title: Functional MRI Investigation of the Neural Basis of Human Pain Processing in the Brainstem and Spinal Cord; Descending Regulation and Chronic Pain

contributor:
Stroman, Patrick
Biomedical and Molecular Sciences

subject:
fMRI
Neuroimaging
Human
Pain
Chronic
Brainstem
Spinal cord
Expectation
Fibromyalgia
Provoked vestibulodynia

abstract: Pain is a complex experience that includes sensory components, descending pain modulation, and cognitive and emotional effects. A combination of any or all of these effects may be altered in chronic pain conditions. The objective of this thesis was to investigate how network connectivity is altered during the expectation and experience of pain in previously established brainstem and spinal cord pain regulation and resting-state networks, and then compare this to data from groups with fibromyalgia (FM) and provoked vestibulodynia (PVD). FM and PVD are two chronic pain conditions disproportionately affecting women, the underlying mechanisms of which are still poorly understood. The thesis consisted of three main projects. The first study in healthy volunteers compared previously observed resting state fluctuations in the brainstem and spinal cord to connectivity changes observed during the expectation of a predictable noxious stimulus and showed that some of the observed variations seem to be specific to the expectation of pain. Building on this data, the next study then compared a group of women with fibromyalgia with a group of healthy individuals during the expectation and experience of a noxious stimulus in order to better understand the neural processes underlying heightened pain sensitivity in FM. These results showed that pain processing is altered in the brainstem/spinal cord in FM during the expectation and experience of pain in specific ways. The differences in pain processing in FM suggest that the altered pain processing in this condition may be linked to a combination of changes in pain modulation and autonomic regulation networks. The last study then compared a group of women with FM and a group of women with PVD with a group of healthy individuals in order to explore how pain processing is altered at the level of the brainstem/spinal cord in chronic pain as well as what elements of pain modulation during the expectation and experience of pain are unique to each chronic pain condition. These results revealed important differences between potential underlying mechanisms of FM and PVD and help to characterize how brainstem/spinal cord networks are altered in chronic pain.

abstract: PhD


title: The Inescapable Quest for Happiness: Exploring How the Ideology of Happiness Shapes the Contemporary Consumer Marketplace

contributor:
Handelman, Jay
Business

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.

rights: Attribution-NonCommercial-NoDerivs 3.0 United States

subject:
Marketing
Marketplace
Happiness
Ideology
Heterotopia
Consumption culture

abstract: This paper draws attention to the ideology of happiness and examines how it structures a marketplace. The quest for happiness has an extensive presence in contemporary Western culture (Burnett 2012) and is ubiquitous in the context of the marketplace. Prior happiness research conceptualizes happiness as a positive psychological state, emphasizing individuals’ experience (Layard 2005; Thin 2014; Veenhoven 2015). Building on the sociology literature (Cabanas and Illouz 2019; Davies 2015), this study posits that happiness can also be understood as an ideology associated with different values and cultural meanings. Drawing on Foucault’s concept of heterotopia (Foucault and Miskowiec 1986), this study shifts the focus away from the individual experience of happiness to a cultural level of understanding, exploring the following question: How does the ideology of happiness in contemporary consumer society inform the actions of consumers and producers? Using a qualitative investigation, this study contributes to the marketplace literature by investigating the ideological nature of happiness. The findings highlight four happiness discourses that interact in the marketplace and reveal how consumers and producers negotiate these different and contradictory cultural discourses.

abstract: PhD


title: The Effect of Heat Treatment on Nickel-based Oxide Dispersion Strengthened (ODS) Alloy

contributor:
Yao, Zhongwen
Mechanical and Materials Engineering

subject:
Oxide dispersion strengthening
Gamma prime precipitate
Oxide particle
Transmission Electron Microscopy

abstract:
Nickel-based oxide dispersion strengthening (ODS) alloys are promising materials mainly used for aerospace industries, due to their advantages such as excellent strength and oxidation resistance up to 1100oC. The studying of Ni-based ODS is significant for nuclear reactors especially for materials exposed to high temperature and corrosion environments which cannot be achieved by Fe-based ODS alloys.
The purpose of this project is to study the effect of heat treatment on the microstructure as well as to determine its influence on mechanical properties. Nickel ODS with composition Ni-15Cr-4Al-3W-0.8Hf-1Y2O3 has undergone two different manufacturing procedures, namely Alloy A and Alloy B. Their microstructure, size as well as the distribution of oxide particles and gamma prime (denote as γ’) precipitates were studied and compared by TEM. Then the mechanical properties are determined through tensile and hardness testing. Alloy A is the as-HIPed condition whereas Alloy B has gone through additional solution heat treatment and aging. The degree of strengthening is highly dependent on the size of oxide particles, inter-particle spacing, oxide/matrix interface structure and distribution of γ’ precipitates. Thus, this thesis studied in detail on how they affect the mechanical strength through hardness and tensile testing. After heat treatment, the average size of oxide dispersoids decreased from ~9-13nm down to ~5-6nm, and γ’ precipitates reduced from 77nm to 42nm. Hardness of 5.4GPa, 4.3GPa and elastic modulus of 171GPa, 164GPa obtained for Alloy A and Alloy B respectively under room temperature. The performance of Alloy A from tensile test reached the highest yield strength with a value of 687MPa at room temperature, which corresponds well with the hardness results. The size, distribution of oxides and γ’ are the main factors contributing to the strength of the alloy. Therefore, it is important to carefully control those variables by applying appropriate heat treatment parameters.

abstract: M.A.Sc.


title: Phosphorus and Oxygen Dynamics between Fall and Spring Turnover Events in a Small Canadian Shield Lake

contributor:
Boegman, Leon
Civil Engineering

subject: Ice-covered lakes

subject: Fall turnover

subject: Spring turnover

subject: Dissolved oxygen

subject: Photosynthetic dissolved oxygen production

subject: Internal phosphate cycle

abstract:
In dimictic lakes, the stable density stratiﬁcation during summer and winter inhibits vertical mixing of nutrients and oxygen. This favors the development of hypolimnetic hypoxia, which degrades cool-water fish habitat and enhances nutrient mineralization and diffusion from the sediments.  Fall turnover began once the entire water column become nearly isothermal (within 0.4 °C) at the deepest point of the lake and continued to the onset of winter stratification. Similarly, spring turnover began when the water column became nearly isothermal (within 0.4 °C) and continued until the average water column temperature reached 4.0 to 4.5 °C. Fall and spring turnover events, therefore, provide a crucial bi-annual link between surface and bottom waters. Long-term field observations were supplemented with output from a three-dimensional numerical model, to better understand the hydrodynamics of turnovers and associated dissolved oxygen (DO) and orthophosphate (PO4) dynamics within a small temperate lake during 2011 to 2020. Mid-basin convection contributed the most to turnover events. During fall turnover, wind shear only mixed the upper 35% of the surface mixed layer, with convection acting to deepen below. During spring turnover, ice-cover sheltered the lake from wind, causing convection to be the only process occurring and lengthening the turnover duration (~51 days) compared to fall (~13 days).
Photosynthetic production was modeled to contribute 92% of the total dissolved oxygen (DO) input to the lake, the remaining 8% was from atmospheric exchange. Of the DO production, 41% occurred under ice with a potential to contribute 17±11% of the hypolimnetic DO saturation deficit at spring turnover. The occurrence of spring turnover depended on the winter conditions. Warm winters caused a weak inverse stratification that shortened the deepening of the convective mixed layer (CML) under the ice and inhibited spring turnover induced mixing of DO into the hypolimnion. Conversely, cold winters caused an inverse stratification in which watercolumn became isothermal after the CML deepened and removed the stratification. Then, the incoming heat from the surface caused large vertical convections (spring turnover). Severe winters form a very strong inverse stratification that limits the effectiveness of spring turnover.
Mineralization was the main PO4 source producing with 77-98% of the annual internal load. The remaining PO4 (2-23%) was from anoxic sediments. Fall turnover upwelled the trapped PO4 from hypolimnion into the photic zone where it could initiate the spring algal bloom. The bloom was postponed because phytoplankton was mixed to depth with fall turnover mixing events, where their growth was light limited until the seasonal increase in solar radiation in spring.

abstract: PhD


title: Multivariate Hilbert Polynomials For Smooth Projective Toric Varieties

contributor:
Smith, Greg
Mathematics and Statistics

subject: Mathematics

abstract: Generalizing Hilbert polynomials for varieties embedded in projective space, we develop the theory of multivariate Hilbert polynomials for varieties embedded in a smooth projective toric variety. These polynomials can be understood either as an Euler characteristic, or as a vector partition function. We give a characterization of toric projective bundles via local cohomology. We use this characterization to show that, for smooth projective toric surfaces, the multivariate Hilbert polynomial of the Cox ring is reducible if and only if the Picard rank of the surface is less than or equal to 2. For smooth projective toric varieties of dimension greater than 2, we investigate the connection between reducibility of the Hilbert polynomial of the Cox ring, and the splitting of the fan of the variety.

abstract: PhD


title: The Useable Past: History and Collective Identity in Nova Scotia, 1835-1920

contributor:
Carson, James
History

subject:
Nova Scotia
Local History
Firsting and Lasting
Settler Colonial Studies
Loyalism
Liberalism
T.B. Akins
Beamish Murdoch
Joseph Howe
T.C. Haliburton
Nova Scotia Historical Society

abstract: This dissertation examines the writing of history in Nova Scotia between 1835 and 1920, beginning with the promotional loyalist works of Thomas Chandler Haliburton and ending in the early twentieth-century when tourism history emerged and marked an abrupt break from how historians had represented the province’s past over the previous several decades. Across more than three quarters of a century, the production of local and provincial histories enabled local elites to craft stories about the emergence of modernity in Atlantic Canada that, in turn, underpinned explicit arguments about who counted and who did not as modern Nova Scotians. The connection between historiographical evolution and colonial identity creation was so close that one could argue that in reconstructing their past, elite Anglo-Nova Scotians narrated both the past they wanted and the future they dreamed.

abstract: PhD


title: Essays on Human Capital, Inequality and Growth

contributor:
Keay, Ian
Abbott, Brant
Economics

subject:
College Dropout
Canadian Housing Market
Inequality
Newfoundland Economic History

abstract:
The first chapter studies heterogeneity in rates of college noncompletion in the United States. College noncompletion rates exhibit considerable heterogeneity along the lines of student ability and family resources. I study the origins of this heterogeneity in college noncompletion risk and its implications for productivity and the distribution of human capital. In general, we should expect noncompletion rates to rise as education subsidies become more generous. This occurs because 1) as subsidies become more generous, the average ability of enrollees falls, and 2) resulting lower skill premia drive noncompletion decisions by marginal students. Policy experiments show that although subsidy expansion increases human capital attainment, it is dominated by a merit-based subsidy. My findings suggest that the ``crisis'' of college noncompletion could be addressed with policies that affect students' work-study decisions.

