Graduate Theses & Dissertations

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Using environmental DNA (eDNA) metabarcoding to assess aquatic plant communities
Environmental DNA (eDNA) metabarcoding targets sequences with interspecific variation that can be amplified using universal primers allowing simultaneous detection of multiple species from environmental samples. I developed novel primers for three barcodes commonly used to identify plant species, and compared amplification success for aquatic plant DNA against pre-existing primers. Control eDNA samples of 45 plant species showed that species-level identification was highest for novel matK and preexisting ITS2 primers (42% each); remaining primers each identified between 24% and 33% of species. Novel matK, rbcL, and pre-existing ITS2 primers combined identified 88% of aquatic species. The novel matK primers identified the largest number of species from eDNA collected from the Black River, Ontario; 21 aquatic plant species were identified using all primers. This study showed that eDNA metabarcoding allows for simultaneous detection of aquatic plants including invasive species and species-at-risk, thereby providing a biodiversity assessment tool with a variety of applications. Author Keywords: aquatic plants, biodiversity, bioinformatics, environmental DNA (eDNA), high-throughput sequencing, metabarcoding
Using genomic and phenotypic data to explore the evolution and ecology of the North American mountain goat
Evaluating the impact of climate change is arguably one of the main goals of conservation biology, which can be addressed in part by studying the demographic history of species in the region of interest. In North America, landscape and species composition during the most recent Pleistocene epoch was primarily influenced by glaciation cycles. Glacial advance and retreat caused species ranges to shift as well, leaving signatures of past population bottlenecks in the genetic code of most species. Genomic tools have shown to be important tools for understanding these demographic events to enhance conservation biology measures in several species. In my thesis I first reviewed the state of ungulate genomics, with a focus on how such data sets can be used in understand demography, adaptation, and inform conservation and management. Importantly, the review introduces key analyses like the pairwise sequentially Markovian coalescent and features like variation in antlers and horns and selection pressures that are used throughout subsequent chapters. Using the North American mountain goat as a model species, I then explored the genomic and phenotypic variation in this alpine specialist mammal. Starting with the generation of the first genome assembly for the mountain goat, I identified genes unique to the mountain goat and modeled demographic history going back millions of years using a pairwise sequentially Markovian coalescent approach. Species’ effective population size generally paralleled climatic trends over the past one hundred thousand years and severely declined to under a thousand individuals during the last glacial maximum. Given the biological importance of horns in mountain goats and the recent scientific interest in genetic basis of headgear, I analyzed over 23,000 horn records from goats harvested in British Columbia, Alaska and Northwest Territories from 1980 to 2017. Overall, variation in horn size over space and time was low; goats harvested further North had shorter horn lengths and smaller horn circumferences in one year old and 4 years and older age classes and 4 years and older age class, respectively. Proximity of roads, which was used as an indicator of artificial selection, had a small effect on horn size, with larger horns being harvested closer to major roads. Finally, I used two range-wide genomic data sets sequenced with a whole genome re-sequencing and reduced representation approaches to provide estimates of genetic diversity, contemporary effective population sizes and population structure. These insights can help inform management and will potentially make an impact in preserving the mountain goat. Author Keywords: genome assembly, horn size, Oreamnos americanus, population demography, reduced representation sequencing, whole genome resequencing
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
Using ultra high-resolution mass spectrometry to characterize the biosorbent Euglena gracilis and its application to dysprosium biosorption
Euglena gracilis is an enigmatic and adaptable organism that has great bioremediationpotential and is best known for its metabolic flexibility. The research done in this dissertation addresses (1) how growth conditions impact cellular composition, and (2) how chemometric approaches (such as statistical design of experiments and artificial neural networks) are viable alternatives to the conventional biosorption models for process optimization. Using high-resolution mass spectrometry for biosorbent characterization is a powerful way to assess the chemical characteristics of lyophilized and fractionated cells with high precision, especially to screen for compound classes that may have potentiality for rare earth element removal. Growth conditions impacted cellular composition and separated size fractions of cells yielded different molecular/chemical properties as described by compositional abundances, thus different biosorptive potential. Untargeted analysis demonstrated that exponential dark-grown cells with glucose supplementation were abundant in polyphenolic- and carbohydrate-like compounds, molecular species highly involved in rare earth element binding. Light grown cells had more heterogeneity and the highest molecular