title: Assessing the potential of Caenorhabditis elegans in the bioremediation of Microcystis aeruginosa

subject:
Microcystis aeruginosa
Caenorhabditis elegans
Bioremediation
Vivaparus georgianus
cyanobacteria
nematodes
microcystins
detoxification

abstract:
Reported incidences of cyanobacterial harmful algal blooms, or CHABs, are increasing across the world due to climate change and nutrient loading. CHABs can produce dangerous cyanotoxins and dominate freshwater ecosystems, causing damage. Microcystis aeruginosa is one of the most common species of cyanobacteria and can produce hepatotoxic and neurotoxic microcystins. The ecological and human impact of algal blooms are immense, and traditional CHAB remediation methods are not always adequate in eutrophic regions.
A proactive, targeted approach is needed to bioremediate CHABS. Bioremediation of CHABs with Viviparus georgianus (the banded mystery snail) is somewhat effective, as the snail filter feeds and ingests intact cyanobacteria cells, which are then translocated to the benthos in pseudofeces or feces. Although this keeps cyanobacteria from entering its disruptive colonial phase, this is temporary, as currents eventually liberate live cyanobacteria cells. Nematodes, such as Caenorhabditis elegans, are potential candidates for bioremediating this pseudofeces and feces. C. elegans have detoxification pathways which may break down microcystin. We analyzed C. elegans health and fat accumulation on a diet of toxic M. aeruginosa and found that C. elegans are able to ingest, digest and metabolize the diet. It is unclear if a diet of toxic M. aeruginosa has some health impacts, however overall, it was able to sustain C. elegans development and C. elegans were tolerant of it.
C. elegans detoxification response was analyzed on a diet of toxic M. aeruginosa, and it was found that in the presence of nematodes, microcystin concentrations first increased, and then in both the presence and absence of nematodes, they decreased to a steady concentration. It is unclear if this decrease is due to detoxification, or natural degradation. SKN-1 (a central regulatory protein to the phase II detoxification system) expression was not significantly greater on a diet of toxic M. aeruginosa, suggesting that this diet doesn’t induce a stress response. Finally, C. elegans populations were observed, and several generations of nematodes demonstrated their ability to digest pseudofeces and feces containing toxic M. aeruginosa.
Overall, these results suggest that C. elegans could be a viable CHABs bioremediation candidate in combination with V. georgianus.

abstract: M.Sc.


title: A New Fleet Management Approach Applied to Autonomous Mining Vehicles Using Q-Learning

contributor:
Sari, Yuksel Asli
Rielo, Oscar
Mining Engineering

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

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

rights: Intellectual Property Guidelines at Queen's University

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

subject:
Fleet Management System
Q-Learning
Reinforcement Learning
Mining Dispatch
Autonomous Robot Swarm
Multi-Robot Interaction
ROS
ROS Multi-Master
Autonomous System

abstract: In modern mining practices, a new goal for the industry is a fully autonomous mine. Most original equipment manufacturers (OEMs) are working towards automating their equipment or parts of the machines' functionality. The cooperation of an autonomous fleet would increase production, worker safety, and overall efficiency. A centralized computer system monitoring each piece of equipment’s individual data stream and system overall can ultimately replace today’s dispatch models. The new system can automatically dispatch all haul trucks based on measured conditions around the mine and adapts to new changes as they happen. Linear programming based dispatch systems are predetermined and require substantial time to reach optimization. These older models are rigid and inflexible; therefore, they do not adapt to the ever-changing mine environment. The proposed system can dynamically update the dispatching plan based on maintenance needs, payload material grade, vehicle queues, and traffic patterns. The centralized computer system is controlled by an artificial intelligence (AI) algorithm, called Q-Learning, that can optimize fleet dispatching in real time. The AI manages the truck dispatch by altering vehicles’ paths, changing loading and drop-off points, and managing maintenance needs. This algorithm must be trained for each installation and mine to suit individual needs and different fleet configurations. However, as fleet sizes change, knowledge from agents can be easily shared with new agents, and unnecessary trucks can be removed without affecting the entire system. A scaled-down proof of concept was created with autonomous robots to showcase the AI and fleet behaviours for specific scenarios to demonstrate the performance of the dynamically updating Q-learning based approach to dispatching.

abstract: M.A.Sc.


title: The Role of the IL-17 and IL-33 Axis in the Pathophysiology of Endometriosis

contributor:
Tayade, Chandrakant
Biomedical and Molecular Sciences

subject: Endometriosis

subject: Interleukin-33

subject: interleukin-17

abstract:
Endometriosis is a gynecological condition characterized by the growth of endometrial tissue outside of the uterine cavity. The widely accepted theory of pathogenesis, Sampson’s theory of retrograde menstruation, postulates that menstrual effluent (ME) is refluxed into the peritoneal cavity where it adheres to peritoneal structures and develops into an endometriotic lesion. It is hypothesized that the inability to clear this ME from the peritoneal cavity is likely due to immune dysfunction. Indeed, chronic inflammation is well categorized in these patients and has simultaneously been linked to both the primary symptoms: pain and infertility, as well as hallmark features of endometriosis pathology including adhesion, invasion, cellular proliferation, neo-angiogenesis, fibrosis, and innervation. In this context, the alarmin, IL-33, as well as the pro-inflammatory cytokine, IL-17A, emerged as regulators of inflammation, angiogenesis, fibrosis, and pain in several chronic inflammatory conditions but their role in endometriosis is not well understood. Therefore, the central theme of my research was to investigate whether and how IL-33 and IL-17 independently modulate the pathophysiology of endometriosis. IL-33 acts through the ST2 receptor present on several immune cells but predominantly through group 2 innate lymphoid cells (ILC2) to promote T helper (TH) 2 cytokines. IL-17A, a predominant product of TH17 cells, acts through a heterodimeric IL-17 receptor present on immune and non-immune cells. Using a series of murine models C57Bl6, RAG2-/- (ILC sufficient) and RAG2-/-IL-2r𝛾-/- (ILC2 deficient), we showed that IL-33 perpetuates hallmark endometriosis features including inflammation, cellular proliferation, and fibrosis predominantly through ILC2. For the study of IL-17A, we utilized cell lines and murine models to show that IL-17A promotes macrophage
iii
recruitment and is responsible for polarizing peritoneal macrophages to an alternatively activated phenotype (M2), the predominant pathological phenotype in endometriosis. Finally, our investigations in ME samples from endometriosis patients and controls revealed that TH17 cells were less abundant in endometriosis patients. Transcriptomic analysis of immune cells further demonstrated that ME samples have dysregulated gene expression of the TH17 pathway. Overall, this thesis identifies the molecular pathways of two key pathological cytokines in endometriosis: IL-33 and IL-17A as promising non-hormonal therapeutic targets.

abstract: PhD


title: Critical Role of Electron Leak from Mitochondrial Electron Transport Chain Complex I in Oxygen Sensing in the Rabbit Ductus Arteriosus

contributor:
Archer, Stephen
Translational Medicine

subject:
Ductus Arteriosus
Reactive oxygen species
Oxygen sensing
Electron leak suppressor
Patent Ductus Arteriosus

abstract:
Background: The ductus arteriosus (DA) connects the pulmonary trunk to the descending thoracic aorta, allowing placentally oxygenated blood to bypass the non-ventilated fetal lungs and enter the systemic circulation. The fetus’ systemic arterial oxygen tension (pO2) is <40 mmHg, maintaining the DA in a state of hypoxic vasodilation. As pO2 rises with the first breath, the DA constricts and becomes functionally closed within minutes. The oxygen sensor responsible for initiating this vasoconstrictor effect resides within the mitochondria of DA smooth muscle cells (DASMC). At birth, increased pO2 leads to increased reactive oxygen species (ROS) production by complexes I and III of the electron transport chain (ETC). These ROS act as diffusible signaling molecules and inhibit redox sensitive potassium channels causing DASMC depolarization and vasoconstriction. Complex I and III inhibitors, rotenone and antimycin A, relax the DA ex vivo by decreasing normoxic ROS production by the mitochondria, but also alter mitochondrial respiration. A new generation of electron leak suppressors, S1QEL and S3QEL, which decrease electron leak from complexes I and III respectively, can selectively decrease ROS production without inhibiting the metabolic function of the ETC complexes. These new leak suppressors may offer better understanding of the physiology of O2 sensing in the DA and also offer new therapeutic avenues for controlling DA tone in vivo.
Methods/Results: DA tissues were obtained from term rabbit kits. Using the ring bath model for measuring vessel tone ex vivo, we have shown that S1QEL causes a vasodilatory effect in oxygen induced pre-constricted DAs. In rabbit DASMC, S1QEL decreases oxygen consumption rates (OCR), while maintaining key parameters related to mitochondrial respiration. In DASMC isolated from humans, S1QEL blunts oxygen induced increases in superoxide generation. In vivo, S1QEL reverses oxygen induced constriction of the DA in term rabbit kits.
Conclusions: S1QEL, but not S3QEL, causes reversal of DA constriction both ex vivo and in vivo, suggesting an importance for Complex I electron leak during DA oxygen sensing. S1QEL decreases superoxide production in DASMC exposed to normoxia, but maintains key parameters of mitochondrial respiration, confirming the importance of ROS produced by Complex I in DA oxygen signaling.

abstract: M.Sc.


