Graduate Theses & Dissertations

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Islands, ungulates, and ice
Central to wildlife conservation and management is the need for refined, spatially explicit knowledge on the diversity and distribution of species and the factors that drive those patterns. This is especially vital as anthropogenic disturbance threatens rapid large-scale change, even in the most remote areas of the planet. My dissertation examines theinfluence of land- and sea-scape heterogeneity on patterns of genetic differentiation, diversity, and broad-scale distributions of island-dwelling ungulates in the Arctic Archipelago. First, I investigated genetic differentiation among island populations of Peary caribou (Rangifer tarandus pearyi) in contrast to continental migratory caribou (Rangifer tarandus) and evaluated whether genetic exchange among Peary caribou island populations was limited by the availability of sea ice – both now and in the future. Differentiation among both groups was best explained by geodesic distance, revealing sea ice as an effective platform for Peary caribou movement and gene flow. With future climate warming, substantial reductions in sea ice extent were forecast which significantly increased resistance to caribou movement, particularly in summer and fall. Second, I assessed genetic population structure and diversity of northern caribou and deciphered how Island Biogeography Theory (IBT) and Central Marginal Hypothesis (CMH) could act in an archipelago where isolation is highly variable due to the dynamics of sea ice. Genetic differentiation among continental and island populations was low to moderate. In keeping with IBT and CMH, island-dwelling caribou displayed lower genetic diversity compared to mainland and mainland migratory herds; the size of islands (or population range) positively influenced genetic diversity, while distance-to-mainland and fall ice-free coastlines negatively influenced genetic diversity. Hierarchical structure analysis revealed multiple units of caribou diversity below the species level. Third, I shifted my focus to the terrestrial landscape and explored the elements governing species-environment relationships. Using species distribution models, I tested the response of caribou and muskoxen to abiotic versus abiotic + biotic predictors, and included distance to heterospecifics as a proxy for competitive interactions. Models that included biotic predictors outperformed models with abiotic predictors alone, and biotic predictors were most important when identifying habitat suitability for both ungulates. Further, areas of high habitat suitability for caribou and muskoxen were largely disjunct, limited in extent, and mainly outside protected areas. Finally, I modelled functional connectivity for two genetically and spatially disjunct groups of island-dwelling caribou. For High Arctic caribou, natural and anthropogenic features impeded gene flow (isolation-by-resistance); for Baffin Island caribou we found panmixia with absence of isolation-by-distance. Overall, my dissertation demonstrates the varying influences of contemporary land- and sea-scape heterogeneity on the distribution, diversity and differentiation of Arctic ungulates and it highlights the vulnerability of island-dwelling caribou to a rapidly changing Arctic environment. Author Keywords: Circuitscape, connectivity, Island Biogeography, landscape genetics, population structure, species distribution models
Particulate Matter Component Analyses in Relation to Public Health in Canada
This thesis explores the shot-term relationship between exposure to ambient air pollution and human health through metrics such as mortality and hospitalization in Canada. We begin by detailing the organization and interpolation of air pollution data from its partially quality-controlled source form. Analyses of seasonal, regional and temporal trends of all major components of PM2.5, was performed, showing a seasonal variation across most regions and validating the dataset. A one-pollutant statistical Generalized Additive Model was applied to the data, estimating the health risk associated with exposure to thirteen different components of PM2.5. The selected components were based on those that compromised the majority of the mass and included: sulphate, nitrate, zinc, silicon, iron, nickel, vanadium, potassium, organic carbon, organic matter, elemental carbon, total carbon. Trends based on annual estimates of the association for PM2.5, and its constituents,were compared, showing that carbonaceous compounds, sulphate and nitrate had similar estimates of association. Many estimates, as is common in population ecologic epidemiology, had association estimates statistically indistinguishable from zero, but with clear features of interest, including evident differences between cold and warm season associations in Canada's temperate climate. A method to model two correlated pollutants (in this case, PM2.5 and O3) was