Theses and Dissertations
This collection contains theses and dissertations of graduate students of the University of Alberta. The collection contains a very large number of theses electronically available that were granted from 1947 to 2009, 90% of theses granted from 2009-2014, and 100% of theses granted from April 2014 to the present (as long as the theses are not under temporary embargo by agreement with the Faculty of Graduate and Postdoctoral Studies). IMPORTANT NOTE: To conduct a comprehensive search of all UofA theses granted and in University of Alberta Libraries collections, search the library catalogue at www.library.ualberta.ca - you may search by Author, Title, Keyword, or search by Department.
To retrieve all theses and dissertations associated with a specific department from the library catalogue, choose 'Advanced' and keyword search "university of alberta dept of english" OR "university of alberta department of english" (for example). Past graduates who wish to have their thesis or dissertation added to this collection can contact us at erahelp@ualberta.ca.
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Item Open Access Atomistic Modelling: Microstructure and Disorder Effects on the Dynamic Mechanical Response of Advanced Ceramics(Spring 2025) Chang, Junhao|Department of Mechanical EngineeringThis thesis investigates dynamic failure mechanisms in advanced ceramics, with a specific focus on α-Al2O3, through the integration of molecular dynamics (MD) simulations, cross-scale modeling, and machine learning techniques. Using the Charge-Optimized Many-Body (Comb3) potential, the atomic models are validated to accurately represent key physical properties such as Young’s modulus (350 GPa), shear modulus (140 GPa), and fracture toughness (3.0 MPa·m1/2). Microstructural features, derived from high-resolution experimental techniques like Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDS), are incorporated into the models to analyze the effects of voids and defects, with a focus on porosity levels ranging from 2% to 12%. The research employs cross-scale bridging methods, including the Atomistic-to-Continuum (ATC) approach, to link atomic-scale simulations with continuum-scale models, enabling accurate predictions of fracture mechanics parameters. Specifically, critical stress intensity factors (KICP ) ranging from 1.5 to 4.5 MPa √ m are predicted for various defect configurations. Furthermore, machine learning techniques such as Gaussian Mixture Models (GMM) and Support Vector Machines (SVM) are applied to improve the predictive accuracy of the MD simulations. These techniques help establish relationships between microstructural features—such as porosity—and macroscopic mechanical properties like fracture strength (ranging from 10 to 30 GPa) and crack propagation speed (ranging from 1000 to 12000 m/s). The results contribute to a deeper understanding of the dynamic failure behavior of ceramics and provide a robust framework for designing more resilient ceramic materials under extreme loading conditions. Ultimately, this work lays the foundation for more reliable material design in critical applications, where high performance and durability are essential for advancing technologies in aerospace, energy, and other industries.Item Open Access Experimental Measurements and Theoretical Modeling of Dissociation Pressure of Gas Hydrates with the Presence of Thermodynamic Inhibitors(Spring 2025) Zhou, Ying|Department of Civil and Environmental EngineeringGas hydrates have diverse offshore applications, including carbon capture and storage (CCS), flow assurance, and seawater desalination. Seawater electrolytes present in these processes act as thermodynamic hydrate inhibitors (THIs). THIs alter the dissociation conditions of gas hydrates by reducing water activity. However, the thermodynamic effects of various seawater electrolytes on gas hydrates remain underexplored, leaving the role of ion specificity in affecting dissociation conditions unclear. Literature lacks experimental data on the dissociation pressure of CO2 hydrate in sulfate solutions. Using an in-house experimental setup, we employ the isochoric pressure-search method to measure the dissociation conditions of CO2 hydrate in various sulfate solutions (including Na2SO4, K2SO4, MgSO4, and CuSO4). The measured data are used to validate a thermodynamic model that incorporates Soave-Redlich-Kwong Equation of State (SRK EOS) (Soave, 1972), van der Waals-Platteeuw (vdW-P) model (van der Waals and Platteuw, 1959), and Pitzer model (Pitzer and Mayorga, 1973) to predict the dissociation pressure of CO2 hydrate in these sulfate solutions. The combined experimental and predicted results reveal that the CuSO4 solution exhibits a weaker thermodynamic inhibition effect than the other three solutions, likely due to its lower ion concentration and specific ion effects. To further investigate the effect of ion specificity on the dissociation pressure of CH4 and CO2 hydrates, we utilize the same apparatus and experimental procedure to measure the dissociation conditions of these hydrates in NaI and KI solutions. We systematically compare the thermodynamic inhibition effects of chloride, sulfate, and iodide solutions on CH4 and CO2 hydrates, finding that ion specificity only affects the thermodynamic inhibition of CO2 hydrate (not CH4 hydrate), with anions playing a dominant role. Additionally, the integrated SRK-vdW-P-Pitzer model is applied to predict the dissociation pressure of CO2 hydrate in these iodide solutionsItem Open Access The use of uterine horn resection surgery to optimize non-surgical embryo collection in gilts and sows(Spring 2025) Ewasiuk, Mikayla E|Department of Agricultural, Food, and Nutritional ScienceNon-surgical embryo collection (nsEC) and transfer have proven to be financially beneficial practices across a multitude of livestock sectors, justifying their demand in the swine industry. Currently, the conventional methods for collecting pig embryos involve either a costly and invasive surgical procedure or a terminal post-slaughter collection. Over the last several decades, the pursuit to standardize the techniques of swine nsEC has encountered significant challenges. The impediments limiting the widespread adoption of nsEC include the narrow cervical canal and convoluted structure of uterine horns (UHs), as well as the requirement for a specialized catheter to traverse through the uterus. The objectives of this study were to explore a transitional surgical model involving an ipsilateral, otherwise known as a ‘single-sided’ resection, to enhance access to the utero-tubal junction and better facilitate embryo retrieval upon implementing a transcervical catheter procedure. A contralateral ovariectomy was performed to evaluate the ovarian response of a single ovary. Optimizing nsEC would support the evaluation of embryo survival, quality, and interactions within the uterus. When combined with embryo transfer, these methods would offer a superior and cost-effective means of disseminating swine genetics and safeguarding herd health from pathological agents while concurrently addressing animal welfare concerns associated with live animal transport by reducing the use of this convention. During this research investigation, purebred dam- and sire-line gilts (parity zero; n = 15) and sows (parities one through five; n = 8) underwent a multi-step UH resection surgery to shorten the UH tissue, excise the contralateral ovary, and ligate the contralateral horn to produce an ipsilateral 40 cm UH. The three subsequent estrous cycles following the surgical procedure were reserved for uterine healing and recovery. After the recovery period, a series of nsECs involving uterine flushing were conducted between days 4 and 8 of the estrous cycle, following the onset of estrus (day 0) and cervical artificial insemination. In the gilt group, across 50 nsECs, the mean embryo media recovery was 57.8 ± 26.8% (mean ± sd), while in the sow group, across 49 nsECs, it was 76.0 ± 17.0%. Collectively, between the gilts and sows, 140 oocytes and embryos were retrieved using transcervical catheterization, gleaning that the application of non-surgical techniques is a feasible approach to harvesting embryos in pigs. Additionally, superovulatory ovarian hypertrophy was observed between the surgical procedure and post-slaughter assessment in the dam- and sire-line pigs. This was demonstrated by an increase in the number of corpora lutea (13.4 and 3.0 vs 27.2 and 12.0, P < 0.05) and intact ovary weight (11.9 and 7.7 vs 25.9 and 38.7 g, P < 0.05), respectively. Our efforts focused on attaining consistently elevated embryo media recovery rates and potential embryos using nsEC procedures. We