title: SELF-EXPRESSION, CONCEPTUALIZATION, AND RECREATED EXPERIENCES OF THE EMOTIONAL WELL-BEING OF CHILDREN AND YOUTH WITH SEVERE MOTOR AND COMMUNICATION IMPAIRMENT

contributor:
Fayed, Nora
Davies, Claire
Rehabilitation Science

subject: child

subject: youth

subject: disability

subject: adolescent

subject: emotional well-being

abstract:
Children/youth with severe motor and communication impairment (SMCI) have difficulty communicating through speech, writing with a paper and pencil, or using a standard computer keyboard. Children/youth with SMCI are easily overlooked or misunderstood by unfamiliar people; primarily use a mobility aid; and have difficulty handling objects. Often, their emotional needs, responses, and messages can be missed or overlooked by peers and caregivers who do not know them, creating a profound risk of social isolation. A conceptual basis for studying the emotional wellbeing specific to this group of children/youth is missing from the literature.

This dissertation is focused on advancing the knowledge about emotional well-being for children/youth with SCMI. The dissertation consists of three manuscripts i) a systematic review exploring methods of direct assessment of emotional well-being information from children/youth with SMCI, ii) a conceptualization of emotional well-being specific to children/youth with SMCI, and iii) a qualitative method for “recreating experiences” of individuals whose experiences are difficult to capture by self-report due to profound motor, communication, and/or cognitive impairments.

The research supporting the three manuscripts was undertaken as follows. First, the systematic review was conducted through searches of six academic databases, informed by keywords under the following areas: i) population, ii) assessment methods, and iii) target information. The systematic review identified that children/youth with SMCI rarely use high-technology communication methods to self-express emotional well-being information, and this occurs in limited single contexts. Next, primary guardians of children/youth with SMCI were involved in photo/video data collection. Qualitative interviews were conducted with primary guardians and other familiar people to understand emotional experiences of children/youth. A conceptualization of emotional well-being for children/youth with SMCI was developed consisting of nine themes grouped into four domains. Finally, findings from the qualitative work brought forth a novel method which is described by three axes: i) informants, ii) data collection strategies, and iii) analyses and reflexivity. The “recreated experiences” method was developed to provide a toolkit for disability researchers.

This dissertation emphasized the unique components of emotional well-being for this group and the importance of familiar persons’ knowledge. Findings illustrate the personal characteristics of children/youth with SMCI which can enhance opportunities for meaningful care, social relationships, and involvement in research.

abstract: PhD


title: The Current Use of Human Patient Simulation Manikins in Saudi Arabian Nursing Schools: A Sequential Exploratory Study

contributor:
Tregunno, Deborah
Nursing

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

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

rights: Intellectual Property Guidelines at Queen's University

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

rights: Attribution-NonCommercial-ShareAlike 3.0 United States

subject:
use of simulation
Human Patient Simulation Manikins
Saudi Arabia
Nursing
Learning theory

abstract:
Background. To optimize the use of simulation technology, it is important to understand its educational practices and the theoretical underpinning that currently supports its use. The purpose of this thesis was, therefore, to explore the current use of clinical simulation in undergraduate nursing education in a specific context and to understand the theoretical and pedagogical principals that underpin the use of simulation.
Methods. A scoping review, using the Joanna Briggs Institute (JBI) methodology, was conducted to determine which learning theories are suited for simulation in undergraduate nursing education. A descriptive cross-sectional survey of Saudi Arabian schools of nursing was undertaken to explore the use and types of simulation and the pedagogical principles underpinning their use.
Results. The scoping review results showed that the majority of literature focused on constructivism and experiential learning theory. Findings suggest there is a lack of empirical research on clinical simulations in nursing education that include educational theories. A combination of theories might be applied to frame simulation experiences for optimal effectiveness. It is possible for a variety of learning theories to be applied to the three distinct steps involved in simulations.
The cross-sectional survey responses indicated that faculty members have a growing interest in using simulation and that there are an increasing numbers of nursing schools planning to purchase clinical simulation scenarios and equipment. The survey results pointed to the need for enhancing the pedagogical principle and practices associated with the use of clinical simulation. Lack of adequate staff training and clinical staff numbers, lack of time, lack of support from administrators and technical individuals, and lack of equipment were the main constraints to the use of this technology.
Conclusion. More primary research should be conducted to assess the benefit that students gain when clinical simulation teaching and learning are underpinned by learning theory. Simulation is an evidence-based strategy to facilitate high-quality experiences that foster students’ critical-thinking and clinical-reasoning skills. It is important to focus on the methodology of simulation rather than the technology. Therefore, Saudi Arabian nursing schools should spend time considering how to best use simulation in their curricula to promote student learning.

abstract: PhD


title: The Countess’ Print Album: An Examination of Heads, English & Foreign Collected by Henrietta Louisa Jeffreys, Countess of Pomfret

contributor:
Dickey, Stephanie
Art History

subject:
Print Collection
Eighteenth-Century
Henrietta Louisa Fermor
Henrietta Louisa Jeffreys
Lady Pomfret
Eighteenth-Century Women's History
Printed Portraiture
Eighteenth-Century Rare Book

abstract: In 1730, Henrietta Louisa Fermor (née Jeffreys) compiled an album of printed portraits with hand-written biographies. Through a detailed examination of the portraits and biographies held in the album titled Heads, English & foreign collected by Henrietta Louisa Jeffreys, countess of Pomfret, this thesis places the album in the historical context of 1730s English print collecting. At the time the album was created, print collecting was extremely popular with upper class Europeans, like the countess. Not only does the album reflect the history of collecting prints and biographies, but it also reflects the ways upper-class women engaged in intellectual endeavours during the Enlightenment through socially acceptable means. In an era when intelligent women were met with suspicion and ridicule, women who collected or otherwise cultivated learning had to engage with such practices in a socially accepted way or choose to ignore the criticism. Neither approach shielded a woman completely from gossip. The album will be discussed in the context of the sexism the countess faced and how that sexism shaped her historical legacy.

abstract: M.A.


title: Tensor Decomposition Method Applied to Recommendation Systems

contributor:
Feng, Wenying
Hassanein, Hossam
Computing

subject:
Web service recommendation
Quality of service
Tensor decomposition

abstract: With the growth of network web services, web service recommendations based on the quality of service (QoS) attribute have become a research interest topic. Service recommendation technologies can help users discover new web services and make their online experience better. Further, by providing users with recommendations for high-quality web services, these technologies ultimately benefit both users and service providers. In this thesis, we study the tensor decomposition in web service recommendations. In particular, we propose new tensor computational methods and algorithms for QoS attribute prediction to improve the recommendation accuracy. Our methods follow the machine learning techniques. First, to remedy the shortage of low prediction accuracy rates caused by the lack of initial data samples, a traversal-tensor method (TTM) is proposed to enhance the sampling scheme. The new method integrates the feature factor matrices to construct more data samples for tensor decomposition. We analyze and validate the new algorithm in comparison with the traditional tensor decomposition applied to service recommendations. Empirical studies with multiple datasets show that the TTM effectively improves the prediction performance. Second, a modified regularization term is designed and applied with the TTM to overcome the overfitting problem. This is done by using a linear combination of two commonly applied regularization models. It is shown that the updated term can increase the accuracy rate of predicting QoS attributes and better support the TTM method. Third, a two-step strategy approach involving a K-means clustering with TTM is introduced to deal with the initial unorganized data. The pre-clustered data are used as input to the TTM to complete the QoS attribute prediction. This process is evaluated between our methods and the clustering method. The thesis describes a framework of tensor-based web service recommendation by synthesizing the above methods. This framework is centered on TTM, with a modified regularization term to support TTM and a method to handle the initial unorganized data.

abstract: PhD


title: Let's All Go to the Drive-In: An Audio History of the Drive-In Movie Theatre

contributor: Film and Media (Screen Cultures and Curatorial Studies)

rights: Attribution-NonCommercial-NoDerivs 3.0 United States

subject: drive-in, film, exhibition, history, technology, drive, theatre, theatres, theater, theaters, drive-in theatre, drive-in movie theatre

abstract: This project is a series of podcasts that look at the history of the drive-in movie theatre from its inception, through its heyday and decline, up to its recent and unexpected resurgence. It examines the drive-in’s shifting role in community life and the ways in which outdoor movie screenings have remained a unique and relevant community experience, serving the public in different ways, at different times. The drive-in the brought moviegoing to new audiences in the 1930s, became an all-in-one family night out after the war, provided a place of privacy and independence for midcentury teens and became entrenched in their culture. Drive-ins managed to survive decades of decline and took on a new role during the COVID-19 pandemic. This podcast covers all these topics, the reasons behind them, all while drawing in fun and, hopefully, entertaining stories from the drive-in’s history.

abstract: M.A.


title: Distributed Fibre Optic Sensing to Assess Support Reactions and Behaviour of Composite Steel Bridges

contributor:
Hoult, Neil
Bentz, Evan
Civil Engineering

subject:
Distributed Fibre Optic Sensing
Composite Steel Bridges
Strain
Support Reactions
Structural Health Monitoring
Flexural Stiffness
Composite Behaviour
Damage Detection
Field Monitoring

abstract:
The method proposed in this investigation involves using distributed fibre optic sensing (DFOS) strain measurements to estimate support reactions in beams through an experimental investigation that involved beam, model bridge, and field load tests. Five steel beams were instrumented with fibre optic sensors and loaded in simply supported and continuous beam configurations. Disturbed regions in DFOS strain measurements were found to extend a distance equal to the depth of the section from supports and loading points. An estimate of flexural stiffness was used to calculate support reactions, which were found to be inconsistent with results obtained from load cells. The error between DFOS calculated support reactions and load cell support reactions was then minimized to determine calibrated stiffness values for each beam.
The five slender steel beams were then assembled into a two-span bridge configuration and connected by a series of steel deck plates. Stiffness values determined from the individual beam tests were used to calculate support reactions for each beam at each support. The sum of the support reactions was compared with load cell measurements at the loading points and showed good overall agreement in tests involving consistent loading between beams. Non-linear strain profiles were observed in tests involving concentrated loading in the centre of the bridge, which decreased the accuracy of the DFOS calculated support reactions. DFOS strain derived neutral axis measurements were used to estimate the level of composite action in the bridge and adjust the flexural stiffness of each beam. Part of a girder in a steel beam with concrete deck bridge in Kingston, Ontario, was instrumented with fibre optic sensors and loaded by a truck driving across the bridge deck at a range of speeds. DFOS calculated shears were compared with the results of a numerical analysis to determine that the girder carried approximately 25% of the truck load when the truck was near the instrumented region, compared to 79% of the truck load calculated using live load distribution factors from a design code. Load sharing between girders was found to have a greater effect when the truck was positioned further from the pier.

