Trent University

The oyster mushroom, Pleurotus ostreatus, is one of the most widely cultivated edible basidiomycetes. It has gained increased attention for its economic, environmental, and medicinal properties. While a lot is known about cytokinins (CKs) and their actions at the molecular and cellular levels in plants, much less is known about the function of CKs in other kingdoms. Cytokinins, which have been detected in several fungal species, play a role in pathogenic attack against plants or during plant growth promotion by plant beneficial microbes; however, the role of CKs in fungal physiology, separate from plant associations remains largely unknown. This thesis focuses on the occurrence of fungal-derived CKs in P. ostreatus when grown in vitro as submerged or aerial mycelium. Cytokinin profiling by UHPLC-HRMS/MS revealed that P. ostreatus produces CKs and that the tRNA degradation pathway is the main source of these molecules. CK dynamics within fungal growth supported previous evidence, which suggested that tRNA degradation products have a role in the physiological development of fungi for which CKs act as fungal growth regulators. A second component of the thesis demonstrated that P. ostreatus responds to exogenous applications of aromatic and isoprenoid CKs and their effects were dependent on the dose and CK type. N6-Benzyladenine (BAP), Kinetin (KIN), N6-isopentenyladenine (iP), and trans-zeatin (tZ) bioassays revealed hormone-type responses (hormesis: biphasic response). At low doses, mycelium growth could be stimulated, whereas, at high doses only inhibitory effects were observed. This stimulation/inhibition was observed whether the measured response was an increase/decrease of aerial mycelium colony diameter, biomass accumulation or a change in mycelium morphology as compared to the controls. Results indicated there is potential to alter mycelium growth and development of P. ostreatus; thus, CKs may play the role of a "mycohormone" and may be specifically helpful for medicinal fungi by increasing growth and efficiency to produce many biologically active substances with valuable medical and environmental applications.

Author Keywords: cytokinins, fungal-derived CKs, hormesis, mycelium, mycohormone, Pleurotus ostreatus

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

Peatlands can be found widely across all latitudes and play a significant role in global cycles within the earth's biosphere. The anoxic conditions in peatlands promotes the accumulation of organic matter through decreased rates of decomposition and the storage of certain elements, which have received contaminant loading over the course of human existence, with significant increases occurring during the period of industrialization. We assessed global patterns of metal enrichment in peatlands in 439 cores distributed across 5 continents and 21 countries and measured 35 elements by depth increments and by peatland type. Global patterns in enrichment factors (EF's) were determined for all metals with the majority of metals being found to have a median EF < 2 indicating relatively minor enrichment. Principal component analysis indicated EF's of 6 metals (Cd, Co, Cu, Ni, Pb, and Zn), 2 metalloids (As and Sb) and Se in the upper peat horizon had similar spatial patterns among peatlands and these elements had generally the highest EF's with many cores exceeding EF >10 and some having EF values >100. Significant differences in EF's were found for these 9 "pollution" elements by peatland type and to a greater extent by geographic region, with higher EF values typically occurring in Europe and North America. Enrichment factors for most elements exhibited weak but significant positive correlations with modelled [1850 – present] S deposition. Estimated pools for the "pollution metals" within the 0 - 40 cm depth varied considerably, with median global pools in peat ranging from 12.9 mg m-2 (Sb) to 439 mg m-2 (Zn) for these 9 metals. Climate changes presents a significant risk to global peatland geochemistry due to expected changes in hydrologic regimes, resulting in potentially increased metal mobility though drought-induced peatland acidification, with historic areas previously impacted by industrial activities presenting the greatest risk of metal release to downstream receiving environments. Using a case study, we examined the impact of simulated 30-day drought on pore water chemistry at six sites in a peatland complex in Elliot Lake Ontario that were historically impacted by uranium (U) mining activities. All sites responded similarly to simulated drought with pore water pH significantly declining. The decline in pore water pH was likely due to increasing sulphate (SO42-) concentrations, which accompanied large increases in Al, Ni, Cu, Pb, Zn, and U. Dissolved organic carbon (DOC) increased, which may further enhance Al, Cu, and U mobility as these metals are strongly complexed by organic acids. Metal partitioning (Kd) values could be significantly predicted by pH and DOC although the strength of the relationship varied considerably among sites. Multiple linear regression and the inclusion of SO4-2 improved predictions, indicating that declines in pH as a result of SO4-2 and H+ production primarily governs metals and U partitioning in peatland soils. The results from both studies show that metal enrichment in global peatlands is highly variable, with northern peatlands in industrialized areas presenting the greatest risk of metal release to downstream surface waters based on expected hydrologic impacts from climate change due to historical and on-going metal and S deposition.

