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Flavohemoglobins are enzymes primarily implicated in nitrosative stress due to their high nitric oxide (NO) dioxygenase activity and transcriptional upregulation in response to NO. Giardia intestinalis assemblages A, B, and E possess flavohemoglobins (gFlHb) that may function beyond their NO dioxygenase activity, potentially contributing to oxidative stress regulation, as transcriptional profiling revealed that peroxide also induces gFlHb expression. This study investigates gFlHb's NADH oxidase activity in the absence of NO, structural interactions with lipids, and response to reactive oxygen species. Minor differences in NADH oxidase activity among assemblages were observed, and their susceptibilities to inhibition were assessed to evaluate gFlHb as a potential therapeutic target against Giardia infection. Under aerobic conditions, we observed that gFlHb generates hydrogen peroxide, a surprising finding suggesting a self-regulating feedback mechanism involving reactive oxygen species and heme degradation. These findings provide new insight into the role of flavohemoglobins in microaerotolerant parasites like Giardia.

Author Keywords: flavohemoglobin, Giardia intestinalis, heme, hydrogen peroxide, NADH, oxidative stress

Transracial adoption places the child with a family of a different ethnicity than their own. In the current study we qualitatively examine concerns associated with transracial adoption and investigate the relation between parent-child relationships and child social-emotional problems. Twenty-two adopted girls from China, 20 nonadopted Caucasian girls, and 23 nonadopted Chinese-Canadian girls, between 10-14 years, and their mothers were included. Thematic content analysis of interviews with adoptive mothers revealed that the transracial adoption experience had positive, negative, and neutral aspects. This included the parent-child relationship, the adopted child's view of their physical appearance, and the incorporation of cultural elements into the home. Quantitative analyses revealed no significant differences between the three groups on measures of parent-child relationship quality and child social-emotional functioning, which confirmed findings from the qualitative analysis. In the entire sample there were significant negative relations between quality of parent-child relationship and social-emotional functioning. These results suggest that early age of adoption may help decrease the likelihood of problematic parent-child relationships and social-emotional functioning in adopted children. It would be important to re-examine this question during adolescence when racial identity forms.

Author Keywords: Cultural Socialization, Developmental Psychology, Parent-Child Relationship, Social-Emotional Behaviour, Transracial Adoption

DNA methylation (DNAm) is a useful indicator of phenotypic expression and diversity, and can potentially inform adaptations to environmental changes. This thesis uses epigenetic techniques to investigate the mechanisms underlying phenotypic variation in white-tailed deer, black bear, and mountain goat, with a particular focus on age and body size. In the second chapter, we aimed to contribute to wildlife monitoring by developing epigenetic clocks, or predictive models of age, and diagnostic markers of age class and sex. In the third chapter, we aimed to investigate the involvement of DNAm in body size variation of white-tailed deer by developing a model predictive of hindfoot length, and by identifying CpGs and genes that may be involved in hindfoot length variation. My results indicate that DNAm is an effective predictive marker of various phenotypes in these North American large mammals, and that epigenetic methods offer valuable insights for managing human impacts on wildlife.

Author Keywords: Age, Body Size, DNA Methylation, Epigenetics, Phenotypes, Population Genetics

A new regime governing cannabis production, distribution, and access came into effect across Canada in 2018. With the passing of the Cannabis Act (2018) a new legal cannabis industry began taking shape across the country, with specific manifestations at the local and provincial levels. In this study, I take up the standpoint of people who use cannabis and explore how access is organized under this new regulatory regime. Following a new-materialist informed institutional ethnographic mode of inquiry, I draw on interviews, observations, and texts to describe the work processes through which three distinct materializations of cannabis are produced: cannabis for medical purposes, retail cannabis products, and cannabis as a corporate good. My analysis then reveals how these materializations are organized according to discourses of medicalization, commercialization, and corporatization in ways that curtail the full liberatory potential of this policy change.