The second chapter studies the contribution of housing to the evolution of wealth and inequality in Canada during the recent housing boom. Combining data on household assets and quality-adjusted house prices with a portfolio share model, we estimate housing demand, mortgage demand and net worth in the absence of a housing boom. Increased wealth from the housing boom for low-earning and young households has been driven by an increase in the quantity of housing they own, whereas appreciation has been more important for older, affluent households. These effects vary considerably across cities. We also find that the housing boom in Canada has mitigated both wealth inequality and inequality of owner-occupied housing between high and low income households, as well as young, middle-aged, and older households.

The third chapter studies the comparative development of settlements in Newfoundland, Canada after the incorporation of local governments, beginning in the 1950s. Earlier settlements, from the period of Admiralty Rule, were established with essentially no state, whereas later settlements, from the Dominion of Newfoundland, were established with only a centralized government. My results suggest that earlier settlements declined less slowly after incorporating local governments compared to more recent ones. I attribute this result to the lack of a state in early settlements crowding in the social capital that supports long-run institutional development.

abstract: PhD


title: Knowledge Calibration and Consumer Interpretations of Ambiguous Advertisement Information: Implications for Education, Public Policy, and Marketing Strategy

contributor:
Dacin, Peter A.
Business

subject:
Knowledge Calibration
Consumer Education
Consumer Knowledge
Ambiguity
Misleading Advertising
Public Policy
Advertising Claims
Marketing

abstract: Consumers and marketers often assess their cognitive activities: they judge what, and how much they know, remember, learn, and comprehend. The accuracy of these metacognitive judgments is important because they monitor, and ultimately mediate one’s level of cognitive performance. In turn, these judgments also affect the quality of decisions and choices that are based on that information. I conceptualize this degree of metacognitive accuracy as the degree of knowledge calibration. Despite over three decades of research, the knowledge calibration marketing literature has yet to be synthesized into a conceptual framework. The first aim of this dissertation is to provide a systematic understanding of knowledge calibration theory in marketing. This integrative review begins by developing a comprehensive knowledge calibration definition, as well as a typology of methods for studying this concept. Building on this conceptual foundation, I then present a set of insights into knowledge calibration’s antecedents and consequences. Finally, I illuminate important research questions that remain unanswered. Drawing on this understanding of important calibration questions to answer, this dissertation turns to explicating the critical role that knowledge calibration plays in moderating how consumers respond to advertising claims that omit relevant product information. We know from prior work that these types of claims increase consumer perceptions of ambiguity regarding their meaning. Interestingly, advertising research finds that consumer attempts to interpret this ambiguity frequently persuade, and even mislead them into forming positive product beliefs. In seven experiments, I demonstrate that when consumers’ perceived and objective product knowledge are accurately calibrated, advertising claims which omit relevant information are less persuasive, and are perceived to be more misleading than claims which include that information. These effects occur because those who possess a calibrated knowledge negatively interpret what they do not know about products that are advertised with ambiguity-eliciting claims. By developing this framework, I contribute to knowledge calibration, consumer education, and advertising theory. This research also offers implications for education program design, public policy on advertising deception, how consumers cope with marketplace misinformation, and when marketers’ strategic omission of information from their persuasive communications will be met with backlash.

abstract: PhD


title: PROCESSING AND PROPERTIES OF THERMOPLASTIC COMPOSITES CONTAINING GRAPHENE NANOPLATELETS

contributor:
Kontopoulou, Marianna
Chemical Engineering

subject:
Graphene nanoplatelets
Graphene
Thermoplastic composites
Nanocomposites
Graphite
Graphene polyamide composites
Graphene polypropylene composites
Polypropylene foams
Composite foams
GNP
Exfoliation
Compatibilized composites
Graphene nanocomposites
Thermoplastic foams
Fused deposition modeling
Material extrusion
Interfacial adhesion
Interfacial diffusion

abstract:
The objective of this thesis is to develop thermoplastic composites containing expanded graphite (EG) and graphene nanoplatelets (GNPs) using an industrially-relevant melt compounding method. Improvements in the mechanical, electrical, thermal, rheological properties were examined and interpreted based on filler dispersion and composite morphology.
Polyamide (PA) composites containing well-dispersed, in-situ delaminated GNPs were prepared by melt compounding. Results from scanning electron microscopy, transmission electron microscopy and 3D tomography showed good dispersion of GNPs, which is attributed to the similar surface energies of PA and GNPs. The electrical, thermal, and mechanical properties of the composites were investigated: the electrical percolation threshold was attained at 1.9 vol.% GNPs; the thermal conductivity of 2.5 W‧m-1‧K-1 was obtained at 8 vol.% GNPs; the flexural modulus was 5057 MPa at 15 vol.% GNPs. The impact strength of 64 J/m was achieved by adding an elastomeric impact modifier at 40 wt.%.
GNPs with a specific surface area of 400 m2/g were prepared from EG by thermomechanical exfoliation. A compatibilization approach involving the functionalization of polypropylene (PP) with pyridine moieties was implemented to disperse the fillers in PP. The electrical percolation thresholds were 6 vol.% and 10 vol.% in the compatibilized PP-EG and PP-GNP composites respectively; the maximum electrical conductivity was 10-1 S/m. The GNPs increased the flexural modulus by as much as 95% compared to the unfilled PP, whereas the impact strength remained unaffected up to 10 wt.% GNPs. The EG and GNPs promoted heterogeneous nucleation in the foaming of PP using nitrogen as a blowing agent. The foams had cell densities in the order of 107 cells/cm3, fine cellular structure in the range of 20 μm – 60 μm in diameter, and a five-fold increase in the compressive modulus compared to the neat PP foam.
Finally, this thesis examines the effects of the thermorheological properties of PP blends and composites containing GNPs on the material extrusion characteristics, the interfacial adhesion, and the mechanical properties of the built structures. An elastomeric ethylene-octene copolymer was added at 20 – 40 wt.% to the formulations to improve the interfacial adhesion. The alignment of GNPs during processing resulted in anisotropy in thermal and flexural properties.

abstract: PhD


title: Potential of a laccase-1-hydroxybenzotriazole system from Trametes versicolor to degrade per- and polyfluoroalkyl substances

contributor:
Kueper, Bernard
Weber, Kela
Civil Engineering

subject: Biodegradation PFAS Laccase Mediator Fungi

abstract:
Per- and polyfluoroalkyl substances (PFAS) are a group of chemicals used for consumer and industrial applications due to their favourable properties to provide resistance to oil, grease, and water. PFAS are persistent organic pollutants being found globally in environmental matrices at increasing concentrations due to their recalcitrance. Current degradation based treatments for PFAS in groundwater or soil have seen some, but limited success. Due to the toxic effects related to PFAS exposure, finding a successful option to degrade PFAS in the environment is a pressing area of research.
In the current study the biodegradation potential of five PFAS in a laccase and laccase-1-hydroxybenzotriazole system with either copper (II) sulfate or citrate-phosphate buffer was evaluated. The laccase evaluated in this work originated from a white rot fungi Trametes versicolor (TV) which had not previously been evaluated for PFAS degradation potential. The five PFAS evaluated were perfluorooctanoic acid, perfluorooctane sulfonic acid, 6:2 fluorotelomer carboxylic acid, 6:2 fluorotelomer sulfonic acid, and the ammonium salt of hexafluoropropylene oxide dimer acid (GenX). 7:3 fluorotelomer carboxylic acid was evaluated as an additional PFAS in the citrate-phosphate buffer experiments. Aqueous PFAS concentrations of 0.75 parts per million (ppm) were evaluated, along with a study for 6:2 fluorotelomer sulfonic acid biodegradation at 2 parts per billion (ppb). It was shown in the citrate-phosphate buffer that the two fluorotelomers with a 6:2 structure were degradable in the laccaseTV system and the fluorotelomer with the 7:3 structure was degradable in the laccaseTV-1-hydrobenzotriazole system illustrating the likely preference for different degradation pathways based on chain length. At the lowered concentration (2 ppb) the 6:2 fluorotelomer sulfonic acid was able to degrade at a faster rate than 0.75 ppm, likely a result of a higher ratio of enzyme to PFAS. The perfluorooctanoic acid and perfluorooctane sulfonic acid were not transformed in the laccaseTV system, yet were previously demonstrated to degrade with laccase originating from Pleurotus ostreatus, showing that the source of laccase influences the system. GenX was shown to be resistant to degradation in all tested systems indicating that perfluoroether chains cannot undergo biological degradation by laccaseTV under the tested conditions.

abstract: M.A.Sc.


title: Testing Associations Between Impulsivity Facets and Suicidal Behaviour Among Young Adults

contributor:
Stewart, Jeremy
Psychology

subject:
Impulsivity
Suicide
Young Adults
Suicidal Behaviour
Sex differences

abstract: Suicide is the second leading cause of death among young adults in Canada (Public Health Agency of Canada, 2019). Impulsivity is one of the most widely studied correlates of suicidal behaviours. However, most studies to date have treated impulsivity as a homogenous construct, masking potential unique associations between specific subdomains of impulsivity and suicide-related outcomes. Further, sex differences in suicidal behaviour rates have been identified, such that females have greater rates of non-lethal suicide attempts than males; but the processes that facilitate these differences are not yet well understood (Polewka et al., 2004; Mościcki, 1994). To address these gaps, I recruited 117 young adults (18-24 years old) who endorsed suicidal thoughts and/or behaviours within the past year. All participants completed a series of questionnaires and behavioural tasks that measured different state and trait impulsivity facets. The study was completed while on Zoom with a trained lab member. Using a series of negative binomial hurdle models, I found that among ideators, lack of premeditation (acting without thinking), was significantly associated with an increased likelihood of endorsing a previous suicidal behaviour (aborted, interrupted, and suicide attempts), and the strength of this association was not significantly moderated by sex. Moreover, in an exploratory analysis using a series of ordinal regressions, I found that deficits in prepotent response inhibition were significantly associated with more distal suicidal behaviours (i.e., lifetime) when compared to past year and past month suicidal behaviours. This work has significant implications both theoretically and clinically, and ultimately aims to inform enhanced suicide prevention measures.

