Digital Commons Network^™

Timing, Targets, And Teaching: How Employee Help-Seeking Influences Downward Knowledge Sharing, Nicholle E. Kovach

Theses and Dissertations (Comprehensive)

Knowledge sharing between managers and employees is critical for employee development and organizational performance. However, managers differ in whether they share knowledge, and in the type of knowledge shared. While solution-oriented knowledge offers immediate answers to improve short-term performance, process-oriented knowledge promotes long-term learning and employee development. The purpose of my dissertation is to investigate factors that influence managers’ knowledge-sharing decisions.

I conduct two studies to investigate my predictions. In Study 1, I examine how the timing of employee help-seeking requests, the source of performance targets and employee historical performance influence the type and quality of managers’ knowledge-sharing responses. Drawing …

Prediction Of Continuous Amyloid Positron Emission Tomography With Fluid Measures Of Phosphorylated Tau And Β-Amyloid, Niklas Mattsson-Carlgren, Linda Karlsson, Weizhong Tang, Kaj Blennow, Henrik Zetterberg, Randall J Bateman, Suzanne E Schindler, Nicolas Barthelemy, Sebastian Palmqvist, Erik Stomrud, Shorena Janelidze, Oskar Hansson

2020-Current year OA Pubs

Brain amyloid-β (Aβ) pathology is a core feature of Alzheimer disease (AD) and can be quantified using positron emission tomography (PET). Cerebrospinal fluid (CSF) and plasma biomarkers detect abnormal Aβ, but it is unclear to what degree they can predict quantitative Aβ-PET. We explored plasma and CSF biomarkers in relation to Aβ-PET in the BioFINDER-2 study (N = 1053), and the BioFINDER-1 study (N = 238). We developed a machine learning pipeline to predict Aβ-PET using CSF and plasma measures. The best models achieved R

Mapping Climate Risks & Building Resilience: A Participatory Approach To Harvester Safety In Kakisa, Nwt., Susan Kerubo Ombwori

Theses and Dissertations (Comprehensive)

The Ka’a’gee Tu First Nation (KTFN) community in the Northwest Territories is experiencing rapid environmental changes which are driven by climate change. These changes are threatening the community’s food security. The community is seeing a disruption to its traditional land-based food systems due to increasing climate risks such as unpredictable weather, thawing permafrost, wildfires, and flooding. These changes are reducing access to traditional foods and intensifying threats to harvester safety. Building on the existing relationship with the community through previous projects, this thesis examines the impacts of climate risks on the availability and access of the KTFN’s on the land …

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 …

Neural Correlates Of Cognitive Fatigue In Regular Cannabis Users And Non-Users: A Pilot Fnirs Study, Mariia Vistyzenko

Theses and Dissertations (Comprehensive)

Background: Cognitive fatigue impairs performance across multiple domains, yet how regular cannabis use affects fatigue responses remains unclear. This pilot study investigated neural and behavioural correlates of cognitive fatigue in abstinent cannabis users versus non-users.

Methods: Twenty-six participants (18 non-users, 8 regular cannabis users after 24-hour abstinence) completed cognitive tasks before and after a 60-minute Sustained Attention to Response Task (SART) designed to induce fatigue. Tasks assessed working memory (N-Back), cognitive flexibility (Wisconsin Card Sorting), psychomotor speed (Digit Symbol Substitution), sustained attention (Continuous Performance Task), inhibition (Stroop, Stop Signal), and motion perception. Functional near-infrared spectroscopy (fNIRS) continuously monitored prefrontal cortex …

Children's Peer Selection In Stem: The Influence Of Gender, Ethnicity, And Disability, Meagan Girard, Kim P. Roberts

Theses and Dissertations (Comprehensive)

The present study examined how children’s peer selection in STEM (science, technology, engineering, and mathematics) may be influenced by gender, ethnicity, and physical disability. Sixty-four children (ages 6-12) from elementary schools in Southwestern Ontario completed three tasks: a simulated peer selection task, an attribution of ability task, and a stereotype belief questionnaire. In the peer selection task, participants were repeatedly asked to select one peer from a set of AI-generated photographs showing children who differed by gender (male, female), ethnicity (White, Black, East Asian), and physical disability status (able-bodied user vs. nondisabled). The Peer Selection Task was based on the …

