English

Using rodent models, it is possible to study the behavioural and physiological outcomes of early life stress and the influences on normal mammary gland development and carcinogenic risk. Results demonstrate that the experience of three weeks of prolonged maternal separation (LMS; 4 hrs/day) increased the susceptibility of adult, but not pubertal, female BALB/c mice to engage in higher levels of depressive-related immobility behaviour and lower levels of active floating (a suggested adaptive coping behaviour) in the acute forced swim test, than offspring that experienced three weeks of brief separation (BMS; 15 min/day) events. Despite the increased immobility behaviour, adult LMS female offspring demonstrated lower basal corticosterone levels relative to BMS females. However, the experience of chronic early-life stress, regardless of the length, results in greater changes between non-stressed and stressed corticosterone levels (i.e. stressor reactivity) in adult females compared to their male counterparts. These changes were associated with decreased glucocorticoid receptor and coactivator-associated arginine methyltransferase 1 protein expression in mammary gland of female LMS mice at young adulthood, highlighting potential mechanisms underlying their heightened risk of mammary tumourigenesis. These data suggest that early life environments can induce behavioural and physiological alterations observed in adulthood, which may have an influence on the likelihood of malignancies developing in the breast.

Author Keywords: coping, early life stress, mammary gland development, mother-infant interactions, steroid receptors, stressor reactivity

This dissertation seeks to explore and understand how autism, asperger and the autistic spectrum is represented in Canadian culture. Acknowledging the role of films, television, literature and print media in the construction of autism in the consciousness of the Canadian public, this project seeks to critique representations of autism on the grounds that these representations have an ethical responsibility to autistic individuals and those who share their lives. This project raises questions about how autism is constructed in formal and popular texts; explores retrospective diagnosis and labelling in biography and fiction; questions the use of autism and Asperger's as metaphor for contemporary technology culture; examines autistic characterization in fiction; and argues that representations of autism need to be hospitable to autistic culture and difference. In carrying out this critique this project proposes and enacts a new interdisciplinary methodology for academic disability study that brings the academic researcher in contact with the perspectives of non-academic audiences working in the same subject area, and practices this approach through an unconventional focus group collaboration. Acknowledging the contribution of disability studies approaches to representation, this project will also challenge these methodologies on the grounds that the diverse voices of audiences are, at times, absent from discourse focused research. Chapter One offers an explanation of disability studies scholarship and the history of autism as a category of disability and difference. Chapter Two looks at how disability and specifically autistic representations have been understood academically and introduces the rationale and experiences of the focus group project. Chapter Three explores retrospective, biographical diagnosis, the role of autism as technological metaphor, and contemporary biography. Chapter Four looks at the construction of autistic characters in Canadian literature and film. Chapter Five interrogates documentary and news media responses to autism and the construction of autism as Canadian health crisis, and also explores how discourses that surround autism are implicated in interventions and therapeutic approaches to autistic individuals.

Key Terms

Autism; Autistic Spectrum; Asperger; Disability; Representation; Media; Interdisciplinary Research; Focus Group; Retrospective Diagnosis; Biography; Academic Method; Academic and Representational Responsibility; Literature; Film; Diagnosis; Disability Studies; Therapy

Author Keywords: Academic Method, Autism Spectrum, Biography, Disability, Interdisciplinary Research, Representation

Many facilities attempt to alleviate the risk of chronic stress in captivity by providing environmental enrichment shown to minimize behavioural disorders and stress in several species. One potential form of enrichment used in zoos is training animals to perform rides for guests, however, the effect of this activity on the welfare of individual animals has never been examined. I validated the use of saliva for assessing stress in dromedary camels (Camelus dromedarius) an animal commonly used for rides. I then measured variation in salivary cortisol in four male camels during animal rides for guests at the Toronto Zoo. The camels were sampled during the ride season (from June to August) using four treatments: 1) in their pasture, 2) at the ride area not performing rides, 3) performing a low number of rides (n=50/day) and 4) performing a high number of rides (n=150/day). Furthermore, samples were taken before and after the ride season for comparison. There was a significant difference between the post-ride season treatment and the three treatments involving guest presence during the ride season (ride area, low rides, high rides. This indicates that performing rides is not a stressful experience based on the stress metrics I used, and suggests that rides may be a form of enrichment for dromedary camels.

