YorkSpace

YorkSpace is York University's Institutional Repository. It supports York University's Senate Policy on Open Access by providing York community members with a place to preserve their research online in an institutional context.

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Recent Submissions

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    Synthesis and Characterization of Composite Textured Surfaces with Enhanced Tribological Responses on Icy Surfaces
    (2026-11-06) Zahmatkesh, Sara; Reza Rizvi
    Slips and falls on icy surfaces remain a major safety concern, highlighting the need for elastomeric materials that combine ice traction with abrasion durability. This dissertation investigates the development, characterization, and prediction of textured polymer composites through experimental tribology, interfacial engineering, and machine learning. First, a novel laboratory-scale high-velocity ice tribotesting method was developed using a modified Bruker UMT Tribolab to evaluate small rubber composite specimens under walking-relevant conditions. Rotational sliding provided more reliable friction measurements than reciprocating motion, establishing a practical approach for high-throughput materials screening. Second, thermoplastic polyurethane (TPU) nanocomposites reinforced with pristine and acid-functionalized graphene nanoplatelets (GNPs) were developed to improve ice traction and abrasion resistance. GNP functionalization enhanced filler dispersion, interfacial adhesion, and mechanical performance. Bioinspired surface texturing and abrasion-induced surface evolution generated functional micro-asperities and channels that supported ice traction after wear. TPU containing 20 phr functionalized GNPs demonstrated the best balance between abrasion resistance and retained ice traction. Finally, machine learning models were developed to predict TPU abrasion resistance from mechanical and viscoelastic properties, with decision tree and gradient boosting regressors demonstrating promising predictive performance. An additional industrial study extended data-driven modeling to automotive polymer composites, including predictive model development and graphical user interface implementation. Overall, this research establishes an integrated experimental and computational approach for developing durable, wear-adaptive elastomeric composites with enhanced ice traction and predictive material design capabilities.
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    The function of the fission yeast LARP1 ortholog Slr1p in the regulation of mRNA translation and decay
    (2026-11-06) Kanaan, Joudi; Mark Bayfield
    Gene expression is the process by which information encoded in DNA is used to produce functional products. Protein-coding genes are transcribed into messenger RNA (mRNA), which is translated into proteins. Translation is highly regulated, with initiation, elongation, and termination influenced by cellular conditions and regulatory proteins. In Schizosaccharomyces pombe, the LARP1 ortholog Slr1p binds mRNAs and regulates translation, although its molecular functions remain incompletely understood. This study investigates the role of Slr1p in translation regulation and translation-associated mRNA decay under stressed and unstressed conditions. Using dual-luciferase assays, and co-immunoprecipitation, we examined the effects of Slr1p on translation initiation, elongation, programmed ribosomal frameshifting, and its interaction with the 5′–3′exonuclease Exo2p. We hypothesized that Slr1p promotes translation while coordinating mRNA decay through Exo2p, thereby linking protein synthesis with mRNA turnover. Understanding Slr1p function may reveal conserved regulatory mechanisms and provide insight into the roles of LARP1 proteins in disease, including cancer.
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    Assessing recovery in storm surge impacted lakes of the outer Mackenzie Delta, NT, Canada
    (2026-11-06) Tuz, Rebecca Evalyn; Joshua Thienpont
    Low-lying ecosystems within Canada’s Arctic regions have experienced an increased frequency and intensity of storm surge events in recent decades, due to the impacts of anthropogenic climate changes. Following a severe storm surge that took place in September 1999, lakes in the northwest Mackenzie Delta (NT, Canada) were fundamentally altered. Lake sediment cores were collected a decade after the event for paleolimnological analysis, revealing that some lakes had undergone complete or partial transition to brackish environments. However, the condition of the lakes had not been assessed in the last 15 years, and it is unknown if the lakes have recovered, remain highly disturbed, or have been impacted by subsequent storm surge events. The purpose of this study was to assess recent ecosystem trajectories in storm surge-impacted lakes of the outer Mackenzie Delta using contemporary water chemistry and paleolimnological analyses of sedimentary diatom assemblages. Findings indicate that recovery trajectories vary substantially among lakes, largely due to the spatially heterogeneous and non-linear nature of recovery from saltwater intrusion in Arctic coastal ecosystems. Differences in recovery trajectories emphasize the importance of local hydrology, landscape position, and lake-specific characteristics in determining ecosystem resilience. As climate change continues to increase the likelihood of coastal flooding and storm surge events across the Arctic, understanding these recovery processes will be critical for predicting future ecological change in northern deltaic environments.
