Graduate Theses & Dissertations

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Stable Isotope Analysis of Archaeological Faunal Remains From the Middle Trent Valley, Ontario
A sample of faunal remains (n=129) from seven archaeological sites located on Pigeon and Rice Lakes, Ontario were sampled and analyzed for the stable carbon and nitrogen isotopic composition of bone collagen. These samples date from the Archaic to Late Woodland and include 35 different animal species. The goal of this research was to investigate the isotope ecology of the Middle Trent Valley and characterize the degree to which isotope ratios varied across space and time between different lakes, as wells as variation within and between species. There were no statistically significant differences in the Middle Trent Valley δ13C or δ15N according to space and time. As such, the isotope data for all archaeological sites were combined to construct an isotope food web for the Middle Trent Valley and compared to Katzenberg’s (1989) food web. These isotope data provide some insight into the dynamic interplay between local ecosystems, and anthropogenically modified landscapes in Ontario. Author Keywords: carbon, food web reconstruction, human-animal relations, Middle Trent Valley, nitrogen, Stable isotope ecology
Statistical Analysis of the Hidden Patterns Found in the Burial Customs of MM/MH III – LM/LH IIIA1 Mainland Greece and Knossos
This study explores different ways of interpreting mainland and Knossian burial customs and assessing the manner in which they were used to explore themes of political and social status. In order to complete this study, correspondence analysis was applied to 98 tombs from Bronze Age (1700-1360 BCE) Knossos, Pylos, and Mycenae. Through the use of CA 14 hidden clusters and two hypotheses were generated and then analyzed in order to answer the following three research questions: can traditional explanations for the changes seen in Final Palatial Knossian burial customs be challenged; does the nature of Final Palatial burial customs support the theory of a mainland invasion; and can these patterns inform us about Knossian, Pylian, and Mycenaean society and the manners in which burials were used for social and political display. By answering these questions it became possible to understand Knossian, Pylian, and Mycenaean societies and their diverse uses of burial customs to display social and political status. Author Keywords: Burial Customs, Correspondence Analysis, Final Palatial Period, Mortuary Studies, Mycenaean Crete
Stoichiometric food quality affects responses of Daphnia to predator-derived chemical cues
While both resource quality and predator-derived chemical cues can each have profound effects on zooplankton populations and their function in ecosystems, the strength and nature of their interactive effects remain unclear. We conducted laboratory experiments to evaluate how stoichiometric food quality (i.e., algal carbon (C):phosphorus (P) ratios) affects responses of the water flea, Daphnia pulicaria, to predator-derived chemical cues. We compared growth rates, body elemental content, metabolic rates, life history shifts, and survival of differentially P-nourished Daphnia in the presence and absence of chemical cues derived from fish predators. We found effects of predator cues and/or stoichiometric food quality on all measured traits of Daphnia. Exposure to fish cues led to reduced growth and increased metabolic rates, but had little effect on the elemental content of Daphnia. Elevated algal C:P ratios reduced growth and body %P, increased respiration, and increased body %C. Most of the effects of predator cues and algal C:P ratios of Daphnia were non-interactive. In contrast, the declines in daphnid survival and related population growth rates that arose because of poor food quality were amplified in the presence of predator-derived cues. Our results demonstrate that stoichiometric food quality interacts with anti-predator responses of Daphnia, but these effects are trait-dependent and appear connected to animal life-history evolution. Author Keywords: Daphnia, ecological stoichiometry, indirect predator effects, life history, phosphorus, predator-prey relationships
Stop Making Sense
ABSTRACT There is a growing number of juvenile novels and picture books that mean to educate the reader about synaesthesia. The synaesthete in these texts for young readers desires to be a social agent, yet sh/e also considers synaesthesia to be a healing power and a deeply personal psychedelic form of escapism; I argue that the synaesthete in these texts `uses' their synaesthesia to dissipate emotional trauma caused by pubescent uncertainty and social isolation. In this thesis, I propose that YA and Children's texts that feature synaesthesia generally reinforce the discursive constraints of normative perception, and they also promulgate the assumption that synaesthesia is an extraordinary form of cognition instead of a legitimate subject position. Author Keywords: Authenticity, Liminality, Repesentation, Synaesthesia, Synesthesia, Zizek
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
Story is Medicine
