Trent University

Amyloid fibrils are fibrous protein aggregates that arise from misfolding and self-assembly processes, collectively referred to as amyloidosis. These aggregates are strongly associated with incurable neurodegenerative disorders, including Alzheimer's disease (AD), Parkinson's disease, and Amyotrophic Lateral Sclerosis (ALS). Elevated levels of Reactive Oxygen Species (ROS) and dysregulated metal-ion homeostasis often impaired by environmental and lifestyle factors can induce oxidative stress that undermines cellular antioxidant defenses, which cause the amyloid formation and toxicity. This thesis investigates multiple amyloidosis models, emphasizing the contribution of metal ions and ROS to aggregation pathways, and evaluates the potential inhibitory or protective roles of cytokinin (CK) plant hormone.Chapter 2 focuses on Gelsolin amyloidosis, a hereditary condition driven by point mutations that promote aberrant amyloid formation. Using microscopic and spectroscopic approaches, this work characterizes the aggregation behavior of peptides derived from domain 2 of plasma gelsolin and secreted by muscle cells. Three peptides were studied: the wild-type(WT) sequence and two clinically relevant mutants, K184N and N187Y. Each variant exhibited distinct aggregation rates, reflecting mutation-dependent effects on self-assembly. Furthermore, two CKs Kinetin (Kin) and trans-Zeatin (tZ) were shown to modulate gelsolin aggregation, suggesting their potential as anti-aggregation molecules. Chapter 3 revolves on the aggregation properties of TDP-43 peptides associated with ALS pathology. Within the RRM I domain, two cysteine residues serve as key redox-active sites susceptible to oxidation. ESI-MS and spectroscopic methods were used to analyze three peptide variants: WT, a mutant (MT) in which cysteine were substituted with alanine, and WT-S, a disulfide-linked dimer. All variants displayed higher aggregation under mildly acidic conditions. CKs, Kin and isopentenyl-adenine (iP) showed antioxidant capacity and their influence on peptide stability. Chapter 4 investigates the effects of copper(II)-induced oxidative stress in C2C12 muscle cells and evaluates cellular responses to various CK forms. ESI-MS profiling identified 20 CKs in copper-treated samples and revealed 24 untargeted metabolites with significant level changes, indicating their possible involvement in metal-induced oxidative pathways. In conclusion, this thesis highlights the multifaceted roles of CKs in biological systems, particularly their potential to mitigate ROS overproduction, counteract metal-driven amyloidgenesis, promote fibril destabilization, and lessen oxidative stress.

Author Keywords: Amyloid, Anti aggregation, cytokinins, inhibition, Peptide aggregation, Protein aggregation

The objective of this thesis is to collect and analyse wild clay from the vicinity of previously identified and excavated archaeological sites near Pigeon and Rice Lakes, and comparing the characterized clay samples to archaeological pottery samples from the sites. The purpose of this research is to explore the resource exploitation in the landscapes around sites, and investigate the behaviours associated with resource exploitation and pottery manufacture. Through the application of X-Ray fluorescence spectrometry (XRF), each sample from four clay sources was analysed for its chemical composition, and compared to the chemical composition of Middle and Late Woodland Period pottery to investigate the similarities or differences between sources and finished items. The results demonstrated overlap between a source east of Rice Lake and pottery excavated from Chiminis-1 and Jacob Island-2.

Author Keywords: Clay Sourcing, Ontario Archaeology, Pottery, Resource Exploitation, Woodland Period, X-Ray Fluorescence Spectrometry

This thesis employs zooarchaeological, taphonomic, and spatial analysis to reconstruct subsistence behaviors of Middle Paleolithic Neanderthals using layer V of Abric del Pastor as a case study. Located in Alcoy, Alicante, Spain, Abric del Pastor is a cave shelter with occupation layers dated from MIS 5 through 3. The faunal assemblage is examined on two time scales: i) a longer time frame focused on large scale human occupation and use and ii) another, shorter time frame in an attempt to distinguish possible shorter anthropogenic events. The layer V assemblage is comprised of at least two occupation events, Occupation A and Occupation B. These are two relatively well-preserved anthropogenic accumulations dominated by medium sized taxa. In these occupations, the carcasses were likely transported from a separate kill site to the cave shelter to be processed and consumed. The taxonomic and taphonomic patterns uncovered in these occupation events are similar suggesting consistent behavioral patterns throughout Layer V. Ultimately, the faunal assemblage is typical of other MIS 5-3 rock shelters in the Iberian Peninsula. By examining the subsistence practices of layer V, dated to MIS 4, this work aims to fill a gap in the MIS 4 Iberian Peninsula literature and add to the conversation on how early hominins adapted to the changing climate.