abstract: M.A.Sc.


title: Optimization of UAV-borne Aeromagnetic Surveying in Mineral Exploration

contributor: Geological Sciences and Geological Engineering

subject:
Aeromagnetics
UAV
Mineral Exploration
UAV-borne Aeromagnetic System
Drone
UAV Electromagnetic Interference
Unmanned Aerial Vehicle
Remotely Piloted Aircraft Systems
RPAS
Near-Surface Geophysics
Geophysics
Magnetometry

abstract: The main objective of this research is to conduct a detailed analysis of the design, integration, and application of unmanned aerial vehicle (UAV) aeromagnetic surveys for improved target characterization in mineral exploration. Specifically, the design and viability of a suspended, semi-rigid magnetometer mounting system integrated on multi-rotor UAVs is investigated. Although a semi-rigid mount offers some technical benefits over other mounting techniques, its practical implementation allowing for the collection of industry standard aeromagnetic data has proven to be quite challenging due to the numerous interrelated optimization factors that can adversely affect either the UAV platforms maneuverability and stabilization, or the magnetometers data quality. To address and characterize these challenges, a general procedure involving empirical lab and field tests was developed to collect and analyse numerous parameters used to assess the performance of the developed UAV-borne aeromagnetic system. Specifically, this involved characterizing the frequency and amplitude of a variety of magnetic interference signals and developing solutions to mitigate adverse effects on the UAV-borne aeromagnetic data quality. Ultimately, the main motivation of this work is to lay the technical foundation demonstrating and establishing UAV-borne aeromagnetic systems as a trusted and viable geophysical surveying technique. Therefore, this research is aimed at describing and bringing to the forefront some of the key issues that affect the achievable resolution and quality of UAV-borne aeromagnetic data, as well as outlining practical solutions, both from a technical and data processing standpoint. Building upon the development, integration, and characterization of the UAV-borne aeromagnetic system, a 3D UAV-borne aeromagnetic survey was conducted over a mineral exploration target to demonstrate the benefits and best practices of employing this innovative form of geophysical surveying compared to the conventional methods of terrestrial and manned aeromagnetic surveying. Overall, the analysis of the critical factors governing the design, integration, and application of UAV-borne aeromagnetic systems presented herein provides valuable insight to be used for the successful deployment and future development of UAV-borne aeromagnetic and electromagnetic systems in mineral exploration applications.

abstract: PhD


title: Dividing the Arctic: Sovereign Rights on Extended Continental Shelves in The High North

contributor:
Lamp, Nicolas
Law

subject:
Arctic
Maritime delimitation
Extended continental shelf
Three-step approach
Sector Theory

abstract:
This thesis examines the delimitation of the continental shelves beyond 200 nautical miles (M) in the Arctic Ocean. It analyzes the regimes of the continental shelf and the Arctic, as well as the rules applicable to the delimitation of the continental shelves, to develop the delimitation scenario for the overlapping entitlements of Canada, Denmark, and Russia. Whereas the scope of the research was narrowed down to the Central Arctic Ocean, the outcomes have implications for the more general issue of the delimitation of the extended continental shelves and demonstrate that the existing delimitation methodology of international tribunals needs to be adjusted in cases that exclusively or primarily concern the ECSs.
Article 83 of the UNCLOS, which regulates the delimitation of the continental shelves, does not provide for a binding method of delimitation. This means that the concerned Arctic States are free to choose any delimitation method they consider suitable. This thesis applies the three-step approach developed by international tribunals because it incorporates the most popular method of maritime delimitation, equidistance. However, the application of the methodology of international tribunals to the case of the Central Arctic Ocean revealed issues that are unique for the ECSs and demand the adjustment of the method for the identification of the relevant coasts and relevant area in delimitation. Differences between the continental shelves within and beyond 200 M make the application of the three-step approach challenging. The argument that this thesis develops is that the distinctions between the two types of the shelves influence the delimitation, and hence, these distinctions should be considered by States and international tribunals when establishing borders between the continental shelves beyond 200 M.
This thesis also considers the interplay between the regimes of the continental shelf and the Arctic and analyzes how the ECSs in the Arctic can be delimited. Whereas this thesis does not provide the ultimate solution for the delimitation of the ECSs in the Central Arctic Ocean, it attempts to analyze what legal and non-legal factors will influence the establishment of the maritime borders between Russia, Denmark, and Canada and suggests a delimitation scenario.

abstract: PhD


title: A Study of the Muon Veto and Cosmogenic Neutron Background for the Scintillating Bubble Chamber Dark Matter Experiment

contributor: Physics, Engineering Physics and Astronomy

subject:
dark matter
direct dark matter detection
low background experiments

abstract: Dark matter is one of the most intriguing and elusive physics topics in recent decades with many dark matter candidates proposed and many experiments designed to search for these candidates. One category of candidates known as low-mass WIMPs is becoming of interest to the dark matter community with numerious experiments attempting to reach very low energy thresholds to search for these particles. The Scintillating Bubble Chamber (SBC) is one such experiment. The SBC is a bubble chamber using a scintillating target fluid allowing it to reach lower energy thresholds than previous bubble chamber experiments. This thesis investigates one major background for the experiment: cosmogenic neutrons, sometimes called muon-induced neutrons. This background can be mitigated using a muon veto consisting of a water shield surrounding the SBC with photomultipler tubes (PMTs) mounted inside to capture muon produced Cerenkov light. The first part of this thesis' research tested various muon veto design and found that adding reflectivity to the inner walls of the water shield is crucial to achieve 99\% veto efficiency. The second part of this thesis' research counted the number of expected bubble events produced by cosmogenic neutrons and found that adding a water shield significantly dropped the number of events from 0.152 events per year to 0.076 events per year. All this work is done using Monto Carlo simulations within the particle physics simulation software Geant4.

abstract: M.Sc.


title: Studying reopened bugs in open source software systems

contributor:
Hassan, Ahmed E
Computing

subject:
bug reports
reopened bugs
data quality
open source
Model interpretation
pre and post-release bugs

abstract:
Reopened bugs can degrade the overall reputation of a software system since such bugs lead to a loss of end-users trust regarding the quality of the software. Thus, understanding the characteristics of bugs that are reopened, and what factors are more likely to affect a reopened bug (especially post-release reopened bug) to be fixed rapidly throughout the release lifecycle, could provide insights in helping software developers to avoid/minimize such bugs.

In this thesis, we study the characteristics of reopened bugs and the factors that lead to a post-release reopened bug being fixed rapidly/slowly. To understand the characteristics of reopened bugs, prior studies built statistical or machine learning models to analyze the factors that impact the likelihood of a bug getting reopened. However, we observe several aspects that require further investigation from prior studies: 1) previously studied datasets are too small (only consisting of 3 projects) 2) 1 out of the 3 studied projects has a data leak issue. 3) the previously used experimental steps are outdated. After considering such aspects, we observe that only 34\% of the studied projects give an acceptable performance with AUC $\geqslant$ 0.7 for predicting if a bug will be reopened. Moreover, we observe that post-release reopened bugs take only 189.1 hours rework time (time taken to resolve a reopened bug) as compared to 388.4 hours for rework time in pre-release reopened bugs. To study the likelihood of a post-release reopened bug getting fixed rapidly, we build prediction pipelines and observe that the models give an acceptable AUC of 0.78 to determine if a post-release reopened bug will get resolved rapidly/slowly. Our model predicts if a post-release reopened bug will get resolved rapidly (i.e., less than 3 minutes) or slowly (i.e., more than 4,538 hours) by considering top 20\% fast resolved bugs as rapidly resolved and bottom 20\% fast resolved bugs as slowly resolved.

Based on our findings, we encourage future research to leverage the rich data available during and after a bug is reopened, to understand the eventual resolution of a reopened bug and we also encourage researchers to consider pre-release and post-release reopened bugs separately in their analysis as studying reopened bugs as a whole leads to biased implications.

abstract: M.Sc.


title: WEAK AXIS BENDING RESPONSE OF POLYGONAL HOLLOW STEEL SECTIONS

subject:
Hollow structural section (HSS)
Polygonal hollow section (PHS)
Weak-axis bending
telescopic boom

abstract:
This thesis consists of two sections: the first section evaluates the structural behaviour of hollow structural sections (HSS) including polygonal hollow sections (PHS) and rectangular hollow sections (RHS) under weak-axis four-point loading, and the second section focuses on the complementary structural evaluation of PHS and RHS beams via distributed fiber optic strain sensors (DFOS). The moment capacity of the RHS tested were determined to be higher than that of their companion PHS: 32% higher for an RHS305×203×6.4 versus a PHS305×203×6.4 and 40% higher for an RHS356×254×6.4 versus a PHS356×254×6.4. Local buckling on the compression flange/upper part of the web was observed to be the primary failure mode for all beams. Vertical crushing was observed to be more extensive on PHS beams than on RHS beams due to the flattening and folding of the diagonal corners of the PHS beams.
The performance of DFOS was evaluated for thin-walled hollow steel sections under bending and it was determined that it can effectively to identify stress concentrations at loading points and to monitor the evolution of local buckling and other failure modes. The integration of strains from DFOS can be used to calculate beam deflections within the linear elastic response range of a thin-walled beam with the accuracy of these calculation results depending on the coverage of beam along its length. The calculated deflections were observed to be 15-20% lower than deflections measured from conventional linear potentiometers for RHS beams with the optical fibers covering 90% of the beam length; whereas the calculated deflections were seen to be 20-30% lower for PHS beams with a fiber coverage of 82-87% of the beam length.