This is a story within a story that spans over a hundred years and four generations. It takes the reader from war-torn Russia during a famine to the urban streets of Toronto and then to the Canadian North. The story is a memoirette, or a ‘not quite long enough, but almost a memoir’ of a mother’s journey navigating life after her son discloses his addiction to Fentanyl. The mother finds little if any support from family, friends or conventional support programs and instead turns to her oma’s harrowing stories of survival as a source of knowledge, strength and medicine. The analysis explores storytelling as a legitimate method of learning, pedagogy and research. It explores the concept of story as medicine through Etuaptmumk. A Two-Eyed Seeing framework created by Mi’kmaq elders in 2004 (Sylliboy, Latimer, Marshall & McLeod, 2009). The power of the narrative is discussed through ‘Western’ and ‘Indigenous’ lenses. Author Keywords: addiction, Etuaptmumk, Fentanyl, story as medicine, story as pedagogy, Two-Eyed Seeing
Stress Axis Function and Regulation in New World Flying Squirrels
Across vertebrate taxa, the hypothalamic-pituitary-adrenal axis (or the stress axis) is highly conserved, and is central to vertebrate survival because it allows appropriate responses to psychological stressors. Habitat shapes successful physiological and ecological strategies, and to appreciate how individual species respond to stressors in their environment, it is essential to have a thorough knowledge of the basic stress physiology of each species. In this dissertation, I studied the functioning and evolution of the stress physiology of New World flying squirrels. I showed that baseline, circulating cortisol levels in northern (Glaucomys sabrinus) and southern (G. volans) flying squirrels are some of the highest ever reported for mammals, indicating that their stress axes operate at a higher set point than most other species. I also assessed other aspects of their acute stress response, including free fatty acid and blood glucose levels, and indices of immune function, and showed that the flying squirrels’ physiological reaction to stressors may differ from that of other mammals. Using immunoblotting, I found that corticosteroid-binding globulin (CBG) expression levels in flying squirrels appeared to be higher than previously reported using alternative methods. I also concluded however, that these levels did not appear to be high enough to provide their tissues with the protective CBG-bound buffer from their high circulating cortisol concentrations experienced by the majority of vertebrates. Thus, this arm of cortisol regulation within the flying squirrel stress axes may be weak or non-existent. Following this, I focused on southern flying squirrels and showed evidence that the second arm of cortisol regulation — the negative feedback mechanism at the level of the brain — functions effectively, but that this species is glucocorticoid resistant. Their tissue receptors appear to have a reduced affinity for cortisol, and this affinity may change seasonally to allow for the onset of other biological processes required for survival and reproduction. Due to their distinctive stress physiology, northern and southern flying squirrels may provide comparative physiologists with model systems for further probing of the function and evolution of the stress axis among vertebrates. Author Keywords: corticosteroid-binding globulin, flying squirrel, Glaucomys, glucocorticoids, physiological ecology, stress physiology
Student's Bell Tower
The university newspaper is a vital aspect of the university public, as it provides a platform for students to voice their opinions on topics pertaining to the culture of their university and gives students critical information about what is happening on campus. This thesis uses the University of Regina’s The Carillon as a case study to evaluate how university newspapers interact with and influence their publics. In Chapter One, I detail the history of The Carillon, and how the radical atmosphere of the 1960s influenced the newspaper’s growth. In Chapter Two, I explore how The Carillon uses facets of digitality—such as their website, multimedia, and social media—to increase its readership. The chapter examines how these digital platforms reach The Carillon’s publics more efficiently, but still adhere to the traditions established by the newspaper from its inception. Finally, in Chapter Three, I assess the success of university newspapers which have transitioned to a strictly digital presence. For this assessment, I use the University of Alberta’s The Gateway and the University of Prince Edward Island’s The Cadre as case studies, and argue that The Carillon can learn from these digital newspapers to become more effective in using digital media to reach its student public. Altogether, this study of university newspapers offers a guide on how to maintain a balance between materiality and digitality, while also preserving the university newspaper’s legacy and traditions. Author Keywords: Digitality, Journalism, Materiality, Publics, The Carillon, University Newspapers
Studies of the Giardia intestinalis trophozoite cell cycle