abstract: M.Sc.


title: Automatic Distribution and Cloud-Native Deployment of Executable Component and Connector Models

contributor:
Dingel, Juergen
Computing

subject: model-driven mdd models deployment automation software containers docker kubernetes uml-rt

abstract:
Model-driven development (MDD) is a software development paradigm that advocates the use of models as the primary artifacts rather than source code. Through abstractions, automation, and analyses, MDD promises higher-quality software at a lesser cost. MDD is widely utilized in the design and development of real-time and embedded (RTE) systems, and many MDD tools in that domain have a proven track record. Conversely, MDD support for distributed systems based on modern scalable architectures (e.g., microservices) is still in its infancy. While many model-driven development languages for RTE systems adopt concurrent execution semantics (e.g., actor-based), they often offer very limited support for distributed applications.
On the other hand, MDD tools tailored for distributed applications, e.g., Internet of Things (IoT) applications, generally implement a custom distributed runtime system (DRTS) to support their execution. The DRTS shields the application for the underlying deployment infrastructure and mitigates some of the problems associated with distributed deployments such as network delays and failures. Unfortunately, the implementation of a DRTS is not only time-consuming but also platform dependant.
In this thesis, we present an approach for the automatic distribution and deployment of components-and-connectors models (CCMs). Our approach uses the architecture information embedded in CCMs to generate and deploy distributed, microservices-based applications entirely through a model-to-model transformation and with no modification to the language execution toolchain or the need for a custom DRTS. Using UML-RT, a popular MDD language for RTS systems with no support for distributed applications, we show how containerization and container management platforms (e.g., Kubernetes) can effectively substitute a DRTS when the models are treated appropriately.

abstract: PhD


title: Environmental Ethics and Permaculture

contributor:
Smith, Mick Jr
Environmental Studies

subject:
Permaculture
Ethics
Soil
Human-soil relationship

abstract: Industrial agriculture exemplifies a reductionist and instrumental world view that effectively pulls people away from richer, more diverse, and more sustainable relationships to land, thereby distorting wider human-nature relationships. Permaculture, as a term and social movement, was envisaged as a technical and philosophical response to this situation, one that might foster real change. This thesis addresses the limits and possibilities of permaculture, especially in terms of its philosophical assumptions and through the tangible lens of how soil is understood and engaged within various forms of permaculture. The thesis highlights a tension between the ways in which permaculture often enables people to be physically back in the land whilst still sharing some aspects of industrial agriculture’s anthropocentric ideology and impeding people from spiritually and ethically reconnecting to soil or a broader nature. It suggests that, despite its advantages we need varieties of permaculture that require deeper and more ethical understandings and conversations with soils as diversely creative and living matrixes.

abstract: M.E.S.


title: A Systematic Review and Meta-Analysis of Exercise Interventions and Use of Exercise Principles to Reduce Fear of Falling in Community-Dwelling Older Adults

contributor:
Auais, Mohammad
Rehabilitation Science

subject:
Fear of Falling
Older adults
Exercise

abstract:
Fear of falling (FOF) contributes to activity restriction and increases fall risks and institutionalization among older adults. Exercise interventions are associated with a reduction in FOF. Adhering to exercise principles and adopting proper exercise parameters are fundamental to optimizing the effectiveness of exercise interventions. The objectives of this thesis were to describe FOF exercise interventions in community-dwelling older adults to inform future programs, evaluate the extent to which these interventions followed the exercise principles and reported exercise parameters, and finally quantify the effect of these interventions on reducing FOF.
Randomized controlled trials (RCTs) of FOF exercise interventions in older adults (≥65 years) were identified from MEDLINE, Embase, PsycINFO, and CINAHL databases from inception to 2020. Two reviewers independently screened and assessed the relevant literature, and a third reviewer was engaged to resolve any conflicts. The methodological quality of RCTs was assessed using the PEDro scale. The qualitative data were narratively synthesized, and a random-effect model was used in the meta-analysis. Sensitivity analyses were carried out to examine the impact of trials with small sample sizes and a high risk of bias on the findings.
Seventy-five RCTs were included in this review. Most trials with a significant effect on FOF used multicomponent exercises and group-based interventions, moderate intensity, three-times-per-week frequency for 12 to 16 weeks, and 30 to 60 minutes for each exercise session. With regard to reporting exercise principles, specificity was reported in 92% of trials, progression in 72%, reversibility in 32%, overload in 31%, diminishing return in 21%, and initial value in only 8% of trials. For exercise parameters, 97% of RCTs reported exercise type, 89% reported frequency, and 85% reported time. Only 25% of trials reported the intensity of exercises. The pooled effect of exercise interventions on FOF reduction among all included studies was a standard mean difference of -0.34 (95% CI = -0.44 to -0.23). The sensitivity analysis showed that the pooled effect size decreased after removing trials with small sample sizes (-0.25; 95% CI =  0.37 to  0.13) and with fair methodological quality (-0.22; 95% CI = -0.36 to -0.8), but the results were still significant.
This study showed a significant small-to-moderate effect size of exercise interventions in reducing FOF among community-dwelling older adults. Most exercise principles and the intensity of exercises were not adequately reported in included trials. These inadequate reports could undermine efforts to examine the optimal dosage for exercise prescription. Researchers must give more attention to designing and reporting components of therapeutic exercise programs to facilitate evidence-based practice.

abstract: M.Sc.


title: Study of TaC Supported Ir-Based Oxygen Evolution Reaction Electrocatalysts Synthesized by Surfactant-Mediated Method

contributor:
Peppley, Brant A
Chemical Engineering

subject:
OER Electrocatalyst
Surfactant-Mediated Method
OER Support
PEM Water Electrolysis

abstract:
The physical and electrochemical properties of Tantalum carbide (TaC) as a potential support for oxygen evolution reaction (OER) electrocatalysts were investigated. It was first ball milled for 7 and 14 days in order to decrease the particle size and increase the surface area. The larger the surface area of a support, the better the dispersion of the electrocatalyst on the support. This implies a larger number of available active sites. The TaC that was ball milled for 14 days showed smaller particle size and larger surface area in comparison with that which was ball milled for 7 days and unmilled TaC. The long term electrochemical stability of the ball-milled TaC was evaluated under OER conditions. The ball-milled TaC was found to be a promising support for OER electrocatalysts in order to reduce the loading of precious metal.
Unsupported and TaC supported Iridium-based electrocatalysts were synthesized via a surfactant-mediated method. The advantage of this method is that no heating is required. The synthesized electrocatalysts were analyzed using physical, chemical, and electrochemical characterization methods to see the effect of the ball-milled TaC on the performance of the Ir-based electrocatalyst. The synthesized unsupported electrocatalyst consisted of 1.8 nm particles. Both the unsupported and supported electrocatalysts were a mixture of Ir0, Ir+3 and Ir+4 oxidation states. It was observed that due to less agglomeration and better dispersion of the supported electrocatalyst on the TaC support, the surface area of the supported electrocatalyst was larger than the unsupported electrocatalyst. Electrochemical properties of the electrocatalysts were studied in a 3 electrode system. The supported electrocatalyst showed larger voltammetric charge and mass activity, and better durability compared to the unsupported electrocatalyst. The supported electrocatalyst also showed lower charge transfer resistance at the end of the long-term stability test.
By supporting the Ir-based electrocatalyst on the ball-milled TaC, the Ir loading was decreased and the utilization of Ir for OER electrocatalysis was enhanced.

abstract: PhD


title: Self-Supervised Near-to-Far Learning for Terrain-Adaptive Off-Road Autonomous Driving

contributor:
Surgenor, Brian
Marshall, Joshua
Mechanical and Materials Engineering

subject:
Robotics
Computer vision
Autonomous vehicles

abstract: Autonomous vehicles are an increasingly important tool for exploring unknown off-road environments where navigation decisions must include considerations of terrain traversability, unlike in urban environments that have engineered roads. In this thesis, a new self-supervised method is proposed for prioritizing traversable terrain while autonomously navigating a vehicle to a goal position in an unknown off-road environment. Leveraging the colour discriminant bias of off-road terrain types, and using images from a vehicle-mounted camera, a homography that maintains the real-world planar layout of the terrain is employed to cluster terrain types by colour and autonomously register corresponding traversability characteristics such as roughness and slip for terrain-adaptive navigation. As it navigates the vehicle, the algorithm also generates training images for use in contemporary end-to-end navigation schemes. Compared to the existing expert-guided near-to-far approaches, the test results demonstrate the higher autonomy introduced by the proposed approach for navigating off-road environments with unknown traversability characteristics, and highlight its fit to contemporary supervised semantic segmentation schemes that require foreknowledge of traversability characteristics, are limited by insufficient data, and suffer significant class imbalance and poor cross-domain performance. Finally, the effectiveness of non-discretionary self-supervised image labelling is discussed.

