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Cytonuclear Incompatibilities In Hybrid Systems: Oxidative Phosphorylation Capacity And Nuclear Marker Transmission Ratio Distortion In Hybrids Of An Introgressed Strain Of Parasitoid Wasp, Julie Kessler

College of Graduate Studies: Theses & Dissertations

Speciation is an evolutionary process resulting in the divergence of populations into reproductively isolated species, a key concept that supplies our planet with an abundance of biodiversity. Mechanisms for speciation center on obstacles to fertilization and include post-zygotic barriers, such as intrinsic deleterious interactions, that arise in hybrid systems where genetic variants are combined. Genes from separate parent lineages are often incompatible due to the co-evolution of paired genes within a singular species not matching their complement genes in another species, and the result is a reduction in fitness of the hybrid when these genes come together. The mitochondrial OXPHOS …

Flexible Membrane Electrodes For Use In High-Capacity Lithium-Ion Batteries, David A. Denemark

College of Graduate Studies: Theses & Dissertations

Wearable electronic devices require high-capacity flexible batteries to improve user comfort and increase usage time per charge. In this thesis, flexible lithium-ion battery (LIB) electrodes are prepared using a novel and scalable phase inversion method, embedding one-dimensional SnO₂ nanowires and double-walled carbon nanotubes within a porous polyacrylonitrile asymmetric membrane. The optimized electrode delivered an initial specific discharge capacity of 915.93 mAh g⁻¹, approximately 2.5 times greater than conventional graphite anodes, with 61.99% capacity retention after 45 cycles. The incorporation of a carbon mesh substrate further enhanced both electrochemical and mechanical performance, achieving 89.46% capacity retention after 45 cycles and a …

Female Athletes’ Mental Health Help-Seeking Experiences: Understanding The Impact Of The Coach-Athlete Relationship And Coach Sex, Verena Zaisberger

College of Graduate Studies: Theses & Dissertations

Mental health help-seeking remains stigmatized in the world of sports (Cosh et al., 2024). Evidence suggests that female athletes may prefer to disclose vulnerable topics to individuals of the same sex (Keil et al., 2023), including help-seeking (O’Keeffe et al., 2022). However, no investigations have explored how coach sex or the coach-athlete relationship may influence female athletes help-seeking experiences. This is despite the importance of coaches in promoting and facilitating mental health services utilization (Bissett et al., 2020). To further understand this topic, the aim of this study was to explore what female athletes’ mental health help-seeking experiences are under …

Validity Of The Polar Verity Sense Optical Armband And Iphone Accelerometer For Heart Rate Variability Assessment, Chinelo C. Chukwuma

College of Graduate Studies: Theses & Dissertations

The purpose of this study was to test the validity of the Polar Verity Sense optical armband and iPhone accelerometer (Kubois seismocardiography, SCG) against the Polar H10 across different body positions (for both devices) and measurement durations (for Verity Sense only) while accounting for skin pigmentation. Healthy young adults (n = 46) participated in simultaneous recordings in the supine, seated, and standing positions using the Kubios mobile application on separate devices. Verity Sense measurements were collected for both 1‑ and 5‑min durations, whereas accelerometer measures were 1 min. Skin pigmentation was quantified with the melanin index (M-index). For resting heart …

Concordance Of Fluorescence In Situ Hybridization, Whole-Exome Sequencing, And Chromosomal Microarray For Evaluating High-Risk Molecular Features In Meningiomas, Brenndan Crumley, Emilie Russler-Germain, Sonika Dahiya

2020-Current year OA Pubs

BACKGROUND: Meningiomas are the most common primary intracranial tumors, classified into three WHO grades based on histologic and/or molecular criteria. cIMPACT-NOW Update 8 underscores the increasing importance of molecular testing in grading and risk stratification, noting that morphologically WHO grade 1 tumors with concurrent 1p and 22q losses demonstrate clinical behavior comparable to WHO grade 2 meningiomas. This study aimed to assess the concordance of fluorescence in situ hybridization (FISH), chromosomal microarray analysis (CMA), and whole-exome sequencing (WES) in defining the molecular risk profile of meningiomas.

