title: Examining the reproducibility of the observed cardiorespiratory fitness response to standardized training

contributor:
Gurd, Brendon
Kinesiology and Health Studies

subject:
Cardiorespiratory fitness
Reproducibility
Individual response

abstract: There is considerable heterogeneity in observed cardiorespiratory fitness (CRF) responses to standardized training.  Evidence from twin and family training studies demonstrates a strong link between an individual’s genetics and the observed CRF response to standardized training, supporting the hypothesis that true individual differences in training responsiveness exist.  If true individual differences do exist, it would be reasonable to speculate that the observed CRF response to an initial period of training would predict the observed response to an identical period of training separated by an adequate washout period.  Thus, the current training study exposed a group of 14 recreationally active males to the same four-week treadmill running training program twice, separated by a three-month washout period.  Baseline CRF at training periods one (PRE1) and two (PRE2) were very strongly correlated (r = 0.94, p < 0.01) and were not significantly different at the group level (p = 0.056).  A significant main effect of time (PRE vs. POST) (p < 0.001) and period (training period one vs. training period two) (p < 0.001) were observed for CRF (training period one: +4.04 ± 2.29 mL/kg/min, training period two: +2.83 ± 2.74 mL/kg/min) with no significant interaction effect (p = 0.13).  At the individual level, the observed CRF response in period one did not predict the response in training period two (r = 0.4, p = 0.15).  The results from this study suggest that either true individual differences in training responsiveness do not exist or that random within-subject variability and technical error mask the ability to detect individual differences.  Future training studies should examine potential combinations of behavioural/environmental factors, which may influence the observed CRF response to standardized training.

abstract: M.Sc.


title: Gay By The Bay: Feeling Queer, Feeling Newfoundland

contributor:
Murray, Laura
Cultural Studies

rights: Queen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canada

rights: ProQuest PhD and Master's Theses International Dissemination Agreement

rights: Intellectual Property Guidelines at Queen's University

rights: This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.

subject:
rural queer studies
rural studies
queer studies
Newfoundland and Labrador
Newfoundland
queer
rural
queer migration
metronormativity
homonormativity
narrative
personal narrative

abstract:
While growing up in rural Newfoundland, I often felt that my identities as a rural Newfoundlander and a queer person were in conflict. Inspired by my own experiences and those of my loved ones, I began this research with the primary goal of documenting the experiences of rural Newfoundland’s queer youth in such a way that carefully maintained the autonomy of my participants and their voices. However, as the study progressed it became clear that my broad exploration was trying to answer one question: given the difficult – often painful and traumatic – experiences of queer youth in rural Newfoundland, could our identities as rural Newfoundlanders and queer people easily coexist?

This thesis attempts to document the experiences of queer rural Newfoundlanders while asking why and if the identities of queer and rural Newfoundlander are irreconcilable. This work is based upon narratives and experiences I have collected from seven queer youth who have lived or are currently residing on Newfoundland’s rural west coast. I have coupled my participant’s narratives with my own in recognition that this research has been a profoundly personal act of introspection for me. I analyze our experiences in reference to structures of feeling, a concept coined by Marxist Raymond Williams to describe one way that culture and power interact.

My findings suggest that queer youth, from diverse backgrounds and of diverse identities, have extreme difficulty reconciling their identity as a rural Newfoundlander with their queer identity. My findings also suggest that many queer youths in rural Newfoundland are as strongly affected by homonormativity and metronormativity as they are by cis-heterosexism and queerphobia. Finally, this research has shown that queer youth in rural Newfoundland, and likely elsewhere, would benefit from readily visible queerer forms of queerness.

abstract: M.A.


title: Moisture Uptake and Loss of Geosynthetic Clay Liners from a Silty Sand Subgrade Under Isothermal Hydration and Thermal Cycles

contributor:
Rowe, Kerry
Brachman, Richard
Civil Engineering

rights: Attribution-NonCommercial-NoDerivs 3.0 United States

subject:
Geosynthetic clay liner
Hydration
Thermal cycles
silty sand
isothermal

abstract:
Geosynthetic clay liner (GCL) performance is said to rely on adequate hydration from the subgrade which is controlled by factors such as the properties of the GCL, subgrade and permeant, and their exposure to solar radiation. Much research has been conducted on this topic, however, this thesis examines several significant knowledge gaps and, in particular, the performance of partially hydrated GCLs when permeated with synthetic municipal solid waste leachate. In addition, the components affecting moisture retention or loss of GCLs when subjected to simulated thermal cycles are examined for GCLs that were deconstructed by cutting of the needle-punched fibres to allow each component to be studied in isolation.

The findings from column hydration tests performed on GCLs placed on a silty sand subgrade of varying density, compaction conditioning time, and grain size distribution due to silt aggregation are reported. For the isothermal tests, the columns were stored at 25±4°C for four weeks. For cyclic tests, the column airspace was subjected to thermal cycles up to 60°C for the fifth week.  Results suggest that silt aggregation can inhibit moisture uptake if not sufficiently broken down by compaction and a GCL that appeared to retain moisture on a typical subgrade lost moisture when placed on a subgrade characterized by high silt aggregation, low density, and long conditioning times.  A GCL with fine-grained bentonite that initially lost moisture under thermal cycles also began to retain moisture when the bentonite was ground to a powdered form.
The swell index and cation exchange capacity of the bentonite and the hydraulic conductivity of various GCLs (in terms of bentonite granularity, geotextile type, and construction) were obtained after prehydration at 5% and 16% subgrade water contents. The lowest hydraulic conductivity was for a thermally treated GCL with powdered bentonite (4.5 x 10-11 to 8.4 x 10-12 m/s) and the highest was for a non-thermally treated GCL with coarse-grained bentonite (6.0 x 10-08 to 5.1 x 10-10 m/s). The significance of subgrade water content to GCL performance was mostly due to cation exchange and varied with the type of GCL and permeant.

abstract: M.A.Sc.


title: Advancing Security Services for Cloud Applications

contributor:
Zulkernine, Mohammad
Computing

subject:
Cloud applications
Security
Security as a Service
Software as a Service
Program analysis
Data analytics
Security Monitoring
Vulnerability Scanning
Cloud Computing

abstract:
With cloud computing taking roots, Software as a Service (SaaS) is transforming the future of Information Technology (IT). SaaS is a modern pervasive software delivery model in the Cloud in which software providers host applications and provide them to consumers over the Internet. The Cloud brings operational and analytical applications together to empower software innovation. SaaS has become indispensable to the advancement of applications spanning different domains such as business, banking, and health. Although the glory of SaaS grows in popularity, an important question remains: how secure are cloud SaaS applications? Cloud SaaS applications are highly accessible, and the vast amount of sensitive data they manipulate makes them an attractive target by attackers. Nevertheless, software providers and consumers overlook critical security measures as they move to the Cloud, obliterating any gains made.
In this thesis, we address these concerns and aim to advance security services for cloud SaaS applications. Cloud Security as a Service (SecaaS) model expands the horizon to deliver security solutions over the Internet. Motivated by the rise of the SecaaS model, this research proposes a platform introducing Information Flow Control as a Service (IFCaaS) notion. The platform embeds robust and effective IFC-based security services in different phases of the software development lifecycle (SDLC) to govern end-to-end protection of cloud applications. Further, the platform is augmented by the Cloud capabilities to provide efficient and scalable security services. Data breaches due to security vulnerabilities, insecure APIs and interfaces as well as insecure computations and unauthorized access are prevalent security issues to cloud applications. Hence, this research expands on targeting two different types of applications in the Cloud: operational and analytical. It presents two different security services and builds a framework for each service. They aim at mitigating the aforesaid security issues regarding each application type. Extensive evaluation of the proposed frameworks is conducted over benchmark applications in real-world settings. The experimental results reveal that the presented frameworks provide robust, effective, and yet efficient protection for cloud applications against prevalent security breaches. They offer significant improvement in terms of detection accuracy, performance, scalability, and resource consumption.

abstract: PhD


title: The Effects of PMMA Surface Chemistry and Extracellular Traps on Macrophages, Lens Epithelial Cells and the Wound Healing Response

contributor:
Wells, Laura
Chemical Engineering

subject:
neutrophil extracellular traps
macrophages
lens epithelial cells
wound healing
poly(methyl methacrylate)

abstract:
Posterior capsule opacification (PCO) is a condition that affects 20-40% of patients that
undergo cataract lens replacement surgery. The design of the replacement intraocular lens (IOL)
(for instance material, shape, and surface chemistry) is thought to be one of the main
contributing factors to its development. Following the implantation of a biomaterial, there is a
response by the immune system, activating cells and the release of various factors. The
neutrophil is one of the first immune cells to respond and consequently has an effect on local
cells and downstream immune cells. Also, neutrophils release a meshwork of DNA and proteins
termed neutrophil extracellular traps (NETs). NETs are present during the inflammatory
response and can affect downstream immune cells (i.e. macrophages) and the local cells.
Therefore, it is hypothesized that the lens surface chemistry and the immune response of the
neutrophils affect the behaviour of lens epithelial cells (LECs) and macrophages in the wound
healing response.
In this research, NETs were isolated from an HL60 cell line and used to investigate their
effect on macrophages (activated THP1 cells) and LECs in vitro. Cell viability and behaviour of
these cell types were assessed to determine the effects that NETs have on local and immune cells
involved in PCO and the wound healing response. Poly(methyl methacrylate) (PMMA) disks
were functionalized with amine or carboxyl surface groups to explore how the surface chemistry
can affect LEC behaviour and viability in vitro. Lastly, in vivo analysis of functionalized
PMMA beads investigated the healing response and neutrophil presence to different surface
chemistries.
When THP1 cells were incubated on tissue cultured polystyrene (TCPS) pre-treated with
NETs, the NETs increased monocyte differentiation and TNF-α production when paired with
iii
activation with phorbol 13-myrstate 12-acetate (PMA) but there was no significant increase in
THP1 cells differentiation when they were incubated on NETs only. It was also found that there
were paracrine effects on the activated macrophages, leading to increased cell activation when
THP1 cells were seeded onto TCPS at a higher cell density. When LEC were incubated on
TCPS with pre-adsorbed NETs, the NETs decreased LEC viability but, interestingly, increased
the production of alpha smooth muscle actin (α-SMA), a marker of epithelial to mesenchymal
transition.
When LEC were incubated on PMMA, the PMMA surface chemistry altered the viability
of LECs and α-SMA production, with increased viability and α-SMA expression on aminated
PMMA. When PMMA beads were injected subcutaneously into C57BL/6J mice, there was
increased neutrophil presence and vessel formation 7 days after injection as well as differences in
these two measures surrounding the aminated and carboxylated PMMA. Neutrophil presence
was increased surrounding PMMA-COOH and vessel structure formation was increased
surrounding PMMA-NH2 at 1 day and 7 days after injection.