abstract: M.A.Sc.


title: A Feminist Ethnography of Indoor and Outdoor Sport Climbing and Bouldering

contributor:
Adams, Mary Louise
Kinesiology and Health Studies

subject:
rock climbing
gender
embodiment
feminism
settler colonialism
space
discourse

abstract:
As a sport and form of consumption, rock climbing is flourishing. Increasing numbers of people are strapping on rubber shoes and heading to indoor or outdoor spaces to climb. The 2019 State of Climbing Report published by the American Alpine Club (AAC) confirms climbing’s popularity: 4.4 percent of all Americans now climb indoors, whereas a decade ago they were not tracking this statistic. More women are taking up the sport; they make up about half of all indoor climbers (AAC, 2019). Women want to go out and feel empowered in their climbing pursuits, yet they must negotiate implicit and explicit forms of discrimination.
My project centres on one recreational climbing community in southeastern Ontario. I qualitatively explore women’s climbing. My method is feminist ethnography: I interviewed 34 women, collected participant observations over two years, and augmented these materials with personal stories. I subjected all of the research materials to a discourse analysis. My analyses have focused on how gender discrimination intersects with other power relations, including race, class, sexuality, ability and colonialism. I have explored how these intersections organize the participants’ climbing styles and sense of entitlement to space, and I have examined how women’s outdoor climbing can be a form of colonial practice. I develop the argument that, although climbing is a site for discriminatory slights and ideas that naturalize gender differences, participants also actively resist these slights and interrupt traditional femininities and masculinities. Furthermore, I suggest that the misogyny I found at the cliffs cannot be divorced from the settler state; climbing, and outdoor recreation in general, function within a colonial structure and this colonial structure is expressed in gendered ways. It is my hope that this work contributes to the project of addressing historical and contemporary injustices in order to construct a better future that accommodates all people and attends to complex histories of conflict, displacement, and cultural loss in the outdoors.

abstract: PhD


title: Nutrient and Stress-Induced Mitochondrial Hyperfusion Regulates Cell Death Pathways

contributor:
Chan, Edmond
Abraham, Sheela
Biomedical and Molecular Sciences

subject:
Mitochondrial biology
Biochemistry
Amino acid metabolism

abstract: Mitochondria undergo constant cycles of remodelling to sustain normal cell function. As the major cellular metabolic hub, mitochondria are understood to require a precise balance of membrane fission and fusion to maintain mitochondrial genome integrity and levels of oxidative phosphorylation. Mitochondria have been shown to shift the balance of these two opposing pathways to drive a hyperfusion response following proteostasis stress conditions to avoid apoptosis. Importantly, in response to amino acid starvation, mitochondria have been reported to undergo fusion to form elongated structures that avoid degradation via mitophagy. Here, we aimed to study the signals controlling nutrient-dependent mitochondrial fusion and we attempted to reverse the elongation by supplementing three regulatory amino acids, glutamine, leucine, and arginine. Surprisingly, the addback of amino acids did not reverse the elongation, rather, led to stronger mitochondrial hyperfusion. The mechanisms regulating amino-acid dependent mitochondrial hyperfusion response were unknown. We confirmed that addback of amino acids led to metabolic reprogramming that upregulated nucleotide biosynthesis pathways, independent of mTORC1. Additionally, we found the loss of fumarate hydratase prevented amino acid induced mitochondrial hyperfusion, which suggested that amino acid metabolism via the TCA cycle mediates the mitochondrial hyperfusion response. Furthermore, enzymatic inhibition of inosine monophosphate dehydrogenase further blocked this hyperfusion response, indicating a key role of purine biosynthesis in mitochondrial remodelling. The functional role of mitochondrial hyperfusion has been linked to a pro-survival response and we also observed a similar suppression of programmed cell death upon amino acid-induced mitochondrial hyperfusion.  These results suggest a novel metabolic mechanism is responsible for sensing cellular amino acids to regulate mitochondrial fusion and cell survival.

abstract: M.Sc.


title: Integrated Topology and Packaging Optimization Using the Component-Existence Model

contributor:
Kim, Il Yong
Mechanical and Materials Engineering

subject:
Topology Optimization
Packaging Optimization
Layout Optimization
Multi-Component

abstract:
Driven by the demand for safer and more sustainable transportation, the automotive industry is experiencing a significant shift away from conventional vehicle architectures toward all-electric mobility platforms. Core to the engineering development and performance of these new models is lightweight systems design to explore the dynamic interaction between underlying structures and modular vehicle components. At the conceptual level, these interactions can be described in terms of both material and component distribution problems. Here, state-of-the-art numerical design methods like topology optimization (TO) can be used to develop the optimum material distribution for vehicle structures considering mechanical responses like stiffness and mass. Similarly, numerical techniques for packaging optimization (PO) can be used to obtain the optimum configuration of vehicle components considering system properties such as packing efficiency and center of mass. New methods for integrated topology and packaging optimization (iTOPO) are enhancing these individual workflows, seeking to couple the two traditionally standalone problem statements into a holistic design process. Through the coordinated treatment of material and component distribution variables, iTOPO methods are posed to unlock significant design freedom in conventional engineering models to ultimately drive high-impact and non-intuitive insights within clean-slate optimization.

To advance the field beyond the current methods, this thesis introduces a novel approach for iTOPO. Presented as the component-existence model, this method applies a new class of packaging design variable within the material distribution problem to enable a unified density-based approach. In this work the core theory and implementation build upon a standard TO workflow through the development of new concepts in design fields, mapping functions, and problem statement formulation, while adopting robust techniques for numerical analysis and non-linear programming to drive the solution process. The resulting methodology overcomes key practical and numerical challenges seen in conventional approaches and offers a flexible and scalable iTOPO implementation demonstrated in various examples. This culminates in three automotive case studies to demonstrate the effectiveness of the overall methodology as a practical design tool.

abstract: PhD


title: Hyperspectral Imaging Simulator and Applications for Unmanned Aerial Vehicles

subject:
Hyperspectral Imaging
UAVs
Simulator
Remote Sensing

abstract: Mineral exploration utilizing hyperspectral imaging sensors aboard low-altitude airborne platforms is still a relatively new and developing research topic. The main reason is the difficulty of finding the optimal combination of platform, sensor, and survey design for specific targets in various geological settings. This research firstly aims to examine the reliability of an industry-standard workflow for hyperspectral imaging using an unmanned aerial vehicle (UAV) for a mineral exploration target in Cuprite, Nevada. A versatile hyperspectral imaging (HSI) simulator called HYSIMU has been developed that can be used to simulate different scenarios based on customizable flight and target parameters. Random mineral reflectance spectra are assigned to synthetic digital elevation models (DEMs) and several flight scenarios are simulated on those DEMs using different sensors and selectable survey parameters such as altitude, speed, and sun position with options to add spatial noise, spectral noise, and terrain shadow effects. The synthetic hyperspectral data generated from each scenario are further processed using the workflow established earlier in this research to determine the target minerals and to create classification maps. In this study, three ground truth scenarios with different levels of complexity were simulated with varying survey parameters such as altitude (10 to 200 meters), velocity (1 to 100 m/s), and sun elevation (0°, 45°, and 90°). A sensitivity study is performed using four metrics to compare the ground truth data and the obtained classification maps. The results showed that HYSIMU has great potential as a tool to optimize hyperspectral imaging in mineral explorations by finding the right combinations of flight parameters, primarily the altitude and flight speed which affect the survey time and total cost. There are opportunities for further development of HYSIMU to make it more versatile. It was also implemented to test the detectability of agricultural targets in different soil conditions. Lastly, the use of satellite-based Land Surface Temperature (LST) as an earthquake precursor is examined and its potential to be combined with hyperspectral imaging is discussed.

abstract: M.A.Sc.


title: Is Service Provision Always Equitable? Analyzing Access to Dental Services and Oral Health of Older Adults in Ontario

contributor:
Rosenberg, Mark
Geography and Planning

subject:
Health Geography
Oral Health
Access to Health Services

abstract:
The provision of dental services within the Canadian and Ontario healthcare systems is unique, as the majority of dental services are privately delivered. Many vulnerable populations, including older adults, have difficulty accessing dental services because of their private nature, leading to negative oral health outcomes and barriers in accessing dental services.

The purpose of this thesis was to explore the oral health outcomes and barriers in accessing dental services among older adults (65+) in Ontario. Following the distribution of an online questionnaire, IBM SPSS 26.0 was used to perform crosstabulations, chi-square tests, and multivariate logistic regression models. The results of the quantitative analysis unveiled relationships between oral health outcomes and barriers in access, with numerous social determinants of health.

The oral health outcomes reported were incidences of poor self-rated oral health, tooth removal by a dentist due to decay or gum disease, a lack of having one or more teeth, the use of dentures, having toothaches in the past month, and pain in and around the jaw joints. Respondents who suffered from poor overall health outcomes, or issues pertaining to income and access to insurance were more likely to experience negative oral health outcomes. The barriers in accessing dental services included location within a respondent’s community, proximity to the dentist, the respondent’s relationship with the dentist and staff, the affordability of dental expenses, and the impact of cost on access to dental services. Location and one’s relationship with space and place, and the presence of social support, income, and access to insurance were influential to the types of impacts these barriers created.

