Graduate Theses & Dissertations

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Fractionation of Mercury Isotopes in an Aqueous Environment
Fractionation of mercury isotopes in an aqueous environment: Chemical Oxidation Dimitri Stathopoulos The study of fractionation patterns for the stable isotopes of mercury is a growing field. The potential for stable isotopes to trace mercury through the environment from pollution sources to sinks make the subject interesting to geochemists and useful to a wider audience. The purpose of this study is to measure the fractionation of mercury as it is oxidized in an aqueous medium. Samples in this study are prepared by chemically oxidizing different proportions of elemental mercury using four different oxidants. The oxidized portion is then separated from the elemental portion and an analysis of the isotope ratios for both portions is performed using a multicollector inductively coupled plasma mass spectrometer MC-ICP/MS. These isotope ratios are measured against the preoxidation isotope ratio to determine what if any change has occurred. From the findings of this work, it is now known chemical oxidation causes both mass dependent and mass independent fractionation. Mass dependent fractionation causes an enrichment of the heavier isotopes in the oxidized portion while the opposite is true for the elemental portion. Mass independent fractionation occurred only in the odd isotopes and causes a depletion of odd isotopes in the oxidized portion and enrichment in the elemental portion. These trends were found to be true for all oxidants tested as the pattern of fractionation does not change with varying oxidants. Author Keywords: Isotope, Mass Dependent, Mass Independent, Mercury, Oxidation
THE LIFE HISTORY STRATEGY, GROWTH, BODY CONDITION, AND DIET OF STOCKED AMERICAN EEL (Anguilla rostrata) IN THE UPPER ST. LAWRENCE RIVER AND LAKE ONTARIO
My study was primarily focused on the comparison of life history traits between stocked American eel and their naturally recruited conspecifics in Lake Ontario and the upper St. Lawrence River (USLR/LO). I found that stocked eels experienced faster annual growth than their naturally recruited conspecifics and were comprised of a greater proportion of males. These findings indicate that the life history patterns of American eel may be genetically predisposed. Additionally, my study served to characterize the diets of stocked American eel and examine possible associations between eel and prey size. The eels consumed a number of macroinvertebrate prey orders as well as fishes and macrocrustaceans, with the latter prey items being more prevalent in the diets of larger eel specimens. A disparity in eel growth and body condition was observed between two primary stocking locations and were likely attributable to differences in available forage and habitat. Lastly, growth, body condition, and stocked eel diet were compared between lentic and lotic habitats. Eels from lotic streams experienced slower annual growth and had reduced body condition, and their diets were comprised of smaller prey items. The results of this study suggest that the current stocking methods employed in the USLR/LO are not suitable to restore the natural recruitment of individuals that will exhibit desired life history traits. Author Keywords:
Immunogenetic Responses of Raccoons and Skunks to the Raccoon Rabies Virus
Interactions between hosts and pathogens play a crucial role in their adaptation, evolution and persistence. These interactions have been extensively studied in model organisms, yet it is unclear how well they represent mechanisms of disease response in primary vectors in natural settings. The objective of my thesis was to investigate host-pathogen interactions in natural host populations exposed to raccoon rabies virus (RRV). RRV is endemic to North America, that causes acute encephalopathies in mammals and is commonly regarded as 100% lethal if untreated; however variable immune responses have been noted in natural reservoirs. In order to further understand variable immune responses to RRV, my thesis examined (i) potential immunogenetic associations to RRV using genes intimately associated with an immune response, (ii) the nature of immune responses triggered in the host after infection, and (iii) viral expression and genetic variation, to provide insight into factors that may influence RRV virulence. Immunogenetic variation of RRV vectors was assessed using major histocompatibility complex (MHC) DRB alleles. Associations were found between specific MHC alleles, RRV status, and viral lineages. Further, similarities at functionally relevant polymorphic