Graduate Theses & Dissertations

Pages

Modelling Monthly Water Balance
Water balance models calculate water storage and movement within drainage basins, a primary concern for many hydrologists. A Thornthwaite water balance model (H2OBAAS) has shown poor accuracy in predicting low flows in the Petawawa River basin in Ontario, so lake storage and winter snow processes were investigated to improve the accuracy of the model. Lake storage coefficients, represented by the slopes of lake stage vs. lake runoff relationships, were estimated for 19 lakes in the Petawawa River basin and compared on a seasonal and inter-lake basis to determine the factors controlling lake runoff behaviour. Storage coefficients varied between seasons, with spring having the highest coefficients, summer and fall having equal magnitude, and winter having the lowest coefficients. Storage coefficients showed positive correlation with lake watershed area, and negative correlation with lake surface area during summer, fall, and winter. Lake storage was integrated into the H2OBAAS and improved model accuracy, especially in late summer, with large increases in LogNSE, a statistical measure sensitive to low flows. However, varying storage coefficients with respect to seasonal lake storage, watershed area, and surface area did not improve runoff predictions in the model. Modified precipitation partitioning and snowmelt methods using monthly minimum and maximum temperatures were incorporated into the H2OBAAS and compared to the original methods, which used only average temperatures. Methods using temperature extremes greatly improved simulations of winter runoff and snow water equivalent, with the precipitation partitioning threshold being the most important model parameter. This study provides methods for improving low flow accuracy in a monthly water balance model through the incorporation of simple snow processes and lake storages. Author Keywords: Lake Storage, Model Calibration, Monthly Water Balance, Petawawa River, Precipitation Partitioning, Snow Melt
Comparison of Dehydration Techniques for Acute Weight Management in Rowing
Mild sauna dehydration and fluid abstinence were investigated as weight loss strategies for lightweight rowers. Rowers (N=12) performed a power test, an incremental VO2max test, and a visuomotor battery: once euhydrated, once following sauna dehydration (SAU), and once following fluid abstinence and then sauna dehydration (FA). The percent body mass change (%BMC) achieved, %BMC attributable to sauna dehydration, and %BMC attributable to fluid abstinence were used within linear mixed effects models to predict hydration and performance variables. Sauna and overnight dehydration exerted indistinguishable effects on plasma osmolality, urine osmolality and thirst (p > .05). Fluid abstinence but not sauna dehydration was related to lower power production on the power test (b = 12.14W / 1%BMC, FA = 673.46 ± 79.50, SAU = 683.33 ± 72.08, p = .029), a lower total wattage produced on the incremental VO2max test (b = 4261.51W / 1%BMC, FA = 71029.58 ± 16256.56, SAU = 74001.50 ± 14936.56, p = .006), lower wattages at 2 mmol/L (b = 27.84W / 1%BMC, FA = 180.74 ± 40.27, SAU = 190.82 ± 50.79, p < .001) and 4 mmol/L (b = 20.45W / 1%BMC, FA = 221.90 ± 52.62, SAU = 238.89 ± 40.78, p = .002) blood lactate, and slower movement time on a visuomotor task (b = -38.06ms / 1%BMC, p = .004). Mild fluid abstinence but not sauna dehydration reduces rowing performance when two-hour rehydration is allowed. Author Keywords: crew, fluid, hydration, lightweight, sauna, weight
“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
Shorebird Habitat Use and Foraging Ecology on Bulls Island, South Carolina During the Non-Breeding Season
Recent declines in North American shorebird populations could be linked to habitat loss on the non-breeding grounds. Sea-level rise and increased frequency of coastal storms are causing significant erosion of barrier islands, thereby threatening shorebirds who rely on shoreline habitats for foraging. I conducted shorebird surveys on Bulls Island, South Carolina in the winters of 2018 and 2019 and examined habitat selection and foraging behaviour in Dunlin (Calidris alpina), Sanderling (Calidris alba), Semipalmated Plovers (Charadrius semipalmatus), and Piping Plovers (Charadrius melodus). Area, tidal stage, and invertebrate prey availability were important determinants of shorebird abundance, behaviour, and distribution. My study highlights the importance of Bulls Island’s habitat heterogeneity to supporting a diverse community of non-breeding shorebirds. Considering both the high rate of erosion and the increased frequency of disturbance along the shoreline of the island, intertidal habitats should be monitored to predict negative effects of changes in habitat composition and area on non-breeding shorebirds. Author Keywords: foraging behaviour, habitat loss, habitat selection, invertebrate prey, non-breeding, shorebirds
Discriminating grey wolf (Canis lupus) predation events in a multi-prey system in central Saskatchewan
I investigated if spatio-temporal behaviour of grey wolves (Canis lupus) determined via GPS collar locations could be used to discriminate predation events generally, and among prey species, in Prince Albert National Park during winter, 2013-2017. I used characteristics of spatio-temporal GPS clusters to develop a predictive mixed-effect logistic regression model of which spatial clusters of locations were wolf kill sites. The model suffered a 60 % omission error when tested with reserved data due to the prevalence of deer kills with correspondingly low handling time. Next, I found a multivariate difference in the percentage of habitat classes used by wolves in the 2 hours preceding predation events of different prey species, suggesting that wolf habitat use reflects prey selection at a fine-scale. My results highlight the difficulty and future potential for remoting discriminating wolf predation events via GPS collar locations in multi-prey ecosystems. Author Keywords: Canis lupus, GPS clusters, GPS collars, grey wolf, habitat use, predation
