Graduate Theses & Dissertations

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Population cycles are regular fluctuations in population densities, however, in recent years many cycles have begun to disappear. With Canada lynx this dampening has also been seen with decreasing latitude corresponding to an increase in prey diversity. My study investigates the role of alternate prey on the stability of the lynx-hare cycle by first comparing the functional responses of two sympatric but ecologically distinct predators on a primary and alternate prey. I then populated a three species predator-prey model to investigate the role of alternate prey on population stability. My results showed that alternate prey can promote stability, though they are unlikely to “stop the cycle”. Furthermore, stability offered by alternate prey is contingent on its ability to increase intraspecific competition. My study highlights that population cycles are not governed by a single factor and that future research needs to be cognizant of interactions between alternate prey and intraspecific competition. Author Keywords: alternate prey, Canis latrans, functional response, Lepus americanus, Lynx canadensis, Tamiasciurus hudsonicus
Reconceptualizing Immigration in Canada
This thesis challenges the contemporary framework of immigration in Canada. Despite Canada’s effort to promote cultural diversity and multicultural citizenship, immigration policy in the last decade has moved towards a model of cultural assimilation. The recent Bill—Strengthening Canadian Citizenship Act—devalues non-European cultures and hinders the successful integration for new immigrants. The problem of contemporary immigration in Canada lies in the narrow and exclusive understanding of immigration. That is, the current immigration framework is rooted in Eurocentrism, which draws exclusively from the economic and cultural values of the West. The Eurocentric understanding of migration not only hinders the successful integration for new immigrants, but it also hinders economic growth and weakens the social cohesion of Canada. For this reason, this thesis offers an alternative framework for understanding immigration. I focus on Chinese migration in Canada and take an interdisciplinary and a conceptual approach in order to present an inclusive understanding of Chinese migration. In particular, I apply the idea of "connected histories" to the context of immigration, and I demonstrate that immigration is a complex and interconnected phenomenon which cannot be reduced to the narratives of economics and ‘Canadian values.’ Instead, immigration should be understood as a process of transnational interactions because it not only allows us to understand benefits that transnational interactions would bring to immigrants, their country of origin and Canada, but it also recognizes different values and the agency of immigrants. Author Keywords: Bill C-24, Chinese Canadians, Eurocentrism, Immigration, Multicultrualism, Transnational
Assessing factors associated with wealth and health of Ontario workers after permanent work injury
I drew on Bourdieu’s theory of capital and theorized that different forms of economic, cultural and social capital which injured workers possessed and/or acquire over their disability trajectory may affect certain outcomes of permanent impairments. Using data from a cross-sectional survey of 494 Ontario workers with permanent impairments, I measured workers’ different indicators of capital in temporal order. Hierarchical regression analyses were used to test the unique association of workers’ individual characteristics, pre-injury capital, post-injury capital, and the outcomes of permanent impairments. The results show that factors related to individual characteristics, pre-injury and post-injury capital were associated with workers’ perceived health change, whereas pre-injury and post-injury capital were most relevant factors in explaining workers’ post-injury employment status and income recovery. When looking at the significance of individual predictors, post-injury variables were most relevant in understanding the outcomes of permanent impairment. The findings suggest that many workers faced economic and health disadvantages after permanent work injury. Author Keywords: Bourdieu, hierarchical regression, theory of capital, work-related disability, workers with permanent impairments
effects of Dissolved Organic Matter (DOM) sources on Pb2+, Zn2+ and Cd2+ binding
