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Graduate Theses & Dissertations
Pages
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- Predictive Digital Mapping of Soils in Kitimat, British Columbia
- Soil is an essential natural resource that supports provisioning services such as agriculture, silviculture, and mining. However, there is limited knowledge on forest soil properties across Canada. Digital soil mapping may be used to fill these data gaps, as it can predict soil properties in areas with limited observations. The focus of this study was to develop predictive maps of select soil physicochemical properties for the Kitimat Valley, British Columbia, and apply these maps to assess the potential impacts of sulphur dioxide emissions from an aluminum smelter, on soil properties in the Valley. Exchangeable [Ex.] magnesium, organic matter, pH, coarse fragment, Ex. potassium, bulk density, Ex. calcium, Ex. acidity, and Ex. sodium were all mapped with acceptable confidence. Time to depletion of base cation pools showed that ~240 km2 of the study area had a depletion time of 50 years or less. However, sources of base cations such as atmospheric deposition and mineral weathering were not considered. Author Keywords: acidification, buffering capacity, Digital soil mapping, predictive mapping, regression kriging, soil properties
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- Utilizing Class-Specific Thresholds Discovered by Outlier Detection
- We investigated if the performance of selected supervised machine-learning techniques could be improved by combining univariate outlier-detection techniques and machine-learning methods. We developed a framework to discover class-specific thresholds in class probability estimates using univariate outlier detection and proposed two novel techniques to utilize these class-specific thresholds. These proposed techniques were applied to various data sets and the results were evaluated. Our experimental results suggest that some of our techniques may improve recall in the base learner. Additional results suggest that one technique may produce higher accuracy and precision than AdaBoost.M1, while another may produce higher recall. Finally, our results suggest that we can achieve higher accuracy, precision, or recall when AdaBoost.M1 fails to produce higher metric values than the base learner. Author Keywords: AdaBoost, Boosting, Classification, Class-Specific Thresholds, Machine Learning, Outliers
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- Workplace Bullying in Ontario Healthcare Settings
- This thesis builds on scholarship that highlights how expected gender roles serve to both normalize and obscure forms of violence and hostility in health care workplaces. An analysis of 25 labour arbitrations involving cases of bullying reveals how gender relations is a factor in these grievances and relevant policies in Ontario health care facilities. Reinforced by underlying expectations around women as nurturing and men as aggressive, responses to bullying are found to reflect and reproduce embedded gendered power inequalities in labour. While bullying in the workplace is often treated in policy discussions as an individual and identity-neutral phenomenon, this research provides evidence to the contrary. As a consequence, we must interrogate existing legislation and policies, asking how we can develop approaches that account for, respond to, and mitigate the causes of bullying rooted in unequal power relations, including gendered ones. Author Keywords: gender, health care, labour arbitration, policy, workplace bullying, workplace harassment
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- Know*ledge Constellations and Re*constellating
- The purpose of this study was to explore the educational implications of a clearer understanding of the practice of using multiple, including Indigenous, knowledges when finding solutions to place-based environmental issues. The impetus for my research came from a growing sense of urgency to address environmental issues within both Indigenous and non-Indigenous communities. Some have argued that communities will be most successful in understanding and resolving such issues if ways can be found to work with different knowledges. However, the practice of bringing together multiple knowledges is not yet consistently effective. At the same time, there is a recognised need for individuals who are able to use different knowledges to address urgent environmental concerns. Unfortunately, there is minimal programming advice based on the perspective of individual practitioners available to guide post-secondary institutions wishing to meet this need. This lead to my first two research questions: What are the key principles and concepts in a narrative describing how individual practitioners think about using knowledges when finding solutions to place-based environmental issues? and What are the implications of this understanding for teaching and learning, especially in post-secondary Indigenous-and-Environmental education? In my project, I used a relational research approach that led to a third question: How is a complexity-inspired interpretive approach suitable for exploring these questions? I had coherent conversations with sixteen practitioners who were deliberately using multiple, including Indigenous, knowledges to find solutions to place-based environmental issues. Practitioners and I co-created a Know*ledge Constellation Story to describe how they think about using knowledges in their work. In a group coherent conversation with five educators who were familiar with Indigenous-and-Environmental education, we explored the educational implications of this story. Together, we finalised a Teaching-Learning Story of Re*constellating and identified ways to prepare students to practice re*constellating, including teaching strategies and program considerations. The Know*ledge Constellation Story and the Teaching-Learning Story of Re*constellating will inform post-secondary Indigenous-and-Environmental education. Graduates from such programs will be better prepared to engage with communities to address environmental concerns, meet legislative and policy requirements, and support research efforts that would benefit from a clearer understanding of the practice of re*constellating. Author Keywords: Complexity-Inspired Interpretive Approach, Conditions of Emergence, Indigenous-and-Environmental Education, Know*ledge Constellations, Principles of Re*constellating, Teaching and Learning