This research indicates that there is a need for the provincial and federal governments to acknowledge the gaps present surrounding the provision of dental services in the healthcare system. There must be reflection on the usefulness of the current system, as well as change to mitigate the barriers currently in place. Future research can facilitate this change by continuing to analyze the geographic barriers on a narrower and more localized scope, and researching barriers involving other vulnerable populations.

abstract: M.A.


title: The Value of Musical Interactions in Early Development in Down syndrome: A Grounded Theory Study

contributor:
Levine-Rasky, Cynthia
Education

rights: Attribution-ShareAlike 3.0 United States

subject:
Down syndrome
oral language development
early childhood
music
early intervention

abstract: This study examines musical interactions in the early life of a child with Down syndrome (DS) who developed fluent oral language skills by the age of five. This allowed for rich social and learning experiences in kindergarten and set a solid foundation of early literacy skills. Research in young children with DS has mainly focused on improving parent-child communication, but interventions require unfeasible levels of frequency to be highly effective. Current research on the benefits of music for typically developing children indicates improvements to auditory abilities, vocabulary, oral language skills, attention, emotional regulation and prosocial skills. No such studies have yet to be conducted with children who have DS. The neurocognitivist approach to language suggests that wider elements of development are connected to language development, and this is another area in need of further research. This study begins to address these gaps by analyzing several different sources of personal data from the early life of a child with DS. These include autoethnographic writing by the mother, personal mementos such as photographs, a compact disc (CD) collection, social media posts and the child’s early years’ developmental reports. Grounded theory was used to analyze the influence of musical experiences and song on the extraordinary development of this child with DS. Results lay the foundation for wider research projects and have implications for early childhood intervention and education practice, public policy, and parent training for families with children who have DS and possibly other developmental challenges.

abstract: M.Ed.


title: Building Foundations for Research on Self-Management for Chronic Low Back Pain in Ethiopia

contributor:
Miller, Jordan
Donnelly, Catherine
Rehabilitation Science

subject: Chronic low back pain

subject: Self-management

subject: Self-management supports

subject: Roland Morris Disability Questionnaire

subject: Pain Self-efficacy Questionnaire

subject: Psychometric tests

subject: Interpretative Phenomenological Analysis

subject: Interpretive Description

subject: Ethiopia

abstract:
Low back pain is a major musculoskeletal health problem globally. People with chronic low back pain have unpredictable recovery trajectories and poor prognoses. They also experience persistent or recurrent disability compared to people with acute low back pain. Self-management supports are regarded as effective management for people with chronic low back pain. However, there are gaps related to research on chronic low back pain self-management in Ethiopia. This thesis has four studies with an overarching aim of building foundations for research on self-management supports for people with chronic low back pain in Ethiopia.
The first study was an interpretative phenomenological study aimed at exploring the lived experience of adults with chronic low back pain in Ethiopia. The findings suggested that chronic low back pain impacted the lives of people with the condition in a multitude of ways. The findings also provided insight into how people with chronic low back pain manage, cope, and live with pain.
The second study explored health care providers’ understanding and perspectives related to self-management and how they facilitate self-management support for people with chronic low back pain in Ethiopia. The findings indicated that self-management is a new concept in Ethiopia. The health care providers conceptualized self-management support which did not align with existing literature on best practices in self-management for people with chronic low back pain.
The third and fourth studies fill the existing gap of the absence of outcome tools used in implementing and evaluating chronic low back pain self-management in Ethiopia. The third study aimed to cross-culturally translate and adapt the Roland Morris Disability Questionnaire iii into Amharic and validate it among people with low back pain in Ethiopia. The results suggested that the Amharic version of the Roland Morris Disability Questionnaire is a reliable and valid outcome measure among Amharic-speaking Ethiopians with chronic low back pain. The last study cross-culturally translated, adapted, and tested the psychometric properties of Self-efficacy Questionnaire in Ethiopia. The results suggested that the Amharic version of the Pain Self-efficacy Questionnaire is a reliable and valid outcome measure among people with chronic low back pain in Ethiopia.

abstract: PhD


title: To Protect or To Punish: Illuminating Pathways from Care to Criminalization

contributor:
Myers, Nicole
Sociology

subject:
Bail / Judicial Interim Release
Child Welfare
Criminal Justice
"Crossover" Youth
'Aging Out' of Child Welfare

abstract:
This dissertation undertakes an in-depth analysis of the compounding effects of the child welfare and criminal justice systems on young adults (ages 18 to 24) in Ontario. The research is informed by qualitative, critical race methodologies, including semi-structured interviews with 25 young adults who have been involved in both systems; 10 practicing lawyers in Ontario; and 10 Youth- in-Transition Workers. The analysis and findings are presented in two academic papers and one public policy report.
The first manuscript uses an intersectional framework to uncover reasons why racialized children and youth are overrepresented in the child welfare and criminal justice systems; findings reveal race-based differences exist in the treatment of accused individuals who have been in care and experience mental illness in the early stages of the legal process, from arrest to bail. The second manuscript explores understandings of risk in bail courts and uncovers ways this concept functions as an organizing principal. This analysis illustrates how care status comes to be identified as a risk factor. Together these manuscripts demonstrate ways that risk-thinking fails to account for the particular conditions, circumstances, and contexts of youth leaving care, to youths’ disadvantage. The third manuscript is a public policy report that addresses gaps in public knowledge by synthesizing existing information about the adverse outcomes experienced by youth leaving care in five areas: education; employment, poverty, and income support; housing and homelessness; criminalization; and mental and physical health and wellbeing. Using this information, recommendations focus on ways to disrupt pathways from care to criminalization. As a complete work, this dissertation analyzes ways that race impacts the experiences of youth leaving care in the criminal justice system, examines understandings of risk in bail courts, and highlights pathways from care to criminalization.

abstract: PhD


title: Improving Teaching Practice Through the Cross-Disciplinary Pairing Of Mathematics And Music

contributor:
Pyper, Jamie
Education

subject: Music Mathematics Cross-Disciplinary Interdisciplinary

abstract: For a variety of reasons, there are many high school aged students who underachieve in their mathematics studies. There is some research that suggests that low mathematics motivation and self-efficacy could be responsible for part of this underachievement, and other research that found that combining mathematics with music in a cross-disciplinary style improved mathematics motivation and self-efficacy in their participants. The goal of this research was to further explore cross-disciplinary pedagogical approaches and to understand the experience of participants as they learned mathematics concepts through the framework of musical instrument design and construction. Through this understanding it was also my goal to improve my teaching practices, and to better facilitate this goal I chose Action Research as my methodology for its focus on professional development and finding solutions to everyday problems. This research found that there are some benefits to participants’ feelings of motivation, competence, and confidence for mathematics when placed in this musical framework and that there are many ways in which the teacher was able to improve their teaching practices through designing and executing these cross-disciplinary lessons.

abstract: M.Ed.


title: HYDRAULIC PERFORMANCE OF GEOSYNTHETIC LINERS IN TAILINGS STORAGE FACILITIES

contributor:
Rowe, Kerry
Civil Engineering

subject: Geosynthetics Geomembrane Leakage Tailings Piping Hole

abstract:
Experiments are conducted to investigate the impact of fines content on the compressibility and permeability of the cyclone tailings, and to quantify leakage through a GMB hole overlain by saturated tailings. The effect of hole shapes, hole sizes, GMB thicknesses, tailings thicknesses, tailings homogeneity, applied stresses, water heads, subgrade grain-size distributions and surface irregularity, and a geotextile filtration layer on leakage and piping through the GMB defect are evaluated.
It is shown that increasing the fines content from 0 to 100%, the involvement of the fine and coarse components of soil skeleton can be classified into four categories: no fines involvement, fines partially involved, increasing cushioning effect surrounding the coarse, and constant cushioning effect.
For leakage through a circular GMB hole, a 1.9- and 5.0-fold increase in hole diameter cause a 1.8- and 6-fold increase in leakage, respectively, whereas a 2-fold increase in GMB thickness results in an 10% decrease in leakage. With the filter incompatible subgrade, a 2- to 4.5-fold higher leakage arising from piping is prone to occur at small consolidation stress or with a larger hole. The extent of tailings erosion into the subgrade depends on the filter compatibility and surface regularity of the subgrade, which could be significantly improved by increasing its fine particle component or placing a nonwoven needle-punched geotextile beneath the GMB.
Changing the hole shape from circular to noncircular increases the leakage. There is no significant variation among leakage through triangular, diamond, and square holes, whereas the maximum increment is observed for the rectangular hole. With a constant rectangular length of 100 mm and increasing the rectangular width from 1.7 to 40 mm, the magnitude of leakage increment arising from the noncircular hole shape drops from 2-fold to 1.1-fold.
The percent of head loss within the hole is independent of loading condition and only depends on the hole geometry (i.e., shape and size) and GMB thickness. A simple empirical equation predicting leakage through a circular GMB hole, considering the localized concentration of head loss around the hole and the consequent heterogeneity in hydraulic conductivity due to seepage force, is proposed and validated.

abstract: PhD


title: Classifying and Understanding Cancer Through microRNA-Based Deep Learning

contributor:
Mousavi, Parvin
Renwick, Neil
Computing

subject:
Deep Learning
microRNA
Cancer Classification

abstract:
Accurate cancer classification is essential for improved mechanistic understanding, prognostication, and treatment selection. Advances in next-generation sequencing have allowed large molecular datasets to be acquired rapidly. These datasets can be used to increase our understanding of disease through careful extraction and interpretation of molecular information. microRNAs (miRNAs) are small RNA molecules that negatively regulate gene expression, and their dyresgulation is a common disease mechanism in many cancers. While a number of mRNA and protein biomarkers have been suggested for certain cancers, there has been little translation of miRNA biomarkers to a clinical setting. Through a clearer understanding of miRNA dysregulation in cancer, improved mechanistic knowledge and better treatments can be sought. However, there is currently a paucity of computational methods that can handle large next-generation sequencing data for improved cancer classification and understanding.