weighted fractions from light grown cells (fraction D) had the most abundances of polyphenolic- and protein-like structures. Chemometric modeling used identified the best and worst conditions for iii dysprosium sorption and showed that pH had the most significant influence on bioremoval. Bioremoval ranged from 37% at pH 8 to 91% at pH 3 at Dy concentration ranging from 1 to 100 μg L-1. The work presented in the PhD dissertation will aid in understanding the chemical characteristics of biosorbents by using a Van krevelen analysis of elemental ratios whether algal cells are grown in different environmental growth conditions, or when algal cell are size fractionated. This is especially applied for the screening for metal binding potentiality to Dysprosium. Chemometric methods provide an alternative method for the investigating factors for bioremoval, and applications for process optimization and for real-world applications. This dissertation will aid in understanding chemical characteristics when a biosorbent is grown in a given condition and which factors are important for rare earth element (REE) bioremoval. The significance of this work aims to look for alternate ways to screen biosorbents and using a more efficient experimental design for REE bioremoval. Author Keywords: bioremoval, biosorption, chemometrics, dysprosium, euglena, mass spectrometry
Utilizing Class-Specific Thresholds Discovered by Outlier Detection
We investigated if the performance of selected supervised machine-learning techniques could be improved by combining univariate outlier-detection techniques and machine-learning methods. We developed a framework to discover class-specific thresholds in class probability estimates using univariate outlier detection and proposed two novel techniques to utilize these class-specific thresholds. These proposed techniques were applied to various data sets and the results were evaluated. Our experimental results suggest that some of our techniques may improve recall in the base learner. Additional results suggest that one technique may produce higher accuracy and precision than AdaBoost.M1, while another may produce higher recall. Finally, our results suggest that we can achieve higher accuracy, precision, or recall when AdaBoost.M1 fails to produce higher metric values than the base learner. Author Keywords: AdaBoost, Boosting, Classification, Class-Specific Thresholds, Machine Learning, Outliers
VISUAL INFORMATION-PROCESSING AND THE EVOLUTION OF FLAKE MAKING SKILL
Flaked stones tools are the oldest and longest persisting human cultural remains. Some of these tools were made by hominins who were not anatomically or cognitively modern. My thesis uses an eye-tracking device, developed by psychology, to study modern day novice and expert tool making. By comparing these two groups I was able to characterize the behaviours that lead to successful flake making, and furthermore make inferences about the cognitive capacities that hominins would have had to have to have been successful themselves. This study suggests limited engagement of short-term memory and problem solving skills, which is consistent with other studies. However, this study seems to refute the hypothesis that improvements in hand-eye coordination alone account for the rise of flaked stone technology. My thesis also shows that eye-tracking is a fruitful way to study flake making and, based on my research, I propose several future directions of study. Author Keywords: Eye-tracking, Human Evolution, Knapping, Oldowan, Skill
Variation in the δ15N and δ13C composition of POM in the Lake Simcoe watershed
The purpose of this study was to quantify the variation of baseline carbon and nitrogen stable isotope signatures in the Lake Simcoe watershed and relate that variation to various physicochemical parameters. Particulate organic matter samples from 2009 and 2011 were used as representatives of baseline isotopic values. Temporal data from two offshore lake stations revealed that δ15N of POM was lowest mid-summer and highest after the fall turnover. POM δ13C was variable throughout the summer before declining after fall turnover. Spatial data from the lake and the tributaries revealed that POM stable isotope signatures were highly variable. Various physicochemical parameters indicative of phytoplankton biomass were significantly positively correlated with POM δ15N and significantly negatively correlated with POM δ13C. The correlations were mostly significant in the tributaries, not the lake. Moreover, many of the correlations involving δ15N of POM were driven by extreme values in Cook's Bay and its tributaries. In general, it's likely that different processes or combination of processes were affecting the δ15N and δ13C POM in the Lake Simcoe watershed as physicochemical parameters alone could not explain the variability. Measuring the δ15N of ammonium and nitrate, as well as the δ13C of DIC would help discern the dominant nitrogen and inorganic carbon cycling processes occurring in the Lake Simcoe watershed. Author Keywords: δ13C, δ15N, isotopic baseline, particulate organic matter, spatial variation, stable isotopes
Virtual Voices