abstract: M.A.Sc.


title: Succeeding in Mobile Application Markets (From Development Point of View)

contributor:
Zou, Ying
Electrical and Computer Engineering

subject:
App Store
Empirical Study
Software Maintenance
User-Review
Mobile Software Engineering
Mobile Application

abstract: Mobile application (app) markets, such as Google Play Store, are immensely competitive for app developers. Receiving high star-ratings and achieving higher ranks are two important elements of success in the market. Therefore, developers continuously enhance their apps to survive and succeed in the competitive market of mobile apps. We investigate various artifacts, such as users' mobile devices and users' feedback, to identify the factors that are statistically significantly related to star-ratings and ranks. First, we determine app metrics, such as user-interface complexity, and device metrics, such as screen size, that share a significant relationship with star-ratings. Hence, developers would be able to prioritize their testing efforts with respect to certain devices. Second, we identify the topics of user-reviews (i.e.,~users' feedback) that are statistically significantly related to star-ratings. Therefore, developers can narrow down their activities to the user-reviews that are significantly related to star-ratings. Third, we propose a solution for mapping user-reviews (from Google Play Store) to issue reports (from GitHub). The proposed approach achieves a precision of $79\%$. Fourth, we identify the metrics of issue reports prioritization, such as issue report title, that share a significant relationship with star-ratings. Finally, we determine the rank trends in the market. We investigate the most important factors that are statistically significantly related to the changes in the ranks, such as release latency. The outcome of this thesis helps app developers to be more successful in the market. Having the knowledge of the factors that are statistically significantly related to star-ratings and ranks helps developers to make wiser decisions to develop a successful app.

abstract: PhD


title: Game-Engine Based Rockfall Modelling: Testing and Application of a New Rockfall Simulation Tool

contributor: Geological Sciences and Geological Engineering

subject:
Rockfall
LiDAR
Remote Sensing
Geohazard

abstract:
Rockfall presents an ongoing challenge to the safe operation of transportation infrastructure across Canada, creating hazardous conditions which can result in damage to roads and railways, as well as loss of life. Conventional rockfall risk assessment frameworks involve the determination of several pieces of information relevant to hazard management including where rockfalls might come from, how frequently they will fall, and how large the falls will be. Another important piece of information is the likelihood that a given fall will reach the road or railway. One method of estimating this likelihood is the use of rockfall runout programs which simulate the 3D trajectories of volumes of falling rock. The focus of this research is the development and testing of a new rockfall simulation workflow which uses the Unity3D game engine and other complimentary 3D modelling software packages.

	The simulation method developed has been applied to two different rockfall field studies from the literature, one in Ehime Japan, and one in the Port Hills region of New Zealand. Rockfall runout information collected at these sites including translational and rotational velocity, and deposition location, has been used to test the ability of our technique to simulate rockfall trajectories which are realistic compared to rockfall events on real slopes. A parametric investigation into the various inputs necessary to setup a basic rockfall simulation was also completed in order to identify any key sensitivities in the model.

	The workflow necessary to produce 3D rockfall simulations using Unity3D is outlined. The technique is capable of simulating the trajectories of multiple moving fragments at once and supports the use of high-resolution 3D geometry extracted from remote sensing datasets. Using this workflow five fragmental rockfall events from our field study sites in South-Central, British Columbia were simulated. The results of this work demonstrate the capability our rockfall simulation tool to model complex rockfall scenarios using high-resolution (<10 cm) terrestrial laser scanning inputs.

abstract: M.A.Sc.


title: Three-Dimensional Simulation of Water Quality in a Wastewater Stabilization Pond

contributor:
Boegman, Leon
Civil Engineering

subject:
Wastewater stabilization pond
Delft3D
Water quality modelling
3D model

abstract:
Wastewater stabilization ponds (WSP) are effective secondary or tertiary treatment systems, however simple water quality models that assume the ponds behave as either completely stirred tank reactors (CSTR) or plug flow systems are commonly used in design. These models consider a WPS to be a homogeneous or a one-dimensional system, respectively, and critically neglect spatial variability in hydrodynamics that leads to poor characterization of variability in residence time, biogeochemistry and removal efficiency. Despite these shortcomings, CSTR and plug-flow models are still used for pond design because of their simplicity. This thesis explores the application of fully three-dimensional (3D) computational models capable of being applied to develop better design guidelines that will assist municipalities in meeting effluent regulations.
Some 3D models that have been applied to WSPs, neglect complex biochemical reactions and are limited to use first order decay removal. To date, no calibrated water quality model that can simulate complex biochemical processes and is coupled with a calibrated 3D hydrodynamic model has been applied to a WSP. The present study focuses on development of a 3D water quality model of a secondary facultative pond coupled with a 3D hydrodynamic model. The calibrated water quality model was also coupled with CSTR (0D) and plug flow (1D) hydrodynamic models to show the disadvantages of these simplified and widespread assumptions in WSP modelling.
The 3D numerical model reproduced the observed WSP effluent nutrient, dissolved oxygen, pH, and phytoplankton seasonal dynamics and quantitatively reproduced nutrient removal (5-7% error). The model was extended to investigate the effect of physical changes in pond design (inlet location, baffle configuration, wind sheltering, depth) on performance, which revealed that increasing the depth of the pond and constructing wind sheltering improved pond performance. Removing baffles had no impact on nutrient removal efficiency and relocating the inlet to the surface reduced the pond efficiency. The 0D and 1D models over-predicted effluent concentration of all substances, with the exception of pH and dissolved oxygen since the nutrients were typically sequestered near the bottom of the pond during stratified conditions. Mixing events from wind and buoyant inflows caused the model predictions to converge with consistent vertical distributions. The numerical results from this thesis provide a detailed view of biogeochemical processes in WSPs and suggest that future designs should consider the influence of 3D hydrodynamics on nutrient removal and pond performance.

abstract: M.A.Sc.


title: Bodies as Risky Resources: The Japanese Identification Systems as Surveillance, Population Control and Colonial Violence in Occupied Northeast China

contributor:
Lyon, David
Sociology

subject:
Identification System
Surveillance Technology
ID Card
Fingerprint
Colonialism
Violence
Rationalization
Japan
China
Labour Control
National Security
Unit 731
Koseki
Policing

abstract:
This dissertation investigates the emergence and transformation of national identification (ID) systems in modern Japan. I focus on colonial techniques of the ID systems in Northeast China under Japanese occupation in 1931-1945. Colonial ID techniques paid particular attention to identifying individuals and tracking their movements. Most prominently, fingerprinting, the forerunner of biometrics, was employed. Fingerprinted ID cards in occupied China were used for two primary purposes: pre-empting potential rebellion among the local Chinese, and mobilizing them as cheap labour power. Biometric ID systems became a powerful means of population control, which helped the Japanese to classify the Chinese as “desirable” or “undesirable”, and reduce them to resources, not subjects, of the Empire. As a result, the colonized population experienced the ID systems as part of overall, targeted inequality and violence against the Chinese. The worst cases of Japanese surveillance may be the Chinese dissidents who were sent to Japanese Army Unit 731, a secret facility for biochemical warfare. They were used as living ingredients for bacterial experiments and human dissection. Under colonial surveillance, Chinese bodies were classified according to their best use by the Imperial political economy and its cruel, racist science.
My theoretical frame critically engages with biopower (Foucault), the state of exception (Agamben), and necropolitics (Mbembe) in sequence, to analyze nation-state and colonialism as a simultaneous process of modernization. Methodologically, I combined a genealogical approach, institutional ethnography and semi-structured, in-depth interviews, to learn about Chinese experiences with Japanese colonial surveillance, in my three-month fieldwork in Northeast China in 2016.
This project makes three major contributions to Surveillance Studies and society at large. First, I demonstrate how earlier colonial ID techniques are passed on to postwar Japan, and what are the implications for electronic mass surveillance systems globally proliferated today. Second, surveillance experiences in the former colonial zones have been marginalized, and little explored, so my research helps fill in this gap in our knowledge. Lastly, my ultimate goal is to contribute to bringing ethical considerations to ID systems both for individual liberty and dignity, and to constructing more respectful and peaceful relationships among global communities.

abstract: PhD


title: The English State Lottery-Loan and the Origins of Modern Public Finance in the Atlantic World, 1694 - 1826

contributor:
Collins, Jeffrey
den Otter, Sandra
History

subject:
England
Lottery-Loan
Public Finance History
Financial Revolution
Colonial America
Atlantic World
Eighteenth-Century
State Formation

abstract: The 170 English state lottery-loans held from 1694 to 1826 were a key method of modern longterm debt-based public finance, utilized as an important emergency contingency in times of war. This dissertation examines the neglected contribution of longterm lottery-loans to Anglo- American public finance in the long eighteenth-century. The implementation of the lottery-loan program in England had substantial political, economic, and legal consequences in domestic England, as well as in colonial America. The significant role played by the English state lottery- loans in the financial revolution has been overlooked. This thesis establishes state lotteries as integral to the post-1688 financial revolution and re-evaluates major claims of the revolution thesis in regards to public finance innovation and state stability. By the end of the eighteenth century English and American public finance would firmly embrace the liberal fiscal principles that supported public debt as an integral part of the modern state.

abstract: PhD


title: Issues in International Macroeconomics And Finance: A Time-Series Analysis

contributor:
Head, Allen
Gregory, Allan
Economics

subject:
Empirical Macroeconomics
FCVAR
Bayesian Estimation

abstract:
This thesis consists of two main parts. The first part is composed of two essays. The first essay addresses the common movements of employment growth within and across 12 countries in the European Monetary Union after the formation of the currency union. A Bayesian dynamic factor model is used to analyse fluctuations in European employment cycles and the co-movement of sectoral employment growth across industries and countries, so as to derive the sources of these fluctuations. The findings suggest that these co-movements did not tend to increase after the introduction of the euro. The results for sectoral employment growth indicate that the idiosyncratic factor accounts for a large share of the fluctuations in employment growth.  For the variance that is not due to the idiosyncratic factor, the common-European factor accounts for the largest share of these fluctuations.

