Graduate Theses & Dissertations

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Understanding the establishment of Typha spp. in North America using population genetics and common garden studies
There are three cattail (Typha) taxa in Canada: T. latifolia (native), T. angustifolia (introduced), and their hybrid T. x glauca. The latter is invasive in regions around the Laurentian Great Lakes, and I investigated the potential role that commercial suppliers may be playing in the introduction of non-native Typha by comparing genotypes of North American, European, and commercially available plants. I found that Ontario garden centres are importing both hybrids and non-native lineages of T. angustifolia into Canada, but was unable to identify the provenance of T. latifolia. I also investigated the possibility that the hybrid cattail leaf litter shade and leachate influences germination and early growth of the parental species of the hybrids. Using three common garden experiments, I found that T. x glauca leaf litter suppresses germination rates of the three taxa. In the early seedling growth experiment, plant performance varied by taxa, and for the competition experiment there were no intra- or interspecific competition or treatment effects on the performance of plants. Overall, my research identified a potential mechanism allowing T. x glauca to dominate wetlands, and also shows that non-native lineages are being introduced into Canada through commercial trade Author Keywords: Competition, Germination, Non-native lineages, Plant nurseries, Seedling Growth, Typha spp.
"Multimodal Contrast" from the Multivariate Analysis of Hyperspectral CARS Images
The typical contrast mechanism employed in multimodal CARS microscopy involves the use of other nonlinear imaging modalities such as two-photon excitation fluorescence (TPEF) microscopy and second harmonic generation (SHG) microscopy to produce a molecule-specific pseudocolor image. In this work, I explore the use of unsupervised multivariate statistical analysis tools such as Principal Component Analysis (PCA) and Vertex Component Analysis (VCA) to provide better contrast using the hyperspectral CARS data alone. Using simulated CARS images, I investigate the effects of the quadratic dependence of CARS signal on concentration on the pixel clustering and classification and I find that a normalization step is necessary to improve pixel color assignment. Using an atherosclerotic rabbit aorta test image, I show that the VCA algorithm provides pseudocolor contrast that is comparable to multimodal imaging, thus showing that much of the information gleaned from a multimodal approach can be sufficiently extracted from the CARS hyperspectral stack itself. Author Keywords: Coherent Anti-Stokes Raman Scattering Microscopy, Hyperspectral Imaging, Multimodal Imaging, Multivariate Analysis, Principal Component Analysis, Vertex Component Analysis
Isotopes of the Caribbean
This research represents the first stable carbon and nitrogen isotope analysis of human bone collagen (n = 29) from the Escape Site (AD 300 - 1000), Saint Vincent. As a two-pronged investigation, this research had the following goals: (1) determining the ideal pretreatment for poorly preserved bones and (2) reconstructing the Escape Site sample population diet. By incorporating powdered specimens, shorter demineralizations and increased acid:sample exposure, higher collagen yields were produced, thereby expanding the sample size for isotopic analysis. Notably, the elemental data suggests that not all isolated collagen was biogenic and was perhaps contaminated by non-collagenous proteins. This highlighted the importance of using multiple criteria to rigorously evaluate collagen based on the full quality indicator profile. In the end, 5 individuals yielded useable isotope data which was consistent with a broad spectrum diet relying primarily on C3 plants as well as terrestrial, reef, nearshore and freshwater fauna. Within the broad region, the Escape Site data was comparable to other islands from the Lesser Antilles and Cuba emphasizing the influence of regional biodiversity as well as the likelihood that the studied population contributed and benefitted from the extensive Saladoid trade networks which existed at the time. Author Keywords: Caribbean, Collagen, Escape Site, Human diet, Saladoid, Stable isotope analysis
relationship of policy aims and implementation
Background: Ontario’s Ministry of Health and Long Term Care (MOHLTC) claims people with mental illnesses/addictions need improved care/overuse emergency departments. MOHLTC expects Coordinated Care Planning (CCP, teams of mental/physical health professionals, social workers and informal caregivers) to improve care and lower emergency department returns/healthcare costs. CCPs are directed by policies, Smith’s “problematics,” or Deleuze’s “expressions,” supposedly reflecting “contents”/“everyday worlds.” Research Question: How do Ontario health/allied professionals come together with a person with mental illness/addictions and informal caregiver(s) to address health needs through a CCP? Method: 1) Analyzed CCP policies; generated questions about creation/implementation. 2) Interviewed eight professionals about interpreting/enacting policies. 3) Connected interview data to policies. Findings: Opportunities for fragmentation exist in gaining consent; determining eligibility; persons in care, informal caregivers and professionals’ participation; person-centeredness; “shame-free” environments; health literacy; records of medications. Conclusion: CCP participants need to minimize fragmentations which takes time, space, money; creates contradictions in lowering costs/improving care. Author Keywords: Addiction, Dual Diagnosis, Health Care Policy, Institutional Ethnography, Integrated Health Care, Mental Illness
Ethnoarchaeology in the Traditional Villages of Bagan, Myanmar