Author Keywords: ACTH challenge, animal welfare, camels, environmental enrichment, salivary cortisol, stress

The objective of this thesis was to assess the influence of anthropogenic sulphur (S) and nitrogen (N) deposition, and harvesting on soil acidity and calcium (Ca2+), magnesium (Mg2+), potassium (K+) and N soil pools in plantation forest soils in Ireland. The response to reductions in anthropogenic S deposition was assessed using temporal trends in soil solution chemistry at two long-term monitoring plots--one on a blanket peat, the other on a peaty podzol. At the peat site, there was little evidence of a response to reductions in throughfall non marine sulphate (nmSO₄2-) and acidity; soil water acidity was determined by organic acids. In addition, temporal variation in soil water did not respond to that in throughfall. In the podzol, reductions in anthropogenic S and H+ deposition led to a significant improvement in soil water chemistry at 75 cm; pH increased and total aluminum (Al_tot) concentrations declined. The impact of harvest scenarios on exchangeable Ca2+, Mg2+ and K+ pools was assessed using input-output budgets at 40 sites (30 spruce, 10 pine). Harvest scenarios were stem-only harvest (SOH), stem plus branch harvest (SBH) and stem, branch and needle harvest (whole-tree harvesting; WTH). Average K+ and Mg2+ budgets were positive under these scenarios. However, exchangeable K+ pools were small and due to uncertainty in K+ budgets, could be depleted within one rotation. Average Ca2+ budgets for spruce were balanced under SOH, but negative under SBH and WTH. Nitrogen deposition was high, between 5 and 19 kg N ha-1 yr-1, but was balanced by N removal in SOH. However, N budgets were under SBH and WTH, indicating that these harvesting methods would lead to depletion of soil N over the long-term. Finally, monitoring of N cycling at a spruce plot indicated that N deposition was contributing to large NO₃- leaching, and as such the site was N saturated. However, N cycling did not fit the criteria of the N saturation hypothesis; instead leaching was directly related to N deposition and supported the model of kinetic N saturation.

Author Keywords: acidic deposition, base cations, input-output budgets, Ireland, nitrogen, whole-tree harvesting

The last two decades have seen thousands of Canadian university graduates go to teach English in places such as China, South Korea, and Japan. In this thesis, drawing on Clandinin and Connelly's concept of narrative inquiry, I situate the stories I heard about the experiences of 15 teachers who taught English as a Second Language in South Korea between 2003 and 2012.

While my interviewees expressed intrinsically personal reasons for taking on such temporary professional employment, they also acknowledged that they felt somewhat forced to do so by an increasingly bleak job market at home. I position their decisions in the neoliberal employment context in Canada over the past two decades, highlighting the personal and socioeconomic factors that influenced them to take up such opportunities. Additionally, I examine how these experiences shifted their views of Canada and what it meant to be Canadian, both while they were away and upon their return home by revealing the contradictions between expectation and the lived realities of young Canadians. These contradictions unmask the deceptive nature of dominant narratives in Canadian society.

Author Keywords: Canadian Identity, Canadian Job Market, Narrative, Neoliberalism, Teaching Abroad

Despite - or perhaps because of - her popularity as a best-selling poet, the work of Mary Oliver has been minimized and marginalized within the academy. Nevertheless, Oliver's readership is an expansive and devout one made up of a wired yet insular North American public in search of reconnecting with the natural world. I propose that through Oliver's poetry readers access the affective, sensory responses to nature first encountered during childhood. This return to "the child" is deliberately used by various publics to share communal goals. Drawing from such frameworks as ecocritical and trauma theory, I explore environmental memory, ecstatic places, and the sensuousness of nature and language to consider ways in which diverse publics claim and use Oliver's work. I provide a close reading of selections of Oliver's poems to argue that her work's appeal speaks to a revived perception of the necessity of nature to the human spirit

Author Keywords: Attentiveness, Childhood, Language, Mary Oliver, Nature Poetry, Senses

The present study examined the role of multiple nights of sleep in the consolidation of a complex motor learning task. Participants were 24 Trent undergraduates, 12 in the learning group (Mage = 20.33, SD = 1.87, 10 female) and 12 in the control group (Mage = 21.92, SD = 3.42, 7 female). Participants underwent 5 consecutive nights of polysomnographic recordings, with a Rock Band learning session on the third night. A series of 2(group)x4(night) ANOVAs were performed on the sleep variables. Interactions were found in the number of spindles detected at Pz, F(333) = 9.19, p <.01, and in the density of spindles detected at Pz, F(3,33) = 4.06, p <.05. The pattern of changes from baseline was significantly different between the two groups; spindles increased in the learning group and decreased in the control group. The novel finding was that spindle number/density remained elevated at the third post-learning night of sleep.