METHODS: A total of 113 meningiomas were analyzed by WHO grade to assess the …

Spatial Variation In Socio-Economic Vulnerability To Influenza-Like Infection For The Us Population, Shrabani S. Tripathy, Joseph V. Puthussery, Taveen S Kapoor, John R. Cirrito, Rajan K. Chakrabarty

2020-Current year OA Pubs

This study aims to quantify environmental health impacts and assess risk by understanding the disproportionate burden of infectious diseases, specifically Influenza-like Illness (ILI), across regions with varying socio-economic characteristics. We introduce a novel vulnerability-based approach to better understand the complex relationship between socio-economic factors and ILI burden. We develop a machine-learning-driven framework to assess and map state-level socio-economic vulnerability to ILI in the United States. A vulnerability index was created by integrating 39 diverse socio-economic and health indicators from the latest CENSUS. A Random Forest Regression model then weighed these indicators to quantify each state's vulnerability for the ILI values …

Immortalization And Characterization Of Schwann Cell Lines Derived From Nf1-Associated Cutaneous Neurofibromas, Hua Li, Angela Hirbe, Et Al.

2020-Current year OA Pubs

Neurofibromatosis type 1 (NF1) is an autosomal dominant condition in which patients are heterozygous for a disruptive pathogenic variant in the NF1 gene. The most characteristic feature of the condition NF1 is the neurofibroma, a benign, multi-cellular tumor which initiates when a cell of the Schwann cell lineage gains a somatic pathogenic variant of the other NF1 allele. Neurofibromas developing at nerve termini in the skin are termed "cutaneous" neurofibromas (cNFs), while those developing within larger nerves are termed "plexiform." Most patients develop cNFs beginning in late childhood or early adulthood, continuing throughout life at variable rates. Some patients may …

Nanoparticle Carriers Enhance The Prophylactic Antiviral Effects Of Dsrna In Vitro And Ex Vivo, Shayne Oberhoffner, Stephanie Dewitte-Orr, Starla Richardson, Leah Haile, Dominique Daniels, Erin Cooper, Aizah Ijaz, Janet Velasquez Perez, Mathilde Peruzzi, Bertrand Collet, Paul Craig, Kristof Jenik

Theses and Dissertations (Comprehensive)

Aquaculture now outpaces traditional capture fisheries as the world population and demand for sustainable protein sources increases. Wild and farmed species are increasingly susceptible to pathogen spread as global temperatures rise and stocking densities increase. Despite the devastating losses experienced by aquaculture due to viral infections, there remain few effective prophylactic antiviral therapeutics. Long double-stranded (ds)RNA is a uniquely viral molecule produced by nearly all viruses during their replication cycle, and its detection by salmonids like rainbow trout (Oncorhynchus mykiss) and chinook salmon (Oncorhynchus tshawytsha) leads to the establishment of a defensive antiviral state. Previous in vitro studies demonstrated a …

The Effects Of Environmental Complexity On Brain Development And Personality Expression In Western Hognose Snakes, Gokulan Nagabaskaran

Theses and Dissertations (Comprehensive)

There is growing interest in snake cognition, personality, and welfare as more snakes are kept as pets, yet little research has been conducted. The effects of enrichment and environmental factors have been well documented in other taxa, and recent evidence suggests that snakes may benefit in similar ways. This dissertation investigated the impact of environmental and social enrichment on personality expression, personality stability, and brain development. Western hognose snakes (Heterodon nasicus) were used as the model species, as they are a popular choice in the pet trade. This allows the research to be readily translatable to husbandry practices of many …

Adapting To Uncertainty: Effects Of Environmental Instability On Zebrafish Behaviour, Britney Sekulovski

Theses and Dissertations (Comprehensive)

This thesis addresses how animals cope with unpredictability by testing how environmental stability changes the behaviour of zebrafish (Danio rerio) in two complementary experiments. In Experiment 1, fish lived for three months in either a Dynamic environment (water temperature, feeding times, habitat complexity, group size, and membership fluctuated) or a Stable environment (all factors constant). Across seven behavioural assays, measuring individual behavioural differences, collective movement, social memory, and information use, Dynamic condition fish were found to be more sensitive to social cues and more likely to conform to recent social information, independent of the quality of the information …

Envisioning The Role Of Community-Owned Stores & Aligning Federal Food Policies: A Participatory Approach To Food Security And Food Sovereignty In Sambaa K’E, Denendeh (Northwest Territories, Canada), Narayan Subramoniam

Theses and Dissertations (Comprehensive)