abstract: PhD


title: The Postwar Debate over Collaboration in Vichy

contributor:
Pugh, David
Cultural Studies

subject:
France
World War 2
Second World War
Collaboration
Vichy
Resistance
Germany
History
Historiography
Paxton
Aron
Laborie

abstract: This thesis is about two histories, the history of the Vichy regime in France between 1940 and 1944, and the evolution of postwar memory and scholarship about Vichy until today. The objective of this research is to investigate the evolving conceptual interpretation of collaboration as it happened in France during the Second World War. This historiography primarily examines the perspectives of scholars, historians, and French civil society in the postwar era with the aim of investigating how they responded to the memory of the Occupation, particularly on the topic of collaboration. I chose to focus on three periods, and three books which were particularly impactful at the moment of their publication: 1945-1965 through the work of Robert Aron, 1954-1970s through the work of Robert Paxton, and the 1980s through the work of Pierre Laborie. The postwar debate over Vichy continues to follow familiar political fault lines between the left and the right, with some far-right factions continuing their attempt at defending the actions of those who chose to collaborate. For some conservatives, particularly in the late 1940s and 1950s, condemning Vichy could only be done in so far as it didn’t compromise their postwar agenda. Additionally, this condemnation couldn’t be at the benefit of communists and the left. I also argue that while there is still much to learn on the history of Vichy, the major debates have been settled by historians. Today, when some wish to instrumentalize the memory of Vichy to further their political agendas, we ought to differentiate historical revisionism from what constitutes an honest debate over the history of this difficult period.

abstract: M.A.


title: Converting lignocellulose feedstock into potential replacements for petroleum-derived products

contributor:
Jessop, Philip
Chemistry

subject:
Lignocellulose
Biomasss conversion
HMF
Hydroxymethylfurfural
Lignin pyrolysis oil
Humins
Jet fuel
Renewable energy

abstract:
Biomass can be used as a renewable energy source to reduce the over-reliance on fossil fuels. Lignocellulose, which is non-edible and the most abundant biomass in the world, comprises two carbohydrate polymers (cellulose and hemicellulose) and one aromatic polymer (lignin). This thesis examines work done to convert lignocellulose biomass to liquid fuels and solvents that are currently derived from fossil fuels.
The work is mainly divided into two sections. In the first section, the attempts to make transportation fuel range alkanes (C8-C22) using hydroxymethylfurfural (HMF) oligomers are described. The second section of the thesis explains the attempts to synthesize cyclohexyl methyl ether mixture from lignin to replace fossil fuel derived solvents.
Under acidic conditions, HMF, a compound obtained by processing carbohydrate polymers, polymerizes to form an insoluble polymer called humin. In this work, oligomerization of HMF has been used as an opportunity to increase the carbon chain length of HMF. Simultaneous oligomerization and hydrodeoxygenation of HMF were shown to make long-chain alkanes (>C9). Completion of hydrodeoxygenation was confirmed by 1H NMR spectroscopy. According to mass spectroscopy, long chain alkanes up to about 600 m/z were present. Alkanes from C9-C18 were analyzed by GC-MS. Different straight, branched, and cyclic alkanes with C10-C12 were observed. From these n-dodecane had the highest concentration. Most of the major peaks were consistent with the alkanes obtained through dimers from oligomerization and self-condensation reactions of HMF.
A mixture of cyclohexyl methyl ethers was prepared from Kraft lignin pyrolysis oil for use as a biomass-derived aliphatic solvent. Using Kamlet–Taft solvatochromic parameters, it was determined that the solvent mixture is somewhat more basic and polar than cyclopentyl methyl ether. Neither the biomass- derived solvent nor pure cyclohexyl methyl ether formed any detectable peroxides in 12 weeks of exposure to air, even though THF forms peroxides rapidly under such conditions. This mixture can be used as a biomass-derived aliphatic ether solvent and as a potential replacement for THF, dioxane, ethyl acetate, acetone and 2-butanone.

abstract: M.Sc.


title: Radial Voting Based Keypoint and 6DoF Pose Estimation

contributor:
Greenspan, Michael
Electrical and Computer Engineering

subject: 6DoF pose

abstract: A novel keypoint voting scheme named radial voting based on intersecting spheres is proposed. It is more accurate than existing schemes and accepts a relatively smaller set of sparse keypoints. Radial voting forms the voting stage of the proposed RCVPose method for RGB-D based 6 DoF pose estimation of 3D objects. A CNN is trained to estimate the distance between the 3D point corresponding to the pixel of the depth field, and a set of $3$ sparse keypoints defined based on the bounding box of the object. At inference, a discrete sphere with the radius of the estimated distance is rendered, centered at each corresponding 3D point. The voxels on the surface of these spheres vote to increment a 3D accumulator space, the peak of which indicates the estimated keypoint location. The proposed radial voting is more precise than existing vector and offset voting, and is also robust to sparse keypoints and target object scale. Experiments demonstrate RCVPose to be highly accurate and competitive, achieving state-of-the-art results on the LINEMOD 99.7% and YCB-Video 97.2% datasets, and notably scoring +7.9% higher than previous leading methods on the challenging Occlusion LINEMOD 71.1% dataset.

abstract: M.A.Sc.


title: Comprehensive study on the mechanical properties of δ-zirconium hydride grown in a Zr2.5%Nb matrix

contributor:
Daymond, Mark R
Mechanical and Materials Engineering

subject:
Nuclear materials
Zirconium Hydride
Zirconium alloys
Mechanical properties

abstract:
Zirconium alloys are used in the nuclear industry because of low neutron capture cross-section, appropriate mechanical properties, and corrosion resistance. In-reactor, the zirconium components undergo hydrogen pick-up, mainly due to corrosion occurring along the component and with the steel end-fittings. When the hydrogen reaches a threshold terminal solid solubility, the precipitation of zirconium hydride occurs. This thesis investigates the mechanical properties of this hydride precipitate, under different conditions and using different techniques to assess those properties.

After the introductory Chapters (1 and 2), Chapter 3 includes details regarding the methodology used in subsequent chapters.

Chapter 4 presents the mechanical properties (at room (RT) and high temperatures (HT)) of the δ-zirconium hydride grown in two different structures (rim and blister) using a combination of nanoindentation and modelling. At RT, the measured hardness of the hydride rim was 3.73GPa, while the hydride blister was 3.5GPa. The RT yield strength values obtained via models were 904MPa and 890MPa using one model, and 869MPa and 862MPa with the second, for the rim and blister, respectively. The HT hardness decreased linearly with increasing temperature.

Chapter 5 shows a novel result of the impact of proton irradiation on the hardness of δ-zirconium hydride and Zr2.5%Nb. The true hardness of the δ-zirconium hydride increased from 3.0±0.12GPa at 0dpa, to 4.31±0.35GPa at 0.8dpa, while Zr2.5%Nb increased from 2.53±0.12GPa at 0dpa to 3.03±0.21GPa at 0.8dpa. The yield strength of the δ-zirconium hydride increased from 862MPa at 0dpa, to 1146MPa at 0.8dpa, and the Zr2.5%Nb increased from 662MPa at 0dpa to 850MPa at 0.8dpa. In addition, both materials showed evidence that, up to 0.8dpa, there is still no saturation of irradiation defects.

Chapter 6 investigates the mechanical properties, and the deformation mechanisms, of the δ-zirconium hydride via micropillar compression, and ex-situ TEM investigation. The hydride yield strength obtained from the stress-strain curves was 1084±125MPa. TEM investigation of the deformed micropillar showed the formation of dislocations inside the hydride, characterized as belonging to a typical FCC slip system.

Lastly, Chapter 7 gives a summary of the conclusions, correlations between each chapter, and future work recommendations.

abstract: PhD


title: Energized mass and its application to airborne seeds and sensors

contributor:
Rival, David
Mechanical and Materials Engineering

subject:
unsteady aerodynamics
biologically inspired
bluff body
wind dispersed seeds
distributed sensing
separated flow

abstract: Large-scale flow-tracking measurements require sizeable flow tracers for optical visibility, or the carrying of a sensor payload. As a result of the increased size and mass, the tracers experience an inertial lag, impacting flow fidelity and measurement accuracy, especially in unsteady flow conditions. This thesis approaches the tracer-lag problem through a physics-based modelling framework while also exploring biologically-inspired flow tracers and a non-optical flow-sensing system. For the latter, coupling a low-order correction with improved tracer flow fidelity has potential applications in distributed flow-sensing (non-optical) techniques. The studies in this thesis focus on the development of a novel modelling framework and its application to the gust-response of wind dispersed seeds and flow sensors with inertial measurement units (IMUs). First, the concept of energized mass is introduced and validated as a robust framework for modelling forces in separated flows. Second, the gust response of the milkweed seed, which achieves flight through drag-producing bristles, is characterized and the applicability of the energized-mass approach is examined.  Finally, a proof of concept for a non-optical, IMU-based flow measurement tool is presented, enabled by the energized-mass-based model correction. When combined, these results contribute to the understanding and modelling of unsteady forces, while also providing a step towards improved large-scale flow measurements.

abstract: PhD


title: Death and Self-Identity in the Contemporary Fantasies of Philip Pullman, Garth Nix, and Steven Erikson

contributor:
King, Shelley
English Language and Literature

subject:
Death
Identity
Self-Identity
Pullman
Nix
Erikson
Fantasy
Twenty-First Century
Katabasis
Afterlife
Landscape
Narrative
Dead
Literature
Dante
Homer
Malazan
Old Kingdom
His Dark Materials
Underworld
Hell
Purgatory
The Divine Comedy
Framework
Boundary
Border
Life
Memory
Representation
Personification
Aging
Temporal
Spatiality
mobility
Community
Culture
Threshold
Liminal
Transition

abstract: Death is inevitable yet inherently unknowable in its experience. The possibility of persistence within death lacks evidence but compels the mind. Through imagined narratives we can conceptualize possible experiences of death and afterlife spaces to address the fears and uncertainties associated with death’s unknowability. How death is represented in a narrative work offers a mirror through which to understand socio-cultural norms and dominant ideologies. To better explicate narrative representations of death I identify three possible meta-forms for death: death as a determinate ontological state (in that a self can be dead); a physical space with constituent landscape (in that a self can be in death); or an embodied identity (in that a self can be Death). I apply this framework to contemporary fantasy in case studies of Philip Pullman’s His Dark Materials, Garth Nix’s The Old Kingdom, and Steven Erikson’s Malazan Book of the Fallen to explore how each representation of the three forms of death and their interrelations allows for more nuanced readings of the texts themselves, while also reflecting dominant social perspectives towards death in their period and cultural context. I seek to expose the lines of influence between death forms while offering a traceable continuity from traditional beliefs and classical engagements with the afterlife to contemporary representations. In examining the orientations of self relative to each form of death, the framework opens space for analysing how death itself is altered by identity-driven and spatially-centered assertions of agency. The death found in these case studies is materially-oriented rather than purely spiritual, divorced from strict sacred belief but indebted to their precedent, prioritizes being over acts, and privileges landscape at the core of its experience. These deaths are indicative of a cultural shift towards a secularization of death, reveal a preoccupation with embodiment, and balance a growing tension between increasing individuality and personal agency on the one hand, and a social need for community support and interpersonal relationships on the other. Imagined narratives work to map some of death’s infinite possibility and many forms and I seek to offer a language for their analysis.