This thesis investigates the current composition of traditional settlements located in and around the remains of the ancient, walled and moated, regal-ritual epicenter of Bagan, Myanmar. This study also provides some suggestions as to strategies that may be employed by future settlement archaeology projects in the region. To achieve the aims of this study, an ethnoarchaeological approach was employed at ten village sites located on the Bagan plain: Thè Pyin Taw, Thè Shwe Hlaing, Zee Oo, Kon Sin Kyi, Kon Tan Gyi, Minnanthu, Hpauck Sein Pin, Thah Tay Kan, East Pwa Saw, and West Pwa Saw. The data obtained from these villages, compounds, and houses is used to generate a version of the average Bagan village, compound (i.e., house lot), and house. The model Bagan village, compound, and house are in turn used to provide the basis for suggestions to be used in future settlement archaeology projects. Author Keywords: Ancient Tropical Societies, Bagan, Ethnoarchaeology, Myanmar, Settlement Archaeology, Southeast Asia
Merit-Making and Monuments
Bagan, Myanmar’s capital during the country’s Classical period (c. 800-1400 CE), and its surrounding landscape was once home to at least four thousand monuments. These monuments were the result of the Buddhist pursuit of merit-making, the idea that individuals could increase their socio-spiritual status by performing pious acts for the Sangha (Buddhist Order). Amongst the most meritous act was the construction of a religious monument. Using the iconographic record and historical literature, alongside entanglement theory, this thesis explores how the movement of labour, capital, and resources for the construction of these monuments influenced the settlement patterns of Bagan’s broader cityscape. The findings suggest that these monuments bound settlements, their inhabitants, and the Crown, in a variety of enabling and constraining relationships. This thesis has created the foundations for understanding the settlements of Bagan and serves as a useful platform to perform comparative studies once archaeological data for settlement patterning becomes available. Author Keywords: Bagan, Entanglement, Religious Monuments Buddhism, Settlement Patterns, Southeast Asia
effects of heat dissipation capacity on avian physiology and behaviour
In endotherms, physiological functioning is optimized within a narrow range of tissue temperatures, meaning that the capacity to dissipate body heat is an important parameter for thermoregulation and organismal performance. Yet, experimental research has found mixed support for the importance of heat dissipation capacity as a constraint on reproductive performance. To investigate the effects of heat dissipation capacity on organismal performance, I experimentally manipulated heat dissipation capacity in free-living tree swallows, Tachycineta bicolor, by trimming feathers overlying the brood patch, and monitored parental provisioning performance, body temperature, and offspring growth. I found that individuals with an enhanced capacity to dissipate body heat (i.e., trimmed treatment) provisioned their offspring more frequently, and reared larger offspring that fledged more consistently. Although control birds typically reduced their nestling provisioning rate at the highest ambient temperatures to avoid overheating, at times they became hyperthermic. Additionally, I examined inter-individual variation in body temperature within each treatment, and discovered that body temperature is variable among all individuals. This variability is also consistent over time (i.e., is repeatable), irrespective of treatment. Further, I found that individuals consistently differed in how they adjusted their body temperature across ambient temperature, demonstrating that body temperature is a flexible and repeatable physiological trait. Finally, I used a bacterial endotoxin (lipopolysaccharide) to examine the regulation of body temperature of captive zebra finches (Taeniopygia guttata) during an immune challenge. Exposure to lipopolysaccharide induces sickness behaviours, and results in a fever, hypothermia, or a combination of the two, depending on species and dosage. I asked what the relative role of different regions of the body (bill, eye region, and leg) is in heat dissipation/retention during the sickness-induced body temperature response. I found that immune-challenged individuals modulated their subcutaneous temperature primarily through alterations in peripheral blood flow, particularly in the legs and feet, detectable as a drop in surface temperature. These results demonstrate that the importance of regional differences in regulating body temperature in different contexts. Taken together, my thesis demonstrates that heat dissipation capacity can affect performance and reproductive success in birds. Author Keywords: body temperature, heat dissipation, tree swallow, zebra finch
Flavohemoglobin expression in Giardia intestinalis exposed to nitrosative stress
The parasitic protist Giardia intestinalis lacks most heme proteins yet encodes a flavohemoglobin (gFlHb) that converts nitric oxide to nitrate and likely protects the cell from nitrosative stress. In this work an antibody raised against gFlHb was used to examine both changes in gFlHb expression levels and intracellular localization in Giardia in response to nitrosative stress. Giardia trophozoites exposed to stressors which either directly release nitric oxide (diethyltriamine NONOate, 1 mM) or are sources of other reactive nitrogen intermediates (sodium nitrite 20 mM or S-nitrosoglutathione, 1 or 5 mM) exhibited a 2 to 9-fold increase of gFlHb after 24 hours. Increased expression levels of gFlHb were detectable by 8 hours in S-nitrosoglutathione and diethyltriamine-NONOate-treated trophozoites, and by 12 hours after sodium nitrite exposure; these differences were likely due to differences in the rates of release of RNS from these compounds. In addition to a band of the expected size for gFlHb (52 kDa), western blots detected a second, higher molecular weight band (72 kDa) with comparable or higher intensity upon treatment with these RNS donors, which is consistent with sumoylation of gFlHb. Immunofluorescence microscopy of Giardia trophozoites detected gFlHb diffused throughout the cytoplasm and more punctuated staining along the cell membrane and between the nuclei. The punctuated staining may be due to the association of gFlHb with either peripheral vacuoles or basal bodies. Author Keywords: Flavohemoglobin, Giardia intestinalis, Nitrosative stress