title: Examining the Consequences of Altered Insulin Signaling on the Expression of Human Amyloid-Beta in Caenorhabditis elegans

contributor:
Chin-Sang, Ian
Bendena, William
Biology

subject: insulin

subject: C.elegans

subject: Alzheimer's Disease

subject: Alzheimer's

subject: Insulin Resistance

subject: Insulin regulation

subject: DAF-2

subject: DAF-16

abstract: Alzheimer’s disease (AD) is a neurodegenerative disease that affects millions of people worldwide. This disease of ageing is the result of amyloid-beta (Aβ) plaques and tau neurofibrillary tangles in the brain, causing symptoms such as confusion, memory loss, and impaired cognitive abilities. It is well known that insulin is a key regulator of the ageing process, as well as many other bodily processes such as metabolism and fat storage. An association between insulin regulation and amyloid-beta plaque accumulation has been noted in Caenorhabditis elegans. This study uses C. elegans to investigate how decreased insulin signaling affects the deposition of human amyloid-beta in a transgenic worm strain that is expressing the human amyloid-beta protein and phenotypes associated with Aβ expression. Expression of human amyloid-beta significantly decreased adult longevity, L1 arrest survival, the number of thrashing/body bends in liquid. A significant increase in the deposition of amyloid protein was found through specific staining. Neuronal ageing was also accelerated relative to wildtype animals.  Reduced expression of the insulin receptor (DAF-2) was able to successfully rescue amyloid-beta induced phenotypes: adult longevity, L1 arrest survival, neuronal ageing, and plaque deposition. Overexpression of antagonistic insulins, INS-17 and INS-37 were not able to rescue adult longevity of L1 arrest survival. Antagonistic insulin, INS-39, was able to increase adult longevity but produced no significant rescue of L1 arrest survival. The expression of amyloid beta caused significant neuronal ageing on day 5, day 8 and day 12 of life, with the daf-2 insulin receptor mutant rescuing this phenotype. Other insulin mutants produced differing results at the different time points and showed no consistent results. None of the strains were able to restore the thrashing in liquid deficit of the amyloid-beta worm. These findings indicate the interaction between insulin and Aβ is complex, and research in this area is critical to determine possible therapeutic strategies for AD in the future.

abstract: M.Sc.


title: New ideas for tonne-scale bubble chambers and a search for superheavy dark matter with PICO-60

contributor: Physics, Engineering Physics and Astronomy

subject:
Dark matter
Bubble chambers
PICO

abstract: The PICO dark matter search experiments using bubble chambers have been successful in probing the potential WIMP-proton scattering cross section. The largest of these experiments (PICO-60 and PICO-40) contain approximately 50~kg of the superheated liquid Freon C$_3$F$_8$ in a quartz vessel. Future larger-scale bubble chambers will face technical challenges in their construction and operation. To overcome the construction challenges, the feasibility of alternative chamber materials to quartz in the form of acrylic and stainless steel, which are easier to construct in large sizes, is investigated in small-scale test chambers. The first C$_3$F$_8$~and C$_4$F$_{10}$~mixture in a bubble chamber, which could alleviate the demands on the thermal performance in large detectors, is further demonstrated confirming acoustic discrimination between nuclear recoils and alpha particles. The gamma rejection in this mixture and pure C$_4$F$_{10}$~is additionally measured for the first time. The acoustic response of bulk nucleations is found to decrease exponentially with increasing pressure while increasing exponentially with increasing temperature. This model will inform the future operating conditions of large bubble chambers which need to reach nuclear recoil thresholds above 10~keV to avoid backgrounds from the coherent elastic neutrino nucleus scattering of solar neutrinos. Finally, existing PICO-60 data is reanalyzed in a search for superheavy dark matter through its unique multi-scatter signature producing novel limits on carbon and fluorine. For fluorine, spin dependent scattering is probed up to $4\times10^{16}$ GeV$/c^2$.

abstract: PhD


title: Testing Predictors of Change in Suicidal Ideation Among Transgender and Non-Binary People

contributor:
Stewart, Jeremy
Psychology

subject:
Suicide
Transgender
Non-binary
Suicide ideation
Childhood abuse
Childhood maltreatment
Non-suicidal self-injury
Suicidal thoughts and behaviours
STBs
NSSI
Gender Minority Stress
Gender Minority Stress and Resilence
Self-injurious thoughts and behaviours

abstract: Suicide is a pressing public health concern and is among the top 10 leading causes of death. Although rates of suicidal thoughts and behaviours (STBs) are substantially elevated among transgender and non-binary (TGNB) people, risk factors for STBs are rarely tested in this group. Longitudinal research is thus needed to identify characteristics that specifically predict the escalation of STBs among TGNB people and ultimately, inform culturally competent care to curb preventable suffering and death in this high-risk community. The aim of the current study was to examine several contextual variables that contribute to suicide ideation in this population including childhood maltreatment, non-suicidal self-injury (NSSI), and gender minority stress (GMS), in a hypothesized mediation model. It was hypothesized that more severe childhood maltreatment would predict more frequent future suicide ideation, and that this effect would be mediated by increased rates of NSSI and more severe GMS. The current study included 182 gender-diverse individuals who completed an online survey at two timepoints spaced four months apart. At baseline, participants completed online questionnaires to assess gender identity (Alderson Sexuality Questionnaire, adapted; ASQ), childhood maltreatment (Childhood Trauma Questionnaire; CTQ), GMS (Gender Minority Stress and Resilience Questionnaire; GMSRQ), depression symptoms (Patient-Reported Outcomes Measurement Information System Depression scale; PROMIS-D), and a gold standard assessment of self-injurious thoughts and behaviours (Suicidal Thoughts and Behaviour Interview – Self-Report; SITBI-SR). Participants were readministered all measures at follow-up except for the CTQ. Contrary to my hypotheses, there was no direct or indirect effect of childhood maltreatment on ideation. However, there were several concurrent associations amongst all model variables consistent with previous literature using both cis- and trans-gender samples. Notably, more severe maltreatment was related to greater gender minority stress, specifically, external experiences of victimization. Additionally, there was a strong concurrent association between internalized stressors and ideation. Thus, putative risk factors for suicide ideation identified in prior studies using cisgender samples may not generalize to TGNB people under the same function. Community-specific context and correlates should be investigated further and cognitive-affective variables from leading suicide theories should be integrated to help clarify how gender diverse specific experiences may contribute to suicide risk.

abstract: M.Sc.


title: Toward Liver Tumour Segmentation in CT Scans

contributor:
Simpson, Amber
Computing

subject:
nnUNet
Liver lesion
CT
Segmentation
Preprocessing

abstract:
Semantic medical image segmentation is the process of annotating regions of interest in medical images without the need for human input. Image segmentation is the most common medical image processing task in research in the  eld, and is critically important in cancer care. Small datasets are typically a challenge for researchers who must rely on preprocessing datasets to overcome this. In the task of liver tumour segmentation, datasets can also be highly variable. This research focuses on preprocessing techniques, working with a popular generalizable semantic segmentation model, nnUNet, which generalizes to new labels of di erent anatomies by analyzing a dataset without needing to be modi ed explicitly. We considered several preprocessing techniques and improved state-of-the-art Dice Similarity Coe cient (DSC), on an open-source dataset. We used CT data from the Medical Segmentation Decathlon (MSD), a crowdsourced challenge aimed at developing and benchmarking generalizable medical imaging, as well as our own dataset of metastatic colorectal liver cancer CTs (n = 198). We used nnUNet which had the highest per task, per region, DSC across all tasks in the 2018 MSD as a baseline. Our preprocessing improved state-ofthe-art liver tumour segmentation DSC and Normalized Surface Distance (NSD) by 1.5%. Although our hierarchical segmentation process similar to conventional techniques did not improve DSC or NSD, our data grouping method which is novel to the best of our knowledge improved DSC 3.0%. All our experiments were carried out on and an NVIDIA RTX 2080Ti GPU using PyTorch.
Our contributions are as follows: we demonstrate that separating the data according to its voxel spacing improved prediction; we explored a hierarchical to segment tumours in liver CT scans; we also improved performance slightly with additional preprocessing that we believe keeps true to the design principles of nnUNet. To the best of our knowledge, at the time this was written, our method of separating the dataset according to voxel spacing is novel and does not appear elsewhere in the literature. Semantic segmentation will eventually be a fast and accurate tool for imaging assessment that will improve patient-care, reduce time for diagnosis, and expedite treatment.

abstract: M.Sc.


title: RAINBOW BEARD AND THE UNICORN KNIGHT: QUEER AND TRANS THRIVAL AND QUEERING PROFESSIONALISM IN TEACHER EDUCATION

contributor:
Airton, Lee
Education

subject:
trans
transgender
gender identity
gender expression
queer
professionalism
gender norms
gender
teacher education
teacher candidate
identity
autoethnography
focus group
a/r/tography
artography
arts
thrival
damage centered

abstract: This study seeks to explore how queer and trans (QT) teacher candidates (TC) navigate their identities as QT professionals and thrive during their initial teacher education. This thesis contains an introduction that presents the context of this study and information on me, the researcher, through an autobiographical signature. An autobiographical signature shares some aspects of my life as they are relevant to this study, such as my academic qualifications, identity, and history. Chapter 1 explains the purpose of the study and shares my research questions as well as a literature review of relevant studies that guide this work. My literature review focuses on the spaces in which QT TCs are working and learning, such as kindergarten to grade 12 (K-12) settings (on practicum), and in their teacher education programs (higher education). Literature in these contexts mainly focuses on queerness and gender norms in these spaces. With my thesis, I am interested in literature showing how QT people navigate and are impacted by these spaces. Some major concepts identified through the literature include identity conflict and development, outness, and visibility. My methodology provides a rationale for a/r/tography as a researcher autoethnographic method, using art creation and journaling to reflect, deconstruct, and learn about experiences spanning three years in one teacher education program. My use of a/r/tography is paired with a focus group, where I connect with other QT people involved in the teacher education program around QT identity and thrival. Findings from these two data sources come together in four main themes, which answer my research questions. This study has implications that are personal, professional, and theoretical: (a) personal implications include participant wellbeing/solidarity through artmaking and community engagement, (b) professional implications include positive impact on current TCs/in-service QT educators, providing insight for this and other faculties of education to improve their programs, and (c) theoretical implications include contributions to emerging work in a/r/tography and trans thrival.

abstract: M.Ed.