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- Mythopoeia Sylvatica
- Since British colonization of North America and the beginning of Anglo-speaking Euro-Canada and the United States, myth-making or representations of the forests have witnessed degradation and loss of old-growth forest ecosystems or intact sylvan landscapes. Canadian and American versions of the story of the North American Forests shared the same trajectory: forests as ‘wasted-land’ or the sylvan wilderness (terra nullius) divided into properties and cleared to “improve” the land for settlement/agriculture, forests as storehouses for timber and imperial expansion, forest landscapes and specific forest trees as identity politics and sources of industrial and economic power. While forests are recognized according to various stakeholders’ values today, what is commonly accepted as a forest varies widely. The meaning given to “forest” determines related terms and concepts, such as “sustainable forestry” and “reforestation.” This thesis addresses the issue of social-bioecological degradation, loss, and dis(re)membering of old-growth forests and problematizes traditional Western relationships with old wildwoods shaped by notions of space, politics, and economy. In the forest topos, the core question becomes which forest(s) are being imagined, represented, and remembered? Whose environmental imagination is shaping the landscape? As a critical topographical exploration of the North American forests through six witness trees, this thesis demonstrates how the meanings imbued in trees and wild woods come to determine the fate of the forests. It reveals how colonial values and trends persist in our societies still, and calls for an ethical social-ecological reimagining of the forests through traditions of ethical storytelling and environmental witnessing. Author Keywords: critical topography, environmental generational amnesia, environmental witnessing, forests, social-ecological systems, witness trees
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- Stopover Movement Patterns by Blackpoll and Canada Warblers Across Southeastern Canada During Fall Migration
- Stopover ecology is a topic that surges in relevancy as choices made by migrants during stationary periods (stopover sites) may not only have important individuals’ fitness consequences but also can affect population dynamics. I used MOTUS automated telemetry array to study fall stopover duration of Blackpoll Warbler (BLPW) and departure decisions of BLPW and Canada Warbler (CAWA) in relation to various predictors. I affixed radio-transmitters on 55 BLPWs and 32 CAWAs at two banding stations in Ontario in September-October 2014-2015. Radio-tagged individuals were tracked through the MOTUS network across southeastern Canada. I developed models relating age class, fat score, Julian date and stopover movement types to Blackpolls’ stopover duration. I also examined whether there were species-related differences of wind selectivity when resuming migration. No explanatory variable significantly influenced BLPW’s stopover duration. Both species tended to depart under increased tailwind assistance, but with no difference in the effect of wind conditions between the two species. This study provides further evidence supporting the relevance of local wind conditions as a key factor affecting the departure likelihood, especially when migrating birds face an ecological barrier. Author Keywords: Cardellina canadensis, departure decisions, minimum stopover length, MOTUS, overland fall migration, Setophaga striata
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- 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
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- Regulation of Cytokinins During Kernel Development in High and Low Yielding Oat and Barley Lines
- Cytokinins (CKs) are a family of plant phytohormones responsible for many areas of plant growth and development. There are four free base types of CKs found in higher plants, trans-zeatin (tZ), N6-(∆2-isopentenyl)adenine (iP), cis-Zeatin (cZ) and dihydrozeatin (DZ). CK biosynthesis is regulated by adenosine phosphate-isopentenyltransferase (IPT), which is encoded by a multi-gene family in many plant species. There are two types of IPT pathways responsible for CK production, the tRNA pathway and the AMP (ATP/ADP) pathway. The tRNA pathway putatively produces cZ and the latter predominantly produces iP type nucleotides. CKs have long been studied for their role in stress tolerance, signal transduction, and involvement in many areas of plant growth and development. This study focuses on the role of CKs and CK biosynthesis by IPT during kernel development and comparisons of its regulation in high and low yielding barley and oat lines. The sequence of a putative IPT encoding gene in barley and oat was identified by a blast search of other known IPT gene fragments in closely related species. Quantitative Real time PCR results based on primers designed for the putative barley and oat IPT gene revealed changes in expression of IPT during different stages of kernel development, but no significance difference was associated with yield. Correlation of IPT gene expression in barley with cZ CK profiles measured by HPLC-MS/MS, confirms a putative IPT gene is a tRNA- IPT. HPLC-MS/MS results reveal some CK types, such as benzyladenine, are more predominant in higher yielding lines. This suggests different types of CKs play a role in yield production. Future studies on more IPT genes in the barley and oat IPT gene family will outline a more clear representation of the role of IPT in barley kernel development. Author Keywords: Benzyladenine, Cereal grain, Cytokinin, Isopentenyl Transferase, Mass Spectrometry, Real Time PCR
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- Time-dependent effects of predation risk on stressor reactivity and growth in developing larval anurans (Lithobates pipiens)
