Trent University
NMR and EPR Studies on Cytochrome b5 Isotypes of Giardia intestinalis
The amitochondrial protozoan, Giardia intestinalis, encodes four members of the cytochrome b5 (CYTB5) family of heme proteins of unknown function. While homology models can predict the likely fold of these proteins, supporting experimental evidence is lacking. The small size of the cytochromes (~16 kDa) makes them attractive targets for structural analysis by Electron Paramagnetic Resonance spectroscopy (EPR) and Nuclear Magnetic Resonance spectroscopy (NMR). EPR measurements are particularly useful in defining the geometry of the coordination environment of the heme iron; such measurements indicated that the planar imidazole rings of the invariant histidine axial ligands are nearly perpendicular to each other, rather than in the coplanar orientation observed within mammalian CYTB5s. This may be due to geometrical constraints imposed by a one-residue shorter spacing between the ligand pair in the Giardia cytochromes b5 (gCYTB5s). Following optimization of sample and instrument conditions for NMR experiments, a comparison of the 1D 1H-NMR spectra of gCYTB5 isotype I to those of three of its heme-pocket mutants (Tyr51→Phe, Tyr61→F, and Cys84→Ala) were used to tentatively assign the heme methyl and vinyl protons. Mutant Tyr61→F had the greatest effect on the wild-type spectrum due to maximum through-space contacts with the heme macrocycle and its proximity to the His63 axial ligand. These experiments are a prelude to further NMR experiments that can lead to solving the complete structures of these proteins.
Author Keywords: cytochrome b5, heme b, mutant protein, paramagnetic iron, resonant spectroscopy, sequence homology
The Agony of Writing Or Ambivalent Reversal In Baudrillard's Stylistic Metamorphoses
Following Baudrillard's conceptual and stylistic shift of the mid-70s, this thesis argues that said shift is accounted for by understanding the ontological quandary Baudrillard found himself in after developing a theoretical agonism impossible to divorce from the practice of writing. By tracing the conceptual metamorphoses of key terms including semiotic ambivalence, symbolic exchange and theoretical writing itself as a total agonistic process, this thesis demonstrates that theory is not reducible to epistemic production but is rather the contentious site of challenge and aesthetic (dis)appearance. Each chapter examines a conceptual tension revealing insoluble, conflicting social forms. These forms reveal the reversibility Baudrillard finds at work in all social phenomena. These culminate in a chapter that tackles Baudrillard's writing itself as a social form that endeavours to embody the agonistic theoretical concept as a process rather than remaining a representation, or commentary on, ambivalent social conflict.
Author Keywords: agonist, ambivalence, Baudrillard, reversibility, style, writing
MSHKIKENH IKWE NIIN (I am Tutle Woman): The Transformative Role of Anishinaabe Women's Knowledge in Graduate Research
This dissertation offers the dibaajimowin (personal story) of my beading project, which I undertook to understand the enactment of Anishinaabe women's knowledge in graduate research. Framed through the concept of a collective self, which is embedded within the Anishinaabe traditions of storytelling and beading, and drawing further from the aesthetics, processes, and teachings of these traditions so that I proceed in a good way, I am able to tell a story that is wholly Anishinaabe. Through the symbolic literacy present within the pieces of beadwork entitled:"Turtle Woman," "Turtle Woman Meets Grandmother Moon," "Turtle Woman Marries a Beaver," and "Turtle Woman Slays the Big Fish," which I present in the second half of this story, I explore the relationship among Anishinaabe women's knowledges, self, identity, power relations, allyship, sovereignty and good governance in graduate research. I conclude that if graduate research is framed as an extension of an Anishinaabe space, an ethics of responsibility emerges, setting the stage for graduate research that is rooted in responsibility, contributing to efforts of Anishinaabe sovereignty and community wellness. Overall through my conclusion, as well as the process that I employ, I make contributions in the areas of Indigenous thought, Indigenous methodologies, Indigenous governance, feminism, critical theory, pedagogy, and ally theory.