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., …

Exploring Leadership In A Changing Church, Tanya Varner

Theses and Dissertations (Comprehensive)

The present phenomenological study investigated the experience of leaders and leadership among active Lutheran clergy serving congregations in the Eastern Synod of the ELCIC in a time of change. Eleven rostered leaders of the Eastern Synod of the Evangelical Lutheran Church in Canada (ELCIC) were interviewed individually using a semi-structured interviews addressing leadership and changes in the church to facilitate the conversation. Participants also completed a participant questionnaire in advance of the semi-structured interview to make sure the sample was diverse in gender, years of ordination and geographical context of ministry. Participants were able to articulate what values and requirements …

Eeg Correlates Of Tactile Synchrony, Devon K. R. Gallagher

Theses and Dissertations (Comprehensive)

New research on the tactile system has suggested that cortical representations of body parts are not fixed, as previously thought, and are instead dynamically maintained through constant sensorimotor information and feedback. Within the somatosensory cortex (S1), the capacity for both permanent and temporary changes have been the topic of ongoing research. The current study aimed to corroborate whether 24 hours of a finger adhesion manipulation is sufficient to elicit behavioural and electrophysiological correlates from cortical reorganization of digit representations in S1, using a behavioural paradigm outlined by Kolasinski et al. (2016). Through electroencephalography (EEG) recording during a tactile discrimination task, …

Moral Identity And Cognitive Mechanisms In Moral Decision-Making, Zachariah I. Hamzagic

Theses and Dissertations (Comprehensive)

Moral identity can be broadly conceptualized as the degree to which an individual places moral values as directly relevant to their personal identity. A recently introduced developmental framework of moral identity argues that moral identity can be conceptualized as a lifelong goal. According to this theoretical framework, the moral identity goal (i.e., to be a moral person and engage in moral action) becomes stronger over the course of development by becoming more abstract (i.e., general), internalized (to satisfy personal ideals) and promotion (i.e., action) oriented. Additionally, the strength of the moral identity goal predicts moral functioning. To date there has …

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 …

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 …

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 …

" 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 …

Geovig And Purevig: Geometry-Aware Architectures For Efficient Computer Vision, Omar Ismail

Theses and Dissertations (Comprehensive)

Deploying deep learning models for medical image analysis on mobile devices requires a balance between inference latency, memory footprint, and delineating anatomical boundaries with high accuracy. While Convolutional Neural Networks (CNNs) and mobile Vision Transformers (ViTs) offer efficiency, they often struggle to model the irregular, non-local geometric structures inherent in biological tissues without incurring prohibitive computational costs. In this thesis, we introduce GeoViG (Geometric Vision Graph), an architecture that bridges the gap between efficient grid-based processing and explicit Geometric Deep Learning. GeoViG introduces a novel transition from high-resolution pixel grids to low-resolution dynamic graphs via a SpreadEdgePool operator, a geometry-aware …

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 …

Robust And Interpretable Medical Image Segmentation Via Retrieval And Mechanistic Analysis, Salma Ahmed

Theses and Dissertations (Comprehensive)

Medical image segmentation is a critical component of clinical decision-making, yet deep learning based segmentation models face persistent challenges. These models typically require large volumes of densely annotated data, exhibit strong sensitivity to domain shifts across scanners and patient populations, and lack explicit anatomical priors. Furthermore, despite continual architectural advances beyond fully convolutional networks, most segmentation models remain opaque, where they lack the granularity required for component-level analysis. As a result, when segmentation models fail, it is difficult to identify which internal representations are responsible, limiting developers’ ability to diagnose errors, improve robustness, or establish trust in clinical settings. Existing …

Impacts Of Burn Severity On The Hydro-Physical, Chemical And Thermal Properties Of Sub-Arctic Peat, Joshua B. Meyer Mr