envision that a refined catheter design and the use of second parity maternal breed sows will serve as pivotal components in streamlining embryo recovery procedures, representing a noteworthy advancement in the quest to improve the efficiency of swine reproduction. This pioneering approach is anticipated to be fundamental in propelling the broader field of assisted reproductive technologies within swine breeding and the industry as a whole.Item Open Access Advanced High-Temperature Alloys and Oxides: Design, Performance, and Optimization of Complex Concentrated Alloys and Thermally Grown Oxides(Spring 2025) Sun, Haofei|Department of Chemical and Materials EngineeringThe increasing demands for high-temperature (HT) structural materials in energy, aerospace, and waste-to-energy industries have driven research into advanced alloys capable of withstanding extreme environments. This study investigates the oxidation, hot corrosion resistance, and thermodynamic stability of commercial alloys, complex concentrated alloys (CCAs), and thermally grown complex concentrated oxides (TG-CCOs) for HT applications. The research begins by evaluating the hot corrosion performance of Fe- and Ni-based commercial alloys in simulated combustion environments, identifying their limitations at 850°C under Na₂SO₄-NaCl salt mixtures. The study then shifts focus to Fe-Cr-Ni multi-principal element alloys (MPEAs), which exhibit improved corrosion resistance at 700–900°C. Element selection plays a pivotal role in optimizing hot corrosion resistance in MPEAs. It is important to avoid using elements with high corrosion activity, such as Mn, and to reduce the relative contents of Fe and Ni. This is essential to control the formation of unprotective corrosion layers and prevent the decomposition of the alloy. Phase stability and diffusion mechanisms during oxidation of FeCrNi medium entropy alloys (MEAs) are analyzed through experimental observations and density functional theory (DFT) calculations. Key findings include the importance of temperature-dependent transformation from FCC to BCC and Cr diffusion in forming protective oxide layers, enhancing HT oxidation resistance. The study on diffusivities, phase structures, and oxidation behavior in the FeCrNi alloy establishes a strong foundation for advancing HT alloys with enhanced oxidation resistance. The hot corrosion resistance primarily depends on the thermally grown oxide layer (TGO) and the phase stability of the structural base alloy. Therefore, this study also explores the corrosion resistance and structural stability of TG-CCOs on a novel AlCrTiVNi5 alloy. These TG-CCOs demonstrate remarkable thermodynamic stability and corrosion resistance, with a significant structural transition from rock-salt to corundum oxides under HT conditions. Moreover, lattice distortion assessments suggest that these structural changes enhance the durability of the oxides. These findings establish TG-CCOs as promising candidates for next-generation protective coatings. This comprehensive study addresses critical gaps in materials science by providing insights into the design, performance, and optimization of CCAs and TG-CCOs. The outcomes contribute to advancing HT structural materials, offering significant potential for improving energy efficiency, reducing emissions, and extending the service life of components in extreme environments.Item Open Access Update on the state of practice for energy measurements in the Standard Penetration Test(Spring 2025) De Oliveira, Bruna Leal Melo|Department of Civil and Environmental EngineeringThe Standard Penetration Test (SPT) is an in situ test widely used to provide information o n soil geotechnical properties. The SPT N value obtained from the test is commonly employed in various geotechnical design correlations, particularly for soil characterization and foundation design. Although the development and adoption of other in situ te sting techniques, such as the C one Penetration Tests (C PTu and a variety of sensors available for deployment, SPT testing has continued to be a standard part of geotechnical practice, especially due to its simplicity, ability to collect soil samples and l ow cost. However, d espite its simplicity and cost effectiveness, the SPT faces challenges in reliability due to variability introduced by factors such as equipment calibration, operator inconsistencies, soil heterogeneity, drilling disturbances, and impact energy transfer. Among these, the amount of hammer energy delivered into the drill rods to the soil sampler is a critical factor affecting the SPT N value. Research has shown that discrepancies in SPT N values can be minimized through accurate energy mea surements, obtained using specialized instruments such as strain gauges and accelerometers mounted on the drill rods or anvil. These devices record force and velocity during the hammer's impact to the anvil, allowing for the calculation of transferred ener gy through methods like force velocity integration. By combining these measurements, engineers can determine the energy that reaches the rods and compare it to the theoretical potential energy of the hammer's free fall. The ratio of measured energy to theo retical energy, known as the Energy Transfer Ratio (ETR), provides insights into the system's efficiency and highlights energy losses due to factors like friction, misalignment, or equipment variability. This study provides a comprehensive review of resear ch and advancements in hammer energy measurement techniques for the SPT, emphasizing their critical role in achieving more reliable N values , and provides example estimates of the influence of this variability on the calibrated SPT N value and interpretati on of geotechnical parameters from it . By addressing energy variability and promoting standardized measurement practices, the findings contribute to enhancing the accuracy of geotechnical investigations and reducing uncertainties in engineering application s. T he work in this thesis then focuses on SPT tests with ener g y measurements in the field, under controlled conditions to evaluate the efficiency of automatic hammers in SPT This is done by comparing their performance with Pile Driving Analyzers (PDAs) under two testing methodologies: continuous and resetting at every 18 inches. Data collected at varying depths examined the influence of rod length and operational methodology on energy transfer dynamics. Results indicate that automatic hammers consistently achieve efficiency values exceeding 80%, with variations influenced by testing methods and depth. The study underscores the need for continued innovation and standardization in SPT practices to enhance geotechnical ana lyses and design outcomes globally , as well as the importance of energy measurements to properly calibrate SPT N values and reduce the uncertainty in interpreted material parameters from SPT tests.Item Open Access Development of Protein Microgels Using a Novel Water-in-Water Emulsion Method and Their Functional Applications(Spring 2025) Chu, Yifu|Department of Agricultural, Food, and Nutritional ScienceMicrogels have garnered increasing attention as versatile building blocks and functional ingredients for applications in food science, biomaterials, and beyond. This PhD research aims to address the current challenges in developing uniform, size-controllable protein microgels and exploring their performance in bulk and interfacial systems to create innovative solutions for healthier food products and functional biomaterials. In the first study, a facile water-in-water (W/W) emulsion method was innovated to prepare whey protein microgels based on protein-polysaccharide segregative phase separation. This approach enables precise control over microgel sizes (1–20 μm) with uniform distribution and offers two significant advantages over traditional microgel fabrication methods: 1) The W/W droplets can remain stable without adding surfactants, enhancing biocompatibility for food and biomedical applications; 2) the process requires low energy input due to the ultra-low interfacial tension of W/W droplets, improving commercialization potential. Oil-in-water emulsion stabilized by these microgels demonstrated exceptional stability and textural properties, prompting our further investigation into the underlying emulsification mechanisms of this system. The second study demonstrated two key stabilization mechanisms: 1) microgels adsorbing at the oil/water interface to stabilize Pickering emulsions and 2) microgels dispersing in the continuous phase to act as fillers to enhance emulsion texture. Varying microgel content effectively tailored the rheological properties in both scenarios. Proteins contribute fewer calories