Browsing Department of Biology Graduate Theses by Publish Date
Now showing items 1-20 of 370
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The evolution of species' geographical range limits: an empirical test using two coastal dune plants, Camissonia cheiranthifolia (Onagraceae) and Abronia umbellata (Nyctaginaceae)
(2007-07-05)Every species has a limit to its geographic distribution. The problem is that we don’t really know why. Classical explanations propose that range limits occur where the ecological conditions overwhelm adaptation and ... -
Arsenic biotransformations in terrestrial organisms: A study of the transport and transformation of arsenic in plants, fungi, fur and feathers, using conventional speciation analysis and X-ray absorption spectroscopy
(2007-07-05)Arsenic taken up by plants and fungi from contaminated soils can subsequently be introduced into food chains. Given the toxic properties of some arsenic compounds, this may be a cause for concern. Much remains to be learned ... -
Responses of zooplankton community structure and ecosystem function to the invasion of an invertebrate predator, Bythotrephes longimanus
(2007-07-20)Freshwater ecosystems face unprecedented levels of human-induced stresses and it is expected that the invasion of non-indigenous species will cause the greatest loss of biodiversity in lakes and rivers worldwide. Bythotrephes ... -
Assessing the spatial and temporal patterns of total mercury δ 15N and δ13C in yellow perch and their prey items from a contaminated site, St. Lawrence River, Cornwall, ON
(2007-08-02)As a result of the legacy of industrial contamination over the last century, areas of sediment deposition in the St. Lawrence River at Cornwall, ON, contain high concentrations of mercury (Hg). The popular sport-fish ... -
Phytoextraction of lead from contaminated soil by Panicum virgatum L. (switchgrass) and associated growth responses
(2007-08-02)Growing interest in biomass crops for energy production has focused attention on Panicum virgatum L. (switchgrass) as a promising perennial feedstock native to much of North America. Switchgrass may be processed into ... -
Climate and environmental change inferred from diatom communities in Lake Challa (Kenya-Tanzania)
(2007-08-09)Lake Challa is a 5 km2, 97m deep freshwater crater lake located at 880m elevation on the southeast slope of Mount Kilimanjaro (Kenya-Tanzania). Information gained from a preliminary limnological survey of Lake Challa, ... -
Limnological and paleolimnological investigations of environmental change in three distinct ecosystem types, Canadian High Arctic
(2007-09-19)The biological remains preserved in the sediments of Arctic lakes and ponds in the Canadian High Arctic are important indicators of environmental change, especially as long-term instrumental data are often lacking. Although ... -
Isolation and Characterization of Plastidic Glucose-6-Phosphate Dehydrogenase (G6PDH) from Castor (Ricinus communis L.)
(2007-09-27)Abstract Plant cells contain plastids, organelles dedicated to performing specific biochemical processes including photosynthesis, starch and oil biosynthesis. Fatty acid biosynthesis in oil seeds occurs in one type ... -
Chemical and biological recovery of Killarney Park, Ontario Lakes (1972-2005) from historical acidification
(2007-10-01)Forty-five lakes in Killarney Provincial Park and the surrounding area in south-central Ontario, Canada, were sampled for crustacean zooplankton and water chemistry in the summer of 2005. For each of the lakes, we had ... -
Effect of nutritional status on phenotypic characteristics of Arabidopsis and alfalfa in relation to the expression of AtSnRK2.9
(2007-10-01)The mechanisms of plant response to nutrient limitation and utilisation are of great interest for agricultural purposes. Phosphate is a non-renewable resource and is one of the most important nutrients required for plant ... -
Targeted over-expression of hsp22 and the maintenance of locomotor activity of third instar larvae of Drosophila melanogaster at high temperatures
(2007-10-02)Hsp22 has been implicated in stress tolerance and longevity in various organisms though its role in Drosophila melanogaster larval thermal tolerance has not yet been investigated. I undertook this project to determine if ... -
Measuring the influence of winter conditions on largemouth bass behaviour using both biotelemetry and laboratory studies
(2007-10-03)Studying the winter ecology of freshwater fishes has been a focus of much past and present research. Because of obvious constraints with studying fish in situ during the winter, few studies have made links between laboratory ... -
Characterization of Farnesoic Acid O-Methyltransferase (FAMeT) and Juvenile Hormone Acid Methyltransferase (JHAMT) in relation to Drosophila melanogaster Juvenile Hormone Biosynthesis
(2007-10-04)Juvenile hormones (JHs) are key regulators of both metamorphosis and adult reproductive processes. The role of two key enzymes in the biosynthetic pathway of JH were examined: Farnesoic Acid O-Methyltransferase (FAMeT) ... -
Probing Immune Function During Aging in Adult Drosophila
(2007-10-10)Virtually all multicellular organisms rely on a highly conserved innate immune system for defense against foreign microorganisms. Innate immunity consists primarily of a humeral response that culminates in the expression ... -
Allometric Scaling in Centrarchid Fish: Origins of Intra- and Inter-specific Variation in Oxidative and Glycolytic Enzyme Levels in Muscle
(2007-11-01)The influence of body size on metabolic rate, muscle enzyme activities, and the underlying patterns of mRNA for these enzymes were explored in an effort to explain the genetic basis of allometric variation in metabolic ... -
Determining the distribution and fate of mercury in sediments of the Cataraqui River at Kingston, Ontario
(2007-11-02)The Cataraqui River, which drains 930 square km of watershed before emptying into the inner harbour of Kingston, Ontario (pop: 113,000), has a long history of anthropogenic use. More than 40 industries have existed within ... -
Spatial, temporal and dendrochronological comparisons of mercury in Ontario deciduous trees
(2007-12-20)Mercury (Hg) research in Ontario has centered on aquatic environments since fish can be a significant source of methylmercury for humans. Interactions between terrestrial and aquatic environments in regards to the Hg ... -
Characterization of the locust retinoid X receptors
(2007-12-20)The retinoid X receptor (RXR) participates in a multitude of nuclear receptor signaling pathways and is induced by its highly sought-after cognate ligand, 9-cis-retinoic acid (9-cis-RA). In flies and moths, molting is ... -
Soil carbon and nitrogen dynamics along replicated chronosequences of abandoned agricultural lands in southeastern Ontario
(2007-12-20)Widespread abandonment of agricultural land has occurred in northeastern North America over the past two centuries. Soil carbon often increases as sites naturally regenerate towards perennial grasslands or forests. ... -
Identification of components in crude oil that are chronically toxic to the early life stages of fish
(2008-01-02)The risk of crude oil exposure to the early life stages (ELS) of fish is difficult to assess, given the complexity of the chemical composition of different oils. The aromatic portion of crude oil contains polycyclic aromatic ...