sites in divergent RRV vector species, raccoons and skunks, suggested that both species recognize and bind a similar suite of peptides, highlighting the adaptive significance of MHC and contemporary selective pressures. To understand mechanisms of disease spread and pathogenesis, I screened for variation and expression of genes indicative of innate immune response and patterns of viral gene expression. RRV activated components of the innate immune system, with transcript levels correlated with the presence of RRV. These data indicate that timing of the immune response is crucial in pathogenesis. Expression patterns of viral genes suggest they are tightly controlled until reaching the central nervous system (CNS), where replication increases significantly. These results suggest previous molecular mechanisms for rabies host response derived from mouse models do not strictly apply to natural vector populations. Overall my research provides a better understanding of the immunological factors that contribute to the pathogenesis of RRV in a natural system. Author Keywords: immune response, major histocompatibility complex, rabies, raccoons, skunks, virus
maskihkîyâtayôhkêwina; mashkikiiwaadizookewin
maskihkîyâtayôhkêwina- mashkikiiwaadizookewin: Cree and Anishnaabe Narrative Medicine in the Renewal of Ancestral Literature Jud Sojourn This work represents an experiment in developing Cree and Anishnaabe nation-specific approaches to understanding Cree and Anishnaabe texts. The binding premise that guides this work has to do with narrative medicine, the concept that narrative arts, whether ancestral storytelling or current poetry have medicine, or the ability to heal and empower individuals and communities. As âtayôhkêwin in Cree and aadizookewin in Anishnaabemowin refer to ancestral traditional narratives, and while maskihkiy in Cree, and mashkiki in Anishnaabemowin refer to medicine, maskihkîyâtayôhkêwina and mashkikiiwaadizookewin mean simply `narrative medicine' in Cree and Anishnaabemowin respectively. After establishing a formative sense for what narrative medicine is, this work continues by looking at the bilingual Ojibwa Texts (1917, 1919) transcribed by William Jones in 1903-1905 on the north shore of Lake Superior and in northern Minnesota Anishnaabe communities, those spoken by Anishnaabe community members Gaagigebinesiikwe, Gaagigebinesii, Midaasookanzh, Maajiigaaboo, and Waasaagooneshkang. Then focus then turns to the bilingual Plains Cree Texts (1934) transcribed by Leonard Bloomfield at the Sweet Grass Reserve in Saskatchewan and spoken by Cree community members nâhnamiskwêkâpaw, sâkêwêw, cicikwayaw, kâ-kîsikaw pîhtokêw , nakwêsis, mimikwâs, and kâ-wîhkaskosahk. The themes that emerge from looking at these texts when combined with an appreciation for the poetics of the Cree and Anishnaabe languages provide the foundation for looking at newer poetry including the work of Cree poet Skydancer Louise Bernice Halfe, centering on the contemporary epic prayer-poem The Crooked Good (2007) and the works of Anishnaabe poet Marie Annharte Baker, focusing on Exercises in Lip Pointing (2003). Each poet emerged as having an understanding her own role in her respective nation as renewing the narrative practices of previous generations. Understandings of the shape or signature of each of the four works' unique kind of narrative medicine come from looking at themes that run throughout. In each of the four works the maskihkîyâtayôhkêwina - mashkikiiwaadizookewin, the narrative medicine they express occurs through or results in mamaandaawiziwin in Anishnaabemowin or mamâhtâwisiwin, in Cree - the embodied experience of expansive relationality. Keywords: Cree, Anishnaabe, nêhiyawêwin, Anishnaabemowin, narrative medicine, traditional stories, poetics, poetry, literary criticism, literary nationalism, Indigenous, indigenist. Author Keywords: Anishnaabe, Anishnaabemowin, Cree, Indigenous, nêhiyawêwin, Poetics
Analysis and reactions of aqueous selenide and other reduced inorganic selenium compounds under anoxic conditions
Selenide is cited as a geochemically important selenium (Se) species, but it is unknown whether selenide is a stable aqueous ion in natural waters. The feasibility of using anoxic anion exchange chromatography (AEC) coupled to dynamic reaction cell-inductively coupled plasma-mass spectrometry to separate aqueous selenide was investigated with the goal of quantifying this anion to determine its importance in reducing waters. It was possible to qualitatively identify selenide using AEC, but much of the aqueous selenide oxidises to Se0 faster than the separation procedure could be completed. AEC analyses of solutions containing polyselenides produced peaks for unidentified Se compounds, which have been assigned tentative structures Se2O22-, Se2O32-, and Se2O62- based on close matches in retention time to stable S compounds. The results of this work show that aqueous selenide can be qualitatively observed in synthetic solutions using AEC, but it is unknown whether these conditions are relevant to natural waters. Author Keywords: anoxic speciation, polyselenides, selenide, selenium geochemistry, selenium speciation, selenoselenate
