Faculty of Graduate Studies Online Theses

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ASSESSING THE ROLE OF BAF SUBUNIT VARIANTS IMPLICATED IN NEURODEVELOPMENTAL DISORDERS USING DROSOPHILA-BASED FUNCTIONAL ASSAYS
(2025-12-18) Edison, Abigail C.; Not Applicable; Master of Science; Department of Biochemistry & Molecular Biology; Not Applicable; n/a; Not Applicable; Dr. Aarnoud van der Spoel; Dr. Johane Robitaille; Dr. Francesca Di Cara; Dr. Jamie M. Kramer
Neurodevelopmental disorders (NDDs) are frequently caused by variants in genes associated with chromatin regulation, interfering with transcriptional programs that support normal neurodevelopment. These genes include subunits of the Brahma-associated factor (BAF) chromatin-remodelling complex. Functional assays in the model organism Drosophila can inform whether an NDD-associated variant alters the function of the encoded protein. Here, I employed a Drosophila assay to assess variants in the BAF subunit SMARCD1. Knockout of Bap60, the fly orthologue of SMARCD1, is lethal. The expression of human SMARCD1 rescues lethality, forming the basis for a ‘humanised rescue’ assay. I screened 22 SMARCD1 variants of uncertain significance and found a deleterious effect in seven, providing functional evidence that reclassifies the variants to likely pathogenic. Additionally, I developed alternative assays for the BAF subunits ACTL6A/B and SMARCA2/4. Overall, this work provides novel insight on the functional impact of NDD-associated BAF subunit variants, assisting in their clinical classification.
Access status: Embargo ,
INVESTIGATING THE INFLUENCE OF MICROWAVE-ASSISTED PYROLYSIS PARAMETERS ON ADSORPTION CHARACTERISTICS OF BIOCHAR
(2025-12-22) Gohel, Kamleshkumar; Not Applicable; Master of Applied Science; Department of Process Engineering and Applied Science; Not Applicable; NA; Not Applicable; Ghada Koleilat; Mohammad Saeedi; Khaled Benis
Growing attention to environmental sustainability and circular economy practices has promoted the valorization of agricultural and industrial by-products for resource-efficient waste management. This research converts Brewer’s Spent Grain (BSG), a lignocellulosic biomass waste constituting nearly 85% of brewing industry waste, into functional biochar (BC) as an adsorbent for dye removal from water. Microwave-Assisted Pyrolysis (MAP) was used to prepare BSG-BC, and microwave power, irradiation time, and H3PO4 concentration were optimized using Box-Behnken Design (BBD) and Response Surface Methodology (RSM). Characterization (FTIR, SEM, BET, CHNS, TGA) confirmed improved porosity, surface area, and functional groups; the optimized biochar showed thermal stability and BET surface area ~502.9 m2/g. Adsorption experiments with Crystal Violet (CV) and Orange-II (Or-II) showed PSO kinetics (R2>0.99) and Freundlich/Redlich-Peterson isotherms (R2=0.96–0.99), with capacities of 53.28 mg/g (CV) and 46.97 mg/g (Or-II). Fixed-bed columns agreed with batch results, supporting BSG-BC for batch and continuous wastewater treatment.
Access status: Open Access ,
VTSECURE: EARLY WARNING RANSOMWARE DETECTION AND REPORTING SYSTEM VIA VIRUSTOTAL FOR NON-EXPERT USERS
(2026-01-06) Ibekwe, TOBECHUKWU; No; Master of Computer Science; Faculty of Computer Science; Not Applicable; n/a; Not Applicable; Dr. Saurabh Dey; Dr. Malcolm Heywood; Dr. Nur Zincir-Heywood; Dr. Marwa Elsayed
Ransomware is a continuously growing cybersecurity risk to governments and organizations in critical sectors such as power grids, health care, and the banking/finance industry where data privacy and system availability are essential for daily operations. Unlike other commonly known cybersecurity threats, ransomware attacks will not only disrupt operations but also threaten data confidentiality and integrity. To combat ransomware and its harmful effects, early detection systems can be developed and used by organizations and everyday users to identify potential threats before they escalate, hence minimizing the likelihood of successful attacks. This thesis proposes an early warning detection tool that leverages and examines files and URLs for potential threats. This research aims to create a tool for non-expert users, alerting them to harmful websites using VirusTotal’s API. By notifying users before they access malicious websites or download infected files, this tool can help prevent attacks from being triggered in the first place.