The second essay uses a vector autoregressive model to estimate the effects of each country's country-specific mark-up and technology shocks. The model separately identifies each country's mark-up and technology shocks by imposing restrictions on the sign of each country's impulse responses. The study finds that these shocks are equally important,  quantitatively, for explaining the fluctuations in the relevant macroeconomic variables.

The second part presents the final essay, which examines applications of a recently developed fractionally cointegrated vector autoregressive model to commodity spot and futures prices. This essay, co-authored with Morten Ørregaard Nielsen, Paresh K. Narayan, and Ke Xu, models and forecasts commodity spot and futures prices using FCVAR models to accommodate fractional integration. The findings illustrate that, on average, the fractional model generates higher profits compares to non-fractional cointegrated VAR model, especially when analysing futures markets.

abstract: PhD


title: Age-related differences in passive trunk stiffness, seated spine postures, and muscle recruitment patterns

contributor:
Dumas, Genevieve
Kinesiology and Health Studies

subject:
Biomechanics
Ergonomics
Aging
Tissue Material Properties
Electromyography
Sitting

abstract:
Introduction:  Age is associated with changes in tissue stiffness as well as higher muscle activity and an increase in the prevalence of low back pain. With increased worker age globally, and with the increased incidence of occupational sitting, it is important to understand how trunk stiffness changes with age and how this trunk stiffness is affected by sitting in older, sedentary workers.
Methods: 37 women (aged 20-65 years) participated in the current study. Age was classified two ways: Chronological Age and Fitness Age (based on performance in fitness battery). Trunk stiffness was measured using a passive trunk flexion apparatus described in literature. Participants sat for 60 minutes at a computer workstation throughout which, at 10-minute intervals, seated spine posture, perceived low back discomfort, and muscle activity (EMG) for 6 bilateral trunk muscles were recorded. Correlations were used to assess relationships between age and stiffness, perceived discomfort, posture, and EMG variables; and ANOVAs were used to detect differences in stiffness, posture, and muscle activation between age and discomfort groups.
Results: Trunk stiffness increased significantly with age, with the strongest of these relationships measured with Fitness Age (r = 0.517, p = 0.003). Age was not related to posture or to the magnitude of movement displayed while sitting; however, trunk stiffness was negatively correlated with seated spine motion (r = -0.435, p = 0.023). There was no relationship between age or discomfort with muscle activation patters.
Conclusions: Age showed a positive relationship with stiffness, which was stronger when examining Fitness Age than Chronological Age.  This suggests that age-related research could be improved using measures of fitness rather than age (based on year of birth). Furthermore, the decreased movement while sitting with elevated spine stiffness suggests that altered tissue material properties could affect the manner in which people perform seated work, leaving them more susceptible to the effects of static postures including reduced blood flow, nerve impingement, and associated discomfort or injuries. Further investigation is warranted to find an easy way to monitor trunk material properties in the workplace in order to control for their effect on worker health.

abstract: PhD


title: Neuromodulatory and metaplastic regulation of long-term synaptic plasticity in the primary visual cortex of adult rats.

contributor:
Dringenberg, Hans
Neuroscience Studies

subject:
LTP
Synaptic Plasticity
Metaplasticity
Learning
Memory
Neuromodulation

abstract:
Synaptic plasticity in the neocortex of mammals is influenced by various neuromodulators and metaplasticity mechanisms. These regulatory processes allow synaptic networks to operate and adjust to various behavioral states and the constantly changing inputs from the sensory environment. The neurochemical milieu created by neuromodulators is an important regulator of synaptic plasticity at the time of induction, while metaplastic-processes regulate neuronal networks based on their history of activity. This thesis investigated the effects of the neurochemical milieu and past experiences (learning) on long-term potentiation (LTP) of synapses in vivo in the primary visual cortex (V1) of adult rats. Initial experiments revealed that the application of the neuromodulator serotonin (5-HT) in V1 was ineffective at altering LTP. However, LTP was facilitated in the presence of a 5-HT1A-receptor antagonist. Interestingly, in juvenile rats, the same antagonist exerted the opposite effect (i.e., inhibited LTP), indicating an age-specific role of 5-HT1A receptors in the gating of V1 synaptic plasticity. Next we examined the role of visual experience (visual discrimination training) on LTP in the adult V1. Rats trained to discriminate visual cues in a Y-shaped water maze apparatus subsequently exhibited enhanced LTP compared to naive or control (visually untrained) rats. The facilitation of LTP in visually trained rats was reversed by an antagonist of GluN2B subunits of the N-methyl-D-aspartate receptor (NMDAR) in V1. Consequently, we examined potential changes in NMDAR functioning in rats trained in the visual discrimination task. Patch clamp recordings of principal neurons in V1 revealed that behavioral training enhanced GluN2B-mediated NMDAR conductance. Finally, we examined the behavioral consequences of blocking GluN2B receptors during visual discrimination training, using a sequential task that involved two distinct rounds of training (involving different sets of visual cues). Results of these experiments showed that systemic GluN2B antagonism during the second round of visual training impaired task
acquisition relative to controls. Together, the experiments in this thesis highlight the importance of neuromodulation and metaplasticity in V1 for the gating of LTP, one of the principal mechanisms of learning and memory storage in the cortex of mammalian species.

abstract: PhD


title: Methods for Improving Ability to Investigate the Effectiveness of Non-Invasive Treatment Strategies for Medial Knee OA

contributor:
Deluzio, Kevin
Mechanical and Materials Engineering

subject:
Biomechanics
Osteoarthritis
Knee
Brace
Motion Capture
Gait
Biofeedback

abstract:
Osteoarthritis (OA) is the most common form of arthritis, occurring frequently in the medial compartment of the knee. As the onset and progression of medial knee OA has been associated with abnormal and excessive loading of the joint, non-invasive treatment options often focus on joint load reduction to slow the progression of the disease. However, a need persists for further development of methods for analysing the effectiveness of existing and potential treatment strategies.

Unloader braces are one common form of treatment for knee OA, which primarily function by applying a moment at the knee to reduce loading and increase joint separation in the medial compartment. We developed a novel method based on measuring brace deflection using motion capture techniques to estimate the mechanical effect of valgus braces. Brace moments computed using the motion capture method for three subjects during static and walking trials were validated using strain gauge instrumentation.

A second, promising treatment option we explored was biofeedback-assisted gait retraining, which uses live feedback to guide subjects towards an optimal and novel gait pattern that lessens medial compartment loads. We developed a biofeedback system that uses real-time kinematic and kinetic input measures to provide a live estimate of knee joint loading using a statistical regression model. By using a large group of training subjects with a variety of gait styles to generate the regression model, the system that was developed can provide feedback of an estimate of the joint contact forces in the knee for a variety of gait patterns.

In summary, we developed (1) a method for measuring the mechanical effect of valgus bracing and (2) a biofeedback system that can be used in gait retraining to provide live feedback of an estimate of knee joint loads. These developments will provide us with the ability to further investigate the effectiveness of these non-invasive strategies for treating medial knee osteoarthritis. In doing so, we will be able to continue developing these treatment options towards providing more pain relief and improvements in function for a larger group of individuals with knee OA, potentially delaying or preventing the need for surgical interventions.

abstract: M.A.Sc.


title: Essays on Banking, Credit, and Money, and their relationship to Output, Population, and Productivity

contributor:
Keay, Ian
Economics

subject: Canadian Economic History

abstract: This thesis studies instances of credit constraints in Canadian history. In Chapter 2, I study the productivity of Canadian industrial establishments in late nineteenth century Canada. In particular, I look at the relationship between the perceived credit worthiness of proprietors of industrial establishments, capital accumulation, and productivity. I show that the productivity gap of 22-38%, between Ontario and Quebec, that existed in 1871, could have been reduced by between a quarter and three quarters if francophone-Catholics had received the same credit ratings as anglophone-non-Catholics. In Chapter 3, co-authored with David Rosé, we study the entry of French Canadian credit unions, caisses populaires, into rural Quebec over the 1911 to 1931 period. Using propensity score matching methods, we showed that the caisses populaires slowed down rural exodus. Sub-districts where a caisse was established exhibited 7-9% higher population growth--total, rural, and French--compared to sub-districts where no caisse was established. In Chapter 4, co-authored with Gregor W. Smith, we look for evidence of a correlation between output growth and inflation, or unexpected inflation, during the interwar period, which featured an abundance of credit, followed by a credit crunch. Using time-series and panel data methods for more than 20 countries, including Canada, we find little evidence of a correlation between unexpected inflation and output growth.