title: The intersection of pain, disease severity, and circadian disruption in experimental autoimmune encephalomyelitis

contributor:
Ghasemlou, Nader
Gilron, Ian
Biomedical and Molecular Sciences

subject: multiple sclerosis

subject: pain

subject: neuroinflammation

subject: circadian rhythm

abstract: Multiple sclerosis (MS) is an autoimmune disease causing neuroinflammation and demyelination to the central nervous system. The overall goal of this thesis was to explore an emerging area of research in the MS field: circadian rhythms, the 24-hour biological rhythms governing a significant number of functions at the behavioural, systems, cellular, and molecular levels. Evidence suggests that people with MS experience disruption in their circadian rhythms, and that those who are exposed to environmental sources of circadian disruption have an increased susceptibility for MS. Furthermore, people with MS often report a rhythm to their pain intensity, peaking at night. I therefore sought to investigate circadian rhythms in experimental autoimmune encephalomyelitis (EAE), a mouse model of MS, with a focus on pain outcomes. However, limitations in this model led to the pursuit of novel methodology and tools in the EAE field. First, a mild induction protocol of EAE was characterized in order to improve the study of pain; the lack of hindlimb paralysis in mild EAE mice allowed for continuous assessment of pain behaviours with stimulus-evoked testing. Second, an observer-independent assay, advanced dynamic weight bearing (ADWB), was investigated as a tool for monitoring disease progression in EAE. ADWB was shown to accurately detect shifts in weight bearing as EAE mice developed locomotor dysfunction in the hindlimbs. Third, circadian rhythms were identified as disrupted in peripheral but not central clocks of EAE mice, as seen by altered rhythms of immune cell numbers and clock genes in the spinal cord, but not of locomotor activity. Mechanical hypersensitivity, on the other hand, was rhythmic in EAE mice, peaking during the rest phase. Finally, environmental circadian disruption through altered light cycles was shown to exacerbate EAE severity and underlying neuroinflammation and demyelination. Although significant work remains to fully understand these phenomena and to translate it to people with MS, this research provides a new perspective on the role of environmental and endogenous factors in MS.

abstract: PhD


title: New insights on the distributions of freshwater turtles in southern Ontario using environmental DNA

contributor:
Lougheed, Stephen
Biology

rights: Attribution-NonCommercial-NoDerivs 3.0 United States

subject:
environmental DNA
niche modelling
turtle
hibernation
Maximum Entropy
range limit
Sternotherus odoratus
Graptemys geographica
Chrysemys picta

abstract:
Quantifying species geographical distributions and understanding factors that underlie them, has been a long-standing focus in ecology. However, obtaining unbiased, accurate species occurrence data can be challenging, especially when the organism has low abundance or is cryptic. Environmental DNA (eDNA) has emerged as a fast, sensitive, and non-invasive survey tool to infer species presence. In aquatic ecosystems, eDNA has been widely applied to inform conservation of species at risk or for early detection of invasive species, but its potential for answering more fundamental ecological questions remains relatively unexplored. In my thesis, I used eDNA and community observations to explore the northern distributions and range limits of freshwater turtles, an understudied taxon in the current era of rapid climate change:
I centered my thesis on three freshwater turtles in southern Ontario, Canada: midland painted turtle (Chrysemys picta marginata), northern map turtle (Graptemys geographica), and common musk turtle (Sternotherus odoratus). In chapter II, I focused on G. geographica and a single lake during winter, applying eDNA to detect communal overwintering sites below the ice. My work confirmed that eDNA can locate overwintering turtles and revealed a new site, which was further confirmed using a remotely controlled underwater vehicle. Chapter III focused on S. odoratus, where I used eDNA to sample waterbodies in southeastern Ontario within and beyond its known northern range. I modelled its distribution using Maximum Entropy (MaxEnt) with parameters fully optimized. I integrated eDNA detections with community observations and gained new insights on environmental variables that shape and constrain the turtle’s distribution. In chapter IV, I modelled the northern distributions of all three turtles again using optimized MaxEnt. I addressed the issue of overfitting and improved the biological interpretability of MaxEnt models by implementing variable collinearity reduction protocols. Overall, my models suggested that distributions of the turtles are shaped by thermal conditions, characteristics of aquatic habitats, and topographical features.
Collectively, my work sheds new light on aspects of spatial ecology of three temperate freshwater turtles and contributes to an expanding toolbox of methods for surveying species, identifying critical habitat, and better understanding the factors that shape or limit species distributions.

abstract: PhD


contributor:
Tolmie, Jane
Aziz, Sylvat
Lord, Susan
Cultural Studies

subject:
Trauma
Abuse
Time
Memory
Memoir
Graphic memoir
Sequential art
Handmade paper
Hand bound books
Art activism
Feminism
Psychoanalytic feminism
Affect
Creative destruction
Poetics
Poetry
Subjectivity
Materiality
Quilt
Mother
Mothering practice
Maternal theory
Childhood
Creative emancipation
Mental health
PTSD
Storytelling
Comic

abstract:
Quotidian Trauma and Everyday Pain: Emancipation Through Creative Destruction is a research-creation thesis shaped by subjective embodied memories of abuse trauma. The research-creation comprises a series of sequential graphic stories and a poetry collection. These narratives re-imagine trauma’s impact on my maternal generations. Like women’s encounters with abuse trauma, women's stories were once narrated from male perspectives based on male-centered experience. However, women’s autobiography is now a validated scholarly discipline. Similarly, graphic medicine, the practice of using visual stories of bodies to help explain medical conditions, has carved a place for women’s knowledge.

At the intersection of graphic memoir and graphic medicine, the stories in Quotidian Trauma and Everyday Pain: Emancipation Through Creative Destruction reveal my perspective on events according to my perceptions and beliefs. These are real stories of abused bodies and minds unfolding in images and words. They are thoughtful recollections filtered through the lens of trauma memory. As narrator, I tell these stories from a place in my body where trauma knowledge is stored and lives unacknowledged until it erupts, usually distorted and misunderstood. Then I deny this knowledge, forget it, rewrite it, re-store it, and finally re-imagine it through art.

My written thesis draws on trauma, psychoanalytic feminist, storytelling, and graphic medicine theories to support embodied knowledge and my attempts to translate it. Although I engage with affect theory, I don’t engage with it critically. Time’s theories are the interlocutors that insert themselves firmly into my project, unsettling chronological stories with specific events in dialogues between them. Time connects the distance between body and mind in my creative process. Time and traumatic events, once experienced, are always in the past. It is not possible to re-visit time or re-experience traumatic events. But much of this project is dedicated to trying. Quotidian Trauma and Everyday Pain: Emancipation Through Creative Destruction is a story of time, of living in and out of time, of colliding times, of aging, and multi-generations. It is a story of traumas and a process reflecting attempts to imagine an impossible order in my life through art.

abstract: PhD


title: A Theoretical Understanding of Defending Behaviours

contributor:
Craig, Wendy
Psychology

subject:
Bullying
Defending
Reporting
Comforting
Solution-Focused Defending
Aggressive Defending
Resource Control Theory
Resource Control Strategies
Attachment Security
Attachment Theory
Attachment
Developmental Psychology
Youth

abstract: Youth’s defending behaviours are associated with less bullying in the classroom (Salmivalli, Voeten, & Poskiparta, 2011) and, consequently, are critical components of bullying prevention programs (e.g., KiVa; Salmivalli, Kärnä, & Poskiparta, 2010). There is limited research regarding defending behaviours that is grounded in theory. This thesis is guided by Resource Control Theory (Hawley, 1999) and Attachment Theory (Ainsworth et al., 1978). The objectives of our studies were to investigate factors that correlate with defending behaviours. In our first study, measures of resource control strategies, social power, social connections, and defending behaviours were used. Descriptive analyses revealed differences in resource control strategies and defending behaviours by gender and grade. Cross-sectionally, being categorized as a frequent user of prosocial resource control strategies (e.g., cooperating to achieve goals; Hawley, 1999) was positively associated with comforting, solution-focused defending, and reporting, whereas being categorized as a frequent user of coercive resource control strategies (e.g., threatening others to achieve goals; Hawley, 1999) was positively associated with aggressive defending. Most of these relationships were no longer significant longitudinally. Our results suggested that resource control strategies were associated with defending strategies that were expected to serve related functions (cooperative or competitive). The second study examined the relationships among parent attachment, resource control strategies, and defending behaviour. Cross-sectionally, both trust-communication (i.e., mutual respect, discussion of problems; Muris et al., 2001) and alienation (i.e., anger and isolation; Muris et al., 2001) were positively associated with all four defending behaviours. There was no evidence of mediation by resource control strategies. Findings indicated that relationships among attachment security and defending behaviours were complex. These relationships suggested that both securely attached and insecurely attached youth may defend their peers, and that additional characteristics of parent-child relationships may relate to youth’s use of resource control strategies and defending behaviour. Together, these findings raise many questions, emphasizing the need for further theory-driven research.

abstract: M.Sc.


title: An Adaptive Design to Reduce Animal Road Mortality: Analyzing the Effectiveness of a Fence-Culvert Ecopassage Design on Highway 401, Ontario

contributor:
Danby, Ryan
Environmental Studies

subject:
Road ecology
Road mitigation
Culvert
Herpetofauna
Road mortality
Turtle
Habitat connectivity
Barrier fencing
Highway 401
BACI design

abstract: Road mortality has become a serious threat to turtle populations. Mitigation strategies using exclusion fencing and some form of crossing structure are becoming increasingly common, yet studies that evaluate the efficacy of these designs still remain rare. Field monitoring that was conducted from 2014-2017 had identified a 1 km stretch of Highway 401 in eastern Ontario with especially high levels of wildlife mortality, including the endangered Blanding’s turtle (Emydoidea blandingii). In 2018 the Ontario Ministry of Transportation installed two types of fencing in this location to prevent animals from entering the roadway and to funnel them into existing drainage culverts to allow for habitat connectivity. The goal of this research was to evaluate the effectiveness of the fence-culvert design by collecting two years of post-mitigation road mortality data, and then comparing this to the pre-installation data. I implemented a before-after-control-impact (BACI) study design to interpret and assess the results. In addition to road mortality surveys, a combination of camera trapping, sand trapping, and field observations of wildlife behavior were used in the post-mitigation survey years. Kernel density analysis (KDE+) was used to analyze the mortality data and showed that the mitigation structure was effective in reducing turtle and mammal mortality, but also suggested that the fencing may have contributed to an increased mortality of snakes. Camera trapping at culvert entrances indicated that the majority of complete crossings through the culverts were mammals (97%), with few herpetofaunal crossings (3%). Nevertheless, there was a distinct presence of herpetofauna at the openings of culverts (n=789), suggesting that adequately sized and configured ecopassages may aid in connectivity. Based on these results, as well as ongoing maintenance considerations, I conclude that a ‘best practice’ design to reduce road mortality of turtles and other wildlife on Highway 401 may be the installation of 3/8” chain link fence with a ground- level screen of fine mesh or smooth plastic (~30cm), adequately sized and designed ecopassages, and full coverage fencing of pre-defined hot spot locations of mortality.