than fat, thus showing strong potential as fat replacers for developing novel low-calorie foods with enhanced texture and reduced fat content. The third study shed light on the lubrication performance and underlying mechanism of these protein microgels, which is essential for predicting the fat-mimic mouthfeels, such as creaminess. It was observed that the microgel suspension showed several folds of reduction in coefficient of friction in comparison to native protein and human saliva via tribological measurements. The exceptional lubricity was from a synergistic effect of the ball-bearing mechanism and the hydration state of the microgels. Granular hydrogels are a promising class of 3D-printable inks but often suffer from low printing resolution due to large microgel sizes (>100 μm). In the last study, we developed a novel class of granular hydrogels (WMGH) composed of uniform, size-controllable whey protein microgels. The small microgel size enabled WMGH ink to achieve high 3D printing resolution to produce intricate constructs such as aortic valve structures with high fidelity. By incorporating a polyacrylamide second percolating network, WMGH inks were transformed into stretchable, tough double-network granular hydrogels (DN-WMGH). Controlling microgel size offered a new approach to tailor mechanical strength (6–300 kPa), idea for tissue-mimicking applications. This work developed a novel, facile method to produce protein microgels via protein-polysaccharide segregative phase separation, demonstrating strong industrial potential. This research signified the value of these uniform, size-controllable protein-based microgels as functional ingredients for developing healthier food products and functional biomaterials. Notably, this research supports the development of fat-reduced foods with enhanced mouthfeel comparable to full-fat counterparts, providing healthier dietary options without sacrificing sensory appeal. Additionally, it expands the potential of these microgels for biomaterial applications, including tissue-mimicking implants and 3D bioprinting for tissue regeneration, contributing to healthier outcomes.Item Open Access Food Protein-Derived Peptides with Angiotensin-Converting Enzyme 2 (ACE2) Up-regulatory Activity(Spring 2025) Wang, Zihan|Department of Agricultural, Food, and Nutritional ScienceAngiotensin-converting enzyme (ACE) and angiotensin-converting enzyme 2 (ACE2) are two key enzymes responsible for blood pressure regulation in the renin-angiotensin system. ACE catalyzes the formation of a vasoconstrictor peptide, angiotensin II (Ang II), while ACE2 converts Ang II into a vasodilator peptide, angiotensin (1-7) (Ang (1-7)). Bioactive peptides like IRW exhibit blood pressure lowering activity via upregulation of ACE2 and then activation of ACE2 axis, not via direct ACE inhibition, in spontaneously hypertensive rats (SHRs). The overall objective of this thesis is to explore the structures and mechanisms of bioactive peptides with ACE2 up-regulatory function. This first study aimed to determine if peptides with ACE inhibitory activity can also activate ACE2. About two hundred ACE inhibitory peptides derived from literature were first subjected to molecular docking. Among 20 peptides selected for cell and enzymatic activity studies, of 5 peptides were orally administered to SHRs at a dose of 15 mg/kg body weight/day for 7 days. Peptides IKW and RIY showed significant antihypertensive activity with activated circulating/aortic ACE2, increased circulating Ang (1-7) and decreased Ang II levels. IQY reduced blood pressure, increased Ang (1-7) level but did not affect ACE and ACE2. Peptides MAW and MRW did not affect blood pressure, ACE and ACE2. Our study showed that ACE2 upregulation/activation is not a common feature of ACE inhibitory peptides. The second study investigated the antihypertensive mechanisms of peptides IKW and RIY. Both peptides reduced vascular inflammation and oxidative stress by modulating the mitogen- activated protein kinase and nuclear factor kappa B pathways, lowering aortic nitrotyrosine and calcium levels, and shifting the oxylipin profile toward anti-inflammatory species. In VSMCs under Ang II stimulation (1 μM or 10 nM), they reduced reactive oxygen species, calcium levels, interleukin-1β, and cyclooxygenase 2 (COX2) levels. COX2 inhibition was linked to ACE2 and sirtuin-1 (SIRT1) upregulation, with SIRT1 contributing to ACE2 expression, as knocking down ACE2 or blocking SIRT1 diminished these effects. These findings suggest IKW and RIY’s anti- inflammatory and antioxidative effects in the vasculature of SHRs and in Ang II-stimulated VSMCs. Given that IRW strongly upregulates ACE2 and is more effective in lowering blood pressure in SHRs than peptides IKW and RIY, its bioavailability was investigated. Rats were administered 100 mg IRW/kg body weight via intragastric or intravenous routes. The bioavailability (F%) was 11.7%, with half-lives of 7.9 ± 0.5 and 28.5 ± 6.8 min for gavage and injection, respectively. Significant blood pressure reduction was not observed until 1.5 h post oral administration, or 2 h post injection, indicating that IRW’s metabolites likely contribute to this effect. Time-course metabolomics revealed a significant increase in kynurenine, a tryptophan metabolite, after IRW administration. Kynurenine increased ACE2 in EA.hy926 vascular endothelial cells. Oral administration of tryptophan, but not dipeptide Ile-Arg, lowered blood pressure and upregulated aortic ACE2 in SHRs, supporting the role of tryptophan and kynurenine in IRW’s acute blood pressure-lowering effects. Further investigation into IRW’s long-term effects on ACE2 regulation was conducted through transcriptomics and metabolomics. Transcriptomic analysis of mesenteric arteries revealed 11,778 mRNAs, with 651 co-expressed with ACE2. Combining weighted gene co- expression network analysis (WGCNA) with transcription factor predictions, 17 potential ACE2 transcription factors were identified, including nuclear receptor subfamily 4 group A member 1 (Nr4a1). Concurrent metabolomic analysis identified 421 metabolites, with dopamine significantly increased following IRW treatment (fold change of 3.66, p = 0.037). Twenty-six metabolites, including dopamine, displayed expression levels similar to ACE2, indicating their involvement in ACE2 regulation. Ingenuity pathway analysis suggested that dopamine might activate Nr4a1 transcription via the dopamine D1 receptor (D1R). In EA.hy926 endothelial cells, dopamine (1 μM) increased ACE2 and Nr4a1 expression, an effect blocked by the D1R antagonist SCH23390 (10 μM). Nr4a1 knockdown reduced dopamine-induced ACE2 protein expression. In SHRs, D1R dependency was confirmed, as SCH23390 infusion abolished IRW’s antihypertensive effects and ACE2 upregulation. Although IRW lacks tyrosine, the rise in dopamine was attributed to increased DOPA decarboxylase and its cofactor pyridoxal 5’-phosphate. This research advances understanding of IRW’s in vivo ACE2 upregulation and its potential in preventing ACE2-associated diseases. Notably, the application of omics analyses to investigate the mechanisms of action of bioactive food compounds offers an innovative direction for future research in this area.Item Open Access An Evaluation of Physician and Patient Opinions with Patient Outcome Assessment to Inform Post-Procedure Driving Guidelines following Transcatheter Aortic Valve Insertion: TAVI-D (The Post-TAVI Driving Study)(Spring 2025) Jarvis, Catherine R|Department of MedicineBackground: Surgical aortic valve replacement (SAVR) and transcatheter aortic valve insertion (TAVI) are known treatments for severe aortic stenosis. TAVI is a minimally-invasive method with shorter recovery time when compared to SAVR. In October 2023, the Canadian Cardiovascular Society (CCS) released their Fitness to Drive Guidelines and recommended a one-month post-procedure driving restriction for both SAVR and TAVI patients. Adequate post-TAVI patient clinical data was lacking to inform such a guideline. Methods: A dual-component study was created to 1) assess Canadian TAVI centre’s opinions on the one-month driving restriction and recovery post TAVI and 2) analyze TAVI patient outcomes and gather data on patient opinions and driving habits to inform an updated post-TAVI driving guideline. A 15-question survey was distributed to 31 Canadian TAVI centres in April 2024. From June 2024 to January 2025, TAVI patient recovery was clinically assessed through a short-term longitudinal prospective observational study at the Mazankowski Alberta Heart Institute (MAZ). A 17-question survey was also circulated to all enrolled post-TAVI patients (30-90 days post procedure) to examine one-month post-procedure recovery and collect opinions on the driving restriction. Results: Twenty-five (80.6%) TAVI centres participated. Twenty-nine TAVI physicians and site coordinators provided responses. 