Northern Indigenous communities have relied on traditional food systems for meaningful, nutritious diets since time immemorial. But many Indigenous communities in remote northern regions of Canada still face disproportionately elevated levels of food insecurity due to climate change radically altering the availability for traditional foods, colonial food policies imposing Western diets, and the high costs of transporting store-bought foods. Extreme weather events such as wildfires further isolate fly-in remote communities increasing both the costs of transporting store-bought foods and the difficulties of harvesting traditional foods. There are many examples of community-based initiatives for supporting traditional and locally grown foods, however, …

Beyond Hereditary Xerocytosis: Chronic Hemolysis Due To A Non‑Classic Piezo1 Variant With Sickle Cell Trait As A Potential Modifier, Daniel Üblagger Md, Emily Jacobson, Beamon Agarwal Md, Phd, Jacob Troutman Do

Fellows and Residents

No abstract provided.

The Kidney Connection: Sepsis In Hospitalized Lupus, Muhammad Usman Zafar Md, Syeda Haris Mustafa Zaidi Md, Ansar Aziz Md, Sejal Lakhani Do, Courtney Hill Do

Fellows and Residents

No abstract provided.

Nuclear Aurka-Driven Early Dissemination Of Breast Cancer Uncovers Opposing Roles Of Hif-1a And Hif-1b In Metastasis, Abha Maskey

Graduate Theses, Dissertations, and Problem Reports (ETD)

ABSTRACT

Nuclear AURKA-driven early dissemination of breast cancer uncovers opposing roles of HIF-1A and HIF-1B in metastasis.

Abha Maskey

Metastatic progression is the primary cause of mortality in the majority of solid tumors, including breast cancer (BC). The triple-negative breast cancer (TNBC) is the most aggressive BC subtype with the highest recurrence rates within 1-3 years post-diagnosis, and worst overall survival outcomes. Early distant recurrence of cancer is enabled by early disseminated tumor cells (eDTCs), yet the mechanisms of early dissemination remain poorly defined. Hypoxia-inducible factor 1 (HIF1) is a transcription factor normally induced under hypoxia to enable cell survival. …

Alzheimer's Disease Stage 1 And 2: Biology, Diagnostics, And Treatment, Suzanne E. Schindler, Sarah M. Hartz, Et Al.

2020-Current year OA Pubs

No abstract provided.

The Role Of Home Visiting In Addressing Postpartum Care Gaps: Evidence From A Large Community Sample, Aishwarya Vijay, Allison Kemner, Karen Hoerchler, Abigail Edwards, Jeannie C Kelly, Rachel G Tabak, Mark D Huffman, Zainab Mahmoud

2020-Current year OA Pubs

BackgroundMaternal mortality in the United States has doubled over the last two decades, primarily due to cardiovascular disease, with more than half of deaths occurring postpartum. Despite national calls to action, attendance at postpartum clinic visits remains low. The role of alternative care delivery strategies, such as home visiting, remains insufficiently studied.ObjectiveTo describe postpartum clinic visit attendance among participants in a large national home visiting program, identify sociodemographic and clinical factors associated with attendance, and examine how timing and duration of enrollment relate to postpartum follow-up.DesignWe conducted a retrospective cohort study of pregnancy episodes among mothers enrolled in the Parents …

Participatory Systems Modeling In Implementation Research: Exploring Benefits, Facilitators, And Future Needs, Natalie Riva Smith, Jennifer L Cruz, Jessica Gannon, Stephanie Mazzucca-Ragan

2020-Current year OA Pubs

BACKGROUND: Implementation science increasingly uses participatory systems modeling (PSM) approaches to handle the complexity inherent to implementation science issues. To support the process of integrating PSM with implementation science, we aimed to understand and explicate the benefits, facilitators, and future needs of applying PSM to implementation research.

METHODS: We conducted semi-structured qualitative interviews with 23 researchers (n = 18) and practitioners (n = 5). We purposively sampled participants and identified additional participants through recommendations. Interviews were inductively analyzed. Key concepts were identified via iterative description, comparison, and conceptualization.

RESULTS: Engagement with people in the system was typically focused in earlier …

Presidential Immunity: Before And After Trump, Thomas P. Schmidt

Vanderbilt Law Review

'All the officers of government," the Supreme Court said long ago, "from the highest to the lowest, are creatures of the law, and are bound to obey it." Despite that ringing and categorical language, however, the Court has held that the President-the "highest" and most powerful of all government officers-is "immune" from judicial oversight in several respects. Indeed, when the Court held last Term that former presidents are presumptively immune from criminal prosecution for officials acts, the dissenters warned: '`n every use of official power, the President is now a king above the law."