developed using thin plate splines. In this approach, the location of the response surface (after accounting for the temperature, a smooth function of time and day of week) that corresponds to the average pollutant concentration and the average plus one unit was used as the estimate of the joint contribution of pollutants due to a unit increase. The estimates from the thin plate spline (TPS) approach were compared to the single pollutant models, with large increases and decreases in PM2.5 and O3 being captured in the TPS estimates. However, this approach indicated significantly larger error in the estimates than would be expected, indicating a possible future area for refinement. Author Keywords: Air pollution, Environmental Epidemiology, Generalized Additive Models, Human Health, Multivariate Models, Thin Plate Splines
Determinants of Breeding Bird Diversity in Ontario's Far North
190 species of birds are known to breed in Ontario’s far north making the region an important nursery for boreal birds. Digital point count data were collected using two different autonomous recording units (ARUs): one model with two standard microphones to detect birds and anurans, and one model with one standard microphone and one ultrasonic microphone for detecting bats. ARUs were deployed either in short or long-term plots, which were four to six days or approximately 10 weeks, respectively. I assessed differences in breeding bird richness detections between ARU and plot types. I also tested the relative impact of the habitat heterogeneity and species-energy hypotheses in relation to breeding birds and created predictive maps of breeding bird diversity for Ontario’s far north. I found no difference in species richness estimates between the two ARU models but found that long-term plots detected about 7 more bird species and 1.5 more anuran species than short-term plots. I found support for both the species-energy and habitat heterogeneity hypotheses, but support for each hypothesis varied with the resolution of the analysis. Species-energy models were better predictors of breeding bird diversity at coarser resolutions and habitat heterogeneity models were better predictors at finer resolutions. Breeding bird diversity was highest in the Ontario Shield Ecozone compared with the Hudson Bay Lowlands Ecozone, but concentrated areas of higher diversity found in the Lowlands were associated with large rivers and the associated coastlines. Author Keywords: boreal birds, breeding birds, habitat heterogeneity, Hill diversity, Ontario, species-energy hypothesis
Use and Utilization of Loose and Commingled Human Dental Remains in Investigations of Ancient Human Populations
Commingled teeth present a unique opportunity for a novel application of standard methodological approaches commonly utilized in dental anthropological studies. Unfortunately, little research has been conducted on loose or commingled dental assemblages to determine if they are suitable samples for reconstructing bioarchaeological narratives of ancient human populations. The lack of research on commingled dental samples is surprising, given that teeth are highly resistant to post-depositional deterioration and are often some of the only remains left in high deteriorated burials. An experimental analysis of a commingled dental assemblage recovered from four chultuns at Ka'kabish, Belize, was conducted to address this lack of research and provide a real-world example of the potential use and utilization of commingled dental assemblages in investigations of ancient human populations. Author Keywords: Anthropology, Belize, Commingled, Dental, Maya, Methods
Forest Roost Use by Little Brown Bats (Myotis lucifugus) in Ontario
Roosts offer bats protection from predators, shelter from external environmental conditions, and a space where sociality, mating, and the rearing of young can occur. However, knowledge gaps still remain for many forest roosting species, such as the little brown bat (Myotis lucifugus) surrounding what roosts are selected, and what variables are influential at differing scales of selection. As a species-at-risk, identifying and predicting roost habitat selection may aid conservation and management. I identified forest roosts in a previously unexamined area of this species’ range using radio-telemetry, and measured tree-scale characteristics of located roosts. I then used a logistic model selection process with stand-scale variables to predict roost presence across forest stands. Height of trees in a given stand was the best predictor of roost presence - which may be linked to solar exposure and other thermal benefits. I then examined roost-level variables effecting the abundance of roosting bats in an artificial roosting environment (bat boxes). I found that temperature and social effects were both significant predictors of bat abundance, with warmer minimum temperatures in the box having a positive effect. These results suggest maternal bats may select roosts with higher minimum temperatures, likely due to the energetic benefits that may be gained over the course of reproduction. Author Keywords: forest roost, habitat selection, little brown bat, Myotic lucifugus, roost choice, stand selection