At its core my research is an investigation into the operations of the cannabis industry in Ontario, Canada – currently one of the largest legal cannabis markets in the world. My intent is not to provide a view of the functioning of the industry as a whole. Rather, it is to tease out key operations, including medical access programs, product selection and testing practices, and knowledge practices, and explore both their impacts on people who use cannabis and what insights they hold for reorganizing access to other controlled substances. Importantly, my research demonstrates how state actors and corporate entities remain the main beneficiaries of legalization, which I argue is the result of an over-reliance on state regulation over community organization as the schema for enacting a public health approach to drug policy. While cannabis legalization may not have realized its full liberatory potential in this country, it has offered an invitation to reconsider the criminalization of previously controlled substances and how we might regulate these substances in new ways. In the conclusion to this work I take up this invitation, building on my findings to imagine what the organization of cannabis access outside current ruling relations could look like and how we might cultivate care-full relations of drug access more broadly.

Author Keywords: Canada, Cannabis, Drugs, Institutional Ethnography, New Materialisms, Policy

Indigenous children and youth have been exposed to educational institutions and curricula that are detrimental to their identity and cultural journey. This thesis explores the importance of educational institutions and curriculums complementing the needs of Indigenous students during their time in compulsory and post-secondary education. Five self-identifying Indigenous students attending Trent University share their educational experiences using sharing circles. Following this, the findings are analyzed, and recommendations for educational policies are discussed.

Author Keywords: Colonization, Indigenization, Indigenous education, Indigenous identity

The diversification of mammals has been shaped by climatic fluctuations and geological changes over millions of years. Among them, shrews (Soricidae) stand out as one of the most diverse mammalian lineages. Shrews are found on most continents and have evolved remarkable adaptations at the species and population levels. Although evolutionary studies of shrews have been limited by a lack of genomic resources, this work aimed to address this gap by developing such resources and using various omics approaches to explore adaptation and divergence in shrews, with a particular focus on an isolated population on Bon Portage Island (BPI), Nova Scotia, Canada. BPI shrews exhibit distinctive foraging habits and possess a unique allele for a dietary enzyme, which may represent an adaptation to their specialized diet. My research involved assembling and annotating de novo genomes from three shrew species. In Chapter 2 I conducted a comparative genomic analysis of 20 mammals (including four shrew species) to identify lineage-specific adaptations including accelerated regions, gene family expansions, and positively selected genes. I found shrew-specific variants in genes associated with the nervous, metabolic, and auditory systems, which may underlie some of their unique traits. In Chapter 3, I examined morphological and epigenetic divergence between mainland and island populations of masked shrews (Sorex cinereus), including BPI. Island shrews exhibited smaller body sizes and signs of accelerated biological aging, marked by DNA methylation differences enriched in developmental and digestive pathways. Chapter 4 focused on analyzing genome-wide SNP data to identify regions of differentiation, alongside RNA-seq data to perform a differential gene expression analysis between BPI shrews and other populations. The results from both analyses revealed patterns of differentiation in genes associated with fatty acid metabolism and metabolic regulation that are likely linked to their specialized, largely marine-based diet. Additionally, I reconstructed the demographic history of Nova Scotia masked shrew populations, revealing that the divergence of the BPI population appears to coincide with rising sea levels following the last glacial maximum. These findings shed light on mechanisms of adaptation and divergence, illustrating how ecological pressures, geographic isolation, and dietary specialization shape genomic, epigenomic, and transcriptomic landscapes.

Author Keywords: comparative genomics, epigenetics, genome assembly, island syndrome, population genomics, transcriptomics

In electron-doped ferroelectrics, the free electrons can become concentrated along the domain walls which act like a conducting surface. We consider the impact of free electrons occupying the t2g orbitals on the domain walls of an electron-doped perovskite ferroelectric. We build an analytical model based on Landau-Ginzburg-Devonshire theory, and a trio of tight-binding Hamiltonians for free electrons. We self-consistently solve for the polarization, potential, and electron density using a finite-difference approximation. We find that the ferroelectric is effectively charge neutral. The free electrons are attracted to the positively-charged domain wall, leaving it with a small residual charge. As the electron density increases, the domain walls tilt to form zig-zag domain walls. Orbital selectivity of the t2g orbitals depends on the relative orientations of the orbital plane and the domain wall. This property influences the rate at which the domain wall tilts as a function of the electron density.

