title: A Phenomenological Model for the Planimetric Evolution of Meandering Rivers and Related Database

contributor:
da Silva, Ana Maria Ferreira
Civil Engineering

subject:
Meandering Rivers
Planimetric Evolution
Meandering River Database

abstract: This work concerns the planimetric evolution of free meandering rivers, whose associated riverbank erosion and channel changes notoriously pose a hazard to infrastructure within their vicinity as well as affect the health of the river ecosystem. It aims to address two research needs, those being (1) the lack of easy access to an ample number of experimental (i.e. laboratory and/or field) cases for which the hydraulic and geomorphic characteristics of the streams are detailed together with an account of their channel displacements over time, and (2) the shortage of zero-th order approximation models available to simulate and predict channel planimetric evolution. Based on the results of a rigorous literature review and survey of historical imagery archives, the former is addressed through the compilation of a database which couples the planimetric evolution of a river meander loop with its stream characteristics. The specific methodology used to extract the planimetric geometry from imagery is detailed, and if not specified in literature, the stream hydraulic characteristics are estimated using well established methods. The resulting graphical database includes information on 29 sites from 25 different sand and gravel rivers. The need for zero-th order models is addressed by focusing on eliminating the present limitations of the phenomenological planimetric evolution model by da Silva and Yalin (2017). A MATLAB computer program is introduced, which for the first time enables the automated application of the just mentioned model. A yet unknown multiplier-function embedded in the model is revealed on the basis of the computer program and field cases from the present database. The multiplier function was found to be a function of the width-to-depth ratio, in addition to stream sinuosity. The present applications of the model show that it can predict the spatial growth of meander bends of relatively symmetrical channels over several years not exceeding the development of a channel cut-off.

abstract: M.A.Sc.


title: Hippocampal Contributions to Gist and Detail Constructs of Episodic Memory

contributor:
Poppenk, Jordan
Psychology

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

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

rights: Intellectual Property Guidelines at Queen's University

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

subject:
Memory
Hippocampus
Long-Axis Specialization
Gist
Detail

abstract: Cognitive theories like Fuzzy Trace Theory or Multiple Memory Trace Theory have implied a distinction between coarse- and fine-grained processing of details for constructs of episodic memory. These distinctions in memory constructs possess similar attributes when compared to specialized functional processing of the anterior and posterior hippocampus segments, being pattern completion and pattern separation. This study attempted to combine both behavioural and imaging theories to uncover the neural mechanism responsible for the distinction in memory type. Participants viewed a 20-minute short film, interleaved with 5-minute rest segments, and later gave a free recall of the film. Free-recall audio files were transcribed and analysed for content, assessing the composition of gist and detail statements. These transcript scores were regressed onto hippocampal segment volume to reveal the predictive value of hippocampal segment volume on memory type. The results of this study showed larger left anterior and smaller right posterior hippocampal volume predicted more detail statements in a free recall transcript. Additionally, this study attempted to show the mechanism by which gist memory representations were consolidated. Using Representational Similarity Analysis, encoding and rest fMRI data were analyzed to observe whether the re-emergence of encoding patters could predict successful recall. While the data did not support this theory, results from this study provided valuable methodological insights for future data collection involving complex naturalistic stimuli.

abstract: M.Sc.


title: System Design and Performance Study for Wireless Information and Energy Transfer in the Internet of Things

contributor:
Yousefi, Shahram
Electrical and Computer Engineering

subject:
Internet of Things
Energy Harvesting
Wireless Communications
Signal Processing
Multiuser Systems
Cellular Networks

abstract:
In a tremendous evolution, billions of physical objects are being connected to the Internet, shaping Internet of Things (IoT) as one of the most disruptive technologies that has ever been witnessed. This revolutionary technology, however,  encounters the key challenge of sustainability. Wireless information and energy transfer (WIET) has emerged as a promising solution to overcome this significant challenge.
This thesis focuses on developing WIET with respect to the realistic applications and enhancing the system performance through devising effective signal processing methods and novel system designs.
We study point-to-point WIET systems with bidirectional communication. Multiple-input multiple-output (MIMO) with antenna switching (AS) and beamforming are investigated to improve the achieved downlink-uplink rate region in such systems. An optimal and a low-complexity algorithm are proposed to solve the problem of joint optimization of AS and beamforming. It is shown that the computational complexity can be substantially alleviated and also a near-optimal performance can be obtained by the proposed low-complexity algorithm.
Moreover, we investigate the orthogonal and non-orthogonal multiple access (OMA and NOMA) in the downlink WIET systems. The analytical results show that OMA can achieve a larger rate region than NOMA when the channel power gains of users are not sufficiently different. Also, we show that cognitive-radio-inspired NOMA (CR-NOMA) as an important variation of NOMA can outperform OMA only if the channel power gains of users are sufficiently different and the target rate of the weak user is above a threshold.
Finally, we propose novel coordinated multi-point NOMA (CoMP-NOMA) schemes, namely joint transmission NOMA (JT-NOMA) and Alamouti NOMA (A-NOMA), to combat the key challenge of inter-cell interference (ICI) in the multicell WIET networks. We show that A-NOMA can achieve a larger outage rate region than JT-NOMA and joint transmission OMA (JT-OMA) in high signal-to-noise ratio. A particularly interesting observation is that when the difference between the expectations of effective channel power gains is not sufficiently large, JT-OMA performs better than JT-NOMA.
This dissertation contributes to transforming WIET form a potential solution into an enabling technology which can significantly improve the spectral efficiency and sustainability in wireless networks and IoT systems.

abstract: PhD


title: Bioinformatics Approaches for Investigating Missing Heritability in Complex Traits

contributor:
Duan, Qingling
Biomedical and Molecular Sciences

rights: Attribution-NonCommercial-NoDerivs 3.0 United States

subject:
Bioinformatics
Genomics
Genetics
Omics
Computational Biology
Missing Heritability
Machine Learning
Omics Integration
Gene-Environment Interaction
Gene-Gene Interaction
Network Analysis
Variant Annotation
Linkage Disequilibrium
Asthma
Recurrent Wheeze
Ovarian Cancer
Chemoresistance
Pharmacogenomics
Computational Genomics
Complex Trait

abstract: Advancements in high-throughput technologies and high-performance computing have enabled the discovery of tens of thousands of genetic associations for complex traits and diseases. However, these associations explain only part of the heritability, defined as the portion of the trait variability that is accounted for by genetic factors. The overarching goal of my dissertation is to investigate the missing heritability in order to improve our understanding of the underlying genomic factors. First, we tested the hypothesis that many of the associated markers for complex traits are non-causal but are in linkage disequilibrium (LD) with causal variants. We identified 27 potentially functional variants in LD with previously associated markers for drug response outcomes, which could account in part for the missing heritability of pharmacogenomic traits. Next, we examined the main effects of genetic variations as well as interaction effects with environmental exposures in determining risk of complex diseases. In our study of childhood asthma, we computed the genetic risk score (GRS) by integrating the weighed effects of multiple genetic variants and determined that early-life modifiable exposures interact with genetic risk to determine respiratory outcomes. Finally, we applied a weighted network model and machine learning algorithm to investigate biological networks associated with chemotherapy response among ovarian cancer patients and identified potentially regulatory variants (expression quantitative loci: eQTL) associated with gene expression. In summary, my thesis work demonstrates that the missing heritability of complex traits may be explained in part by accounting for polygenic effects, gene-gene interactions, gene-environment interactions, linkage disequilibrium, and integrative analysis of 'omics datasets.

abstract: PhD


title: The Island on the Hill: A Kingdonian Analysis of Congressional Decision-Making on the Puerto Rican Question

contributor:
Conaghan, Catherine
Political Studies

subject:
Congressional Decision-Making
Puerto Rican Status Question
United States-Puerto Rico Relations
Multiple Streams Approach (MSA)

abstract:
The two-fold purpose of the thesis is to: (1) advance a theoretical contribution to the study of congressional agenda-setting, and (2) add to the literature on Puerto Rican status politics. In the field of public policy, John Kingdon’s model has provided a durable explanation of how agendas and policy alternatives are developed in the United States and other democratic systems. A new generation of social scientists has added value to his work in what has been termed the Multiple Streams Approach (MSA). The application of Kingdon’s model to the Puerto Rican status issue between 1989 and 2017 reveals that while the model does much to explain why the issue falls of the congressional agenda, there is significant room to improve the model.
Greater emphasis on variables such as House-Senate differences in the U.S. Congress, the history of the policy of commonwealth, and agenda denial improved the analytical power of the model.  The unique constitutional framework of unincorporated territory since its acquisition by the United States from Spain in 1898 remains key to understanding Puerto Rico’s relationship with the federal government.  The dissertation is a longitudinal single-unit case study focusing on two points: when the Puerto Rican status legislation was passed by the House, and then fell off the decision agenda in the Senate in 1998 and 2010.
Senate bill 472 (S. 472) and House of Representatives bill 2499 (H.R. 2499) were shelved by the Senate in 1998 and 2010, respectively. In both cases, the reasons for this had to do with lack of Puerto Rican representation in the Senate and the Senate’s blocking Puerto Rican statehood in a display of agenda denial. Conservative Republican Senators would not support statehood.
In these cases of the Senate’s rejection of companion legislation, the antiquated nature of the commonwealth, created by the Popular Democratic Party (PPD) and Congress in 1952, accounted in part for why the Puerto Rican status issue fell off the agenda. Congress did not accept the PPD’s definition of commonwealth as more than a territory.