abstract: PhD


title: Opportunities for forest-based biorefining to reverse decline in Canada’s forest products sector

contributor:
Mabee, Warren
Geography and Planning

subject:
forest bioeconomy
forest biorefining
public policy
resource policy
forest products
forest sector
forest products manufacturing
forest products markets

abstract:
This thesis explores the impacts of disruptive change drivers on the Canadian forest industry and evaluates the extent to which socio-economic policies can advance or constrain transition to new future directions.
Canada’s forest sector has experienced a substantive disruption. Since 2009, average harvest rates are 44 million m3/year lower than was observed in 2000-2004.  The drop in forest harvest is related to major market changes driven by widespread uptake of the Internet, which reduced the need for printed newspapers dramatically impacting revenues from classified ads; and declines in single-family home construction and corresponding increases in multi-family, multi-storey buildings which has reduced demand for wood building products.
In response, policy initiatives have been launched by Canada’s Federal and Provincial governments.  Policies launched between 2000-2015 were examined through four analytical frameworks drawn from social life-cycle assessment (S-LCA) principles: industry sector; industrial process stage; policy mechanism; and, broad policy domain. The examination identified a shift from industry sector focus towards broader policy goals related to climate change with subsequent reversion to a focus on multi-sector biorefining opportunities.
A specialized tool to model biorefinery implementation - the I-BIOREF application developed by CANMET Energy - is used.  Identified measures are evaluated against three important criteria: required data be available, collection be automated, and the measure be acceptable to key stakeholders.  Three measures, including employment, employment income, and tax filings, meet these criteria.
Impacts of deploying different biorefinery technologies are examined in three case communities - Prince George BC, Thunder Bay ON, and Corner Brook NL - with significant dependence on the forest sector.  Using the I-BIOREF tool, a different biorefinery technology configuration is applied at each site and assessed at different sizes and levels of government support to identify financially feasible configurations.  The resulting analysis illustrates the benefits or pitfalls associated with biorefinery deployment, providing insights both into regional benefits and comparative performance across different configurations.  The analysis suggests that the three socio-economic indicators examined would provide a valuable addition to the I-BIOREF software and be useful for determining the potential impact of possible public policy and program initiatives to support forest biorefining development.

abstract: PhD


title: Towards a Planning-Based Neural-Symbolic Framework for Egocentric Agent Design

contributor:
Liu, Xiaotian
Computing

subject:
Neural Symbolic
Machine Learning
Computer Vision
Egocentric Planning
Partial Obsevability
Embodied Agent

abstract: In the last decade, deep neural networks have given embodied agents many tools that can extract information from environmental data. However, tasks such as reasoning and long-term planning cannot be done effectively using deep neural networks. Symbolic methods, such as automated planning, are still methods of choice for embodied agents in most applications. The integration of a planning system with deep neural networks seems to be the natural next step for embodied agent design. However, many challenges from both the planning and deep learning side need to be solved for such hybrid systems. This work proposes a neural-symbolic framework for constructing embodied agents, capable of semantic navigation, that can take advantage of both neural and symbolic algorithms. The framework uses neural networks for low-level information extraction and automated planners for high-level reasoning. The main challenges our approach addresses are converting traditional pansophical planners to egocentric perspectives and finding the appropriate factored representation for environmental information discovered by such agents. The thesis has two main contributions towards building a neural-symbolic embodied agents. Our first contribution is presenting a method of converting classic pansophical planning problems to egocentric alternatives. Secondly, we propose a spatial semantic graph structure to store environmental information for autonomous object navigation.

abstract: M.Sc.


title: Hybridity and Intersections among Queer Theory, Animal Studies, Child Studies, and Late-Victorian and Edwardian Children’s Literature

contributor:
Cameron, S. Brooke
English Language and Literature

subject:
queer theory
animal studies
child studies
children's literature
Victorian
Edwardian

abstract: This dissertation examines intersections among children, animals, and queerness in late-Victorian and Edwardian children’s literature and the representation of hybrid characters or relationships. Hybridity includes inter-species kinship structures and also physically hybrid bodies or animals performing the human. I argue that human-animal hybridity, through its resistance to binary thinking about the human/animal divide, also leads to instances of queer resistance to heteronormative binaries or ideals, and resistance only gets stronger the further the children move from the adult or human world. Hybridity is most challenging to heteronormative or anthropocentric ideals when the hybridity is accepted or promoted by the animals rather than forced upon them. The animals’ support of hybridity that questions the divide between human/animal also has the potential to challenge other seemingly strict binaries such as male/female or adult/child. This resistance in children’s literature also opens up space for child characters to question adult assumptions about future (hetero)sexuality and expected hierarchies. I analyze instances of human-animal hybridity in Frances Hodgson Burnett’s The Secret Garden (1911), Anna Sewell’s Black Beauty (1877), Kenneth Grahame’s The Wind in the Willows (1908), and finally Rudyard Kipling’s The Jungle Books (1894/1895). Chapter 1 analyzes hybrid kinships in The Secret Garden; Chapter 2 examines the horse as human-animal and animal-machine hybrid in Black Beauty; Chapter 3 explores the male homosocial (and anthropomorphized) animal world in The Wind in the Willows; finally, Chapter 4 examines human-animal hybridity and kinship in The Jungle Books. My dissertation focuses on the shift from the “real” animal in the “real” world, in texts such as The Secret Garden and Black Beauty, to more anthropomorphic animals, in texts such as The Wind in the Willows and The Jungle Books, and worlds that are further removed from the more normative and anthropocentric adult one.

abstract: PhD


title: A novel synthetic method for oxygen-17 labelling of metal-dioxygen complexes

contributor:
Wu, Gang
Chemistry

subject:
Oxygen
Oxygen-17 NMR
Metal-dioxygen complexes
Water electrolysis
NMR
Transition metal complexes
Myoglobin

abstract: This thesis investigates the synthesis of 17O-labelled metal-dioxygen complexes by utilizing 17O2 gas produced from H217O electrolysis as a source of 17O isotopes. Because of the high cost of H217O, a miniature water electrolysis device was built to collect 17O2 gas at a rate of 6.1 x 10-4 mol O2/hr (~15 mL/hr) over water. Two 17O-labelled dinuclear cobalt(III)-dioxygen complexes, [(en)2Co(μ-17O2)(μ-OH)Co(en)2]3+ where en is ethylenediamine (1b) and [(NH3)5Co(μ-17O2)Co(NH3)5]4+ (2b) were successfully synthesized for the first time. Their 17O Nuclear Magnetic Resonance (NMR) signals were found to appear at 242 and 208 ppm for 1b and 2b, respectively. These 17O chemical shifts represent the most shielded values to date for metal-dioxygen complexes. We also discovered that the μ-hydroxo ligand in [(en)2Co(O2)(μ-OH)Co(en)2]3+ can be readily 17O-labelled by exchange with H217O, thus producing [(en)2Co(O2)(μ-17OH)Co(en)2]3+ (1c). We found that the 17O and 1H NMR signals for the μ-hydroxo ligand in 1c are highly shielded ((17O) = -239 ppm and (1H) = -2.43 ppm). Furthermore, we report new 17O NMR data for a 17O-labelled mononuclear metal-dioxygen complex, Pd(PPh3)2(2-17O2) (4b), δiso(17O) = 561 ppm. Lastly, a preliminary investigation of the crystallization and stability of oxymyoglobin (oxyMb) was conducted. Optimal crystallization of oxyMb was observed in a Tris-HCl buffer at pH 6.5 with 75% saturated ammonium sulfate. Optimal storage conditions of oxyMb microcrystals were found in a Tris-HCl buffer at pH 8.5 with 75% saturated ammonium sulfate, where the autooxidation rate of oxyMb microcrystals was determined to be (8.1 ± 0.8) x 10-4  hrs-1 at 253 K, corresponding to t1/2 = 850 hrs. We concluded that oxyMb is a suitable candidate for 17O-labelling via the new H217O-electrolysis route.

abstract: M.Sc.


title: Dark Matter Searches with Germanium and Silicon detectors in SuperCDMS and CUTE

contributor: Physics, Engineering Physics and Astronomy

subject:
Dark Matter
SuperCDMS
CUTE

abstract: The Super Cryogenic Dark Matter Search (SuperCDMS) uses germanium and silicon semiconductor detectors to search for dark matter. Particle interactions with these detectors create observable signals in the form of phonons and electron-hole pair. We apply a voltage bias across these detectors, utilising the Neganov-Trofimov-Luke (NTL) effect to amplify the charge signal into phonons and search for the rare low-energy depositions of light dark matter. In CDMSlite Run 3, my work on a fiducial volume cut was a primary factor in being able to set at-the-time world-leading dark matter limits for WIMPs in the 1.6 to 5.5 GeV range. The Cryogenic Underground TEst facility (CUTE) is a detector testing facility operated at SNOLAB that has been used to test SuperCDMS detectors. One such de-tector is PD2, which when operated at a surface facility set leading WIMP exclusions. My work operating PD2 at CUTE and exploring the backgrounds and capabilities of CUTE using PD2 and other detectors paves the way for SuperCDMS detector testing at SNOLAB.