Metal binding to dissolved organic matter (DOM) determines metal speciation and strongly influences potential toxicity. The understanding of this process, however, is challenged by DOM source variation, which is not always considered by most existing metal speciation models. Source determines the molecular structure of DOM, including metal binding functional groups. This study has experimentally showed that the allochthonous-dominant DOM (i.e. more aromatic and humic) consistently has higher level of Pb binding than the autochthonous-dominant DOM (i.e. more aliphatic and proteinaceous) by more than two orders of magnitude. This source-discrimination, however, is less noticeable for Zn and Cd, although variation still exceeds a factor of four for both metals. The results indicate that metal binding is source-dependent, but the dependency is metal-specific. Accordingly, metal speciation models, such as the Windermere Humic Aqueous Model (WHAM), needs to consider DOM source variations. The WHAM input of active fraction of DOM participating in metal binding (f) is sensitive to DOM source. The commonly-used f = 0.65 substantially overestimated the Pb and Zn binding to autochthonous-dominant DOM, indicating f needs to be adjusted specifically. The optimal f value (fopt) linearly correlates with optical indexes, showing a potential to estimate fopt using simple absorbance and/or fluorescence measurements. Other DOM properties not optically-characterized may be also important to determine fopt, such as thiol, which shows strong affinity to most toxic metals and whose concentrations are appreciably high in natural waters (< 0.1 to 400 nmol L-1). Other analytical techniques rather than Cathodic Stripping Voltammetry (CSV) are required to accurately quantify thiol concentration for DOM with concentration > 1 mg L-1. To better explain the DOM-source effects, the conditional affinity spectrum (CAS) was calculated using a Fully Optimized ContinUous Spectrum (FOCUS) method. This method not only provides satisfactory goodness-of-fit, but also unique CAS solution. The allochthonous-dominant DOM consistently shows higher Pb affinity than autochthonous-dominant DOM. This source-discrimination is not clearly observed for Zn and Cd. Neither the variability of affinity nor capacity can be fully explained by the variability of individual DOM properties, indicating multiple properties may involve simultaneously. Together, the results help improve WHAM prediction of metal speciation, and consequently, benefit geochemical modelling of metal speciation, such as Biotic Ligand Model for predicting metal toxicity. Author Keywords: Dissolved organic matter, Metal binding, Source, Windermere Humic Aqueous Model
Characterization of a Zn(II)2Cys6 transcription factor in Ustilago maydis and its role in pathogenesis
Ustilago maydis (D.C.) Corda is a biotrophic pathogen that secretes effectors to establish and maintain a relationship with its host, Zea mays. In this pathosystem, the molecular function of effectors is well-studied, but the regulation of effector gene expression remains largely unknown. This study characterized Zfp1, a putative U. maydis Zn(II)2Cys6 transcription factor, as a modulator of effector gene expression. The amino acid sequence of Zfp1 indicated the presence of a GAL4-like zinc binuclear cluster as well as a fungal specific transcription factor domain. Nuclear localization was confirmed by tagging Zfp1 with enhanced green fluorescent protein. Deletion of zfp1 resulted in attenuated hyphal growth, reduced infection frequency, an arrest in pathogenic development, and decreased anthocyanin production. This phenotype can be attributed to the altered transcript levels of genes encoding predicted and confirmed U. maydis effectors in the zfp1 deletion strain during pathogenic growth. Complementation of zfp1 deletion strain with tin2, an effector involved in anthocyanin induction, suggested this effector is downstream of Zfp1 and its expression is influenced by this transcription factor during in planta growth. When wild-type zfp1 was ectopically inserted in the zfp1 deletion strain, pathogenesis and virulence were partially restored. This, coupled with zfp1 over-expression strains having a similar phenotype as the deletion strains, suggested Zfp1 may interact with other proteins for full function. These findings show that Zfp1, in conjunction with one or more binding partners, contributes to U. maydis pathogenesis, virulence, and anthocyanin production through the regulation of effector gene expression. Author Keywords: effector, pathogenesis, transcription factor, Ustilago maydis, Zea mays, zinc finger
All I've Found is Pain and Terror
This thesis is concerned with how specific aesthetic elements function in various contemporary texts to distort, obscure, or illuminate the immoral actions and behaviours being represented. This thesis applies the moral status philosophy of Mary Anne Warren, along with the moral philosophy of Emmanuel Lévinas and Zygmunt Bauman. Close reading and critical analysis are supported by Michele Aaron’s theory of spectatorship. The sublime is explored in Dexter (2006) and Batman: The Dark Knight Returns (1986), the uncanny in Battlestar Galactica (2003) and Westworld (2016), and the abject in The Walking Dead (2003) and World War Z (2006). The intentions of this project are to conduct a formal examination of the relationship between audience and text as it is filtered through aesthetic representation and moral frameworks. This thesis argues that aesthetic effects must be understood in connection to morality for active consumers to engage with these texts as sites for ethical consideration. Author Keywords: aesthetic theory, moral status philosophy, Popular fiction, spectatorship, The Walking Dead, Westworld