Nymphs, Satyrs and Impotent Old Men
British pornographic texts arguing the texts were part of a wider cultural discourse on luxury, criticising the upper echelons of society for their decadent and vice-ridden lifestyles. Pornographic texts consistently portray the elites of Britain as partaking in sexual deviances including lesbianism, sex with dolls, dildos and household objects. The portrayals could be dismissed as tales fabricated for the titillation of the reading audience except that medical texts of the period diagnose the diseases of nymphomania and satyriasis, the rough equivalent of modern sexual addiction, as primarily affecting those of the upper class. Lifestyle was the key to diagnosis; luxurious living was thought to weaken the elite body rendering it vulnerable to excess sexual passions. Therefore, the hyper-sexual elite in pornographic texts reflected the contemporary cultural understandings of lifestyle and physiology. Author Keywords: Britain, culture, eighteenth century, nymphomania, pornography, sexuality
Influence of Habitat on Woodland Caribou Site Fidelity
Site fidelity is the behaviour of individuals to return to the same location; for female woodland caribou it may reflect reproductive success and depend on habitat quality. I investigated the influence of landscape and disturbance conditions on fidelity among three populations in Manitoba and Ontario, Canada. Habitat classifications were based on Forest Resource Inventory (FRI) and Landsat TM landcover maps. A total of 261 sites were ground-truthed to determine mapping accuracy. An amalgamated map incorporating FRI and Landsat TM data was estimated from field measurements to have an overall accuracy of 69.0%. Site fidelity was expressed as the distance between consecutive-year locations of individuals and was investigated during five week-long periods representing calving, early and late post-calving, winter, and breeding. Site fidelity was strongest during the post-calving seasons and weakest during the winter. Habitat had little influence on site fidelity in all seasons, excepting winter, even under highly disturbed conditions, suggesting maintenance of fidelity may be a maladaptive trait. Individual variation proved a strong predictor and cursory mapping indicated that caribou may return to sites visited two or more years earlier. Conservation management and policy should recognize that site fidelity may represent an ecological trap. Author Keywords: calving, disturbance, habitat, movement, Rangifer tarandus caribou, site fidelity
Childhood diet and feeding practices at Apollonia
This study analyses deciduous dental pathology and stable carbon and nitrogen isotopes to investigate the relationship between dietary composition, feeding practices, and oral health in a subadult skeletal sample from the Greek colonial site of Apollonia Pontica, Bulgaria (5th to 3rd century BC). Stable isotope analysis of 74 bone collagen samples indicates that weaning began between the ages of 6 months and 1 year, and was complete by the age of 4. The stable isotope data are consistent with a diet of primarily terrestrial C3 resources. The deciduous dentitions of 85 individuals aged between 8.5 months and 10.5 years were examined for evidence of a number of pathological conditions. The presence of dental caries, calculus, occlusal tooth wear and an abscess indicate that foods introduced early in life affected the oral health of these individuals. Overall, the deciduous dental data correlate well with the stable isotope data and ancient textual sources regarding infant and childhood dietary composition and feeding practices. Author Keywords: breastfeeding, deciduous dentition, dental pathology, stable carbon and nitrogen isotopes, weaning
Sustainable Development
