Graduate Theses & Dissertations

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Spatial and Temporal Variation in Peatland Geochemistry in Sudbury, Ontario, Canada
The damage to Sudbury's landscape from over a century of smelter and logging activity has been severe and impacts well documented. However, despite their abundance in the region, wetlands have received little attention. Recent studies have identified that nutrient limitation is as much a problem as metal toxicity and highlighted not only the importance of wetlands but also the need for more detailed studies examining the role of wetlands in the recovery of lakes. The objective of this work is to characterize the spatial and temporal variability in the geochemistry of 18 wetlands (poor fens) surrounding Sudbury, Ontario. Peat and water chemistry in the wetlands exhibited large spatial and temporal variability. Copper and Ni concentrations in surface peat decreased with distance from the largest smelter in the area, but water chemistry was also strongly influenced by natural factors such as climate, groundwater and peat carbon content. Redox processes contribute greatly to temporal variation in pore-water chemistry: the August and October campaigns were characterized by higher SO4, lower pH and higher concentrations of metals such as Ni, Cu and Mn compared with the May campaign. Other factors contributing to the temporal variability in pore water chemistry include DOC production, senescence and water source. Despite the large variability, soil-solution partitioning can be explained by pH alone for some metals. Modeling is significantly improved with the addition of other variables representing dissolved organic matter quality and quantity, sulphate concentration and hydrology. Author Keywords: metal contamination, metal mobility, organic matter quality, peatland geochemistry
Demography of a Breeding Population of Whimbrel (Numenius phaeopus) Near Churchill, Manitoba, Canada
I used a GIS raster layer of an area in the Churchill, Manitoba region to investigate the effect of breeding habitat on demography and density of Whimbrel from 2010 through 2013. Program MARK was used to quantify adult and daily nest survival. Apparent annual survival of 0.73 ± 0.06 SE (95% CI = 0.60-0.83) did not significantly differ between sexes or habitats and was lower than expected based on longevity records and estimates for other large-bodied shorebirds. Nest success, corrected for exposure days, was highly variable, ranging from a low of 3% (95% CI = 0-12%) in 2011 to a high of 71% (95% CI = 54-83%) in 2013. The highest rate of nest survival occurred in the spring with the warmest mean temperature. I developed a generalized linear model (GLM) with a negative-binomial distribution from random plots that were surveyed for abundance to extrapolate a local breeding population size of 410 ± 230 SE and density of 3.2 birds per square km ± 1.8 SE. The result of my study suggests that other aspects of habitat not captured by the land cover categories may be more important to population dynamics. Author Keywords: abundance, apparent survival, curlew, land cover map, nest-site fidelity, nest success
An Investigation of Load Balancing in a Distributed Web Caching System
With the exponential growth of the Internet, performance is an issue as bandwidth is often limited. A scalable solution to reduce the amount of bandwidth required is Web caching. Web caching (especially at the proxy-level) has been shown to be quite successful at addressing this issue. However as the number and needs of the clients grow, it becomes infeasible and inefficient to have just a single Web cache. To address this concern, the Web caching system can be set up in a distributed manner, allowing multiple machines to work together to meet the needs of the clients. Furthermore, it is also possible that further efficiency could be achieved by balancing the workload across all the Web caches in the system. This thesis investigates the benefits of load balancing in a distributed Web caching environment in order to improve the response times and help reduce bandwidth. Author Keywords: adaptive load sharing, Distributed systems, Load Balancing, Simulation, Web Caching
Productive Capacity of Semi-Alluvial Streams in Ontario
Changes in climate and land-use practices are leading to higher peak flows and increased transport capacity of channel substrate. Semi-alluvial streams underlain by bedrock or clay were examined to understand the potential impacts of alluvium loss on the biological community and overall productive capacity of semi-alluvial rivers. More specifically, this research investigates the productivity of gravels, bedrock, and consolidated clay, through the biomass and density of periphyton, coarse particulate organic matter, benthic invertebrates, and fish. The ecological approach undertaken demonstrates the relationships among each trophic level and linkages to productive capacity between different substrate types. Significant results were detected at the stream type level and substrate level. Bedrock-based streams were overall more productive in terms of CPOM, biomass and density of benthos in comparison to clay-based streams. Stream reaches with small to large areas of exposed bedrock or clay at the site level did not differ to areas with 100% gravel coverage in the comparison of any variable, including stream fishes. At the substrate level, gravels demonstrated the highest productive capacity in comparison to bedrock and clay substrates. CPOM biomass in gravels compared to bedrock and clay at a ratio of 30:14:1, respectively. Biomass of benthic invertebrates also demonstrated a higher productivity on gravels with a ratio of 59:19:1 in comparison to bedrock and clay, respectively. Positive relationships between CPOM and benthic invertebrate biomass were detected in both stream types. Relationships were also detected between fish biomass and benthic invertebrate biomass. Examination of benthic fishes also demonstrated positive relationships with benthic invertebrate biomass and density. Clay substrate on all accounts supported little biota. Results indicate alluvium loss in clay bed streams could reduce productive capacity. Understanding and integration of the potential impacts of alluvium loss would aid management and No Net Loss compensation plans to protect fisheries resources in semi-alluvial streams. Author Keywords:
Home range use, habitat selection, and stress physiology of eastern whip-poor-wills (Antrostomus vociferus) at the northern edge of their range
The distribution of animals is rarely random and is affected by various environmental factors. We examined space-use patterns, habitat selection and stress responses of whip-poor-wills to mining exploration activity.To the best of my knowledge, fine scale patterns such as the habitat composition within known home ranges or territories of eastern whip-poor-wills have not been investigated. Using a population at the northern edge of the distribution in an area surrounding a mining exploration site, we tested whether variations in habitat and anthropogenic disturbances influence the stress physiology of individuals. We found no effect of increased mining activity on the stress physiology of birds but found a significant scale-dependent effect of habitat on their baseline and stress-induced corticosterone levels, and we suggest that these are the result of variations in habitat quality. The importance of other factors associated with those habitat differences (e.g., insect availability, predator abundance, and microhabitat features) warrants further research. Author Keywords: anthropogenic disturbances, Antrostomus vociferus, corticosterone, eastern whip-poor-will, habitat selection, radio-­telemetry
Rewiring the State
ABSTRACT Rewiring the State: The Privatization of Information Technology in the Ontario Public Service (1972-2003) David Rapaport Senior managers in the Ontario Public Service (OPS) and neo-liberal public policy advocates rationalize the privatization of Information Technology (IT) as an organizational quest for new efficiencies, specifically efficiencies imported from market economies. The findings of the research for this study indicate that IT privatization frequently results in inefficiencies, dependencies and a loss of core skills. The explanation for widespread IT privatization must be sought elsewhere. This study researches and depicts two related IT developments. The first development is the evolution of IT privatization from the earlier practice of body-shopping, i.e. the hiring on contract of IT consultants to the more complex public private partnership. This evolution is a reflection of the maturation of privatization. Body-shopping informs the alienation of IT skills from the public sector, the shaping of a labour hierarchy based on skills distribution, and the foundation for the public-private partnership. The second development, the evolution of OPS management attitudes towards IT privatization, is a reflection of growing neo-liberal hegemony. Archival research indicates middle management disdain towards excessive IT privatization in the early 1980's; particularly its high costs, loss of skills and growing dependency on external private sources. By the ii late 1990's, parliamentary committee transcripts indicate IT management acceptance of more excessive IT privatization. As neo-liberal practice became more accepted and as governments and central ministries pressured line ministries through budgetary and organizational controls, IT managers accepted their new roles as authors of RFP's and tenders of public sector work. The IT service providing industry gladly bid on contracts and acquired the new skills required for future IT projects, exacerbating the provision/dependency cycle. Furthermore, the new technologies provided an ideological smokescreen of technological necessity to conceal the market forces that promoted and benefitted from IT privatization. "Why do managers in the Ontario Public Service privatize the production of Information Technology systems?" The dissertation has two tasks when answering this central question. First, it must refute the efficiency arguments. Second, it must formulate an answer within the context of neo-liberal state transformation, new investment strategies of IT service providing corporations and a restructured IT labour hierarchy. Author Keywords: neo-liberalism, New Public Management, Ontario, privatization, public private partnership, public sector
ECTOPARASITIC INFLUENCES OF DIPTERA ON THE ACTIVITY AND BEHAVIOUR OF WOODLAND CARIBOU (RANGIFER TARANDUS) IN A MANAGED BOREAL FOREST LANDSCAPE IN NORTHERN ONTARIO
Caribou experience direct and indirect negative effects of harassment from biting flies, influencing behavior and activity on several spatial and temporal scales. I used systematic insect collection surveys during the summers of 2011 and 2012 to examine the spatial and temporal distributions of black flies (Simuliidae), mosquitoes (Culicidae), and deer flies and horse flies (Tabanidae) in a managed boreal forest in northern Ontario. Mosquitoes had a positive association with densely treed habitats, whereas black flies more often occurred in open areas, and tabanids had a strong presence in all habitat types. Habitats in proximity to large bodies of water had fewer biting flies than inland areas. Young stands supported higher abundances of tabanids despite vegetation community type. Next, I tested for seasonal effects of biting fly abundance on caribou activity by modelling the seasonal trend in abundance for each fly family for each year and compared this to an index of daily activity for 20 radio-collared female caribou in 2011 and 10 females in 2012. I modeled this index of caribou activity for each animal in each year and extracted the set of partial correlation coefficients from multiple regressions to test for effects of biting fly abundances on caribou activity. Caribou reduced their daily activity when tabanids were more numerous, and increased activity when mosquitoes were numerous. This divergent response may reflect a difference in the efficacy of moving to reduce harassment, owing to the stronger flight capabilities of tabanids. Author Keywords: Activity, Anthropogenic Disturbance, Behaviour, Insect harassment, Temporal distribution, Woodland Caribou
