Faculty of Graduate Studies Online Theses
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Item Open Access TRAINING AND EVALUATING THE USE OF LARGE LANGUAGE MODELS (LLMS) IN THE DOMAIN OF CANADIAN NUCLEAR INDUSTRY(2025-07-10) Anwar, Muhammad Saleh; Not Applicable; Master of Science; Department of Engineering Mathematics & Internetworking; Not Applicable; N/A; Not Applicable; Dr. Guy Kember; Dr. Kamal El-Sankary; Dr. Issam HammadThis thesis addresses the challenges of accuracy, reliability, data privacy, and resource constraints in applying Large Language Models (LLMs) to the Canadian nuclear industry. It presents a multi-faceted approach by evaluating existing models, developing synthetic data generation techniques, and training a secure, domain-specific LLM from scratch. The research first demonstrates that while general-purpose LLMs are prone to factual inaccuracies on nuclear-specific topics, their reliability is significantly improved by integrating a Retrieval-Augmented Generation (RAG) framework. This approach enhances factual accuracy by grounding responses in verified, domain-specific documents. To overcome data scarcity and confidentiality barriers, the thesis pioneers a methodology for generating synthetic, structured question-and-answer pairs from unstructured nuclear texts using LLMs. This scalable and privacy-preserving approach creates valuable, model-ready datasets for training and evaluation without exposing sensitive information. Furthermore, the work validates the feasibility of developing a secure, private LLM from scratch. By training a compact model on a single GPU using the "Essential CANDU" textbook, it demonstrates a practical path for creating in-house models that mitigate cybersecurity risks and can learn specialized terminology within a resource-constrained and secure environment. Collectively, this research provides a comprehensive framework for integrating LLM technology safely and effectively into the nuclear industry, establishing a foundation for advanced AI tools that enhance knowledge management and operational support.Item Open Access Model Predictive Control for Autonomous Sailboat with Sail Angle Optimization and Trajectory Planning Under Stochastic Winds(2025-07-14) Wu, Junzhuo; Not Applicable; Master of Applied Science; Department of Mechanical Engineering; Not Applicable; N/A; Not Applicable; Dr. Baafour Nyantekyi-Kwakye; Dr. Hamed Aly; Dr. Ya-Jun Pan; Dr. Chao ShenThis thesis investigates the development and implementation of model predictive control (MPC) frameworks for autonomous sailboat control under different wind conditions. The research is motivated by the need for robust, constraint-aware control strategies for sailboats, that can effectively handle the nonlinear dynamics and environmental uncertainties. The study begins with a comprehensive modelling of sailboat dynamics, incorporating sailboat kinematic and kinetics and wave disturbances. Two simulation-based studies both using MPC are then conducted. The first study focuses on sail angle optimization and trajectory tracking, where the control objective is to maximize sailing speed with safety considerations and then achieve accurate trajectory tracking. The second study addresses stochastic wind sailing, where an NMPC-based path planning and tracking controller is designed and evaluated. This controller integrates the controllability analysis to improve performance under both deterministic and stochastic wind conditions. Comparative simulations highlight the advantages of the proposed approach. Then, an experimental platform is instrumented on a small-scale physical autonomous sailboat. This platform integrates the ArduPilot control stack, hardware components and supporting software infrastructure. System identification techniques are applied to extract sailboat’s dynamic model, and experimental trials are conducted to assess the controller performance in real-world conditions. The results demonstrate that MPC offers a viable and effective solution for autonomous sailboat control, capable of addressing both operational constraints and environmental variability.Item Open Access Beyond Monocular Vision: Assessing LLaVA's Performance on an Augmented CLEVR-like Dataset with Binocular Images(2025-07-07) Devesh, Sagar; Not Applicable; Master of Computer Science; Faculty of Computer Science; Not Applicable; n/a; Not Applicable; Vlado Keselj; Hassan Sajjad; Frank RudziczThis thesis investigates how binocular vision impacts the spatial reasoning capabilities of Large Language and Vision Assistant (LLaVA) models in visual question answering tasks. By developing BiCLEVR, an augmented CLEVR-like dataset featuring stereoscopic image pairs and expanded visual attributes, we systematically evaluate the effect of different visual inputs across varying model sizes. Our experiments compare two LLaVA variants (7B and 13B parameters) across three dataset configurations: standard CLEVR, monocular BiCLEVR, and binocular BiCLEVR. Results reveal a nuanced relationship between model capacity and the ability to leverage stereoscopic information. The larger model demonstrated significant performance improvements with binocular input, while the smaller model showed degraded performance, suggesting insufficient capacity to