Theses and Dissertations (Comprehensive)

Under current climate change, summer season in the boreal regions of Canada is becoming increasingly warmer and drier. This shift is driving increases in the frequency and intensity of naturally occurring wildfires and allowing access to areas not normally susceptible to fire such as wetlands. In peatland areas, these increasingly large fires can create complex burn scars, which contain a wide variety of different burn severities across different landcover types. This variety calls for a greater understanding of how varying fire intensity affects the hydro physical, chemical, and thermal characteristics of boreal peat. This study aims to deepen that understanding …

Investigation Of Mercury Bioaccessibility In Subsistence Fishes From The Canadian Subarctic, Kiran Mateo Sharma Mr

Theses and Dissertations (Comprehensive)

Fish consumption is the primary pathway for human exposure to methylmercury (MeHg), a global contaminant of concern known to cause adverse health effects. Fort Albany First Nation, a remote Indigenous community in northern Ontario that relies on fish for both subsistence and cultural practices, has expressed concern regarding the safety of local fish consumption. Community members and leaders have communicated several priorities for scientific research that are the foundation of this thesis. Specifically, consumers of wild-caught fish have asked how traditional cooking methods may affect mercury concentrations in fish, and how mercury concentrations in little-studied organs, such as liver and …

The Association Between Maternal-Fetal Medicine Physician Density And Pregnancy Outcomes, Tetsuya Kawakita, Rula Atwani, Misa Hayasaka, Lindsay Robbins, George Saade

Department of Obstetrics & Gynecology Faculty Publications

Objective

We sought to examine the association between maternal-fetal medicine (MFM) physician density and adverse pregnancy outcomes at the state level.

Study Design

This was a cross-sectional analysis of publicly available, state-level data from 2018 to 2021, including Natality, Multiple Cause-of-Death, and Fetal Death databases. The number of active MFM physicians per year was obtained for each state from the American Medical Association Masterfile. The primary exposure was the density of MFM per state, categorized into three groups: (1) low density (< 30 MFM physicians per 100,000 live births), (2) moderate density (30-59 MFM physicians per 100,000 live births), and (3) high density (≥60 MFM physicians per 100,000 live births). Our primary outcome was maternal mortality during pregnancy and up to 42 days postdelivery. Our secondary outcomes were pregnancy-related mortality up to 365 days postdelivery and stillbirth. We calculated adjusted incident rate ratios (aIRR) and average marginal effect (AME) with 95% confidence intervals (95% CI) using multivariable negative binomial mixed effects regression models.

Results

Overall, there were 14,792,743 live births, 3,440 maternal mortalities, 4,980 pregnancy-related mortalities, and 90,848 stillbirths included. The …

Adjunctive Technologies To Electronic Fetal Monitoring: Promise, Pitfalls, And Lessons Learned, Rebecca Horgan, George Saade

Department of Obstetrics & Gynecology Faculty Publications

Despite widespread use, electronic fetal monitoring (EFM) has not demonstrably reduced perinatal morbidity or mortality, and likely contributed to the rise in cesarean delivery. To improve its utility, a number of adjunctive approaches have been introduced over the past three decades, including fetal pulse oximetry, ST segment analysis (STAN), and maternal oxygen supplementation. Each intervention was supported by strong physiologic rationale, yet none achieved widespread clinical adoption due to inconsistent evidence of benefit and, in some cases, potential harm. This review critically evaluates landmark studies on EFM adjuncts, highlights the limitations that have impeded progress, and outlines emerging innovations, including …

Antihypertensive Medications And Risk Of Alzheimer's Disease: Evidence For Specific Medication Use, Osvaldo J. Laurido-Soto, Alejandra Camacho-Soto, Irene M. Faust, Kassu M. Beyene, Aaron Katz, Jordan A. Killion, Brad A. Racette

2020-Current year OA Pubs

No abstract provided.