abstract: PhD


title: Investigation of Mud Intrusion Into Sand and its Effect on Soil Properties

contributor:
Dr. Moore, Ian D.
Civil Engineering

subject:
Horizontal Directional Drilling
Drilling Fluid Intrusion
Soil Strength Parameters
Triaxial Testing

abstract:
This research explores drilling mud intrusion into sand surrounding a horizontal boring and its effects on the soil properties. At the first stage, small-scale laboratory experiments investigated the effects of bentonite mud on soil gradation of sand in horizontal directional drilling (HDD). Two pressure vessels were used, one as the test chamber and the other one as a mud tank. A hose connected the bottom of the mud tank, pressurized by connecting it to a compressor, to the lid of the test chamber. The pressurized mud was applied on top of the sand. Eight tests were run on dry sand to monitor the effects of mud penetration into sand of four different factors: mud pressure, bentonite concentration, soil density, and test duration.
At the end of each test, the % bentonite intruded into sand was determined for every 10 mm soil layers as the difference between the % finer than of the initial sand and the mud-sand mix. The results showed a higher % bentonite intruded into sand for loose sand compared with the dense one at the same pressure and bentonite content of the drilling fluid. Also, a higher % bentonite was obtained in the first 4 layers of the soil for the test with a 5% bentonite drilling fluid compared with 3% and 4% ones on the same loose sand and at the same mud pressure; however, this percentage of bentonite intrusion for the bottom layers of the specimen with a 5% bentonite drilling fluid is less than 3% and 4% ones. As expected, more bentonite penetrates into the sand for a constant mud pressure and the same loose state of the sand when tests have longer duration.
In the second stage of the project, triaxial tests were run on remolded sand samples mixed with the measured percentages of bentonite intruded into soil samples seen during the mud intrusion tests. Thus, the soil strength parameters and the undrained shear strength of the sand-mud mixes were obtained at different confining stresses were obtained, considering the effects of mud intrusion on the short-term response of the soil expected during a directional drilling project.

abstract: M.A.Sc.


title: Matter and Minds: Examining Embodied Souls in Plato’s Timaeus and Ancient Philosophy

contributor:
Miller, Jon
Philosophy

subject:
philosophy
philosophy of mind
plato
plotinus
embodied mind
mind
descartes

abstract: With the rise of Platonism influenced by Plotinus and Descartes, philosophers have largely overlooked the fact that Plato directly acknowledges that there is a practical and valuable role for the body. The Timaeus clearly demonstrates that Plato took the idea of embodied minds seriously, not just as an afterthought of the immortal soul. Ultimately this research demonstrates that Plato did not fundamentally have a problem with the mind-body relationship. In offering an argument for Plato’s positive ideas of embodied minds and the necessity thereof, I will also demonstrate, through a historical comparative, why I think the emphasis on mind rather than on embodied mind might have occurred.

abstract: M.A.


title: Exploring Politics, Practices, and Discourses of Harm Reduction in the Overdose Crisis:  the Case of the Tenant Overdose Response Organizers and the “Therapeutic Riskscape”

contributor:
Masuda, Jeffrey
Kinesiology and Health Studies

subject:
Overdose Crisis
Harm Reduction
Health Promotion
Public Health
Risk Environment
Therapeutic Landscape
Downtown Eastside

abstract: Harm reduction, its aspirations, politics, and discourses, have changed dramatically since its origins as a grassroots, drug user-led movement in Canada. Public health played a critical role in helping implement harm reduction, but in doing so has aligned it in ways that have accommodated neoliberal priorities and technocratic discourses, thus contributing to its depoliticization as a social movement. By absconding from meaningfully attending to social determinants of health, which underlie drug-related harm in favour of risk-mitigating individual approaches, public health’s implementation of harm reduction has fallen short in challenging social injustices and inequities at the root of Canada’s legacy of drug criminalization. The arrival of fentanyl and the overdose crisis in Vancouver’s Downtown Eastside (DTES) has proven to be a turning point in this history by leading marginalized tenants of privately-owned single room occupancy (SRO) hotels to organize overdose response for one another. In December 2016, the Downtown Eastside SRO Collaborative Society, a housing advocacy organization, partnered with public health to develop the Tenant Overdose Response Organizers (TORO) program, which uses community organizing to support these efforts. Through participant observation and key stakeholder interviews undertaken between November 2017 and April 2018, this research explores harm reduction’s politics, practices, and discourses through a case study of the novel, peer-led TORO program. I found that despite the hesitancy of public health to support housing advocacy as a critical component of harm reduction, TORO has supported SRO tenants in their responses to oppressive physical, social, and structural environments. My analysis of the work of TORO within the broader context of the DTES has also supported the development of the “therapeutic riskscape” as a theory that attempts to provide an approach to harm reduction that recognizes the recursive relationship between community-driven responses to structural environments and relational experiences of place-based healing.

abstract: M.Sc.


title: Life After Prostate Cancer: An Investigation of Patients' Health-Related Quality of Life, Sexual Outcomes, Mental Health, Social Support, and Healthcare Experiences

contributor:
Pukall, Caroline
Psychology

subject:
psychology
cancer
prostate cancer
health
healthcare
sexual functioning
sexual satisfaction
mental health
health-related quality of life

abstract: Prostate cancer is the most commonly diagnosed cancer in Canadian males. Survivorship rates, particularly for early-stage diagnoses, are high, meaning that the majority of diagnosed individuals must live with the consequences of the disease and its treatments. The purpose of this study was to investigate the experiences of individuals diagnosed with prostate cancer, specifically their health-related quality of life, sexual outcomes, mental health, social support, and experiences with the healthcare system. As well, this study sought to compare the experiences of heterosexual/cisgender and GLBTQ+ (e.g., gay, lesbian, bisexual, transgender, queer) prostate cancer patients. One-hundred and four participants who had been diagnosed with non-metastatic prostate cancer with no other cancer diagnosis completed an online survey which included a demographics questionnaire, questions about cancer diagnosis and treatment history, and measures of health-related quality of life, changes to sexual roles and activities, sexual satisfaction, sexual script flexibility, symptoms of depression and anxiety, social support, and satisfaction with care. In terms of overall health-related quality of life, there was no significant difference between individuals who had or had not undergone surgical treatment; however, surgical patients reported significantly worse urinary incontinence. For individuals with low to moderate sexual functioning, better sexual script flexibility was predictive of greater sexual satisfaction. Compared to their retrospective reports of pre-treatment sexual activity, after treatment, participants engaged in less frequent sexual activity, fewer identified as being in the insertive intercourse role, and many were no longer sexually active. Greater emotional support was predictive of fewer symptoms of depression, which in turn predicted better overall health-related quality of life. With regards to their healthcare experiences, participants most frequently reported wanting information on erectile functioning from their healthcare providers; for all topics of information, there were participants who wanted information from a healthcare provider but did not receive it. Finally, there were no significant differences between heterosexual/cisgender and GLBTQ+ participants on satisfaction with care, mental health, or health-related quality of life. Implications for prostate cancer patient care and directions for future research are discussed.

abstract: M.Sc.


title: Intramolecular Rhodium-Catalyzed Ene-Cycloisomerization Reactions of Thioether and Triorganosilane containing Alkenylidenecyclopropanes:  Novel Metal-Mediated β-Sulfide and β-Silyl Elimination Reactions

contributor:
Evans, P.  Andrew
Chemistry

subject: cyclization Rhodium sulfur silicon heterocyles

abstract:
The transition metal-catalyzed ene-cycloisomerization is a particularly attractive method for the construction of highly functionalized cyclic scaffolds.  Furthermore, many elegant studies over the past few decades have led to the development of several unique methods for this transformation, employing a variety of transition metal-catalysts.  In particular, the ene-cycloisomerization reaction provides carbo- and heterocyclic skeletons in a highly selective and atom-economical manner, thus offering an efficient strategy for the total synthesis of a number of natural products.  The following thesis commences with a very brief introduction followed by two major section (Chapter 2 and 3) and a concluding chapter.
Chapter 1 serves as a brief introduction and provides an overall outline for this thesis.
Chapter 2 provides an introduction to the development of transition-metal-catalyzed ene-cycloisomerization reaction with an overview of the different reaction pathways (Section 2.1).  This chapter is then divided into subsections (2.2-2.9), that are organized based on the nature of the transition metal-catalyzed ene-cycloisomerization reaction, which depends on the degree of saturation in the substrates.
Chapter 3 commences with a review of the utility of alkylidenecyclopropanes (abbreviated thereafter as “ACPs”) in transition metal-catalyzed reactions.  Section 3.2 provides an in-depth discussion of the reactivity of ACPs in these transformations, in which the behavior of these substrates with four different metal catalysts (Pd, Rh, Ru, Ni) is discussed.  Section 3.3 describes our work on the development of the novel rhodium-catalyzed ene-cycloisomerization reaction of ACPs tethered to an allylic sulfide, which undergo an unprecedented β-sulfide elimination/migration to highlight the importance of the organosulfur chemistry.  The subsequent section (Section 3.4) outlines the development of a nickel-catalyzed sulfide elimination/migration to provide products with two new stereogenic centers and one three-membered-ring.  Section 3.5 outlines our efforts towards the rhodium catalyzed β-silyl elimination/migration.  A detailed optimization and scope of this transformation is described, along with mechanistic studies.
Finally, Chapter 4 provides a conclusion and overview of the methodologies described in this thesis and their synthetic application, especially in the synthesis of important natural products.

abstract: PhD


title: The Logically Perfect Language on Words without Objects

contributor:
Smith, Mark
Philosophy

subject:
Ideal Language
Logically Perfect Language
Stuffs

abstract: Bertrand Russell’s logical atomism holds that the world is made up of a body of structured facts composed of simple objects. A Logically Perfect Language (LPL) is constructed to reflect this hierarchy of facts—every sentence in a LPL corresponds to a fact, and how these sentences are related accurately reflects how their corresponding facts are related. This paper is divided into four parts. I will first explain Russell’s conception and construction of a LPL. Then, I will explain Henry Laycock’s modified account of a singular-general dichotomy; propositions about multiple objects and stuffs need to be taken into account. In the third part, I will focus on the difficulty of integrating propositions about the non-discrete liquid-stuff in an objectual language. In the fourth part, I will examine two problems, namely, the semantics-syntax discrepancy in a LPL and the problem of collective predication. Finally, after characterizing the individuation condition for liquid-stuffs, I will motivate individuating them as discrete portions for the purposes of particular predication. I will develop a new conception of what constitute a single instance of liquid-stuff, and use this new conception to characterize the preliminary works before the construction of a LPL for liquid-stuffs.

abstract: M.A.