process the additional visual information effectively. Particularly notable were improvements in numerical comparison and counting tasks for the larger model, indicating that stereoscopic cues enhance object individuation abilities. These findings contribute to our understanding of how vision-language models process spatial information and provide a pathway toward more robust visual reasoning systems capable of understanding 3D relationships in complex environments.Item Embargo Active Removal of Tumbling Orbital Debris Using an Autonomous Chaser Vehicle in the Presence of Perturbations(2025-07-02) Adolph, Mathew; Not Applicable; Master of Applied Science; Department of Mechanical Engineering; Not Applicable; n/a; Not Applicable; Dr. Guy Kember; Dr. Darrel Doman; Dr. Mae SetoTo address and abate the issues related to uncontrolled debris in orbit around Earth, active debris removal (ADR) is imperative. To perform ADR, a chaser satellite is used to rendezvous and capture the debris. Docking with debris is difficult as it is rotating about multiple axes; this is known as tumbling. This thesis details the development of an autonomous flight control strategy that attempts to synchronize and dock with tumbling debris in orbit to facilitate capture. The control strategy employs a model predictive control algorithm to predict the future state of the chaser and debris while simultaneously layering a separate closed-loop attitude controller to orient the chaser towards the debris. The control strategy was shown to successfully dock to debris tumbling at 2.6 deg/s with a 0% failure rate when at an initial separation of less than 25 m from the debris. The chaser was also able to reliably dock in less than 5 minutes to debris tumbling up to 4.5 deg/s when initially positioned 2.45 m from the debris. This research demonstrates that a single control scheme can potentially be used to successfully service a wide variety of candidate debris missions and docking conditions. The control strategy also demonstrates disturbance rejection, including recovery from a simulated micro-asteroid impact. The implemented algorithms were developed to integrate with a planar air-bearing testbed for future validation of the control strategy using hardware.Item Open Access FRONTAL PLANE LANDING MECHANICS AND GLUTEUS MEDIUS MUSCLE ACTIVITY IN INDIVIDUALS RETURNED TO SPORT POST ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION(2025-07-09) Galloway, Ewan; Not Applicable; Master of Science; School of Physiotherapy (Rehabilitation Research); Received; Dr. Christopher MacLean; Not Applicable; Dr. Rebecca Moyer; Dr. Scott Landry; Dr. Derek RutherfordKnee injuries, particularly to the anterior cruciate ligament (ACL), are common and can negatively impact joint health. These injuries often occur during high-impact movements, such as landing from a jump. While jump landings are used in rehabilitation and return-to-sport protocols, current assessments lack sensitivity in identifying individuals at risk. This thesis investigated differences in peak frontal plane projection angle (FPPA) and gluteus medius (GMed) activity during single-leg landings, as well as the relationship between FPPA, GMed activity, and hip abductor strength. Twenty-five individuals post-ACL reconstruction (ACLR) and 25 asymptomatic controls performed single-leg drop landings and maximal voluntary isometric contractions. No significant differences in peak FPPA were found between groups, but the affected limb in the ACLR group showed greater FPPA than the unaffected limb. No group differences were observed in GMed activity. However, lower GMed activity and hip abductor strength were significantly associated with greater FPPA.Item Open Access Enhancing the Monogastric Gut Microbiome Through Innovative Nutritional Strategies(2025-07-05) Lu, Jing; No; Doctor of Philosophy; Department of Animal Sciences and Aquaculture; Received; David Huyben; Yes; Renee Petri; Beth Mason; Vasantha Rupasinghe; Stephanie CollinsThe host and microbiome can be viewed as one integrated system, which highlights the need to optimize nutrition for both the host and its gut microbiome. This thesis explored the use of nutritional strategies as selective forces to support gut microbiome diversity and resilience and ultimately improve host health and adaptability, particularly in those facing loss of host genetic and microbial diversity. Two model species, chickens (Studies 1 and 2) and polar bears (Study 3), were used to investigate gut microbiome modulation from developmental (early life vs. adult stage) to ecological (agriculture vs. conservation) contexts. Study 1 investigated reinforcing deterministic selection during early life to facilitate a lasting gut microbiome modulation through the priority effect in broiler chickens. In ovo delivery of seaweed polyphenols significantly reduced the abundance of a necrotic enteritis-causing genus, Clostridium sensu stricto 1, in the ileum of broiler chickens by day 28 post-hatch, similar to long-term supplementation of in-feed antibiotics. Study 2 examined the role of diet as a strong selection force during the production phase in two commercial strains of laying hens. Dietary inclusion of black soldier fly larvae meal (BSFLM; 0%, 6.5%, and 13%) significantly