Graduate Theses & Dissertations


role of Cln5 in autophagy, using a Dictyostelium discoideum model of Batten disease
This thesis investigated the role of the neuronal ceroid lipofuscinosis protein, Cln5, during autophagy. This was accomplished by performing well-established assays in a Dictyostelium cln5 knockout model (cln5-). In this study, cln5- cells displayed a reduced maximum cell density during growth and impaired cell proliferation in autophagy-stimulating media. cln5- cells had an increased number of autophagic puncta (autophagosomes and lysosomes), suggesting that autophagy is induced when cln5 is absent. cln5- cells displayed increased amounts of ubiquitin-positive proteins but had no change in proteasome protein abundance. During the development of cln5- cells, fruiting bodies developed precociously and cln5- slug size was reduced. Lastly, when cln5- cells were developed on water agar containing ammonium chloride (NH4Cl), a lysosomotropic agent, the formation of multicellular structures was impaired, and the small slug phenotype was exaggerated. In summary, these results indicate that Cln5 plays a role in autophagy in Dictyostelium. The cellular processes that regulate autophagy in Dictyostelium are similar to those that regulate the process in mammalian cells. Thus, this research provides insight into the undefined pathological mechanism of CLN5 disease and could identify cellular pathways for targeted therapeutics. Author Keywords: Autophagy, Batten disease, Cln5, Dictyostelium discoideum, NCL
role of corticosterone in breeding effort and reproductive success in tree swallows
Glucocorticoids (e.g., corticosterone (CORT)) are hypothesized to mediate decisions regarding reproductive investment during breeding, but the directionality of the relationship is not clear. The CORT-fitness hypothesis posits that high levels of CORT arise from challenging environmental conditions in which an individual will conserve resources for future reproduction or self-maintenance, and thus result in lower reproductive success (a negative relationship). In contrast, the CORT-adaptation hypothesis suggests that, during energetically demanding periods, CORT will mediate physiological or behavioural changes that result in increased reproductive investment and success (a positive relationship). Inconsistencies arise due to the various species and life-history stages studied, and the complex interactions between fitness and glucocorticoids. Using an experimental approach, I investigated the relationship between CORT and reproductive success by manipulating baseline CORT levels in female tree swallows Tachycineta bicolor prior to laying using silastic implants. Implants failed to raise CORT levels of females during either incubation or the nestling stage, and maternal treatment had no effect on indices of fitness at either stage. Using a correlative approach, partial support for the CORT-adaptation hypothesis was found: There was a positive relationship between CORT and hatching success. This only occurred when CORT was measured during incubation, when baseline CORT levels may stimulate increased reproductive effort and success. In contrast, during the nestling stage baseline CORT levels were not related to reproductive investment or success. Maternal CORT levels during incubation also did not influence nestling phenotype, although nestling stress CORT levels were higher in individuals that survived to fledging. In conclusion, CORT mediates reproductive effort and success during some breeding stages, but it is still unclear why this is the case and whether this same pattern will prevail in other contexts. Author Keywords: corticosterone, HPA axis, maternal effects, reproductive success, tree swallow
significance of topographically-focused groundwater recharge during winter and spring on the Oak Ridges Moraine, southern Ontario
The Oak Ridges Moraine (ORM) is a key hydrogeologic feature in southern Ontario. Previous work has emphasized the importance of depression-focused recharge (DFR) for the timing and location of groundwater recharge to the ORM’s aquifers. However, the significance of DFR has not been empirically demonstrated and the relative control of land cover, topography, and surficial geology on DFR is unclear. The potential for DFR was examined for topographic depressions under forested and open, agricultural land covers with similar soils and surficial geology. Recharge (R) was estimated at the crest and base of each depression during the 2012-13 and 2013-14 winter-spring periods (~December – May) using both a 1-dimensional water balance approach and a surface-applied Br- tracer. At each depression, air temperatures, precipitation, snow depth and water equivalent, soil water contents, soil freezing, and depression surface-water levels were monitored and soil properties (texture, bulk density, porosity, and hydraulic conductivity) were measured. Both forested and agricultural land covers experienced soil freezing; however, concrete frost did not develop in the more porous and conductive forest soils. Concrete frost in agricultural depressions resulted in overland flow, episodic ponding and drainage of rain-on-snow and snowmelt