Graduate Theses & Dissertations

Pages

Influence of Nitrogen Deposition on Community Composition in Pinus banksiana Forests Across Northwestern Canada
Anthropogenic atmospheric emissions and subsequent deposition of nitrogen (N) can affect N-sensitive habitats and lead to shifts in plant species community composition. This study assessed the effects of N deposition on plant community composition for Jack pine forests across northwestern Canada and across a smaller subset of sites surrounding the Athabasca Oil Sands Region (AOSR) using ‘gradient forest’ analysis. Predictor influence on community composition varied depending on the scale of the study and relatively distinct thresholds were identified for different plant groups. In the larger scale study, a total deposited nitrogen (TDN) threshold of 1.5 – 3 kg N ha-1yr-1 was well suited to protect predominantly lichen species, consistent with lichen-based critical loads from other studies. Across the smaller scale study, a TDN threshold of 5.6 kg N ha-1yr-1 was primarily associated with vascular species changepoints but did include some important N-indicator lichen and bryophyte species. Author Keywords: critical loads, gradientForest, Jack pine, Nitrogen deposition, species composition
It's All in Your Head
The Continuity Hypothesis states that dreams reflect waking day cognition and experiences, which reflect one’s mental health status. As such, dreams are, by extension, cognitions that occur during sleep. To date, Cognitive Behavioural Therapy (CBT) is deemed the most efficacious method of social anxiety treatment by working with cognitions. The current study utilized both CBT and The Storytelling Method (TSM) of dream interpretation, whose methodology is based on CBT; CBT works with waking cognitions and TSM works with sleep cognition. This study examined the effectiveness in decreasing social anxiety symptoms with TSM and comparing its efficacy to a traditional CBT technique. Undergraduate psychology students (N = 36) completed a daily journal of either the TSM or CBT format for two weeks. Participants completed self-report measures of social anxiety, state-anxiety, and depression before and after practicing either method. TSM did not significantly decrease levels of social anxiety, state-anxiety, or depression, whereas CBT significantly decreased only social anxiety levels. Dream content reflecting waking day anxiety and depression did not decrease over time, coinciding with the findings that students did not experience a decrease in their waking day life, supporting the Continuity Hypothesis. Findings suggest anxiety and depression to be very stable in this sample. Future research should explore interventions that are clinician-guided, in a group setting, or, occur over a longer period of time. Author Keywords: Content Analysis, Social anxiety, The Storytelling Method
Syrphidae (Diptera) of northern Ontario and Akimiski Island, Nunavut
Syrphids, also known as hover flies (Diptera: Syrphidae) are a diverse and widespread family of flies. Here, I report on their distributions from a previously understudied region, the far north of Ontario, as well as Akimiski Island, Nunavut. I used samples collected through a variety of projects to update known range and provincial records for over a hundred species, bringing into clearer focus the distribution of syrphids throughout this region. I also analysed a previously un-tested trap type for collecting syrphids (Nzi trap), and report on results of DNA analysis for a handful of individuals, which yielded a potential new species. Author Keywords: Diptera, Ontario, range extension, Syrphidae
Expression of Giardia intestinalis flavoenzyme GiOR-1 and characterization of its electron transfer properties
Giardia intestinalis possesses four isotypes of cytochrome b5 (gCYTB-I-IV) that differ from their mammalian counterparts, suggesting different functions in this protozoan parasite. Although the recently discovered Giardia flavoenzyme, GiOR-1, reduces these cytochromes, its properties have not been thoroughly studied, owing to the difficulty in its expression. Here I describe successful conditions for expression of GiOR-1 using autoinduction. GiOR-1 is obtained with flavins bound as indicated by its UV-visible spectrum. Its ability to catalyze electron transfer from donors (NADH, NADPH) to acceptors (oxygen, ferricyanide, cytochrome c, gCYTB5-III) were studied in spectrophotometric rate assays. NADPH is the preferred electron donor, while cytochromes are the preferred electron acceptors. Interestingly, the His-tag used to purify gCYTB5-III decreases its reaction rate with GiOR-1, as an untagged version has slightly faster rates. These findings establish the appropriate conditions for further studies on GiOR-1, including the identification of endogenous electron acceptors. Author Keywords: Autoinduction, Cytochrome b5, Cytochrome P450 oxidoreductase, Giardia intestinalis, GiOR-1, Polyhistidine tag