Association Between Neighborhood Social Determinants Of Health And Stillbirth, Tetsuya Kawakita, Misa Hayasaka, Ann M. Harper, John Brush, George Saade

Department of Obstetrics & Gynecology Faculty Publications

OBJECTIVE:

To examine the association between neighborhood-level social determinants of health and stillbirth.

METHODS:

We performed a retrospective cohort study of deliveries that occurred at a gestational age of at least 20 weeks within a five-hospital system (2012-2022). Electronic health record data mapped to the Observational Medical Outcomes Partnership Common Data Model were geocoded using addresses at the time of delivery and linked to neighborhood health indices, which included the Area Deprivation Index (ADI), Maternal Vulnerability Index (MVI), and Social Vulnerability Index (SVI) at the Census tract level. Stillbirths were adjudicated by medical record review. Modified Poisson regression generated relative …

Mediating Effect Of Social Determinants Of Health Between Race And Phthalate Biomarkers In Pregnancy, Tetsuya Kawakita, Misa Hayasaka, Carole Barake, Trinity Soto, Jillian Fleming, Amir Lueth, Stevens Danielle, Alfred Abuhamad, Ann Pryzybylska, Elena Sinkovskaya, Kelly K. Ferguson, George Saade

Department of Obstetrics & Gynecology Faculty Publications

Introduction

Prenatal phthalate exposure is linked to adverse reproductive and developmental outcomes and is consistently higher among non‐Hispanic Black compared to non‐Hispanic White pregnant individuals, yet the factors responsible for these disparities are poorly characterized. We sought to quantify Black–White differences in repeated urinary concentrations of phthalate biomarkers during pregnancy and to estimate the extent to which neighborhood‐level social determinants of health (SDoH) mediate these disparities.

Methods

This secondary analysis used data from the Human Placenta Project Study, a prospective observational cohort study conducted at two academic institutions between 2016 and 2018. Eligible participants had singleton pregnancies, were recruited before …

Differential Impact Of Admission Type And Clinical Complexity On Diabetes Hospitalization Costs Among African American And Hispanic Patients In Southeastern Virginia, Ismail El Moudden, Asra Amidi, Reem Sharaf-Alddin, Michael C. Bittner, Qi Zhang

Department of Obstetrics & Gynecology Faculty Publications

Background

Diabetes mellitus (DM) imposes substantial healthcare costs with documented disparities among African Americans and Hispanic patients. To inform care delivery and resource allocation, this study identified hospitalization cost predictors among African American and Hispanic patients with diabetes in Southeastern Virginia.

Methods

We analyzed 6,011 hospital discharges from the Virginia Health Information database (2016-2020) for adults aged 18-85 with diabetes. Discharges were classified by Medicare Severity Diagnosis-Related Groups: DM with complications/comorbidities (DCC, n = 3,328), DM with major complications/comorbidities (DMCC, n = 1,518), and DM without major complications/comorbidities (DWO, n = 1,165). Because cost distributions were right-skewed (skewness 3.5-8.24), we …

Contribution Of Comorbidities And Pregnancy Complications To Severe Maternal Morbidity In The United States, Tetsuya Kawakita, Sora A. Jones, Natsume Furukawa, George Saade

Department of Obstetrics & Gynecology Faculty Publications

Objective: To quantify the extent to which rising rates of severe maternal morbidity (SMM) in the United States from 2016 to 2022 are attributable to increasing prevalence of maternal risk factors, including advanced maternal age, obesity, pregestational diabetes mellitus, gestational diabetes, chronic hypertension, and hypertensive disorders of pregnancy (HDP).

Methods: We conducted a retrospective cohort study using the Nationwide Readmissions Database from 2016 to 2022, representing more than 25 million weighted delivery hospitalizations. The primary outcome of SMM was identified with the Centers for Disease Control and Prevention's 21-condition algorithm; a secondary outcome excluded transfusion to improve specificity. Temporal trends …

Biomechanical Integrity Of The Female Pelvic Floor: A Comparison Of Military And Civilian Women, Vladimir Egorov, Peter Takacs, Vincent Lucente, Heather Van Raalte, Joy A. Greer, Noune Sarvazyan

Department of Obstetrics & Gynecology Faculty Publications

Introduction

The health of the pelvic floor depends on the integrity of its muscles, connective tissue, ligaments, and their innervation. The female pelvic floor may be more vulnerable to repetitive heavy loads in a military environment than the male pelvic floor because of anatomical and physiological differences. The study aim was to identify and explore possible differences in the female pelvic floor conditions between active military and civilian women with similar demographics.To identify and explore possible differences in the conditions of the female pelvic floor between active military women and civilian women with similar demographics.