This Article unpacks the various presidential …

"If I Knew Then What I Know Now": Analyzing Online Narratives Of Regretful Parents, Marina Binti Mohd Hamdan

Graduate Theses, Dissertations, and Problem Reports (ETD)

This exploratory study seeks to understand the extent to which parenthood affects individual self-actualization by identifying the trade-offs, compromises, and sacrifices that parents make within the context of family life. Using a thematic analysis of 221 archived posts from the Reddit community r/regretfulparents, this study examines how social pressures surrounding parenthood may be related to experiences of parental regret. Specifically, it identifies two domains: pressures to be parents, including social norms, familial coercion, and interpersonal conflict, and pressures of parenting, including issues of labor, number of children, and challenging children. Across these domains, this study explores how tensions between personal …

Investigating The Impact Of Winter Exposure To Natural Environments On Perceived Health And Well-Being Using Geographic Ecological Momentary Assessment: A Case Study At Arrowhead Provincial Park, Faith M. Laing

Theses and Dissertations (Comprehensive)

This study examined how winter exposure to specific natural environments influenced perceived health and well-being outcomes using Geographic Ecological Momentary Assessment (GEMA) in Arrowhead Provincial Park. Studies performed in the wintertime are limited, as is our understanding of how specific park features and/or activities impact health and well-being. To address this, GEMA was used with a video component to capture participants’ real-time experience and emotional responses in specific park locations defined by polygon boundaries. Two surveys were administered through participants mobile devices, one being an in-situ engagement survey triggered by entering a bounded location, which included a video and …

Multivariate Quantile Autoregression-Mixed Data Sampling (Mvqar-Midas) Modeling Of Cost Of Living And Supply Chain Dynamics In Canada., Patrick Gbolonyo

Theses and Dissertations (Comprehensive)

In recent years, the rising cost of living as a result of persistent inflationary pressures, disruptions in the global supply chains, and changes in the macroeconomic landscape has become a critical topic of discussion. To address this, we move beyond a mean-based framework and employ a quantile regression approach. This allows the persistence of each series and the transmis- sion of shocks between the Consumer Price Index (CPI) (the total CPI which is a percentage change over the past 12 months), the Interest Rate (IR)(the target for the overnight rate), the New Housing Price Index (NHPI), and high-frequency supply chain …

Religious And Spiritual Struggles: The Stories Of Nigerian, Immigrant, Christian Women In Waterloo Region, Halima D. Fuller

Theses and Dissertations (Comprehensive)

ABSTRACT This research investigates religious and spiritual struggles among Nigerian, immigrant, Christian women in Waterloo Region. Twelve women settled in the region for six months to 11 years participated in the study. Qualitative methodology, narrative inquiry, and a storytelling paradigm informed the research. Semi-structured, in-depth interview questions were used to explore the experiences of religious and spiritual struggles. A meticulous review identifies a scarcity of literature on religious and spiritual struggles in the context of immigration. However, immigration challenges such as language barriers, precarious employment, and mental health issues are well-documented (Bauder, 2012; Beiser & Hou, 2016; Berry et al., …

Autism And Homelessness: An Intersectional Case Study In Kitchener-Waterloo, Ontario, Nicole J. Mcdonald

Theses and Dissertations (Comprehensive)

Homelessness is a growing crisis in Canada, with literature suggesting autistic traits as over-represented within this population. Literature addressing intersectional experiences of autism is emerging, however there are gaps in the research surrounding intersectional experiences of autism and homelessness. Research suggests that autistic individuals may be more vulnerable to experiencing homelessness and face difficulties in exiting homelessness. This qualitative case study utilizes a Disability Justice framework to explore intersectional autistic experiences of homelessness, social service usage, and suggests recommendations on improving support for autistic individuals at risk of and experiencing homelessness. Four autistic participants with experience of homelessness and accessing …

The Politics Of Survival: South-South Migration, Urban Informality, Governance, And The Food Security Nexus In Nairobi, Kenya, Zack Ahmed

Theses and Dissertations (Comprehensive)