Responses of Primary Producers and Grazers to Silver Nanoparticle Exposure
The increasing production and use of silver nanoparticles (AgNPs) raise concerns on environmental exposure and impact. A large scale in situ enclosure study was conducted at the Experimental Lakes Area to determine the effect of AgNPs on natural phytoplankton and zooplankton communities. This study investigated AgNPs of varying concentrations (4, 16 and 64 μg/L), dosing regimens (chronic vs. pulse), and capping agents (poly-vinyl pyrrolidone vs. citrate). Phytoplankton communities were influenced only by the natural limnological properties of the system signifying tolerance to AgNPs. Zooplankton community structure significantly changed with AgNP concentration and dosing regimen indicating AgNP sensitivity. A microcosm study investigating the effect of AgNPs and phosphorus-dosed periphyton before and after grazing by two benthic invertebrate species (snails and caddisfly larvae) showed reduced periphyton stoichiometry with AgNP exposure. Grazers foraged less on silver dosed periphyton indicating a preferential choice in food quality. Phosphorus reduced the detrimental effects of AgNPs across all conditions. These studies verify the need for in situ experimental designs to fully investigate the effects of AgNPs and their interaction with environmental factors, multiple species assemblages, and across trophic levels. Author Keywords: benthic invertebrate, Experimental Lakes Area, periphyton, phytoplankton, silver nanoparticles, zooplankton
History and Legacy of the “Orillia Asylum for Idiots
The “Orillia Asylum for Idiots” (1861 - 2009), Canada’s oldest and largest facility for the care and protection of children and adults with disabilities, was once praised as a beacon of humanitarian progress and described as a “community within a community.” Yet, survivors who lived in the facility during the post Second World War period, a time described as the “golden age of children’s rights,” tell harrowing stories of abuse and neglect. Despite the nation’s promise to “put children first” and protect the universal rights of “Canada’s children,” children incarcerated within the Orillia Asylum were subjected to systemic neglect and cultural discrimination, daily humiliation and dehumanization, and physical, sexual, and emotional abuse. Far from being a place for child protection and care, this dissertation finds that the Orillia Asylum was a site of a multi-faceted and all-encompassing violence, a reality that stands in complete contrast to the grand narrative through which the facility has historically been understood. This dissertation considers how such violence against children could occur for so long in a facility maintained by the state, a state invested in protecting children. It finds that children who were admitted to the Orillia Asylum were not considered to be “Canada’s children” at all by virtue of being labelled as “mentally deficient,” “feeble-minded,” “not-quite-human,” and “not-quite-children.” Author Keywords: childhood, disability, Huronia Regional Centre, institutional child abuse, institutional violence, institutionalization
Using the Same Language, but Meaning Different Things
Two dominant narratives emerging throughout the war were the national narrative––that is, the narrative of the war as articulated by the British nation via texts such as political speeches, recruitment posters, and popular music–– and the poetic narrative––that is, the narrative of the war emerging from poets, specifically battlefront poets for the sake of this thesis. One hundred years since World War One, these two narratives are often conceptualized as mutually exclusive, even antithetical to one another. This thesis brings these diverse narratives into conversation with one another by investigating how they both draw on the same rhetorics and yet use these rhetorics to differing ends. Interestingly, the rhetorics employed by both narratives throughout the war endure in contemporary remembrance practices in Britain today. By investigating how each narrative draws on and employs the same rhetorics, this thesis both contextualizes and complexifies contemporary interpretations of contemporary remembrance practices. Author Keywords: Battlefront Poetry , Britain, Narrative, Remembrance, Rhetoric, World War One
Diversity, Biogeography, and Functional Traits of Native Bees from Ontario’s Far North and Akimiski Island, Nunavut