Gratitude is in our nature
Although a wealth of research supports nature’s beneficial effects on well-being, a lack of attentiveness and appreciation for nature may prevent people from fully experiencing nature’s benefits. A mindfulness-based nature intervention was tested across two studies to investigate whether gratitude and mindfulness can boost nature’s effects for well-being. Students completed activities across a one-week (Study 1; N = 129) and two-week (Study 2; N = 130) intervention. Students in both studies experienced significant declines in positive and negative emotion over time. Study 1 did not show the expected increases in gratitude and connection to nature. Study 2 found that students who simply spent time in nature experienced fewer negative emotions and greater increases in trait gratitude than those who were asked to gratefully reflect on their natural surroundings. Both studies found positive correlations between trait gratitude, mindfulness, well- being and connection to nature. Implications and suggestions for future research are discussed. Author Keywords: Gratitude, Intervention, Mental Heath, Mindfulness, Nature, Well-being
Understanding the Role of Lived Experience in Community Leaders’ Vision and Governance of Economic Development and Sustainability in Rurally Situated Small Cities
Sustainable development is normative - making decisions in the present that construct the experience of place for the future. It is primarily driven by global measures developed to meet the needs of the present while ensuring future generations can meet their own needs. These measures attempt to balance economic prosperity, social justice, and environmental stewardship in many nations. This attempt to balance a plurality of outcomes creates socio-political tensions in choosing between alternatives. These barriers and tensions are characterized through the neoclassical vision of: economics as a science, utility maximization, and alienation of people. This thesis explores the lived experience of community leaders in Peterborough, Ontario as they navigate a contentious and current debate of where to relocate a casino in the region. The results focus on the tension experienced by community leaders as they seek to balance elements of care, while preserving neoclassical values of growth, individualism, freedom of choice, and interconnectedness. The thesis concludes with a model that works towards an understanding of the role of lived experience in economic development decision-making in rurally situated small cities, and recommendations for further research and policy recommendations. Author Keywords: economic development, governance, lived experience, small city, sustainable development, vision
Reconciliation as Relationship
In 2015, Canada’s Truth and Reconciliation Commission called upon Canadians to reconcile relationships between Settlers and Indigenous peoples in Canada. Education for reconciliation is one important element of this process. However, critical questions arise when education is undertaken by and for Settlers such as myself: Are our undertakings actually fostering reconciliation? According to whom? Drawing from reconciliation theory and decolonizing Indigenous methodologies, a reconciliation methodology is created to consider this question in the context of three reconciliation workshops for Settlers. Indigenous perspectives and pedagogies are prioritized. The emerging understandings of reconciliation as relationship and relationship as pedagogy reframe some prevailing Settler thinking about reconciliation, unmask latent assumptions linked to the colonial habits of mind and affirm the need for personal responsibility in the reconciliation relationship. The Indigenous norm of learning in-relation is found to be a powerful experience for Settlers participants offering valuable insights for reconciliation education in Canada. Author Keywords: decolonizing, education, Indigenous, relationship, Settler, Truth and Reconciliation
Investigation of Using Phase Change Materials for Thermal Energy Storage in Adiabatic Compressed Air Energy Storage
There is an increasing global need for grid scale electrical energy storage to handle the implementation of intermittent renewable energy sources. Adiabatic compressed air energy storage is an emerging technology with similar performance to pumped hydro except it has the issue of heat loss during the compression stage. Previously, it has been considered to use sensible heat storage materials to store the heat created by compression in a thermal energy storage unit until energy is required, and then transfer the heat back to the air. This research proposes to instead use phase change materials to store the heat of compression, as this will reduce entropy generation and maximize roundtrip exergy efficiency. Different configurations and placements of the phase change materials are considered and exergy analyses are presented. The thermodynamic equations are derived and optimal setup conditions including amount of latent heat and melting temperatures are calculated. Author Keywords: Compressed Air Energy Storage, Energy Storage, Exergy, Phase Change Materials

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Graduate student theses produced at Trent University. You may also browse theses and dissertations by year, program, or author.

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