20.7% expressed that a one-month driving restriction was appropriate while most (79.3%) stated that such a guideline was ‘too long’. Recommendations for a new driving guideline for post-TAVI patients having undergone a successful, uncomplicated, transfemoral (TF) procedure were as follows: 48 hours (6.9%), 72 hours (6.9%), one week (24.1%), two weeks (41.4%), three weeks (6.9%), and one month (13.8%). Developing conduction abnormalities was the main (89.7%) listed post-TAVI driving concern. Driving guidelines >1 month were proposed for patients with transapical TAVI (67.7%), alternative arterial access TAVI (51.6%), access-site or vascular complications (48.4%), or conduction disturbances without pacemaker insertion (45.2%). One hundred and eleven TAVI patients fully participated in the observational and survey-based study. One hundred and nineteen patients originally consented to enrolment although eight were removed for meeting exclusion criteria: deceased during TAVI (n=1), deceased post TAVI (n=3), and withdrawn for other reasons (n=4). The one-month driving restriction was felt to be ‘too long’ by 52.3% of participants. Pacemaker implantation during clinical study follow-up occurred in 20 patients (n=20/111, 18%), with 65% occurring during TAVI hospitalization. All patients who experienced conduction abnormalities and underwent pacemaker implantation post TAVI reported feeling symptomatic between TAVI hospital admission and one week post except one at two weeks. Of the seven who returned to hospital for pacemaker insertion, 71.4% (n=5) of readmissions occurred within two weeks and 28.6% (n=2) >3 weeks. Only one patient without existing or post-TAVI conduction disturbances before discharge developed new RBBB and required pacemaker insertion one week after TAVI. The other 95% of pacemaker patients had known conduction disturbances or newly developed them post procedure before leaving hospital. Immediate post-procedure access-site-related complications (n=4, 3.6%) were manageable and resolved during TAVI admission. Conclusion: A one-month post-TAVI driving guideline was considered overly cautious by most Canadian TAVI centres. In conjunction with patient recovery data, considering shortening the driving restriction to <2 weeks for successful uncomplicated TF TAVI patients without pre-existing or new post-TAVI conduction abnormalities is proposed.Item Open Access The Role of Speech-Language Pathologists in Addressing Depression in Adults with Aphasia: A Scoping Review and A Qualitative Study(Spring 2025) Borjianboroujeni, Golnoush|Faculty of Rehabilitation MedicineAbstract People with aphasia (PWA) are at a heightened risk of developing depression, which can, in turn, impede their recovery from aphasia. This complex interplay underscores the critical need for evidence-based services that address both the communication challenges of aphasia and the mental health impacts of depression. Despite this, PWA are often excluded from studies on post-stroke depression due to their communication difficulties. Speech-language pathologists (SLPs) are uniquely positioned to support individuals with dual diagnoses of aphasia and depression, leveraging their specialized training in communication, supported communication strategies, and counselling skills. However, many SLPs lack sufficient knowledge or feel unprepared to address mental health issues in PWA, as this is an emerging area of practice that is only beginning to gain wider attention. This thesis investigated the role of SLPs in managing depression in PWA through two interconnected studies: a scoping review and a qualitative study. The scoping review synthesized existing evidence on SLP-led practices for addressing depression in PWA, focusing on assessments, interventions, barriers, and facilitators. Databases searched included Medline, Embase, CINAHL, PsycINFO, LLBA, and Scopus, covering studies published up to October 2023. The qualitative study complemented the review by exploring the lived experiences of SLPs through semi-structured interviews, providing insights into how theoretical practices are applied in real-world clinical settings. Findings from both studies revealed that informal assessment methods, such as clinical observations and reports from patients and caregivers, are commonly used by SLPs to identify depression in PWA. While the scoping review identified validated tools for assessing depression, the qualitative study revealed that these tools were seldom utilized in practice. Instead, informal assessments remained central to SLP-led care, highlighting a gap between the availability of evidence-based tools and their application in clinical settings. Both studies emphasized the vital role of SLPs in delivering behavioral interventions with low language demands, counseling strategies, and social support initiatives. Although the scoping review identified specialized psychotherapeutic approaches, such as Intensive Language-Action Therapy (ILAT) and Comprehensive Aphasia Programs (ICAPs), the qualitative findings indicated that these evidence-based approaches are rarely implemented in practice. Barriers to addressing depression in PWA, identified in both the scoping review and the qualitative study, existed at systemic and individual levels. Systemic barriers included inadequate training and education, insufficient staffing, and limited resources. Individual barriers arose from communication difficulties and patients’ reluctance to engage in therapy. Despite these challenges, both studies also highlighted key facilitators, including interdisciplinary collaboration, access to professional development opportunities, and the integration of mental health education into routine SLP practices. These facilitators offer promising avenues to address the identified gaps in care. Together, these findings contribute to a comprehensive understanding of the disconnect between evidence-based practices and their implementation in clinical settings. They highlight the urgent need for enhanced training programs, improved resource allocation, and interdisciplinary approaches to empower SLPs to meet the psychosocial needs of PWA. This research lays a foundation for future studies aimed at bridging these gaps and improving mental health outcomes for PWA through tailored, accessible, and sustainable services.Item Open Access Life Cycle and Techno-Economic Assessments of a Dual Output Facility Producing Lithium Hydroxide Monohydrate and Lithium Carbonate(Spring 2025) Rathore, Saurav S|Department of Mechanical EngineeringThe urgent need to combat climate change and achieve carbon neutrality is driving the demand for clean energy technologies, particularly lithium-ion batteries, which play a pivotal role in electric vehicles (EVs) and renewable energy storage systems. This thesis integrates a life cycle assessment (LCA) with a techno-economic assessment (TEA) to provide a comprehensive evaluation of dual-output lithium production pathways involving lithium hydroxide monohydrate (LHM) and lithium carbonate (Li₂CO₃) from spodumene ore. The LCA focused on the environmental impacts of a facility designed to process 250 tonnes per hour (TPH) of spodumene ore using advanced electrodialysis technology. The results indicate that the facility requires 175.6 Megawatts (MW) of energy, with the electrochemical process and mining contributing 97.2 MW and 49.6 MW, respectively. Electrodialysis alone consumes 65.7% of the total energy, accounting for approximately 36% of the energy required for LHM production. The life cycle greenhouse gas (GHG) emissions are estimated at 9.15 t CO₂e per tonne of LHM, with the electrochemical process and mining contributing 5.48 t CO₂e/t LHM and 1.85 t CO₂e/t LHM, respectively. In a simultaneous production scenario (50% LHM, 50% Li₂CO₃), life cycle emissions increase by 0.6%. Sensitivity and uncertainty analyses identify scalability and electricity emission factors as critical variables influencing emissions. The TEA evaluated the economic feasibility of the same facility and found a total capital expenditure (CAPEX) of CAD 2.4 billion and an annual operating expenditure (OPEX) of CAD 529 million. The electrochemical plant accounts for 61% of CAPEX, reflecting the cost-intensive nature of downstream processing, while energy costs dominate OPEX at 33% (CAD 174 million). The facility achieves a minimum selling price of CAD 14,979 per tonne of LHM, with a payback 3 period of approximately four years and a breakeven net present value at a 15% discount rate. Sensitivity analysis highlights