successfully used to reconstruct natural and anthropogenic atmospheric Hg deposition fluxes, northern circumpolar permafrost peatlands are largely understudied in similar research. Consequently, substantial gaps remain in our understanding of past atmospheric Hg deposition fluxes and present peatland Hg inventories from northern environments. This thesis presents a critical investigation of using peat permafrost archives for quantifying natural and anthropogenic atmospheric Hg deposition fluxes. The first objective of this research was to develop an effective protocol for collecting and processing peat permafrost samples for inorganic geochemical analyses. Refined techniques were established for accurately measuring bulk density and homogenizing well-preserved fibrous peat. This method was then used to reconstruct historic atmospheric Hg deposition from a permafrost peat plateau near Dawson, Yukon, with the aim of resolving a deposition peak corresponding to extensive Klondike gold mining during the late 19th and early 20th centuries. The results revealed an unexpectedly early increase in anthropogenic Hg deposition, which was ultimately interpreted to result from post-depositional Hg mobility within the seasonally thawed active layer. This discovery implies that peat permafrost archives may not provide reliable high-resolution records of atmospheric Hg deposition. However, a subsequent study involving seven Holocene (10,000-year old) peat plateaus from central and northern Yukon reveal that millennial-scale atmospherically deposited Hg concentrations and fluxes were consistently low; ~20.7 ± 9.8 ngg-1 and ~0.51 ± 0.39 μgm-2y-1, respectively. These results were used to demonstrate how peat permafrost Hg inventories could be estimated at the local scale. Provided additional empirical data from sites spanning the northern circumpolar region, future studies may use the same approach to estimate cryosol Hg stocks at regional to global scales and assess the potential vulnerability of Hg release from thawing permafrost with continued climate warming.
Author/Creators:
Bandara, Sasiri
Title:
Methods to Create Equivalent Models for Power System Studies
Description:
Adequate modeling of all of the power system components including generators, transmission lines, loads, and neighboring power systems is essential for power system analysis. With nowadays large interconnected power systems, it is common practice to represent only the study system with high accuracy and use simplified equivalent models for the neighboring systems. The type of the required equivalent depends on the type of the study they are intended for. For example, power flow studies require equivalent models at fundamental frequency, whereas high-frequency transient studies require frequency dependent network equivalents (FDNEs). This thesis research investigates methods to construct three equivalent models for power system studies. They are (1) measurement-based equivalent external system model for online steady-state power system analysis, (2) single-port and multi-port frequency dependent external network model for electromagnetic transient analysis and (3) measurement-based equivalent π circuit parameters estimation of parallel transmission lines. For the first subject, this research has developed an online network equivalencing method based on synchronized phasor measurement data. The phasor data is used to estimate and update a multi-port Thevenin equivalent circuit continuously. An important issue in implementing this method is that the external network should remain constant during the identification process. Therefore, a disturbance detection method is utilized to determine if noticeable changes have happened in the external system. For the second subject, a heuristic optimization method is used to find a FDNE from the frequency response data of an external system. An equivalent circuit consisting parallel branches with positive elements is considered and the problem is formulated as an over-determined nonlinear problem. A proper coding scheme is used and different optimization methods are applied and compared to choose the best one. For the multi-port case, a model consisting of all-positive and all-negative stable branches is considered to be able to fit the non-diagonal elements of the admittance matrix. The non-diagonal elements are fitted one by one and then the diagonal elements are fitted similar to a single-port problem. For the third subject, synchronized phasor data are utilized to find the π-circuit parameters of a newly constructed transmission line in parallel with an existing transmission line. The method utilizes the induced voltages as the excitation source and uses measurement data collected at both ends of the two parallel lines to estimate the unknown parameters. Different connections of the conductors of the new line are considered for collecting the required data. The parameter estimation problem is divided into two linear sub-problems which are solved using the least-squares method.
Author/Creators:
Moghimi Haji, Moosa
Title:
Methods and Implementations of Historically Accurate Game Design for First Person Shooter Video Games
Description:
Video games have become a common and often consumed medium to portray and to learn about history. Building on the work done by historians to understand historical accuracy on film, I design and built a first person shooter (FPS) video game that could be considered historically accurate by the historical community. The game centres on Operation Deadstick, an opening mission of the Normandy landings on D-Day, 6 June 1944. To portray accurately the historical content I designed the game using a Mechanics-Dynamics-Aesthetics (MDA) game design framework. This framework guided the implementation of the historical elements in all aspects of the game’s design including its cosmetics, gameplay mechanics, and themes. I evaluated the game by examining its historical content through these same elements. Although the game was incomplete, I believe it represents a positive first step towards the design of historically accurate interactive content.
Author/Creators:
Holmes, David M
Title:
SUN GLARE: NETWORK CHARACTERIZATION AND SAFETY EFFECTS
Description:
Visibility is one of the basic requirements for safe driving. Any type of vision obstruction can interfere with the driver’s ability to operate a vehicle and thus poses a significant risk to road traffic safety. In addition to widely investigated adverse weather conditions such as rain, fog, and snow, which can reduce visibility, bright sunny days may also bring challenges to safe driving due to the phenomenon of sun glare. Although much evidence has been found to support that sun glare can highly impair one’s visual performance, there are significant gaps in the knowledge and methodology dedicated to examining and quantifying the sole effects of sun glare on road safety. The overall objective of this thesis is to gain a better understanding of the risks on the road network posed by sun glare and evaluate its safety effects in the city of Edmonton. To achieve this objective, a two-stage analysis was conducted. The first stage developed a methodology to model sun glare occurrence for the road network in the city, aiming to identify when and where a driver would be exposed to the risk of sun glare by considering different factors associated with the sun’s position and road geographical conditions. Consequently, potential sun glare time windows were demarcated for each month over a typical year and corresponding glare prone locations were identified and plotted in a series of visualization maps, which can provide a reference to the public for identifying locations where sun glare is most prominent in the city of Edmonton. After identifying the glare prone locations, the safety risks at those locations during sun glare periods were assessed in the second stage. By contrasting the number of collisions during glare and non-glare conditions, this second stage aimed to quantify the sole effects of sun glare on road collisions. A case-control design method was used to control for potential confounding factors related to weather condition, collision time/location, and travel direction. To test the significance of the differences in collision numbers, several statistical techniques were employed and included: chi-square test of independence, configural frequency analysis, and the Wilcoxon signed rank test. Ultimately, three major findings were concluded from the results of the collision analysis. First, sun glare was found to significantly contribute to collision occurrence, especially at road intersections. Quantitative assessments showed that collisions were expected to increase by about 30% under the condition of sun glare. Second, sun glare effects during mornings and evenings were observed to be especially worse in the months of spring and fall. Also, most of the daytimes in January, November, and December, traffic safety in the southbound direction was significantly affected by sun glare. Lastly, certain collision maneuver types were over-presented during sun glare. It was found that the collisions due to signal violations and failing to yield to pedestrians and cyclist were over-presented at intersections. At mid-block locations, the proportions of collisions due to improper turning and lane changes were observed to be significantly higher. Overall, the approaches proposed and developed in this thesis provide a new and innovative method to quantify the effects of sun glare on road safety. By linking sun glare exposure modeling with a thorough glare related collision assessment, this research helps to provide additional insights about the extent by which sun glare affects road safety. The findings from this thesis can be used to assist in alleviating the risks associated with sun glare in the planning and designing of future roads.
Author/Creators:
Sun, Danyang

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