TWO-DIMENSIONAL CONDUCTIVITY AT LaAlO3/SrTiO3 INTERFACES
Experiments have observed a two-dimensional electron gas at the interface of two insulating oxides: strontium titanate (SrTiO3) and lanthanum aluminate (LaAlO3). These interfaces exhibit metallic, superconducting, and magnetic behaviours, which are strongly affected by impurities. Motivated by experiments, we introduce a simple model in which impurities lie at the interface. We treat the LaAlO3 as an insulator and model the SrTiO3 film. By solving a set of self-consistent Hartree equations for the charge density, we obtain the band structure of the SrTiO3 film. We then study the relative contributions made by the occupied bands to the two-dimensional conductivity of the LaAlO3/SrTiO3 interface. We find that the fractional conductivity of each band depends on several parameters: the mass anisotropy, the filling, and the impurity potential. Author Keywords: conductivity, impurities, insulating oxides, Two-dimensional electron gases
Archaeology of Vagabondage
My research examines the figure of the 'vagabond' as a case study to illustrate how 'modern' perception of the 'vagabond' has depleted the diversities in its 'pre-modern' counterparts. It argues that the paranoia towards the 'vagabond' was inherited from the west out of the colonial contact leading to the birth of the nation-state and its liaison with 'instrumental rationality' during the high noon of advanced industrial capitalism, while (quasi-religious) itinerancy, on the contrary, had always been tolerated in 'pre-modern' India. The problems I am addressing are: What is the line of thread that separates the 'traveler' from the 'vagabond', the 'explorer' from the 'wanderer'? How do we then politically account for the historic 'ruptures' in the vagabond having been tolerated in the ancient 'Indic' thought [cf. Manusmriti, Arthshastra], encouraged in early Buddhist discourse [cf. Samannaphala Sutta], revered as the 'holy Other' in the Middle Ages [cf. Bhakti-Sufi literature], and eventually marginalized in the 'modern'? While considering issues of cultural differences, my thesis points to how the epistemic shifts from the classical to the medieval, from the medieval to the modern radically alter the value system immanent in the figure of the 'vagabond'. The research argues that the cultural baggage that the expression 'vagabond' is generally associated with, is a product of a specific western/utilitarian value system, which is a distinct 'cultural' category of the 'modern' west that had no resonance in 'pre- modern' India, and hence cannot be necessarily universalizable. The project works in a number of registers: historical, archival, cultural, philosophical and representational, involves analysis of literary, filmic texts, also legislative documents, and is genuinely interdisciplinary in nature. As of discourse analysis, the project studies the politics of cultural representations both of and by 'vagabonds'. Author Keywords: 1943 Bengal Famine, Homelessness, India, Vagabond, Vagrancy, Vagrancy Act
Tabanidae and Culicidae in the Northern Boreal Region of Ontario
I studied the abundance, distribution and diversity of horse fly and deer fly species (Diptera: Tabanidae) and mosquito species (Diptera: Culicidae) in the boreal forest region of northern Ontario in 2011 and 2012. I collected 19 mosquito species, including one species new for Ontario, Aedes pullatus (Coquillett). I documented 11 northern and one southern range extension. I also collected a total of 30 species of horse and deer flies, including one new species of horse fly for Ontario, Hybomitra osburni (Hine). Results were inconsistent with a hypothesis of colonization of dipteran species from west to east. I examined the trapping biases of Malaise and sweep sampling for horse and deer flies and found that Malaise traps collected fewer individuals than sweep netting (850 versus 1318) but more species (28 versus 22). Consequently, I determined that surveys of diversity benefit from the use of multiple trapping methods. I also examined how blood-feeding (anautogeny) requirements affect the distribution patterns of Tabanidae. Ultimately, there are likely multiple factors that affect the expression of anautogeny in Tabanidae. Author Keywords: Autogeny, Culicidae, Diversity, Hudson Bay Lowlands, Northern Ontario, Tabanidae
Maintaining Balance in Times of Change
Abstract Maintaining Balance in Times of Change: An Investigation into the Contemporary Self-Regulatory Dynamics that Operate in and around First Nations Traditional Healing Systems The evolution of health regulation processes in Canada has focused on the development of standards of practice premised upon the principle of `do no harm' and the approval of these by government regulatory agencies. This thesis examines three emerging communities of practice that bring traditional indigenous knowledge and indigenous healers forward into health care and their approaches to regulation. The results indicate that surrounding contexts of meaning influence understandings about self-regulation and that these understandings are dynamic because contemporary practices of First Nations traditional healing can occur in different contexts. The study cautions that unless we remain close to these `healer centred' contexts, there is no guarantee that the self-regulatory value systems stemming from modern Western medical communities of practice will not be applied by default or that the emerging `integrative' models of self-regulation developed between governments and First Nations will continue to reflect First Nations' understanding of self-regulation. Author Keywords: health and wellness, indigenous, self-determination, self-regulation, traditional healing
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

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Format: 2023/02/04