abstract: PhD


title: Dynamics of Sediment Resuspension and Transport by Fission of Nonlinear Internal Waves Over a Mild Slope

contributor:
Beogman, Leon
Civil Engineering

subject:
Internal wave
Stratified flow
Sediment transport
Resuspension
Bedform
Coastal Engineering

abstract:
Breaking nonlinear internal waves (NLIWs) of depression on boundary slopes drive mixing and mass transport in the coastal ocean. Of the different breaker types, fission is most commonly observed on the mild slopes of continental margins. However, fission on mild slopes has rarely been investigated in the laboratory owing to limitations in flume length. In the present work, a train of NLIWs of depression was generated in an 18.2 m wave flume and shoaled upon a mild uniform slope (S = 0.04). During fission, each NLIW of depression scattered into one or two NLIWs of elevation at the turning point and transformed into a bolus at the bolus birth point (BBP), where the flow separates from the bed and shear instability occurs through the pycnocline. The bolus propagated upslope, decreasing in size until it degenerated by shear and lobe-cleft instability, while losing volume to a return flow in the lower layer. The location of the BBP, bolus propagation length scale, initial size and the number of boluses from each incident wave were parameterized from the wave half-width and the wave Froude number associated with the incident NLIW.
The same experimental facilities were used to investigate sediment transport, as both bedload and resuspension, driven by NLIW fission on the mild uniform slope, which was covered with acrylic sediments. Incipient sediment movement started as bedload under NLIWs of elevation after the turning point. Further upslope, sediments resuspended under the front face of the NLIW of elevation, where bottom currents converged, causing upward flow. The intensity of sediment movement peaked at the BBP. The sediment movement mechanisms were the same for boluses as for NLIWs of elevation, except boluses carried sediments upslope in a quasi-trapped core. Different methods for estimating the bed shear velocity were evaluated and compared with the critical thresholds for bedload and resuspension. The logarithmic law-of-the-wall was best able to predict sediment movement as bedload through the inclusion of the mean horizontal velocity component, and the turbulent kinetic energy method was best able to predict sediment resuspension by considering the ability of fluctuating vertical velocity components to lift sediment.

abstract: PhD


title: A Comprehensive Review on the Applications of Stereography and Stereophotogrammetry in Architectural Documentation

contributor:
Bevan, George
Geography and Planning

subject: Architecture

subject: Graphic documentation

subject: Stereography

subject: Stereophotogrammetry

subject: Built cultural heritage documentation

subject: Built cultural heritage

subject: Architectural documentation

subject: The integration of Stereography and Stereophotogrammetry

abstract: Current efforts in the digital documentation of built cultural heritage focus on producing fully interactive digital surrogates using light detection and ranging (LiDAR) and structure-from-motion (SfM) photogrammetry techniques. These approaches require massive quantities of data in the form of point clouds or input images, along with enormous and difficult-to-share final models. Moreover, these approaches do not capture the architectural character as well as fundamental geometry. Rather than generating fully three-dimensional (3D) models, which is time-consuming and inefficient, stereography provides a potential alternative for graphic documentation. However, stereography has never been used as a heritage deliverable, comparable to architectural photos and technical drawings. Given this fact, this thesis suggests integrating stereography and stereophotogrammetry to allow users to observe stereopairs and record their spatial experiences (i.e., using a phenomenology method) or the architectures' geometry (i.e., using a Cartesian method). In fact, integrating these two approaches will significantly reduce the volume of data required for documentation, allowing for better long-term storage. These combined approaches do not require a digital surrogate and can provide nearly the same information as other documentation methods. In this regard, this thesis presents a comprehensive literature review on integrating stereography and stereophotogrammetry for digital documentation. In addition, some examples of heritage architecture in Kingston, Ontario, have been provided to showcase the gaps in heritage documentation.

abstract: M.Sc.


title: A new Genotyping-in-thousands by sequencing (GT-seq) assay for polar bears (Ursus maritimus): development, validation, and applications

contributor:
Lougheed, Stephen
Biology

subject:
polar bear
non-invasive
GT-seq
faecal
sex-biased
dispersal
monitoring
SNP panel

abstract: Traditional wildlife monitoring approaches are often time-consuming and expensive, and fail to partner with and benefit Indigenous communities. This is particularly relevant for polar bears (Ursus maritimus), which lack contemporary range-wide data on population dynamics, are facing large-scale habitat declines due to climate change, and are of socioeconomic and cultural importance to northern communities. Genetic monitoring using non-invasive samples (e.g. scat) can provide a complement or alternative to traditional methods, but requires novel genetic techniques that are optimized for degraded DNA. Thus, my second data chapter focused on developing, optimizing, and validating a Genotyping-in-Thousands by sequencing (GT-seq) panel of 324 single nucleotide polymorphisms for degraded polar bear DNA. My work demonstrated successful genotyping (>50% loci) for a range of DNA sources, including 62.9% of non-invasively collected scat samples determined to contain polar bear DNA, and that GT-seq data can be reliably used to discern individuals, identify sex, assess relatedness, and resolve population structure in Canadian polar bears. To further expand our understanding of polar bear population dynamics and explore the power of GT-seq, I used this new GT-seq assay in my third data chapter to test for male-biased dispersal in four Canadian polar bear subpopulations and whether this increases with population density. My genetic clustering results indicated some fine-scale genetic structure in females from low-density areas, consistent with male-biased dispersal. In contrast, spatial autocorrelation analyses did not reveal spatial patterns consistent with male-biased dispersal, although were likely limited by poor sampling resolution and geographic scale of sampling. My work confirms that GT-seq provides comparable information and resolution to traditional methods of monitoring, but enables greater cost-efficiency and the use of degraded (e.g. non-invasive) samples. Importantly, I demonstrate the power of GT-seq for sex-biased dispersal evaluation and provide the first of such applications. Overall, I conclude that GT-seq in tandem with community-based monitoring programs may improve temporal monitoring of polar bear populations and Arctic ecosystems, actively provide socioeconomic benefits to northern communities, and serve as a model for inclusive, non-invasive wildlife monitoring worldwide.

abstract: M.Sc.


title: Computational Water Quality Modelling of Western Lake Erie

contributor:
Boegman, Leon
Civil Engineering

subject:
Water quality
Western Lake Erie
AED-GLM
AEM3D-iWQ

abstract:
During the 1970s, harmful algal blooms (HABs) were common occurrences in western Lake Erie. Remediation strategies reduced total P loads and bloom frequency; however, HABs have reoccurred since the mid-1990s under increased system stress from climate change. Given these concurrent changes in nutrient loading and climate forcing, there is a need to develop management tools to investigate historical changes in the lake and predict future water quality. Herein, we applied coupled one-dimensional (1D, AED-GLM) and three-dimensional (3D, AEM3D) hydrodynamic and biogeochemical models to reproduce water quality conditions of western Lake Erie from 1979-2015 and 2002-2014, respectively. For the 1D model, the root-mean-square errors (RMSE) between simulations and observations for water levels (0.36 m), surface water temperature (2.5 ℃), and concentrations of total phosphorus (0.01 mg L-1), phosphate (0.01 mg L-1), ammonium (0.03 mg L-1), nitrate (0.68 mg L-1), total chlorophyll-a (18.74 μg L-1), chlorophytes (3.94 μg L-1), cyanobacteria (12.44 μg L-1), diatoms (3.17 μg L-1), and cryptophytes (3.18 μg L-1) were minimized using model-independent parameter estimation. A sensitivity analysis shows that 40% reductions of total P and dissolved reactive P loads would have been necessary to bring blooms under the mild threshold (9600 MTA cyanobacteria biomass) during recent years (2005-2015), consistent with the Annex 4 recommendation. The 3D model was calibrated/validated in 2008/2009 using temperature, phosphate, total phosphorus, and chlorophyll-a data, with RMSE of 2.77/1.97 ℃, 1.78/5.65, 3.18/9.30, and 1.75/2.84 μg L-1. In addition, the model was calibrated/validated against phytoplankton succession data over 2008-09/2002-14 with RMSE of 2.79-2.67/4.80-4.89 μg L-1 for early diatoms, 0.46-1.67/0.88-2.81 μg L-1 for late diatoms, 0.59-0.83/0.47-0.78 μg L-1 for cryptophytes, 0.59-0.73/0.64-0.84 μg L-1 for chlorophytes, and 4.15-10.90/2.62-12.89 μg L-1 for cyanobacteria; depending on the biomass to chlorophyll-a conversion method. The RMSE were comparable to those from seasonal simulations, indicating that this model can be calibrated using a single parameter set for decade long simulations and that model drift was minimal. Finally, because 3D and 1D models require different computational power
iii
and have different agreement with observations, we cross-compared simulations from these two models against observations of water temperature, total phosphorus, phosphate, nitrate, total chlorophyll-a and cyanobacteria at three stations along a transect from near the Maumee River mouth to mid-basin (average RMSE of 1.18/3.28 ℃, 0.04/0.05 mg L-1, 0.01/0.05 mg L-1, 0.71/0.93 mg L-1, 21.99/19.50 μg L-1, and 5.76/14.74 μg L-1 for AEM3D-iWQ/AED-GLM, respectively). The results show that 1D AED-GLM performed better in capturing the cyanobacteria bloom years, as this horizontally-averaged model was automatically calibrated to basin-average values, while 3D AEM3D performed better in reproducing seasonal and spatial variations of nutrients and phytoplankton at discrete stations, especially the algal plume near the Maumee River mouth.

abstract: PhD


title: Towards Generating a Library of Metastatic Phenotypes from Structured Radiology Reports

contributor:
Simpson, Amber
Zulkernine, Farhana
Computing

subject:
metastases
machine learning
radiology
natural language processing (NLP)
cancer
convolutional neural networks (CNN)
consecutive reports
TF-IDF
computed tomography (CT)

abstract:
One in four Canadians will die from cancer. The majority of cancer patients die not from their primary tumor but from the progression of metastatic disease. Among patients with metastatic disease, the patterns of disease spread are increasingly recognized as an important stratification variable for treatment selection. While historically, disease patterns have been described in autopsy series, identifying these patterns in all patients undergoing treatment may improve our understanding of the natural history of different primary cancers and the organotropism of metastatic disease, thereby facilitating better clinical reasoning and decision-making. Radiographic imaging plays a central role in identifying metastatic disease.
This thesis tests the working hypothesis that a ten-year database of computed tomography (CT) radiologic reports contain sufficient information for machine learning (ML) to identify metastatic phenotypes based on disease progression patterns. Natural language processing (NLP) will allow the use of structured radiology reports as weak labels for semi-supervised classification of over 700,000 CT reports. This research is made possible by recent advances in the field and capitalizes on our unique access to large amounts of structured reporting data.