increased cecal microbial diversity and shifted short-chain fatty acid profiles toward higher acetic acid production. The 13% BSFLM inclusion increased nitrogen and ammonia excretion, which was alleviated by protease supplementation, suggesting that increased microbial diversity may reflect suboptimal protein utilization and proliferation of proteolytic taxa. Study 3 shifted focus to wildlife and compared the fecal microbiome of wild and captive bears to understand the influence of environmental factors. Captive bears had greater fecal microbial diversity, and a distinct community structure compared to wild bears. Individual variation was the main driver of microbial differences among captive bears. Captive bears fed seaweed, a natural dietary item for wild bears, showed minimal change in fecal microbiome. Together, these findings demonstrated the potential of gut microbiome-informed nutritional strategies to promote animal gut microbial resilience across life stages and in both agricultural and conservation settings. Microbial diversity should be interpreted with functionality and interaction with the host to fully understand its implications.Item Open Access Evaluation of Metal Ion-Releasing Glass Particles to Enhance Antibiotic Efficacy Against Cystic Fibrosis Infection(2025-06-30) Wolverton, Maxwell; Not Applicable; Master of Applied Science; School of Biomedical Engineering; Not Applicable; Dr. Mark Filiaggi; Not Applicable; Dr. Daniel Boyd; Dr. Zhenyu Cheng; Dr. Brendan LeungIn cystic fibrosis (CF), thickened airway mucus impairs mucociliary clearance, leading to chronic bacterial infections that cause lung damage and respiratory failure--the leading causes of mortality in CF patients. Although antibiotics are the primary treatment, incomplete bacterial eradication can promote antibiotic resistance. This project investigates whether combining conventional antibiotics with antibacterial metal ions delivered via borate bioactive glass can improve treatment efficacy. An in vitro airway infection model was developed to mimic the CF lung microenvironment using bronchial epithelial cells, a mucus-like hydrogel, and bacteria deposited via an aqueous two-phase system. Bioactive glass formulations demonstrated additive and synergistic antibacterial effects against common CF bacteria when used with antibiotics, without harming epithelial cell viability. These findings suggest that antibiotic-glass combinations may enhance bacterial clearance in CF airway infections and reduce the risk of resistance development, offering a promising therapeutic strategy for CF patients and others vulnerable to persistent lung infections.Item Embargo Data-Driven Design: Leveraging Predictive Modeling for the Development of Soluble and Insoluble Glasses for Medicine(2025-06-25) Kettlewell, Brenna; Not Applicable; Doctor of Philosophy; School of Biomedical Engineering; Not Applicable; Dr. Anthony Wren; Yes; Dr. John Frampton; Dr. Locke Davenport-Huyer; Dr. Mark Glazebrook; Dr. Daniel BoydThe rational design of biomaterials that interact with biological systems to promote healing and regeneration remains a central challenge in medicine. Traditional materials discovery approaches, particularly for bioactive glasses, are limited by trial-and-error methods. This thesis adopts a data-driven approach aligned with the Materials Genome Initiative (MGI) to predict composition-property relationships in both soluble and insoluble glasses for medicine. A systematic investigation of 23 multi-component soluble borate glasses enabled the development of statistical models capable of predicting the individual and interaction effects of glass constituents on structure, dissolution, ion release, and cytocompatibility. In parallel, 16 aluminosilicate glass microsphere formulations were developed for transarterial radioembolization (TARE), optimized for thermal and chemical stability, low cytotoxicity, and compatibility with CT and SPECT imaging. Across both systems, predictive modeling enabled the identification of optimal formulations, demonstrating the power of integrated experimental and computational strategies in advancing bioactive glass design for clinical applications.Item Embargo Groceries Online - Eating, Acquisition, & Technology (GO-EAT)(2025-07-04) Wong, Helen; Not Applicable; Doctor of Philosophy; School of Health Administration; Received; Dr. Sophie Desroches; Yes; Dr. Sara Kirk; Dr. Irena Knezevic; Dr. Leia Minaker; Dr. Catherine MahGrocery shopping is important for healthy eating. Online grocery shopping (OGS) has become popular in Canada, but its impact on diets remains unknown. With a multi-methods approach informed by the Theory of Planned Behaviour, this thesis by manuscript examined how OGS, and digital touchpoint usage (any instances when a consumer interacts directly or indirectly online with a brand, company, or business) in grocery routines, contributed to food-related purchasing decisions and diets. Healthcare professionals who were 18-64 years old and OGS consumers were recruited in Nova Scotia. Interviews were conducted with ten participants and in-depth behavioural questionnaires were administered over a 28-day study period to seven participants. This thesis identified ‘how’ (i.e., behaviours) participants shopped online