In this work, we present three distinct deep learning architectures designed to classify cancer and extract meaningful information from miRNA profiles: a Deep Cancer Classifier (DCC), Deep Neural Map (DNM), and Graph Transformer Network (GTN). First, we use the DCC to classify neoplastic from non-neoplastic tissue from the same origin. The DCC is compared to machine learning and feature selection algorithms to demonstrate the advantages of miRNA-based deep learning. We also identify miRNA cancer biomarkers with distinct differences in neoplastic and non-neoplastic tissue through our feature selection algorithm (e.g., miR-375 in breast cancer). Next, this work is extended to unsupervised classification with the DNM, using only similarities between miRNA profiles to stratify cancer by neoplasticity status and tissue-of-origin. Activation gradients are implemented to determine miRNA biomarkers and interpret sample misclassifications, finding clusters of cancer subtypes and potential higher-grade tumours. Finally, the GTN is employed to analyze the targeting relationship between miRNA and messenger RNAs (mRNAs). The attention of the network determines both miRNA and mRNA biomarkers, as well as important targeting pathways in cancer. We show the importance of analyzing molecular data through deep learning by achieving high classification accuracy, and identifying both well-known and novel biomarkers.

abstract: M.Sc.


title: Controls on terrestrial carbon and nutrient cycling in Arctic permafrost environments

contributor:
Treitz, Paul
Scott, Neal
Geography and Planning

subject:
Nitrogen
Carbon dioxide
Methane
Nitrous oxide
High Arctic

abstract: High latitude regions are being disproportionately affected by changes induced by climate warming. The direction of global environmental change will largely depend on the response of Arctic ecosystems to positive and negative feedbacks, which has implications for the global climate system and the people that inhabit the Arctic region. Improving our understanding of the biogeochemical cycles that influence Arctic terrestrial systems will help improve models predicting future changes in northern latitudes. This research aims to determine the environmental controls on nutrient status and greenhouse gas exchange by assessing the relationships between environmental conditions, soil nitrogen availability, and greenhouse gas exchange under ambient and experimental conditions. At the Cape Bounty Arctic Watershed Observatory on Melville Island, Nunavut, varying land cover types exist across a naturally occurring moisture gradient, allowing us to investigate these relationships in wet and mesic tundra. Soil moisture, as opposed to soil temperature, was the main driver of inorganic nitrogen availability; ammonium was dominant under wetter conditions, while nitrate prevailed in drier conditions. In the wet tundra, soil moisture and ammonium availability together played an important role in mediating the carbon dioxide balance of the wet sedge meadow and ultimately contributed to the wetland being a net carbon dioxide sink across all three study years. While moisture and ammonium availability also played an important role in methane release, with drier conditions favouring nitrous oxide release via nitrifier denitrification, the strong carbon dioxide uptake offset the methane and nitrous oxide release, allowing the wetland to be a net greenhouse gas sink. The experimentally warmed mesic tundra site demonstrated a sustained warming effect on ammonium availability and ecosystem respiration 10-years after experiment establishment, and these effects were mediated by moisture. An enhanced snowfall and warming interaction increased nitrate availability, which corresponded with higher rates of N2O release. Temperature is often thought to be the key driver of changes in high latitude processes, but this dissertation finds that the future greenhouse gas balance of High Arctic systems will largely depend on the response of soil moisture and subsequent nitrogen availability to climate change.

abstract: PhD


title: DETONATION PROPAGATION IN A ROTATING DETONATION ENGINE ANALOGUE WITH NONPREMIXED FUEL-OXYGEN INJECTION

contributor:
Ciccarelli, Gabriel
Mechanical and Materials Engineering

subject:
Detonation
Rotating Detonation Engine
Gravity Current
Gravity Wave
RDE
Diffuse Layer Detonation
Rotating Detonation Engine Analogue
RDE Analogue

abstract:
In industrial explosions, the combustible mixture often accumulates on a ceiling, or forms on the ground. An investigation into detonation propagation through a combustible gas layer in a narrow channel bounded by an inert gas was undertaken using schlieren video and the soot foil technique to obtain the detonation cell structure. A gas layer was generated as a premixed hydrogen-oxygen-nitrogen gravity current over an inert gas, or by injecting hydrogen and oxygen separately into the inert gas from a plenum located at the top of the channel. Both argon and nitrogen were used as the inert gas. For the gravity driven layer tests, the layer development time was varied to control the diffusion of the inert gas into the layer. For times of 1.5 s and less, the detonation propagated through most of the layer at the local argon-diluted theoretical detonation velocity; where a CFD simulation carried out by a lab colleague predicted the argon distribution. For longer times, where significant dilution occurred at the leading edge of the gravity wave, the detonation failed before the end of the layer. Detonations through a layer of reduced reactivity were unstable, with progressively earlier premature detonation failure characterized by decoupling and reinitiation. Nitrogen was shown to affect the detonation propagation more than argon, as it produced a critical propagation distance corresponding to 1.5 s, above which time the detonation did not propagate any further. A detonation failure criterion based on the calculated induction zone length was found to predict the extent of detonation propagation recorded on the soot foil records and was especially accurate along the bottom diffuse interface of the layer.
The jet layer tests successfully produced a detonation propagating through the entire layer. Based on the “chugging” of the detonation front, and the nonuniform, patchy appearance of the cell structure, it was demonstrated that there was a significant mixing issue, with detonable gas pockets formed leading to unsteady propagation. Asymmetry in the soot foil records from the two sides of the channel demonstrated that the high momentum oxygen jets dominated the hydrogen jets, such that most of the combustible mixture ended up on the hydrogen plenum-side window.

abstract: M.A.Sc.


title: Ma(r)king Space, Selling Place: Afro-Caribbean Women’s Spatial Negotiations at Caribana

contributor:
McKittrick, Katherine
Gender Studies

subject:
Caribana
Afro-Caribbean women
Multiculturalism
Citizenship
Belonging
Sexual praxis
Liberation
Freedom
Caribbean culture
Black Geographies
Race
Canada
Poetics of Moving
Dance
Fence
Resistance
Carnival
Blackness
Performance
Toronto's Caribbean Carnival
Diaspora
Wining on anything
Toronto, Ontario

abstract: This MA thesis explores the gendered geographies of Caribana, Toronto’s carnival-festival that celebrates Caribbean dance, music, band competitions, and masquerades/Mas. A longstanding feature of the festival has been the fence along the parade route, which separates the performers from the audience; the fence, which is meant to maintain security and order within the parade, has come to define the geography of Caribana since 2009 (Baute, 2009; News Staff, 2009; Aveling, 2009; Elder, 2016; Otchere, 2017). A prominent logistical feature within the parade, and an entry point into this thesis, I read the fence as a metaphor that interrupts “Canadian” consciousness and illustrates material and ideological representations of the nation’s multiculturalism policy. Specifically, I assert that the Multiculturalism Act codifies racial and cultural difference through its diversity rhetoric and, in turn, normalizes whiteness as an indicator of “proper” citizenship. Thinking about this process alongside the spatial politics of Caribana, the fence, then, unfolds into a material, rather than simply metaphoric site that divides the population according to racial, gendered, and sexualized markers. Afro-Caribbean women are particularly vulnerable to and implicated within these violent processes of place-making as they visibly dominate the parade. The thesis works with interdisciplinary scholarship, creative texts, and original accounts (semi-structured interviews and a survey questionnaire) to explore: how Afro-Caribbean women articulate a sense of belonging that disrupts the normalized construction of Canadian citizenship; how the spatial politics of Caribana are predicated on the maintenance and subversion of white settler nationalism—specifically within official multiculturalism and other policies that promote diversity; and how Caribana illuminates Black spatial negotiations and Black women’s liberatory geographies. This research complicates the multicultural nation by demonstrating the ways that Afro-Caribbean women’s relationship to Canada is contingent on their own creative imaginings of a “deterritorialized citizenship” (Walcott, 2001).  Whether outside of, against, or next to “Canadianness,” Afro-Caribbean women’s sense of place is always in conversation with longer collective histories of Black and Caribbean movement, migration, and diaspora, whereby their struggles for liberation and freedom are always in motion.

abstract: M.A.


title: The Experiences and Understandings of Environmental, Outdoor, and Experiential Educators: A Narrative Inquiry Approach

contributor:
MacEachren, Elizabeth
Education

subject:
Narrative
Outdoor Education
Environmental Education
Experiential Education
Place-Based Education
Qualitative
Narrative Inquiry

abstract: The purpose of this study was to explore the experiences of an exceptional subset of environmental, outdoor, and experiential educators. This study sought to understand how and why their experiences were most significant for their understanding and relationships with nature and led to their lifelong commitment and development of a career in the field of environmental, outdoor, and experiential education. Participants of this study consisted of environmental, outdoor, and experiential educators within Canada. Data was collected through two sixty to ninety-minute semi-structured interviews. The data was analyzed using an inductive process according to the narrative analysis and analysis of narrative approach outlined by Polkinghorne (1995). A deductive approach was also used to apply the place-based education design principles (Sobel, 2008) to the study findings. The participant narratives have been re-storied to emphasize their experiences and perspectives that align with the overall study intent. Themes pertaining to each narrative have been identified, and represent the expressions, understanding and memories of participants in relation to the research questions. In the discussion section, key findings that emerged across all participant narratives are detailed in connection to the research questions, literature, and place-based education design principles (Sobel, 2008). There are implications and considerations for educators from this study, and this research adds to scholarship in the field of environmental, outdoor, and experiential education through the stories of seven exceptional educators.

abstract: M.Ed.