abstract: M.E.S.


title: Terminal Loneliness: A Three-Phased Phenomenological Study Exploring Previously Suicidal Youth’s Experiences of Belonging to Caring Others During Suicidal Episodes

contributor:
Berg, Derek
Education

subject: Belonging

subject: Suicide prevention

subject: Youth

subject: Loneliness

subject: Qualitative

abstract: How can we inspire hope in youth (18–24-year-olds) who want to end their life? Suicide remains the second highest cause of death for youth (Statistics Canada, 2020). The pandemic has only increased the prevalence of suicidal thoughts and behaviours among youth (Yard et al., 2021). Belongingness may hold life-saving answers to stemming this tide. Leading frameworks for understanding suicide as a journey from ideation to attempt put belongingness at the nexus of prevention. Joiner (2005), the pioneer of these frameworks, explains that if belongingness persists “the will to live remains intact” (p. 117). Researchers, however, have yet to capture the ebb and flow of belongingness and the role close others might play throughout the suicidal episode. One enigmatic anomaly at the root of researchers’ pursuit to place belongingness is a pervading deep sense of loneliness despite the explicit caring presence of others. By listening to the stories of 20 youth with past suicidal episodes, this work offers a visceral window into the impenetrable fog of suicidal desire. This study was designed using Interpretative Phenomenological Analysis (Smith et al., 2009). Data were collected online from interviews and joint storytelling sessions, a focus group, and four supplemental data sources. Thematic patterns were identified by arranging clusters of colour-coded significant statements on a reflective wall. Fine-grain individual accounts were developed before considering patterns across cases. Youth stories shine a light into three life-saving insights surrounding belongingness: what psychosocial needs knit together to form the core DNA of the construct, how intrapersonal and interpersonal fractures in belongingness along the suicidal path increase suicidal desire, and when and how caring others can interrupt a youth’s path to suicide.

abstract: PhD


title: Learning Support for Managers in the Canadian Federal Public Service

contributor:
Stockley, Denise
Education

subject:
Public Service
Supervisor Support
Canadian Public Service
Survey
Manager Support
Workplace Learning

abstract: In the Canadian Federal Public Service, workplace learning is used to teach managers about important topics related to their role.  Access to these types of courses is critical as managers, in particular lower-level managers, have the largest number of direct reports.  These managers’ decisions influence individuals, groups of employees and ultimately the department they work for.  For example, in the case of a harassment or discrimination complaint, how a manager manages the situation can impact not only the mental health and wellbeing of the employees involved, but how the Canadian public views the department.  Given the potential impacts a manager’s knowledge, and subsequent ability, has on both individuals and the public’s perception of their department, understanding how we can best support managers’ learning is instrumental in the effectiveness and efficiency of the organization in question.  This research was conducted using survey research design and data were collected via an online questionnaire.  The aim of this research was to investigate the attitudes and opinions of Managers in the Canadian Federal Public Service about the level of support received to complete mandatory and professional development courses.  The primary theme that emerged from this research is that managers struggle to find the time to complete training.  Time was mentioned by respondents when asked about mandatory training, developmental training, and support pre and post COVID-19.  In every instance, time was identified as the most limiting factor.  Findings imply that in order to support managers in the Canadian Federal Public Service, more efforts are needed to do more to provide managers with dedicated time to complete training.  The pandemic has increased workloads, and added confounding factors for some, well trained managers are needed more than ever to assist employees navigate the new and highly virtual workplace that they find themselves in.

abstract: M.Ed.


title: CO2-Switchable Foaming Agents

contributor:
Stubenrauch, Cosima
Jessop, Philip G.
Chemistry

subject:
CO2 switchable surfactants
Foam

abstract: The work presented in this thesis focuses on expanding the use of CO2-triggered switchable surfactants for switchable foam stability. Three CO2-responsive switchable cationic surfactants (SCS) with switchable heads were first explored namely, two acetamidines and one dimethylalkylamine. Acetamidine surfactants were found to be inappropriate for foam studies as they hydrolyze when added to water. However, it was possible to study the foam properties of N,N-dimethyltetradecylamine (C14DMA) in the presence and absence of CO2. In the absence of CO2, C14DMA is a water insoluble organic molecule unable to generate foam. In the presence of CO2, the dimethylalkylamine head group becomes protonated and transforms C14DMA into a cationic surfactant that is able to generate foam with moderate stability. Note that the use of CO2 as the dispersed gas always leads to unstable foams due to its high solubility in water resulting in fast coarsening. More stable foams are thus generated with the protonated surfactant and a less soluble gas such as N2. However, continuous N2 dispersion eventually displaces the CO2 in the solution thus deprotonating and “deactivating” the surfactant. Therefore a new class of CO2-switchable surfactants were synthesized to stabilize foams in the presence of an inert gas, such as N2, and prevent foam generation in the presence of CO2. This new class is called CO2-responsive cationic tail switchable surfactants (STSs). These surfactants have a typical polar head group (either cationic, anionic, or non-ionic) while the CO2-responsive group is placed in the middle of the hydrocarbon tail. With aqueous solutions of these molecules one can generate foam with N2. In the presence of CO2, the trialkylamine becomes protonated and disrupts the amphiphilic nature of the surfactant molecules, thus eliminating or decreasing the surfactants ability to produce foam. The STSs synthesized and investigated in this thesis were 5-(heptyl(methyl)amino)-N,N,N-trimethylpentan-1-aminium bromide (C12N(Me)TAB), sodium 4-(methyl(octyl)amino)butane-1-sulfonate (C12N(Me)SSn), and 8-(butyl(methyl)amino)octyl-myo-inositol (C12N(Me)I). To understand the foaming properties of these surfactants, the time evolution and the structure (liquid fraction, bubble size, and bubble size distribution) of the foams generated were studied.

abstract: M.Sc.


title: Occupational Solar Ultraviolet Radiation and Breast Cancer Risk

contributor:
King, Will
Public Health Sciences

subject:
UVR
Solar UVR
occupation
breast cancer

abstract:
Background: Solar ultraviolet radiation (UVR) has potential protective and confirmed detrimental effects on cancer risk. Several studies have examined recreational sun exposure in relation to breast cancer risk, and a recent meta-analysis found that moderate sun exposure (1 to <2 hours/day) was associated with a decreased risk of breast cancer. Only one previous study in Canada has investigated sun exposure and breast cancer risk in an occupational setting. The objectives of the present study were to investigate the relationship between occupational solar UVR and breast cancer risk in Canada.
Methods: A case-cohort study was conducted utilizing data from the Canadian Partnership for Tomorrow's Health (CanPath) prospective cohort study. Questionnaires were completed at baseline to obtain information on sun exposure, current and longest job held, and breast cancer risk factors. Cancer outcomes were ascertained via linkage with provincial cancer registries and administrative databases. Longest held job at baseline was linked to a job exposure matrix to assign exposure to occupational solar UVR. Breast cancer risk estimates (hazard ratios [HR]) and 95% confidence intervals were estimated using a weighted Cox proportional hazard’s regression model with age as the timescale.
Results: A total of 1,822 breast cancer cases met eligibility criteria from the underlying cohort and a random sample of 7,361 female participants were selected for the subcohort. The prevalence of occupational exposure to solar UVR was 2.2% in the case-cohort. HRs (1.14 (95% CI 0.84-1.54)] do not suggest that occupational solar UVR has a protective or detrimental effect on the risk of breast cancer for Canadian females. When analyzed by menopausal status, the risk for pre-menopausal breast cancer was elevated, but not statistically significant (HR=1.66 [95% CI 0.93-.95]). Occupational solar UVR was not associated with the risk of breast cancer for post-menopausal Canadian females.
Conclusion: Previous research has focused on recreational sun exposure. The present study is the second to examine the relationship between occupational sun exposure and breast cancer in Canada and suggests that occupational exposure to UVR, may increase breast cancer risk in pre-menopausal females.

abstract: M.Sc.


title: Trends of Halogenated Flame Retardants in Herring Gull across Canada from 2008 - 2019

contributor:
Orihel, Diane
Friesen, Vicki
Biology

subject:
Flame retardant
Herring gull
Biomonitor
Stockholm Convention
Temporal trends

abstract: Halogenated flame retardants (HFRs) are chemicals that are used to reduce the flammability of objects and are of international concern due to their negative effects on the environment and human health. Some HFRs have been regulated under the Stockholm Convention on Persistent Organic Pollutants that aims to protect human health and the environment. To address whether such international regulations are reducing concentrations of HFRs, temporal trends of polybromodiphenyl ethers (PBDEs), hexabromocyclododecane (HBCDD), and dechlorane plus (DP) were examined in herring gull (Larus argentatus smithsonianus) eggs. Eggs were sampled from 18 Canadian colonies located in the Laurentian Great Lakes, Niagara River, St. Lawrence River, the Atlantic, and the Arctic. One egg was sampled from each of 10-15 individual nests from each colony for 5-12 years and pooled within colonies and years on an equal wet weight basis. Egg pools were analyzed using gas chromatography-mass spectrometry for 14 PBDE congeners, total-a-HBCDD, and syn- and anti-DP. Generalized linear models and breakpoint analysis was used to determine if, and when, changes in concentrations occurred and the direction of these changes. I found few significant declines of flame retardant concentrations over time in herring gull eggs, and therefore, there was little support for the hypotheses that either 1) the nomination of a flame retardant or 2) the listing of a flame retardant reduces its concentrations in herring gull eggs. These results support that flame retardants are still emitted to the environment due to stockpiles, discarded products, or re-release of environmental reservoirs after their regulation. These results show that in only a few cases management due to the Stockholm Convention reduced concentrations of HFRs in Canadian herring gull eggs, but that overall concentrations had not begun to decrease between 2008 and 2019 in response to regulation. However, declines in HFR concentrations may not have occurred during this study period since a longer time frame may be required before significant declines concentrations due to SC management are seen. Additionally, the SC’s importance may be the framework it provides to signatory parties for generating their own national regulations.

abstract: M.Sc.