abstract: PhD


title: Reliability of Vasodilation in Response to Passive Leg Movement in Young, Healthy Women

contributor:
Pyke, Kyra
Kinesiology and Health Studies

subject:
Reliability
Endothelial Function
Passive Leg Movement
Lower-Limb Microvascular Function

abstract: Passive leg movement (PLM) elicits rapid vasodilation and an increase in blood flow, that is dependent on the function of the endothelial cells that line the small arteries in the leg.  The increased flow therefore provides an index of endothelial function in the lower-limb microvasculature. This index has identified alterations in endothelial function in advanced aging and clinical populations, demonstrating that the vasodilatory response to PLM provides a useful assessment of vascular responses. Understanding the day-to-day variation in arterial responses is important when distinguishing meaningful changes in endothelial function, however, there is currently limited information regarding the reliability of PLM-induced vasodilation. It was expected that performing three trials of PLM on two separate days would allow for a robust quantification of day-to-day reliability. Seventeen, young healthy women (22 +/- 3 years) participated in two identical experimental visits during the low-estrogen menstrual phase. Endothelial function was assessed each visit by conducting three trials of PLM. The reliability of PLM-induced vasodilation was quantified by calculating the Pearson correlation coefficient (r value), intraclass correlation coefficient (ICC) and coefficient of variation (CV). Additionally, typical error (TE) was calculated for future identification of individual differences in response to an intervention. The results demonstrated good reliability of the vasodilatory response to PLM characterized as peak leg blood flow (LBF; r = 0.84, ICC = 0.84, CV = 13.2%) and leg vascular conductance (LVC; r = 0.82, ICC = 0.79, CV = 14.4%), and change from baseline to peak LBF (r = 0.83, ICC = 0.82, CV = 17.8%) and LVC (r = 0.83, ICC = 0.80, CV = 16.5%). Characterization of PLM as change in area under the curve (AUC) was less reliable than the other PLM measures;  AUC LBF (r = 0.71, ICC = 0.70, CV = 31.2%) and AUC LVC (r = 0.78, ICC = 0.74, CV = 27.1%). This is the first full study to evaluate the reliability of PLM-induced vasodilation, demonstrating that it provides a reliable assessment of lower-limb microvascular endothelial function. These findings will support future studies aiming to classify meaningful individual vascular responses in women.

abstract: M.Sc.


title: Hybrid Distributed Stochastic Gradient Descent for Federated Learning

contributor:
Kim, Il-Min
Electrical and Computer Engineering

subject: Federated Learning

abstract:
With the advancement of information technology in the past decades, the world embraces the era of 'Big Data', in which large volumes of data are being produced in high velocity, while there is an increasing demand in processing these data. Such environment sets up a perfect playground for deep learning, which is able to utilize the large volumes of data to achieve various tasks. However, as both the volumes of data and the complexity of neural network architecture rises, it becomes increasingly expensive to train the model on a single machine. Federated learning becomes a hot research topic in recent years, which decentralizes the conventional deep learning architecture by distributing both data storage and/or computation operations to multiple machines, while it requires no exchange of information about the local training data so that the data privacy is preserved. In the literature, two different transmission approaches for federated learning, analog-based transmissions and digital-based transmissions, were studied and it was shown that the analog-based approach considerably outperforms the digital-based approach by utilizing the waveform superposition principle of the wireless access medium.

In this thesis, we propose the Hybrid Distributed Stochastic Gradient Descent (Hybrid DSGD), a training scheme for federated learning which utilizes the advantages of both digital and analog transmissions to reduce communication overhead and latency. We demonstrate why the conventional analog-based transmission schemes perform poorly when the number of workers participating the training and/or the power available for each worker are restricted. We then explain how our scheme addresses such issue. We will show through experiments that the hybrid DSGD is able to outperform the conventional analog-based transmission scheme under such circumstance.

abstract: M.A.Sc.


title: Neural Transition Metric in fMRI: Categorization and Application

subject:
fMRI
Brain Network Dynamics
Novelty
Hippocampus

abstract: Recent advances in technology allow us to examine brain network dynamics in fMRI on a large-scale. Our lab has recently developed a data-driven method, the neural transition metric (Tseng & Poppenk, 2020), which allows us to identify transitions in individuals’ mental states. My project employed the neural transition metric to 1. investigate the distinction between the externally and internally driven transitions (i.e., transitions induced by task stimuli vs resulted from internal mind-wandering), and 2. examine cognitive dynamics between the novel and repeated viewings of naturalistic movie stimuli. I found that there was no difference in brain correlates for the internally and externally driven transitions, whereas the event related transitions were associated with distinct profile of brain activations compared to the others. Moreover, through comparing the properties of neural transitions between the novel and repeated viewing, I found that movie stimuli are less effective at aligning viewers’ cognition in repeated viewing. This suggests that with repeated viewing, participants’ thoughts became more idiosyncratic and more internally driven. Additionally, degree of conformities (i.e., the alignment of transitions timing between the individual and the group) in the novel and repeated viewings were correlated with volumes of the anterior/posterior hippocampus (a/pHPC) and amygdala, such that individuals with bigger aHPC and amygdala displayed higher conformity in the novel run, whereas individuals with bigger pHPC have lower conformity in the repeated run. This collectively demonstrated that our neural transition metric could have a broader application in experiments involving naturalistic stimuli by offering unique insights into our cognitive dynamics.

abstract: M.Sc.


title: Do Physical Activity and Sedentary Behaviours During Adolescence Predict the Development of Type 2 Diabetes During Early Adulthood?

contributor:
Janssen, Ian
Kinesiology and Health Studies

subject:
Physical Activity
Sedentary Behaviour
Epidemiology
Type 2 Diabetes
Adolescence

abstract: Background: Little is known about whether adolescent physical activity and sedentary behaviour levels predict health in adulthood. The first objective of this thesis was to determine whether participation in moderate-to-vigorous physical activity in adolescence is associated with type 2 diabetes risk in adulthood. The second objective was to determine whether time spent in different types of sedentary behaviour (e.g., TV watching, reading) are associated with type 2 diabetes risk in adulthood. Methods: Data for the physical activity and sedentary behaviour analyses were based on 4845 and 3942 adolescents, respectively, who were aged 16 years at baseline. Physical activity was measured at baseline using a self-reported activity checklist where participants indicated what activities they participated in and how often they participated in them. Sedentary behaviour was assessed at baseline using a questionnaire where participants reported how much time they watched TV and videos, used the computer, read and did homework. Participants were followed for 30 years (from age 16 to age 46). Cases of type 2 diabetes were determined every 4 years in the follow-up period in a self-reported manner. Results: By comparison to those in the lowest physical activity quartile, those in quartile 2 had a 43% decreased risk of type 2 diabetes. However, type 2 diabetes risk was not significantly reduced in physical activity quartiles 3 and 4. By comparison to those who watched ≤120 minutes/day of TV and videos, those who watched >240 minutes/day had a 106% increased risk of type 2 diabetes. Time spent using the computer, reading and doing homework were not associated with type 2 diabetes risk. Conclusion: It appears that watching TV and videos, but not physical activity levels or other sedentary behaviours, is associated with type 2 diabetes risk.

abstract: M.Sc.


title: Animal Ascension: Elevation and Debasement Through Human-Animal Associations in English Satire, 1700-1820

contributor:
Errington, Elizabeth Jane
History

subject:
Animal History
Eighteenth Century
Satire
Scriblerian
Caricature
Animal
Alexander Pope
Jonathan Swift

abstract: Animals were integral to conceptions of human identity and society in the long eighteenth century. English satirists employed human-animal associations in their undermining and subversion of authority, and wielded animal symbolism as a tool for both praise and vilification. Progressively, these associations formed processes of human debasement and animal elevation that blurred the traditional distinctions between species, and allowed for Animal Ascension. This study of animals in eighteenth-century satire draws upon both literary and visual sources to investigate how these satirists engaged with a rich foundational ‘Animal Vocabulary,’ contemporary theories and debates surrounding animal faculties and human exceptionalism, and their own personal relationship with other species. The first chapter shall introduce the Scriblerians, their peers, and the nature of satire as it was understood in England at this time. The second chapter will expand upon the traditions and genres that predated the works studied, and how these influenced the Scriblerians. The third chapter investigates human debasement through individual attacks, social regulation and geopolitics. The fourth chapter turns to animal elevation as a powerful didactic tool supported by a developing admiration for animalkind. The fifth chapter considers how the distinctions between humans and animals were the subject of vigorous debates, and explores how animal elevation was compounded by satirical inversion. Finally, the chapter also discusses theories of decivilization and presents a short case study of the North American colonies held by Britain during the eighteenth century, in order to demonstrate that European colonial fears were often hinged upon animal practice and observation.

abstract: M.A.


title: Investigating the Blockade of Transforming Growth Factor-beta Signaling in Preclinical Models of Epithelial Ovarian Cancer

contributor:
Craig, Andrew
Biomedical and Molecular Sciences

subject:
Ovarian Cancer
Transforming Growth Factor-beta
Ovarian Tumour Microenvironment

abstract: Ovarian cancer is the most the lethal gynecologic malignancy and most commonly develops as epithelial ovarian cancer (EOC). Most EOC tumours are genetically unstable high-grade serous carcinomas that initiate and grow rapidly leading patients to present with late stage metastatic disease. Patients undergo debulking surgery followed by rounds of platinum-based chemotherapy and, although initial response rates are favorable, over 70% of patients experience recurrence of treatment-resistant tumours resulting in dismal 5-year survival rates (~30%). The need to develop therapeutic strategies for metastatic EOC has spurred investigation into signaling networks in the tumour microenvironment that support malignant progression. Transforming growth factor-β (TGF-β) is a pleiotropic growth factor that contextually impacts cell behaviour and is frequently employed by advanced tumours to exacerbate growth and metastasis. Current inhibitors of this pathway are limited by poor specificity, toxicity, or insufficient efficacy as single agents. In EOC, TGF-β signaling networks induce epithelial-mesenchymal transition (EMT)-mediated metastasis and promote resistance to platinum chemotherapy. In this thesis, novel synthetic antibody fragments targeting TGF-β receptor II (TGFBR2) were characterized in EOC cell lines and in mouse models as single agents and in combination with carboplatin. Targeting TGFBR2 successfully improved sensitivity to chemotherapy by limiting EMT and immune exclusion, leading to infiltration of cytotoxic immune cells and fewer suppressive cells in EOC tumours. M7824, the bifunctional inhibitor of PD-L1 and TGF-β, was also deployed in a syngeneic EOC mouse model. M7824 treatment hindered EOC metastasis and impaired immune exclusion by eliciting anti-tumour responses in macrophages and T cells. Prolonged treatment with M7824 elevated T cell exhaustion and costimulatory signatures characteristic of T cell dysfunction following persistent stimulation. Taken together, this thesis highlights the potential therapeutic benefits of TGF-β signaling blockade in EOC and provides rationale for investigating new combination therapies that impair EOC metastasis and improve survival.

abstract: PhD


title: The Knowledge Instruments in Smart City Legitimation and Critique: A Pragmatic-Sociology Assessment of the Case of Sidewalk Toronto

contributor:
Murakami Wood, David
Sociology

subject:
Smart City
Smart Urbanism
Speculative Urbanism
Infrastructure
Sidewalk Labs
Toronto
Legitimation
Justification
Public Relations
Public Sphere
Public-Private Partnership
Public-Private Governance
Intellectual Culture
Sociology
Pragmatism
Software
Surveillance
Interface
Ideology
Governmentality

abstract:
In recent decades, the smart city concept has gained momentum in policy and popular discourses. Largely a long-term marketing effort grounded in private technology firms such as IBM and Cisco (Söderström 2014, Hollands 2015), the meanings of and the actual/potential material assemblages involved in the idea have received sustained academic criticism. At once under the purview of urban studies, software studies, STS, law, and marketing, the smart city idea as it was written seems to be as plastic as it is multi-faceted.