Access status: Open Access ,
ADVANCES IN WELD DESIGN FOR HOLLOW STRUCTURAL SECTION CONNECTIONS
(2025-12-22) Newcomb, Benjamin; Not Applicable; Doctor of Philosophy; Department of Civil and Resource Engineering; Not Applicable; Scott Walbridge; Not Applicable; Andrew Corkum; Yi Liu; Kyle Tousignant
A research program involving experimental and finite element (FE) analyses was conducted to investigate effective geometric properties for the design of welds in hollow structural section (HSS) connections as “fit-for-purpose”. The reliability of weld effective length, le, formulae for welds in rectangular hollow section (RHS) and circular hollow section (CHS) connections was examined, and new design formulae for fillet and partial joint penetration (PJP)-groove welds were recommended. Experimental data from tests on RHS gapped-K, overlapped-K, T-, Y-, and X-connections under branch axial load(s) were analysed to assess the reliability of fit-for-purpose weld design in accordance with the European design code, prEN 1993-1-8:2021. Existing le formulae were evaluated in conjunction with the Directional and Simplified Methods of prEN 1993-1-8:2021, and minimum fillet weld throat thicknesses, tw, required to develop the capacity of a connected RHS branch were recommended. An experimental program was then conducted on PJP-groove welds in six transverse plate-to-CHS X-connections to verify new le formulae. Reliability analyses were conducted and design recommendations for fit-for-purpose welds in plate-to-CHS X-connections were provided in accordance with North American design codes (AISC 360-22 and CSA W59:24). An assessment of micromechanics-based ductile fracture criteria was conducted to verify an approach to predict the fracture load of welds in HSS connections simulated in FE software. Stress-strain (σ-ε) curves of weld and base metals were modelled using tensile coupon (TC) data, a post-ultimate material approximation was validated, and eight fracture criteria were calibrated using experiment results. Twelve large-scale experiments and 158 FE simulations were conducted to investigate the reliability of le formulae in CSA W59:24 for fit-for-purpose PJP-groove welds in CHS X-connections with large branch-to-chord diameter, d1/d0 (= β), -ratios. The results were supplemented with previous FE data to verify the reliability of proposed le formulae. The influence of chord “end effects” was also studied, and design formulae were recommended for welds in connections with 0.10 ≤ β ≤ 1.00.
Access status: Open Access ,
LEVERAGING AUGMENTED REALITY AND MACHINE LEARNING TO SUGGEST DIAGNOSES FOR COMMON SKIN DISEASES IN BLACK AFRICANS
(2025-12-24) Olaiya, Olamiposi; No; Master of Computer Science; Faculty of Computer Science; Received; n/a; Yes; Oladapo Oyebode; Mayra Barrera Machuca; RIta Orji
Skin diseases are widespread health conditions that affect people of all skin tones but are often underdiagnosed or misdiagnosed in individuals with darker skin due to limited representation in dermatological research and diagnostic datasets. This thesis presents SkinVista, an mHealth application that integrates Augmented Reality (AR) and Machine Learning (ML) to enhance skin health awareness and support the suggestive diagnosis of common skin conditions among Black African populations. A distinctive strength of this research is the direct collaboration with Black dermatologists, whose clinical expertise informed every stage of SkinVista’s design, model development, and evaluation. This collaboration ensured that the system is contextually appropriate and specifically aligned with the diagnostic nuances of darker skin tones. SkinVista leverages AR-based camera guidance to help users capture high-quality skin images, while an ML model trained on dermatological images representing darker skin tones provides instant diagnostic suggestions for conditions such as acne, eczema, ringworm, and keloids. SkinVista was evaluated in two phases: (1) a pilot study involving six participants, and (2) a main study with seventy-one participants. The pilot study identified considerations and refinements to the study procedures and the application itself. Feedback showed high usability, with a mean SUS score of 85.0, and strong technology acceptance, with participants reporting high perceived usefulness (M = 4.33) and informativeness (M = 4.42) and also confirmed that the AR-guided capture workflow was intuitive and that it was feasible to conduct the study with a larger sample. Building on these refinements, the main study implemented the improved procedures with a larger sample, where participants interacted with the app, completed AR-guided image capture, received ML-based diagnostic suggestions, and evaluated the system using validated scales across usefulness, informativeness, usability, engagement, simplicity, and technology acceptance. Quantitative results showed high perceived usefulness and informativeness, with good usability ratings and positive behavioural intentions toward adoption. Qualitative feedback indicated that participants valued the app’s visual appeal, intuitive navigation, and educational content, while suggesting greater personalization and offline functionality. The findings demonstrate the potential of SkinVista to address diagnostic disparities through intelligent automation. This thesis contributes to Human-Computer Interaction (HCI) and digital health research by providing design insights for creating equitable, AI-driven healthcare tools that empower underrepresented populations and promote accessibility in dermatological care.
Access status: Open Access ,
REVIEW OF THE IMPACT OF ARTIFICIAL INTELLIGENCE ON PROJECT MANAGEMENT PRACTICES: INSIGHTS FROM INDUSTRY EXPERTS IN GHANA
(2026-01-05) Otoo, Daniel; Not Applicable; Master of Science; Business; Not Applicable; NA; Not Applicable; Joyline Makani, PhD; Paola Gonzalez, PhD; Kyung Young Lee, PhD
Advancements in artificial intelligence (AI) are reshaping organizational operations and strategic decision-making, with significant implications for project management (PM). As a core organizational function, PM plays a pivotal role in achieving corporate objectives through the successful execution of projects. The integration of AI into PM processes offers opportunities to enhance efficiency, optimize resource allocation, and improve decision-making. Despite growing scholarly interest, existing literature lacks a comprehensive framework that holistically examines AI’s influence across PM knowledge areas, process groups, and performance domains. Furthermore, methodological limitations persist, as prior studies predominantly employ singular approaches such as systematic literature reviews (SLRs) or quantitative surveys, while qualitative insights remain underexplored. Addressing these gaps, this study adopts a mixed-methods approach, combining an SLR with key informant interviews (KIIs) of industry professionals in Ghana—a region underrepresented in current research yet notable for its advancements in ICT adoption. Guided by the Task-Technology Fit (TTF) model and the Technology-Organization-Environment (TOE) framework, the SLR synthesizes findings from six reputable databases on the impact of AI on the project management body of knowledge (PMBOK) Guide, while KIIs provide contextual insights into practical challenges and opportunities. The research seeks to answer two primary questions: (1) How do AI-driven tools and techniques influence PM practices, including principles, process groups, and performance measures? (2) What challenges arise in implementing AI within PM in Ghana, Africa? Findings are expected to contribute theoretical and practical perspectives, offering actionable recommendations for organizations and future research directions (with four propositions). This study underscores AI’s transformative potential in PM and highlights the need for integrative frameworks to guide its effective adoption.