Bees (clade Anthophila), are poorly studied in northern Canada, as these regions can be difficult to access and have a short growing season. This study examined bees from two such regions: Ontario’s Far North, and Akimiski Island, Nunavut. I present this study as the largest biogeographical study of bees performed in these remote areas to enhance knowledge of northern native bees. I found 10 geographically unexpected species in Ontario and on Akimiski Island. Rarefaction and the Chao 1 Diversity Index showed that Akimiski is nearly as diverse as the Far North of Ontario, a significantly larger area. I also found, based on log femur length versus latitude, Bombus worker size was consistent with Bergmann’s rule, and there were no apparent statistical differences in the community weighted means of functional traits between the Far North’s Boreal Shield and Hudson Bay Lowlands ecozones. This work provides invaluable knowledge of the native bee species from these regions, which has implications for their future conservation. Author Keywords: Akimiski Island, Bergmann's rule, Chao 1, Community-weighted means, native bees, rarefaction
WOMEN IN HORROR
The objective of this dissertation is to measure the influence of the contemporary influx of women’s involvement in the horror genre in three dimensional capacities: female representation in horror films, female representation as active, participatory spectators and female representation in the industrial production of horror. Through the combined approach of theoretical and empirical analysis, this dissertation examines the social conditions that facilitated women’s infiltration of the horror genre. Beginning with psychoanalytic theories of spectatorship, it is demonstrated that female filmmakers have challenged horror’s traditional images of victimized women through the development new forms of feminine representation in contemporary horror films. Using data collected from a sample of 52 self-identified female horror fans, it is revealed that the purported invisibility of female horror spectators is a consequence of their alternative modes of consumption. Through interviews conducted with four female producers and an examination of their cultural productions, I illustrate that women have reconstituted the horror genre as a space for inclusivity, political activism and feminist empowerment. Cohesively, these findings reveal the contemporary feminist reclamation of horror to be a form of resistance intended to challenge the patriarchal structures that facilitated women’s historical exclusion from the horror genre. Author Keywords: Abjection, Feminism, Film, Gender, Horror, Psychoanalysis
Re-Living the Residential School Experience
The residential school legacy is one of the darkest chapters in Canadian history. From the mid-1850s to 1996, thousands of Aboriginal children were taken from their homelands and placed in residential schools. Taken against their will, many dreaded attending these schools. Some attended for as long as ten to fifteen years, only to be strangers in their own communities upon their return. In the past thirty years, survivors began disclosing the loneliness, confusion, fear, punishment and humiliation they suffered within these institutions, and also reported traumatic incidents of sexual, physical or emotional abuse. These childhood traumas still haunt them today. This dissertation examines the four compensation processes (Litigation, Alternative Dispute Resolution, Independent Assessment Process and the Common Experience Process) used by survivors to determine whether the compensation payments made to them assisted in reconciliation of their residential school experience. To complete an analysis of the processes, twenty-four residential school survivors from Ontario, Manitoba and British Columbia were interviewed about their experiences with one or more of the compensation processes. The study begins with a historical overview of the residential school legacy and continues with the residential school healing movement that initiated and finalized a negotiated settlement agreement for all living survivors. This dissertation provides a unique perspective to the residential school legacy by using a cultural framework, Anishinabe teachings and concepts to share the voices of residential school survivors. The pivotal Anishinabe teaching within this study comes from The Seventh Fire Prophecy. This prophecy states that: “If the New People will remain strong in their quest, the Waterdrum of the Midewiwin Lodge will again sound its voice.” In this dissertation the residential school survivors are the New People. As the dissertation unfolds the author utilizes various Anishinabe concepts to illustrate how the compensation processes failed to assist the New People to reconcile with their residential school experience. This study presents a medicine wheel understanding of reconciliation and the Residential School Legacy. It concludes with an important message to the second and third generation survivors to continue the reconciliatory efforts that the New People introduced. It is crucial that the children and grandchildren of the New People begin the reconciliation process not only for themselves but for the next seven generations. Author Keywords: Anishinabe, compensation, Indian residential schools, reconciliation, survivors