This thesis explores the ways in which the idea of the smart city has been conceived through a literature review, and a case study of Sidewalk Toronto, a project conceived in October 2017 and terminated in May 2020. The review explores the conception of the smart city as, for example, algorithmic governmentality (Leszczynski 2016), as a threat narrative (White 2016), and as cybernetic urbanism (Krivy 2018). It identifies three leitmotifs of the idea as a conceptual movement: the presumption of the existence of ‘raw data,’ a dataism-driven urban teleology, and a theory-practice of post-politics governance.

This study adapts Luc Boltanski’s pragmatic sociology as framework and provides an identification of the smart city knowledge constructs, including ‘city-as-platform,’ ‘urban data,’ and ‘civil data trust’ that defined the controversy around Sidewalk Labs. These constructs were used to justify the project in Sidewalk Lab’s marketing and appeasement efforts; and to produce modes of criticisms counterposed by civil society actors, between 2017 and 2020.

abstract: M.A.


title: Fire Performance of FRP: Bond of GFRP Bars to Concrete and FRP Strengthened Columns

contributor:
Green, Mark F.
Hajiloo, Hamzeh
Civil Engineering

subject: Modified Pullout Test

subject: Fire Analysis

subject: Fibre Reinforced Polymer

subject: Finite Element Modeling

subject: FRP Bond Performance at High Tempetature

subject: FRP Wrapped Strengthening

abstract: Standard pullout tests (e.g. 200 mm cubes) with a short embedment length have shown a significant reduction (80% loss at 200 °C) in the bond strength of GFRP bars at high temperatures. More detailed bond behaviour of glass fibre reinforced polymer (GFRP) reinforcing bars has been examined in this study. This study adopted a modified pullout test method in which pullout specimens consisting of GFRP bars embedded in 350 mm (22db) long concrete cylinders are tested at high temperatures. The tests examined the bond degradation under different temperature distributions (i.e. uniform and gradient). The results were compared with the previous pullout tests with 68 mm (4db) embedment length and showed that the pullout capacity of GFRP bars in this test were 3.3, 4, and 2 times higher at 115, 135 and 300 °C, respectively. The results proved the effectiveness of longer embedment length particularly at temperatures below 200 °C. Pullout tests with temperature gradients simulated the bond behaviour of GFRP bars at the unexposed end zones of GFRP reinforced concrete beams or slabs. The results showed that the tensile force in GFRP bars gradually transferred to the lower temperature zones as the heated parts of the bar lost bond with concrete. The results showed that the concentrated forces over a short length of GFRP can trigger concrete splitting and loss of bond even if the GFRP bars still maintain bond with concrete. Providing thicker concrete cover at the end zones of GFRP reinforced members is recommended to enhance fire resistance. Also, a series of approximate and simple numerical models including heat and structural analysis were developed to study the effects of high temperatures on two FRP-wrapped and insulated reinforced concrete columns tested by the National Research Council (NRC) of Canada. The results of finite element models showed less than 5% difference with the experimental results.

abstract: M.A.Sc.


title: Restoring a Neglected Queen: Re-Examining Catherine of Braganza's Role in the Restoration Period

contributor:
Collins, Jeffrey
History

subject:
English History
English Protestantism
English Catholicism
Catherine of Braganza
Charles II
The English Restoration
The Popish Plot
The Exclusion Crisis
English Divorce Law
Early Modern England
Early Modern Period

abstract: In her reign as Queen Consort, issues with Catherine of Braganza (1638-1705) brought up questions of power between the Church and State, helped heighten anti-Catholicism, and brought up questions of exclusion years before the infamous Exclusion Crisis began. History has traditionally remembered her for being the wife of Charles II, King of England, Scotland, Ireland, and Wales, and for bringing tea culture to England from her home, Portugal. This idea, however, neglects the more significant role she played in the Restoration Period (1660-1685). The Restoration resumed the issues between the Church of England and the State. The Church was desperate to demonstrate their autonomy from the State and their presumed divinity. The State wanted to use the Restoration to prove its presumed superiority over the Church of England through new legislation to weaken the Church’s control. Issues with Catholicism also became increasingly prevalent in the Restoration Period as Charles attempted to enact tolerant acts and Catholicism became closer to the royal family. This thesis will argue that Catherine is a neglected character in this story. Being Catholic, her presence at court became more of a nuisance as time went on. While keeping herself out of the spotlight, she still found ways to assist fellow Catholics and practise her faith as Anti-Catholicism rose. She was directly involved in the issues between Church and State, as ways to dispose of her brought up questions of secular and spiritual jurisdiction. As her marriage continued, it became apparent that she was not able to have children. Due to this, the King’s Catholic brother James remained the heir apparent. This worried Parliament and the Church, as both dreaded a Catholic taking the throne. To prevent a Catholic monarch, Parliament attempted to remove Catherine from her position byways of divorce and later impeachment. This thesis will demonstrate that when considering the Restoration Period, Catherine of Braganza is a main actor.

abstract: M.A.


title: Molecular Regulation of Mitochondrial Biogenesis in Exercised and Fasted Human Skeletal Muscle: an Examination of Emerging Regulatory Protein

contributor:
Gurd, Brendon
Kinesiology and Health Studies

subject:
Muscle Physiology
Skeletal Muscle
Mitochondria

abstract: The transcriptional co-activator PGC-1alpha is widely accepted as the “master regulator” of mitochondrial biogenesis – an increase in mitochondrial content – and much research has been devoted to understanding PGC-1alpha's role in mitochondrial remodeling. However, several studies have demonstrated the dispensability of PGC-1alpha for exercise-induced increases in mitochondrial content, highlighting redundancies in the molecular control of mitochondrial biogenesis. This dissertation attempts to advance our understanding of the molecular regulation of mitochondrial biogenesis in human muscle by examining the impact of exercise and fasting on regulatory protein with emerging roles in mitochondrial biogenesis. We first review the literature to critically evaluate the ability of PGC-1alpha to coordinate mitochondrial biogenesis in human muscle and highlight a number of regulatory protein that also appear important in the regulation of mitochondrial gene expression. Subsequent chapters examine how the expression of these protein is altered in skeletal muscle under various physiological conditions (e.g. rest, exercise, fasting). We demonstrate that the activation of Nrf2 – a transcription factor with an emerging role in mitochondrial biogenesis – coincides with the induction of genes involved in mitochondrial biogenesis after a single exercise bout and that changes in Nrf2 protein associate with changes in mitochondrial content after training. We also find that the expression of LRP130 – another emerging regulatory protein – is highest in human muscle fibers with a high mitochondrial content, localized to the mitochondria within individual fibers, and correlated with mitochondrial content at the whole-muscle level. Finally, although fasting does not robustly activate mitochondrial biogenic pathways in human muscle, Nrf2 protein expression is increased and changes in LRP130 and PGC-1alpha are coordinated in fasted muscle. Collectively, this dissertation highlights Nrf2 and LRP130 as important emerging regulators of mitochondrial biogenesis in human muscle, thereby warranting the further study of these protein in future work.

abstract: PhD


title: Outsourced Authoritarianism: The Commercialization of State Control in Chinese  Mayor’s Hotlines and the Internet-Opinion Industry

contributor:
Srivastava, Sarita
Sociology

subject:
China
State Control
Authoritarianism
Outsourcing

abstract: How is the market engaged in the grassroots governance of authoritarian China? My work addresses this question by exploring state-market collaborations in the industry of Internet control and the system of Mayor’s Hotline. Drawing on rich empirical evidence, including ethnographic observation, in-depth interviews, document analysis, my work finds that market actors are actively engaged in state control and government outsourcing is a critical mechanism promoting the state-market collaboration. I develop the concept of outsourced authoritarianism to describe the phenomena that authoritarian regimes rely on government outsourcing to incorporate private actors into the institutions of state control. My work detailed shows, by outsourcing the frontline control to private sectors, the tentacles of state control have touched a wider range of the social population. This finding challenges the traditional wisdom that authoritarian domination is monopolized by state actors and suggests a networked and multi-leveled understanding of authoritarian power. However, even though government outsourcing promotes the coordination between private actors and governments in the institutions of state control, it does not mean the profit motive of the market has been smoothly integrated into the control apparatus of the state. My evidence further demonstrates that outsourced authoritarianism also brings new governance problems. In both cases, the engagement of private actors proceeds through the mode of government outsourcing, which creates a dual-pressure structure under which frontline operators need to handle pressures from both the state and the market. I argue that this dual-pressure structure represents a special form of state-market complex within which the conflicting rationalities between authoritarian control and market profiting lead to dilemmas of governance at the grassroots level.