for groceries and used digital touchpoints, but also the ‘why’ (i.e., beliefs) behind their behaviours. Findings support the importance of considering individuals as free agents and key implications for environmental restructuring in healthy eating behaviours.Item Open Access THE EFFECT OF GROUND MOTION UNCERTAINTY ON THE SEISMIC RELIABILITY OF GEOTECHNICAL SYSTEMS(2025-07-04) Esposito, Gennaro; No; Doctor of Philosophy; Department of Engineering Mathematics & Internetworking; Not Applicable; Dr. Luc Choiunard; Not Applicable; Dr. Craig Lake; Dr. Farzane Naghibi; Dr. Gordon FentonThe ground motion variability is typically not included in earthquake design. The main goal of this research was to quantify the effect of the ground motion intensity variability on the seismic reliability of geotechnical systems. This is to calibrate the seismic design of geotechnical systems included in codes and to assess if the standard of practice is adequate to estimate the seismic resiliency of geotechnical systems not regulated by design codes. Due to the complexity of the problem, a simplified probabilistic model was developed, which is based on the execution of few numerical analyses and the use of simple functions correlating the random variables of the problem. The simplified probabilistic model still requires numerical integration, however integration can be performed using commercial spreadsheets. The simplified probabilistic model overcomes the distinction between epistemic and aleatoric uncertainty. It is believed that this distinction is not real and that the total estimated variability of the ground motion is necessary for design and performance assessment. The simplified probabilistic model was applied to three problems described below. For the problems where no target performance is available, target reliability indexes were proposed based on available literature and engineering judgement. First, geotechnical resistance factors were determined for single piles subject to vertical and horizontal seismic loads. The results of the calibration produced geotechnical resistance factors which are smaller than those indicated in the Canadian Highway Bridge Design Code (2019). During this effort, an algebraic approximate solution of the probabilistic model was developed. The algebraic expression can be used to check future calibration executed using either the simplified probabilistic model or more complex methodologies. It was found that, when considering different sites having the same load and soil distributions, the calculated probability of failure depends on the local ground motion hazard. As a consequence, to achieve the same reliability level at different sites, either different geotechnical resistance factor for different seismic regions should be selected, or the national ground motion hazard should be adjusted to achieve a uniform risk level. The author of this research believes that the second approach is the only one able to achieve similar levels of geotechnical risk throughout Canada. Second, the effect of the ground motion variability on the probability of failure of tailing dams was assessed using the same simplified probabilistic model used for the pile problem. There is no official dam “design code” in Canada. The design standard used in practice is the Canadian Dam Association Manual (CDA, 2013), which is in reality a code as it is referred to by provincial regulation of Canada. The performance targets given by CDA (2013) are in terms of loss of life, which are conditional on the occurrence of a dam seismic failure. As result, an accurate estimation of the dam probability of seismic failure is essential. It was found that the inclusion of the ground motion variability has a profound impact on the calculated probability of failure and on the dam classification and as such it should be always included in the calculation of the probability of failure. The third problem investigated in this research concerns how the ground motion uncertainty affects the calculated probability of damage caused by induced seismicity in an area located in the northeast of British Columbia. The simplified probabilistic model was applied to this problem, including a conditional probability of failure related to structural damage. Since damage states and associated acceptable reliability levels for these problems are not defined, reliability indexes were derived from existing codes or literature and proposed for the area. In addition, a probabilistic seismic hazard model was developed to describe the non-Poissonian nature of the problem.Item Embargo TAILORING EXERCISE FOR ADVANCED PANCREATIC CANCER CARE: UNDERSTANDING AND INTEGRATING THE PATIENT PERSPECTIVE(2025-07-02) Cyr, Chloe; No; Master of Science; School of Health & Human Performance; Received; Robin Urquhart; Yes; Ravi Ramjeesingh; Chris Blanchard; Melanie KeatsPancreatic cancer is associated with poor prognosis and high symptom burden. Although exercise is well-known to improve quality of life and mitigate adverse outcomes in cancer care, exercise programming in advanced pancreatic cancer care remains limited. This thesis used a pragmatic qualitative interpretive description approach to explore the exercise experiences and perspectives of individuals living with advanced