multi-faceted approach to evaluating the detection probability of an elusive snake (Sistrurus catenatus)
Many rare and elusive species have low detection probabilities, thereby imposing unique challenges to monitoring and conservation. Here, we assess the detection probability of the Eastern Massasauga (Sistrurus catenatus) in contrast to a more common and conspicuous species, the Eastern Gartersnake (Thamnophis sirtalis). We found that patterns of detection probability differed between species, wherein S. catenatus was detected less often and under a more specific set of sampling conditions. Correspondingly, detection trials with S. catenatus found a high non-detection rate, while detection trials with artificial models suggest that regional differences in detection probability are driven by variation in population density and habitat use. Our results suggest that current monitoring efforts are not sufficient, and that S. catenatus is frequently undetected. Accordingly, we highlight the importance of species-specific monitoring protocols when monitoring rare and elusive species, and recommend a multi-faceted approach that estimates detection probability and identifies species-specific challenges to monitoring. Author Keywords: detection probability, elusive species, monitoring programs, non-detection, S. catenatus, snakes
History of Canada's UFO Investigation, 1950-1995
From 1950-1995, the Canadian government investigated the phenomenon of unidentified flying objects (UFOs), amassing over 15,000 pages of documentation about, among other matters, nearly 4,500 unique sightings. This investigation was largely passive and disconnected, spread across a number of federal departments and agencies that infrequently communicated about the subject. Two official investigations, Project Magnet and Project Second Storey, were initiated in the early 1950s to study the topic. The government concluded that the UFO phenomenon did not “lend itself to a scientific method of investigation,” and terminated the projects. After this point, the investigation entered a state of purgatory, with no central communication, and every government department eager to pass the responsibility onto someone else. As such, Canadian citizens writing to the government for straight answers to the UFO enigma were often on the receiving end of what they called “doublespeak.” Citizens were seeing things in the sky and wanted the government to simply tell them what they were. The government was unable and unwilling to do this, and over time frustration grew on both sides. What began for the government, in its own words, as an irritating intrusion into more important matters, became the catalyst for a dynamic of mutually-reinforced mistrust between state and citizen during the postwar period. This dissertation offers a chronological history of the efforts that the Canadian government and citizens made to investigate UFOs, and when and why these efforts came into conflict. The main argument is that the Canadian state attempted to use UFOs as a site to assert its modernity during a time of uncertainty and anxiety over its legitimacy, by drawing on the cultural authority of the scientific community. The project was one of ridding the public of ignorance and creating instead a more rational citizen. This attempt ran up against beliefs and attitudes that some citizens shared, that tapped into a spirit of anti-authoritarianism present during the 1960s and even earlier. These citizens considered themselves to be iconoclasts, unmoved by claims of expertise, and accused the government of conspiracy theory. These approaches fed into one another, contributing to further misunderstanding and conflict. The history of Canada’s UFO investigation is thus more broadly a history of changing attitudes toward authority and expertise in the postwar era. Author Keywords: Canada, citizenship, history of science, scientific object, state, UFO
Pervert’s New Statesman
Justice Weekly was a tabloid published in Toronto from 1946 to 1972. The popular narrative is that it was an unremarkable, obscure, and pornographic paper which was co-opted by gay and homophile voices in the 1950s. But why did a magazine best remembered, as Mordecai Richler put it, as “the pervert’s new statesman” publish this material? This thesis argues that Justice Weekly really was primarily about Justice, rather than titillation. The paper explored justice through topics such as juvenile delinquency and spanking, which allowed sexualized material to appear, as well as conversations surrounding gay men, race, criminality, and punishment. While the paper outed gay men and often argued for harsher prison conditions, it also published material from Canada’s earliest gay activists and prisoner presses. Justice Weekly’s focus on equitable justice allowed both sex and advocacy to emerge from its content. Author Keywords: Delinquency, Homosexuality, Jim Egan, Pornography, Pulp, Tabloid
That '70s Strike Support
This thesis examines three Ontario strikes during the 1970s: the Dare Foods, Ltd. strike in Kitchener, Ontario, 1972-1973; the Puretex Knitting Company strike in Toronto, 1978-1979; and the Inco strike in Sudbury, 1978-1979. These strikes highlight gender issues in the Canadian food production, textile, and mining industries in the 1970s, industries that were all markedly different in size and purpose, yet equally oppressive towards working women for different reasons, largely based on the regional character of each city the strikes took place in. In Kitchener, the women’s movement worked closely with the Dare union local and the left to mobilize against the company and grappled with the difficulties of framing women’s inequality within the labour movement. At Puretex, immigrant women workers were subject to electronic surveillance as a form of worker control, and a left-wing nationalist union needed to look outside of the Canadian Labour Congress (CLC) for allies in strike action. At Inco, an autonomous women’s group formed separate from the United Steelworkers of America (USWA) but struggled to overcome a negative perception of women’s labour activism in Sudbury. Ultimately, these strikes garnered a wide variety of support from working women and feminist groups, who often built or had pre-existing relationships with Canadian and American trade unions as well as the left-wing milieu of the 1970s. This thesis uses these strikes as case studies to argue that despite the complicated and at times uneven relationship between feminism, labour, and the left in the 1970s, feminist and left-wing strike support was crucial in sustaining rank-and-file militancy throughout the decade and stimulating activist careers for women in the feminist movement, in unions, and on the left. Author Keywords: 1970s, feminism, labour, left-wing, militancy, working-class