abstract: PhD


title: Policy to Practice: What Works to Meet the Needs of Families of Children with Disabilities in Bangladesh

subject:
Access
Bangladesh
Children with Disabilities
Family Needs
Government Support

abstract:
Introduction and objectives: Research on the needs of families of children with disabilities (CWDs) is sparse, particularly in low and middle-income countries such as Bangladesh. Further, little is known about factors that deter families from accessing government support. To address this gap, this multiphase study aimed to determine the extent to which the government offers support to meet the needs of CWDs and their families within disability policy; to explore the extent to which family members of CWDs have knowledge and access to government supports; to understand the experiences of family members of CWDs in accessing government supports; and to understand the perspective of service providers in implementing government support programs.
Method: To achieve these aims, I conducted a policy analysis using the 18 core concepts of disability policy (Phase I), a cross-sectional survey with 393 family members of CWDs (Phase II), a qualitative descriptive study with 27 family members of CWDs (Phase III), and a qualitative descriptive study with 21 service providers (Phase IV).
Results: Family members and service providers’ experiences together with the policy analysis revealed that the government of Bangladesh has made several commitments “on paper” to provide necessary support to meet the needs of families of CWDs. However, “in practice” families have limited access to government support due to obstacles including family members’ limited knowledge about government support, limited availability of support (e.g., lack of disability allowance and shortage of rehabilitation professionals), fragmented nature of support coupled with inaccessible physical environments, stigma, favoritism and perceived low quality of service.
iii
Conclusion: The results suggest that the government of Bangladesh, including practitioners need to educate families about available government support for CWDs. Additionally, practitioners should go beyond their clinical practice to that of an advocacy role and lobby with government to invest more resources to increase support for CWDs. Policymakers in Bangladesh need to strengthen monitoring and evaluation to minimize inequity in the implementation of disability specific programs. It is also important to address environmental barriers such as accessible infrastructure and public transportation. Finally, the Bangladeshi government should strive for greater coordination across all disability services.

abstract: PhD


title: Students with Physical Disabilities in High School Drama Education: Stories of Experience

contributor:
Bolden, Ben
Education

subject:
Physical Disabilities
Drama Education
High School
Teacher Support
Inclusion

abstract:
The dramatic arts have been shown to positively benefit students with disabilities; however, there has been little research examining how students with physical disabilities have experienced drama. Inspired by my own experiences from high school as someone with a physical disability, this narrative inquiry sought to understand the experiences of people with physical disabilities in high school drama education. I began by writing and analyzing my own stories to reflect on my experiences and understand my personal transformations. Data were then collected through semi-structured interviews with three participants who had taken part in drama education during their high school years. I asked participants to reflect on their experiences, as well as how drama had transformed them. Their stories were then written as narratives to present themes that emerged. Finally, participants were given the option to write monologues in response to the prompt, “What does drama mean to you as someone with a physical disability?” I then performed and recorded the monologues to better understand the intentions of the participants and make connections to their stories. Findings identified that participants had a positive experience as they built social connections with their peers and were able to explore their identities through playing different character. However, participants also described feelings of isolation and frustration at being overlooked for roles due to their disabilities.
This study aims to give voices to students with physical disabilities so that they may express their experiences and thoughts on disabilities and drama. It also seeks to help drama educators increase understanding how they can support the experiences of students with disabilities and how they can make their classrooms and programs more inclusive.

abstract: M.Ed.


title: Investigating the Receptor Interactions and Mechanisms of a Folic Acid-Conjugated Nanoparticle in the Treatment of Breast Cancer

contributor:
Szewczuk, Myron
Malardier-Jugroot, Cecile
Biomedical and Molecular Sciences

subject:
Nanoparticles
Breast Cancer
Folate Receptor

abstract: An area of intense research focus is the development of a highly specific drug delivery system (DDS) for anti-cancer agents. Chemical engineering of a “smart” DDS to specifically target tumor cells has gained interest in cancer research, designed for safer, more efficient, and effective use of chemotherapeutics for the treatment of cancer. However, the selective targeting and choosing the right cancer surface biomarker are critical for targeted treatments to work. The folic acid receptor alpha (FRα) has gained popularity as a potential target in triple-negative breast cancer (TNBC). We have previously reported on a functionalized folic acid (FA)-conjugated amphiphilic alternating copolymer poly(styrene-alt-maleic anhydride) (FA-DABA-SMA) via a biodegradable linker 2,4-diaminobutyric acid (DABA) that has the requisite features for efficient drug delivery. This biocompatible NP self-assembles in a pH-dependent manner, providing stimuli-responsive, active targeting, and extended-release of hydrophobic chemotherapeutic agents. We have demonstrated that this NP effectively penetrates the inner core of 3-dimensional cancer spheroid models to deliver anti-cancer agents. Interestingly, NPs not loaded with chemotherapeutics also decreased spheroid volume, revealing a previously unknown mechanism of action. The present study investigates the interactions, toxicities, and mechanisms of FA-DABA-SMA in TNBC. Results indicate a size-and-shape dependent interaction of the NP with FRα in which regular receptor functions are disrupted. Treatment with FA-DABA-SMA reduces expression of key proteins, including p53, the product of the highly mutated TP53 gene, and additional oncogenic proteins c-Myc, STAT3, HES1, and Notch1, which are all directly or indirectly influenced by FRα. Treatment with FA-DABA-SMA induces apoptosis and further causes a change in morphology in MDA MB-231 cells, as well as significantly reduces their ability to migrate. Collectively, the results of this study provide a novel insight into the FA functionalized NP that is attributed to a novel dual mechanism of action of targeting FRα and disrupting its regulation of several protein expression levels. This dual mechanism of FA-DABA-SMA demonstrates its effective therapeutic potential for the treatment of TNBC.

abstract: M.Sc.


title: Identification and Characterization of Novel Kinases Regulating Programmed Death Ligand-1 (PD-L1) in Immune Evasion of Triple Negative Breast Cancer Cells

contributor:
Yang, Xiaolong
Pathology and Molecular Medicine

subject: PD-L1

abstract:
The programmed death ligand-1 (PD-L1) is an immune checkpoint protein expressed on a variety of antigen-presenting cells to normalize immune system. Recently, overexpression of PD-L1 on the surface of cancer cells has been proven to contribute to cancer immune evasion and tumor progression. Specifically, PD-L1 is found highly upregulated in Triple negative breast cancer (TNBC), a subtype of breast cancer that currently has no effective clinical therapies, allowing blockade immune checkpoint therapy a potentially effective treatment. However, the overall response rate for PD-L1 targeted immunotherapy in PD-L1 positive TNBC is less than 20%. The mechanism for this is largely unknown. It has been suggested that the levels of many other genes regulating PD-L1 may contribute to the sensitivity of cancers to immunotherapy. Therefore, there is a critical need to understand how PD-L1 is upregulated and interacts with its upstream regulators in the modulation of anti-PD-L1 immunotherapy response in TNBC. Over the past years, the literature that implicated the regulation of PD-L1 was primarily on transcription levels. For this reason, my project aims to identify post-translational modification of PD-L1 in efforts to better target it in TNBC immunotherapy.
To identify novel kinase regulators of PD-L1, we first performed a proteomic analysis of PD-L1 and identified several tyrosine kinases as novel PD-L1 interacting proteins. We provide evidence that some of these kinases (EphA3, FAK, FES, and FER) could phosphorylate PD-L1 in vitro and co-expression of FAK, FES, and FER could stabilize PD-L1 in ectopic co-expression models. Moreover, FAK inhibition, knockdown, or ectopic over-expression resulted in decreased or increased PD-L1 levels, respectively; and that inhibition of EphA2 was associated with reduced endogenous PD-L1 levels. Most significantly, knockout of FAK in BT549  TNBC cells reduces immune evasion by inhibiting cancer cells-induced T-cell apoptosis in coculture experiments. In summary, we have identified several novel kinase regulators of PD-L1 stability and immune evasion. This is a critical first step in unveiling the molecular mechanism underlying PD-L1 upregulation in TNBC immune evasion and tumorigenesis. These findings present exciting opportunities for developing a new potential target and effective combinational therapies for immunotherapy-resistant TNBC.

abstract: M.Sc.


title: An Exploratory Analysis of Access to Specialist Dermatological Care in Ontario

contributor:
Rosenberg, Mark
Geography and Planning

subject: Health Geography Access

abstract: Access has been a significant issue within the discourse in health geography for decades (Wilson and Rosenberg, 2004; Harrington et al., 2013). In the Canadian healthcare system, access to dermatological services generally involves receiving a referral from a general practitioner to a dermatologist. Literature on dermatological care has revealed inequities and comorbidities associated with skin disease that require greater attention. This thesis is thus an exploratory project on access to dermatological care to see what might be found at this specific level of specialist care in Ontario. I surveyed 49 adults who had visited a dermatologist regarding a chronic skin disease. Responses were analyzed using four stages of quantitative analysis as well as qualitative analysis of open-ended survey responses. Simple logistic regression revealed that there were significant differences between respondents who saw a specialist relatively quickly and those who had to wait a longer time. The likelihood of having to wait longer for a dermatologist visit increased between the youngest and oldest age cohorts, which was consistent with the general literature on specialist access. The likelihood of having to wait longer also increased for high-income individuals and males. A one-way analysis of variance was conducted using mean self-reported scores from the Dermatology Quality of Life Index (DQLI). The differences between the means was significant, where stigma and cutaneous body image had the highest mean scores out of all areas addressed by the DQLI. As an exploratory study, the results cannot be considered conclusive but make the case that further research is required on how access to dermatological care fits within the broader context of equity in Canadian healthcare, as well as how it relates to psychosocial issues like stigma and body image.

abstract: M.A.


identifier: Rahman SMN. Preservation of Rat Digestive Tract by Phenol-based Embalming Solution. Kingston, ON: Department of Biomedical and Molecular Sciences, Queen's University; 2020

subject:
Histology
Embalming
Phenol-Based Embalming
Digestive Tract
Soft Embalming
Embalming Solution
Anatomy

abstract: The use of cadaver is most optimally simulated technique in surgical and anatomical training. The current standard formaldehyde fixation preserves cadaveric tissues for use for an extended period as compared to unfixed tissues. Still, it fails to maintain the natural color, texture, and biomechanical properties. Phenol based soft embalming methods were developed to preserve these qualities, while simultaneously reducing the biohazard risk. Soft embalming methods have made the bodies more ‘lifelike’ and better suited for training. There have been very few studies reported to date on the effects of phenol-embalming on tissue structure at the histological level. The current research project was designed to assess the preservation of the digestive tract with a phenol-based solution as compared with the classical formaldehyde fixation. The gross morphological changes and microscopic features of different parts of the digestive tube were noted. Various segments of the alimentary tract were harvested from adult rats. The fresh samples were dissected to obtain esophageal, small, and large intestinal tissues for phenol-based fixation and histological analysis after that. Control samples were fixed in routine 4% paraformaldehyde fixative. Following fixation, tissues were processed, stained with hematoxylin and eosin (H&E) or Masson’s trichrome (MT) for histologic analyses. Results showed that the digestive tract tissues fixed with phenol were much more flexible as compared to paraformaldehyde-fixation. Histologically, phenol-based fixation was comparable to that preserved by a paraformaldehyde-based solution. It was concluded that phenol-based solution is an excellent fixative used to preserve the digestive tract tissue for microscopic analysis.