To study the Giardia intestinalis cell cycle, counterflow centrifugal elutriation (CCE) was used to separate an asynchronous trophozoite culture into fractions enriched for cells at the different stages of the cell cycle. For my first objective, I characterized the appearance of a third peak (Peak iii) in our flow cytometry analysis of the CCE fractions that initially suggested the presence of 16N cells that are either cysts or the result of endoreplication of Giardia trophozoites. I determined that this third peak consists of doublets of the 8N trophozoites at the G2 stage of the cell cycle that were not removed effectively by gating parameters used in the analysis of the flow cytometry data. In the second objective, I tested the use of a spike with RNA from the GS isolate of Giardia as an external normalizer in RT-qPCR on RNA from CCE fractions and encystation cultures of Giardia from the WB isolate. My results showed that the GS RNA spike is as effective as the use of previously characterized internal normalizer genes for these studies. For the third objective, I prepared two sets of elutriation samples for RNA seq analysis to determine the transcriptome of the Giardia trophozoite cell cycle. I confirmed the results of the cell cycle specific expression of several genes we had previously tested by RT-qPCR. Furthermore, our RNA-seq identified many genes in common with those identified from a microarray analysis of the Giardia cell cycle conducted by a collaborator. Finally, I observed an overall <4 fold change in differentially expressed genes during the G1/S and G2/M phase of the cell cycle. This is a modest change in gene expression compared to 10 - 30 fold changes for orthologous genes in mammalian cell cycles. Author Keywords: Cell cycle, Counterflow Centrifugal Elutriation, Flow Cytometry, RNA-sequencing, RT-qPCR
Study of Aerosols for use in Water Remediation of Pharmaceutical Pollutants
In this thesis, aerosolization was studied as a possible means of water remediation for several environmentally relevant pharmaceutical pollutants, known for their persistence in wastewater effluent and potable water sources. Seven different pharmaceutical compounds and a well-known plasticizer were all shown to decrease considerably in concentration in aerosol that was produced and subsequently collected within a short time span. Strong evidence is presented that an enhanced rate of partitioning into the gas phase at the air-water interface of water droplets exists for every compound tested relative to that occurring in bulk solution. UV photolysis in aerosols was also explored and shown for sulfamethoxazole to be at least an order of magnitude faster in aerosols then in bulk solution. The implications towards both the environmental fate, and removal of these compounds from water sources is discussed. Author Keywords: Aerosols, Air-water partitioning, Pharmaceuticals, Photolysis, Sulfamethoxazole
Supercritical Water Chemistry
Supercritical water (SCW) exhibits unique properties that differentiates it from its low temperature behaviour. Hydrogen bonding is dramatically reduced, there is no phase boundary between liquid and gaseous states, heat capacity increases, and there is a drastic reduction of the dielectric constant. Efforts are underway for researchers to harness these properties in the applications of power generation and hazardous waste destruction. However, the extreme environment created by the high temperatures, pressures and oxidizing capabilities pose unique challenges in terms of corrosion not present in subcritical water systems. Molecular Dynamics (MD) simulations have been used to obtain mass transport, hydration numbers and the influence on water structure of molecular oxygen, chloride, ammonia and iron (II) cations in corrosion crevices in an iron (II) hydroxide passivation layer. Solvation regimes marking the transitions of solvation based versus charge meditated processes were explored by locating the percolation thresholds of both physically and hydrogen bonded water clusters. A SCW flow through reactor was used to study hydrogen evolution rates over metal oxide surfaces, metal release rates and the kinetics for the oxidation of hydrogen gas by oxygen in SCW. Insights into corrosion phenomena are provided from the MD results as well as the experimental determination of flow reactor water and hydrogen chemistry. Author Keywords: Flow Studies, Molecular Dynamics, Supercritical Water
Support Vector Machines for Automated Galaxy Classification
Support Vector Machines (SVMs) are a deterministic, supervised machine learning algorithm that have been successfully applied to many areas of research. They are heavily grounded in mathematical theory and are effective at processing high-dimensional data. This thesis models a variety of galaxy classification tasks using SVMs and data from the Galaxy Zoo 2 project. SVM parameters were tuned in parallel using resources from Compute Canada, and a total of four experiments were completed to determine if invariance training and ensembles can be utilized to improve classification performance. It was found that SVMs performed well at many of the galaxy classification tasks examined, and the additional techniques explored did not provide a considerable improvement. Author Keywords: Compute Canada, Kernel, SDSS, SHARCNET, Support Vector Machine, SVM

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Format: 2024/03/03