Nutrient Metabolism of an Aquatic Invertebrate and its Importance to Ecology
Aquatic consumers frequently face nutritional limitation, caused in part, by imbalances between the nutrients supplied by primary producers and the metabolic demands of the consumers. These nutritional imbalances alter many ecological processes including consumer life-history traits, population dynamics, and food web properties. Given the important ecological role of organismal nutrition, there is a need to have precise and specific indicators of nutritional stress in animals. Despite this need, current methods used to study nutrition are unable to distinguish between different types of nutritional limitation. Here I studied nutritional metabolism in the freshwater zooplankter, Daphnia. A greater understanding of nutritional metabolism would allow for the development of dietary bio-indicators that could improve the study of the nutritional ecology of animal consumers. Specifically, I addressed the question: What affects the biochemical composition of a generalist aquatic consumer? My overall hypothesis was that the quantity and quality of the diet affects the biochemical composition in a nutrient specific manner. To test this hypothesis, I examined various response variables involved in nutrient metabolism such as alkaline phosphatase activity, whole metabolome, and free amino acid composition. For each response variable, I grew Daphnia under various nutritional stressors and determined if responses are nutrient specific or are a general stress response. I found the current method of measuring alkaline phosphatase was not a phosphorus specific indicator, as activity increased in all nutrient stressed treatments. Analyzing the whole metabolome resulted in nutritional stressors being separated in multivariate space, with many identified metabolites being significantly different from nutrient rich Daphnia. Upon further examination the daphnids free amino acids profiles are caused by differences between the supply of amino acids from the algae and the demand within the Daphnia. These differences in supply and demand resulted in the ability to classify the nutritional status of Daphnia with the use of discriminant analysis, a classification multivariate model. In addition to a deeper understanding and advanced knowledge of the physiological changes caused by nutrient limitation, this research has provided strong evidence for the application of nutritional biomarkers/profiles to identified the nutritional status of Daphnia. Author Keywords: Bio-indictor, Ecological stoichiometry, Metabolism, Nutritional limitation, Nutritional status
Evaulating the American Woodcock Singing-Ground Survey Protocol in Ontario using Acoustic Monitoring Devices
The breeding phenology of American Woodcocks (Scolopax minor) was evaluated in Ontario, Canada to determine if changes in dates of courtship activity have introduced negative bias into the American Woodcock Singing-ground Survey (SGS). Long-term woodcock phenology and climate data for Ontario were analysed using linear regression to determine if woodcock breeding phenology has changed between 1968 and 2014. There was no significant trend in woodcock arrival date, but arrival date was correlated with mean high temperature in March. In 2011-2013, programmable audio-recording devices (song meters) were deployed at known woodcock singing-grounds to determine if peaks in courtship activity coincided with survey dates used by the SGS. Spectrogram interpretation of recordings and data analyses using mixed-effects models indicated the SGS survey dates were still appropriate, except during the exceptionally early spring in 2012 when courtship displays were waning in one region during the survey window. The methods for interpretation of song meter recordings were validated by conducting point counts adjacent to song meters deployed at singing-grounds, and at randomly selected locations in woodcock habitat. Recommendations for the SGS protocol are included. Author Keywords: detectability, phenology, Scolopax minor, Singing-ground Survey, song meter

Pages

Description

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

In collections

Search Our Digital Collections

Query

Enabled Filters

  • (-) ≠ Morrison
  • (-) ≠ Art criticism

Filter Results

Date

1973 - 2033
(decades)
Specify date range: Show
Format: 2023/09/25

Collection

Author Name

Show more

Name (Any)

Show more

Degree

Degree Discipline

Show more

Subject (Topic)

Show more