inputs. Recharge was an order-of-magnitude greater at the base of open depressions. Observations of ponding (as evidence of DFR) were made at an additional 14 depressions with varying land cover, geometry, and soil type during the 2014 snowmelt period and measurements of pond depth, pond volume, land cover (i.e., percentage of agricultural vs. forested cover), depression geometry (i.e., contributing area, average slope, relief ratio) and soil texture were made. Ponding was restricted to depressions under mostly agricultural cover and a positive, non-linear relationship between pond volume and average slope was shown for sites with similar land cover and soil texture, but neither pond depth nor volume were related to any other depression characteristics. Results suggest that DFR is a significant hydrologic process during winter and spring under agricultural land cover on the ORM. Topographic depressions under agricultural land cover on the ORM crest may serve as critical recharge “hot spots” during winter and spring, and the ability of the unsaturated zone beneath these depressions to modify the chemistry of recharging water deserves further attention. Author Keywords: Concrete frost, Depression-focused groundwater recharge, Oak Ridges Moraine, Ponding, Topographic depressions, Water balance
silicon sol-gel approach to the development of forensic blood substitutes
The research and development of synthetic blood substitutes is a reported need within the forensic community. This work contributes to the growing body of knowledge in bloodstain pattern analysis by offering a materials science approach to designing, producing and testing synthetic forensic blood substitutes. A key deliverable from this research is the creation of a robust silicon-based material using the solution-gelation technique that has been validated for controlled passive drip and spatter simulation. The work investigates the physical properties (viscosity, surface tension and density) of forensic blood substitute formulations and describes the similarity in the spreading dynamics of the optimized material to whole human blood. It then explores how blood and other fluids behave in impact simulation using high-speed video analysis and supports the use of the optimized material for spatter simulation. Finally, the work highlights the practical value of the material as an educational tool for both basic and advanced bloodstain experimentation and training. Author Keywords: bloodstain pattern analysis, forensic blood substitutes, high-speed video analysis, silicon solution-gelation chemistry, thin-film deposition, training and education
sustainability of Community-based Water supply Organizations (CWOs)
The world has met the target of halving the number of people without access to improved-drinking water . However, the focus in rural areas (where 83% of the people without access to improved-drinking water live) has been on the construction of infrastructure, rather than on the strengthening of existing local institutions to create a long-term sustainable solution. This research aims to understand what are the necessary characteristics that CWOs, the main rural water supplier institutions around the world, must have to offer safe water continuously and in the long term. The results indicate that to offer such conditions, internal and external characteristic need to coexist. Those characteristics will emerge from case studies analysis in rural and peri-urban areas in Colombia, through interviews, surveys, document reviews, observation exercises, and a comparison with the literature. Internal characteristics include proper infrastructure conditions, user satisfaction, best management practices, social capital, be a development catalyzer, and environmental awareness. External characteristics include easy access to subsidies, efficient communication channels with authorities, continuous training, and environmental legislation/education. This study concludes that enforcing these characteristics will strengthen the existing institutions and can provide a sustainable solution for rural water supply issues. Author Keywords: community-based water supply organizations, costs, management, financial sustainability, rural Colombia, state subsidies, water tariffs
the sex killer drives a panel pin into his ear-hole
I have two goals. One, to offer new insights into Vienna Actionism (VA) and their notorious performances, through Gilles Deleuze and Félix Guattari’s notion of the body without organs (BwO); and two, not simply to provide descriptions of the Vienna Actionists’ performances, but also to write what I am calling a thesis without organs. Documents from the Vienna Actionists, specifically Muehl’s Leda and the Swan (1964), Brus’ Vienna Walk (1965) and Nitsch’s O.M. Theatre (1960-present), become documents without organs; they are documents that do not simply document original performances, but re-perform original performances while acting as performances themselves. Challenging the notion of live performance as fundamentally separate from its documentation (as performance theorist Peggy Phelan argues) through what Philip Auslander calls the document’s performativity and what Christopher Bedford calls a viral ontology of performance, my thesis becomes a performance in and of itself. A thesis without organs. Keywords: performance, performativity, viral ontology of performance, body without organs, rhizome, dirt, metaphor, metonymy, Vienna Actionism, Gilles Deleuze, Félix Guattari, Peggy Phelan, Philip Auslander, Christopher Bedford, Mary Douglas. Author Keywords: Body without Organs, Performance, Performativity, Vienna Actionism