scalability, energy prices, and expected rate of return as critical parameters, with scalability alone causing MSP deviations of up to CAD 1,400 per tonne. By integrating LCA and TEA, this research provides actionable insights into the environmental and economic dimensions of dual-output lithium production. It highlights strategies to optimize costs, scalability, and operational efficiency while addressing the rising global demand for lithium-ion batteries, contributing to the global transition to clean energy technologies.Item Open Access Trauma-informed Care: An Emerging Approach to Better Healthcare Experiences for Patients(Spring 2025) San, Julie|School of Public HealthAccording to the World Health Organization (WHO), approximately 70% of the world population has experienced a traumatic event in their lifetime (World Health Organization, 2024). These events can be wars, accidents, natural disasters or violence. Even though some people will temporarily experience distress and recover over time, others will face lasting physical or mental health effects. As people who have experienced trauma are potential healthcare users, they can more likely be re-traumatized during their healthcare experiences. Trauma-informed care (TIC) is an approach that recognizes and identifies the symptoms and signs of trauma. It allows healthcare providers (HCPs) to provide services that responds to the impact of trauma on an individual’s well-being and behaviour. As this study is a quality improvement study, it first examines if an implementation of a TIC education program can improve the knowledge, attitudes, and beliefs of healthcare providers. Furthermore, the second purpose is to find key features, improvements, and barriers. This work will be used for future TIC program developments at the Lois Hole Hospital for Women in Edmonton, Alberta. The TIC training program was delivered in two parts in November 2023 and April 2024. Program content was created and taught by TIC experts at the Lois Hole Hospital for Women. The first part consisted of a didactic lectures, while the second part were group discussions and practical applications. A total of 19 participants attended, and most of them were in leadership or educator roles. Semi-structured individual interviews were conducted in the month of January 2025. Out of 19 participants, 8 participants were interviewed either online or in-person. A qualitative content analysis was done through coding to form themes. All participants participated in member checking to ensure their responses were represented accurately. Four themes were found for the TIC experiences of the participants: i) enhanced understanding of Indigenous health and culture, ii) improved clinical practice, iii) enhanced awareness, and iv) sharing knowledge with other staff members. For key features of the program, participants appreciated: i) guest speakers, ii) live stories, and iii) practical applications. Participants also highlighted several trauma-informed care (TIC) that they find valuable: i) reflexivity, ii) consent, and iii) communication. The following barriers arose when participants practiced TIC: i) change-resistant staff, ii) time, iii) pressure, iv) organizational barriers. Participants described improvements for future TIC training programs, which were: i) more frontline staff, ii) addition of other cultures and trauma, iii) closer TIC sessions. The TIC training program had shown to improve knowledge and positively alter perceptions of HCPs. HCPs found the importance of being more aware of their patient interactions, incorporating consent and communication. The most valuable part of the training sessions were when participants were taught to apply their knowledge into their practice. This allowed them to be more empowered to make changes. However, several considerations are noted for future sessions. If those barriers are reduced, more HCPs are encouraged to use the approach. Finally, the participants have expressed the need to bring in more frontline staff and other cultures and trauma to the sessions to maximize the effectiveness of trauma-informed practice.Item Open Access High-resolution Numerical Modelling to Investigate the Atmospheric, Glacial, and Hydrological Dynamics in the Himalaya(Spring 2025) Tiwari, Ujjwal|Department of Earth and Atmospheric SciencesInvestigating the atmospheric, glacial, and hydrologic dynamics over the Himalaya is particularly challenging due to its complex topography and limited availability of station data. The uncertainties are further amplified by the profound impacts of global climate change, which significantly influence the region’s atmospheric, glacial, and hydrological responses. While global and regional climate models perform well over relatively flat terrain, they often fail to capture the spatial variability of the atmospheric field in the Himalaya. In this context, well-validated, process-based numerical models offer a promising alternative for studying these dynamics. The Weather Research and Forecasting (WRF) model used in this study is a dynamic atmospheric model used in both operational weather forecasting and atmospheric research. This study uses the WRF model to (a) improve extreme precipitation forecasting skills, (b) explore the intricate relationship between the topography and atmospheric dynamics, and (c) apply the well validated WRF output to drive a new glacial-hydrological model in the Himalaya. This study has demonstrated that the well validated WRF model can accurately reproduce the surface meteorological variables and provide insightful information to investigate the influence of topography in convection, cloud formation, and precipitation generation. To study the glacial-hydrologic dynamics over the Himalaya, a process-based glacial model (Crocus) is coupled with an advanced, fully distributed hydrologic model, WRF-Hydro. The coupled model, thus called the WRF-Hydro/Glacier, when combined with the WRF atmospheric model, offers the potential to accurately simulate the glacial and hydrologic processes in the world’s most complex topography.Item Open Access Sorted Bucket Hash and Combinatorial Game Algorithms: Two Efficient Solvers for the Game of NoGo(Spring 2025) Du, Haoyu|Department of Computing ScienceNoGo is a variant of the popular game of Go. NoGo shares the same mechanisms as Go, but it requires stones, once played, to be not removed from the board. Strong computer players have been created for NoGo, yet the game properties and optimal play strategies are not well studied. This thesis describes our recent contributions to solving and understanding NoGo. Two solvers were developed for this purpose: SBHSolver and CGTSolver. SBHSolver uses a newly proposed Sorted Bucket Hash hashing method and its general data structure to build the transposition table. It is capable of weakly solving games on memory-limited machines efficiently. CGTSolver equips Negamax search algorithm with enhancements derived from combinatorial game theory to solve Linear NoGo which is NoGo played on a one-dimensional board. SBHSolver weakly solved all NoGo positions of sizes up to 27 points, and CGTSolver pushed beyond and ultra-weakly solved Linear NoGo up to 39 points. Those achievements were made possible by the improved efficiency of these solvers. Statistical observations of game-playing strategies, rigorous proofs of combinatorial game properties, and detailed experimental results are provided in this thesis.Item Open Access The Influence of Restrictive Emotionality on Mental Health Help-Seeking Among University-Aged Men(Spring 2025) Kar, Priya|Faculty of Rehabilitation MedicineBackground: University students face a higher risk of mental health concerns as they navigate the transitional stress of adjusting to academic life. Amongst this population, men are particularly hesitant to seek mental health assistance, even when needed, largely due to the stoic expectations of traditional masculine norms. Restrictive emotionality, a key aspect of traditional masculinity, reinforces the belief that men must embody strength, discourage emotional expression, and stigmatize openness. Despite these social expectations, men often experience higher rates of mental distress but disclose it less frequently. Therefore, this study aimed to investigate how restrictive emotionality influences the mental health help-seeking attitudes and intentions of men enrolled at a large Canadian University. Methods: This study used a two-phased design. Phase One involved administrating a survey during the Fall 2023 semester to understand undergraduate men’s mental health, restrictive emotionality, and help-seeking attitudes and intentions, The survey included demographic questions along with four assessments: the