Author Keywords: Anishinaabe, beadwork, Indigenous knowledge, Indigenous methodology, Indigenous women, sovereignty
Testing the Validity of Dental Calculus as a Proxy to Bone in Paleodietary Studies Using Stable Isotope Analysis
This study investigates the use of dental calculus for paleodietary studies using stable isotope analysis of a skeletal sample from the Greek colonial site of Apollonia Pontica, Bulgaria (5th to 3rd century BC). A sample of 27 individuals was used to examine the δ13C and δ15N values of paired dental calculus and bone samples, and the dental calculus was analyzed as separate organic and inorganic components. No significant correlation was found between the δ13C values of either the bone collagen and organic dental calculus samples, or the bone apatite and inorganic dental calculus samples. A significant correlation was found between the δ15N values of the bone collagen and organic dental calculus samples; however, the reason for this correlation is unclear. A greater range of variation in the δ13C and δ15N values was found in the organic dental calculus samples compared to the respective bone collagen samples. These results suggest that dental calculus is not an appropriate proxy to bone for paleodietary studies using stable isotope analysis and that any dietary signal is clouded by other data. The oral microbiome is considerably diverse and is the most probable explanation for the great range of stable isotope values obtained from dental calculus. A significant, strong correlation was found between the C/N ratios and δ15N values of the organic dental calculus samples, suggesting that the lowest C/N ratios and δ15N values depict deposits with the least bacterial alteration.
Author Keywords: carbon, dental calculus, nitrogen, paleodietary studies, Social Sciences, stable isotopes
Machine Learning Using Topology Signatures For Associative Memory
This thesis presents a technique to produce signatures from topologies generated by the Growing Neural Gas algorithm. The generated signatures have the following characteristics: The signature's memory footprint is smaller than the "real object" and it represents a point in the n x m multidimensional space. Signatures can be compared based on Euclidean distance and distances between signatures provide measurements of differences between models. Signatures can be associated with a concept and then be used as a learning step for a classification algorithm. The signatures are normalized and vectorized to be used in a multidimensional space clustering. Although the technique is generic in essence, it was tested by classifying alphabet and numerical handwritten characters and 2D figures obtaining a good accuracy and precision. It can be used for many other purposes related to shapes and abstract typologies classification and associative memory. Future work could incorporate other classifiers.
Author Keywords: Associative memory, Character recognition, Machine learning, Neural gas, Topological signatures, Unsupervised learning
Beyond Habitat: Individual and Population-Level Drivers of Coyote Space Use
My objective was to understand how individual variation, in conjunction with variation in habitat, can affect individual and population-level variation in animal space use. I used coyotes (Canis latrans) as a model species to investigate the roles of hybridization, an inherited intrinsic factor, and spatial memory, a learned intrinsic factor, on space use. I used a diversity of methods and approaches, including meta-regression, multiple imputation, simulations, resource selection functions, step selection functions, net-squared displacement analysis, and survival analysis. A major contribution was my investigation of the performance of multiple imputation in a meta-regression framework in Chapter 2. My simulations indicated that multiple imputation performs well in estimating missing data within a meta-regression framework in most situations. In Chapter 3, I used published studies of coyote home range size in a meta-regression analysis with multiple imputation to examine the relative roles of hybridization and environmental variables on coyote home range size across North America. I found that hybridization with Canis species was a leading factor driving variation in coyote space use at a continental scale. In Chapter 4, I used telemetry data for 62 coyotes in Newfoundland, Canada, to investigate the influence of cognitive maps on resource use. I found that resident coyotes used spatial memory of the landscape to select or avoid resources at spatial scales beyond their immediate sensory perception relative to transient coyotes, presumably increasing their fitness. Taken together, my dissertation demonstrates that intrinsic factors, such as genetic ancestry and spatial memory, can have substantial influences on how animals use space at both individual and population levels, and at both a local and a continental scales.
Author Keywords: canis latrans, hybridization, meta-regression, multiple imputation, Newfoundland, spatial memory
Lithic Raw Material Characterization and Technological Organization of a Late Archaic Assemblage from Jacob Island, Kawartha Lakes, Ontario
The objective of this thesis is to document and characterize the raw material and technological organization of a Late Archaic assemblage from Jacob Island, 1B/1C area (collectively referred to as BcGo-17), Peterborough County, Kawartha Lakes, Ontario. The purpose of this research is to gain a greater understanding of the Late Archaic period in central Ontario; particularly information on locally available raw material types (i.e., Trent Valley cherts) and regional interaction. My aim is to define the range of materials exploited for stone tool production and use, and to explore how variation in material relates to variation in economic strategies; I also complete a basic technological study. The collected data is then compared to temporally and geographically similar sites, and used to interpret possible relationships between acquisition practices, technology choices, and mobility. It was found that although the assemblage agrees with some of the mobility and raw material utilization models from south-western Ontario, many do not explain what was occurring on Jacob Island.