wind tunnel and field evaluation of the efficacy of various dust suppressants
A series of experiments was designed to assess the relative efficacy of various dust suppressants to suppress PM10 emissions from nepheline syenite tailings. The experiments were conducted in the Trent University Environmental Wind Tunnel, Peterborough, Ontario, and on the tailings ponds at the Unimin Ltd Nephton mine near Havelock, Ontario. Treated surfaces were subjected to particle-free airflow, abrasion with blown sand particles, particle-free airflow after physical disturbance, and were measured independently using a pin penetrometer. In the particle-free wind tunnel tests, three of the surfaces performed well, and PM10 emissions scaled inversely with crust strength. Light bombardment of each surface by saltating sand grains resulted in PM10 emission rates two orders of magnitude higher. All treated surfaces emitted significantly more PM10 after physical disturbance in both the laboratory and field research. The results suggest that the site conditions, inclusive of the potential for dust advection and resuspension, must be taken into account when considering the use of a commercial dust suppressant. Author Keywords: dust suppression, field testing, mine tailings, wind tunnel experiment
wind tunnel based investigation of three-dimensional grain scale saltation and boundary-layer stress partitioning using Particle Tracking Velocimetry
Aeolian transport of sand particles is an important geomorphic process that occurs over a significant portion of the earth’s land surface. Wind tunnel simulations have been used for more than 75 years to advance the understanding of this process; however, there are still several principles that lack validation from direct sampling of the sand particles in flight. Neither the three-dimensional dispersion of, nor the momentum carried by particles in flight have been properly measured. This has resulted in the inability to validate numerical particle dispersion models and the key boundary-layer momentum partitioning model that serves as the framework for understanding the air-sand feedback loop. The primary impediment to these measurements being made is a lack of tools suited for the task. To this end, this PhD aims to improve existing particle tracking technology, thus enabling the collection of particle measurements during wind tunnel experiments that would address the aforementioned knowledge gaps. Through the design and implementation of the Expected Particle Area Searching method, a fully automated particle tracking velocimetry system was developed with the capability to measure within ½ grain diameter of the bed surface under steady state transport conditions. This tool was used to collect the first 3-D data set of particle trajectories, from which it was determined that a mere 1/8th of sand transport is stream aligned and 95% is contained within ± 45o of the mean wind direction. Particles travelling at increasing spanwise angles relative to the stream aligned flow were found to exhibit different impact and ejection velocities and angles. The decrease in the number of particles with increasing height in the saltation cloud, very close to the bed is observed to transition from a power to a linear relation, in contrast to previous literature that observed an exponential decay with coarser vertical resolution. The first direct measurements of particle-borne stress were captured over a range of wind velocities and were compared with earlier fluid stress measurements taken using Laser Doppler Anemometry. In support of established saltation theory, impacting particle momentum is found to contribute strongly to particle entrainment under equilibrium conditions. In opposition to established theory, however, particle-borne stress was found to reach a maximum above the surface and does not match the change in air-borne stress with increasing distance from the surface. Near surface splashed particles, measured herein for the first time, appear to play a greater role in stress partitioning than previously thought. This study suggests that research is needed to investigate the role of bed load transport on stress partitioning, to differentiate between airborne trajectory types, and to develop particle tracking tools for field conditions. Author Keywords: Aeolian Transport, Eolian Transport, Particle Tracking Velocimetry, Saltation, Stress Partitioning, Wind Tunnel Simulation