title: The role of Cadherin/Rac1/gp130/Stat3 in neoplastic transformation mediated by activated Src

contributor:
Raptis, Leda
Pathology and Molecular Medicine

subject: Cadherin-11

subject: Stat3

subject: Rac1

subject: gp130

subject: Src

abstract: Results from Dr. Raptis lab previously demonstrated that engagement of cadherins, cell to cell adhesion molecules (E-, N- cadherin or cadherin-11), triggers a significant increase in levels and activity of the Rac/Cdc42 small GTPases. This is followed by secretion of IL6 family cytokines and activation of their common receptor gp130 in an autocrine manner, resulting in phosphorylation of the Signal Transducer and Activator of Transcription-3 (Stat3) on tyrosine-705. Stat3-ptyr705 then dimerizes, migrates to the nucleus and activates transcription of genes involved in cell division and survival. In this thesis, I demonstrate that mutationally activated Src527F also increases Rac1 levels in mouse Balb/c3T3 fibroblasts, leading to secretion of IL6 family cytokines and gp130 activation, triggering a Stat3-ptyr705 increase. Interestingly, our results also demonstrate that cadherin-11 is required, to preserve gp130 levels for IL6 cytokine family signalling. At the same time however, activated Src527F downregulates cadherin-11 levels, in a quantitative manner.  That is, expressed to high levels, Src527F eliminates cadherin-11, hence gp130 signaling and Stat3-ptyr705, while Src527F expression to intermediate levels allows sufficient cadherin-11, hence gp130 levels for Stat3 activation. Taken together, these data establish a loop between Src, cadherin-11, gp130 and Stat3 activation, which reveals the importance of a fine balance between Src527F and cadherin-11 levels in Stat3 activation, leading to cellular survival. Cadherins are therefore emerging as potent Stat3 activators not only in their own right but also as mediators of Stat3 activation by oncogenes such as Src, a finding which could also have significant therapeutic implications.

abstract: M.Sc.


title: Rapid cold hardening and stress-induced spreading depolarization in the central nervous system of Locusta migratoria

contributor:
Robertson, R. Mel
Biology

subject:
Locust
Insect
Rapid cold hardening
Spreading depolarization
RCH
SD
Chill coma
Anoxic coma
CNS
Potassium
Stress
Octopamine
DC potential

abstract: Rapid cold hardening (RCH) is a short-term hormesis in which brief chilling (minutes to hours) significantly enhances the stress tolerance of an animal. Insects live in varied habitats and thus experience different kinds of environmental stresses. To thrive, insects enter a reversible coma, or hypo-energetic state when they are under stress. This is associated with a sudden loss of ion homeostasis and temporary shutdown in the central nervous system (CNS), which is a hallmark of spreading depolarization (SD). Insect stress tolerance is dependent on the sensitivity of their nervous systems to unfavourable conditions, which can be modulated by RCH. In my thesis, I used pharmacological and electrophysiological approaches to investigate the mechanism of RCH and its effect on stress-induced SD in locusts, Locusta migratoria. I show that RCH delays the onset of both chill- and anoxia-induced SD. Octopamine (OA) is an insect stress hormone and I show that OA mimics, whereas epinastine (EP; octopamine receptor antagonist) blocks, the effect of RCH on chill coma (intact locust) and anoxia-induced SD (semi-intact preparation). Additionally, I show that RCH affects the K+ sensitivity of the locust blood brain barrier (BBB) similarly to the previously described effects of OA. Thus, I conclude that OA mediates the RCH-induced delay of the onset of anoxia-induced locust coma at least partially by modulating the K+ sensitivity of the BBB. Lastly, I investigated whether RCH affects anoxia-induced SD via one or more of the following homeostatic mechanisms that are involved in maintaining K+ gradients: Na+/K+-ATPase (NKA), Na+/K+/2Cl- co-transporter (NKCC), and voltage-gated K+ (Kv) channels. I show that NKA and Kv channels (excluding the Shaker family) are involved in SD occurrence and possibly take part in the mechanism of RCH, whereas NKCC is directly involved in the mechanism of RCH. These findings suggest that RCH regulates NKA, NKCC, and Kv channels through an octopaminergic pathway to modulate stress-induced SD in locusts.

abstract: PhD


title: Epicontinental ironstone accumulation during the end-Ordovician glaciation and extinction events

contributor: Geological Sciences and Geological Engineering

subject:
Ordovician
Biogeochemical cycling
Ironstone
Paleoceanography
Glaciation
Mass extinction

abstract:
The Upper Ordovician Neda Formation, Midwest, USA, is composed of hematitic
dolostone and ironstone that rest conformably on crinoid and bryozoan wackestone to packstone
of the underlying Maquoketa Formation. Deposition occurred within the Maquoketa Sea south of
the Transcontinental Arch between 15 and 20°S. Where not eroded, the top of the Neda
Formation is a subaerial laterite that formed as sea-level fell during the Hirnantian Glaciation.
This unconformity is the Ordovician-Silurian boundary and records a regression of at least 100 m
and nearly two million years of exposure.

Lithofacies associations indicate deposition began on a storm-dominated ramp during a
minor transgression, that through coastal upwelling emplaced an anoxic water mass, shutting
down carbonate production. Upwelling of ferruginous and euxinic bottom waters derived from
the Iapetus Ocean produced depauperate, Fe-rich mudstone and granular ironstone. Mixing with
oxygenated surface water is interpreted to have precipitated Fe-(oxyhydr)oxide in the water
column that accumulated as Fe-rich mud on the seafloor. In shallower environments, advection
of Fe away from the upwelling front and Fe-redox pumping beneath the sediment-water interface
produced granular ironstone. Granular ironstone is composed of abundant coated Fe grains
preserving both concentric, redox-aggraded cortical layers and those that are erosively truncated,
which record periods of exhumation, reworking, and reburial beneath the seafloor into the zone
of authigenic precipitation.

It is becoming clear that sedimentologic and geochemical data suggest that Paleozoic
ironstones are the product of upwelling ferruginous water masses rather than Fe derived from
continental weathering. An increase in the equator-to-pole temperature gradient and concomitant
reorganization of thermohaline circulation during Hirnantian Glaciation likely intensified coastal
upwelling and drew ferruginous seawater into the Maquoketa Sea to produce ironstone. Such
expansion of anoxic conditions supports recent research suggesting the onset of shallow anoxia
in other basins contributed to the second pulse of the end-Ordovician mass extinction.
Widespread anoxia probably persisted into the early Silurian.

abstract: M.Sc.


title: Abolitionist Intimacies

contributor:
Guenther, Lisa
Cultural Studies

subject:
abolition
prison studies
decolonial studies
anti-Blackness
Black feminism
Black resistance
Arts-based scholarship

abstract:
Abolitionist Intimacies is a work in three parts that addresses scholarly, creative, and community dimensions of abolitionist thought, organizing, and resistance.
The first section explores abolitionist theorizing and praxis in Canada through a theoretical lens of prison studies, autoethnography, decolonial studies, Black feminism, and Indigenous knowledges. As both subject and method of the dissertation, I engage ideas of intimacy and their practices through their relationship to state violence at carceral sites including prisons, policing, borders, as well as through purported care institutions such as hospitals and social work. I contrast state policing of intimacy through mechanisms such as the prison visit, strip search, and managing community contact with incarcerated people to the building of intimacy through relationships and organizing with people inside. The history of the prison in Canada and its ongoing relationship to settler-colonialism, anti-Blackness, classism, ableism, homophobia and transphobia, and transmisogyny and sexism are theorized in relationship to the ongoing struggles of prisoners for justice and liberation.
The second section of the work, Canada is so Polite, is a poetic, creative non-fiction and journalistic exploration of state violence in Canada; activist resistance to criminalization, policing, and deportation; as well as a personal exploration of family histories of colonialism and my own relationship to and location within the settler state that is Canada. In four movements, the book explores sites of advocacy and organizing against confinement and deportation; my personal histories and perspectives as a Black woman and daughter; sites of encounter with settler-colonialism such as statues, military conferences, and social cultures; and activist and abolitionist futures.
In the final section, I explore the personal and communal commitments that work towards building an abolitionist ethic based in collective principle and care.

abstract: PhD


title: The Design and In-Vitro Validation of Therapeutic CRISPR Base Editing and AAV-9 Gene Therapy for the Treatment of Classic Galactosemia

contributor:
Walia, Jagdeep
Neuroscience Studies

subject: CRISPR, Base Editor, Classic Galactosemia, Galactosemia, AAV, Gene therapy, Gal-1P, galactose, gene editing, therapy, CG

abstract: Classic Galactosemia (CG) is a potentially fatal genetic metabolic illness characterized by the inability to effectively metabolize galactose. This disease manifests as various neurological, reproductive, and systemic symptoms and is currently incurable with limited treatment options. There are currently 240 genetic variants of CG with the most predominant being Q188R a point mutation resulting in a glutamine to arginine substitution. In this study, we tested in vitro two methods for the treatment of Q188R CG, an AAV-9 gene replacement therapy, and a CRISPR cytosine base editor therapy. We observed that our AAV-9 expression plasmid for human GALT enzyme successfully restored enzyme levels in the substitution in Q188R homozygous patient fibroblast cells as shown through western blotting. However, biochemical correction still needs to be confirmed. Further, we showed successful cytosine base editing at the mutation target site resulting in reversal of the amino acid transition in the same fibroblast cell line. Together these results demonstrate the potential of both AAV-9 gene therapy and cytosine base editing to treat Q188R CG.

abstract: M.Sc.


title: Ultrasound based Bi manual Gesture Detection using MVDR Beamforming and Machine Learning

contributor:
Stewart, James
Computing

subject:
gesture recognition
human computer interaction
HCI
MVDR
beamforming
machine learning
bi manual
two handed
ultrasound
Match Filter
linear frequency modulated chirp
MEMS microphone
LRCN
convLSTM
gesture
gesture detection

abstract: This thesis presents the development and validation of an ultrasound based bi-manual gesture detection system using beamforming and machine learning.  Hardware consisting of an array of eight MEMS microphones and an ultrasonic transducer was designed and built.  Software was developed to convert the hardware output into depth images of the user's gesturing hands.  The depth images from multiple users were used to train a neural network, which permitted gesture classification of both one handed and bi-manual gestures. Average gesture classification accuracy was 93\% when trained with a single user and 82\% when trained with multiple users.

abstract: M.Sc.