Author Keywords: Acidification, Climate Change, Drought, Enrichment Factors, Global, Peatlands

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

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

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

Fisheries assessment and management approaches have historically focused on individual species over relatively short timeframes. These approaches are being improved upon by considering the potential effects of both broader ecological and evolutionary processes. However, only recently has the question been raised of how ecological and evolutionary processes might interact to further influence fisheries yield and sustainability. My dissertation addresses this gap in our knowledge by investigating the role of eco-evolutionary dynamics in a commercially important lake whitefish fishery in the Laurentian Great Lakes, a system that has undergone substantial ecosystem change. First, I link the timing of large-scale ecological change associated with a species invasion with shifts in key density-dependent relationships that likely reflect declines in the population carrying capacity using a model selection approach. Then, using an individual-based model developed for lake whitefish in the southern main basin of Lake Huron, I demonstrate how ecosystem changes that lower growth and recruitment potential are predicted to reduce population productivity and sustainable harvest rates through demographic and plastic mechanisms. By further incorporating an evolutionary component within an eco-genetic model, I show that ecological conditions also affect evolutionary responses in maturation to harvest by altering selective pressures. Finally, using the same eco-genetic model, I provide a much-needed validation of the robustness of the probabilistic maturation reaction norm (PMRN) approach, an approach that is widely used to assess maturation and infer its evolution, to ecological and evolutionary processes experienced by exploited stocks in the wild. These findings together highlight the important role that ecological conditions play, not only in determining fishery yield and sustainability, but also in shaping evolutionary responses to harvest. Future studies evaluating the relative effects of ecological and evolutionary change and how these processes interact in harvested populations, especially with respect to freshwater versus marine ecosystems, could be especially valuable.

Author Keywords: Coregonus clupeaformis, density-dependent growth, fisheries-induced evolution, individual-based eco-genetic model, Lake Huron, stock-recruitment

The study sought to uncover the motivations influencing collectors when they buy recorded music. These motivations were analyzed through the lenses of environmental, economic, and cultural sustainability. Trent Radio Programmers were interviewed because of their frequent use of recorded music, sizable collections, and active participation in the local music scene. The study identified disconnects between artist, industry, and consumer motivations that hinder the achievement of a sustainable system. Environmental sustainability was not considered, while the artists' economic and cultural sustainability were. This finding translates to the idea that in the music industry, to strengthen cultural sustainability, economics must be supported, which requires environmental impact. This research has the potential to catalyze critical conversations about digital media, artist welfare, and the state of the music industry.

Author Keywords: College Radio, Cultural Sustainability, Economic Sustainability, Environmental Sustainability, Music Collecting

A comparison of two high performance computing clusters running on AWS and Sharcnet was done to determine which scenarios yield the best performance. Algorithm complexity ranged from O (n) to O (n3). Data sizes ranged from 195 KB to 2 GB. The Sharcnet hardware consisted of Intel E5-2683 and Intel E7-4850 processors with memory sizes ranging from 256 GB to 3072 GB. On AWS, C4.8xlarge instances were used, which run on Intel Xeon E5-2666 processors with 60 GB per instance. AWS was able to launch jobs immediately regardless of job size. The only limiting factors on AWS were algorithm complexity and memory usage, suggesting a memory bottleneck. Sharcnet had the best performance but could be hampered by the job scheduler. In conclusion, Sharcnet is best used when the algorithm is complex and has high memory usage. AWS is best used when immediate processing is required.

Author Keywords: AWS, cloud, HPC, parallelism, Sharcnet

Cis-isomers of the cytokinin plant hormone family are thought to have low activity or impact on plant growth and development. Mutants with independent silencing of the pathway leading to cis-CK (cis-cytokinin) were investigated at the phenotype and metabolite levels. Phenotypic deviations were noted in trichome development, fresh weight, rosette diameter, number of non-rosette leaves, shoot height, delayed flowering, flower number, and carotenoids. Exploratory metabolomic analysis detected a number of metabolite features that have been associated with CK, auxin, and ABA (abscisic acid) activity. Evidence from both phenotype and metabolomic analysis support the hypothesis that cis-CK production is biologically important for plant growth and development.

Author Keywords: arabidopsis, cytokinin, IPT, metabolmics