title: Investigating metabolomic and phenotypic changes following exercise training and corresponding implications for cardiometabolic risk

contributor:
Ross, Robert
Kinesiology and Health Studies

subject:
metabolomics
aerobic exercise
adipose tissue
interindividual variability

abstract: The purpose of this dissertation was to study the effects of exercise training on the plasma metabolome and phenotypic changes in men and women with abdominal obesity, using both metabolomics and magnetic resonance imaging technologies. Our findings are based on data collected from a randomized controlled trial, wherein participants were assigned to a low amount low intensity, high amount low intensity, high amount high intensity, or control group. The objective of Study 1 was to examine plasma metabolome changes in response to chronic exercise and whether changes in metabolites are associated with change in cardiometabolic risk factors. While no significant differences between measured metabolites in the control and exercise arms were observed, we identified significant associations between changes in metabolite concentrations and improvements in cardiometabolic traits following exercise. These findings were based on the average group response; however, recent interest in personalized exercise medicine has prompted investigation of individual responses to exercise training. Given the epidemic of excess adiposity globally, characterizing the heterogeneity in adipose tissue (AT) response to exercise is clinically important. The objective of Study 2 was to characterize the magnitude and clinical relevance of individual responses for AT reduction following standardized exercise. We demonstrated that the probability of an individuals’ reduction in total and abdominal AT being clinically meaningful was greater than controls, independent of amount and/or intensity. The objective of Study 3 was to integrate our findings by assessing the influence of AT reduction on the plasma metabolome and subsequent changes in cardiometabolic risk following exercise. We found that exercise-induced reduction in visceral AT was independently associated with increases in pyroglutamic acid (linked to glutamate metabolism) and TCA cycle intermediates (succinic and fumaric acid). Taken together, our observations suggest that (1) alterations in metabolites are related to changes in cardiometabolic traits; (2) part of the relationship between metabolite changes and cardiometabolic traits may be explained by AT reduction following exercise; and (3) given that the magnitude of adiposity reduction is associated with identifiable plasma metabolites, it is possible blood-based measures can reflect a given individual’s AT response to exercise.

abstract: PhD


title: .Compostmodernism: A Theory for the Infiltration of Digital and Internet Technologies in Twenty-First Century American Fiction

contributor:
Wallace, Molly
English Language and Literature

subject:
post-postmodernism
digital humanities
.compostmodernism
postmodernism
modernism
twenty-first century literature
contemporary
literary fiction
digital culture
new sincerity
post-irony
postmodern irony
cyber-consciousness
literary cyber-consciousness
textual machine
.compostmodern machinery

abstract: This dissertation introduces and defines .compostmodernism as a successor to postmodernism in the particular context of twenty-first century literature. Having roots in the postmodern literary era when the anxiety about print literature’s obsolescence was at its peak, .compostmodernism is born of the increasing influence of media and technology on literature in the late twentieth and early twenty-first centuries. The dissertation begins by defining postmodern literature’s relationship to new media and technology in the 1960s and beyond, working toward the various definitions for post-postmodernism today. Following, it offers a definition of .compostmodernism as the literary composting of “dead” and bygone postmodern and modern literary tenets—namely postmodern irony and new (modern) sincerity— with twenty-first century digitality in content, narrative form, typography, materiality and finally, medium before offering a preliminary case study with Thomas Pynchon’s Bleeding Edge (2013). Through a close reading of Tao Lin’s Taipei (2013), it introduces literary cyber-consciousness as a crucial component of the .compostmodern novel: a narrative form that, while composting postmodern self-parody and modern stream of consciousness, emerges as the literary embodiment of the intermediation between human cognition and the digital machine. Through a visual engagement with Mark Z. Danielewski’s The Familiar (2015), it introduces .compostmodern textual machinery, a two-tiered machine. First, the printed book is a textual machine in which the novel’s typographical experimentation visually reflects the metaphorical digital machinery of the codex and second, the reader’s physical relationship to the text as prompted by the typographical experimentation emerges as a mode of .compostmodern operation. The dissertation concludes by opening up .compostmodernism’s potential beyond literary fiction and exploring its presence in Amaranth Borsuk and Brad Bouse’s poetry collection, Between Page and Screen (2012) and Skip Brittenham and Brian Haberlin’s genre fiction graphic novel, Shifter (2013). While offering a set of solid .compostmodern applications in literature, this dissertation begins the important conversation around literature’s survival in an increasingly digital culture.

abstract: PhD


title: An examination of team structure and its implications for subgroups in an individual sport setting

contributor:
Martin, Luc
Kinesiology and Health Studies

subject:
Subgroups
Cliques
Team Structure
Individual Sport
Interdependence

abstract:
Despite growing research interest in the social dynamics of sport teams, the smaller groups that emerge from within a total team have largely been overlooked.  This is concerning given that preliminary investigations highlight the inevitability of their presence, in addition to the potential for them to generate both adaptive and maladaptive outcomes (Martin et al., 2015, 2016; Wagstaff et al., 2017).  However, several shortcomings identified in this exploratory body of literature were its (a) inclusion of only one perspective (either athletes or coaches), (b) from a range of different sport teams, without consideration for (c) changes over time, and (d) the specific sport structure that might predispose division within a team.  As such, the purpose of this study was to explore how sport structure predisposes a team to subgroup and clique formation, and thus, influences athlete interactions and team functioning.  Track and field was chosen as it represents an individual sport composed of several smaller teams ranging in teammate interdependence and event types.
An in-depth case-study design was selected, composed of several interviews conducted over the course of a competition season.  A single Canadian intercollegiate track and field team was selected, wherein 15 participants (4 coaches, 11 athletes) provided various perspectives from across the team.  Semi-structured interviews were conducted early and post season, and transcripts were analyzed using a combination of thematic and exception analyses (Braun et al., 2016; Phoenix & Orr, 2017).
Results indicated that this track and field team had a multitude of inherent structural constraints (sport type, event type, facility/schedule limitations, team size, change over time) that directly impacted athlete interactions and predisposed the group to subgroup and clique formation. Consequently, much of the team’s energy was directed toward the management of the social environment (e.g., athlete interactions, cooperation) by undertaking team building activities, utilizing the leadership core, emphasizing consistent and quality communication, and generating individual buy-in.  These findings have both theoretical and practical implications and are discussed as they related to the literature.  Future directions and study strengths and limitations are advanced herein.

abstract: M.Sc.


title: Mechanisms Contributing to the Specificity of Gynephilic Men’s Sexual Responses

contributor:
Chivers, Meredith
Psychology

subject:
Visual attention
Genital response
Homonegativity
Disgust
Sexual arousal

abstract: Men’s sexual responses have historically been characterized by their gender specificity, meaning that men show stronger genital and subjective arousal to preferred (i.e., sexual stimuli that include one’s preferred gender) versus non-preferred (i.e., sexual stimuli that do not include one’s preferred gender) sexual stimuli. But recent work suggests that many gynephilic (i.e., sexually attracted to women) men show varying degrees of same-sex attraction, fantasies, and behaviours. Previous research on men’s gender-specific sexual responses has not investigated potential bidirectional relationships between men’s attentional, affective, and genital responses to non-preferred sexual stimuli. New information about these relationships will contribute to our understanding of gynephilic men’s capacity for nonexclusive sexual attractions. Two models of sexual responding, the information processing model and the incentive motivation model, include pathways that detail the role of initial attention, controlled attention, and affect in activating or inhibiting arousal to nonpreferred sexual stimuli. Across two studies, these models of sexual responding are used as a framework to explore how greater negative affect (i.e., homonegativity and trait-level disgust) and attentional biases (i.e. vigilant initial attention and avoidant controlled attention) reduce men’s sexual responses to non-preferred sexual stimuli. In Study 1, which examined men’s detection of human stimuli at the earliest stages of stimulus processing, gynephilic men were more accurate when they identified images of nude women than when they identified images of clothed men or clothed women. There was no significant difference in their speed and accuracy, however, when detecting nude women versus nude men, suggesting that gynephilic men’s gender-specific sexual responses may only occur during later stages of processing. In Study 2, which examined men’s visual attention and genital responses during later stages of stimulus processing, greater levels of homonegativity and trait-level disgust predicted attentional avoidance of sexual stimuli featuring men, as well as lower genital responses to these stimuli. Results expand our current understanding of men’s sexuality by identifying factors that contribute to gender-specific and gender-nonspecific sexual responses in gynephilic men. Future work should explore whether gynephilic men’s sexual behaviours become increasingly malleable as society continues to become more accepting of same-sex sexuality.

abstract: M.Sc.


title: The Parallel Squat: A Comparison Between Kinematic, Kinetic, and Muscle Activity Components of Measurement

contributor:
Costigan, Pat
Kinesiology and Health Studies

subject:
Biomechanics
Movement quality
Movement symmetry
Kinematics
Kinetics

abstract:
Movement quality screening tools have been developed to reduce the risk of injury and enhance physical performance. These screening tools use observational techniques to analyze movement and identify faulty movement patterns. One variable that is used in some screening tools and that is a valid predictor of injury is movement asymmetry. The issue is that screening tools are currently assessing asymmetry from a kinematic perspective by observing the individual during their movement execution, while discounting potential asymmetric behaviour at the kinetic or muscle activity components of movement. The purpose of this study was to evaluate movement asymmetry from a kinematic, kinetic, and muscle activity component to identify whether differences exist between the components of movement.

Kinematic, kinetic, and muscle activity data were collected from thirty-four healthy young adults as they performed twenty-five parallel squats in five conditions: normal, slow metronome, normal metronome, fast metronome, and weighted squat. The kinematic component was represented by joint angles, while the kinetic component was represented by joint moments and the muscle activity component was represented by electromyography amplitude. Cross-correlations and normalized RMS values were calculated between the left and right ankle, knee, and hip at each component of measurement. Multiple two-way repeated measures ANOVAs assessed the difference between the conditions and the components of measurement.