title: Gender Equity in Physics Education: Framing the Future of Physics Education Research in Canada

contributor:
Colgan, Lynda
Education

subject:
Physics education
Gender equity
Physics education research
Higher education
Equity, diversity, and inclusion

abstract:
The overarching purpose of this dissertation is to determine if and how the field of physics education research (PER) in Canada is addressing issues of gender inequity in physics education, and to develop an expert knowledge-based framework to guide Canada’s ongoing PER to increase gender equity in physics education. Three separate but related research phases were designed to achieve this purpose and address specific research questions: What can be learned from PER experts about supporting gender equity in physics education? What is the landscape of PER in Canada; who are our PER experts and what are their areas of research focus? What do Canada’s experts consider to be the most pressing needs and priorities to address the gender equity issue? And what is a framework that could guide and support Canada’s ongoing PER to achieve gender equity in physics education? The research questions were approached with a pragmatic worldview, a feminist and critical theoretical lens, and a qualitative-dominant mixed-methods paradigm, and addressed using qualitative and mixed-methods methodologies—content analysis, interviews, questionnaires, and the Delphi technique.
Phase one describes the sought-after lessons from experts in gender equity PER in the form of three major themes relating to what is currently known and unknown about gender equity in physics education, moving toward gender-equitable physics education, and conducting and using PER as a tool. Phase two describes, for the first time, the landscape of PER in Canada in terms of characteristics of Canadian PER engagers and their areas of research focus, as well as five themes representing this complex field with challenges to its members and progress. Phase three describes resulting consensus levels from the Delphi process concerning what Canada’s physics education researchers consider to be priorities for addressing gender inequity in physics education, as well as six themes representing the commentary during this structured communication process. The data from all three phases of this research are synthesized and integrated into an iterative framework intended to guide, both practically and theoretically, ongoing PER in Canada to increase gender equity in physics education.

abstract: PhD


title: A MULTI-METHOD INVESTIGATION OF INDEPENDENT AUDIT REGULATORS: EVIDENCE AND IMPLICATIONS

subject:
Audit inspections
Regulatory focus
Regulatory capture
Audit regulators

abstract: This thesis uses multi-methods to examine the effectiveness and implications of independent audit regulators, such as the Canadian Public Accountability Board (CPAB) in Canada and the Public Company Accounting Oversight Board (PCAOB) in the United States, whose mandates include improving audit quality through periodic inspections of auditors’ work. In Study 1, I use experimental method to examine how regulators’ inspection feedback anchor interacts with audit firms’ national office style to impact audit partners’ commitment to the goal or reducing aggressive client income and the strategy audit partners intend to undertake to negotiate with their clients. I find that, conditional on having an antagonistic regulator – one that provides feedback anchored on failure – audit partners are less committed to their goal when they work with a collaborative national office than when they work with a prescriptive national office, and they are more inclined to seek win-win with the client. I also find that conditional on working with a collaborative national office, audit partners are more committed to their goals if the audit regulator’s feedback anchors on opportunities to improve rather than on failure. In Study 2, I use archival method to empirically examine CPAB’s inspection results for Canadian audit firms. Based on hand-collected data from CPAB’s and PCAOB’s inspection reports, I find that CPAB consistently reports a lower deficiency rate than PCAOB for the same large accounting firms under inspection (i.e., Canadian Big 4 accounting firms), and reports fewer areas of deficiency than PCAOB for the same large accounting firms inspected. Further analysis shows that CPAB also discloses much less information than PCAOB, consistent with what one would expect from a regulator being captured by the interest of large regulatees. Together, these studies extend existing accounting literature on audit regulations and have practical implications for audit regulators and audit firms.

abstract: PhD


title: Kinetic Modeling of Radical Homo-, Co- and Terpolymerization in Alcohol/Aqueous Solutions

contributor:
Hutchinson, Robin A.
Chemical Engineering

subject:
Solution polymerization
Radical polymerization
Isotope effect on molar mass
Kinetic modeling

abstract:
Multi-functional polymers used for personal care products can be modified post-production or be used “as-is” to simplify formulations, while providing the same properties as a mixture of polymers. Typical compositions consist of acrylic acid (AA) copolymerized with non-functional monomers such as methyl acrylate (MA) and N-tert-butylacrylamide (t-BuAAm) synthesized by radical polymerization in alcohol/water solutions. However, solvents capable of forming or disrupting hydrogen bonds cause the polymerization kinetics of acrylate and acrylamide monomers to deviate from those observed in bulk or non-polar solvents. Though a good foundation of literature has been developed for the solvent-based kinetics of hydrophobic acrylates in organic solvents and hydrophilic acrylates and acrylamides in water, there is limited knowledge as to how the kinetics evolve as the solvent transitions from organic to aqueous.
In this work, the impact of hydrogen bonding solvents on the kinetics of homo-, co- and terpolymer systems is systematically studied using in-situ NMR batch experiments to investigate how reaction temperature, initial monomer content, comonomer composition and ethanol/water ratio in the solvent mixture affect the rate of monomer conversion, copolymer composition drift and final polymer molar masses (MMs). Furthermore, the results from a pulsed laser polymerization investigation are used to develop correlations that capture the variation in homo- and copolymerization propagation rate coefficients with reaction conditions. The investigations are combined to guide the development of a terpolymerization model that includes the formation and consumption of midchain radicals and introduces solvent dependencies for all relevant kinetic mechanisms. The model successfully represents monomer conversion profiles and polymer MMs, branching levels, and copolymer compositions under both batch and industrially-relevant starved-feed semi-batch operating conditions over a broad range of temperatures, monomer contents, solvent compositions and initiator levels. While implemented for MA/AA/t-BuAAm, the model structure can be used to support the development of other acrylate/acrylamide systems as part of the continued efforts to utilize “green” solvents to reduce the environmental impacts of industrial polymerization processes.

abstract: PhD


title: Quantification and Clustering of Microcrack Tensor Invariants

contributor: Geological Sciences and Geological Engineering

subject: Microcrack Invariants

abstract:
In the field of rock mechanics, the behaviour of hard rock materials such as granite are known to depend strongly on the nature of discontinuities present in the material. Even so-called intact rock samples, collected between discontinuities such as joints, often contain microcracks. Microcracks are discontinuities in rock that are measured on the micrometer up to millimeter length scale. A variety of types of microcracks have been observed in granite, the different varieties of microcracks provide insight into the geological origins of rock material, but these distinctions are generally too complex to take into consideration in engineering design. For rock engineering purposes, microcracks can be idealized as circular planar objects in three dimensions, or line segments in two dimensions. As a given rock material is likely to contain many microcracks, the most critical properties of these microcracks are: the density of microcracking, the length of these microcracks, and the orientation of the circular planar objects or line segments.
To predict the behaviour of rock materials, continuum models measure some representative quantity at some representative length scale to characterize that region of rock material, then predictions can be made based on that characterization. This thesis focuses the act of measuring a property that can be useful in modelling hard rock behaviour in continuum models. To take into account the density, size, and orientation of several microcracks in a hard rock material, tensorial quantities have been historically proposed. One challenge with the usage of tensorial quantities in rock engineering is the tedious nature of their measurement. This thesis reduces the cost of measuring microcrack tensors by automating the process through programmatic means, extending previous work which focused on the automatic measurement of scalar properties of microcracks. Due to this programmatic approach, it becomes trivial to measure microcrack tensors as they vary across a thin section image. This thesis also investigates the usage of the invariants of microcrack tensors as features that could be used to differentiate between mineral groups in thin section images, and explains the limitations and possible improvements that could be made with the usage of this feature.

abstract: M.A.Sc.


title: Highly Flexible Yet Hard Transparent Omniphobic Coating Reinforced with an Electrospun Nylon Nanofiber Mat

contributor:
Liu, Guojun
Guojun, Liu
Chemistry

subject:
Flexible
Hard
Transparent
Omniphobic coating
Electrospinning
Electrospun nylon nanofiber
Nanofiber
Composite
Reinforced
Anti-smudge
GPOSS
GPOSS-FC6
nanocomposite
Bendability
wear resistance
abrasion

abstract:
Photocuring GPOSS-g-FC6, 3-glycidyloxypropyl polyhedral oligomeric silsesquioxane (GPOSS) bearing a grafted (g) tridecafluoroheptanoyl group (FC6), produces a transparent omniphobic coating with the highest 9H pencil hardness. Although this coating on a poly(ethylene terephthalate) (PET) film can undergo inward bending to a curvature radius < 1 mm, it has limited bendability on the outer surface of a bending PET film, which limits the application of this coating on the touchscreen of foldable smartphones. My thesis research is aimed at solving this bendability challenge, by reinforcing a GPOSS-g-FC6 coating with a nylon 6,6 electrospun nanofiber mat.
To produce a transparent nanocomposite sample, the electrospun nanofiber diameter must be sufficiently small for minimum light scattering. Thus, the commercial nylon 6,6 was fractionated to yield a higher molecular weight nylon 6,6 (108 ± 4kDa) that enables the production of smaller electrospun nanofibers. The fractionated sample molecular weight was determined via viscosity analysis.
To simplify the preparation of a GPOSS-g-FC6/PET bilayer, electrospinning was done on an ITO-coated PET film. After optimization, a voltage of 20.0 kV, nozzle-to-collector distance of 18.0 cm, a 7.0 wt% nylon 6,6 in formic acid solution, and syringe pump rate of 0.254 mL/h, were used to fabricate nanofiber mats.
GPOSS-g-FC6 was mixed with a photoinitiator to form infusion solutions depending on different thicknesses, and % infusions (by voids volume) of nanofiber mats. A series of nanocomposite samples with 100%, 150%, and 200% infusions at 20, 30, and 40 μm were prepared.
The nanocomposite sample was investigated for its transparency, nanoindentation, pencil hardness, static contact angles, dynamic de-wettability, and wear resistance. The study shows 20 μm 150% infused sample has the best transparency at 98.1 ± 1.1 %. The sample has comparable nanoindentation properties with pure GPOSS-FC6 coating on ITO-PET film, and pencil hardness between 5H and 6H. Nanocomposites with 150% and 200% infusion have comparable de-wetting properties with pure GPOSS-FC6. Higher % infusion and thicker samples have better wear resistance. The free-standing nanocomposites are bendable on both surfaces on the smallest 2.00 mm diameter mandrel in a bend tester. In addition, the nanocomposite retains its ink contraction property after 500 bending cycles.

abstract: M.A.Sc.


