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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Early Feeding In Lake Trout Fry (salvelinus Namaycush) As A Mechanism For Ameliorating Thiamine Deficiency Complex

Kozel, Carrie L. 01 January 2017 (has links)
Recruitment failure of lake trout (Salvelinus namaycush) in the Great Lakes has been attributed in part to the consumption of alewife (Alosa pseudoharengus) by adult lake trout, leading to Thiamine Deficiency Complex (TDC) and early mortality in fry. The current understanding of thiamine deficiency in lake trout fry is based on information from culture and hatchery settings, which do not represent conditions fry experience in the wild and may influence the occurrence of TDC. In the wild, lake trout fry have access to zooplankton immediately following hatching; previous studies found that wild fry begin feeding before complete yolk-sac absorption. However, hatchery-raised fry are not provided with food until after yolk-sac absorption, long after the development of TDC. Zooplankton are a potential source of dietary thiamine for wild fry in the early life stages that has not previously been considered in the occurrence of thiamine deficiency. We postulated that wild-hatched fry could mitigate thiamine deficiency through early feeding on natural prey. Specifically, we hypothesized 1) feeding should increase thiamine concentrations relative to unfed fry and 2) feeding should increase survival relative to unfed fry. Feeding experiments were conducted on lake trout fry reared from eggs collected from Lake Champlain in 2014 and Cayuga Lake in 2015. A fully crossed experimental design was used to determine the effect of early feeding by lake trout fry in thiamine replete and thiamine deplete treatments before and after feeding. Overall, thiamine concentrations and survival did not significantly differ between fed and unfed fry. Thiamine concentrations increased from egg stage to hatching in both years, suggesting a potential source of thiamine, which had not previously been considered, was available to the lake trout eggs during development.
122

Stable isotope mass balance of the North American Laurentian Great Lakes

Jasechko, Scott January 2011 (has links)
This thesis describes a method for calculating lake evaporation as a proportion of water inputs (E/I) for large surface water bodies, using stable isotope ratios of oxygen (18O/16O) and hydrogen (2H/1H) in water. Evaporation as a proportion of inflow (E/I) is calculated for each Laurentian Great Lake using a new dataset of 516 analyses of δ18O and δ2H in waters sampled from 75 offshore stations during spring and summer of 2007. This work builds on previous approaches by accounting for lake effects on the overlying atmosphere and assuming conservation of both mass and isotopes (18O and 2H) to better constrain evaporation outputs. Results show that E/I ratios are greatest for headwater Lakes Superior and Michigan and lowest for Lakes Erie and Ontario, controlled largely by the magnitude of hydrologic inputs from upstream chain lakes. For Lake Superior, stable isotopes incorporate evaporation over the past century, providing long-term insights to the lake’s hydrology that may be compared to potential changes under a future – expectedly warmer – climate. Uncertainties in isotopically derived E/I are comparable to conventional energy and mass balance uncertainties. Isotope-derived E/I values are lower than conventional energy and mass balance estimates for Lakes Superior and Michigan. The difference between conventional and isotope estimates may be explained by moisture recycling effects. The isotope-based estimates include only evaporated moisture that is also advected from the lake surface, thereby discounting moisture that evaporates and subsequently reprecipitates on the lake surface downwind as recycled precipitation. This shows an advantage of applying an isotope approach in conjunction with conventional evaporation estimates to quantify both moisture recycling and net losses by evaporation. Depth profiles of 18O/16O and 2H/1H in the Great Lakes show a lack of isotopic stratification in summer months despite an established thermocline. These results are indicative of very low over-lake evaporation during warm summer months, with the bulk of evaporation occurring during the fall and winter. This seasonality in evaporation losses is supported by energy balance studies. For Lakes Michigan and Huron, the isotope mass balance approach provides a new perspective into water exchange and evaporation from these lakes. This isotope investigation shows that Lake Michigan and Lake Huron waters are distinct, despite sharing a common lake level. This finding advocates for the separate consideration of Lake Michigan and Lake Huron in future hydrologic studies.
123

Bioenergy Systems in Canada: Towards Energy Security and Climate Change Solutions