title: Possible Mechanisms of Order Matching Effects in Attitude Persuasion

contributor:
Fabrigar, Leandre
Psychology

subject: Attitudes Persuasion Affect Cognition Order

abstract: The order persuasion matching effect occurs when the sequencing of information within a persuasive message matches that of the information used to generate said attitude. This matching effect generates stronger attitude change compared to mismatching conditions. This effect has been documented for decades, first appearing in early studies investigating the affective/cognitive structure of attitudes. The order persuasion matching effect was interpreted as evidence for affective/cognitive matching, but subsequent studies have called this interpretation into question, with the most recent research suggesting that the effect may occur due to a violation of expectations or preferences of the nature of persuasive information. The present studies’ goal was to provide more insight into the mechanisms driving the effect with focus on two non-exclusive interpretations. Study 1 explored the possibility that matching conditions enhanced processing via surprise at information that violated expectancies/preferences by manipulating argument quality to assess amount of processing across matching/mismatching conditions. Study 2 examined if the effect was a result of reduced counterarguing of persuasive information due to violation of expectations by employing arguments. Participants were presented arguments of ambiguous quality, which was expected to produce stronger counterarguing effects compared to strong or weak arguments. Both studies presented null findings counter to initial predictions; as a whole, the order persuasion matching effect was not observed in either experiment.

abstract: M.Sc.


title: Investigating the Role of LPS-Induced Neuroinflammation as a Potential Mechanism of Anhedonia

contributor:
Olmstead, Mary
Olmstead, Mary C.
Psychology

subject:
Anhedonia
Reward Responsiveness
Neuroinflammation

abstract: Anhedonia, a deficit in reward processing, is a characteristic of many neuropsychiatric conditions including eating disorders, schizophrenia, substance use disorder and major depressive disorder (MDD) (American Psychiatric Association, 2013).  Literature suggests a relationship between inflammation and MDD, as individuals with MDD have increased levels of pro-inflammatory cytokines (Zunszain et al., 2012).  The relationship between MDD and inflammation has been studied, however inflammation and anhedonia has been studied less extensively.  The goal of the current study was to investigate the relationship between neuroinflammation, induced by lipopolysaccharide (LPS) administration, and anhedonia in rats using the probabilistic reward task (PRT).  In this task, rats learn to discriminate between two ambiguous stimuli for a sucrose reward.  During testing, one lever is rewarded three times more than the other lever.  Similar to humans, rats develop a response bias for the stimuli that is rewarded more frequently regardless of the tone that was presented.  Seven days following LPS administration, rats were tested in the PRT: both SAL- and LPS-treated animals developed a response bias.  The results did not indicate a deficit in reward learning in LPS-treated animals, however this does not mean that a relationship between inflammation and anhedonia does not exist.  Systemic LPS administration to induce neuroinflammation may not be a successful model when testing for anhedonia.  Future studies investigating the relationship between inflammation and anhedonia may need to use other models of inflammation in order to examine this relationship.

abstract: M.Sc.


title: Atomically Precise Metal Clusters: Synthesis, Excited State Dynamics, and Unique Optical Properties

contributor:
Stamplecoskie, Kevin
Chemistry

subject:
Metal Clusters
Optical Properties
Solar Cells
Photochemistry
Photocatalysis
Two Photon Absorbance
Transient Absorption Spectroscopy
Atomic Precision
Bbimetallic Metal Clusters

abstract:
Metal clusters are small particles with the exact number of metal atoms and the number/type of ligand molecules bound to the surface. The optical and electronic properties of these materials can be tuned and controlled with precise synthesis. These materials exhibit phenomena such as fluorescence and molecule-like light absorbance. Owing to the unique optical properties of clusters, this new class of materials is finding applications in solar energy harvesting, chemical sensing, biomedical imaging and catalysis. Partly due to their extremely small size, properties like absorbance, HOMO-LUMO energy gap, and fluorescence lifetimes/quantum yield can be tuned through minor changes in either the metal or the coordinating ligands. The electronic properties of clusters can be characterized using spectroscopic techniques that provide valuable information on the ability to absorb light, fluorescence capabilities, and excited state behavior, and so on. All of these factors are critical in dictating photocatalytic activity. These clusters can be functionalized with peptides, which makes them ideal for use in biomedicine as well. The nonlinear optical properties of these clusters make them excellent candidates for use in next generation biomedical imaging and therapy.
In this thesis:
•	A photochemical route for producing atomically precise gold clusters is reported.
•	Electronic properties (i.e., HOMO energy) and the wavelength-dependent photocatalytic activity of glutathione protected clusters have been investigated with photovoltaic experiments.
•	The excited-state properties of Au18(SR)14 clusters are studied in-depth by ultrafast pump/probe spectroscopy and a single model describing the optical characteristics of thiol protected Au18(SR)14 and Au25(SR)18 clusters is offered.
•	Au-Ag alloy clusters and their photophysical and photocatalytic activity have been studied and compared to monoatomic Au and Ag clusters.
•	Using pump/probe femtosecond transient absorption spectroscopy, we have probed the two-photon absorbance of 11 different Au and Ag clusters which allows us to draw conclusions on the role of the particular metal, cluster size/structure, and the effects of the 2PA behavior of clusters. The dramatic effect of excitation wavelength and how double resonance mechanism leads to different non-linear responses has been investigated.
Overall, the content of this thesis describes the importance of precise synthesis of metal clusters and how different clusters with unique optical and electronic properties can be advantageous in various research areas.

abstract: PhD


title: Anisotropic Fluid Solutions to Einstein's Equations in Spherical Symmetry

contributor: Physics, Engineering Physics and Astronomy

subject:
Anisotropic Fluid
General Relativity
2M/R
Equation of State
Relativistic fluid

abstract: The main objective of this thesis is to develop and investigate a class of spherically symmetric solutions to Einstein's field equations for anisotropic matter distributions. This work is partially motivated by a recent theorem of Andreasson \cite{ha1}, on the upper limit of the tenuity ratio for objects possessing equations of state of the form $p_r+ 2 p_t = \Omega \rho$, where $p_r, p_t$ and $\rho$ are the radial pressure, tangential pressure and energy density, respectively and $\Omega$ is an unspecified constant characteristic parameter of the fluid. An immediate goal was to extend this theorem to the broader class of all linear barotropic equations of state. A solution generating algorithm which yields infinitely many analytical, physically reasonable, stable fluid distributions for general linear barotropes (with and without the cosmological constant $\Lambda$) is presented and analyzed. Other general aspects of spherical anisotropic matter distributions are discussed, including historically significant developments, wave propagation and stability.

abstract: M.Sc.


title: The Role of von Willebrand Factor in the Pathogenesis of Deep Vein Thrombosis in Acute Inflammation

contributor:
Lillicrap, David
Pathology and Molecular Medicine

subject:
von Willebrand Factor
Deep Vein Thrombosis
Immunothrombosis
Inflammation

abstract: Venous thromboembolism, comprised of deep vein thrombosis (DVT) and pulmonary embolism, is a thrombotic cardiovascular disease that accounts for a significant portion of the global health burden. Among its risk factors, inflammatory states such as sepsis and more recently, COVID-19, have been correlated with increased DVT risk. Combined with the prevalence of breakthrough VTE incidences despite thromboprophylaxis, inflammation-associated venous thrombosis raises significant clinical concerns for hospitalized patients. Mechanistic insights into the link between these pathologies were consolidated with the introduction of immunothrombosis, whereby the dysregulation of the interplay between the innate immune system and thrombosis could contribute to pathological thrombosis. For example, the uncontrolled release of immune mediators such as cytokines can lead to endothelial dysfunction. This in turn can result in the upregulation of prothrombotic mediators such as von Willebrand factor (VWF), a multimeric hemostatic protein with well-documented roles in hemostasis. Indeed, increased levels of plasma VWF have been reported in inflammatory diseases such as sepsis, while the critical role of VWF in venous thrombogenesis has previously been demonstrated. However, whether VWF plays a role in mediating inflammation-associated venous thrombosis has not been elucidated. Therefore, using the previously established murine inferior vena cava stenosis model of DVT, we aimed to investigate the role of VWF in venous thrombosis concurrent with lipopolysaccharide-induced endotoxemia. We hypothesized that an inflammation-induced increase in plasma VWF levels would enhance DVT development. In our model, we show that endotoxemia does significantly increase thrombosis incidence, concurrently with elevated plasma VWF levels. Using inhibitory antibodies, we further confirm that VWF inhibition produces a protective effect against thrombosis incidence in endotoxemia. Our histological analyses using a mass cytometry imaging approach demonstrate that VWF assumes a distinct localization pattern that coincides with fibrin and markers of neutrophil extracellular traps, recognized to comprise the thrombus scaffolding network. This localization pattern remains relatively stable despite endotoxemia, demonstrating that despite thrombus heterogeneity, the scaffold remains constant. Overall, our findings suggest significant pathogenic implications for the clinical management of inflammation-associated venous thrombosis, which may be of especially high relevance in the current landscape of the COVID-19 pandemic and its associated highly thrombotic coagulopathy.

abstract: M.Sc.