Access status: Embargo ,
PASSIVE ACOUSTIC LOCALIZATION AND TRACKING OF NORTH ATLANTIC RIGHT WHALES WITH A COMPACT HYDROPHONE ARRAY ON AN UNDERWATER GLIDER
(2025-12-23) MacGillivray, Michael; Not Applicable; Master of Applied Science; Department of Mechanical Engineering; Not Applicable; NA; Not Applicable; Dr. Ted Hubbard; Dr. Vincent Sieben; Dr. Mae L. Seto
North Atlantic right whales (NARW) are critically endangered (~380 remaining). Passive acoustic monitoring is used for detection and classification of the NARW vocalizations, but localization and tracking are limited. This thesis investigates the capabilities of localizing and tracking a NARW using an underwater glider equipped with a compact volumetric array (CVA). Multiple azimuth estimators and sound pressure level (SPL) ranging are tested in simulation and an in-water experiment. The novel azigram-KDE implementation yielded the most accurate and robust azimuth estimates, while SPL-ranging resulted in high estimation error due to source level and propagation loss uncertainty. A tracking framework was implemented, reducing in-water experiment Euclidean distance mean absolute error by 69%. The tracking framework was tested further in simulation using realistic NARW vocalization and motion behaviour, and improved localization accuracy for all cases. This thesis presents the viability and limitations of a single glider-CVA for marine mammal localization and tracking.
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UNDERPINNINGS OF CD8 T CELL ACTIVATION DURING IMMUNOSENESCENCE FOR CANCER IMMUNOTHERAPIES
(2026-01-05) Kumar, Vishnupriyan; Yes; Doctor of Philosophy; Department of Pathology; Received; Dr. Sue Tsai; Yes; Dr. Wenda Greer; Dr. Daniel Gaston; Dr. Jun Wang; Dr. Shashi Gujar
Immunotherapy has transformed cancer treatment, yet its efficacy remains variable, particularly in the context of aging, where immunosenescence impairs CD8+ T cell function. Aging is a major risk factor for poor responses to infection, therapy, and cancer. Critical gaps remain understanding how early CD8⁺ T cell activation states are regulated during aging. This thesis investigates the interplay between the CD38–NAD⁺ metabolic axis, early CD8⁺ T cell activation, and the ligandome of solid and hematological malignancies, that disproportionately affect older population. We first analyzed patients with pulmonary-only metastatic prostate cancer (PO-mPCa), a rare clinical cohort associated with favorable prognosis. Using an in-house developed pipeline, we defined the human leukocyte antigen (HLA) class I-restricted neoepitope landscape in these patients. This revealed a distinct neoepitope repertoire enriched in immunodominant peptides of optimal length, suggesting that unique HLA-neoepitope interactions may underlie their favorable disease course and providing a rationale for neoantigen-guided interventions. Next, we examined how immunosenescence reprograms early CD8⁺ T cell differentiation. We identified a transient pre-effector (TPE) (P4, CD44lowCD62Llow) that emerges rapidly after activation, functions within an innate-like timeframe, and bridges naïve to effector states. Strikingly, P4 frequencies declined with age, but residual cells were enriched for CD38 expression. Functional assays revealed that type I interferons can restore P4 effector capacity through IFNAR1-dependent bystander activation, rescue NAD⁺ and adenosine-mediated suppression. Finally, we investigated the ligandome of mantle cell lymphoma (MCL), integrating in vitro, in vivo, and patient-derived samples. Immune pressure and oncolytic virus therapy dynamically remodeled the HLA ligandome, dynamically altering predicted neoepitope candidates. Chemotherapy-treated patient samples further revealed reduced mutational and neoepitope burden, consistent with successful immune clearance. Overall, this thesis delineates how aging and therapy reshape the CD8⁺ T cell and tumor antigen landscapes, establishing the CD38–NAD⁺ axis and early P4 differentiation state as key modulators of immune competence. These insights provide both mechanistic underpinnings of immunosenescence and actionable strategies to optimize cancer immunotherapies across solid and hematological malignancies.
Access status: Open Access ,
ARISTOPHANES, NON-ATHENIAN DIALECT, AND INTER-POLEIS PEACE DURING THE PELOPONNESIAN WAR
(2025-12-30) Oliver, Emma; Not Applicable; Master of Arts; Department of Classics; Not Applicable; N/A; Not Applicable; Eli Diamond; Seth Sanders; Emily Varto
Aristophanes’ political stance remains an elusive scholarly question. Is he broadly anti-war in his plays, is he against the Peloponnesian War specifically, or is he simply critiquing Athenian democracy? What, if anything, is he advocating for throughout his works? Using a synthesis of various theoretical frameworks about comedy, ethnicity, dialect, gender, and politics, this project analyses Aristophanes’ use of non-Attic dialects of Greek and non-Athenian characters as tools to envision a Panhellenic image of Athens during an era when tension between poleis was at an all-time high. Though he is not prescribing plots like private peace treaties and sex strikes as solutions to the Peloponnesian War, the rational, ethnically diverse elements of Acharnians and Lysistrata in particular served both to remind his audiences that Athens, Sparta and their allies had fostered harmonious alliances in the past, and to prompt them to believe in the possibility for peace in the future.