pancreatic cancer in Canada. Six individuals diagnosed with stage III/IV exocrine pancreatic cancer from across Canada were interviewed and a reflexive thematic analysis was conducted. Three themes were identified impacting how exercise was perceived and experienced: (1) Taking control of my journey; (2) Building the motivation; and (3) A program for me. Connections to the Behaviour Change Wheel and Theoretical Domains Framework were identified and explored within each theme. Findings from this study will be integrated within an exploratory sequential mixed methods project to co-create and implement a tailored exercise program for advanced pancreatic cancer care in Canada.Item Open Access The Impact of Frailty on Fitness Gains from an Exercise Oncology Program(2025-07-02) Pedrick, Denelle; No; Master of Science; School of Health & Human Performance; Not Applicable; Dr. Myles O'Brien; Not Applicable; Dr. Melanie Keats; Dr. Stefan Heinze; Dr. Scott GrandyThis study examined the impact of frailty on fitness gains among individuals living with and beyond cancer who participated in a 12-week multimodal exercise oncology program (ACCESS). Using secondary data from a sample with a mean age of 59.8 years (SD= 11.6), participants were classified as frail or non-frail based on Frailty Index scores derived from the Pictorial Fit-Frail Scale. Physical fitness outcomes—including walking distance, muscular endurance, grip strength, and balance—were assessed pre- and post-intervention. Participants were also stratified by age (<65 vs. ≥65) to explore age-related effects. Correlational analyses and repeated measures ANOVA were conducted. Findings revealed that frailty was weakly associated with reduced improvements in aerobic and muscular endurance, particularly among older adults. However, frail individuals still demonstrated meaningful gains, and frailty did not significantly limit improvements over time. These results suggest that structured exercise programs can benefit frail individuals living with and beyond cancer, reinforcing the value of inclusive exercise interventions and the need for tailored approaches in oncological rehabilitation.Item Embargo HYPOXIA MEDIATES N-METHYL-D-ASPARTATE SIGNALING RELATED SUSCEPTIBILITY TO TRAUMATIC BRAIN INJURY(2025-07-02) Muradov, Jamil; Not Applicable; Doctor of Philosophy; Department of Medical Neuroscience; Received; Jamie Hutchison; Yes; Lutz Weise; William Baldridge; Alon FriedmanCortical spreading depolarizations (CSDs) are an early hallmark of traumatic brain injury (TBI) and are associated with poor clinical outcomes, yet their underlying mechanisms remain poorly understood. We hypothesized that post-traumatic hypoxia promotes CSDs and impairs neurovascular responses. This study examined how hypoxia and CSDs affect neurobehavioral outcomes post-TBI and evaluated the effects of NMDAR antagonists as potential therapeutics. Using an animal model of single moderate TBI (N=67), we assessed its outcome variability (Chapter 2). TBI impaired neurological scores at 48 h post-impact (p<0.0001) and disrupted the neurovascular response to CSDs. Behavioral scores showed a bimodal distribution (R²=0.88; trough=7.01), categorizing animals into “susceptible” and “resilient” groups. Susceptible animals exhibited early cardiorespiratory dysfunction (lower HR and SpO₂ at hind paw and neck; p=0.02, p<0.001, p=0.01) and a significantly reduced neurovascular response to triggered CSDs, along with prolonged post-CSD oligemia. To explore the relationship between hypoxia and CSDs (Chapter 3), I used epidural electrodes and cranial window surgery. Animals that developed CSDs had lower mean SpO₂ (83.6%) compared to those that did not (92.2%). The co-occurrence of CSDs and hypoxia significantly altered the neurovascular response, with a 16% reduction in cerebral blood flow during the expected hyperemic phase, suggesting potential hypoperfusion and ischemia. In Chapter 4, I studied CSD-induced vascular responses in resilient vs. susceptible animals under hypoxia or following NMDAR antagonist treatment. Memantine reduced CSD incidence by 42–73% and mitigated cortical hypoperfusion. In a randomized pre- clinical trial, memantine treatment improved behavioral outcomes and preserved neurovascular function. This multi-modal investigation identified post-impact hypoxia as a key driver of CSDs and demonstrated that hypoxia and CSDs synergistically impair neurovascular regulation. Targeting these processes through oxygen support and NMDAR antagonism prevented secondary injury and improved outcomes. These findings may inform mechanism-based strategies for mitigating TBI susceptibility across injury severities.Item Open Access Assessing The Associations Between Asbestos Exposure and Breast Cancer Incidence Among Nova Scotian Females in a Longitudinal Cohort Study(2025-06-26) Ring, Ethan; Not Applicable; Master of Science; Department of Community Health & Epidemiology; Not Applicable; n/a; Not Applicable; Dr. Ellen Sweeney; Dr. Nathalie St-Jacques; Dr. Cindy Feng; Dr. Robin UrquhartBreast cancer is common among female populations worldwide. While many risk factors for breast cancer are well-established, potential associations between asbestos exposure and breast cancer incidence remains a subject of ongoing