ADHD Symptomatology Across Adulthood
Objective: To improve on several methodological issues and research gaps regarding current literature investigating the stability of ADHD symptomatology across adulthood and relationships between the two core ADHD symptom dimensions (i.e., inattention and hyperactivity-impulsivity) and multiple life outcomes in adults. Method: A large sample of postsecondary students were initially assessed for ADHD symptomatology using the Conners’ Adult ADHD Rating Scale (CAARS). Six years later, academic success was assessed using students’ official academic records (e.g., final GPAs and degree completion status), and fifteen years later, participants were re-assessed using the CAARS and several measures of life success (e.g., relationship satisfaction, career satisfaction, and stress levels). Results: Inattention and hyperactivity-impulsivity symptoms showed strong stability across the 15-year period. Additionally, greater inattention symptoms during emerging adulthood and early middle adulthood were consistently associated with poorer life success (e.g., lower GPAs, poorer relationship and career satisfaction), particularly for men. Associations for hyperactivity-impulsivity symptoms were less consistent. Conclusion: ADHD symptomatology can be conceptualized as a stable, dimensional trait across adulthood, with robust associations with measures of life success. Author Keywords: academic success, ADHD, adults, job satisfaction, relationship satisfaction, stability
From Cultural Barriers to Educational Breakthroughs
This study examines critical pedagogy as a novel approach to diversity, equity and inclusion (DEI) education at Peterborough Police Service (PPS). To begin, the present study examines hypermasculinity and isolationism as cultural traits in policing that serve as barriers to DEI education. Later, results of focus groups with PPS members that investigated negative and positive experiences with DEI training, barriers to meeting DEI education outcomes and, perceived goals of future DEI education at PPS are discussed. Drawing from findings from the literature review and focus groups, this thesis argues that critical pedagogy offers a useful framework to explore divisive subjects like systemic racism, power and privilege, colonialization, etc. and contributions of police in maintenance of the status quo. Raising the critical consciousness of PPS members by unveiling systems of domination may provide a starting point for enhancing police service to groups that are racialized and minoritized. Education of this kind may also involve a reconceptualization of the role of police as allies to marginalized communities. Author Keywords: Community, Critical Pedagogy, Diversity, Education, Police, Police Culture
Along the Path
This thesis is written in three parts and supported throughout by feminist critical pedagogical analysis and a narrative methodological approach. In Part I I lay a theoretical groundwork that weaves the Freirean roots of critical pedagogy with its more contemporary theories in application to K-12 schooling, and with feminist thinking, most notably Sara Ahmed whose work has moved me both as a human and a teacher. In Part II, I take a deep dive into autoethnography (Bochner, (2017), Ellis, 1999). In Part III, I offer a memoir of my experience as a classroom teacher over a nearly 20 year period. The story of my work as an activist elementary school teacher oscillates between phases of hope and despair around the potential for forwarding a broad range of social and ecological justice ends through teaching and learning in the Ontario public school system. Finally, in Part IV, I return to conceptual analysis to reflect on the key themes of my memoir including teacher burnout, teacher efficacy, teacher resilience, and the ways in which these interact with teacher learning communities, school cultures and the relationships that underpin the work of teachers and educators. Author Keywords: Activist, Autoethnography, Critical Pedagogy, Resilience, Social-Change, Teaching
Relationships between bird densities and distance to mines in Northern Canada
Increased mining activity in the Canadian Arctic has resulted in significant changes to the environment that may be influencing some tundra-nesting bird populations. In this thesis I examine the direct and indirect effects of mining on birds nesting in the Canadian Arctic. I first perform a literature review of the effects that mining in the Arctic has on northern environments and wildlife and outline several ways in which mines affect Arctic-breeding birds. By using the Program for Regional and International Shorebird Monitoring (PRISM) Arctic plot-based bird survey data from across the Canadian Arctic, collected from 1995 to 2018, I identify the effects of distance to mining operations on the occupancy patterns of Arctic-breeding bird species. Six species’ densities were significantly impacted by mine proximity (Canada/Cackling Goose, Long-tailed Duck, Long-tailed Jaeger, Pectoral Sandpiper, Savannah Sparrow, and Rock Ptarmigan) across five major mine sites. Each species has its own unique relationship to distance from mining activity. Author Keywords: Bird populations, Canadian Arctic, Mining, Mining activities, PRISM, Tundra-nesting birds