Author Keywords: Abric del Pastor, Iberian Peninsula, Middle Paleolithic, Palimpsest, Time Perspectivism, Zooarchaeology

A key knowledge gap in aeolian transport research concerns the adjustment of saltation processes to the extreme conditions found within high-latitude regions. A series of wind tunnel experiments were carried out under full climate control and over a wide range in humidity. Particle entrainment and transport within shearing flows of varied wind speed were monitored over beds of varied temperature, and ice content to determine their affect on 1) particle trajectory, 2) saltation cloud height, 3) particle velocity, 4) surface erosivity, 5) mass transport rate and 6) vertical dust flux. Particles were found to have higher velocities over cold beds than dry beds. With a 3% increase in bed moisture content, a significant increase in particle velocity was measured. Fewer particles are ejected from a bed with moisture than a dry bed. The mass transport rate was measured to be 23% higher at -10 degrees Celsius compared to 30 degrees Celsius.

Author Keywords: Aeolian processes

Dissolved inorganic carbon in drainage waters is a direct measurement of carbon dioxide (CO2) removal from enhanced rock weathering (ERW) in soils. In this study, square metre scale field experiments (2021–2023) were conducted in Peterborough Ontario, Canada, each amended with kimberlite residues from Gahcho Kué Diamond Mine (Northwest Territories, Canada) or olivine powder at high application rates (100–400 t/ha). Porewater chemistry data, coupled with a water budget analysis derived from precipitation and soil moisture data, were used to quantify solubility trapping by amendment weathering revealing maximum rates of 0.04 t CO2/ha over 2 yr for olivine and 0.9 t CO2/ha over 3 yr for kimberlite. This research presents kimberlite mine wastes as an ERW feedstock alternative to basalt as projects scale-up and require more rock. Additionally, high dosage monitoring plots ensure detection of a CO2 removal signal in open systems and should be considered for large scale projects.

Author Keywords: CO2 removal, Enhanced rock weathering, Field experiment, Kimberlite, Mine wastes, Olivine

This thesis examines contradictions in approaches to fashion cataloging and exhibition by considering how the fashion artifact is used as physical evidence for public memory of the past. As a memorial practice and timekeeper, fashion demands a complex cultural understanding of artistic production, aging, and history. How does this understanding of fashion as a cultural index and narrative challenge our knowledge of history and the problems inherent in trying to produce a historical narrative through cloth? Where do we fall short in dress reconstructions and our understanding of time and aging through approaches to fashion and dressing? How do these considerations challenge cultural attitudes toward fashion's role in helping understand death and aging in the larger cultural lexicon? By addressing fashion's relationship to time and what might be termed the death aspect of dress as connected to bodies from the past, we allow for a less biased approach to historic fashion that will account for more regional, communal, and individual tastes in dress. This method of inquiry permits a more balanced understanding of dressing ideals across socioeconomic levels regarding garment production and reproduction. Continually addressing the personal in fashion reinforces the unique nature of each garment and its relationship with the body as part of fashion's corporeal register. Keywords: Fashion Artifact, Garment Production, Garment Reproduction, Reconstruction, Corporeal, Embodiment, Eastern Time, Historicism, Public Memory, Memorial, Aging, Western Time

Author Keywords: Corporeal, Embodiment, Fashion Artifact, Garment Reproduction, Historicism, Public Memory

Previous researchers have linked lower levels of stress and greater ability to mobilize energy toward a goal (self-motivation); confidence in their ability to complete/achieve a particular task or goal (self-efficacy), and ability to willfully control their thoughts, emotions and behaviour (self-control) to regular physical activity (PA). In an effort to provide further insight into the processes underlying regular PA researches have begun to explore the interplay among stress and multiple self-regulatory variables when predicting level of PA (i.e., intensity and duration). In line with this integrated approach the present study aimed to examine the interplay among self-motivation, self-efficacy, and self-control when predicting daily PA. The study was a correlational design with cross-sectional data on trait self-motivation and self-efficacy collected at baseline, and longitudinal data collected on stress, PA, state self-control, self-motivation and self-efficacy over a 2 day period. The results from the regression model (n = 418) revealed a negative indirect effect of stress on participants level of PA through its negative relationship with state multifactor self-regulation. This mediation effect appeared to be moderated by trait SE and SM. In conclusion, these results support the notion of a stress related depletion effect acting on individuals state self-regulatory resources which was associated with lower levels of PA (i.e. intensity and duration). However, the negative effect of stress appeared to be buffered by high levels of trait SE and SM.