Detectability and its role in understanding upland sandpiper (Bartramia longicauda) occurence in the fragmented landscape of southern Ontario
Upland Sandpipers (Bartramia longicauda), like many grassland birds, are undergoing population decline in parts of their range. Habitat fragmentation and change have been hypothesized as potential causes of decline. I used citizen-science occurrence data from Wildlife Preservation Canada’s Adopt-A-Shrike Loggerhead Shrike (Lanius ludovicianus) program in conjunction with validation surveys, using similar point-count methods, to examine detectability and determine if landscape level habitat features could predict occupancy of Upland Sandpipers in Southern Ontario. In a single season detectability study, I used Wildlife Preservation Canada’s survey protocol to determine detectability in sites that were known to be occupied. Detectability was low, with six surveys necessary to ensure detection using a duration of at least 18 minutes early in the breeding season. The proportion of open habitat did not affect detection on the landscape. Using a larger spatial and temporal scale, with five years of citizen-science data, I showed that Annual Crop Inventory data could not effectively predict Upland Sandpiper occupancy. Model uncertainty could be attributed to survey protocol and life history traits of the Upland Sandpiper, suggesting that appropriate survey methods be derived a priori for maximizing the potential of citizen-science data for robust analyses. Author Keywords: Bartramia longicauda, citizen-science, detection, landscape, occupancy, Ontario
Emerging Dynamic Social Learning Theory of a Learning Community of Practice
In current knowledge-based economy, knowledge might be viewed as the most valuable organizational resource in sustaining any organization. Organizational knowledge originates from cognitive learning by individuals situated within organizations. In organizational learning, situated learning of knowledge by individuals is shared to create sustainable organizational competency. Yet, there is inadequate research to understand how situated learning operates as a social learning system within Community of Practice (‘CoP’). Through a case study of a multi-level, non-profit CoP in Ontario, Canada, this qualitative explanatory research contributes to the extant literature by building a unique theoretical framework that provides conceptual insights on linkages between organizational knowledge, social learning system, and organizational competency, in sustaining the organizational CoP. Using Straussian grounded theory methodology, qualitative primary data from in-depth interviews, participant observations, and documents were triangulated and analysed abductively to reveal an emerging dynamic knowledge-based social learning theory towards explaining how situated learning sustains this learning CoP. Author Keywords: Community of Practice, Grounded Theory, Organizational Knowledge, Organizational Learning, Organizational Sustainability, Situated Learning
Comparative phylogeography in conservation biology
Phylogeographic histories of taxa around the Great Lakes region in North America are relevant to a range of ongoing issues including conservation management and biological invasions. In this thesis I investigated the comparative phylogeographic histories of plant species with disjunct distributions and plant species with continuous distributions around the Great Lakes region; this is a very dynamic geographic area with relatively recent colonisation histories that have been influenced by a range of factors including postglacial landscape modifications, and more recently, human-mediated dispersion. I first characterized four species that have disjunct populations in the Great Lakes region: (Bartonia paniculata subsp. paniculata, Empetrum nigrum, Sporobolus heterolepis, and Carex richardsonii). Through comparisons of core and disjunct populations, I found that a range of historical processes have resulted in two broad scenarios: in the first scenario, genetically distinct disjunct and core populations diverged prior to the last glacial cycle, and in the second scenario more recent vicariant events have resulted in genetically similar core and disjunct populations. The former scenario has important implications for conservation management. I then characterized the Typha species complex (T. latifolia, T. angustifolia, T. x glauca), which collectively represent species with continuous distributions. Recent microevolutionary processes, including hybridization, introgression, and intercontinental dispersal, obscure the phylogeographic patterns and complicate the evolutionary history of Typha spp. around the Great Lakes region, and have resulted in the growing dominance of non-native lineages. A broader geographical comparison of Typha spp. lineages from around the world identified repeated cryptic dispersal and long-distant movement as important phylogeographic influences. This research has demonstrated that comparisons of regional and global evolutionary histories can provide insight into historical and contemporary processes useful for management decisions in conservation biology and invasive species. Author Keywords: chloroplast DNA, conservation genetics, disjunct populations, invasive species, phylogeography, postglacial recolonisation