title: Schrödinger’s Gap: Autonomous Weapons Systems and Legal Liability

contributor:
Robinson, Darryl
Law

subject:
artificial intelligence
autonomous weapons systems
engineering ethics
international criminal law
international humanitarian law
international law

abstract: This thesis examines issues surrounding the development and deployment of autonomous weapons systems (hereafter “AWS”) from two perspectives: a legal perspective (particularly in the context of international legal frameworks, such as international criminal law and international humanitarian law) and an engineering perspective (particularly involving issues of engineering ethics and professional responsibilities). Much attention has been paid to the development and deployment of AWS in recent years. Not only have the operational capabilities of AWS (including their accuracy, reliability, and deployability in a variety of different conditions) been called into question, but so too has their legal status, as well as the liability for any illegal acts associated with their deployment. In particular, the potential “gap” in liability associated with AWS (where a crime has been committed by an AWS without a clearly identifiable human actor to whom responsibility may be assigned) has been the source of much concern and consternation on the part of legal experts, human rights activists, engineers, and computer programmers. While the ultimate status of this “gap” will be determined by a court at a later date when the first cases involving AWS are inevitably heard, I believe that it does not truly exist, and that ultimate liability instead rests with the engineers and computer scientists responsible for the development of the AWS themselves. Furthermore, I support Dr. Daniele Amoroso’s call for a requirement of “meaningful human control,” an operational requirement that would circumvent the issue of a liability “gap” altogether. The only true potential “gap” in liability that remains is one that is wholly artificial: a gap wherein engineers, computer scientists, and other STEM professionals are actively sheltered from criminal liability, particularly by those governments and/or organisations wishing to benefit from their knowledge.

abstract: LL.M.


title: Analytical and Experimental Study of Perturbed Abrupt Fiber Tapers and Their Sensing Applications

contributor:
Yam, Scott
Electrical and Computer Engineering

subject:
abrupt taper
bending
coupling
fabrication imperfection
fiber-optics
single-mode fiber
sensing
strain
single-wavelength
torsion
coupled-mode theory

abstract:
Optical-fiber sensors are vastly employed in sensing applications due to their immunity to electromagnetic interference, high sensitivity, environmental ruggedness, and compactness. The development of fiber-optics technology introduced many matured sensor technologies, such as fiber Bragg grating (FBG) and long-period grating (LPG). However, the fabrication and interrogation of these sensors are costly and complex. Instead, fiber-taper (FT) can be quickly fabricated with the standard fiber-optics components, namely the single-mode fiber and fusion-splicer. So, FT has been considered as a sensing component in several sensing applications.

Despite FT fabrication's convenience, it is prone to some imperfections inducing a bend in its structure, not theoretically addressed in the literature. Thus, in our research, the bent-taper is analytically studied through a new mode-coupling formalism.  Moreover, we have established a relation between the bending curvature and the emergence of new modes.  Afterward, we optimized our model with the simulated annealing method to match the spectra of several FTs, and a new modal decomposition technique for FTs was developed. We have then statistically examined the modal content of a series of fabricated FTs, showing the excitation of distinct modes due to perturbations.

On the application side, the FTs' can be employed to form in-line interferometric fiber-sensors. In contrast, their sensing interrogation needs spectral measurements with such bulky and pricy instruments as broadband source (BBS) and optical-spectrum analyzer (OSA). Alternately, this thesis has proposed a new interrogation setup for these sensors comprising a laser source and a photodetector, significantly reducing future integration cost and complexity. In our work, the sensor's design parameters are conditioned to satisfy a single-wavelength measurement. Then, supporting our theory, several sensors were fabricated and examined for the strain sensing application.

The FTs have been reviewed primarily for the refractive index and strain sensing. Nevertheless, in this research, torsion measurement is introduced as a new application of these sensors. So, a setup is proposed combining epoxy with the conventional in-line FT sensors. The epoxy's spectral filtering effect upon the sensor's response is experimentally characterized. The sensor's response under strain and torsion is modelled and experimentally confirmed, exhibiting high sensitivity upon applied tension and torsion.

abstract: PhD


title: APPLICATION OF INDUCTIVELY COUPLED PLASMA SPECTROMETRY TO THE DETERMINATION OF POTENTIALLY TOXIC ELEMENTS IN WHEAT AND MISWAK FROM SAUDI ARABIA

contributor:
Beauchemin, Diane
Chemistry

subject: analytical chemistry

subject: bio-accessibility

subject: isotope ratio

subject: potentially toxic elements

subject: on-line leaching method

subject: risk assessment

subject: pollution

subject: inductively coupled plasma mass spectrometry

abstract:
The accumulation of potentially toxic elements (PTEs) in plants from anthropogenic activities represents an important environmental pollution problem when these concentrations exceed the permissible levels. A method based on electrothermal vaporization coupled to inductively coupled plasma (ICP) optical emission spectrometry was developed for the direct analysis of miswak (natural toothbrush) in 77 s, as a first step in the risk assessment process.  This method eliminates the need for digesting solids and the associated issues of contamination and loss of analyte. However, risk assessment cannot be based solely on total concentrations as only the bio-available fraction (i.e. the fraction entering the blood stream) can exert a toxic effect. For a more realistic risk assessment, bio-accessibility (the fraction dissolved in the gastrointestinal tract), which is equal to bio-availability in the worst case scenario, was measured using an on-line leaching method simulating the human gastrointestinal tract.  This method afforded the continuous monitoring of elements by ICP mass spectrometry as they were released from wheat and miswak. The bio-accessibility data obtained using this dynamic model were reproducible and comparable with those obtained by a conventional batch model despite taking 15 min instead of over 4 h. The bio-accessibility results were also used as part of a human health risk assessment where they were compared to tolerable daily intake values.
Application of the on-line leaching method to freshly collected miswak as well as miswak exposed to vehicular traffic for a few days revealed the contamination that resulted from this source of pollution.  Moreover, multiple peaks in the temporal profiles measured during on-line leaching confirmed an additional source of contamination, which was further confirmed by correlations between the leaching profiles of different elements and between Pb isotopes.  In fact, the resulting 206Pb/207Pb isotopic ratio matched that of Pb previously added to gasoline as an anti-knocking agent, suggesting that leaded gasoline is still in use in Saudi Arabia. Application of the same method to wheat from different regions of Saudi Arabia similarly revealed this source of Pb in wheat from Safeer.  It also indicated coal combustion as a source of Pb in wheat from Safeer and Qassim.

abstract: PhD


title: NUMERICAL MODELLING THE IMPACTS OF HURRICANE FLORENCE (2018) ON COASTAL NORTH CAROLINA, USA

contributor:
Mulligan, Ryan
Civil Engineering

subject:
Tropical Cyclones
Spectral Wave Modelling
Coastal Hydrodynamics
Energy Dissipation
Ocean Currents
Barrier Islands

abstract: Hurricanes have high winds that can generate strong ocean surface circulation, large surface waves and storm surges. In a typical year, several hurricanes form over the Atlantic Ocean and interact with the continental shelf making landfall on the east coast of North America. In 2018, Hurricane Florence crossed the narrow continental shelf then made landfall in Onslow Bay, North Carolina, USA. Onslow Bay is a 160 km curved embayment rimmed by barrier islands and narrow back-barrier lagoons. Two large-scale investigations of Hurricane Florence are completed by using a hydrodynamic model and two different model grids: Delft3D with a structured grid and Delft3D-Flexible Mesh with an unstructured grid. The large-scale models were used to analyze the waves, currents and storm surges generated by a major storm that moved across the continental shelf and onto the coastline. This study aims to gain insight into the affects a landfalling hurricane has offshore on the continental shelf and nearshore on beaches and in back-barrier lagoons. Model results are validated at twelve sites, and the model is used to spatially explore the waves and hydrodynamics. The deep and shallow water source terms that control the generation and dissipation of the surface wave field are examined over the continental shelf by using the structured model, Delft3D. The unstructured model, Delft3D-Flexible Mesh, is used to investigate the hydrodynamics of four barrier island systems located throughout Onslow Bay. The results conclude that the impacts of a hurricane at landfall vary based on the shape of the coastline and the intensity and track of the storm. Overall, this research contributes to a better understanding of hurricane wave processes on the continental shelf and the storm surge response of different barriers island systems.

abstract: M.A.Sc.


title: Three Essays in North American Economic History

contributor:
Clark, Robert
Economics

subject:
Economic history
Caisse populaires
Desjardins
Green Books
Public Accommodations
Segregation

abstract: This thesis studies two marginalized groups in North American history--French Canadians in the early 20th century and African Americans in the mid 20th century. Chapter 2, co-authored with Bill Dorval, investigates the impact that the arrival of access to financial services had on economic and demographic outcomes for rural French-Canadians in unbanked areas of Quebec. Using propensity score matching, I find that the establishment of a caisse populaire (a type of credit cooperative) accelerated rural population growth in treated parishes over 1910 and 1920. These effects persisted into the following decade. Chapters 3 and 4, co-authored with Lisa D. Cook, Maggie E.C. Jones, and Trevon D. Logan, use the Negro Motorist Green Books to quantify and study discrimination in public accommodations against Black Americans before the passage of the 1964 Civil Rights Act. These guides were a tool used by Black motorists to locate hotels, motels, and other businesses that would treat them with dignity. Chapter 3 describes the digitization of the guides and the spatial distribution and temporal trends of public-facing businesses that treated African Americans consumers on a non-discriminatory basis. Chapter 4, considers the relationship between the racial composition of markets and the number of Green Book listings across different industries. The exogenous change in the racial composition of a county brought on by WWII mortality of White soldiers is used to identify the relationship. WWII deaths led to an increase in the number of consumer-facing businesses that served African Americans. Next, I use a model to explore a potential mechanism: non-prejudiced firms may decide to discriminate when they face a subset of White consumers who have a distaste for consuming alongside Black consumers. An implication of the model is that in equilibrium the ratio of non-discriminatory to discriminatory firms should respond to the Black-White population ratio. This is tested empirically with data about hotels and motels. Using WWII White deaths as an instrument for the Black-White population ratio, I find that a 1 percent increase in the Black-White population ratio is associated with a 2 percent increase in the ratio of non-discriminatory to discriminatory firms.