title: Investigating Teachers’ Perspectives on Using Students' First Language in the English as a Second Language Classroom in Guangzhou China

contributor:
Myers, Maria
Education

subject:
Teachers’ Perspectives
Monolingual Approach
Bilingual Approach
Teaching Practice
Individual Factors

abstract: The widely-used monolingual approach, meaning avoiding or minimizing first language (L1) use in classrooms, by increasing the input in the second language (L2) in the course of learning can effectively develop students’ comprehension skills (Krashen, 1981; Genesee, 1978). However, the monolingual approach could not explain the transfer that happens between the L1 and L2. Different theories suggested different outcomes for the transfer between the L1 and L2. Studies investigating students’ opinions on using the L1 in L2 learning indicated that the L1 was necessary in classrooms (Dujmović, 2014; Schweers Jr., 1999; Tang, 2002). However, not many studies were conducted to investigate teachers’ perspectives on using students’ L1 in English language learning. Therefore, this study examines how teachers perceive the role of students’ L1 in English language learning and the related practices. The methodology for the study follows Tang’s (2002) research by first collecting teachers’ opinions through surveys with follow-up interviews. 18 middle-school English teachers in Guangzhou, China took the questionnaire and ten of them participated in the follow-up interview. The questionnaire provided an overview and the interview results were analyzed using theoretical frameworks by Krashen (1981) and Cook (2002). The results indicate that most of the participants would apply Krashen’s (1981) Input Hypothesis in teaching to gradually reduce the amount of the L1 used in the classroom and provide input for learning although they offered an adaptation. While all of the participants would allow the use of students’ L1 in explicit conditions, some participants observed that certain skills can be accessible in both the L1 and L2. Teaching experience influenced the participants more than the L2 learning experience. Two major implications for practice could be concluded from the results. First, the L1 is helpful in explicit learning and maintaining a low affective filter while minimizing the L1 allows the students to get used to an L2-speaking environment. Second, ongoing support and reflection in teaching provides teachers with a positive development of their professional experience. Future research on a larger scale on those mechanisms is suggested to further establish the trustworthiness of those results.

abstract: M.Ed.


title: Validation of a Markerless Motion Capture System for Human Movement Analysis

contributor:
Deluzio, Kevin
Mechanical and Materials Engineering

subject:
Human Movement Analysis
Markerless Motion Capture
Gait Analysis
Human Biomechanics

abstract: Three-dimensional human movement analysis is a widely used tool in clinical and research biomechanics to provide comprehensive 3D representations and quantification of individuals’ movement patterns, particularly gait. Marker-based optical motion capture is the current ‘gold standard’ for performing human movement analyses; however, these systems have several inherent issues that affect the accuracy and reliability of their data and limit the environments in which data can be collected. Markerless motion capture is a quickly evolving technology that has the potential to eliminate many of the issues associated with marker-based motion capture. This research aims to validate a deep neural network-based markerless motion capture system, Theia3D, against a current field-accepted marker-based motion capture system for human gait. Three studies were undertaken towards the validation of this technology: (i) a comparison of time- and distance-based gait parameter measurements obtained simultaneously by the markerless and marker-based motion capture systems; (ii) a comparison of kinematic measurements obtained simultaneously by both systems; and (iii) a multi-session study of the repeatability of kinematic measurements obtained by the markerless motion capture system. The results of these studies indicate that this markerless motion capture system can measure time- and distance-based gait parameters and gait kinematics with sufficient accuracy for use in research and clinical applications, and the kinematic measurements were more reliable than those previously reported for ‘gold standard’ marker-based motion capture systems. These findings indicate the markerless motion capture system is sufficiently accurate and reliable for use in clinical and research biomechanics and can potentially reduce the limitations previously associated with performing human movement analysis.

abstract: M.A.Sc.


title: Exploring Digitalization in New Venture Ecosystems – Three Essays

contributor:
Chan, Yolande E.
Business

subject:
Digitalization
Digital Entrepreneurship
Digital Innovation
New Venture Ecosystem

abstract: Despite significant business opportunities made possible through digital technology advancements, readily available digital technologies such as social media, mobile technologies, analytics, and cloud computing (SMAC) are often overlooked and not used by many new ventures. This thesis looks at digital entrepreneurial affordances created through interactions between goal-oriented new ventures and readily available digital technologies to address this problem. In particular, this thesis identifies several affordances and explores the actualization process of these digital entrepreneurial affordances over time to develop dynamic capabilities in new ventures. Exploratory multiple case studies are used. The first paper in this thesis examines the characteristics of readily available digital technologies and the goals of new ventures to identify digital entrepreneurial affordances that can enable dynamic capabilities. The second paper builds on the findings of the first paper, using a configurational approach to explore the actualization process of the identified affordances to further identify patterns of dynamic capability building at new venture ideation and development stages. Finally, the third paper examines interrelated bundles of digital entrepreneurial affordances that can result in the development of technology-enabled dynamic capabilities and higher firm performance.

abstract: PhD


title: Theoretical Investigation of Ice-Shedding Coatings

contributor:
Liu, Guojun
Chemistry

subject: Ice-Shedding Theoretical Coating Polymers

abstract:
Theoretical studies into the properties of ice-shedding coatings allow for their development time to be reduced by suggesting avenues to approach for development based on their fundamental properties. The aim of this thesis is to model the behaviour of lubricant-swollen polymer gels and a similar gel with a grafted brush layer to evaluate them as ice-shedding coatings.
Syneresis, the mechanism behind the lubricant-swollen polymer gels, was modelled using a modified version of the Flory-Rehner equation. The mechanism was shown to be dependent on three parameters, the crosslinking density of the coating, the degree of polymerization for the lubricant, and the amount of lubricant swelling the system. Increasing any of the parameters was shown to increase the temperature for the onset of excretion, as well as the amount of excretion at a given temperature. The failure mechanism for these coatings was predicted to be the point where enough lubricant has been lost that syneresis does not occur within the operating temperature range of the coating. In addition, a coating has been proposed where the crosslinking density and degree of polymerization will dynamically increase with decreasing temperature using H-bonding to improve the efficacy of the excretion.
The lubricant-swollen polymer gel with a brush layer was modelled as a crosslinked matrix bound to a substrate with a grafted brush layer being swollen by a lubricant. The matrix used the modified Flory-Rehner equation, while the brush layer was modelled using a mean-field theory from literature. The system was shown to have two regimes: a sub-excretion regime and an excretion regime. In the excretion regime, the lubricant-swollen polymer gel with a grafted brush layer was predicted to react similarly to the coating without a grafted brush layer when changing crosslinking density and degree of polymerization. In the sub-excretion regime, the coating was predicted to have lubricant shift from the matrix to the brush layer given a decrease in temperature. This shift allows the coating to act as a low-interfacial toughness material should the coating be unable to undergo syneresis.

abstract: M.Sc.


title: Application of Nano-Scale Characterization Techniques in Failure Analysis of Stress Corrosion Cracking in an Alloy C-276 Pull Rod

contributor:
Persaud, Suraj
Mechanical and Materials Engineering

subject:
Stress Corrosion Cracking
Hastelloy C-276
Transmission Electron Microscopy
Scanning Electron Microscopy
Focused Ion Beam
Transmission Kikuchi Diffraction
Slot-Tunnel Corrosion

abstract: A failure analysis was performed on an alloy C-276 pull rod which underwent unexpected brittle, fracture after exposure to nuclear-relevant, high temperature aqueous environments: Pb-contaminated alkaline (8.5 < pH300C < 9.5), and sulfate-containing acidic solutions (3.0 < pH300C < 5.0). The component was characterized using advanced electron microscopy methods to demonstrate the benefits of these techniques for determining the nanoscale chemical and material factors contributing to stress corrosion cracking (SCC), and to provide insight into the mechanism of failure.  Site-specific transmission electron microscopy samples containing crack tips were prepared using a focused ion beam. Nanoscale chemical characterization methods revealed that Pb was present in some oxidized regions of cracks, suggesting that the element may be inhibiting or impairing the passivity of the Cr-rich oxide. Complementary nanoscale microstructural analysis was performed. At an intergranular to transgranular cracking mode transition, it was observed that the transgranular crack (and corrosion process) propagated along the (110) crystallographic plane. Also, the cracking mode was highly dependent on the tensile stress direction relative to grain boundary orientation, the crystallographic orientation of grains, and slip systems. A comparison of results with proposed mechanisms for SCC of Ni alloys in similar environments are discussed; the highly directional nature of cracking is consistent with a slot-tunnel corrosion mechanism.

abstract: M.A.Sc.


title: Assessment of Rockfall Deformation and Related Geometric Characteristics via Terrestrial Laser Scanning

contributor: Geological Sciences and Geological Engineering

subject: LiDAR Rockfall

abstract:
Due to the required numerous and extensive rock cuts through steep topography and adjacent steep natural slopes, rockfalls are a common risk to which the Canadian National Railway (CN) and Canadian Pacific Railway (CP) rail corridors in Western Canada are exposed, which can result in  economic or human losses in the event of a track blockage or derailment.  Some rockfall blocks demonstrate pre-failure deformation prior to their release from the slope which can be detected via analysis of 3D point clouds obtained via repeated terrestrial laser scanning (TLS). Understanding what factors affect the likelihood and magnitude of a future rockfall’s pre-failure deformation, and subsequent establishment of expected deformation thresholds, may prove useful for hazard management. The research presented herein has several objectives: (1) Develop a workflow for the semi-automated assessment of rockfall pre-failure deformation via roto-translation, (2) Validate the accuracy of the roto-translation algorithm, (3) Develop algorithms to objectively assess rockfall block and post-failure scar geometric properties from 3-dimensional point cloud data, and (4) Populate a database containing deformation and geometric characteristics of past rockfalls and investigate correlations between these sets of properties.
This study utilizes TLS data collected on average every three months from May 2013 to March 2019, at an active rock slope above a rail line in the Thompson River valley in British Columbia, Canada. A database of 55 rockfalls was populated, including both pre-failure deformation and geometric properties. Eighty-seven percent of these events demonstrated detectable pre-failure deformation. When considering all rockfall events in the database simultaneously, the strength of correlations between geometric and deformation parameters was limited. The only correlation strong enough to support identification of potential parametric deformation thresholds was between pre-failure toppling magnitude and rockfall volume. Rockfalls at this site with shallowly dipping sliding planes and high volume will in general be expected to have comparatively lower levels of detectable pre-failure deformation, especially toppling if the sliding plane is shallow, and will leave behind a relatively smooth sliding plane if significant pre-failure toppling occurs.
The high frequency of rockfalls demonstrating detectable pre-failure deformation is promising for the feasibility of future application of monthly-scale TLS and iterative-closest-point roto-translation techniques for the monitoring of rockfall pre-failure deformation. However, if time-to failure is to be reliably estimated, there must be a greater understanding of what environmental factors and/or geometric characteristics are correlated with the onset and duration of the tertiary acceleration phase of creep.