investigation. This population-based study utilized data from 8,808 cancer-free females in Nova Scotia. Multivariable logistic regression was used to assess associations between three binary indicators of asbestos exposure (at work, at home and overall) and breast cancer incidence, adjusting for various confounders. Increased odds of breast cancer among participants reporting prior asbestos exposure in the workplace was noted (AOR = 1.75, 95% CI: 1.00 – 3.06). Elevated risks were observed for following occupational asbestos exposure (AOR = 2.18, 95% CI: 1.21 – 3.92) and overall asbestos exposure (AOR = 1.82, 95% CI: 1.06 – 3.11) among females 50 years of age or older. These results warrant further investigation to uncover potential biological mechanisms and confirm observations among other populations.Item Embargo Assessment of Functional Recovery in Experimental Autoimmune Encephalomyelitis by Putative Remyelinating Drugs(2025-06-24) Kasheke, Gracious; Yes; Doctor of Philosophy; Department of Pharmacology; Received; Dr. Jack Antel; Yes; Dr. Patrice Côté; Dr. Corey Baimel; Dr. George RobertsonCurrent immune-based therapies for multiple sclerosis (MS) reduce disease relapses but have limited value in slowing disease progression. Remyelination in the central nervous system (CNS) is considered essential for functional recovery in MS. This has driven an intense search for drugs that promote myelin repair. This thesis compared the efficacy of four putative remyelinating drugs at promoting motor recovery in a mouse model of MS termed experimental autoimmune encephalomyelitis (EAE). EAE recapitulates many pathophysiological features of MS including autoimmune mediated demyelination and axonal damage. Furthermore, we have shown that EAE produces MS-like gait deficits in mice. Kinematic gait analysis was therefore employed to identify drugs that promote functional recovery in EAE mice. To this end, we compared the effects of oral administration of pioglitazone, VP3.15, olesoxime, or IRX4204 beginning at peak disease on EAE-induced gait deficits. Unlike pioglitazone, VP3.15, and olesoxime, IRX4204 reduced clinical scores, loss of knee average angle, and elevation of knee and ankle RMS differences. These gait improvements in IRX4204-treated EAE mice were associated with transcriptional and histological signs of reduced inflammation, increased remyelination, and enhanced axonal integrity in the spinal cord. Experimentation with a mouse microglial cell line and primary astrocyte cultures showed that IRX4204 suppressed the expression of pro-inflammatory cytokines induced by treatment with lipopolysaccharide. IRX4204 also enhanced mitochondrial function and the phagocytotic activity of microglia. These findings support the potential of IRX4204 to increase functional recovery in MS by stimulating myelin repair. However, IRX4204 suffers from poor CNS uptake and adverse side effects caused by actions on cells outside of the CNS. To overcome these problems, we developed an intranasal nanoparticle formulation of IRX4204 designed to preferentially deliver this drug to the CNS. Our findings suggest that intranasal nanoparticle delivery is a promising strategy to improve the safety and efficacy of IRX4204 but also reveal limitations of this approach.Item Open Access Understanding the global and local evidence on the process of student engagement in Health Promoting Schools(2025-06-23) Kontak, Julia; Yes; Doctor of Philosophy; Faculty of Health; Received; Dr. Antony Card; Yes; Dr. Camille Hancock-Friesen; Dr. Becky Feicht; Dr. Sara KirkHealth Promoting Schools (HPS) is a whole-school approach that facilitates environments for student health and learning. Despite evidence supporting outcomes of student engagement, a key component of HPS, little is known regarding process factors that lead to these benefits. In Nova Scotia, Canada, UpLift (2019 – 2024), a school-community-university partnership was formed to catalyze HPS, with a focus on student engagement. To amplify student engagement, Youth Engagement Coordinators (YECs) were hired, and Student Action Grants were established. The aim of this dissertation was to understand the process of student engagement in HPS at the global and local level. First, a scoping review was conducted to globally map and characterize the process of student engagement in HPS. Of the 50 sources analyzed, process factors related to participatory mechanisms for engagement included reflection and visioning, co-determining priorities and action-oriented learning. Second, a co-design approach using a transformative lens was employed to understand perspectives from students (n = 9, grades 7 - 11) and YECs (n = 6) involved in UpLift. This involved two co-design workshops where participants worked with the research team to gather, analyze, and interpret the data. Methods with students involved the draw, write and tell method, and a participatory focus group. Methods with YECs included a focus group, participatory mapping and a theming exercise. Following the workshops, reflexive thematic analysis was employed, and member reflection was conducted. Findings from the student group outlined the significance of strategies to build motivation for action, a collaborative space for youth, and adult facilitation