Results demonstrated a significant difference in cross-correlations and normalized RMS values between the kinematic, kinetic, and muscle activity components at the ankle, knee, and hip. Generally, there was no significant difference between the conditions in terms of asymmetry measures. These results present an important consideration for movement quality screening tools: are we getting the full picture when evaluating movement using observational techniques and focusing on kinematic measures?

abstract: M.Sc.


title: Exploring Perceptions of Public Stigma as a Mediator in the Relationship between Number of Depressive Symptoms and Mental Health Treatment-Seeking Behaviours

contributor:
Stuart, Heather
Stuart, Heather
Public Health Sciences

subject: public stigma, treatment-seeking, help-seeking, depression, symptoms

abstract:
Background: Individuals with more depressive symptoms are more likely to seek treatment. However, there is evidence suggesting that these same individuals may be more likely to feel stigmatized. As expectations of public stigmatization may discourage treatment-seeking from those who would benefit the most, it is important to gain a better understanding of the interplay among these variables.
Objective: The aim of this thesis was to determine if perceived public stigma towards people with depression acts as a mediator in the relationship between the number of depressive symptoms and mental health treatment-seeking behaviour.
Methods: This study utilized secondary, cross sectional data from Statistics Canada’s 2010 Canadian Community Health Survey, including a rapid response stigma module. Participants (ages 12-101) were from the regions of Prince Edward Island, Quebec, Alberta, and the Northwest Territories and were interviewed between May-June 2010 (N = 2,087). SAS 9.4 survey procedures incorporated the sampling weights and bootstrap variance estimation procedures. Multiple linear regression and logistic regression were used to assess the associations of interest. Sobel’s formula for standard error was used to construct 95% confidence intervals around the estimate of the indirect effect.
Results: For both females and males, the number of depressive symptoms experienced positively predicted the likelihood of mental health treatment-seeking. In females, but not in males, there was a significant, positive association between number of depressive symptoms and perceived public stigma. For both females and males, when the number of depressive symptoms was statistically controlled, there was no association between perceived public stigma towards depression and mental health treatment-seeking. Perceived public stigma towards depression did not mediate the relationship between number of depressive symptoms and mental health treatment-seeking behaviour.
Conclusion: Results of this study show that perceived public stigma towards depression does not mediate the relationship between number of depressive symptoms and mental health treatment-seeking behaviour. As one of the first studies to assess the associations among number of depressive symptoms, perceived public stigma towards depression, and mental health treatment-seeking behaviour, the results from this study contribute new information to the mixed body of literature.

abstract: M.Sc.


title: The association between area- and individual-level risk factors and chlamydia infection a sexual health clinic

contributor:
Richardson, Harriet
Harvey, Bart
Majury, Anna
Public Health Sciences

subject:
sexual health
chlamydia
epidemiology
public health
STI

abstract:
Background: Chlamydia is the most common sexually transmitted infection (STI) in Canada. Although the literature has focused on individual-level risk factors as the greatest determinants for chlamydia infection, more recent research has investigated the role of neighbourhood socioeconomic status (SES) on risk for chlamydia infection. The present study aims to investigate the relationship between multiple area- and individual-level risk factors and chlamydia infection in a sexual health clinic.

Methods: Individuals who were tested for chlamydia at the Kingston, Frontenac and Lennox & Addington (KFL&A) Public Health sexual health clinic from April 2016 to March 2017 were included in this study. The four indices of the Ontario Marginalization (ON-Marg) Index; namely, material deprivation, dependency, residential instability and ethnic concentration, were used as measures of neighbourhood SES. Individual-level risk factors included variables that were captured from the questionnaire administered at the time of examination. Logistic regression was used to compute odds ratios (OR) for all risk factor variables. Outcome data was plotted on a geographic information system (GIS) to compare marginalization differences based on chlamydia test result.

Results: A total of 1775 individuals were tested for chlamydia at the Clinic, with 208 (11.7%) testing positive on their first Clinic visit. Age (OR=4.84, 95% CI 2.18-10.74; <20 versus >40 years), number of sexual partners in the previous 2 months (OR=3.11, 95% CI 1.06-9.10; 2 partner versus no partners), condom use (OR=2.09, 95% CI 1.07-4.09; rarely versus always using condoms), and STI contact (OR=6.16, 95% CI 4.35-8.74) were significant individual-level predictors for infection. Apart from ethnic concentration of the ON-Marg Index, there was a trend suggesting an association between the highest levels of marginalization and increased odds of chlamydia infection compared to the lowest levels of marginalization. However, this association was only statistically significant for the dependency index (OR=1.90, 95% CI: 1.05-3.43; most deprived versus least deprived).

Conclusions: Populations living in highly marginalized neighbourhoods, an established marker of low SES, were found to be at a significantly higher odds for chlamydia infection for one of the four ON-Marg indices; namely, dependency. More research is warranted to further clarify the role of neighbourhood SES on the risk of chlamydia infection.

abstract: M.Sc.


title: Carbon assisted atmospheric pyrite oxidation to enhance reaction kinetics and elemental sulphur yield

contributor:
Ghahreman, Ahmad
Mining Engineering

subject:
Atmospheric oxidation
Pyrite
Elemental sulphur
Sulphuric acid
Activated carbon
Ferric sulphate

abstract: Pyrite is an important mineral due to its ability to contain high concentrations of gold. Unfortunately, pyrite does not typically allow for conventional gold leaching, and often an oxidative pre-treatment process must be applied in order to recover the refractory gold. Oxidative pre-treatments exist in a variety of forms categorized under either pyrometallurgical or hydrometallurgical processes. Further hydrometallurgical pre-treatment methods must be investigated in order to meet the current demands of the industry due to the ever changing types of gold deposits. This study investigates the effectiveness of two carbon-based oxidation rate enhancing additives, Lewatit® AF 5, a micro/mesoporous carbonaceous bead, and granular coconut shell activated carbon in the atmospheric oxidation of pyrite and their ability to promote elemental sulphur generation rather than sulphuric acid. Pyrite oxidation in the absence of the carbon additives was 60% after 96 h, with elemental sulphur yields ranging between 16% and 28%. Under the same test conditions, oxidation tests assisted by AF 5 resulted in approximately 96% pyrite oxidation with elemental sulphur yields ranging between 54% and 63%, while activated carbon assisted oxidation reached virtually 100% pyrite oxidation with elemental sulphur yields between 53% and 54%. AF 5 indicated superior mechanical properties and elemental sulphur retention when compared to activated carbon, resulting in its choice for an additional parameters study. Characterization of the two carbon additives indicated the presence of amino acid group L-cystine on AF 5, absent from activated carbon, which was believed to promote the sulphur retention observed with AF 5. Parameters testing indicated that AF 5 was a versatile additive to atmospheric pyrite oxidation as elemental sulphur yield and oxidation was not greatly impacted by varying parameters when AF 5 was present. The highest oxidation and elemental sulphur yields were achieved at a concentrate to carbon additive ratio of 1:2 and a temperature of 90 oC, however. A final study conducted using polyethylene terephthalate (PET) and high-density polyethylene (HDPE) doped with L-cystine did indicate that L-cystine did enhance elemental sulphur retention, and helps to explain AF 5’s sulphur retention.

abstract: PhD


title: Physical Activity Participation in Ovarian Cancer Survivors: Prevalence, Determinants and Association with Patient Reported Outcomes

contributor:
Richardson, Harriet
Koushik, Anita
Public Health Sciences

subject:
Epidemiology
Ovarian Cancer
Physical Activity
Health-Related Quality of Life
Patient Reported Outcomes
Prevalence

abstract:
Objectives: The primary objectives were (1) to estimate the prevalence of meeting physical activity (PA) guidelines among ovarian cancer survivors in the post-treatment period and (2) to identify the determinants of meeting PA guidelines in this study population. The secondary objective was to explore the association between PA and patient reported outcomes (PROs), specifically health-related quality of life (HRQOL), anxiety and depression symptoms.

Methods: The Lifestyle Habits and the PRognosis of Ovarian Cancer in Quebec (HPROQ) Study is a prospective cohort study that was conducted in Montreal (2015-2018). For this thesis, a cross-sectional study was conducted on the baseline cohort. 112 ovarian cancer survivors were interviewed 6 months after treatment completion. Modified Poisson regression was used to estimate the prevalence ratio (PRs) and 95% confidence intervals (CIs) to describe the association between patient characteristics and the prevalence of meeting PA guidelines. Multivariable linear and logistic regressions were used to examine the association between meeting PA guidelines and PROs.

Results: 42.0% (95% CI: 32.8-51.1%) of ovarian cancer survivors met the PA guidelines of at least 150 minutes of moderate PA per week. There was no evidence of a statistically significant association between any of the potential determinants and meeting PA guidelines. Employment had the highest PR, suggesting that women who were employed had a prevalence of meeting PA guidelines that was 1.49 times greater than women who were unemployed (PR=1.49; 95% CI:0.87-2.55). There was no statistical evidence of an association between meeting PA guidelines and better HRQOL or reduced anxiety and depressive symptoms. PA was most protective for depressive symptoms, suggesting that women who met PA guidelines had odds of depressive symptoms that were 0.30 times greater than women who did not meet PA guidelines.