Access status: Open Access ,
BOWHEAD WHALE BODY CONDITION IN A CHANGING ARCTIC ECOSYSTEM
(2025-12-24) Bazinet, Alexis; Not Applicable; Master of Science; Department of Oceanography; Received; Dr. Robert Lennox; Yes; Dr. Zoey Finkel; Dr. Eric Oliver; Dr. Hal Whitehead; Dr. Sarah Fortune
Climate-induced changes, particularly ocean warming and sea ice loss, may alter primary and secondary productivity in the Arctic Ocean, with cascading bottom-up effects for higher consumers. However, it is unknown how shifts in prey quality and quantity will impact the foraging success of bowhead whales (Balaena mysticetus) from the Eastern Canada-West Greenland (EC-WG) population. To assess the foraging success of the EC-WG bowhead whale population, I calculated body area index (BAI) as a metric of body condition using photogrammetric measurements obtained from 463 individuals. Aerial drone imagery (images and/or videos) were collected during summer over eight years (2016-2023) from Cumberland Sound (a foraging area), Nunavut. My objectives were to 1) compare the BAI of different age-sex groups to determine which EC-WG population segments were vulnerable, and 2) examine whether interannual variability in BAI was correlated with any environmental variables (e.g., sea ice conditions, major climate indices) over time. When length-based age-class data was pooled, I found that the Cumberland Sound habitat favoured a larger proportion of immature whales (juveniles and subadults), with younger (or shorter) age-classes (calves, yearlings, juveniles) in better body condition than older age-classes (subadults and adults). By combining measurements with biopsy (sex and epigenetic aging) results, I also confirmed that there was a skew towards male (44:22) and sexually immature (1+ to 23 years of age) whales. While the annual mean BAI varied within a small range of value (~31-33), fluctuations corresponded with changes in oceanographic conditions. Using generalized linear models, I found that improvements in body condition were positively correlated with lagged (1 to 3 years) environmental variables, including sea ice phenology (freeze-up and sea ice duration) and a positive summer North Atlantic Oscillation index, with the latter linked to increases in secondary productivity. Year was negatively correlated with BAI, suggesting a potential decline over the short timeseries consistent with a reversal in NAO phase. Overall, my findings provide insight about the body condition of the recovering EC-WG bowhead whale population, including previously under-represented age-classes, and how changes in health may occur on delayed timescales following episodic events.
Access status: Embargo ,
Microbial Community Assessment Via Environmental DNA: A Supplemental Method For Monitoring Finfish Aquaculture Impacts
(2025-12-23) Chen, Nan; Not Applicable; Master of Science; Department of Biology; Not Applicable; na; Not Applicable; Dr. Anaïs Lacoursière-Roussel; Dr. Robert Beiko; Dr. Julie LaRoche
With the increasing demand for fish consumption and the plateauing production of capture fisheries, aquaculture has become the primary supplier of fish for global consumption. However, the rapid growth and expansion of aquaculture have raised concerns about its environmental impacts, particularly those associated with organic effluents. With the accumulation of uneaten feed and feces under the fish pens, the benthic environment can quickly turn from oxic to anoxic, leading to the production of hydrogen sulfide, a toxic compound to the local ecosystems. To mitigate the impact of organic loading, various monitoring approaches have been applied and tested globally, mainly consisting of direct measurement of sulfide or employing biological indices, although each has noticeable limitations. As a result of the advancement of sequencing technologies, environmental DNA (eDNA) metabarcoding has become a promising tool for environmental monitoring. This thesis uses eDNA metabarcoding and metagenomics to characterize patterns in benthic microbial community composition associated with aquaculture activities, with the goal of supplementing the current monitoring practices. The results demonstrated that aquaculture is one of the factors that shape the microbial community. Chapter 2 developed and tested a supervised machine learning model using microbial eDNA amplicon sequence variants (ASVs) as a taxonomic-free environmental assessment tool. Although the model’s performance was hindered by extreme class imbalance, its integration with statistical indicator species analysis resulted in several indicator ASVs for aquaculture monitoring. Chapter 3 showed that organic effluent introduces fish-associated bacteria into the sediment communities and documented the first metagenome-assembled genome (MAG) of cable bacteria on the East Coast of Canada, possibly functioning as a sulfur oxidizer to remediate the aquaculture impact. Overall, this thesis demonstrated that microbial communities are sensitive to the aquaculture activities and have a strong potential to serve as a supplementary tool to the current aquaculture environmental monitoring practice.