Author Keywords: Archaic, Lithic Economic Strategies, Lithic Raw Material, Lithic Technology, Ontario Archaeology, Trent Valley
Factors Influencing the Prioritization of Sites for Conservation on Private Land in Southern Ontario: A Case Study of the Nature Conservancy of Canada
Conservation organizations use strategic prioritization methods to order complex environments, evaluate landscapes, and distribute efficiently resources for conservation. This study explores how strategic prioritization decisions are made, drawing on a case study of the Nature Conservancy of Canada (NCC). This thesis identifies the factors affecting prioritization and their influence on the public perception of the NCC. The case study revealed that the NCC utilizes comprehensive science-based methods when prioritizing for conservation but its methods are also influenced by the 'opportunity function' (funding, threats, public/political support). How these factors are communicated depends on the audience (e.g. NCC Conservation Blueprints stress the scientific value of the environment; the NCC uses its media sources to emphasize the human-environment connection). These differences indicate the multi-dimensional nature of planning for conservation, its links to values emerging from science, politics, and society, and the need for collaborative conservation efforts and earning and maintaining public trust.
Author Keywords: biodiversity conservation priorities, collaboration, Nature Conservancy of Canada, opportunity function, private conservation organizations, science-based conservation
Environmental Health Management Practices in Indigenous Communities: A Case Study with Mississauga First Nation
Environmental factors play a critical role in the health and well-being of people worldwide and the distribution of the burden of disease associated with environmental causes is disproportionately high in marginalized populations, including First Nations. In this way, environmental health problems are as much social and political problems as environmental and must be addressed as such. In Canada, the division of responsibilities for environmental health, in combination with the jurisdictional complexities of health and environment regulation and service provision on-reserve creates a First Nations environmental health management system with significant gaps. This research set out to explore the question: What are the current strengths and challenges in First Nations environmental health policy and management? A qualitative exploratory design organized in two stages and employing key informant interviews, document review and a community case study was used to examine this topic. In the first stage a review of existing programs and policies applicable to Ontario First Nations and a series of interviews with key experts on the topic in the province were conducted. A conceptual framework of the core elements affecting environmental health management in First Nations communities was developed and then applied to a case study with Mississauga First Nation in Northern Ontario. The framework included five core elements: Environmental Health Jurisdiction and Responsibility; Participation in Environmental Health Decision-Making; Access to Environmental Health Resources, Communication of Environmental Health Information; and, Role and Influence of Leadership. The findings indicate that "internal" issues, like community-based decision-making and support for environmental health initiatives seem to be least affected by the "external" issues such as access to federal funding. The "internal" issues were also shown to be critically important factors having impacts on environmental health management practices and policies in Mississauga First Nation. While there are countless barriers associated with the "external" factors that have significant impacts on environmental health management practices and policies, this research suggest that the "internal" factors can potentially be the most important factors in creating positive change in this area and as a result warrant further study in order to improve the state of environmental health issues in First Nations.
Author Keywords: Community, Environmental Health, First Nations, Framework, Policy
Controlling the Feminine Body in Public: An Examination of Didactic Literature from the Reign of Charles VI of France, and its Focus on Movement
Within this project, I have identified a new pattern of instruction, surrounding women's bodies and their movement within the public space, present within didactic literature produced during the reign of Charles VI of France (1368-1422). This pattern, present in the texts Le livre du Chevalier de la Tour Landry pour l'instruction de ses filles, Le Menagier de Paris, Le livre des trois vertus and Mirroir des dames, sought to shame control women's physical presentation in public through use of imagery, stories and fear of pride. Using modern gendered body theory presented by Luce Irigaray and Judith Butler to examine the rise of this pattern, this project then concludes it represents an attempt of the social authority to present a passive feminine body in the public space in order to display male power during a time of social instability.
Author Keywords: body history, didactic literature, medieval education, medieval France, women, women's bodies