Materials and Methods

Military active …

Importance Of Placental Evaluation In Pregnancies At High Risk For Placenta Accreta Spectrum: Expert Clinical Perspective, Rebecca H. Jessel, Alesha White, Hope Y. Yu, Amie L. Hollard, Meena Khandelwal, Carolyn M. Zelop, Jennifer Philips, Alireza A. Shamshirsaz, John C. Kingdom, Alfred Abuhamad, Christina L. Herrera, Pan American Society For Placenta Accreta Spectrum (Pas2)

Department of Obstetrics & Gynecology Faculty Publications

Background

Placenta accreta spectrum (PAS) is a leading cause of obstetric morbidity and peripartum hysterectomy. Rising cesarean delivery rates, advanced maternal age, and assisted reproductive technologies have increased its incidence. Early, standardized diagnosis is essential for multidisciplinary planning and improved outcomes, yet formal screening guidelines are lacking.

Objective

To raise awareness of the importance of antenatal screening for PAS, summarize key clinical and imaging risk factors, and propose a standardized mid-trimester ultrasound protocol for high-risk patients.

Methods

An expert panel convened under the Pan-American Society for the Placenta Accreta Spectrum (PAS2) reviewed available evidence, risk stratification models, and prior consensus …

Acute Fatty Liver Of Pregnancy And Fetal Fatty Acid Oxidation Disorders: A Systematic Review, Dante Varotsis, Sarah Araji, Rebecca Horgan, Jennifer E. Powel, Rodney Mclaren Jr., Brian Kirmse, Mona Makhamreh, Huda B. Al-Kouatly

Department of Obstetrics & Gynecology Faculty Publications

OBJECTIVE:

To evaluate the association between maternal acute fatty liver of pregnancy (AFLP) and fetal fatty acid oxidation (FAO) disorders and to define the clinical and genetic characteristics of mothers with AFLP and their fetuses affected by FAO disorders, we performed a systematic literature review of all reported cases of AFLP that underwent genetic testing for FAO disorders.

DATA SOURCES:

We searched PubMed, Ovid MEDLINE, Cochrane Library, CINAHL (EBSCO), Scopus, and ClinicalTrials.gov. Terms included were related to AFLP and FAO testing.

METHODS OF STUDY SELECTION:

We conducted a systematic literature review from inception through May 18, 2025, to evaluate the …

Considerations For The Analysis Of Urinary Environmental Chemical Concentrations During Pregnancy, Danielle R. Stevens, Kaleigh Hinton, Katie M. O'Brien, Jessie P. Buckley, Barrett M. Welch, Jason A. Watts, Antonia M. Calafat, Julianne C. Botelho, Elena Sinkovskaya, Ann Przybylska, George Saade, Alfred Abuhamad, Kelly K. Ferguson

Department of Obstetrics & Gynecology Faculty Publications

Background:

Pregnancy physiology may impact indicators of hydration, affecting exposure assessment in gestational studies with urinary chemical biomarkers.

Methods:

We aimed to characterize hydration and demonstrate the impact of different methods for standardizing urinary chemical biomarker concentrations on exposure descriptives in the Human Placenta and Phthalates Study (n = 303, 2017-2020), a prospective pregnancy cohort with eight study visits between 12 and 38 weeks of gestation. We assessed trajectories and predictors of hydration using urine flow rate (UFR) and specific gravity (SG). Likewise, we examined trajectories and predictors of mono-n-butyl phthalate (MBP), for which concentrations were unstandardized or standardized via …