Access status: Embargo ,
INVESTIGATING THE ROLE OF THE CHOLESTEROL TRANSPORTER, STARD3 IN ESTROGEN RECEPTOR-POSITIVE BREAST CANCER CELLS
(2025-12-22) Barter, Jena; Not Applicable; Master of Science; Department of Biochemistry & Molecular Biology; Not Applicable; n/a; Not Applicable; Dr. Paola Marcato; Dr. Neale Ridgway; Dr. Aarnoud van der Spoel; Dr. Barbara Karten
Breast cancer cells rely on tightly regulated cholesterol trafficking and growth factor signaling to support proliferation and migration. STARD3 is an endosomal cholesterol transfer protein frequently co-amplified with HER2, yet its biological role in estrogen-receptor positive (ER+) breast cancer remains unclear. Here, we investigated how STARD3 depletion affects proliferation, migration, and signaling in ER+ MCF-7 cells. Using a microRNA-based shRNA knockdown system, STARD3 expression was reduced at both the mRNA and protein levels. STARD3 depletion enhanced proliferation, increased CDK1 and GINS2 expression, and reduced the proportion of Ki67-negative (G0) cells. This proliferative advantage was not maintained when exogenous cholesterol availability was limited, indicating partial dependence. Despite enhanced proliferation, STARD3-depleted cells exhibited impaired wound-closure migration, suggesting a proliferation-migration trade-off. Elevated basal phosphorylation of focal adhesion kinase (FAK, Y397) implicates altered adhesion signaling. Together, these findings suggest that STARD3 maintains endosomal cholesterol homeostasis that supports adhesion-linked signaling in ER+ breast cancer cells.
Access status: Embargo ,
FOAM FRACTIONATION OF PEA (PISUM SATIVUM L.) PROTEINS & INTERACTIONS WITH RED BEET EXTRACT (BETA VULGARIS L.) TO IMPROVE STABILITY & FUNCTIONAL PROPERTIES
(2025-12-17) Kumar, Sonia; Yes; Doctor of Philosophy; Department of Process Engineering and Applied Science; Not Applicable; Dr. Valerie Orsat; Yes; Dr. Amyl Ghanem; Dr. Junzeng Zhang; Dr. Su-Ling Brooks
Peas (Pisum sativum) are a valuable source of vegan protein in Canada. They are preferred for their low production cost, good digestibility, low allergenicity, and gluten-free character. Common extraction methods can limit the functional performance of pea proteins by reducing their structural flexibility during processing, hence limiting their application in food systems. Red beets (Beta vulgaris L.) are also a valuable source of ingredients for the food industry. An example is betanin which is the main natural colorant in red beet extract (RBE), however it is susceptible to degradation under environmental and processing conditions. Herein, this thesis investigates the potential of foam fractionation to enhance the functional properties of pea proteins, and their subsequent interaction with compounds in RBE to enhance the stability, functional, antioxidant and antimicrobial properties of the complexes. Two-stage foam fractionation was used to recover and concentrate proteins from dilute pea protein flour (PPF) solution. With the first stage aimed for recovering the proteins, recovery percentage (R) of 86.66 ± 3.55 was attained, at the initial protein concentration (C) of 1.05 g/L, pH 4.5, air flow rate (V) of 800 mL, and liquid loading volume (L) of 4000 mL. The second stage was focused on the concentration of the PPF proteins, which resulted in the enrichment (E) of 5.83 ± 0.14 at pH 4.5, V of 300 mL and L of 1500 mL. Of all separated fractions, the second stage foamate showed most significant improvement of functional properties, such as solubility, foaming, emulsification, oil and water holding capacities. Interactions between pea protein isolate (PPI) and betanin in RBE on the stability of betanin were studied. Among the several pH levels investigated (pH 3-7), pH 3 exhibited an increased betanin retention of 55.53% at room temperature (21 ± 2 ℃) storage in PPI-RBE complex compared to the RBE control with a betanin retention rate of 4.31%. Under elevated thermal conditions (80 ℃), betanin retention rate in the PPI-RBE complex (12.5%) at pH 3 was higher than that of the RBE control, which exhibited a retention rate of 6.5%. The results showed that PPI-RBE interaction changed the PPI conformation, transitioning its structure from α-helical to β-sheets. Compared to the RBE control, the PPI-RBE complexes exhibited enhanced antioxidant activity and enhanced betanin retention following one-year of refrigeration storage. Foam-fractionated (foamed) PPF proteins and non-foamed PPF proteins were mixed with RBE to facilitate their complex formation. Molecular assessment analysis showed that non-foamed PPF proteins possess an α-helical structure, which is more pronounced in foam-fractionated PPF proteins. The interaction of non-foamed and foam-fractionated PPF protein with betanin in RBE resulted in transitions from α-helical to β-sheet structures. The foam-fractionated PPF-RBE complexes had a greater prevalence of β-sheets. The improvement of functional properties, stability, and antioxidant properties was likely due to the increase in β-sheets and legumin αβ disintegration in the foam-fractionated proteins. In general, the antimicrobial activity of these foam-fractionated PPF complexes was higher than RBE control with most inhibiting and bactericidal activity against gram-negative bacteria, specifically Escherichia coli. Thus, these complexes have the potential to be used as enhanced functional ingredients in food systems.