Hacatoglu, Kevork 10 December 2008 (has links)
The energy security and climate change risks of fossil fuel consumption have stimulated interest in developing renewable energy sources. Canada’s vast biomass potential is an attractive local resource but high transportation costs are a barrier to implementation. This study assesses how transformative systems can enable large-scale bioenergy production through integration with existing transportation corridors and fossil fuel infrastructure. Potential bioenergy corridors include the network of natural gas pipelines and the Great Lakes St. Lawrence Seaway (GLSLS). Sustainable lignocellulosic biomass production integrated with traditional food and fibre production was assumed to occur on 196 Mha of land within 100 km of pipelines. Conservative (81 Mt of dry biomass per year) and aggressive (209 Mt) scenarios were investigated for converting biomass to synthetic natural gas (SNG) via gasification, methanation, and upgrading, yielding enough pipeline-quality gas to meet 20% to 60% of Canada’s current needs. A systems analysis approach was used to calculate bioSNG life-cycle emissions of 15 to 18 kgCO2e GJ-1, compared to 68 or 87 for conventional or liquefied natural gas, respectively. Production costs ranged from $16 to $20 GJ-1, which were high compared to regional gas prices ($5 to $10 GJ-1). The biomass potential on 125 Mha of land area within 100 km of the Canadian portion of the GLSLS and railway lines ranged from 36 to 80 Mt(dry) per year, which was enough to displace coal-fired power in Ontario plus produce 1.6 to 11 billion L of green diesel that could offset 14% to 96% of fossil diesel in GLSLS provinces. Life-cycle emissions ranged from 110 to 130 gCO2e kWh-1 for biopower (compared to 1030 for coal) and 20 to 22 kgCO2e GJ-1 for green diesel (compared to 84 for conventional diesel). Cost estimates ranged from $130 MWh-1 for biopower (compared to an average market power price of $54 MWh-1) and $28 to $36 GJ-1 for green diesel (compared to $16 to $24 GJ-1 for diesel). The auxiliary benefits (energy security, climate change, air quality, and rural development) were seen as justification for supportive bioenergy policies. / Thesis (Master, Environmental Studies) -- Queen's University, 2008-12-09 15:24:18.389
124

Ethnohistoric study of culture retention and acculturation among the Great Lakes and Oklahoma Odawa

Hinshaw, Michael Lloyd January 1996 (has links)
This study examines the history and culture of the Odawa people from their prehistory until the present time. This paper looks at a creation story of the Odawa to see how they perceived their own beginnings. Following this, there is an examination of the prehistory, protohistory and history of this people. The section on the history of this people is broken up into three major periods---French, British and American. In the course of this examination, it is discovered that they were originally part of the loosely structured Anishnaabeg (People), or the Ojibwa, Odawa and Potawatomi, which were made up of separate bands. They then coalesced into the Odawa, primarily under the influences of European contact. Finally, in the American period, they split into two main groupings---the Great Lakes and Oklahoma. This paper explores why the Oklahoma group ended up acculturated while the Great Lakes bands retained their culture. / Department of Anthropology
125

Stable isotope mass balance of the North American Laurentian Great Lakes

Jasechko, Scott January 2011 (has links)
This thesis describes a method for calculating lake evaporation as a proportion of water inputs (E/I) for large surface water bodies, using stable isotope ratios of oxygen (18O/16O) and hydrogen (2H/1H) in water. Evaporation as a proportion of inflow (E/I) is calculated for each Laurentian Great Lake using a new dataset of 516 analyses of δ18O and δ2H in waters sampled from 75 offshore stations during spring and summer of 2007. This work builds on previous approaches by accounting for lake effects on the overlying atmosphere and assuming conservation of both mass and isotopes (18O and 2H) to better constrain evaporation outputs. Results show that E/I ratios are greatest for headwater Lakes Superior and Michigan and lowest for Lakes Erie and Ontario, controlled largely by the magnitude of hydrologic inputs from upstream chain lakes. For Lake Superior, stable isotopes incorporate evaporation over the past century, providing long-term insights to the lake’s hydrology that may be compared to potential changes under a future – expectedly warmer – climate. Uncertainties in isotopically derived E/I are comparable to conventional energy and mass balance uncertainties. Isotope-derived E/I values are lower than conventional energy and mass balance estimates for Lakes Superior and Michigan. The difference between conventional and isotope estimates may be explained by moisture recycling effects. The isotope-based estimates include only evaporated moisture that is also advected from the lake surface, thereby discounting moisture that evaporates and subsequently reprecipitates on the lake surface downwind as recycled precipitation. This shows an advantage of applying an isotope approach in conjunction with conventional evaporation estimates to quantify both moisture recycling and net losses by evaporation. Depth profiles of 18O/16O and 2H/1H in the Great Lakes show a lack of isotopic stratification in summer months despite an established thermocline. These results are indicative of very low over-lake evaporation during warm summer months, with the bulk of evaporation occurring during the fall and winter. This seasonality in evaporation losses is supported by energy balance studies. For Lakes Michigan and Huron, the isotope mass balance approach provides a new perspective into water exchange and evaporation from these lakes. This isotope investigation shows that Lake Michigan and Lake Huron waters are distinct, despite sharing a common lake level. This finding advocates for the separate consideration of Lake Michigan and Lake Huron in future hydrologic studies.
126