While there is an emerging body of literature on the role and effectiveness of community-based research (CBR) in addressing the needs of local communities, few studies have explored its promise in areas lacking established collaborative models. The purpose of this paper is to examine the potential of CBR to meet the sustainable community development needs of the primarily urban Durham Region in Southern Ontario. Semi-structured interviews with twenty sustainability-focused community members from the academic, municipal, private and non-profit sectors were conducted using Glaser and Strauss' grounded theory to develop a working hypothesis that was analyzed with the aid of the qualitative data software program ATLAS.ti. The results reveal that while the region's academic and community groups have little time to initiate formal community-campus collaborations, the additional manpower and expertise that a well-structured CBR model provides could significantly assist local organizations complete unfinished projects and undertake new initiatives. Author Keywords: Community-based research, Community-campus collaboration, Cooperative education, Durham Region, Experiential education, Sustainable development
ARROWS before AGRICULTURE? A FUNCTIONAL STUDY of NATUFIAN and NEOLITHIC GROOVED STONES
Grooved stones first appear in the Southern Levant with the development of the Natufian culture (~15,000 - 12,000 BP). These tools come in a variety of shapes and sizes; however, they share in common the presence of an intentionally manufactured groove. This thesis focuses on a few types of grooved stones, specifically, those which are often considered to be straighteners for arrow-shafts. If this interpretation is correct, then these tools represent the only clear evidence of the bow and arrow prior to the Neolithic (~12,000 - 6,500 BP), which has implications for our understanding of changing hunting strategies in the millennia leading up to the origins of agriculture. Using an experimental and use-wear approach, I analyse a sample of grooved stones from three Natufian and Neolithic sites in Northern Israel, the results of which generally support the arrow-shaft straightener interpretation. Furthermore, by placing grooved stones in their broader technological context, it becomes apparent that they represent progression and diversification of long-range projectile weapons, which likely existed even earlier in time Author Keywords: grooved stones, Natufian, Neolithic, PPNB, use-wear analysis
Class Struggle and Solidarity in Neo-Liberal Times
The lengthy and raucous 1986 Gainers meatpacking plant strike in Edmonton, Alberta was one of the most important events in recent Alberta labour history. In the midst of the economic crisis of the 1980s and the rise of neo-liberal ideas, the strike marked a backlash by both the labour movement and ordinary citizens against attacks on workers and unions. Characterized by widely covered picket line violence, repressive police and court actions, and government unresponsiveness, the strike generated massive solidarity within and beyond the labour movement. This solidarity originated in a rejection of the neo-liberal new reality of Alberta typified by high unemployment, anti-union laws and practices, and lack of government welfare support, and it generated a provincial change the law campaign, national boycott, and rising class consciousness. The working class mobilization during the Gainers strike was a watershed for the Alberta labour movement. Author Keywords: Alberta Federation of Labour, Gainers strike, neo-liberalism, solidarity, working class
Elite Canadian Print Media Construction of the Cuban Revolution, 1956-1962
This study examines the elite national print media reaction to, and coverage of, the Cuban Revolution, between 1956 and 1962. It finds that media, equally alienated by both Fidel Castro and the United States, progressively pursued an independent narrative predicated on an homage to Cuban sovereignty. Specifically, media uniformly adopted veteran New York Times' reporter Herbert L. Matthews' conflation between Cuban postcolonial independence and the Revolution following his exclusive interview with Fidel Castro in February 1957. Media maintained it until 1962 as it remained the only consistent, defensible theme amid Castro's apparent failure to meet expectations and the United States' cautious indifference to a revolution in kind and abject disregard for Cuban sovereignty. Research is based on an exhaustive review of eleven carefully selected elite broadsheets and three national magazines. Overall, this study offers an important counterpoint to the broader body of Canada-Cuba-U.S. postwar historiography that almost exclusively addresses foreign policy. Author Keywords: Canada-Cuba-U.S. relations, Canadian print media, Cuban Revolution, Fidel Castro, Herbert L. Matthews, journalism

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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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