Access status: Open Access ,
Spider Seiðr Sympoiesis
(2025-12-20) Orvsson, Myrk; No; Master of Architecture; School of Architecture; Not Applicable; n/a; No; Catherine Scott; Joyce Hwang; James Forren
Anthropocentrism has blinded designers to the impact of their work on non-humans, while simultaneously limiting a rich source of inspiration. It is incumbent upon us to pursue kinder modes of co-existence with the more-than-human lives who we share a world with. This project’s eclectic experimentation combines methodologies from the disciplines of science, witchcraft, and design, pursuing a means for interacting with common cellar spiders (Pholcus phalangioides). Across a sequence of eight rituals, the contributing spiders and I produced a series of co-authored architectonic sigils. These objects, together with the tools and procedures necessary to create them, express a desire for kin-making between species, while reflecting architecture as a liminal zone and practice which connects humans and spiders. The processes and ethos informing these rituals are collected in a grimoire, a document which teaches the reader how to connect with and learn from spiders, both as embodied beings and symbolic figures.
Access status: Open Access ,
Causal Feedbacks and the Ecology and Evolution of Social Relationships in Northern Bottlenose Whales
(2025-12-29) Walmsley, Sam; Not Applicable; Doctor of Philosophy; Department of Biology; Not Applicable; Dustin Rubenstein; Not Applicable; Richard Connor; Sarah Fortune; Hal Whitehead
Social relationships are ubiquitous in the animal kingdom, though we are just beginning to understand their evolutionary origins and how they affect other aspects of biology. My thesis aims to understand the ecology and evolution of social relationships through an Endangered population of northern bottlenose whales (Hyperoodon ampullatus). Using field data spanning 37 years, my work provides new insights into the generality of key ideas in behavioural ecology. I begin by developing a new framework for quantifying bidirectional effects, such as co-evolutionary feedback or eco-evolutionary dynamics. This chapter bridges a major gap between theory and methodology in both ecology and evolution, highlighting new ways to analyze observational data. Next, I examine the structure of associations between individuals, finding new evidence of decades-long relationships among whales. These relationships are not shaped by kinship, in contrast to most studied mammalian societies. I then consider social connections across the lifetime, finding that older male northern bottlenose whales are socially isolated compared to their younger counterparts, mirroring declines in social connection seen in humans and other animals. Surprisingly, females appear to become more social with age, providing rare evidence that social ageing can be sex specific. I then apply methods designed to investigate causal feedback to the study of social behaviour in northern bottlenose whales. On a short-term ecological scale, I explore how social and spatial relationships in the whales change through time. In doing so I discover that sex and age influence space-use, with evidence of a potential nursery habitat. On a long-term evolutionary scale, I explore the phylogenetic origins of social complexity using a comparative model of social network structure. I find that life history and social structure co-evolved across the 34-million-year history of toothed whales, highlighting the central role of social relationships in shaping other aspects of biology. Together, this work illustrates how long-term ecological research and new methods for causal inference can be combined to understand the origins and functions of sociality.
Access status: Open Access ,
PostMom: An AI-Powered Culturally Tailored Persuasive App for Postnatal Support for Underserved Nigerian Mothers
(2025-12-24) Ogbonnaya-Okafor, Chinenye; Not Applicable; Master of Computer Science; Faculty of Computer Science; Received; N/a; Yes; Dr. Lizbeth Escobedo Bravo; Dr. Oladapo Oyebode; Dr. Rita Orji
The World Health Organization (WHO) recommends that pregnancy, childbirth, and the postnatal period should be positive experiences for all women, yet many underserved women in countries including Nigeria still lack adequate postnatal support. Limited access to postpartum care, cultural barriers, and inadequate health communication continue to hinder positive postnatal outcomes for Nigerian mothers. Although artificial intelligence (AI)-powered mobile health (mHealth) applications exist for maternal health, culturally appropriate interventions that integrate persuasive strategies for postnatal education and support remain limited, especially in low-resource contexts. This thesis presents PostMom, a persuasive mHealth technology that integrates AI techniques, including natural language processing (NLP), to deliver culturally appropriate postnatal health education and support for underserved Nigerian mothers. This work followed a three-phase, user-centered process. First, a review of 62 studies on AI in maternal health identified gaps in existing solutions and informed a set of persuasive strategies using the Persuasive System Design (PSD) model. Second, guided by these insights and consultations with four Nigerian medical doctors, a medium-fidelity prototype of PostMom was designed and evaluated through surveys and semi-structured interviews with 36 Nigerian mothers, whose feedback shaped design refinements. Third, a refined version of PostMom was developed and deployed in a one-week field study during which 70 mothers used the application for daily postnatal guidance and support. Results from validated usability and user experience assessments demonstrated good usability and positive user experience, while pre-post knowledge assessments showed that PostMom's persuasive features significantly improved participants' postnatal health knowledge (p < .001) and enhanced health information literacy. This thesis offers design recommendations for postnatal health applications, underscoring the importance of a human-in-the-loop design process. Overall, this work contributes to understanding the design and development of culturally tailored, AI-powered persuasive technologies for improving postnatal health knowledge, and enhancing postnatal care experiences for underserved populations.