Characterization of Forest Harvest Residue from the Great Lakes-St Lawrence Forests of South-eastern Ontario

Acquah, Gifty Ewurama 14 December 2010 (has links)
The use of fossil derived products and the environmental and economic problems associated with them have made a shift to abundant renewable resources such as forest biomass more attractive. However before forest biomass can be used as a resource, its properties must be known. This study determined the physical properties of heterogeneous biomass residues produced during harvesting on two operational forest sites within the Great Lakes-St Lawrence forest of south-eastern Ontario. Properties measured were moisture content, size distribution, bulk density, and wood-to-bark ratio; also thermo-chemical properties including elemental composition, thermal reactivity and energy content were measured. The effects of forest site and harvest type, storage and position in storage pile, on the properties of biomass were also investigated. Results of the study showed that the various heterogeneous forest harvest residues differed more physically than thermo-chemically for the different variables, and this affected biomass procurement more than the potential utilization options.
127

The Vulnerability of the Great Lakes Region to Waterborne Diseases in the Wake of Climate Change : A Literature Review

Tällö, Emma January 2017 (has links)
Clean drinking and recreational water is essential for human survival and contaminated water cause 1.4 million deaths worldwide every year. Both developing and developed countries suffer as a consequence of unsafe water that cause waterborne diseases. The Great Lakes region, located in the United States is no exception. Climate change is predicted to cause an increase in waterborne disease outbreaks, worldwide, in the future. To adapt to this public health threat, vulnerability assessments are necessary. This literature study includes a vulnerability assessment that describes the main factors that affect the spreading of waterborne diseases in the Great Lakes region. Future climate scenarios in the region, and previous outbreaks are also described. The study also includes a statistical analysis where mean temperature and precipitation is plotted against waterborne disease cases. The main conclusion drawn is that the Great Lakes region is at risk of becoming more vulnerable to waterborne diseases in the future, if it does not adapt to climate change.
128

PREDICTING SITE SUITABILITY FOR KUDZU (PUERARIA MONTANA) IN THE GREAT LAKES BASIN AND SURROUNDING REGION

Ashley M Kovach-Hammons (12462825) 26 April 2022 (has links)
<p> Kudzu (Pueraria montana) is an invasive woody vine widespread throughout the  southeastern United States, with recent studies predicting that its habitat will expand northward.  New occurrences and recent studies using climatic parameters suggest that the Midwestern  region of the United States is at the greatest risk of kudzu invasion. As there have already been  25 reports of kudzu within the Great Lakes basin, and no previous landscape models exist for the  basin, I developed probability models from existing spatial data (land cover, hydrology, geology,  annual precipitation, elevation, aspect, and known kudzu locations) using generalized additive,  bioclimate envelope, and maximum entropy methods. I further expanded each model to include  the basin and a 2.25-degree buffer in order to include 193 reported kudzu sites. For each  predictive model, I determined the area under the curve (AUC) for a receiver operating  characteristic curve (ROC) comparing false positive and false negative rates. I performed field  surveys at eight known sites of kudzu presence in Michigan, Indiana, and Ohio. Each presence  site was paired with a control (known kudzu absence site). I collected environmental data  including canopy cover, volumetric soil moisture, soil pH, litter depth, midstory species diversity  and diameter at breast height (DBH), and overstory basal area. Each environmental measure was  compared between kudzu presence and control survey sites as well as between in-basin and out?of-basin survey sites using a two-way ANOVA. Maximum entropy models produced the highest  AUC in both the basin and buffer models during model development. These models showed that  urban and disturbed habitats resulted in the greatest probability of potential habitat for kudzu. I  found no statistically significant differences in environmental characteristics between kudzu  absent and presence sites or between in- and out-of-basin sites, suggesting kudzu might be  dispersal-limited rather than limited by environmental characteristics. Continuing existing  management and further monitoring of kudzu spread is likely necessary to limit further  introduction and to mitigate spread of kudzu within the Great Lakes region.  </p>
129

LiDAR Based Coastal Dune Elevation and Beach Change Assessment at Indiana Dunes National Park

Kostecky, Eric James January 2021 (has links)
No description available.
130

INVESTIGATING EUTROPHICATON AS A DRIVER OF METHANOGENESIS IN THE WESTERN BASIN OF LAKE ERIE

Helmer, Clare 31 July 2023 (has links)
No description available.

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