title: Psychological Mechanisms Associated with Depression Symptoms and Help-Seeking Intentions Related to Adolescent Dating Violence

subject:
adolescent dating violence
dating volence
disclosure of dating violence
blame attribution

abstract: Adolescent dating violence victimization is associated with negative mental and physical health problems including depression (Barter & Stanley, 2016; Exner-Cortens et al., 2017). Many adolescents do not seek help when victimized by their romantic partners (Bundock et al., 2020). The current thesis comprised two research studies that examined how psychological mechanisms were associated with depression symptoms and help-seeking intentions for adolescents victimized by dating violence. Study 1 was guided by Attribution Theory (Kelley, 1987) and examined the role of blame attributions in dating violence. I found that adolescent girls who attributed blame to victimized individuals experienced higher levels of depression symptoms when victimized. Blame attributions may represent an important process in internalizing dating violence victimization and may reflect general psychological vulnerability. Study 2 examined attitudes and beliefs associated with help-seeking intentions. I found that positive attitudes about the expected outcomes of help-seeking were associated with help-seeking intentions for victimized adolescents. Among help-seeking sources, friends were the most frequently sought out for help. This research demonstrated that psychological mechanisms such as attributions, attitudes, and beliefs are associated with both the interpretation of dating violence and help-seeking intentions. The results have important implications for adolescent dating violence prevention and intervention programs.

abstract: M.Sc.


title: Self reported incompetence

contributor:
Skillicorn, David
Computing

subject:
Machine learning
Transparency
Explainable AI
Uncertainty
Bias
Impact

abstract: Today, machine learning plays an important role in many industries. In order for trust to be established between machine learning predictors and their users, it is necessary to increase transparency and make it easy for anyone to determine a predictor's potential issues. In this thesis, I propose that the predictors themselves could notify the users on their ineptitudes, and closely examine three possible avenues of how to accomplish that: accounting for the effects of uncertainty, determining bias, and detecting potentially impactful predictions. I provide concrete definitions for these concepts, discuss their potential effects on predictive performance, and describe my experiments showing the effectiveness of their use. I find that uncertainty can benefit predictors, but its effect depends on the distribution and which attributes are uncertain. Different sources of bias can be detected without difficulty with the generation of learning curves, confusion matrices, and the comparison of Shapley values for specific attribute values. Finally, my results indicate that detecting potentially impactful or interesting data records can be straightforward by calculating surprise scores, a novel method I propose.

abstract: M.Sc.


title: SILVER NANOWIRE-BASED WEARABLE DEVICES FOR PHYSIOLOGICAL SENSING

contributor:
Lai, Yongjun
Mechanical and Materials Engineering

subject:
Glaucoma
ECG
wearable devices
flexible electronics
medical device
contact lens
silver nanowires
nanoparticles
nanomaterials
PDMS
strain gauge

abstract:
Stretchable electronics are a technology that has allowed for the creation of new wearable devices for the non-invasive collection of physiological data for healthcare monitoring. Nanomaterial enabled stretchable electronics are one class of stretchable electronic materials. These are composite materials consisting of a stretchable a flexible matrix, usually a polymer, and a conductive nanoparticle, like metallic nanowires, graphene, or carbon nanotubes. Challenges exist when it comes to integrating wearable devices based on stretchable electronics with existing rigid technology, with the manufacturing considerations needed to repeatably and reliably couple the flexible matrix with the conductive nanomaterial, and with taking steps to optimize designs to improve the sensitivity of devices.
	In this work, contributions are made towards addressing these challenges that exist in the field of stretchable electronics enabled wearable devices. Specifically, the following contributions are made. 1) An electrocardiogram sensor that is self-adhering and integrates with current technologies is demonstrated. 2) A mould-based method for repeatably and reliably patterning silver nanowires (AgNWs) on polydimethylsiloxane (PDMS) is demonstrated in 2-dimensions. 3) The mould-based technique is extended to allow for patterning AgNWs on curved surfaces, in addition to flat 2-dimensional surfaces. 4) A novel design for a wearable contact lens that can detect intraocular pressure for the purpose of glaucoma detection is demonstrated. 5) The sensor design is improved by changing from a traditional contact lens to a ring-shaped contact lens. 6) The quantification of the changes to transparency and Young’s modulus of PDMS when a laser cutter is used on the material.

abstract: PhD


title: Contaminants of Emerging Concern Treatment by Microalgae: The Status and Future of Phycoremediation

contributor:
Champagne, Pascale
Petkovich, Martin
Civil Engineering

subject:
Microalgae
Cytochrome p450
Wastewater
Emerging contaminant

abstract:
Chemicals of emerging concern (CECs) including pharmaceutical and personal care products are being discharged into aquatic environments at rates causing downstream ecological damage. The removal of these CECs by traditional wastewater treatment plants is insufficient given these facilities were mainly designed prior to the advent of analytical capacities that detect these contaminants at their microtitre concentrations. As sustainable alternatives to wastewater treatment are being considered and developed, these novel technologies must address the traditional demands of wastewater treatment as well as the new challenges posed by CECs. Research has highlighted microalgae as an ideal class of organisms to meet the new challenges in wastewater remediation. Their light-driven metabolism of the primary constituents of wastewater, namely dissolved organic, nitrogenous, and phosphorous material, is well-documented, as is their potential re-use as biofuels, nutraceuticals, or as fertilizers. The opportunities to treat CECs using microalgae is a new research field spanning the past decade, and literature-reported conclusions about their potential is promising.
This thesis summarizes and expands on the current understanding of microalgal-mediated CEC treatment. CECs considered in this text include those from the following classes: antibiotics, antifungal/antimicrobial agents, nonsteroidal anti-inflammatory drugs, anticonvulsants & antidepressants, artificial sweeteners, beta-adrenoceptor blocking agents, lipid regulating drugs, endocrine-disrupting chemicals,  X-ray contrast media, UV filters, stimulants, anti-itching drugs, insect repellents, and plasticizers. The first section presents a meta-analysis of the reported treatment of CECs by eukaryotic and prokaryotic microalgae. This analysis highlights the phylogenetic trends in CEC treatment as well as the chemical and biological effects that drive the primary mechanisms of CEC removal. The second section of this thesis proposes a new avenue of microalgae-mediated CEC treatment through genetic modification. In the form of a review article, this section outlines the potential to heterologously express cytochrome P450 enzymes, primarily responsible for human drug metabolism, to amplify the capacity for microalgae to treat CECs. Considerations regarding enzyme selection, microalgal expression, and potential hindrances to this technology are discussed, serving as a theoretical basis for future experimental validation. Finally, the third section encompasses the preliminary research conducted in the Beaty Water Research Centre. Experiments investigating the capacity to improve CEC treatment using different biological (natural and synthetic) interventions are described and initial results are discussed. The document broadly addresses the past and potential future of microalgal CEC treatment and may serve as a guiding document for future researchers.

abstract: PhD


title: Prevalence and Associations of Work Stress and Llfe Stress with Depressive Symptoms among Female Hospital Day Workers and Shift Workers

contributor:
Aronson, Kristan
Tranmer, Joan
Public Health Sciences

subject:
Depressive symptoms
Work Stress
Life Stress
Healthcare
Female
Shift Work

abstract:
Background: Women working in healthcare experience higher levels of work stress compared to the general population. Life stress may also be higher among this population due to how the nature of the job affects workers’ personal lives. Depressive symptoms and depression are also generally higher among female healthcare workers compared to the general population.
Objectives: To determine the prevalence of work stress, life stress, and depressive symptoms among female hospital employees and their associations among shift workers and day workers.
Methods: A cross-sectional study was conducted at Kingston Health Sciences Centre in Southeastern Ontario between 2011 and 2014 with 168 rotating shift workers and 160 day workers. Levels of work stress were measured using the Job Content Questionnaire and the Siegrist Effort-Reward ratio, life stress was measured using the Derogatis Stress Profile, and depressive symptoms were measured with the Center for Epidemiological Studies Depression Scale. Logistic regression examined associations separately for day and shift workers.
Results: Compared to day workers, shift workers experienced higher levels of psychological job demands (p<0.01), physical exertion (p<0.01), and effort spent (p<0.01) on average, and lower levels of overall support at work (p<0.01). Day workers experienced higher job insecurity (p<0.01), over-commitment (p=0.01) and life stress (p=0.03). The prevalence of moderate to severe depressive symptoms was 27% among day workers and 19% among shift workers. Perceived support resulted in reduced prevalence of depressive symptoms (OR 0.74, 95%CI 0.64 to 0.85) among day workers, whereas perceived job insecurity was associated with higher risk of depressive symptoms (OR 1.39, 95%CI 1.06 to 1.83). Over-commitment was associated with higher prevalence of depressive symptoms (day: OR 1.12, 95%CI 1.00 to 1.26; shift: OR 1.18, 95% CI 1.01 to 1.38), whereas higher esteem was associated with lower prevalence of depressive symptoms (day: OR 0.85, 95%CI 0.77 to 0.94; shift: OR 0.87, 95%CI 0.77 to 0.98).
Conclusions: Prevalence of depressive symptoms was like that seen in previous studies of female healthcare professionals. Although work status  did not meet the statistical criteria as an effect modifier in the association between stress measures and moderate to severe depressive symptoms, some differences were apparent.

abstract: M.Sc.


title: NeuroYara: Learning to Rank for Yara Rules Generation through Deep Language Modeling & Discriminative N-gram Encoding

contributor:
Ding, Steven
Computing

subject:
Deep Learning
Malware Analysis
Malware Detection
Yara Rules
Discriminative Encoding
Language Modeling
Automatic Signatures Generation
Adversarial Malware

abstract:
Signature-based malware detection methods are simple, explainable, and efficient. One of the most ubiquitous tools is Yara. It is a widely-used syntax for writing malware signatures. Compared to machine learning models, Yara rules have a lower false-positive rate and better maintainability of the rules to incorporate new variants of malware. To produce a high-quality rule, one will need extensive experience in reverse engineering and malware analysis. However, it is resource- and time-consuming to train an experienced malware analyst. Only a few works have been conducted to automate the generation of high-quality signatures and generally perform worse than manually-generated ones. Moreover, they rely on a huge static and non-inclusive database of hard-coded byte n-grams. This database is used as the reference set for the automated Yara rules generator which aids in reducing the number of false-positive predictions.