Author Keywords: exercise, physical activity, self-control, self-efficacy, self-motivation, self-regulation

SOGIE refugee scholarship examines intersecting power relations, including race, ethnicity, gender, class, citizenship, and geopolitical location. A key intersection is how SOGIE claimants navigate the homonationalist apparatus of the Canadian refugee system, which constructs the identity category of an "authentic" SOGIE refugee as characterized by pure victimhood and passivity, based on a Western-exceptionalist notion of sexuality. Through a comprehensive literature review and Thematic Analysis of 30 publicly available SOGIE refugee decisions in Canada, this study identifies three primary assumptions about the "authentic" SOGIE refugee claimant: the Public/Private Discourse of LGBT Rights, the Linear, Progressive Narrative of SOGIE, and the Homocolonial Inclusion of LGBT Rights. Recognizing the limitations of "adaptive agency," this analysis centers the transformative potential of SOGIE refugee claimants' narratives in interrogating these assumptions through their "discursive agency," transcending the limitations of liberal notions of agency that operate within a dichotomy of resistance and compliance.

Lake whitefish (Coregonus clupeaformis) are ecologically, economically, and culturally significant across their range, yet little is documented about the species' spawning behaviour. Recruitment of lake whitefish has dramatically declined over the past two decades across many regions of the Laurentian Great Lakes, most notably in lakes Huron and Michigan, prompting research efforts to fill critical knowledge gaps in the life history of this species. Understanding the reproductive ecology of lake whitefish, including documenting aspects of spawning behaviour, may reveal clues about factors contributing to the declines. This study used fine-scale acoustic telemetry to characterize sex-specific movement patterns and habitat associations of lake whitefish during the spawning season. A VEMCO Positioning System (VPS) was deployed at an active spawning shoal in Georgian Bay (Lake Huron), with guidance provided by Saugeen Ojibway Nation members with local ecological knowledge about the shoal and the lake whitefish population. In the fall of 2020, 50 lake whitefish were captured and tagged at the spawning shoal; 28 of those fish were observed the following spawning season in 2021. A clear increase and decrease was observed in the presence of individuals in the study area over the spawning period. Both sexes moved into shallower waters at night and deeper waters during the day at rates of 0.162 m/h and 0.08 m/h, respectively. Decreased rates of movement and horizontal distance travelled were detected during the day leading up to a peak activity phase where 22 fish were present. At night during this peak activity phase, males moved 30.0% faster on average than females (0.204 ± 0.13 and 0.143 ± 0.10 m/s, respectively). This study provided a unique opportunity to work with local First Nations to understand lake whitefish spawning behaviour, providing insights into the reproductive ecology of a population undergoing concerning declines in recruitment and abundance.

Author Keywords: Coregonine restoration, Coregonus clupeaformis, Fine-scale acoustic telemetry, GLATOS, Spawning habitat, Two-Eyed Seeing

The prevalence of hypertension and mental illness among Black Canadians is a growing public health concern. There is a paucity of Canadian research exploring the lived experiences of Black individuals with both hypertension and anxiety, particularly in relation to how racism shapes access to healthcare. This study aimed to advance awareness and cultural understanding of systemic and institutional racism, with a focus on its impact on access to care. A qualitative design employing descriptive and interpretive phenomenology was used. Ten participants were recruited through purposive sampling. Data were collected via semi-structured interviews with Black individuals residing in the Greater Toronto Area (GTA). Key findings suggest that racial inequities and disparities continue to directly affect the quality of care received, with racism emerging as a persistent barrier. These findings underscore the need for culturally responsive, equitable care approaches to address the structural barriers faced by Black communities in Canada.

Author Keywords: anxiety, Black health disparities, healthcare access, hypertension, institutionalized racism, racial inequities in healthcare