- The predator vs. prey dynamic is an omnipresent factor in ecological systems that may drive changes in life history patterns in prey animals through behavioural, morphological, and physiological changes. Predation risk can have profound effects on the life history events of an animal, and is influenced by the neuroendocrine stress response. Activation of the hypothalamic-pituitary-adrenal/interrenal axis, and the induction of stress hormones (e.g., corticosterone (CORT)) have been shown to mediate the onset of inducible anti-predator defensive traits including increased tail-depth, and reduced activity. The predator-prey relationship between dragonfly nymphs and tadpoles can be a powerful model system for understanding mechanisms that facilitate changes in the stress response in accordance with altered severity of risk. It has been well demonstrated early in tadpole ontogeny that increased corticosterone (CORT) levels, observed within three weeks of predator exposure, are correlated with increased tail depth morphology. However, the reactivity of the stress response in relation to the growth modulation in developing prey has yet to be fully explored. Accordingly, this thesis assessed the stress and growth response processes in tadpoles that were continuously exposed to perceived predation risk later in ontogeny. Continuous exposure of prey to predation risk for three weeks significantly increased CORT levels, and tail depth. However, tadpoles exposed to six weeks of predation risk acclimated to the presence of the predator, which was observed as a significant reduction of stressor-induced CORT levels. In addition, although increased tail depth has been attributed to predator defense, predator-naïve tadpoles began to display similar tail depth morphology as treated tadpoles at the six week time point. Thus, this thesis suggests that the stress response in lower vertebrate systems (e.g., tadpoles) may operate in a similarly complex manner to that observed in higher vertebrates (e.g., rats), for which severity of risk associated with the stressor aids in defining activity of the stress response. Moreover, the lack of morphological difference between treatments among tadpoles exposed later in ontogeny suggests that the mechanisms for inducing defenses are normal morphological traits in the development of the animal. This thesis paves the way for future research to elucidate the relationship between the neuroendocrine stress response and hormonal pathways involved in growth modulation in the presence of environmental pressures. Author Keywords: Acclimation, Corticosterone, Growth Modulation, Predation Risk, R. pipiens, Tadpole
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- third wheel
- Population cycles are regular fluctuations in population densities, however, in recent years many cycles have begun to disappear. With Canada lynx this dampening has also been seen with decreasing latitude corresponding to an increase in prey diversity. My study investigates the role of alternate prey on the stability of the lynx-hare cycle by first comparing the functional responses of two sympatric but ecologically distinct predators on a primary and alternate prey. I then populated a three species predator-prey model to investigate the role of alternate prey on population stability. My results showed that alternate prey can promote stability, though they are unlikely to “stop the cycle”. Furthermore, stability offered by alternate prey is contingent on its ability to increase intraspecific competition. My study highlights that population cycles are not governed by a single factor and that future research needs to be cognizant of interactions between alternate prey and intraspecific competition. Author Keywords: alternate prey, Canis latrans, functional response, Lepus americanus, Lynx canadensis, Tamiasciurus hudsonicus
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- Executive Function as a Predictor of Emotional, Behavioural, and Social Competence Problems in Children with Epilepsy
- The study aimed to examine the association between different components of executive function (EF) and emotional, behavioural, and social competence problems (EBSP) in children with epilepsy. Although there is evidence of an association between EBSP and EF in typically developing children, little research has examined this relation in children with epilepsy. The sample comprised of 42 children with epilepsy, aged 6.0 to 18.1 years old. Results showed that EBSP were associated with EF in these children; however, different components of EF were related to different EBSP. Shifting was a significant predictor of emotional, behavioural, and social competence problems in children with epilepsy, whereas inhibition was a significant predictor of behavioural problems. This suggests that children with epilepsy, with different EF profiles may be at-risk for developing different types of problems. These results may aid researchers and clinicians with the development of new techniques to identify and treat children with EBSP. Author Keywords: behavioural problems, emotional problems, epilepsy, executive function, social competence
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- Mutation of the B10 Tyrosine and E11 Leucine in Giardia intestinalis Flavohemoglobin
- The flavohemoglobin in Giardia intestinalis (gFlHb) is the only known protozoan member of a protein class typically associated with detoxifying nitric oxide (by oxidation to nitrate) in bacteria and yeast. Mutants of the B10 tyrosine (Y30F) and E11 leucine (L58A), conserved residues thought to influence ligand binding, were expressed and studied using Resonance Raman (RR) spectroscopy. In the wild type protein, RR conducted using a carbon monoxide probe detects two distinct Fe-CO stretches associated with two different active site configurations. In the open configuration, CO does not interact with any polar side chains, while in the closed configuration, CO strongly interacts with one or more distal residues. Analysis of the Y30F mutant provided direct evidence of this tyrosine’s role in ligand stabilization, as it had only a single Fe-CO stretching mode. This stretching mode was higher in energy than the open conformer of the wild type, indicating a residual hydrogen bonding interaction, likely provided by the E7 glutamine (Q54). In contrast the L58A mutant had no effect on the configurational nature of the enzyme. This was unexpected, as the side chain of L58 sits atop the heme and is thought to regulate the access of distal residues to the heme-bound ligand. The similar spectroscopic properties of wild type and L58A suggest that any such regulation would involve rapid conformational dynamics within the heme pocket. Author Keywords: B10 Tyrosine, Catalytic Globin, E11 Leucine, Flavohemoglobin, gFlHb, Giardia intestinalis