practices. Findings from the YECs emphasized the importance of reflexivity, school culture, connections with school members, expansion on the concept of health and equitable environments for youth voice. This dissertation provides global and contextual considerations specific to Nova Scotia on the process for student engagement in HPS. Findings highlight factors across the process spectrum, from foundational considerations including adult positioning and school culture, to more specific implementation strategies related to collaborative decision-making. Findings highlight the relationship between student health promotion competencies and youth agency. These findings will directly build the knowledge base and contribute to local student engagement efforts in HPS.Item Embargo Bathymetric Anomaly Detection Towards Simultaneous Localization and Mapping on Autonomous Underwater Vehicles(2025-06-23) Cain, Nolan; Not Applicable; Master of Applied Science; Department of Mechanical Engineering; Not Applicable; na; Not Applicable; Dr. Ted Hubbard; Dr. Guy Kember; Dr. Mae Seto; Dr. Robert BauerAutonomous underwater vehicles (AUVs) are uncrewed vehicles that can dive to deep depths or under ice to map the seafloor in the Arctic. Due to the lack of global navigation satellite systems (GNSS) underwater, AUV's rely on inertial navigation to estimate their position. Inertial navigation suffers from unbounded error drift. Simultaneous localization and mapping (SLAM) can be used to correct the AUV's positional estimate by repeatedly observing landmarks in its surrounding terrain. Bathymetry has been used to define landmarks for underwater navigation using feature extraction techniques designed for optical imagery. This thesis describes the development of a novel anomaly detector, `Bathymetric Anomalies from Anti-Motifs' (BAAM), that is purpose-built to detect unique bathymetric landmarks. BAAM exploits known bathymetric motifs (commonly repeated patterns) to detect bathymetric anomalies which can be used as landmarks for SLAM. Bathymetric motifs were extracted from a region of Delaware Bay bathymetry using a 2-D adapted matrix profile algorithm, geometric transformation- and scale-invariant image matrix profile (GTSI-IMP), that was developed in this thesis. The ability to associate landmarks, of BAAM and existing optical feature extraction algorithms, was evaluated using semi-synthetic sonar images of a separate region of Delaware Bay bathymetry. For the conditions used in this research, the BAAM detector combined with the binary robust invariant scalable keypoints (BRISK) descriptor produced more correct matches than many of the optical feature extraction methods. However, the scale-invariant feature transform (SIFT) detector combined with the BRISK descriptor was found to produce the most correct matches in both the noise-free and noisy semi-synthetic sonar images. Despite SIFT-BRISK's ability to produce more correct matches than BAAM-BRISK on these semi-synthetic sonar images, the landmarks identified in the Delaware Bay bathymetry using BAAM were found to be more unique (anomalous) than those identified using SIFT.Item Embargo Synthesis of Phosphino(Silyl) Ligated Nickel and Manganese Complexes for the Catalytic Hydrofunctionalization of Alkenes(2025-06-17) Saunders, Tyler; Not Applicable; Doctor of Philosophy; Department of Chemistry; Not Applicable; Johanna Blacquiere; Yes; Mark Stradiotto; Saurabh Chitnis; Norman Schepp; Laura TurculetTransition metal catalysts play a key role in the synthesis of value-added products from abundant raw materials. While homogeneous catalysts that feature scarce metals such as Pd, Pt, Rh, and Ru have proven effective, recent focus on sustainability has led to interest in utilizing Earth-abundant 3d-metals such as Mn, Fe, Co, and Ni. Multidentate phosphino(silyl) ligands under investigation in the Turculet group have proven useful in 3d-metal mediated catalysis. This document details the development of new tridentate PSiN and bidentate PSi supported Ni and Mn complexes for application in hydrofunctionalization catalysis. Nickel complexes supported by a new PSiN ligand that features a quinolyl donor, as well as complexes supported by the bidentate CyPSi (CyPSi = κ2-(2-Cy2PC6H4)SiiPr2) ligand were shown to be effective pre-catalysts for alkene tandem isomerization-hydroboration. Deuterium labeling experiments support a Ni-mediated alkene chain-walking mechanism involving reversible alkene insertion/β-hydride elimination. Borylation occurs exclusively at a terminal position, affording high selectivity. Nickel complexes supported by a new PSiInd ligand featuring an indolyl backbone were also pursued, and these complexes along with (CyPSi)Ni species were screened in alkene hydrogenation catalysis. A variety of sterically hindered, unfunctionalized alkenes were readily hydrogenated under mild conditions. Deuteration experiments highlight the occurrence of background chain-walking, similar to that observed in the previous hydroboration studies. The synthesis of chiral phosphino(silyl) Ni complexes for application in asymmetric catalysis was also targeted. In this regard, a new (BIPHEN-SilaPhos)Ni(η3-C8H13) complex is described. This complex and the previously synthesized ((S,S)-TADDOL-SilaPhos)Ni(η3-C8H13) were