Kessler Psychological Distress Scale (K10), the Restrictive Emotionality Subscale (RE-Subscale), the Mental Help-Seeking Intentions Scale (MHSIS) and the Mental Help-Seeking Attitudes Scale (MHSAS). Descriptive statistics were conducted to analyze the demographic distribution, while a Pearson correlation assessed the relations between the assessment scores. A multiple regression analysis was conducted to examine how K10, RE and MHSAS predicted MHSIS outcomes. In Phase Two, students scoring 4 or higher on the RE-Subscale were invited to participate in interviews to get an in-depth understanding of their mental health help-seeking experiences. Thematic analysis was used to analyze the interview data. Results: A total of 238 undergraduate men participated in the survey, with the majority (83%) aged between 17-22. The sample included a diverse group from various faculties and years of study, comprising both domestic and international students. The Faculty of Science had the highest representation, with 31.58% of participants, and 28% percent of all participants self-identified as having been diagnosed with mental health disorders. Despite overall moderate RE levels, averaging 3.599, moderate-to-severe mental distress was most prevalent, with 52.08% of students scoring in these ranges on K10. Moderate negative correlations were found between RE and MHSIS scores (r = -.243) and between RE and MHSAS scores (r = -.267). Three overarching themes emerged from the interview data regarding restrictive emotionality’s influence on men’s help-seeking attitudes and intentions: personal pathways, environmental and social influences, and the interplay between the two. Subthemes included family, friends, service accessibility and societal stigma, which contributed to a cyclical relationship with the internalized personal beliefs surrounding restrictive emotionality that the men embodied. Discussion and Conclusion: The findings of this study revealed that restrictive emotionality negatively influences men’s help-seeking attitudes and intentions, regardless of the severity of their mental distress. This may be linked to the strong social expectation for men to adhere to traditional masculine norms as a way of maintaining their sense of masculinity. Greater emphasis on these norms from family and friends reinforces both internal and external notions of restrictive emotionality when men face mental health distress. The stigma surrounding deviation from masculine expectations further discourages emotional expression, even in times of significant needs. These findings suggest that increasing societal acceptance of emotional expression among men, especially during times of distress, could foster help-seeking attitudes and intentions and reduce the stigma surrounding men’s mental health.Item Open Access Energy metabolism defects in childhood and adulthood(Spring 2025) Ambrose, Anastasia M|Medical Sciences-Medical GeneticsEnergy metabolism defects are rare metabolic genetic disorders. Their natural history, diagnostic odyssey and treatment outcomes are not widely reported. Their phenotypic landscape differs across the lifespan, and there is variability in the diagnosis and treatment modalities of these defects. They can be missed or misdiagnosed, which leads to impaired disease management and poor outcomes. To increase our knowledge of these energy metabolism defects, we studied their phenotypes, genotypes, treatment and management outcomes in individuals at our tertiary care center. We performed three studies included in this thesis. In Chapter 2, we assessed mitochondrial long-chain fatty acid oxidation and carnitine metabolism defects, a group of energy metabolism defects. We performed a retrospective cohort study to report the phenotypic and genotypic spectrum of mitochondrial long-chain fatty acid oxidation and carnitine metabolism defects and their treatment outcomes. We divided individuals into two groups to compare the outcomes of those treated symptomatically (SymX) and asymptomatically (AsymX). We reviewed charts for their clinical features, biochemical investigations, molecular genetic investigations, cardiac assessments, neuroimaging, treatments, and outcomes. There were 38 individuals: 14 were diagnosed SymX, and 24 were diagnosed AsymX. There were seven different mitochondrial long-chain fatty acid oxidation and carnitine metabolism defects in our study cohort. We found a statistically significant association between rhabdomyolysis and hypoglycemia with the SymX group compared to the AsymX group. We observed a higher number of hospital admissions, longer duration of hospital admissions and poorer outcomes in the SymX group. Overall, our findings emphasize the importance of early diagnosis and management of these energy metabolism defects to improve outcomes. In Chapter 3, we assessed primary mitochondrial diseases (PMD), energy metabolism defects caused by pathogenic variants in the mitochondrial (mtDNA) or nuclear genome (nDNA) that impair mitochondrial function. We hypothesized that PMD overlaps with other genetic diseases that mimic PMD. For this reason, we conducted a retrospective cohort study including individuals with suspected PMD who underwent molecular genetic and genomic investigations. We grouped individuals: 1) mtDNA-PMD, 2) nDNA-PMD, 3) non-PMD (genetic diseases mimicking PMD), and 4) those without a confirmed genetic diagnosis. Two hundred ninety-seven individuals fulfilled the inclusion criteria. We identified 71 patients with PMD (mtDNA n=41, nDNA n=30) and 22 patients with non-PMD. Adults had a higher percentage of mtDNA-PMD compared to children. We found a statistically significant phenotypic difference between children and adults with PMD. The diagnostic yield was 31.3% in our study cohort including the 37% diagnostic yield of exome sequencing, and 15.8% diagnostic yield of mitochondrial genome sequencing. Differentiating PMD from non-PMD can be achieved using specific phenotypes, with significant differences in muscular, cardiac, and ophthalmologic phenotypes, as well as seizures, hearing loss, and peripheral neuropathy in the PMD group compared to non-PMD. In Chapter 4, we investigated the genetic causes of neonatal encephalopathy (NE), characterized by abnormal consciousness with or without seizures in term newborns, using genome sequencing (GS). We used bioinformatic tools, in silico predictions, protein 3D modeling, and functional studies to assess variant pathogenicity. There were 17 newborns enrolled into the study. We identified twelve variants in ten genes, classifying four variants in four different genes including PPP2R5D, BCOR, CFL2, SCN2A) as pathogenic/likely pathogenic in previously established disease genes and seven as variants of uncertain significance (VUS) in one previously established disease genes (DST) and in five candidate genes (STAB2, CELF4, SORCS2, CTNND2, ASTN1). Functional studies confirmed SORCS2 variant pathogenicity and reclassified STAB2 variants as benign. The CELF4 and ASTN1 copy number variants (CNV) resulted in structural changes in protein 3D models, while the CTNND2 VUS caused a 3D protein structure shift. Overall, the diagnostic rate of research GS was 41%, and we expanded the phenotypes of four previously established disease genes and identified three candidate genes (SORCS2, CELF4, ASTN1) that may cause NE. We think that while protein 3D modeling is valuable for assessing CNVs, functional characterization of missense variants is crucial for novel genetic disease discovery. Overall, this thesis contributes to the field of energy metabolism defects, providing new insights that could lead to improved diagnostic accuracy, better patient management, and discovery of novel genetic diseases. The research fills crucial gaps in the existing knowledge and sets the stage for continued exploration in the genetic landscape of energy metabolism defects.Item Open Access Culture and Perception: Cultural Variation in Cognition and Self-Perception in European Canadians and Mongolians.