abstract: M.A.Sc.


title: Characterization of GM- and M-CSF-Derived Macrophages Response to Lymphocytic Choriomeningitis Virus Infection and TLR7 Agonist

contributor:
Basta, Sameh
Gee, Katrina
Biomedical and Molecular Sciences

subject: LCMV GM-CSF M-CSF Macrophages TLR7 R848

abstract:
Macrophages (MΦ) are innate immune cells considered as the primary line of defense during infection and as controllers of tissue homeostasis. In response to viral infection, MΦ induce cytokine production and regulate adaptive immunity via antigen presentation to T cells. Granulocyte-macrophage colony-stimulating factor (GM-CSF) and macrophage colony-stimulating factor (M-CSF) are two key cytokines needed for the differentiation of MФ. M-CSF MФ have been used as models to study virus infection; however, the responses to viral infection by GM-CSF MФ have not been well characterized.
	We evaluated the production of cytokines by MФ in response to two strains of lymphocytic choriomeningitis virus (LCMV), LCMV Armstrong (LCMV-ARM) and LCMV clone 13 (LCMV-Cl13). We found that LCMV-Cl13 and -ARM infection induced the production of different patterns of pro-inflammatory cytokines, including IL-6 and TNF-α, but failed to produce IL-12p70 and IL-23 by GM-CSF MФ. Conversely, M-CSF MФ induced more anti-inflammatory cytokine IL-10. Moreover, these MФ responded differently to the viral strains; with LCMV-ARM, GM-CSF MФ and M-CSF MФ induced high IL-6 and IL-10, respectively, whereas LCMV-Cl13 GM-CSF MФ generated more TNF-α.
	Since TLR7 is one of the main innate immune receptors that recognise ssRNA viruses, we examined MФ responsiveness to TLR7-mediated signaling pathways after LCMV-ARM infection following R848 (resiquimod) treatment. We found that R848-mediated signaling molecule activation was reduced in both MФ subsets during the early infection. However, GM-CSF MФ induced higher pro-inflammatory cytokine expression (e.g. IL-6, TNF-a, and IL-12p40) and M-CSF MФ exhibited higher anti-inflammatory cytokine expression (eg IL-10). Moreover, TLR7 expression was maintained in M-CSF MФ in response to LCMV infection and increased in GM-CSF MФ, but TLR7 expression was partially decreased in response to R848 treatment in both M-CSF and GM-CSF MФ.
Finally, we tested antagonism between GM-CSF and M-CSF in cultures of MФ with varying ratios of M-CSF:GM-CSF. We observed that GM-CSF can be dominant over M-CSF in terms of MФ polarization, cytokine production, and MФ morphology. We showed that only minimal GM-CSF in the mixed culture ratios resulted in MФ polarization towards an M1 phenotype, with regards to NO production, cytokines induction, and MФ morphology.

abstract: PhD


title: Bullying Victimization and Subjective Health Complaints in Canadian Adolescents: Examining Spiritual Health Connections as Protective Heath Assets

contributor:
Pickett, William
Public Health Sciences

subject:
Violence
Bullying
Epidemiology
Spiritual Health
Subjective Health Complaints
Adolescents
Resilience

abstract:
Background: Young people victimized by bullying may draw on assets such as spiritual health to protect them from harm. Composed of the connections in our lives (to ourselves, others, nature, or something transcendent), spiritual health may moderate pathways between bullying and symptoms of poor mental health, but this has yet to be explored among adolescents.
Objectives: 1) Examine the structural validity of a 10-item Spiritual Health scale; 2) describe patterns in bullying victimization, health complaints and spiritual health; and 3) investigate if spiritual health connections act as effect modifiers in relationships between bullying victimization and subjective health complaints, as one indicator of impaired internalizing mental health. Differences between age and gender groups were also explored.
Methods: Data were used from the 2017/18 Canadian Health Behaviour in School-aged Children study. Objective 1: Factor analyses examined the structural validity of the 10-item Spiritual Health Scale. Objective 2: The prevalence of key variables was examined in different age and gender groups. Objective 3: Modified Poisson regression models with robust error estimation were used to estimate the relative risk for the association between bullying victimization and subjective health complaints. These models also estimated effect modification by spiritual health in age and gender groups.
Results: Objective 1: The latent structure of the Spiritual Health scale was consistent with the four theoretical domains. Objective 2: 21% of the total sample reported being bullied, with a higher prevalence among girls and younger students. Objective 3: Among girls, the strength of “connections to self” was found to act as an effect modifier. The strongest associations between bullying victimization and frequent health complaints were identified among girls with high connections to self. Relative risks for health complaints among these self-connected girls were 1.63 (95% CI: 1.26-2.12) and 1.25 (1.06-1.47) for younger and older girls, respectively. The same relationship was weaker in girls who placed lower importance on connections to self.
Conclusion: Relationships between bullying victimization and frequent health complaints differed by the strength of “self-connections”, suggesting effect modification. Associations were strongest among girls reporting high importance of connections to self. This may have implications for future adolescent health promotion.

abstract: M.Sc.


title: Entry-based Planning of Neurosurgical Trajectories

contributor:
Ellis, Randy E
Computing

subject:
neurosurgery
ventriculostomy
image processing

abstract:
Purpose In cases of brain trauma or hydrocephalus an external ventricular drain (EVD) is often inserted through the skull and brain to drain excess cerebrospinal fluid from the ventricles to relieve pressure. Most often, EVDs are inserted free-hand, without guidance, at a point on the skull named Kocher’s point, perpendicular to the skull surface. Previous freehand EVD insertion studies have reported insertions in ideal target locations in only 40-50% of cases. We developed a visualization method to identify regions on the skull surface that will result in successful intersection with the ventricles during the ventriculostomy procedure, while also allowing for pre-calculated uncertainties in the trajectory.
Methods Using preoperative head CT scans, we estimated entry sites on the skull surface giving surgeons the best chance of reaching the ventricles, while incorporating uncertainty between 5 and 10 degrees. We performed a technical feasibility trial on 60 retrospective ventriculostomy patient cases consisting of hydrocephalus and traumatic brain injury patients and compared to 30 retrospective asymptomatic patient cases. The method was evaluated by calculating the portion of trajectories still feasible after incorporating uncertainty, and by comparing the calculated average catheter length to the typical catheter length measured in ventriculostomy studies.
Results There was no significant difference in hit rate (HtR) between hydrocephalus and trauma patients for the region of high accuracy and the region of high dispersion (p = 0.49, 0.32). There also was no significant difference in catheter length between hydrocephalus and trauma patients for the region of high accuracy (p = 0.17) and the region of high dispersion (p = 0.16).
Conclusion A new planning system to perform ventriculostomies was created to help facilitate decision-making in regard to the site of insertion of EVDs. The visualization tool identifies new insertion sites but also confirms the validity of existing insertion sites used in the current standard of care. The average simulated catheter length measured falls within the accepted depth at which EVDs are measured to be inserted into the brain.

abstract: M.Sc.


title: Fire activity in northeast Ontario during the Holocene as inferred by sedimentary macrocharcoal

contributor:
Cumming, Brian
Biology

subject:
charcoal
macrocharcoal
paleofire
Holocene
Boreal forest
HTM
Holocene Thermal Maximum
charcoal morphology
charcoal morphotypes

abstract:
Wildfire management can benefit from knowledge of past wildfire response to changing
environmental conditions. We extracted a high-resolution macrocharcoal record from a small deep lake
with a relatively small watershed in northeastern Ontario to examine evidence of fire activity in the area
over the last 6,300 cal yBP. Peak analysis of the macrocharcoal sequence showed a relatively stable
average fire return interval (FRI) of 155-183 years from the Holocene Thermal Maximum (HTM) till
present. Although the FRI remained relatively stable, charcoal accumulation rates, background charcoal
levels, and peak magnitude varied between periods of substantial change in vegetation delineated by
pollen analysis including a period of maximum warmth from c. 6,300 to 3,600 years before present when
pollen-inferred temperatures were ~2ºC warmer than present. Overall high charcoal levels coupled with
high variability occurred during this warm and humid HTM Period while charcoal levels were
consistently low during the cool and dry Post-HTM Period (3,600 – 1,600 cal yBP). Charcoal levels
increased and became variable again during the cool and wet Modern Period (1,600 cal yBP – present)
but did not reach the high concentrations observed in the HTM. The variation of charcoal levels within
pollen-inferred climate zones showed that wildfire activity on the regional-to-local scale (such as fire
size) changed in response to climate and vegetation despite relatively stable FRIs. In addition, charcoal
morphology was quantified and compared to the climate zones and showed distinct trends in relative
abundances of morphological particles in the different climate periods.

abstract: M.Sc.


title: COMPUTATIONAL IMPLEMENTATION OF THE INCENTIVE -SENSITIZATION THEORY OF ADDICTION

contributor:
Olmstead, Mary
Psychology

subject:
addiction
computational modelling
Nengo AI
incentive sensitization

abstract: In the mid-1990s, the disease model of addiction replaced the moral model, emphasizing the underlying neurological mechanism of addiction. In accord with this view, the Incentive-Sensitization theory provides an account of compulsivity in addiction by emphasizing neural changes that accompany chronic drug use. This thesis presents the first steps towards a biologically grounded implementation of the Incentive-Sensitization theory of addiction. First, this project proposes an update of computational model structure with a learning perspective of addiction, focusing on the Incentive-Sensitization process. This project then presents multiple different plausible ways of mapping this theory onto a computational model, and examines the resulting behaviour to see whether it accords with standard interpretations of the theory. Results showed that, while repeated drug use can lead to a sensitized mesolimbic dopamine system, associative learning hyperreactivity to drug cues is crucial for the development of chronic drug use. Analyses of the computational models also revealed important ambiguities and limitations to the Incentive-Sensitization theory. This is the first step in a larger project to create a computationally tractable and biologically motivated computational model of addiction to help clarify and ground various terms in the theory.