Conclusions: The prevalence of meeting PA guidelines 6 months after treatment was higher than reported in previous studies. None of the potential determinants were significantly associated with meeting PA guidelines, nor was meeting PA guidelines significantly associated with improved PROs. Due to the small sample size the study was underpowered, making it difficult to exclude chance as an explanation for some of the more suggestive associations observed in this thesis.

abstract: M.Sc.


title: Hydrogen Gas Production and Effects During Remediation Using Nano-scale Zero-valent Iron

contributor:
Mumford, Kevin
Civil Engineering

subject:
Nano-Scale Zero-Valent Iron
Hydrogen Gas Exsolution

abstract:
The objective of this study was to develop an understanding of the potential effects of hydrogen gas (H2) exsolution during nanoscale zero-valent iron (nZVI) groundwater remediation applications. An improved understanding of gas exsolution and its effects can be applied to remediation technologies that produce gas in excess of solubility limits, including bioremediation and nZVI. Experiments were performed in thin flow cells packed with water- saturated silica sands.
Differential pressure measurements were taken under saturated conditions, after H2 gas exsolution and during gas dissolution. Images were processed with a quantitative light transmission technique to visualize and quantify gas production and transport, and to investigate flow diversion around the injection zone. In a larger-scale experiment, images were processed qualitatively to visualize gas production and transport, and to investigate flow diversion around the injection zone. Water samples were collected and analyzed for contaminant mobilization and redistribution to upper portions of the flow cell. The exsolution of H2 gas caused reductions in hydraulic conductivity with lower values associated with higher gas saturations. Images obtained from dye tests in all experiments demonstrated significant reduction in hydraulic conductivity due to H2 gas produced, with flow diversion of dye solution around the injection zone. The study demonstrated that the dissolution of exsolved gas can be used to investigate relative permeability at small saturation increments and at lower trapped gas saturations than can be obtained using external displacement experiments. H2 gas exsolved due to the reaction of nZVI with water was greater than the H2 gas produced by the self- hydrolysis of NaBH4 solution injected into saturated sands, despite using similar NaBH4 concentration as excess for nZVI synthesis. In the large-scale experiment, the exsolved H2 gas volume was sufficient to produce trapped gas in the injection area, and gas that travelled upwards and away from the injection area as gas channels. Vertical gas transport occurred above a high-concentration trichloroethene (TCE) plume, resulting in its redistribution of TCE, as well as ethene and ethane transport along the gas channel fronts.

abstract: PhD


title: Investigating the Role of Phosphodiesterase 1C in Vascular Smooth Muscle Cell Migration and Invasion

contributor:
Maurice, Donald H.
Biomedical and Molecular Sciences

subject:
PDE1C
Migration
Invasion
Spheroids
Cyclic Nucleotide Phosphodiesterase
Vascular
Smooth Muscle Cell

abstract: Phenotypic plasticity of human arterial smooth muscle cells (HASMCs) allows them to transition from a “contractile/quiescent” state, in which they regulate arterial tone and blood pressure, to one in which these cells are more “synthetic/activated”. Synthetic/activated HASMCs are migratory and proliferative, and these capabilities allow them to participate in vasculogenesis during development, as well as post-natal vessel repair. Although several laboratories have investigated the overall inhibitory influence of cAMP-elevating agents on HASMC migration, few have addressed whether cAMP signalling also coordinates HASMC invasion of extracellular matrices, a critical first step in HASMC migration in vivo. Indeed, while several cAMP-elevating agents reduce intimal hyperplasia/hypertrophy in animal models, it is presently unclear whether these effects are due to reduced matrix invasion of these cells or solely to inhibition of their migratory capacity. Previous work conducted by our group and others have identified the critical role of cyclic nucleotide phosphodiesterase 1C (PDE1C) in HASMC migration, proliferation, and extracellular matrix adhesion. Here, we directly tested the hypothesis that cAMP signaling, and specifically PDE1C, influences the ability of activated/synthetic HASMCs to invade matrix in 3-dimensions (3D) and show that this effect is distinct from their migratory actions. Overall, we observed that inhibiting PDE1C activity reduced invasion of 3D collagen matrices by these cells to a greater degree than it did migration in systems not requiring invasion. Using a spheroid model, it was found that either inhibition of PDE1, or the selective silencing of PDE1C, reduced the distance of sprout outgrowth. Of importance in assessing how PDE1C regulates matrix invasion, we investigated whether HASMCs invading collagen matrices generated matrix degrading structures, specifically podosomes. Our data, although preliminary, is consistent with this idea. Similarly, initial success at generating mixed spheroids of human endothelial and SMCs cultures is presented. In these latter experiments, we used telomerase immortalized human aortic endothelial cells (TeloHAECs). This work reports that inhibiting or silencing HASMC PDE1C preferentially impacts invasion over migration of these cells. This aids in bridging the gap between in vitro and in vivo effects of PDE1C, and in HASMC evaluation of its potential as a therapeutic target.

abstract: M.Sc.


title: Static Liquefaction of Loose Granular Landslides

contributor:
Take, Andy
Civil Engineering

subject:
Landslide
Static liquefaction
Liquefaction

abstract: Highly mobile landslides can have devastating impacts on infrastructure and human life.  In order to mitigate the risks of these landslides, it is critical to understand how they are triggered and the mechanism behind their high mobility.  The objective of this research is to investigate the initiation and propagation of liquefaction and the resultant flow mobility due to static triggering in loose granular slopes using two physical modelling techniques. The first experiment used geotechnical centrifuge techniques to determine the velocity of the liquefaction propagation in saturated granular slopes for loose and dense soils, by varying the thickness and void ratios of the materials. The results of these tests indicate that all model slopes which were loose of the critical state were highly liquefiable upon shearing, while all dense tests resisted liquefaction and instead were subject to erosion as they could withstand much higher seepage flow rates. Tests that experienced liquefaction reveal that the velocity of the liquefaction propagation is not dependent on the velocity of shearing of the initial failure (0.25-0.5 m/s), and that the speed of propagation of the liquefaction front can happen at an order of magnitude faster than that of the initial triggering event (4.2-4.3 m/s). A second series of experiments was performed to develop testing techniques and best practices for dam breach experiments using a large-scale flume.  In this test series, both saturated fine sand and coarse grained material were examined.  Results from testing the saturated coarse grained material show that landslide mobility increases with respect to dry flow when the material is saturated. As expected, the increase in mobility with the addition of water is due to the proportional decrease in basal shear resistance. In contrast, the same experiment with fine sand did not experience failure and most of the material remained in the release box. This surprising finding indicates the possible significant role of air entry and matric suction on the higher strength in the latter case and indicates an interesting avenue for future research to quantify this phenomena.

abstract: M.A.Sc.


title: Self-assembled Monolayers of N-Heterocyclic Carbenes on Gold and Their Applications

contributor:
Crudden, Cathleen M.
Chemistry

subject:
chemistry
materials chemistry
materials science
self assembled monlayers
surface science
catalysis
renewable fuel

abstract:
N-Heterocyclic carbenes (NHCs) are excellent ligands for metal coordination and have been studied extensively. NHC metal complexes have also been used for many different catalytic applications. One such application of these complexes is their use in water oxidation catalysis as described by Albrecht. In Chapter 2 we will discuss the progress made in tethering water oxidation catalysts to gold surfaces via NHC self-assembled monolayers (SAMs). This project bridges the gap between NHCs for surface science applications and for homogeneous catalysis. Two main routes were explored for this project to immobilize an iridium-based water oxidation catalyst. The catalyst was synthesized either on or off of the NHC SAM support. Several generations of the catalysts were tested for catalytic activity for water oxidation catalysis and this too will be discussed in Chapter 2.
	Recently it has been shown by the Crudden group and others that NHCs are excellent surface ligands with high stability for Au(111). The preparation of these materials have recently improved using simple benchtop methods, which will be discussed in Chapter 3, instead of generating the free carbene using strong base and inert atmosphere. Hydrogen carbonate salts of NHC precursors were used to deposit an NHC SAM on Au(111) in situ with HPLC methanol. These films were found to have the same characteristics and stability as those deposited using the free carbene. In Chapter 3 we also describe the use of other azolium salts with non-coordinating counterions to deposit NHC SAMs on Au(111) without the need to create the hydrogen carbonate salts. This simplifies the benchtop method even further as ion exchange reactions are no longer necessary for NHC SAM deposition.

abstract: PhD


title: What's odd? Cognitive processing of social contexts based on autistic traits within the general population

contributor:
Castelhano, Monica
Psychology

subject:
autism spectrum disorders
visual cognition
eyetracking

abstract: Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterized by social and communicative deficits, such as being able to identify and understand a joke. These social deficits can be understood in a cognitive framework; smaller differences in perceptual processing can snowball into tangible larger differences in complex and dynamic social situations (Benson, Castelhano, Howard, Latif & Rayner, 2016; Minshew & Goldstein, 1998). For example, individuals with ASD have a greater difficulty with tasks requiring higher-order or complex cognitive processing (Minshew & Goldstein, 1998; Benson et al., 2016). The present study extends prior research examining ASD-like cognitive processing styles in non-clinical individuals by examining how different levels of ASD-like traits in the general population can affect perception of social contexts (Baron-Cohen et al., 2001; Bayliss & Tipper, 2006; Ruzich et al., 2015). ASD-like traits were measured by the Autism Quotient (AQ; Baron-Cohen et al., 2001). Participants completed a visual/social oddity task that varied on whether complex or simple processing of a visual scene was required. Scenes could be visually odd (e.g., girl with a vase as a “third leg,” which requires simple re-parsing of visual features, or socially odd (e.g., a man walking a lettuce on a leash), which requires integration of past knowledge of social norms. If ASD-like traits are linked with impaired complex but not simple processing we expect people with high ASD-like traits to show differing eye movement patterns for socially odd (complex) but not visually odd (simple) stimuli, with no differences for those with low traits. No significant interactions or main effects were found for differing levels of ASD-like traits.

abstract: M.Sc.


title: Walking Toward Respect: Historical Geographies of Nature and Possibility in UNESCO MAB’S Frontenac Arch Biosphere Reserve

contributor:
Cameron, Laura
Geography and Planning

subject:
walking methodology
historical geographies of nature
Frontenac Arch Biosphere Reserve
UNESCO
MAB
Biosphere Reserves

abstract: This thesis employs an innovative methodological approach to provide a historical geography of the Frontenac Arch Biosphere Reserve (FABR), an area designated by the United Nations’ Educational, Scientific, and Cultural Organization’s Man and the Biosphere (MAB) program. Through a walking research method conducted in five hiking locations within the FABR, I identified important themes and current issues related to the key concepts used to define and understand biosphere reserves; ecology, ecosystem, conservation, and sustainable development and followed them back through the institutional history of MAB. By attending to the complexity of meanings held by each of the key concepts, the research seeks to identify moments of possibility within MAB’s past for promoting the FABR's purpose as a site of socio-ecological learning. These moments are at risk of being forgotten as social issues are generally overshadowed by a focus on economic development within the World Network of Biosphere Reserves. The research presented here provides important historical and political context to help situate the current approach to sustainable development at the FABR by attending to three other overlapping institutional temporal scales centered around the following key events: the creation of UNESCO and its conservation organizations from 1929-1969; the planning and implementation of the MAB program from 1968-2000; and finally, the implementation of Canada’s national MAB program from 1972-2000. The key contributions of this work include a historical geographical methodology that blends embodied walking research with archival inquiry, a summary of resources from MAB’s history for biosphere reserve practitioners in Canada who are working towards building positive cross-cultural relationships with Indigenous individuals and organizations, and the documentation of key insights from MAB’s history related to ongoing efforts in the discipline of geography to a meaningful integration of the human and physical sciences.