This dissertation contributes to the scholarship on South-South migration by integrating food security into the analysis of urban governance and migrant livelihoods in Sub-Saharan Africa. While migration and development have been widely examined, their connection to food systems remains underexplored, particularly in urban settings where informality, displacement, and transnational mobility converge. The research addresses this gap by investigating how Somali migrants and refugees in Nairobi’s Eastleigh navigate food insecurity within overlapping systems of governance, inequality, and transnational exchange. It explores three dimensions: the structural and socio-economic determinants of migrant household food insecurity, the impact of the COVID-19 pandemic as a …

Identifying The Physical Activity Promotion Practices Of Obstetricians And Gynecologists: Patients With Endometriosis And Polycystic Ovary Syndrome, Allison P. Herman

Theses and Dissertations (Comprehensive)

Despite efforts to promote physical activity, many females in Canada do not meet recommended physical activity guidelines. For individuals with gynecological conditions such as endometriosis and polycystic ovary syndrome (PCOS), physical activity may aid in symptom management and improve daily functioning. Healthcare settings, including obstetrics and gynecology, represent an area of opportunity to promote physical activity among this population. This thesis aims to understand the physical activity promotion practices of Ontario-based Obstetricians and Gynecologists (OBGYNs) to patients with endometriosis and/or PCOS. A cross-sectional online survey was conducted to explore OBGYNs promotional practices and perceived factors influencing their engagement in physical …

Methylseleninic Acid Transformations In Nutrient Rich Water Containing Algae Exposed To Simulated Sunlight, Mikayla Cormier

Theses and Dissertations (Comprehensive)

Methylseleninic acid (MSA(IV)) is an organic form of selenium that has been suggested to be one of the most bioaccumulative forms of selenium in aquatic ecosystems. However, there have been no lab studies that confirm this, which is the reason this study was conducted. Once MSA(IV) and other bioavailable forms of selenium enter aquatic ecosystems, organisms such as algae take up these compounds which then bioaccumulate through the food chain. S. obliquus was exposed to 10 ppb MSA(IV) in 10% Bold’s basal medium (BBM) in a growth chamber to mimic environmental conditions over a 7-day period. Carbon traps and filters …

A Contribution To Constructing A Theory And Model Of Social Work Leadership, Cheri Darlene Bilitz

Theses and Dissertations (Comprehensive)

Few schools of social work provide formal leadership education and training for emerging social workers—the research topic under exploration was how social work leaders constructed their leadership style. The purpose of the study was to develop a model of social work leadership through understanding leaders’ journeys into leadership and the contextual factors that shaped their leadership. Participants shared the qualities they believed were paramount for leading today and into the future. Seeing schools of social work as leadership incubators for emerging social workers, participants shared their suggestions for scaffolded leadership curriculum. The methodological approach for this research study was constructivist …

" Who Am I Here?" Exploring The Racial Identity Development Of Chinese Adolescent International Students In Canada: A Constructivist Grounded Theory Approach, Wen Juan Song

Theses and Dissertations (Comprehensive)

Abstract

This dissertation explores the racial identity development and associated mental health challenges of Chinese Adolescent International Students (CAIS) in Canada, a population navigating complex intersections of race, age, migration, and belonging. Despite their growing presence in Canadian secondary education, CAIS remain understudied in both educational and mental health research, particularly in relation to racial identity development within Western, multicultural societies. Using a Constructivist Grounded Theory methodology, this study draws on in-depth interviews with twenty-five CAIS participants, including ten current high school students, three returnees to China, and twelve who remained abroad in post-secondary education or employment.  The study is …

Error-Driven Density Control For Compact Gaussian Splatting Under Sparse Supervision, Abdelrhman Elrawy

Theses and Dissertations (Comprehensive)

This thesis studies efficiency and stability challenges in Gaussian-splatting-based reconstruction under sparse supervision. In few-shot novel view synthesis, standard 3D Gaussian Splatting (3DGS) can overfit the limited training views and grow an unnecessarily large number of primitives due to limitations in its Adaptive Density Control (ADC) mechanism. This thesis introduces an error-driven reformulation of ADC that triggers densification using opacity gradients as a lightweight proxy for rendering error, and shows that such aggressive densification must be paired with delayed and conservative pruning to prevent destructive create--destroy cycles. When combined with depth-based geometric regularization, the resulting framework produces substantially more compact …