A consistent provincial approach to capacity planning for rehabilitative care had been identified as a critical gap in the field of health care in Ontario (Rehabilitative Care Alliance, 2015a). In response, the rehabilitative care alliance (RCA) developed a needs based hip fracture capacity planning canvas together with persons and families. This research utilized computer assisted participation (CAP) to gather additional perspectives from Virtual Voices via an on-line survey. The results of the Virtual Voices survey were compared to Ontario’s RCA hip fracture patient focus group findings. CAP facilitated more voices and more ideas through virtual engagement. The survey method required 97% (10.6 hours) less time than the focus group. The Virtual Voices respondents provided validation of the focus groups’ confirmation of the rehabilitative care needs, locations and most core team members as well as identified new ideas. The results support the implementation of a needs-based capacity plan that enables individualized care planning. This research provides a blueprint for the ongoing engagement of persons and families in the co-creation of a sustainable rehabilitative care system. A dashboard and e-health app would enable ongoing co-design, monitoring and evaluation. Author Keywords: Computer Assisted Participation (CAP), Computer Assisted Survey, Hip Fracture, Rehabilitative Care Needs, Virtual Collaboration, Virtual Engagement
Visions of the Sedantary “I”/eye
This thesis explores the seemingly innocuous call to “grow up,” which is never simply a biological imperative. It is also a moral one. Demanding that one should “grow up” is not demanding that one grow older, but that one transform into a specific kind of subject – the “grown up.” In the reading advanced here, The Little Prince thermalizes the suppleness of the figure of the grown up through a series of fantastic encounters. In particular, perception and corporeality will be taken up as the two interlocking ways we are often pushed towards an understanding of adulthood that is coextensive with an Enlightenment conception of subjectivity. Perception, having emerged from a sedimented economy of looking, produces norms and practices of attentiveness where much of our perceptual field is consigned to infrastructural obliviousness. This intensification of attention, in turn, coincides with a broader project of corporeal discipline that began with the body’s sedation through the chair. The chair is itself an element of the disciplinary machine that regulates attention, where the pedagogical injunction to “pay attention” is often accompanied by the postural injunction to “settle down” and “sit up straight.” The chair, then, not only individuates and renders those individuated bodies docile, but also readies them for an entry into the world of grown-ups. Author Keywords: Attention, Enlightenment, Maturation, Saint-Exupery, Sedantariness, Subjectivation
Volunteer Experiences of Place-making for Sustainable Community Development
This thesis explores the experiences of volunteers who came together to redevelop an abandoned convent into The Mount Community Centre (The Mount) for the purpose of sustainable community development. The goal of the research was to explore the relational processes of place-making at The Mount, to be achieved through two objectives: first, to describe the nature of collaboration among volunteers in place at The Mount; and second, to understand the experience of volunteers through their narratives and descriptions, with respect to the influence of The Mount as a place. Methods employed were participant observation and key-informant interviews with 24 participants conducted using a video-documentary approach. The result was a community-based, qualitative case study comprised of volunteer voices, in their collective narrative of experience of The Mount’s development trajectory. A thematic analysis of volunteer narratives indicated patterns of connectivity and the expansion of relational networks of place, implicated in strategic approaches in three experiential phases of Daring, Erring, and Groundswell along the development’s trajectory. In demonstrating how place influences community organization to address needs, The Mount provides an example for future inquiry that contributes to the advancement of knowledge in discussions of voluntarism, place, and sustainable community development. Keywords: Voluntarism, place-making, sustainable community development, community-based research Author Keywords: community-based research, Non-profit sector, Place, Place-making, Sustainable-community development, Voluntarism
Vulnerability and resilience
The Minority Stress Model proposes that LGBTQ+ people experience stressors unique to their identity that negatively impact their mental well-being. The model also outlines that, in the case of the LGBTQ+ community, two minority coping resources - social support and connection to the LGBTQ+ community – may act as potential minority stress buffers; however, research has been unable to determine if these are effective buffers. The current study used multiple regression and multilevel modelling to test the processes of the Minority Stress Model among 451 LGBTQ+ people over 25 timepoints during the COVID-19 pandemic. Although minority stressors and coping resources were associated with psychological distress in the expected directions, an interesting interaction between the two measures of minority stress was revealed and neither minority coping resource was found to buffer the association between minority stress and distress. In conclusion, the present study found partial support for the Minority Stress Model using longitudinal data but highlights the complex nature of these processes and how they are conceptualised in research. Author Keywords: identity concealment, LGBTQ+ community, mental health, minority coping, minority stress model, social support
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

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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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1973 - 2033
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Format: 2023/05/28

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