(Spring 2025) Bayart-Od, Tsolmon|Department of PsychologyStudies in cultural psychology have reported cultural variations in cognition and perception between Eastern and Western cultures. However, recent studies have given serious consideration to the "WEIRD" discourse, emphasizing the necessity of data from cultures that have been underrepresented. The current research focuses on Mongolians, representing Central Asia's nomadic pastoral culture, and contrasts them to European Canadian counterparts, representing Western sedentary cultures. Participants engaged in existing cognitive and perceptual tasks, which included (1) the framed line task, (2) the causal attribution task, (3) the self-inflation task, (4) the engaged/disengaged emotion task, (5) the culture of honor questionnaire, and (6) self-construal measures. The results indicated that the holistic tendency among Mongolians is higher than that of European Canadians. Still, the self-assertiveness was generally as strong as their European Canadian counterparts. The current study succeeded in gaining compelling patterns of findings that depict nomadic-pastoral people’s psychological minds in a limited number of existing findings. Finally, we discuss that the unique Mongolian patterns of independence and interdependence with holistic cognitive style may play an important role in portraying the nomadic mind and further developing cultural psychological theory beyond the East West dichotomy.Item Open Access Solidifying AI-enabled Systems via Verification, Testing, and Monitoring(Spring 2025) Xie, Xuan|Department of Electrical and Computer EngineeringIn the information era, Artificial Intelligence (AI)-enabled systems are ubiquitous due to their scalability, cost-effectiveness, and the availability of diverse operation environments. They can empower the automation of tasks, analysis of data, and recognition of diverse patterns. However, their trustworthiness, e.g., fairness, safety, and truthfulness, also encounter enormous challenges when deployed in the real-world environment. Therefore, how to ensure and enhance the trustworthiness of the AI-enabled system is of vital importance in current research. Nevertheless, it is challenging to address the trustworthiness issues of AI-enabled systems due to their nondeterminism and data-driven nature. Towards mitigating the threats, in this thesis, we address the trustworthiness challenges of AI-enabled systems via trustworthiness assurance techniques, i.e., verification (formally proving that the system satisfies the specification), testing (finding defects or abnormal behavior of the system), and monitoring (real-time tracking and analysis of the system). We aim to design and build advanced trustworthiness assurance techniques to improve the reliability and robustness of practical AI-enabled systems. In the first part, we develop a novel method for computing fairness scores for AI-enabled systems and explicitly recognizing discriminating samples. By reducing dependency fairness verification to the safety specification, we find discriminating samples using well-established safety verification techniques. Furthermore, using four iterative region refinement techniques—random-based, saliency map-based, important neuron-based, and "greedy-based—we present a counterexample-guided fairness analysis. Our empirical analysis demonstrates that the method allows for scalable, effective fairness calculations and successfully handles bias questions. In the second part, we provide a model-based safety analysis approach for AI-enabled systems. In order to improve the efficacy of safety analysis, we first abstract the system as a Markov Decision Process (MDP), offering a representative model. We create two techniques for safety analysis using this abstract model: offline model-guided falsification and online safety monitoring. The evaluation’s findings demonstrate that our method successfully detects falsifying inputs and safety monitoring. In the third part, we present a set of multi-level testing coverage criteria for large language models (LLMs). Attention-based coverage, neuron-based coverage, and uncertainty-based coverage are the three different categories of criteria that we include. We apply these criteria to coverage-guided testing and test prioritization, two real-world scenarios. The usefulness and practical values of these criteria in improving model testing and assessment are validated by experimental outcomes. In the final part, we present a comprehensive benchmark study specifically designed to assess online defect detection methods for LLMs across various domains. This benchmark provides a foundational framework for the advancement and refinement of online defect detection techniques. Our study begins with an initial investigation showing how defects can arise early in the generation process, highlighting the critical role of online defect detection. The benchmark includes a wide range of analysis methods, LLMs, datasets, and evaluation metrics, enabling a systematic and detailed evaluation of the leading online defect detection methods. Furthermore, we introduce simple yet effective hybrid approaches that combine the strengths of various individual techniques to enhance overall detection performance. In conclusion, this thesis offers important developments that improve the trustworthiness of AI-enabled systems using advanced trustworthiness assurance methods, such as verification, testing, and monitoring. By addressing essential issues in this area, their contributions set the stage for the creation of more reliable and promising methods for enhancing the trustworthiness of AI-enabled systems.Item Open Access Web Scraping Methods to Assess Injury and Illness Trends in the National Hockey League(Spring 2025) Pinkoski, Adam|School of Public HealthReturning to play following an abrupt cessation of activity is a known risk factor for athletic injury (Sclafani & Davis, 2016). The National Hockey League (NHL) saw an unprecedented disruption to the competitive calendar due to the COVID-19 pandemic in March of 2020 (Zucker, 2020) and the impact of said disruption on injury and illness in the NHL is largely unknown. Given the nature of competition, where athletes are exposed to the highest risk sporting exposures (McKay et al., 2014), and the public interest in player health, injury data from internet-based public sources are an attractive option for sports-medicine-based research (Blond, Blond, & Loscalzo, 2021; Cahill et al., 2022). Significant variability in methodology, and thus results, exists between studies that use publicly obtained data (POD) (Inclan et al., 2024; Krüger et al., 2023), suggesting a need to standardize and operationalize methodology for its use. One potential source of variable results could stem from the NHL’s flexible injury disclosure policy that affords teams discretion if they feel disclosure may negatively impact a player’s physical wellbeing when they return to play (National Hockey League & National Hockey League Players' Association, 2013; Strong, 2024). Undisclosed events that result in time loss are rarely considered in sports-medicine research that use POD. The purpose of this thesis project was to i.) investigate the impact of an abrupt cessation of play in the NHL on injury and illness, ii.) to operationalize data scraping methods in a sports-medicine context, and iii.) quantify the bias introduced through the inclusion (or exclusion) of undisclosed events on time loss in the NHL. Strengths and limitations of web scraping methods were described in addition to providing step by step instructions in Python version 3.10.4 for how to access data pertaining to time loss in professional sports in a replicable fashion. Using a retrospective cohort of all NHL players between the 2016-17 and 2023-24 seasons, public access data of events resulting in time loss were collected. All data was collected using custom built replicable methods in Python. Burden of events was assessed through incidence and severity outcomes, and events were broken down into regional categories (upper body, lower body, head, core, non-game related injuries, illness and undisclosed). Inter- and intra-seasonal trends were investigated by adjusting for season, stage of season completion, player profile, playoff-competitive team or not, and pre- or post-pandemic seasons. Statistical analysis included Poisson and Negative Binomial Regression, with significance set at P < .05. Undisclosed events were more likely to be reported in the last fifth of the season (P < .001) and more common for higher profile players (P < .001), regardless of the stage of the season. Severity of undisclosed events was highly variable between seasons and did not show any significant trends over season duration. Exclusion of undisclosed events has the potential to significantly under-report incidence of injury and illness (P < .001). Incidence rate ratio (IRR) for illness peaked in December 2021 (IRR = 62.46; 95% CI 13.65 to 285.91). Incidence of upper body injuries was significantly higher in 2020-21 (IRR = 1.70, P = .001) and 2021-22 (IRR = 1.40, P = .044) compared to pre-pandemic seasons (Incidence = 17.58 injuries / 1000 player-hours). Injury incidence increased as the 2022-23 season progressed (P = .004); injury incidence was stable across all other seasons.Item Open Access Exploring MPT63-Derived Lipopeptides as Prophylactic and Therapeutic Vaccine Candidates