This thesis is about the ways in which Indigenous dance serves as a social determinant of Indigenous health and well-being. Utilizing both contemporary and traditional versions of the Medicine Wheel for the framework, analysis and organization of the thesis allows for a holistic perspective which includes the spiritual, physical, emotional and mental aspects. The importance of Indigenous dance for Indigenous health and well-being is confirmed through: existing literature; interviews with Indigenous choreographers, dancers, theatre artists, and performers; Indigenous exponents of the forms; and Indigenous Elders. In order to contextualize current practices of Indigenous dance, the history of Indigenous dance in relation to colonization is presented. The research and experiences of co-researchers show the need for Indigenous dance and culture to be supported as a social determinant of health and well-being. Author Keywords:
“A City is Not a Place of Origins”
This thesis explores the work of Black queer authors who write and reproduce cities in their texts. James Baldwin and Dionne Brand create knowable and readable spaces of the cities in which they write. By studying the work of these two authors, this thesis seeks to understand how Black queer people navigate city spaces, and how Black queer authors create a literary imaginary about the cities in which their novels are set. Thus, the cities of New York and Toronto become knowable sites through the novels of Dionne Brand and James Baldwin. Using Black queer theory, Black diaspora theory, and Black literary theory, this thesis engages with the novels, essays, and interviews of James Baldwin and Dionne Brand to determine that urban spaces are both liberatory and traumatic for Black queer people. Author Keywords: Baldwin, Black Queer Studies, Black Women, Brand, Diaspora Studies, Lesbian
“At least I can feel like I’ve done my job as a mom”
This study examines the household foodwork of low-income mothers in Peterborough, Ontario and considers how community food initiatives (CFIs) such as community gardens and good food box programs can support these women in their efforts to feed their families adequately. I draw on multiple data sources: interviews with representatives from Peterborough CFIs; interviews with and illustrations by 21 local low-income mothers; debrief sessions following participants’ tours of CFIs; and my ongoing involvement with two local food networks. The mothers’ extensive foodwork considerations, strategies, and struggles reflect an engagement with three main ideals that are placed further out of reach through poverty and food insecurity. Women experienced pressure through these ideals: the “good mother,” to take primary responsibility for their children’s well-being through food; the “good consumer,” to participate in society as individual consumers; and the “good food program participant,” to avoid indications of over-reliance on food programs. Each ideal reflects the neoliberal exaltation of self-sufficiency and its flipside, the vilification of dependence. The research results highlight the need for CFIs to focus on the broader, systemic discursive and material challenges that can hamper the foodwork of all low-income mothers, in addition to addressing the immediate needs of their own participants. Towards this goal, Peterborough CFIs employ principles of universality, social inclusion, democratic processes, and broadening of social imaginaries. In their efforts, CFIs must navigate between cultivating collectivity and interdependence on the one hand, and engaging with this familiar, individualizing neoliberal ethos on the other hand. This study provides insights about the subjectivities of low-income mothers that may be useful for CFI programming as well as more analytic examinations of the role and impact of CFIs. It also reveals the common feminization, devaluation, and under resourcing of the food-related work of both mothers and CFIs. In doing so, the study points to the urgent need for broad dialogue and political action regarding poverty, dependence, caring labour, and the roles of citizens and the state in ensuring that households can adequately feed themselves. Author Keywords: Community Food Initiatives, Community Food Programs, Domestic Labour, Food Insecurity, Gendering of Caring Labour, Household Food Work
“Has anybody got my back?”
Drawing on pedagogies of care, queer pedagogy and Foucault’s concept of biopower, this critical narrative study of six women teachers at an Ontario school uses interview data to explore how teaching affects women’s bodies. Findings include the dominance of men in schools; the high rate of violence against teachers committed by students; participants’ unwillingness to show bodily discomfort to students; and the profound effect of motherhood on teaching practice. I call on educators and school administrators to embed care of students’ and teachers’ bodies into the practices of schooling. I also propose that instead of erasing teacher corporeality from classrooms, we allow students to care for teachers’ bodies as part of a healthy, reciprocal caring relationship, developing students’ and sustaining teachers’ capacity to care. Given the underrepresentation of women’s voices speaking about violence against teachers, this thesis is also a repository for women’s narrated stories of assault in Ontario schools. Author Keywords: biopedagogies, body, care, narrative inquiry, pedagogy, teacher


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