Hence, instead of storing a huge non-inclusive database to score byte n-grams, we propose a novel architecture utilizing two learning-to-rank neural networks to understand the underlying effectiveness of and correlations among n-grams extracted for rule construction. This approach provides better flexibility and coverage of possible n-grams while reducing the required storage size for this task from several GBs to only 10MBs. Combining these two models with a hierarchical density-based clustering method allows us to group multiple n-grams into logical conditions as Yara rules of a higher quality. Compared to state-of-the-art tools for automatic Yara rules generation, our experimental results show that our framework, NeuroYara, reduces the resources invested by the human analyst while generating rules with a low false-positive rate outperforming existing tools and rules manually generated by expert malware analysts.

abstract: M.Sc.


title: Characterization of a Putative Molecular Activator of Spreading Depolarization Generated by the Ischemic Brain

contributor:
Andrew, R. David
Bennett, Brian
Neuroscience Studies

subject:
Spreading depolarization
Stroke
Ischemia
Na+/K+-ATPase
Palytoxin
Ouabain
Red blood cells

abstract: Immediately following brain ischemia, failure of the Na+/K+-ATPase leads to a formidable inward cationic current through an unidentified channel which drives spreading depolarization (SD). Recurrent SD events contribute to tissue injury following stroke or traumatic brain injury and therefore worsen clinical outcomes. Unfortunately, the molecular scenario underlying SD initiation and propagation is unknown. Palytoxin (PLTX) is a marine poison that converts the Na+/K+-ATPase into an open, depolarizing channel. Nanomolar concentrations of PLTX induce SD in live brain slices. Therefore, we used this compound to investigate if metabolically stressed gray matter releases an endogenous molecular activator of SD (SDa), which opens the Na+/K+-ATPase in a PLTX-like manner to promote SD. We also examined whether the putative SDa might evoke afferent pain and investigated its possible chemical identity. To this end, we generated a solution containing biomolecules (including the putative SDa) released from rat brain slices undergoing SD due to oxygen-glucose deprivation (OGD) or hyperthermia (Ht). Using an ex vivo hemolysis assay, we first confirmed that PLTX evoked red blood cell (RBC) swelling and lysis in a concentration-dependent manner. We found that Post-SD(OGD) and Post-SD(Ht) fractions also increased swelling and hemolysis, although a very low amount of PLTX priming (0.005–0.02 nM) was required. These results suggest that the putative SDa acts on the Na+/K+-ATPase to disrupt ionic gradients, causing RBC swelling that progresses to hemolysis. Next, we assessed whether Post-SD(OGD) and Post-SD(Ht) fractions induced mechanical or thermal hypersensitivity in mice. The results suggest that the putative SDa does not activate nociceptors during SD to evoke the subsequent migraine pain. Finally, mass spectrometry analysis of brain slices midway through SD or following ischemic stroke identified several possible lipid species associated with SD propagation, one or more of which could be SDa candidates. Overall, our findings further support the concept of metabolically stressed gray matter releasing a putative SDa that initiates and promotes SD propagation, and provides insight into its mechanism of action and possible chemical identity. Ultimately, the isolation and identification of such a compound may yield novel therapeutic targets to reduce SDs and the subsequent tissue damage following ischemic brain injury.

abstract: PhD


title: The Dp16 Mouse Model of Down Syndrome: Phenotypic Characterization and Assessment of the Pro-Cognitive Agent RIV5061

contributor:
Bennett, Brian
Neuroscience Studies

subject:
Alzheimer's disease
Down syndrome
Cognitive impairment
Mouse models
Preclinical

abstract: Although there are many factors which can influence the development of Alzheimer’s disease (AD), the greatest non-genetic and genetic risk factors are aging and Down syndrome (DS), respectively. The Aldh2-/- mouse model is an oxidative stress-based model of age-related cognitive impairment shown to possess behavioural deficits and pathological changes characteristic of both AD and vascular cognitive impairment. Specifically, Aldh2-/- mice have increased amyloid-beta (A-beta) levels in their cerebral microvessels (CMVs), suggestive of cerebral amyloid angiopathy (CAA). To further investigate this, we assessed levels of the A-beta-disposition-related proteins neprilysin and low-density lipoprotein receptor-related protein 1 in the CMVs of male Aldh2-/- mice relative to wild-type. We found no differences in protein expression, indicating that absolute levels of these proteins are unlikely to account for the observed CAA-like pathology in Aldh2-/- mice. Since DS is the greatest genetic risk factor for AD development, we hypothesized that mouse models of DS might provide a useful complement to existing mouse models of AD, especially for the evaluation of novel therapeutics. Therefore, we assessed the effect of the pro-cognitive agent 4-methyl-5-(2-(nitrooxy) ethyl) thiazol-3-ium maleate (RIV5061) on the behavioural, biochemical, electrophysiological, and morphological properties of the Dp(16)1Yey/+ (Dp16) mouse model of DS. RIV5061 has previously shown pro-cognitive and anti-inflammatory effects in several AD mouse models. We found that male and female Dp16 mice, over a broad age range (2–14 months), exhibited few AD-like phenotypic differences compared with their euploid counterparts. Furthermore, after a twelve-week course of treatment with RIV5061, pro-cognitive effects of RIV5061 were not observed in Dp16 mice, nor were there consistent changes in protein biomarkers, hippocampal CA1 dendritic spine density or hippocampal long-term potentiation. There was, however, an anti-inflammatory effect of RIV5061, as evidenced by reduced expression of the astrocytic marker glial fibrillary acidic protein, in male and female Dp16 and euploid mice. Therefore, with respect to the parameters assessed, we conclude that Dp16 mice are not a particularly representative model of AD, and thus may be of limited value for the assessment of novel AD therapeutics. Dp16 mice may still adequately model DS-AD, but this awaits a more complete assessment of the Dp16 phenotype.

abstract: PhD


title: An Integrated Approach to the Solid Waste Management System on Green Turtle Cay, Abaco, The Bahamas

contributor:
Whitelaw, Graham
Environmental Studies

subject: Small Island Developing Nations, Solid Waste Management, Waste, Waste Generation, Waste Reduction, Waste Diversion, Islands, Island Identity, Archipelagoes, Tourism, Systems Thinking

subject: Bahamas

subject: Green Turtle Cay

subject: Abaco

abstract:
Green Turtle Cay (GTC) is an island 3-miles long in The Bahamas with a strong tourism economy that has been negatively impacted from growing volumes of waste produced each year. The primary form of waste disposal on the island is open dump burning which is impacting the environment, community, and economy. The aim of this research was to answer two questions 1) what is the current state of solid waste management on GTC; and 2) how can government, the private sector, non-governmental organizations (NGOs), and community members on the island collectively improve the current solid waste management system (SWMS)? A content analysis of grey literature, survey of residents on GTC, 3) and semi-structured interviews were used to conduct the research. The most significant results indicate that:
•	there are no regulations on integrated SWMS (only waste collection and disposal through landfilling or burning);
•	95% of survey participants indicated concerns about burning waste on the island, and their personal health and wellbeing due to dump smoke;
•	the top three forms of waste produced from one tourism sector were plastics, organics and glass; and
•	two business in the tourism industry indicated waste generation increased by 280.14% and 266.53% between low and peak season.

The output of the research are recommendations for GTC on how to address the crisis of waste on the island by implementing an Integrated Solid Waste Management System (ISWMS) through the development of:

•	an ISWM committee comprised of government, NGOs and the private sector;
•	island specific ‘regulations’ to guide and govern an ISWM plan;
•	a financial business plan for the ISWMS to sustain the system over time;
•	a local and regional ISWM resource and waste diversion guide;
•	a local educational campaign;
•	a phased strategic plan to remediate the dumpsite and construct a formal waste management facility; and
•	a call to action with Central Government to create national ISWM regulations.

My research helped to provide information for Local Government on GTC to submit proposals for a SWMS to Central Government. During the completion of this thesis, the Central Government of The Bahamas identified a contractor to remediate the dumpsite and develop a new waste management facility on GTC.

abstract: M.E.S.


title: Miniaturized Antenna for Satellite Broadband Application

contributor:
Antar, Yahia
Freundorfer, Alois
Electrical and Computer Engineering

subject:
Antenna
Broadband
Circular Polarization
MEDA
High Gain
Cavity Antenna
Frequency Selective Surface
Array
Array Antenna
Mutual Coupling
Dielectric Coating
Satellite Internet
LEO
Planar Antenna
Complementary antenna
Magneto-Electric Dipole Antenna
Gain Enhancement
Beam Steering

abstract:
User antenna is a crucial component of a high-speed satellite internet system. High directivity, broadband characteristics, and circularly polarized radiations are essential for a user antenna to maintain a reliable connection with the overhead LEO satellite constellation. For commercialization and portability, the antenna is preferred to be planar, lightweight, and low-cost.
This thesis expands on a type of complementary antenna, designed for 26-30 GHz, which is chosen for the application after an extensive survey of wideband, circularly polarized antenna elements. The magneto-electric dipole antenna or MEDA is a broadband antenna and can be made linearly or circularly polarized depending on the application. Although MEDA also offers a stable gain of 8.5 dBi over the desired range of frequencies, yet it is not high enough for the satellite internet application. Cavity antennas with different types of superstrates are explored here to increase the directivity of the MEDA element. An optimized cavity antenna is presented, with MEDA as a primary radiator, and 5.5 dBi of gain enhancement is reported.
Electrical steerability is essential for a user antenna to connect to the LEO satellite constellation, requiring an array of antennas. An array is also needed to increase the total gain of the antenna. However, due to the large size of MEDA, the antenna element cannot be arranged in a planar lattice without generating grating lobes. A novel dielectric material with relative permittivity of 5.7 is coated on the MEDA to significantly reduce the size of the antenna without disrupting its broadband characteristics, to make the MEDA compatible with planar array configuration. The miniaturized antenna element is fabricated in an external facility, whereas the dielectric material is developed in-house. Simulations were conducted with ANSYS EDT (HFSS), which agree with the measured results.

abstract: M.A.Sc.


title: Tort Law, Crown Liability, and the Rule of Law

contributor:
Walters, Mark
Law

subject:
Rule of law
Crown liability
Torts

abstract:
In this thesis, I examine the connection between tort litigation against government and the rule of law principle. I argue that tort claims against government have unavoidable rule of law implications. Since all such tort claims necessarily allege that the government has breached the law, and as tort claims themselves are governed by a legal (judicial) process, the rule of law is necessarily implicated in all tort lawsuits against government.