Effects of Local, Landscape, and Temporal Variables on Bobolink Nest Survival in Southern Ontario
Populations of grassland birds, including the Bobolink (Dolichonyx oryzivorus), are experiencing steep declines due to losses of breeding habitat, land use changes, and agricultural practices. Understanding the variables affecting reproductive success can aid conservation of grassland species. I investigated 1) whether artificial nest experiments accurately estimate the impacts of cattle on the daily survival rate of Bobolink nests and 2) which local, landscape, and temporal variables affect daily survival rate of Bobolink nests in Southern Ontario. I replicated an artificial nest experiment performed in 2012 and 2015 to compare the daily survival rate of artificial and natural nests at multiple stocking rates (number of cattle × days × ha-1). I also monitored Bobolink nests and modeled daily survival rate using local variables (e.g., stocking rate, field use, patch area), landscape variables (e.g., percent forest within 2, 5, and 10 km), and temporal variables (e.g., year, date of season). Results indicate that artificial nest experiments using clay shooting targets overestimated the impacts of stocking rate on the daily survival rate of Bobolink nests. With natural nests, region (confounded by year and field use), stocking rate, and date of season were the strongest predictors of daily survival rate; with stocking rate and date of season both having a negative effect. Management should focus on conserving pastures with low stocking rates (< 40 cattle × days × ha-1), late-cut hayfields, fallow fields, and other grasslands to protect breeding grounds for the Bobolink and other declining grassland bird species. Author Keywords: Bobolink, Daily survival rate, landscape variables, local variables, Nest survival, temporal variables
Impaired contextual fear discrimination learning after long-term amygdala kindling
Cognitive impairments, such as memory loss, are a frequent and devastating co-morbidity associated with epilepsy. The neurobiological mechanisms through which recurrent seizures induce cognitive impairments are not well understood. New neurons born after seizures develop abnormal morphological and functional characteristics that promote network hyperexcitability and hippocampal dysfunction. Previously, we found that kindling dramatically increases the rate of neurogenesis at early stages of seizure development, followed by a long-term suppression at later stages. These changes in the rate of cell proliferation coincides with aberrant modifications in the migration, excitability, and functional integration of these new neurons. It has been suggested that the long-term consequences of seizure-induced neurogenesis contributes to the development of cognitive impairment seen in chronic epilepsy. However, direct experimental evidence has been limited. The present series of experiments sough to determine if blocking aberrant seizure-induced neurogenesis can reduce cognitive deficits associated with chronic epilepsy. Our findings suggest that chronic seizures impair the ability of rats to differentiate between similar contexts. In addition, blocking aberrant seizure-induced neurogenesis through treatment with the cytotoxic agent temozolomide was capable of preventing some of the deficits in context discrimination learning when neurogenesis levels were reduced to non-epileptic control levels. This research provides further support of targeting aberrant neurogenesis as a novel treatment to restore cognitive functioning in individuals living with epilepsy. Author Keywords: Amygdala kindling, Dentate gyrus, Hippocampus, Neurogenesis, Pattern separation, Seizures
Is semantics activated automatically? Evidence from the PRP paradigm
Three experiments examined whether semantics is activated automatically by testing whether Arabic digits (e.g., 4), number words (e.g., four), and non-number words (e.g., rat) activate semantics in the absence of central attention within the Psychological Refractory Period (PRP) paradigm. In all three experiments, subjects performed colour discriminations as Task 1. In Task 2, subjects performed magnitude comparisons on digits (Experiment 1) and number words (Experiment 2) and size comparisons on animal words (Experiment 3). Task overlap was controlled by varying stimulus onset asynchrony (SOA). A distance effect arose in Task 2 and yielded underadditive effects with decreasing SOA for both digits and number words, consistent with these notations activating semantics in the absence of central attention, or automatically. A distance effect also arose for animal words, but it was additive with SOA, inconsistent with non-number words activating semantics automatically. Author Keywords: Automaticity, Central attention, Dual-task, Numerical cognition, Semantics, Word recognition

Pages

Search Our Digital Collections

Query

Enabled Filters

  • (-) ≠ Farell
  • (-) ≠ Bell
  • (-) ≠ Educational Studies

Filter Results

Date

1979 - 2029
(decades)
Specify date range: Show
Format: 2019/12/12

Author Last Name

Show more

Last Name (Other)

Show more