On the Cyberflaneur
This thesis is a critical response to Evgeny Morozov’s article proclaiming the death of the cyberflâneur. Suspicious of the superficiality of his argument, I developed a practico-theoretical project to prove that the cyberflâneur is not dead but alive – or, if it were dead, to rescue it from its grave and bring it back to life. In the course of my response to Morozov, I develop a theoretical foundation that allows me to continue thinking about the concept and practice of the cyberflâneur in the context of the Internet. In doing so, I rely on Gilles Deleuze and Felix Guattari’s “Treatise on Nomadology: The War Machine” (2011), in combination with a history of the tradition of wandering. We are living in a postmodern-posthuman era driven by the chaotic and confusing forces that are manifested through the Internet. As such, it is no longer enough to be concerned with opening the space where we live, move and think; we cannot retreat to nature, we can’t escape society. However, I see potential in the Internet. The Internet, as a physical and material network, can be actualized as an apparatus of capture. It operates as a medium for accelerating or limiting speed, or as an apparatus for the control of the transmission of information. I develop the cyberflâneur as an aesthetic figure that reveals the Internet’s potential. If these revelations happen to be transmitted, then everyday life can again become an object of dispute, rather than unmeditated habituation. Author Keywords: Cyberflâneur, Everyday Life, Internet, Nomadology, Research-creation, Wandering
“It's like getting a new car without the manual”
This study explored teacher infusion of Indigenous curriculum content through interviews with ten non-Indigenous teachers of social studies and history. The interviews centered on teacher perceptions of preparedness to implement Ontario’s recent TRC curriculum revisions, which include more about the contributions, histories, cultures, and perspectives of Indigenous peoples. A brief analysis of Ontario’s First Nation, Métis, and Inuit Education Policy Framework is included, alongside critiques of the Eurocentrism at the heart of education systems. The interviews revealed that many of the teachers were committed to Indigenous education and learning more, but they felt unprepared and lacked resources to teach Indigenous curriculum content with confidence. This study highlighted the critical role of settler teachers in Indigenous education and the importance of teachers undertaking settler unsettling in order to be effective and appropriate in Indigenous curriculum delivery. Individual changes must occur alongside educational system decolonization with a particular focus on teacher preparation. Author Keywords: cognitive imperialism, Indigenous Education, Ontario, settler educator, settler unsettling, TRC curriculum
An Analysis of Hafted Biface Variability in the Kawartha Lakes and Trent River Drainage Region
The objective of this thesis is to evaluate the temporal sensitivity of morphological variability in hafted bifaces in the Kawartha Lakes and Trent River drainage region. This provides a base of information that will enable future analyses that address the possible sources of this variability and to test the robustness of existing typological categories of hafted bifaces for relative dating. This base of information is established via the use of a principal component analysis of shape, raw material, and use-life data from a large sample of hafted bifaces in the region, using a new geometric morphometrics method designed to improve the accuracy of shape representation. The results of the analysis indicate that while certain typological categories may represent distinct morphotypes that are temporally sensitive, the majority of typological categories in the sample show high, overlapping morphological variability that cannot be confidently correlated temporally based on shape alone. Author Keywords: Geometric Morphometrics, Morphological Variability, Ontario Archaeology, Principal Component Analysis, Project Point Morphology, Projectile Point Typology

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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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