against Mycobacterium tuberculosis Infection(Spring 2025) Sharma, Diksha|Department of SurgeryTuberculosis (TB) is an infectious disease that caused an estimated 1.25 million deaths globally in 2024. Mycobacterium tuberculosis (Mtb) is the etiological agent of TB and is responsible for the global burden of the disease. The emergence of multi-drug-resistant (MDR-TB), extensively drug-resistant (XDR-TB), and totally drug-resistant (TDR-TB) strains in recent years, along with the toxic side effects of the current treatment regimen, lengthy treatment duration, poor patient adherence, and additional challenges posed by HIV co-infections, has made it increasingly difficult to treat afflicted patients. Furthermore, the widely used Bacillus Calmette-Guérin (BCG) vaccine provides variable protection against the disease and is ineffective at preventing pulmonary TB in adults. Therefore, given the rising number of TB cases and the limitations of current treatment and vaccine options, there is an urgent need to explore new and innovative vaccine candidates that can mediate infection control through enhanced stimulation of protective host immune responses. Animal studies have shown that the culture filtrate of Mtb is rich in secretory antigens, such as MPT63, which exhibit vaccine potential. In this study, we developed an MPT63-derived synthetic lipopeptide construct to investigate its efficacy as a prophylactic and therapeutic subunit vaccine. The MPT63 lipopeptides (LPs), spanning the full-length sequence of the MPT63 antigen, were divided into Pool 1 and Pool 2 to assess potential differences in immune responses elicited by each pool. The aim of the study was to enhance the functionality of effector and antimicrobial cellular immune responses to reduce bacterial burden in the lungs, liver, and spleen of infected BALB/c mice. BALB/c mice were first administered intranasal immunization for the prophylactic immunization experiments, followed by infection with the H37Ra strain of Mtb via the intravenous route. The results from these experiments provided insight into the differential expression of T cell subsets, revealing that Pool 1 LP immunizations promoted an increase in regulatory cytotoxic T cell and regulatory helper T cell populations. In contrast, Pool 2 LP immunizations led to a robust production of effector cytotoxic T cells and antimicrobial helper T cells. Pool 2 LP immunizations also showed a trend toward reduced bacterial burden compared to both the control and Pool 1 LP-immunized groups. Both pools induced significant splenocyte proliferation in the absence of active TB infection, though no such significance was observed in the presence of active TB infection. Histological studies revealed that immunization with either Pool 1 or Pool 2 LPs resulted in reduced lung damage compared to the control (PBS-immunized group), with consistent immune cell infiltration across all groups. In the therapeutic experiments, the mice were first infected with the M. avium strain of Mtb via intravenous injection, followed by intranasal immunizations. Splenocyte proliferation analysis showed that Pool 2 LP immunization led to significant splenocyte proliferation compared to the control. In contrast, Pool 1 LP immunizations did not result in substantial splenocyte proliferation in the therapeutic disease model. Additionally, there was a trend toward reduced bacterial burden in the lungs, liver, and spleen of Pool 2-immunized mice compared to both the Pool 1 LP and control groups. Our study demonstrates that MPT63 lipopeptides from Pool 2 hold promise in generating effective cellular immune responses in mice's lungs, spleen, and liver when administered as prophylactic and therapeutic vaccines. These findings provide a strong foundation for future investigations into the potential of MPT63 lipopeptides as a vaccine candidate against Mtb.Item Open Access DATA PROCESSING AND CHEMOMETRIC STRATEGIES FOR METABOLOMICS AND EXPOSOMICS STUDIES(Spring 2025) Giebelhaus, Ryland Todd|Department of ChemistryMetabolites are small molecules (< 1,500 Da) produced or used during metabolism, typically involved in or produced from biochemical reactions in organisms. Metabolomics, the study of all metabolites in a living system, is one of the fastest growing fields within analytical chemistry, owing to its power to study small molecule metabolism, exposures, and physiology across all domains of life. Exposomics, the study of all exposures an organism experiences, is a rapidly growing subfield of metabolomics. The data generated from metabolomics and exposomics experiments is incredibly rich; however, it is also extremely complex. Processing data from these experiments remains a considerable challenge, and presents a bottleneck preventing these technologies from becoming more widespread in research. Current data tools for processing metabolomics data often have numerous parameters to optimize, yield inconsistent and irreproducible results, and require years of experience to use. This thesis will focus on the development of new data processing tools, workflows and strategies for processing metabolomics data, particularly pertaining to metabolomics data collected by gas chromatography mass spectrometry (GC-MS), comprehensive two-dimensional gas chromatography mass spectrometry (GC×GC-MS), and nuclear magnetic resonance (NMR). GC×GC-MS is the most powerful platform for performing metabolomics analyses, owing to its superior peak capacity, chromatographic resolution, improved sensitivity, and higher quality mass spectra. First, the development of two novel algorithms for the identification of regions of interest within GC-MS and GC×GC-MS chromatograms is presented. These algorithms provide a convenient preprocessing step for deconvolution by identifying regions of the chromatogram which contain chemical components, agnostic of peak shape. Both algorithms require minimal user inputs, reducing biases introduced during the optimization of hyper parameters. Next, the nature of GC-MS and GC×GC-MS data is explored in the frequency domain. Through this study, I identified that common electrical noise is present in GC×GC-MS data, increasing the noise in the system. I also noticed characteristic patterns in the frequency domain corresponding to modulated chemical information, which is unique to GC×GC-MS data. I developed two algorithms, one which removes the electrical noise, and the other which exploits the modulated data to increase the signal intensity. This improved the quality of the data without degrading the chemical information contained within. Two studies are detailed which explore the use of machine learning to interpret data collected from low field NMR instruments. Low field NMR instruments are often considered too low resolution for practical use in the chemistry laboratory. In the first study, I compared the predictive capability of two machine learning models trained on low field NMR and high field NMR for the task of authenticating samples of extra virgin olive oil. In this study, I found both models had comparable performance, which demonstrates low field NMR data is equally as useful for training predictive models as high field data. In the next study, I explored the performance of regression models trained on low field NMR data for quantifying adulterant oils spiked into extra virgin olive oil. These regression models had comparable performance to other similar techniques reported in the literature. Finally, preliminary results are presented from a large exposomics cohort study which aims to investigate the impact of prenatal cannabis exposures on the mother and infant’s metabolism. Both passive air monitor and urinary exposomics samples were analyzed with GC×GC-TOFMS. In these preliminary results, no cannabinoids or their metabolites are detected in the mothers’ urine. This is likely because these metabolites are in a chemical form which is not GC×GC-MS amenable. Additionally, the use of feature selection followed by machine learning was explored to attempt to predict the infants’ sex using the metabolite profile of the mothers’ urine. The work outlined in this thesis aims to increase the uptake and use of metabolomics and exposomics in research laboratories by improving how data is processed. I believe metabolomics and exposomics can become an indispensable tool for countless scientific inquiries throughout the 21st century and beyond, but for this to happen, practitioners of these fields need data tools which provide consistent and dependable results with minimal optimization and user intervention. These tools and workflows lay the foundation for developing more simple and reliable methods for processing and interpreting metabolomics and exposomics data.