applied in the asymmetric hydrogenation of (Z)-2-acetamido-3-arylacrylates to access chiral α-amino acid esters. SilaPhos ligation represents a new approach to chiral ligands featuring chirality at a Si donor. The (S,S)-TADDOL-SilaPhos ligated Ni complex afforded the desired products in near quantitative yields with excellent enantioselectivity (up to 98:2 er). Both direct and transfer hydrogenation with iPrOH as the hydrogen source are shown to be viable pathways for this reactivity. Progress towards the synthesis of Mn complexes supported by multidentate phosphino(silyl) ligation is also described. Mn(I) tricarbonyl complexes supported by CyPSiP (CyPSiP = κ3-(2-Cy2PC6H4)2SiMe) and PSiN ligation were synthesized and structurally characterized. The utility of Mn pre-catalysts in alkyne semi-hydrogenation and alkene hydrogenation was investigated. In situ generated Mn(II) dialkyl complexes featuring CyPSiP and PSiN ligation are shown to be active in the catalytic hydrogenation of a range of terminal alkenes.Item Open Access Optogenetic-Based Models of Arrhythmia-Induced Cardiomyopathy in Larval Zebrafish(2025-06-19) Savoie, Emma; Not Applicable; Master of Science; Department of Physiology & Biophysics; Not Applicable; Keith Brunt; Not Applicable; Thomas Pulinilkunnil; Ketul Chaudhary; Alexander QuinnArrhythmia-induced cardiomyopathy (AiCM) has recently emerged as a distinct subset of cardiomyopathy, resulting from chronic tachycardia or high ectopic burden, which leads to structural and functional changes in the heart. Traditional experimental models of AiCM rely on invasive techniques, such as implantable pacemakers, which are low-throughput and technically challenging. In contrast, optogenetics allows for light-based cardiac pacing, which, in transparent zebrafish larvae, offers a non-invasive, high-throughput platform for studying AiCM and identifying novel pharmacological treatments. In this study, we aimed to develop in vivo optogenetic models of AiCM using larval zebrafish to investigate the effects of arrhythmias on cardiac function, structure, and gene expression. We utilized zebrafish with cardiac-specific expression of cation-nonspecific channelrhodopsin-2 (ChR2) or chloride-specific anion channelrhodopsin-1 (ACR1) and exposed them to three arrhythmia protocols: intermittent tachypacing, a 33% ectopic burden, or a 50% ectopic burden through programmed light pulses at 2-7 days post-fertilization. GFP-expressing zebrafish exposed to the same light patterns served as controls. The mechanical function of the atrium and ventricle was assessed in live zebrafish at 7 dpf through brightfield recordings, while structural changes were evaluated in fixed samples using fluorescent microscopy. Additionally, we examined the expression of genetic biomarkers associated with cardiomyopathy using qRT-PCR. Our findings revealed that both tachypacing and ectopic pacing induced significant changes in cardiac structure, function, and gene expression. Intermittent tachypacing induced the most severe dysfunction, followed by the 50% ectopic burden and 33% ectopic burden. Across all protocols, ChR2-expressing fish showed more pronounced changes than ACR1-expressing fish. Specifically, both tachypacing and ectopic pacing resulted in increased end-diastolic area (EDA), end systolic area (ESA), stroke area (SA), and decreased ejection fraction (EF), with changes in gene expression indicative of chamber wall stretch, hypertrophy, inflammation, and fibrosis. To explore the therapeutic potential of this model, we tested the effects of fimasartan on tachypacing-induced dysfunction. Preliminary results demonstrated that 50µM fimasartan improved cardiac function and attenuated structural remodeling in the zebrafish heart, highlighting the potential of this model as a high-throughput platform for therapeutic drug screening.Item Open Access ADDRESSING CLASS IMBALANCE IN HIERARCHICAL MULTILABEL CLASSIFICATION WITH NODE-WISE WEIGHTING(2025-06-13) Sharma, Ayushi; Not Applicable; Master of Computer Science; Faculty of Computer Science; Not Applicable; N/A; Not Applicable; Dr. Israat Haque; Dr. Gabriel Spadon De Souza; Dr. Thomas TrappenbergClass imbalance is a persistent challenge in hierarchical multilabel (HML) classification tasks where labels form parent-child relationships and samples contain more than one label. It hampers learning as the majority classes dominate training while minority classes are neglected, which is amplified due to hierarchical dependencies. We introduce an adapted node-wise weighting method that enforces hierarchical constraints and reimagine HML imbalance as defined by node frequencies in a dataset. We benchmark it on several HML datasets including functional genomics datasets and an oceanographic dataset. We analyze which evaluation metrics provide a comprehensive assessment that is specifically suited for assessing HML tasks. The experimental results show that our node-wise weighting method consistently improves recall for minority classes without sacrificing much precision on majority classes, outperforming prior techniques for handling class imbalance. These findings show the potential of our method to address class imbalance in HML settings applicable to diverse real-world HML tasks.