Electrochemical versus Chemical Oxidation of Bulky Phenols
Phenolic compounds are used in industry, such as agriculture and biotechnology, and inevitably end up in our environment. These compounds may serve as a phenolic precursor to produce raw materials for a wide range of applications. Chemical oxidation has been the common synthetic pathway to oxidize phenols and related compounds. However, traditional chemical approaches suffer from use of harsh chemicals, waste generation, and lack of reaction selectivity. Electrochemical synthesis has emerged as an alternative method to mitigate common challenges associated with organic synthesis. Herein, electrochemical oxidation of 2,6-diphenylphenol (DPP) and 2,2-dihydroxybiphenol (DHBP) was carried out and compared to traditional chemical oxidation. Contrasted with chemical oxidation, cyclic voltammetry of DPP resulted in a range of products based on the specific potential ranges used, whereas chemical oxidation of DHBP yield a dark-coloured polymeric product. The electrooxidation and chemical oxidation of DPP and DHBP resulted in a solution colour change, indicative of the formation of new, but different products monitored by UV-vis, and characterized by nuclear magnetic spectroscopy (NMR), X-ray single crystal diffraction, IR spectroscopy, transmission electron microscopy (TEM), and gas chromatography-mass spectrometry (GC-MS). The data indicate that the synthetic outcomes are dependent on the synthetic methodology employed, and that electrooxidation and chemical oxidation can form products unique to the pathway utilized. Author Keywords: chemoselectivity, electrochemistry, phenols, radical, synthesis
Internationalized Crusade
The outbreak of the Spanish Civil War in July 1936 divided national public opinions throughout the West. One of the factors behind such split was religious beliefs. This was the case for the United States and Ireland where Francisco Franco’s rebels got significant public support. This work argues that both the Irish and American Catholic Church hierarchies and laity Catholics’ support of the Nationalists had dramatic effects domestically. This thesis expands previous scholarship on the Spanish Civil War by utilizing primary sources from both American and Irish archives to understand the intention, forms, and controversy of Irish and American Catholics’ support of the Nationalists. Author Keywords: Anti-clericalism, Catholicism, Clergy, De Valera, FDR, Spanish Civil War
Genetic Networks to Investigate Structure and Connectivity of Caribou at Multiple Spatial and Temporal Scales
Understanding genetic structure, connectivity, and movement of a species iscritical to management and conservation. Genetic network approaches allow the analysis of genetic information with flexibility and few prior assumptions. In chapter one, I tested the ability of individual-based genetic networks to detect fine-scale structure and connectivity in relation to sampling efforts. My findings revealed individual-based genetic networks can detect fine-scale genetic structure of caribou when using 15 highly variable microsatellite loci. Sampling levels less than 50% of the estimated population size resulted in highly disconnected networks which did not allow for accurate structure analysis; however community detection algorithms were robust in grouping closely related individuals despite low sampling. In chapter two, I used individual-based and population-based genetic networks to investigate structure, connectivity, and movement of caribou across a large study area in Western Canada. A community detection algorithm partitioned the population-based genetic network at multiple spatial scales which uncovered patterns of hierarchical genetic structure and highlighted patterns of gene flow. The hierarchical population structure results aligned with the known distribution of different caribou Designatable Units (DUs) and additional structure was found within each DU. Furthermore, individual-based networks that were constructed with a subset of samples from the Mackenzie Mountains region of the Northwest Territories revealed patterns of long-distance movement and high connectivity across the region. Author Keywords: Biological Conservation, Caribou, Community Detection, Connectivity, Genetic Networks, Structure

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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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