The thesis has two contributions: the first uses NLP models for single-report metastases detection, while the second uses deep learning models to detect metastatic disease across multiple consecutive reports. The single-report work aims to measure the frequency of metastatic disease in different organs reported on CT scans of the chest, abdomen, and pelvis over a ten-year period at a cancer center, using time frequency-inverse document frequency (TF-IDF) and ensemble machine-learning models to make predictions. It was demonstrated that NLP can achieve high accuracy (90\%-99\%) in extracting metastatic disease labels in different organs within structured radiology reports for cancer patients. The second contribution is to further improve the detection of metastatic disease over time from these same structured radiology reports by exposing prediction models to historical information. We use NLP to extract and encode important features from the structured text reports, which are then used to develop, train, and validate models. Three models – a simple convolutional neural network, a convolutional neural network augmented with an attention layer, and a recurrent neural network – were developed to classify the type of metastatic disease and validated against the ground truth labels. The models use features from consecutive structured text radiology reports of a patient to predict the presence of metastatic disease in the reports. This research demonstrated that neural network NLP prediction models can generate better weak labels for semi-supervised classification of CT reports when exposed to consecutive reports through a patient's treatment history.

Our results suggest that NLP models can extract cancer progression patterns from multiple consecutive radiology reports and predict the presence of metastatic disease in multiple organs with high performance. This is the first time that NLP has been applied to study metastatic progression. We demonstrate a promising automated approach to label large numbers of radiology reports without involving human experts in a time- and cost-effective manner and enables tracking of cancer progression over time.

abstract: M.Sc.


title: EXPERIMENTAL INVESTIGATION OF THE STRUCTURAL MECHANICS AND PERFORMANCE OF CLOSE-FIT FLEXIBLE LINERS INSTALLED IN CORRUGATED STEEL STRUCTURES

contributor:
Moore, Ian
Civil Engineering

subject:
Rehabilitation
Structural Mechanics
Limit States
Structural Performance
Soil Structures
Thin wall structures
Cured-in-place-pipe
Corrugated Steel
Close-fit-liners
Flexible Structures

abstract: This thesis investigates the structural behaviour of corrugated steel culverts lined with cured-in-place-pipe liners under vehicle and hydrostatic loads through the conduct of full scale experiments. Further, with the tested structures, section and material properties of the liners are characterized and the relevant quality assurance practices are reviewed. The goal is to elucidate the mechanics governing the load resistance and capacity of these systems for the future development of design equations. Digital image correlation, electrical resistance strain gauges, string potentiometers, and fibre optic strain sensors were employed to study the behaviour of structures rehabilitated with two different liner materials: 1) a polyester filled felt and 2) a glass reinforced epoxy. Further, with optical fibre strain sensors, a new monitoring technique was prototyped and implemented to measure the response of the liner. Next, a study was undertaken to quantify the section and material properties of the two different CIPP liner materials. The results from the vehicle load studies demonstrate inadequacies in the present design guidelines for these structures, likely dependent on the closeness of fit between the liner and host pipe. Testing these structures up to their ultimate strength limits revealed that the liner-host-pipe-soil system may fail from either the host pipe forming a plastic hinge, or buckling of the liner. It was found that the cured-in-place-pipe liners reduced the peak curvature change and neutral axis strains that develop in the corrugated steel pipe due to vehicle loading by at least 39% and 43% respectively. The results from the hydrostatic load test, where external water pressure was applied to the felt liner, demonstrated that the application of the latest analytical models which account for ovaling and gap (Thépot 2021) may provide conservative approximations for the critical buckling pressure, deflection, moment, and thrust of the liner. The results from the section properties study demonstrated that both materials were close to if not more than the design thickness as well as quantified the thickness distribution and variability of the two liner materials. Further, sample size charts, have been developed and can be used to determine the number of measurements required to verify that the liner’s thickness is within some acceptable range of the design thickness for different standard deviation values. Finally, from the review of relevant material test standards, implementation gaps in the North American guidance are highlighted.

abstract: PhD


title: CHEMICAL AND MINERALOGICAL CHARACTERIZATION OF AIRBORNE PARTICULATE MATTER ORIGINATING FROM MINING AND INDUSTRIAL OPERATIONS

contributor: Geological Sciences and Geological Engineering

subject:
Automated Mineralogy
Dust Monitoring
Nickel
Copper
Sequential Leaching

abstract:
Activities performed at mining and other industrial operations are capable of producing significant quantities of particulate matter that, if not properly contained, can be harmful to workers, and can enter surrounding communities causing damage to local environments. Analysis of particulate matter through routine monitoring is not always sufficient for characterizing substances of concern and differentiating between sources that contribute to emissions. To better understand the types of particulate matter generated at Ni and Cu mining and processing operations in Canada and Europe, a combination of quantitative mineralogy and methods of geochemistry (bulk chemistry, sequential leaching, trace-element geochemistry, and Pb isotope systematics) were performed. Particulate matter samples with varying size ranges (PM10, PM2.5, respirable, and inhalable) were collected within the workplace and at ambient air monitoring stations adjacent to the operations. The composition of the overall dust and the types of metal compounds present in the dust were determined with the objective of assessing worker exposure and investigating the extent to which emissions reach the adjacent communities. Baseline analysis of particulate matter generated during key activities at the operations, and analysis of source materials and settled dust provided additional information that was used for calculating source apportionment and investigating strategies for mitigating emissions.
The key findings of the study are that, due to the complexity of sources, workplace exposure at any operation investigation beyond government-mandated guidelines to identify relationships between documented health effects in workers and specific exposures. Routine methods of characterizing hazardous metals in dust, such as sequential leaching, should be calibrated for individual operations that deal with a unique set of substances, and should include more than one type of analysis. When activities are performed at operations, only minimal wind speeds are necessary to transport dust distances at least 2 km from an operation into the surrounding environment and community, and a complex variety of particulate matter is present in urban areas surrounding industrial operations and can have multiple sources that are not related to the operation itself. The apportionment data allowed personnel at the operations to determine the source of emissions relative to activity, and mitigation strategies were implanted to reduce emissions.

abstract: PhD


title: The Effect of Lead on Dealloying and Stress Corrosion Cracking (SCC) of Ni-Cr-Fe Alloys in Boiling Caustic Environments

contributor:
Persaud, Suraj
Mechanical and Materials Engineering

subject:
Material Science
Corrosion
Stress Corrosion Cracking (SCC)
Dealloying

abstract: 304L stainless steel (SS) samples were exposed to a highly caustic 50 wt.% NaOH environment at or near the boiling temperature (135-140 °C) in reducing conditions to study dealloying. Flat samples were used for electrochemical measurements, and SS 316L was used in some tests to evaluate the effect of Mo addition and subtle changes in Ni content. Twisted and U-bend samples of SS 304L were used to evaluate the effect of stress on dealloying and SCC. All exposed surfaces were characterized post-exposure using optical microscopy, scanning electron microscopy (SEM), and energy dispersive x-ray spectroscopy (EDS) chemical analysis with additional characterization done on some samples at the nanoscale using transmission electron microscopy (TEM). Following testing in pure caustic, SCC tests and electrochemical measurements were then repeated in lead-contaminated (5, 50, and 500 ppm), caustic environments with lead added as PbO. The effect of dissolved Pb concentration and its possible effect on dealloying susceptibility was evaluated. The effect of Pb addition on SS 304L was found to shift the open circuit potential towards a more positive value. It was also noted that the addition of Pb had a delaying effect on dealloying that consequently slowed SCC in comparison to the results obtained in pure caustic conditions. This effect was attributed to the deposition of metallic Pb on the Ni-rich surface formed after dealloying of a few atomic layers. Pb deposition blocked dissolution pathways which slowed dealloying kinetics and subsequently hindered SCC initiation in comparison to pure caustic conditions.

abstract: M.Sc.


title: Leveraging Multi-Source Remote Sensing Images and Deep Learning to Map Caribou Lichens

contributor:
Chen, Dongmei
Geography and Planning

subject:
remote sensing
deep learning
lichen mapping

abstract: Given the importance of lichens for caribou during winters, disturbances to caribou lichens may affect caribou migration and distribution patterns, and possibly lead to their population declines. Using remote sensing (RS) data, it is possible to monitor forage lichen cover efficiently over large and inaccessible areas. In this thesis, three significantly challenging problems in lichen cover mapping (especially Cladonia spp.) in different regions of Canada (Newfoundland and Labrador, Quebec, and Northwest Territory) are addressed: 1) lichen mapping using limited ground-validation data; 2) deploying a single, universal model for lichen mapping in non-atmospherically corrected RS images; and 3) lichen fractional cover mapping over rocky landscapes where non-lichen features are spectrally similar to caribou lichens. To address these three challenges, we used a wide variety of RS images (micro-plot images, high-resolution aerial optical images, high-resolution satellite (HRS) images (WorldView-2 and -3), and airborne hyperspectral imagery (AVIRIS-NG)), and different advanced deep learning (DL) models. In the first phase of this research, we found that semi-supervised DL for lichen mapping can improve lichen mapping compared to fully supervised learning in the presence of limited training data. In the second phase, our experiments showed the high potential of Generative Adversarial Networks (GANs) for normalizing non-atmospherically corrected HRS images for lichen mapping using a single, universal lichen detector model under different atmospheric conditions. In the last phase of this research, we found that using AVIRIS-NG hyperspectral imagery, lichen fractional cover mapping was more accurate than using HRS imagery over a rocky landscape where non-lichen bright features resembled lichen species of interest (Cladonia spp.). The studies conducted in this thesis are significant as they open new insights into how the use of state-of-the-art DL solutions and multiple sources of RS data can improve the quality of lichen mapping under different challenging circumstances. One of the most important contributions of this study is that all the methods and results presented in this thesis can also be readily applied to other vegetation mapping applications using RS data as the methods were designed in such a way that they do not depend on a specific land cover type or application.

abstract: PhD


title: Implanting of an Ideology: Television, Politics, and the Making of the Hindu Right in Contemporary India

contributor:
Bakan, Abigail
Political Studies

subject:
Hindu Right
Tradition and Modernity
Indian Politics
Ramayan
Television serial

abstract:
Similar to developments in many parts of the world, in India, right-wing Hindu nationalists have appeared as a powerful group, shaping the ideological discourse and successfully capturing state power under Prime Minister Narendra Modi’s leadership. This dissertation delineates the emergence of the Hindu Right in contemporary India in conversation with the Hindu epic Ramayan. The study’s central focus is the television adaptation of the Ramayan (TVR) that was broadcast on the state-run national television network in 1987 and 1988. This is seen as a marker event following which there was a right-wing drift towards the ideology of the Hindu Right. I argue that the TVR was a formidable instrument in making the ideology of the Hindu Right palatable among a large segment of the Indian population. Following a close textual reading of the epic, this study demonstrates how the televised Ramayan reorganised and repackaged the epic in such a way that it became foundational in redefining the contours of the Indian nation along the lines of Hindu nationalism.