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    COMMODITY BOOMS, FRONTIER DYNAMICS, AND PETTY CAPITALIST FARM ENTERPRISE IN THE SOUTHERN CONE AGRO-EXPORT COMPLEX: ARGENTINA AND PARAGUAY IN COMPARATIVE PERSPECTIVE
    (2026-11-06) Sabbatasso, Esteban; Viviana Patroni
    This dissertation examines the conditions shaping the persistence and transformation of petty commodity production in capital-intensive agriculture characterized by growing agribusiness concentration. Drawing on Marxist agrarian political economy, it develops a comparative historical analysis of the Pampas and central Chaco in Argentina and southeastern Paraguay within the Southern Cone’s soybean agro-export complex. The research combines 77 semi-structured interviews and field observations from 2021–2022 with documentary analysis and census, cadastral, and trade data. Organized around land, labour, and capital, it traces how commodity booms and agricultural frontier expansion have shaped agrarian structures since the colonial period. The findings show that concentration within value chains can coexist with differentiated units of farm production. Where mechanisms exist to secure supplies from dispersed producers, agribusiness firms may benefit from offloading substantial cultivation risks. Historically constituted property relations, differential ground rent, and state mediation shape farm viability, while cooperatives and machinery contracting facilitate access to technology, markets, and economies of scale. These conditions have favoured the persistence of technologically advanced petty commodity production in the Pampas and parts of eastern Paraguay, while pressures toward concentration and displacement are especially pronounced in Argentina’s Chaco. Such persistence nevertheless coexists with continual competitive attrition, pressures for technical reorganization, and, in some cases, differentiation into petty capitalist farm enterprises. The dissertation explains the conditional viability of petty commodity production, distinguishing its continuity as a distinct form from the survival of individual enterprises. It also relates these material conditions to producers’ ideological orientations and associational life, examining their political implications.
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    Social Reproduction, Governmentality and Resilience: Unpaid food work of first-generation immigrant women in the community
    (2026-11-06) Kalyanaraman, Shruti; Tania Das Gupta
    Community work involving first-generation immigrant (FGI) women, though indispensable for many non-profit organizations, needs nuanced discussion in academic and policy conversations. My research centers on FGI women’s volunteer work in food-based non-profits, including food banks and community food organizations. I use the interdisciplinary concepts of social reproduction, governmentality and resilience to understand the intersectional nuances that arise in the lived experiences and situated knowledges of FGI women community volunteers. I center Black, Indigenous, migrant and other marginalized feminist scholarship to contextualize first-generation immigrant food work. I juxtapose this scholarship and my field learnings against my own positionality and geographies of space and place. This includes both my caste privilege, model minority immigrant status and settler privileges and my marginalization as a racialized woman, mother and first-generation immigrant with limited social capital. I present three key learnings from my research:1. Migration stories are intersectional, and reasons to volunteer can be varied and informed by both personal choices and socio-economic structures like family, religion, ethnicity, institutions, local and federal governments; 2. Governmentality plays a key role in influencing FGI women’s community social reproduction and the feminization of non-profit food advocacy organizations; 3. FGI women and other workers in the non-profit food sectors show resilience and resistance in reorganizing and negotiating systemic barriers posed by the precarious environment, including funding issues, spatial constraints, and the transitional nature of care work. In certain aspects of social reproduction, I observed the existence of temporary activities that often get subsumed under broadly defined activities of cooking, cleaning, childcare, eldercare, volunteering, advocacy, etc. I call it transience in social reproduction. This transience was seen in sudden, unexpected requirements of care carried out within social reproduction activities, like picking up a neighbour’s child from school, along with one’s own; the children wanting to play in the school park while you mind them. These requirements of care are fluid, temporary and episodic, but part of social reproduction labour.