My project has both a conceptual and a normative dimension. Conceptually, I unpack the way that the rule of law is understood both theoretically, and as reflected and applied in Canadian constitutional law sources. I maintain that the concept of the rule of law in Canada involves a “formalist” core but with many “substantive” offshoots that are often, but not universally accepted. One of these substantive offshoots is a commitment to a principle, whether under the rule of law or as a separate constitutional principle, that I term the “equal government principle”.

Normatively, I argue that if our government is committed to the rule of law (which may include the equal government principle), there are significant consequences for how government ought to litigate, and orient itself towards, tort claims. First, I argue that the government must adopt an “ideal litigant” approach, seeking to follow the procedural rules and to facilitate, rather than hinder, the just resolution of tort claims. Second, I argue that if our government is committed to the equal government principle, substantive efforts to make tort law more favorable to government than private parties is problematic – whether a matter of unique procedural advantages or statutory limitations of tort liability for government. My conclusion is that there are significant and unacknowledged costs to the rule of law paid when our government(s) do not approach tort litigation appropriately – but whether these costs are worth paying remains a question beyond the scope of this project.

abstract: LL.M.


title: ULIME: Uniformly weighted Local Interpretable Model-agnostic Explanations for Image Classifiers

contributor:
Simpson, Amber
Muise, Christian
Computing

subject:
Interpretability
Computer Vision
Explainability
LIME

abstract:
With the rapid development of complex machine learning models, there is uncertainty on how these models truly work. Their black-box nature restricts experts from evaluating models solely on standard numerical metrics, which may result in a model performing seemingly well on a dataset but for the wrong reasons. It is particularly critical to have transparency in medical image analysis due to the importance those decisions have. This is because health care practitioners are hesitant to trust machines when there is no clear reason for the machine to use the appropriate logical steps for a decision, and most importantly, human life is at stake. Regulatory bodies, such as the U.S. Federal and Drug Administration, have recently started pushing guidelines to make AI medical devices more transparent so that they are safer to use.
To address this challenge, many researchers have proposed interpretability methods to generate explanations for the behavior of machine learning models. One popular interpretability method is Local Interpretable Model-agnostic Explanations (LIME), which can explain any black-box model trained on any type of data. Although LIME is a powerful tool, the explanations generated by it depend on how the hyper-parameters of the algorithm are set. If little care is given to the hyperparameters, the resulting explanations can be meaningless.
In this thesis, we first address the impact of a core component in LIME – weights. The weights impact the quality and variability of explanations generated by LIME.
Since weights are determined by the distance metric, we compare the explanations of LIME for three cases; when weights are calculated using (1) an unnormalized distance metric, (2) a normalized distance metric (LIME authors default), and (3) set uniformly to a value of one. Through theoretical analysis and experimentation with different data sets and models, we demonstrate that using the unnormalized distance metric results in poor explanations, whereas the normalized metric and uniform weights give comparable high-quality explanations. We, therefore, propose ULIME (Uniform LIME), a variant of LIME that forgoes the weighted notion of locality by setting all weights to one. Our motivation behind ULIME is the simplification of the existing LIME algorithm by removing the weighting step, and consequently, removal of the distance metric hyper-parameter that is strongly coupled with explanation quality.
Secondly, we address the impact of superpixelization techniques on explanation intuitiveness – a method used to partition the image for explanation purposes. We develop a domain-specific superpixelization method that aids in generating more intuitive explanations and emphasize our results on two medical imaging datasets. Although LIME can be configured for any type of input and model, for this thesis, we restrict our investigation to image classifiers.
Our contributions aim to improve the current state-of-the-art LIME for image interpretability. We simplify LIME by removing the weighting step, reducing the possibility of error due to the distance hyper-parameter, and introducing the concept of domain-specific superpixelization verified by a radiologist. Taken together, our approach improves the quality of explanations, and, thereby, provides a mechanism for physicians and patients to place greater trust in the results of ML models.

abstract: M.Sc.


title: High-Stakes Testing for Adibashi Students: Colonial Approaches to Education for Indigenous Communities of Bangladesh

contributor:
Quadir, Fahim
Scott, Jill
Davis, Jennifer
Cultural Studies

subject:
Adibashi Indigenous
Bangladesh
Colonialism
Education
Standardized High-Stakes Testing
Internal colonialism
Nationalism
Ethnicity
Discriminations
Exclusion
Domination

abstract:
This dissertation investigates how the standardized, high-stakes testing system operates as a political tool used by Bengali elites to advance a nationalist agenda in education that in effect marginalizes Adibashi/Indigenous groups in Bangladesh. To develop an in-depth understanding, this study relies on a qualitative field research methodology to examine the case of Bangladesh and its Adibashi peoples with a focus on the Chakma and Manipuri communities. In addition to employing personal observation, this research collects relevant information and data from both primary and secondary sources, comprising semi-structured and in-depth interviews with 50 Adibashi participants from the two communities and ten Adibashi and non-Adibashi scholars.
This study finds that the language policy, national curriculum, and testing mechanisms manifest Bengali elites’ nationalist ideologies that function against the educational necessities of Adibashi communities and disadvantage them more than Bengali students, thus reproducing a colonial structure of domination and exploitation for Adibashis.
This research reveals that the medium of instruction and the standardized tests have been used as a major political tool of Bengali elites to promote monoculturalism that reproduces linguistic subjugation for Adibashi communities. It finds that the use of Bangla in all educational practices not only creates learning barriers for Adibashi students, it also stigmatizes their linguistic practices, negatively impacts their linguistic choices, and gradually distances them from their ethno-linguistic identities.
This research also illustrates that the national curriculum propagates the nationalist ideologies of Bengali elites and promotes a homogenization process by coercing Adibashis to accept the Bengalicized knowledge system. The curriculum advances homogenization by valorizing Bengali identity, culture, and knowledge while questioning Adibashi identities and knowledge systems. By controlling Adibashi students’ learning experiences, identities, and social relationships, the testing practices and principles reproduce the colonial consciousness of the Adibashis.
This dissertation research contributes to the study of nationalism, critical education research, and Adibashi studies and enhances our understanding of how Bangladesh’s education system is structured around a nationalist agenda of creating a Bengali nationhood that deliberately treats the Adibashis as “the other.”

abstract: PhD


title: The Role of Formal Education in Advancing the Goal of Reproductive Justice: A Case for Comprehensive Sexual Education in Ontario

contributor:
Burfoot, Annette
Sociology

rights: Attribution-NonCommercial-ShareAlike 3.0 United States

subject:
Reproductive autonomy
Reproductive justice
Education
Sexual health
Ontario
Thematic analysis

abstract:
Equitable access to formal education relating to human development and sexual health is integral in achieving reproductive justice at community and provincial levels. Reproductive justice is an important social goal as it provides a framework within which individuals can exercise autonomy over their reproductive and procreative capacities. These individuals can make informed decisions that align with their own goals and desires, absent of the influence of friends, family, policy, or healthcare workers. Formal education is one of the first introductions to topics of human development and sexual health for young people.
The case of Ontario is unique in that the topic of health and physical education has been in the political landscape for over a decade while the social perspectives of sexual education have remained relatively unchanged. The current research project seeks to evaluate the extent to which formal health and physical education in Ontario promotes the development of reproductive autonomy, with a focus on the potential for generating reproductive justice at the provincial level.
Through a thematic analysis and critical reading of both the elementary and secondary level curricula, it is determined that neither curriculum effectively supports the development of reproductive autonomy. The elementary curriculum includes many references to themes indicating the support of autonomy but is structured in such a way that teachers can interpret the curriculum expectations in multiple ways and parents can remove their children from instruction relating to human development and sexual health. Similarly, the secondary curriculum contains indications of supporting autonomy, but this conclusion cannot be made as only one course of the seven offered at the secondary level is mandatory. As a result, most students will likely not encounter those topics.

abstract: M.A.


title: Improving Rock Pillar Stability Guidelines Through Detailed Numerical Investigation

subject:
Rock Mechanics
Pillar
Pillar Stability
Brittle
Underground
Nuclear Waste Storage
NWMO
Numerical Modelling
RS3
Continuum
FEM
Finite Element
Rock
Geological Engineering
Dilation
DISL
Pillar Stability Guidelines
Stability
Guidelines

abstract: Pillar stability guidelines, for underground construction in rock, have been presented by various authors in the past, based on a combination of empirical (mostly visual) observations from mining applications and simple numerical elastic stress indices or data from continuum plasticity analysis. There have been numerous developments in the past several decades in mechanistic classification (brittle spalling, effective continuum rockmass, structural control) and mechanism-appropriate modelling and design metrics. The design of pillar dimensions and spacing is a key factor in construction projects beyond mining including the engineering for deep geological repositories, hydroelectric power cavern complexes, underground storage, quarrying and other applications. These applications are situated in a variety of rockmass environments and at stress regimes from shallow to deep. In such applications, the geometry of the pillars and surrounding excavations deviates from the classic mine pillar scenario where the traditional pillar stability charts may not be able to accurately capture the behaviour of hard rock pillars. To assess the viability of pillar stability charts, a similar (to historical experiments), more detailed experiment was conducted simulating 3D Hoek-Brown, finite element method (FEM) pillars, with varying rockmass material parameters. From these model simulations, a five-phase pillar failure classification was developed. Using the classification charts developed, refine pillar stability charts. The refined pillar charts indicate that the material parameters used in the modelling can significantly change a pillar’s behaviour and that a single pillar stability chart is likely inadequate for describing the behaviour of mine pillars. The residual behaviour of pillars was also assessed using a correlation developed for determining an estimated residual GSI (and the associated residual strength after yield). The data for the residual pillar data agrees with previous findings that a single chart is inadequate for describing pillar behaviour. Modifying the residual GSI for a pillar can significantly impact the resulting strength predictions for the pillar. Post-yield dilation increases the effective area of the pillar core, increasing pillar stability. Dilation does not have as large of an effect on more slender pillars (< 0.7 W:H ratio) as confinement is lesser on more slender pillars.

abstract: M.A.Sc.