Author Keywords: Motor Learning, Procedural Memory, Sleep, Sleep Spindles

I investigated the impact of beef-cattle farm management on the reproductive success of Bobolink (Dolichonyx oryzivorus) and Eastern Meadowlark (Sturnella magna) within Eastern Ontario. I monitored rotational grazing management regimes and hay cut dates while assessing breeding phenology and reproductive success of Bobolinks and Eastern Meadowlarks. In pasture paddocks the major factor determining Bobolink reproductive success was the date that cattle entered a paddock to graze, with earlier entries resulting in lower reproductive success. On a landscape scale, within a series of paddocks grazed by a single herd, as the number of paddocks grazed during the nesting season increased, the number of Bobolinks that reproduced successfully decreased. Experimental quantification of trampling showed that cattle exposure to clay pigeon targets, regardless of stocking rates, resulted in the majority of targets being trampled. In hayfields associated with beef- cattle operations, grassland birds had a higher likelihood of success when cutting occurred after 4 July. The best method to improve the reproductive success of Bobolinks and Eastern Meadowlarks is to leave some hayfields and pasture paddocks undisturbed until nesting is complete.

Author Keywords: Bobolink, Dolichonyx oryzivorus, farm management, hayfield, pasture, rotational grazing

Sexual reproduction in flowering plants depends on investment in reproduction, the mode of pollen transfer, the availabilities of nutrient resources and potential mates, and the spatial scales over which these processes take place. In this thesis, I studied the general reproductive biology of Shepherdia canadensis (L.) Nutt. (Elaeagnaceae) and the suite of pollinators that visit the plants in Ivvavik National Park, Yukon, Canada. Across ten sites, I found that S. canadensis females were larger than males, but males produced more flowers than females at most sites. Males typically occurred at higher frequencies than females with the average male to female sex ratio being 1.19 ± 0.08 (mean ± SE, n = 10 sites). Both shrub size and flower production were significantly influenced by interactions between soil nitrogen and sex. Insect visitors to S. canadensis flowers were primarily ants and flower flies (Syrphidae), but exclusion experiments indicated that visitation by flying insects yielded greater fruit production than visitation by crawling insects. I found that fruit set was limited by the density of males within populations, but only over small distances (4-6 m). This is the first study to demonstrate that female reproductive success of a generalist-pollinated dioecious plant is limited by the density of males over small spatial scales.

Author Keywords: dioecy, pollinators, sex ratio, sexual dimorphism, Shepherdia canadensis

The Serial Discontinuity Concept describes the downstream recovery of key biophysical variables below an impoundment. With the proliferation of hydropower dams to meet increasing societal demands, further refinement and understanding of the Serial Discontinuity Concept is needed to accurately predict downstream impacts and ensure the proper management of rivers. In this study, I examine SDC predictions on physical, chemical and biological recovery in regulated rivers providing evidence from 1) a comprehensive literature review and 2) a formal test using two regulated rivers in Northern Ontario. I specifically address how these changes are reflected in benthic invertebrate abundance, diversity, and community composition. The literature review and case studies support the predicted recovery of temperature, periphyton, substrate, and drift. In addition, the study suggests that two recovery gradients exist in regulated rivers: 1) a longer, thermal gradient taking up to hundreds of kilometres downstream; and 2) a shorter, resource subsidy gradient recovering within 1-4 km downstream of an impoundment. Total benthic invertebrate abundance varies considerably and depends on the degree of flow alteration and resource subsidies from the upstream reservoir. In contrast, benthic diversity is reduced below dams irrespective of dam location and operation with little recovery observed downstream. Contrary to SDC predictions, the longitudinal gradient in regulated rivers is not a compaction of functional changes seen over several stream orders in natural rivers but a response to dam design and reservoir conditions. Stoneflies and dragonflies are particularly sensitive to regulation while filter feeding invertebrates are enhanced. Ward and Stanford's (1983) Serial Discontinuity Concept is still a useful framework for testing hypotheses. Future studies should further expand the SDC through empirical estimation within the context of the landscape to gain a better scientific understanding of regulated river ecology.

Author Keywords: benthic invertebrates, dams, longitudinal, recovery, River Continuum Concept, Serial Discontinuity Concept