abstract: PhD


title: Wireless Sensing for Ground Engaging Tools

contributor:
Hassanein, Hossam
Electrical and Computer Engineering

subject:
sensor node
sink
hardware design
ground engaging tool
shovel teeth
proximity sensor
harsh environment
entropy
entropic sensing
entropic filter
wireless sensor network
internet of things
industrial internet of things
time series
energy efficiency
Shannon's entropy

abstract:
A long-standing industrial problem is tackled with an industrial internet of things (IIoT) application. This thesis presents the hardware design and development of a wireless sensor network for monitoring ground engaging tools of earth processing
equipment. This work addresses several challenges in the hardware design. The challenges included establishing wireless communications from within a metallic enclosure, Investigating the effect of antenna tuning on the link budget, designing a protective package for the sensor node (SN) to withstand vibrations and mechanical shocks, and creating a low-power design that allowed for a minimum battery life of one year. Furthermore, this work puts forward the design of novel application-specific sensors including a low-power ferrous-selective proximity sensor and a low-cost capacitive wear-level sensor.
Hardware designs were evaluated with laboratory and field tests. The conducted tests demonstrated the SN’s functionality and performance in harsh operating conditions. The journey from problem definition and to successful field testing of the
complete wireless sensing solution is covered in this thesis.
In addition, a novel energy-efficient approach to wireless real-time sensing is presented. For an SN transmitting samples of a discrete time-series in real-time, its lifetime depends primarily on its battery capacity. With most of the energy consumed in wireless transmission, this thesis introduces an energy-efficient scheme that significantly reduces the number of transmitted samples, while maintaining a low mean absolute error between the original and the recovered signal. The concept of instantaneous entropy is introduced and a computationally-efficient iterative formula for computing Shannon’s entropy is derived. The SN evaluates the information content in each sample and decide whether to transmit or omit the sample. At the sink, incremental machine learning is used to recover the omitted samples in real-time. This approach shows an average of 60% reduction in energy consumption by the SN with less than 2% mean absolute error in the recovered signal. The simulation employed stationary, non-stationary, chaotic, and random time-series for performance evaluation and  benchmarking.

abstract: PhD


title: Indian Day Schools in Michi Saagiig Anishinaabeg Territory, 1899-1978

contributor:
Christou, Theodore
Education

subject:
Indigenous education
History of Education
Indian Day Schools
Two-eyed Seeing
Curve Lake First Nation
Anishinaabe History
Indigenous community-based research

abstract: This dissertation examines the history of Curve Lake Indian Day School between, 1899-1978 situated in the larger context of Indigenous education in Ontario during the first three quarters of the 20th century. Drawing on a collection of over 10,000 primary sources from the federal government, newspapers, and local archives the dissertation demonstrates how the federal government failed to recognize inherent treaty rights and fulfill its fiduciary duty towards education with Curve Lake First Nation. The federal government–through the administration of the Methodist and United Church–significantly underfunded the schools in comparison to the public system in Ontario and banned the use of Indigenous languages. This racially segregated system provided inadequate and poorly educated teachers, that caused significant issues among community members including abuse, loss of language, and dangerous health conditions. This pattern of mismanagement is still impacting their descendants today, especially with their health and revitalization of the traditional language: Anishinaabemowin. Using the method of “two-eyed seeing” this research was guided and informed by Curve Lake First Nation ensuring that all the historical data examined was easily accessible by the community through its elected Band Council under the leadership of Chief Emily Whetung.

abstract: PhD


title: Nonlinear Ferromagnetic Effects on Magnetic Barkhausen Noise Measurements of Steels

contributor: Physics, Engineering Physics and Astronomy

subject:
Magnetic Barkhausen Noise
Ferromagnetism
Electromagnetism
Non-Destructive Testing
Nonlinear Superposition

abstract:
MBN probes measure Magnetic Barkhausen Noise (MBN), a magnetic signal produced when the magnetization of a ferromagnetic material changes state. Usually a dipole (two-pole) MBN probe is employed, which needs to be physically raised, and re-oriented, in order to induce and observe MBN signals from different directions. A tetrapole (four-pole) MBN probe, however, can use the principle of superposition to accomplish the same. Superposition allows tetrapole probe measurements to be performed more rapidly and without the repositioning errors associated with the dipole probe. However, past results from tetrapole MBN probes were inexplicably different from those obtained using a dipole MBN probe. The physics underlying a tetrapole MBN probe was the focus of the present thesis research.

It was found that flux superposition is nonlinear in ferromagnetic material, whereas theory originally developed for tetrapole probe superposition had assumed linearity. In-sample flux density was modelled incorporating the effects of nonlinearity and anisotropy. It was also found that,
1) The MBN probe’s measure of in-sample flux density is usually inaccurate due to nonlinearity and flux spread in the sample, however the measure is accurate for a specific range of flux densities.
2) In-sample surface flux density is proportional to the square-root of the sum square of the MBN signal, and hence, may be inferred from the MBN.
3) There is a fundamental connection between MBN and ferromagnetic processes such as hysteresis and initial magnetization. An empirical magnetization model was developed, and derivation of a first-principles micromagnetics model was initiated.

This work has explained the formerly inexplicable data obtained from performing superposition measurements using the tetrapole MBN probe, making the probe useable at low applied fields in a sample having a single easy axis. To simplify confounding factors, however, it is recommended that future material studies using MBN be done using the dipole MBN probe.

abstract: M.Sc.


title: Broad-spectrum inhibitor of bacterial polyphosphate homeostasis attenuates virulence factors and helps reveal novel physiology of K. pneumoniae and A. baumannii

contributor:
Jia, Zongchao
Biomedical and Molecular Sciences

subject:
polyphosphate
polyphosphate kinase
anti-virulence
virulence factors
Gram negative opportunistic pathogens

abstract: Acinetobacter baumannii and Klebsiella pneumoniae currently rank amongst the most antibiotic-resistant pathogens, responsible for numerous infections each year. In the wake of this continuing crisis, anti-virulence therapeutics targeting bacterial polyphosphate (polyP) homeostasis have been posited as an attractive alternative to traditional antibiotics. In this work, we show that the small molecule gallein, recently proven to have dual-specificity polyphosphate kinase (PPK) inhibition in Pseudomonas aeruginosa, also exhibits broad-spectrum PPK inhibition in other priority pathogens. Gallein treatment successfully attenuated virulence factors of K. pneumoniae and A. baumannii including biofilm formation, surface associated motility, and offered protection against A. baumannii challenge in a Caenorhabditis elegans model of infection. This was highlighted most importantly in the critically understudied A. baumannii, where gallein treatment mimicked a ppk1 knockout strain phenotype of a previously uncharacterized PPK1. Subsequent analysis revealed a rare instance of two functionally and phenotypically distinct PPK1 isoforms encoded by a single bacterium. Finally, gallein was administered to a defined microbial community comprising over 30 commensal species of the human gut microbiome, where microbial biodiversity was not adversely influenced. Together, these results further emphasize gallein as a promising avenue for the development of broad-spectrum anti-virulence therapeutics.

abstract: M.Sc.


title: A MARL Approach for Finding Optimal Positions for VANET Aerial Base-stations on a Sparse Highway

contributor:
Givigi, Sidney
Computing

subject:
Reinforcement Learning
Automated Systems
UAV
Connected Vehicles
Artificial Intelligence
VANET

abstract: A Vehicular Ad-Hoc Network (VANET) helps connected vehicles send and receive environmental and traffic information, making it a crucial component towards fully autonomous roads. For VANETs to serve their purpose, there has to be sufficient coverage, even in areas where there is less demand. Moreover, a lot of the safety information is time-sensitive; excessive outage time in a vehicular network can increase the risk of fatal accidents. Unmanned Aerial Vehicles (UAVs) can be used as mobile base-stations to fill in gaps of coverage. My work is focused on the placement of mobile base-stations for rural highways with sparse traffic, as it represents the worst-case scenario for vehicular communication. The goal is to maximize the segments of road that satisfy a particular communication outage time constraint. I use Multi-Agent Reinforcement Learning (MARL) to learn the optimal placement strategy. The main benefit of MARL is that it allows the agents to learn complex strategies through experience. I propose a variation of the traditional Deep Independent Q-Learning. The modifications include an observation function augmented with information directly shared between neighbouring agents as well a shared policy scheme. I also implement a lightweight custom sparse highway simulator that is used for training and testing my algorithm. The experiments show that the proposed MARL algorithm is able to learn the placement policies that produce the maximum rewards for different scenarios while adapting to the dynamic road densities along the highway segment. The experiments also show that the model is scalable, allowing the number of agents to increase without any modifications to the code. The model also displays robustness as it is still able to resume function even after multiple single and dual-point failures. Finally, I show that the model can be generalized as the algorithm can be directly used, with similar performance, on an industry standard simulator. Future experiments can be performed to improve the realism and complexity of the highway models as well as to test the method on real-world data.

abstract: M.Sc.


title: Trajectory: A local arts and culture magazine - How brand curation and storefront design contributed to rapid social  change after the legalization of marijuana in Canada in Toronto: (2018)

contributor: Film and Media (Screen Cultures and Curatorial Studies)

subject:
Cannabis
Gentrification
Toronto
Cannabis Culture
Legalization
Dispensary
Retail Design
Interior Design
Placemaking

abstract: Trajectory is an arts and culture magazine that examines cannabis culture through retail storefront design in Toronto. This magazine aims to contribute to the growing conversation around design in the cannabis industry and its intersection with local neighborhoods. As a publication that is both high design and accessible to commercial endeavours, Trajectory will connect to art lovers and cannabis consumers of all ages. Through the examination of retail design, gentrification of cannabis in Toronto can be explored by the readers. The accompanying thesis will explain shifting social structures as a result of legalization and its impact on the cannabis culture and art. The editorial decisions are explained in depth as well as the institutions and artists that are featured in the magazine.

abstract: M.A.