abstract: M.Sc.


title: Rhodium-Catalyzed Carbocyclization Reactions of Alkylidenecyclopropane-Tethered Dienes

contributor:
Evans, P. Andrew
Chemistry

subject: Rhodium-Catalyzed

subject: Carbocyclization Reaction

subject: ACP-tethered

subject: [3+2+2]

subject: [3+2]

abstract:
Higher-order transition metal-catalyzed carbocyclization reactions represent an important class of reactions for the construction of complex polycyclic scaffolds not attainable by conventional pericyclic reactions.   The following thesis outlines our efforts in the development of a novel rhodium-catalyzed carbocyclization reaction for the construction of both 5,5- and 5,7-bicyclic scaffolds, inherent within the scaffolds of many biologically active natural products.  This thesis is divided into two chapters:

Chapter 1 first highlights key developments in our understanding of the reactivity of transition metals towards alkylidenecyclopropane (ACP) and their derivatives.  This pioneer work sets the stage for the systematic review of significant advances in metal-catalyzed [(3+2)] and [3+2+2] carbocyclization reactions involving ACP-tethered substrates that follows. The limitations of these advances, specifically with respect to recent advances in the [(3+2+2)] and [(3+2)] carbocyclization reactions, set the stage for our development of rhodium-catalyzed variants of these processes in Chapter 2.

Chapter 2 highlights our efforts in the development of highly regio- and diastereoselective rhodium-catalyzed [(3+2)] and [(3+2+2)] carbocyclization reactions of ACP-tethered dienes.  First, we describe our development of robust reaction conditions for both the [(3+2)] and [(3+2+2)] processes.  Secondly, we demonstrate the extension of our developed methodology towards a broad diversity of synthesized ACP-tethered dienes.  Thirdly, we present our efforts towards an enantioselective [(3+2+2)] transformation using a novel rhodium chiral diene complex.  Lastly, we discuss future developments in the preceding processes.

abstract: M.Sc.


title: Dysphoria as a Moderator of Online Self-Presentation Via Image Selection

subject:
dysphoria
online self-presentation

abstract: The current research consists of two studies to examine the relationship between dysphoria (i.e., subclinical depression or chronic negative mood) and visual self-presentation online. In Study 1, I compared dysphoric and nondysphoric participants’ profile pictures from three different social networking sites (Facebook, Twitter, and Instagram) and found that greater dysphoria was related to engaging in more honest self-presentation strategies (e.g., selfies) in online self-presentation. In Study 2, I assessed the similarity of dysphoric and nondysphoric participants’ avatars to themselves and if identification with the avatar moderated this relationship. Greater dysphoria was related to creating avatars that were less physically similar to themselves, but identification did not moderate this relationship.

abstract: M.Sc.


title: Normal Order of Certain Arithmetic Functions and New Analogues of the Erd\H{o}s-Kac Theorem

contributor:
Murty, Ram
Mathematics and Statistics

subject:
Number Theory
Probabilistic Number Theory

abstract: In 1917, Hardy and Ramanujan planted the seeds of Probabilistic Number Theory when they defined `normal order' of an arithmetic function. This was nurtured further by Erd\H{o}s and Kac and many other great minds who infused further improvements to the probabilistic theory of additive functions. A systematic generalisation of this study to non-additive functions was initiated by Ram Murty and Kumar Murty in 1984. In this thesis, we study the theorem of Hardy and Ramanujan more deeply from a different perspective where we view the normal order results as estimates on sizes of certain exceptional sets. Using these results, we study the normal order of various non-additive functions like $\Omega(\phi(p+a))$ and $\Omega(\tau(p+a))$, thus generalising the results of Murty and Murty to shifts of prime arguments. We also study the distribution of these functions. Here $\Omega(n)$ counts the number of prime factors of a natural number $n$, with multiplicity, $\phi(n)$ denotes the Euler totient function and $\tau(n)$ denotes the Ramanujan tau function. Here and throughout the thesis, we denote $p$ as a prime. Finally, we study the moments of Dirichlet characters and establish normal order results in that direction as well.

abstract: PhD


title: The Performance of Reinforced Concrete Pipe Joints under Differential Ground Settlement

contributor:
Moore, Ian
Civil Engineering

subject:
Pipe
Joint
Leakage
Differential Ground Settlement

abstract: Leakage from reinforced concrete pipe joints has negative environmental impacts and can compromise the sewer or culvert’s service life. Pipes can fracture, corrode, rotate, experience joint pullout, and potentially undergo damage during their installation – leading to leakage into or out from the pipe. Reinforced concrete pipes are a common pipe used for waste and storm water transmission and have been proven to be a durable, easily constructed pipe choice throughout modern history. Reinforced concrete pipelines utilize gasketed bell and spigot joints, forming a push fit joint. Joints allow a pipe to accommodate some deformations while maintaining functionality, however, joints also form a point of weakness at which the sealing properties can be compromised with permanent ground deformation. This research project examines 600 mm internal diameter reinforced concrete pipes for joint capacity and response to imposed demands. The key objective of the research was to quantifying rotations and shear forces acting across the joints, as these demands are not readily used in the design of reinforced concrete pipes. Two, multi-segmented pipelines were used for experimentation in buried and unburied environments. Tests were conducted in the Split Box and Joint Articulation Frame at Queen’s University to impose controlled distortions to the pipe joints and barrels. The Split Box was used to subject a three-segment pipeline to a normal fault as a proxy for various forms of permanent ground settlements. The pipe, under an external pressure of 45 kPa, did not leak at a maximum fault offset of 150 mm, however, peak demands were quantified as 2.66 degrees and approximately 0.6 kN of shear force. Local shear force across the joint resulted from rotation rather than shear displacement. The Joint Articulation Frame was used to induce rotation and shear force in the joint of a two-segment pipeline at different external pressures. Pure rotation and shear experiments were conducted in the work to define the leakage limits. The rotational serviceability limit was found to be between 4.8 and 5.2 degrees. Shear limits were not isolated due to equipment limitations but points of successful joint function below the leakage limit were revealed. Simple joint capacity envelopes were developed, which indicate demand combination ranges that yield acceptable joint performance.

abstract: M.A.Sc.


title: Parenting in Adversity and Individual Perceptions of (In)Access to Health and Social Support Services: A Sensemaker® Study

contributor:
Davison, Colleen
Power, Elaine
Kinesiology and Health Studies

subject:
Health Promotion
Public Health
Parenting
Adversity
Lived Experiences
Service Accessibility
Health Care Services
Social Support Services
Sensemaker®

abstract: Having access to services for health and social support has been shown to greatly affect the health and well-being of individuals, communities, and society globally. However, great disparities in accessing services exist across sub-populations. Evidence indicates that individuals living in adversity in Canada have inequitable access to health and social services. This research focused on Canadian parents experiencing varying levels of adversity in Kingston, Ontario. The three main objectives were: 1) To explore the relationship between a parent’s self-reported adversity and their perceptions and experiences of accessing health and social services in Kingston, Ontario; 2) To describe the ways adversity might create barriers and facilitate opportunities for access to health and/or social support services; and 3) To demonstrate the use of a SenseMaker® survey in public health research in a Canadian context. This study contributes Canadian data to a larger international comparative study taking place between 2019 and 2020 in Canada, Mongolia, Thailand and the Democratic Republic of the Congo. A SenseMaker® survey starts with a micro-narrative prompt (and the subsequent capture of an audio recorded or type written story), followed by questions that generate an understanding of the micro-narrative from the participants perspective as well as sociodemographic information. A purposive sample of 106 participants in Kingston, Ontario was recruited through a community-based organization and in open public spaces. The data were analyzed using a modified QUAGOL coding protocol (Dierckx de Casterlé et al., 2012). A conceptual model was produced that was informed by previous theory and the collected qualitative data. Modifications to previous understandings of access were highlighted. This research contributes to our understanding of health care and social service experiences and accessibility among parents across diverse contexts of adversity. Ultimately, this could help inform the work of health and social service providers.

abstract: M.Sc.


title: Developing Synthetic Actin Toxins for the Treatment of Metastatic Cancers

contributor:
Craig, Andrew
Allingham, John
Biomedical and Molecular Sciences

subject:
Cancer Metastasis
Actin Cytoskeleton
Synthetic Analogs
HER2

abstract: Metastasis is the leading cause of cancer related deaths and new therapies that disrupt the metastatic process are urgently needed. The actin cytoskeleton is very dynamic structure required for cancer cell invasion and metastasis but has yet to be targeted effectively. Here, we focus on “actin addiction” of metastatic cancers that reflects their dependence on actin polymerization into filamentous-actin (F-actin) based protrusions to invade and metastasize. Human Epidermal Growth Factor-2 (HER2) is a driver and clinical target in cancers with high rates of metastasis. Despite the improvements in therapies targeting HER2, many tumors develop resistance and still progress to metastatic disease. We predict that F-actin disrupting drugs may complement existing cancer therapies. Here, we tested a series of synthetic analogs of Mycalolide B (Myc B), a marine macrolide toxin that severs F-actin, for their effects on SKOV3 ovarian cancer cells. A lead analog, BVP-02-013, was identified as its increased cytotoxicity caused dose dependent suppression of directional migration and invasion kinetics in SKOV3 cells. Live cell imaging of SKOV3 cells expressing a Life-Act GFP reporter showed that this analog severs cellular F-actin into large aggregates within minutes of treatment at doses in the low µM range. Like Myc B, treatments with BVP-02-013 caused loss of leading-edge protrusions and extracellular matrix degradation by invadopodia in SKOV3 cells. These results imply that synthetic Myc B analogs have potential as novel anti-cancer drugs and will provide a rationale to continue the development of actin toxin-based Antibody Drug Conjugates that will deliver actin severing payloads to complement the cytostatic effects of existing HER2 inhibitors.

abstract: M.Sc.