Author Keywords: Charged Domain Wall, Domain Wall, Ferroelectric, Landau-Ginzburg, Perovskite, Strontium Titanate

Calcium (Ca) limitation and sodium chloride (NaCl) toxicity tolerance are potential controllers of Daphnia populations. D. pulicaria neonates collected from 14 Kawartha Highland lakes were exposed to 6 Ca concentrations (0.5-5.0 mg Ca L-1) over 6 days. We did not find differences in maximum mass-specific growth rate or half-maximum thresholds between source lakes. Growth rates were reduced <1.5 mg Ca L-1, and there was a significant interaction between Ca and source lake lineage. We also compared log-logistic NaCl dosage models estimating 48-hour lethal concentration (LC)10, LC25, and LC50 by exposing 9 clones to 10 concentrations, 18-2700 mg Cl L-1. Survivorship decreased >1500 mg NaCl L-1, and there were differences between lake lineage LC50 estimations. This suggests our D. pulicaria genotypes may not have experienced extreme enough selection pressure from either stressor to develop local adaptation, but allele variability between lakes may explain differences in NaCl toxicity and Ca limitation responses.

Author Keywords: Calcium, Daphnia, Mass Specific Growth Rate, Sodium Chloride, Toxicity, Zooplankton

Recovery of forest soils from chronic acidification can be enhanced with the use of non-industrial wood ash (NIWA). Non-industrial wood ash is alkaline and contains high concentrations of macronutrients, but trace metal concentrations must be evaluated to limit risk of metal toxicity following application. Additionally, understanding how different forest ecosystem components respond to NIWA is essential to inform current policy regulating its use as a soil amendment. This study evaluated the response of sugar maple (Acer saccharum) sap yield and chemistry, the response of soils beneath maple, American beech (Fagus grandifolia) and mixed species canopies, and maple and beech fine roots, foliage, seedling abundance, and understory vegetation abundance and composition to an application of 6 Mg ha-1 NIWA. Eight 40 x 40 m plots were established in a hardwood stand in Bracebridge, Ontario and were sampled prior-to and up to two years following application of NIWA (n = 4). Non-industrial wood ash significantly increased organic horizon soil pH and macronutrient (Ca, Mg, and K) concentrations with increases in Mg and K extending to the mineral soils. Significantly higher concentrations of some trace metals (Al, Fe, Mn, Cd, Cu, Pb, Zn) were also observed, but these were restricted to the organic horizons. Sugar maple sap, pH, and sweetness were unaffected by NIWA application, and while increases were observed in nutrient and metal concentrations in sap, the differences were small and variable between years, and all concentrations were consistent with those commonly found in maple sap. Fine root biomass of maple and beech trees was not affected by NIWA application, but higher concentrations of K and Mg were observed in the roots of both species, consistent with higher concentrations observed in the mineral soil horizons beneath both species' canopies. Only significant increases were observed in K in sugar maple foliage. Both critical foliar concentrations and diagnosis and recommendation integrated system (DRIS) norms for sugar maple did not indicate mineral nutrient deficiencies at this site; although this site was acidic and nutrient-poor, this may account for the lack of differences observed, particularly between species. Changes observed in understory vegetation were driven by years rather than between treatments. These results suggest that moderate doses of NIWA can provide significant decreases in soil acidity and increase nutrient availability, with limited increases in metal concentrations that are primarily restricted to the organic horizons.

Author Keywords: American beech, metal toxicity, Non-industrial wood ash (NIWA), sap sweetness, sap yield, sugar maple

The significance of nursing retention in today's healthcare system is more prominent than ever before. The purpose of this study was to answer the question: What do Registered Nurses understand about their intention to stay at Ontario rural hospitals? A qualitative descriptive phenomenological approach was used to conduct this study. Ten Registered Nurses from rural hospitals were interviewed regarding their experiences working in rural hospitals. Seven themes were developed including: Sense of Community, Pride and Identity, Weight of Responsibility, Feeling Alone, Questioning Commitment, Rural Reality, and Feeling Misunderstood. Participants shared that their nursing co-workers were the reason they continued to stay working in their rural hospitals, with the essence of the themes being we are there for each other. The findings of this study can be used to influence nursing practice, nursing education, healthcare leaders, and areas of future research.

Author Keywords: Nurses, Retention, Rural