Access status: Open Access ,
The Prevalence of Substance Use in Injured Off-Road Vehicle Drivers: A Systematic Review and Observational Study
(2025-12-15) Rheault, Grace; Not Applicable; Master of Science; Department of Community Health & Epidemiology; Received; NA; Not Applicable; Dr. Jill Hayden; Dr. Mark Asbridge; Dr. David Clarke
Background: Drug driving has become as common as alcohol-impaired driving in Canada and is a major public health issue. Substance use in the context of off-road vehicle driving (i.e., ATVs, snowmobiles, dirt bikes) has not been well-studied in Canada. The prevalence of acute substance use in injured off-road vehicle drivers across Canada is currently unknown. The aim of this study is to estimate the prevalence of acute substance use among injured off-road vehicle drivers in Canada. Objectives: This thesis includes two main studies and three key objectives. Part 1: Systematic Review and meta-analysis The first study involves a systematic review and meta-analysis, with the purpose of (1) estimating the prevalence of acute substance use in drivers involved in off-road vehicle crashes. Part 2: Observational Study The second study is a primary study of injured off-road vehicle drivers presenting to emergency departments across Canada. The two objectives of this study are: (2) to estimate the prevalence of acute substance use in injured off-road vehicle drivers presenting to emergency departments in Canada; and (3) to determine what factors (i.e. demographic, crash characteristics, regional variation) are associated with acute substance use in injured off road vehicle drivers presenting to emergency departments in Canada. Systematic Review Methods: Studies were identified from electronic databases and grey literature. Study selection, data extraction, and risk of bias assessment were completed by two independent reviewers. Descriptive statistics were used to report study characteristics. Random effects meta-analyses were used to report the overall pooled prevalence, and subgroup and sensitivity analyses were used to explore study characteristic effects and the robustness of results. Primary Study Methods: Employing data from the National Drug Driving Study, this study analyzed data from injured drivers presenting to 18 participating EDs across Canada who were in an off-road vehicle crash and had blood drawn for clinical purposes. Excess blood from clinical use underwent toxicology analysis to quantify the presence of impairing substances in the injured driver. Prevalence estimates of substance use in injured off-road vehicle drivers were reported overall, by substance type, by level of alcohol and tetrahydrocannabinol (THC), by number of substances and disaggregated by relevant covariates. Results: 20 publications comprising of 18 studies were included for review, with 2 sets of publications that had overlapping data, drawn from the same studies. Prevalence estimates ranged from 8% to 85%. The overall pooled prevalence estimate of substance use was 41% (95% CI: 28%-54%). There was significant heterogeneity across studies (Q = 3456.38, p < 0.001; I2=99.4%). Subgroup analyses found significant differences between studies using different data sources (coroner’s data: 57% (43%-71%) vs. hospital data (29% (6%-58%), and between non-fatally (29%, 95% CI: 9%-55%) and fatally injured drivers (56%, 95% CI: 43%-69%). The observational study included 473 injured drivers who met the inclusion criteria. Overall, 71% of tested drivers were positive for at least one impairing substance. Alcohol was detected in 38% of drivers, and 69% of those drivers were above the legal blood alcohol concentration (BAC) limit of 0.08% BAC. THC was detected in 17% of drivers. Central nervous system (CNS) depressants were detected in 31%, opioids in 14%, and CNS stimulants in 13% of drivers. About a third (32%) of drivers tested positive for more than one substance. Conclusion: These findings reveal that a large proportion of injured off-road vehicle drivers test positive for substances, which indicates a serious public health issue. Targeted interventions for at-risk populations and increased law enforcement are required to reduce impaired driving among off-road vehicle drivers.
Access status: Open Access ,
UNSOURCED RANDOM ACCESS WITH USER LOCALIZATION AND SENSING
(2025-12-14) Soltani, Roshanak; Yes; Doctor of Philosophy; Department of Electrical & Computer Engineering; Not Applicable; Dr. Ekram Hossain; Yes; Dr. Jason Gu; Dr. Alex Brodsky; Dr. Dmitry Trukhachev
Future wireless networks must support massive numbers of sporadic transmissions while meeting strict spectrum and energy limits. Unsourced random access (URA) provides a grant-free model in which devices transmit without pre-allocated resources and user identifiers and the receiver jointly detects user activity and decodes messages from a large number of users. This thesis advances URA by enabling sensing and localization within the communication process to build scalable frameworks that remain reliable and energy-efficient under heavy loads. It also contributes URA designs that tolerate relaxed synchronization and support longer payloads when needed. Amulti-antenna preamble–payloadURAarchitecture is developed that fuses compressedsensing (CS)-based activity detection with iterative multiuser detection (MUD), decoding, and channel refinement on Rayleigh fading channels. The design is extended to lowscattering regimes through channel models that account for array geometry, consistent with high-frequency environments. Building on this foundation, the thesis applies integrated sensing and communication (ISAC) principles. A location-based URA framework is introduced in which the base station (BS) localizes active users while detecting and decoding their data using only uplink signals. The method ties user transmission features to angle-ofarrival (AoA) and partitions space into sectors with sub-pool allocation and reuse to reduce collisions and complexity. Localization improves communication by providing spatial information that helps separate multiple packets. The concept is further generalized in the random-access procedure. The thesis also demonstrates environment sensing where user uplink signals act as opportunistic illuminators for multi-object sensing at the BS, revealing the synergy and trade-offs between sensing and communication. Some structural challenges of URA are also addressed. Scalability under timing uncertainty is achieved through a fully asynchronous URA design that removes slot and beacon requirements and performs sliding window timing acquisition together with MUD on the Gaussian channel. For longer messages a multi-segment URA structure is proposed that stitches decoded segments across consecutive slots and employs a dual preamble pool to identify the first segment and reduce collisions. Together, these studies show how URA can jointly deliver reliable data detection, user localization, and environmental sensing with high scalability, paving the way for intelligent and spectrum efficient random-access in future networks.