To explain the appeal of Ramayan, I undertake a historical investigation to show that at previous moments of crisis in the Indian caste/class society, the epic was deployed by the ruling classes to regain their slipping hegemonic control. I argue that the TVR is a modern-day rearticulation of the same phenomenon, where claims to tradition are maneuvered to project forward to a future utopian society: a utopian society that contains a critique of the existing order, as well as an appeal to rebuild using wisdom contained within Indian (read upper-caste Brahmanical) tradition.

This project makes a wide theoretical intervention by contending that the fundamental flaw in our understanding of the growth of the Hindu Right lies in how scholarship has conceptualised the relationship between tradition and modernity. I suggest that instead of considering departing from tradition as a radical rupture, understanding modernity as an ongoing modernisation of tradition provides a more nuanced insight into the phenomena.

abstract: PhD


title: Small Talk: A Big Challenge for Chinese Graduate Students in Canada

contributor:
Myers, Marie
Education

subject:
Small talk
Chinese graduate students
Social integration
Communicative competence

abstract:
This phenomenological inquiry explores the lived experiences of Chinese graduate students in Canada when making small talk with native English speakers. The focus is on the challenges they face, possible causes for these challenges, and potential solutions. The theoretical frameworks consist of a combination of the communicative competence model and the concepts of languaculture and communities of practice.
Ten Chinese students in Canadian universities were interviewed to collect data on their experiences making small talk with instructors, classmates, and other members of their local communities and on their progress with social interaction and integration.
In addition, eight Canadian instructors and classmates were invited to participate by completing an online questionnaire which asked them to outline their experiences with Chinese students. They were also presented with sample narratives from the interviewees revealing difficult personal interactions and asked to provide commentary and suggest strategies they would use under similar circumstances.
Thematic data analysis was used to codify and categorize the information collected. The results indicated the most challenging issues for these Chinese students were related to comprehension, participation, initiative, confidence, social connections, and propriety. There were many direct or indirect causes for these challenges, but most were the result of problems tied to language proficiency, cultural differences, and personal attributes. Suggested solutions include practicing communicative skills, improving English language proficiency, learning social and cultural norms, developing communicative strategies, and becoming active members in communities of practice.
It is hoped that the results will provide useful information for Chinese and other international students to better prepare them for academic life in Canada. Policy makers, instructors, and other native speakers can also benefit by gaining an understanding of one of the significant social barriers faced by international scholars and other immigrants.

abstract: M.Ed.


title: Scheduling Problems in Next Generation Computing Networks

contributor:
Choudhury, Salimur
Salomaa, Kai
Computing

subject:
Scheduling
Multi-access edge computing
Fog computing
Resource allocation
Task assignment

abstract:
With the development of the novel Internet of Things (IoT) ecosystem, the digital support required by emerging applications is a highly growing area of concern. The current network paradigm, cloud computing, is proving unable to adequately support the ever increasing computational and storage needs of the billions of edge devices in use. In recent years, several solutions have been put forward including two complementary computing paradigms: Multi-access Edge Computing (MEC) and fog computing. MEC and fog computing are both considered augments to cloud computing since they both conceptualize supplementary server layers to existing networks.

This thesis addresses the emerging challenge of efficient task scheduling in both MEC and fog computing. Since traditional mathematical programming models are proven to be very difficult to solve optimally at large dimensions, another approach is needed to satisfy the time-sensitive needs of the dynamic environments of both MEC and fog computing. In this thesis, we propose several heuristics that are designed to provide good solutions while maintaining low complexity guarantees.

The first problem examined in this thesis is how to fully utilize parked vehicles (PVs) as computational resources in vehicular networks under the MEC framework. We formulate a multi-objective task offloading problem that minimizes both task delay and wireless channel load. Then, a stable matching based heuristic is proposed and evaluated at various configurations of the vehicular environment.

The second problem that we examine in thesis is how to fairly allocate resources in fog computing. Fairness in resource allocation is a highly desired quality because it not only increases the quality of service (QoS) for users but also maximizes the resource utilization in the system. This thesis adopts the Dominant Resource Fairness (DRF) scheme and applies it to a multi-resource, multi-server, and heterogeneous task environment. Furthermore, four different types of tasks are considered: ordered/unordered, splittable/unsplittable. Finally, three different low complexity heuristics are proposed to maximize fairness between users under the DRF scheme.

abstract: M.Sc.


title: Investigating the Role of Trained Immunity in Bacillus Calmette-Guérin Immunotherapy of Bladder Cancer Using a Mouse Model

contributor:
Graham, Charles
Biomedical and Molecular Sciences

subject: Bladder Cancer

subject: Bacillus Calmette Guérin (BCG)

subject: Non-muscle invasive bladder cancer (NMIBC)

subject: Tumour resection of bladder tumour (TURBT)

subject: Trained immunity

subject: Antitumour

subject: Proinflammatory cytokines

subject: Anti-inflammatory cytokines

subject: Epigenetic reprogramming

subject: Optimization

subject: Intravenous (IV)

subject: Intraperitoneal (IP)

subject: Intravesical

subject: Pre-clinical

subject: Mouse model

subject: Immunotherapy

subject: Systemic

subject: Local

abstract: The gold-standard treatment for non-muscle invasive bladder cancer (NMIBC) is adjuvant intravesical Bacillus Calmette-Guérin (BCG) immunotherapy following transurethral resection of bladder tumour (TURBT). BCG is a live-attenuated form of Mycobacterium bovis and is utilized in an adjuvant setting to potentiate antitumour immunity. However, the mechanism of action by which BCG induces its therapeutic benefits is not fully elucidated. Recent studies suggest that trained immunity (TI) may be a key mediator of BCG immunotherapy. TI is characterized by an enhanced response to a secondary, inflammatory stimulus, mediated by the innate immune system. A study from our laboratory has shown that monocytes from patients that have undergone BCG immunotherapy can acquire TI, which has shown to be associated with long-term recurrence-free survival. Therefore, we hypothesized that the antitumour effects of BCG therapy are mediated by acquisition of TI. Furthermore, we proposed that systemic modes of training, i.e. intraperitoneal (IP) and intravenous (IV), result in greater levels of TI compared to local intravesical inoculation. The objectives of this study were to establish an orthotopic, syngeneic MB49 mouse model of bladder cancer and BCG immunotherapy, followed by a comparison of the levels of TI acquired by bone marrow derived monocytes of non-tumour-bearing mice inoculated with BCG through the routes of IP, IV or intravesical. Here, we found that intravesical BCG immunotherapy did not elicit a prolonged antitumour effect nor it induced TI in bone marrow monocytes. Similarly, BCG administered IP, IV, or intravesically to non-tumour bearing mice did not result in TI acquisition. However, intravesical administration of BCG, compared to IP and IV administrations, induced BMDMs to secrete heightened levels of proinflammatory cytokines and chemokines (IL-1β, IL-6, and MCP-1) in response to LPS challenge. These results provide some evidence that systemic versus local administration of BCG leads to differential immune responses. Overall, the findings could lead to better approaches to optimize BCG immunotherapy of bladder cancer.

abstract: M.Sc.


title: Developing a Technique to Create a Uniform, Targeted, Transient Shear Stress Stimulus to Assess Endothelial Function

contributor:
Pyke, Kyra
Kinesiology and Health Studies

subject:
Endothelial function
Flow-mediated dilation
Shear stress
Shear rate
Stimulus control

abstract: The lining (endothelium) of blood vessels regulates vessel health and diameter. Blood flow-associated shear stress (frictional force) imparted on the endothelium stimulates vasodilation (flow-mediated dilation, FMD). FMD as an index of endothelial function is stimulated by an uncontrolled increase in shear stress created with limb occlusion release [reactive hyperemia (RH)-FMD]. RH-FMD interpretation is complicated because differences in RH-FMD between groups/conditions may reflect stimulus magnitude variability rather than distinct endothelial function. Moreover, smaller diameter arteries tend to have larger FMD responses and it is unclear whether this can be attributed to a larger stimulus or other factors related to artery size. The purpose of this thesis was to develop a controlled, targeted, transient RH (CTRH) shear stress stimulus and to compare CTRH-FMD to standard RH-FMD. We hypothesized that the CTRH test would reduce stimulus and FMD response variability and eliminate any relationships between artery size, shear stress, and FMD. Twenty-one healthy adults (ages 22 ± 3) participated in two visits each involving three trials of the RH or CTRH test. The CTRH test incorporated three minutes of handgrip exercise during the occlusion to create a large RH “reserve”. During 40s of cuff release, RH in the brachial artery of the arm was controlled at a target shear stress of 120s-1 by pressing on the vessel at the inside of the elbow. The CTRH test reduced stimulus variability compared to the RH test [within-subject coefficient of variation (CV) CTRH: 3.4 ± 2.3% vs. RH: 8.9 ± 4.6%; p < 0.001] , while FMD response variability remained unchanged (within-subject CV CTRH: 28.9 ± 17.9% vs. RH: 26.8 ± 26.6%; p = 0.350). Although smaller arteries experienced a larger stimulus in the RH test (r2 = 0.27; p = 0.0181), there was an unexpected positive relationship between artery size and FMD (r2 = 0.22; p = 0.0451). The artery size-FMD relationship in the CTRH test was eliminated, however, the importance of stimulus control to this elimination is unclear. We demonstrated that a transient shear stress stimulus can be controlled and targeted. Future research is needed to assess the utility of CTRH-FMD for investigations of vascular function and health in a wider population.

abstract: M.Sc.