abstract: PhD


title: Natural Movements of Smallmouth Bass and Their Response to Tournament Displacement Within the Eastern Basin of Lake Ontario

contributor:
Tufts, Bruce
Biology

subject:
Acoustic Telemetry
Angling
Smallmouth Bass
Movement
Navigation
Lake Ontario
Displacement

abstract: Smallmouth Bass (Micropterus dolomieu) are one of the most popular species targeted by angling tournaments in North America, particularly in the Great Lakes region. Tournament anglers target the largest fish in these populations and can transport them across great distances (>100 km), generating concern among scientists and anglers about their ability to return to their established home ranges. Understanding the movement of sport fish by tournament anglers can aid in managing the large recreational fishery that exists in the Great Lakes region. Currently, there is insufficient research examining the natural movements or long-distance displacement of bass within large waterbodies. This study investigates tournament displacement within the Eastern Basin and the natural, non-displaced, movements of these fish. A dataset (2012 – 2016) of externally tagged Smallmouth Bass was used to examine movement, both natural and post-tournament displacement. In addition, acoustic telemetry was used to monitor the movements of an experimentally displaced and non-displaced group. From initial tagging to recapture, experimentally tagged displaced fish travelled an average of 23.4 km, while the control group travelled an average of 2.91 km. Both groups had similar lengths of time between tagging and recapture. The acoustically tagged control group were frequently detected within their initial tagging site, suggesting these fish maintain home ranges similar in size with Smallmouth Bass inhabiting smaller waterbodies. Both experimental groups displayed varying movement throughout the Eastern Basin, suggesting that many of these fish may be searching for pre-established home-ranges. No acoustically tagged fish displaced within the Eastern Basin returned to their original area of capture, suggesting they experienced difficulty navigating. These results have very important implications for fisheries managers, as well as organizers of competitive angling events for bass in the Great Lakes.

abstract: M.Sc.


title: Nanoplasmonic Sensors Based on Chirped Crossed Surface Relief Gratings

contributor:
Escobedo, Carlos
Sabat, Ribal
Chemical Engineering

subject:
Surface Plasmon
Sensors
Gratings

abstract: This work presents a new type of nano-plasmonic sensor based on crossed surface relief gratings (CSRGs) with gradually varying pitch generated on top an azobenzene thin films using a 532 nm laser and a modified Lloyd mirror setup. A cylindrical lens is placed in front of half of the beam’s path, scattering the light horizontally, which results in the varying pitch linear gratings. Crossed gratings are created by writing a varying pitch grating on top of an orthogonally placed constant linear grating; therefore, producing a chirped-pitch cross grating. CSRGs have already created a unique surface plasmon resonance (SPR) sensors, since no light passes through them except a narrow bandwidth where SPR conversion occurs. A large bandwidth of SPR wavelengths are excitable along the chirped grating, making them suitable as a new generation of biosensor that obtains an accurate signal using multiple wavelengths of light upon a biological or biochemical event. Alternatively, the sensor can be divided up to different sections, where each section could be used as a device by itself, with specific photonic characteristics, that can be tailored for multiple, specific, biosensing requirements.

abstract: M.A.Sc.


title: Novel Reagents for the Determination of Calpain Activity In Vitro and In Vivo

contributor:
Davies, Peter L.
Biochemistry

subject:
Cysteine Protease
Calpain
Calpain Substrate
Calpain Inhibitor
Calpain-3
Insertion Sequence (IS1)
Limb-Girdle Muscular Dystrophy Type 2A
Calpastatin

abstract:
Calpains are multi-domain intracellular Ca2+-activated cysteine proteases. They participate in a number of cellular processes downstream of calcium signaling. Unregulated calpain activity, caused by a loss of calcium homeostasis, has been implicated in a variety of pathologies. For that reason, studying calpain structure-function is of great biomedical interest. Nevertheless, some fundamental questions regarding the behaviors of these proteases remain unanswered largely due to the low sensitivity and poor calpain-specificity of the current methods to measure calpain activity. To address this deficiency, we designed, characterized and optimized a fluorescent protein-based FRET substrate centered on the highly calpain-sensitive PLFAAR cleavage sequence. This reagent proved superior to the endogenous substrate α-spectrin both in vitro and in vivo, making it feasible to accurately determine when, where, and under what circumstances calpain is activated in cells. This substrate may also be useful for the identification of relevant calpain substrates and the assessment of calpain-specific inhibitors in vivo.
	Calpain-3 is a tissue-enriched isoform whose loss of function causes limb-girdle muscular dystrophy. Due to its instability, largely conferred by its unique insertion sequences, recombinant expression of the full-length enzyme has not been possible. To study the function of insertion sequence one (IS1), we designed and characterized a recombinant calpain-2 surrogate with IS1 inserted into the protease core in its calpain-3-equivalent position. As it does in calpain-3, IS1 occupied the catalytic cleft of the surrogate, restricting access of substrates and inhibitors, establishing its propeptide potential. Surprisingly, the natural calpain inhibitor calpastatin was able to displace IS1 from the active-site and block protease activity. However, this is unlikely to occur in vivo because calpain-3 homodimerizes and presents only one set of PEF domains to hold calpastatin via its anchoring subdomains. We also characterized a protease core from human calpain-3 missing IS1, which showed that IS1 autoinhibition accounts for a nearly 2-fold loss in enzyme activity. Despite the sequence and structural similarities of this protease core with that of calpain-1, small-molecule calpain inhibitors were less effective on this isoform, suggesting that subtle differences in the subsites of the calpain-3 catalytic cleft may confer sufficient isoform-specificity for the development of relatively calpain-3-specific inhibitors.

abstract: PhD


title: “The Disease that Knowledge Must Cure”?  Sites of Uncertainty and Imagined Futures of Baker Lake, Nunavut

contributor:
Hird, Myra J.
van Wyck, Peter C.
Environmental Studies

subject:
Resource development conflict
Uncertainty
Indigenous peoples
Environmental assessment

abstract: After nearly eight years of formal environmental review, in July 2016, the Canadian federal government rejected the French multinational AREVA’s proposal to construct a uranium mine 80 kilometers west of Qamani’tuaq/Baker Lake, a small inland and mainly Inuit hamlet in the Kivalliq region of Nunavut. The decision not to grant a license for resource development was based on a technical uncertainty, that is, AREVA was not able to provide a start-date for the mining project due to the depressed uranium market. Yet, as this thesis will demonstrate, this controversy underlies a far more complex and ongoing negotiation with uncertainty. In order to explore diverging engagements with uncertainty, this thesis develops the concept of sites of uncertainty, which are spaces —physical, temporal, emotional, material, discursive and so on—that are occupied by a “state of not knowing” (Cameron, 2015: 34). Drawing on qualitative fieldwork conducted in Baker Lake in November and December of 2016, this thesis will identify key sites of uncertainty where AREVA, government officials, Inuit organizations, and community residents constructed, negotiated, expressed, transformed, experienced, and responded to uncertainty. The analysis of these sites reveals diverse, dynamic, and conflicting conceptualizations of self-sufficiency, well-being, and ultimately identity, which, this thesis argues, led to muddy responses to AREVA’s proposal as well as imagined futures of Baker Lake. Moreover, this thesis explains how local residents’ calls for improvements in education are reflective of an intermeshing of Inuit and western epistemologies. While Inuit ways of knowing and being have persisted, flourished, and creatively adapted to contemporary resource development controversies, they do so largely by conforming to western norms and knowledge systems.

abstract: M.E.S.


title: Efficient Switched-Capacitor Converters

contributor:
Jain, Praveen
Electrical and Computer Engineering

subject:
Power Electronics
DC-DC Converters
Switched-Capacitor Converters

abstract: Switched-capacitor (SC) power converters are a class of converters comprised entirely of capacitors and switches. These converters contain no bulky magnetic components and are well suited for miniaturization and silicon integration. In this thesis, a comprehensive framework for the design and analysis of efficient, high-performance switched-capacitor DC-DC converters is presented. A precise, curvature-based averaged modelling technique is first proposed. The generalized technique provides a complete characterization of the converter at all steady-state operating conditions. From this model, a simple and accurate expression for the output impedance is derived. The technique is applied on a number of SC converter topologies and compared with existing steady-state models. An approach to model the dynamic behaviour of SC converters based on the generalized state-space averaging method is also described and demonstrated on a conventional SC converter. Furthermore, a procedure to determine the attainable ideal conversion ratios of any SC converter structure is presented. This procedure is applied on a generalized SC structure and the performance limits of multiphase switched-capacitor DC-DC converters are examined. Based on these results, a novel multiphase SC converter structure with variable-gain is proposed. The converter utilizes an optimized switching configuration with an increased number of attainable ideal conversion ratios, for the given number of capacitors and phases. This property allows the converter to maintain high efficiency across a wide range of operating conditions while reducing size, cost and switching losses. Finally, an integrated implementation of the proposed SC converter is designed, analyzed, and tested. The converter generates a regulated 3.3 V output from a 2.6–5.5 V input at up to 165 mA of output current and is fabricated using 0.35 µm CMOS technology. Details on the implementation are provided, including methods to drive and control the integrated converter. The simulated and experimentally measured performance of the circuit is presented and compared with existing converters.

abstract: PhD