Access status: Embargo ,
A TRIPLE-MODALITY STRATEGY OF NKT CELL IMMUNOTHERAPY, ONCOLYTIC VIROTHERAPY, AND CHECKPOINT BLOCKADE FOR LUNG CANCER
(2025-12-15) Lukacs, Jordan; Not Applicable; Doctor of Philosophy; Department of Microbiology & Immunology; Not Applicable; Dr. Mansour Haeryfar; Not Applicable; Dr. Jeanette Boudreau; Dr. Graham Dellaire; Dr. Roy Duncan; Dr. Brent Johnston
Lung cancer is the leading cause of cancer-related deaths in Canada. Current standard therapies, such as chemotherapy, radiation therapy, or immune checkpoint blockade (ICB) are often ineffective on their own due to severe adverse effects and acquired drug resistance. Therefore, new treatments that are safer and more effective are needed. Recent clinical trials combining ICB with other therapies have demonstrated durable outcomes in some patients with lung cancer. Here I examined the efficacy of combining PD-1 checkpoint blockade with natural killer T (NKT) cell activation therapy and recombinant oncolytic vesicular stomatitis virus (VSV-ΔM51) expressing cytokines IL-12 (VSV-IL-12) or IL-15 (VSV-IL-15), or fusion- associated small transmembrane (FAST) proteins p14 (VSV-p14), p15 (VSV-p15), and p14endp15 (VSV-p14endp15). VSV-p14, VSV-p15, and VSV-p14endp15 demonstrated enhanced immunogenic cell death and killing capacity relative to the parental virus (VSV-GFP) in lung cancer cells, in vitro. Furthermore, VSV-FAST constructs induced PANoptosis and overcame the blockade of multiple programmed cell death pathways to effectively eliminate lung cancer cells. In a genetic mouse model of lung adenocarcinoma, the combination of VSV-p14, VSV-p15, or VSV-p14endp15 with NKT immunotherapy increased overall survival relative to untreated mice. Addition of PD-1 blockade to NKT immunotherapy and VSV-FAST constructs significantly extended the survival over untreated mice. Mixed delivery of VSV-p15 and VSV- IL-12, along with NKT immunotherapy and PD-1 inhibition, had the greatest increase in overall survival of all tested combinations. Maintenance therapy with multiple rounds of VSV-p15/NKT activation/PD-1 blockade also led to significantly enhanced overall survival rates in this model, however some female mice experienced adverse reactions to the treatment. Despite increases in overall survival and increased numbers of NKT cells in the lung and spleen, there were no significant differences in total tumor area or total number of other immune cell populations within the lungs of treated mice compared to untreated mice. We also observed increased VSV neutralizing activity in the serum of treated mice, suggesting potential challenges with repeated systemic VSV treatments. Collectively, our findings demonstrate that the combination of PD-1 blockade with NKT cell immunotherapy and oncolytic VSV-p15/VSV-IL-12 presents a promising strategy for the treatment of lung cancer.
Access status: Open Access ,
Spatial and Temporal Mechanisms Controlling Convection Over The Great Plains
(2025-12-15) Verevkin, Iaroslav; Not Applicable; Doctor of Philosophy; Department of Physics & Atmospheric Science; Not Applicable; Yanping Li; Yes; Thomas Duck; Glen Lesins; Ian Folkins
The central United States exhibits an anomalous summertime diurnal cycle of precipitation, characterized by an afternoon maximum over the Rocky Mountains that transitions to a nocturnal maximum over the Great Plains. This phenomenon, which remains a challenge for many numerical models, is governed by the interaction of processes spanning multiple scales. This thesis investigates the spatial, temporal, and dynamical mechanisms controlling this diurnal cycle through a comprehensive, climatologically-grounded multi-year analysis of satellite-derived precipitation data Integrated Multi-satellitE Retrievals for GPM (IMERG) and hourly meteorological analyses Rapid Refresh and Rapid Update Cycle (RAP/RUC). The research is presented in three parts. First, the spatial variation in the synoptic structure of convective systems is examined. The analysis reveals a distinct transition in dominant forcing mechanisms with distance from the mountains: convection in the “Near Plains” (west of 100◦W) is significantly influenced by mountain-initiated solenoidal circulations, while convection in the “Far Plains” is more closely associated with the dynamics of the Great Plains Low-Level Jet (GPLLJ). Second, the thesis investigates the diurnal evolution of vertical profiles of convection. A systematic diurnal shift from surface-based to elevated convection is identified, which consistently occurs as the nocturnal boundary layer stabilizes. This shift is linked to a threshold in the low-level lapse rate of approximately -4 to -5 K/km, providing a quantifiable metric for the influence of boundary layer thermodynamics on the convective mode. Finally, the thesis examines the climatological eastward propagation of rainfall. The analysis demonstrates that the diurnal, clockwise rotation of the GPLLJ’s wind vector drives a propagating pattern of low-level mass convergence across the plains. This mechanism is modulated by topographically-induced suppression of afternoon convection via enhanced convective inhibition (CIN), enabling the nocturnal, dynamicallydriven rainfall maximum to dominate.

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