Digital Commons Network^™

Effects Of 100 Mt Static Magnetic Field Exposure On Cytosolic Free Ca2+ Levels And Hsp70 Reporter Gene Expression, Camilla Rozanski

Digitized Theses

Human exposure to electromagnetic fields has prompted investigations into possible effects of static magnetic fields (SMF)s on cellular processes. Discrepancies still remain between studies however, and are likely due to endpoint analysis on potentially small biological effects. The purpose of this research was to investigate the potential effect of SMF exposure on biological systems using real-time methods that are intrisicaly more sensitive than endpoint measurements. This research was divided into two main studies. The first study evaluated basal and activated levels of cytosolic free calcium in HL-60 cells before, during and after a 15 minute 100 mT SMF exposure. The …

Differential Cadmium Accumulation In Durum Wheat: Role Of Low Molecular Weight Organic Acids, Bolaji A. Adeniji

Digitized Theses

Pairs of isolines of durum wheat (Triticum turgidum var durum) differ in the amount of cadmium translocated to aboveground tissues; in the field, the high isolines have twice the cadmium in leaves and grain when compared to the low isolines. The hypothesis that differential cadmium translocation is associated with differential production of organic acids was tested by measuring cadmium in tissues, cadmium partitioning within the root, and organic acids in tissues and root exudates. When grown in soil, no differences between high and low isolines were found. When grown in hydroponics, no differences in one pair (W9261-BG) were found. In …

Causes And Consequences Of Roost Switching By The Bat Myotis Formosus (V Espertilionidae), Ying-Yi Ho

Digitized Theses

Group living is widespread among animals. Theory predicts that animals should aggregate if the benefits associated with group living outweigh the costs. Benefits associated with group living could arise passively (e.g. aggregate independently to exploit a patchily distributed resource) or actively (e.g. cooperation). Some forest-dwelling bat species switch roosts frequently, but maintain an association among specific individuals, and therefore are fission-fusion societies, the temporary splitting of colonies into several subgroups. Normally, movements between alternative roosts are costly. Fission-fusion societies might overcome the costs by providing benefits associated with large subgroup size or cooperation. In addition, sociality could influence the movements …

A Proteomic Study Of Soybean Seed Coats (Glycine Max), M Carmen Romero

Digitized Theses

The seed coat arises from maternal integuments and its main role is the protection of the developing embryo. At maturity the soybean seed coat is composed mainly of dead cells that impart protection, enable germination and enhance dispersal. Soybean seed coat is an agricultural-by product that is currently under utilized, although some reports have found diverse applications that are currently explored. Using gel-based pre fractionation of proteins followed by electro spray ionization tandem mass spectrometry, a comprehensive proteomic database of physiologically mature soybean seed coats was created. Around 150,000 spectral was acquired and used to challenge current protein databases. The …

Biochemical Characterization Of Cj 1123 C, A Putative Acetyltransferase & Cj 1319, A Putative C6 Dehydratase From Campylobacter Jejuni., Melinda Demendi

Digitized Theses

Glycoproteins are important for the virulence of Campylobacter jejuni. The enzymes involved in protein glycosylation could provide new therapeutic targets. Two such proteins are Cjll23c, a putative acetyltransferase and Cj 1319, a putative GDP-mannose dehydratase encoded by the N- and O-linked protein glycosylation loci in C. jejuni, respectively. We show that Cjll23c is responsible for the synthesis of UDP- diacetamidobacillosamine. We also show that Cj 1123c can N-acetylate the O- glycosylation pathway intermediate, UDP-4-amino-4,6-dideoxy-AltNAc, accommodate different acyl donors and O-acetylate UDP-GlcNAc, thereby generating novel sugars. We demonstrate that Cj 1319 converts GDP-mannose with low conversion efficiency, suggesting that it is …

Change In Availability And Nutritional Quality Of Postharvest Waste Corn On Waterfowl Staging Areas Near Long Point, Ontario, Edward Sydney Barney

Digitized Theses

Increase in harvester efficiency has raised concern that there has been a decrease in the quantity of waste corn available for waterfowl staging in northern areas. I conducted this study to evaluate seasonal changes in waste corn availability and nutritional quality, as well as field use by waterfowl near Long Point, Ontario. I found significant decreases in both waste corn density and nutritional quality between fall (initial) and spring (final) sampling periods. Waterfowl use of fields was not related to initial waste corn abundance; birds used fields based on physical characteristics. Currently, waste corn densities are potentially limiting to waterfowl …

Characterization Of A Mutant Of Chlamydomonas Reinhardtii That Is Deficient In The Molybdenum Cofactor, Daniel R. Fingrut

Digitized Theses

Chlamydomonas reinhardtii strain Dark Blue 6 (DB6) was isolated following random insertional mutagenesis, due to its inability to assimilate nitrate. DB6 lacks terminal nitrate reductase activity and xanthine dehydrogenase activity, indicating that it is deficient in the molybdenum cofactor (Moco) required for those two enzymes. The inability of DB6 to grow on a nitrate medium is partially rescued when it is cultured in a medium containing high concentrations of molybdate. This distinct attribute, termed molybdate repair, is typically associated with mutants defective in molybdate transport or the insertion of molybdenum into the Moco pterin precursor. The molybdenum content in DB6 …

Neuronal Nicotinic Acetylcholine Receptors And Alcohol Preference In Mice: Analyses Of Brain Gene Expression And Co-Segregation Studies, Melissa Nicole Symons

Digitized Theses

Attempts to discover the genetic determinants of alcohol and nicotine addiction have been underway for many years. A common site of action for both nicotine and alcohol effects are neuronal nicotinic acetylcholine receptors (nAChR). This thesis deals with the molecular analysis of four nAChR subunits {Chrna4, Chrnb2, Chma5, and Chrna7) and their relationship with alcohol preference (AP) in mice. The alcohol- preferring C57BL∕6J (B6) and alcohol-avoiding DBA∕2J (D2) strains of mice provide a well established genetic model for the study of AP. Semi-quantitative RT-PCR was used to assess πAChR gene expression in the brains of B6 and D2 mice with …

Gamma-Ray Oxidative Labelling Of Proteins Studied By Esi-Ms, Xin Tong

Digitized Theses

Protein structure, folding and conformational dynamics are critical to understanding biological processes and biochemical reactions. In this work, electrospray ionization mass spectrometry (ESI-MS) combined with a γ-ray-mediated covalent labelling method is used to probe the structure of proteins. ∙OH radicals generated by γ- rays react with solvent-exposed amino acid side chains, which leads to multiple +16 Da shifts in the mass distribution of the protein. This thesis explores the relationship between oxidative labelling and protein concentration, and it investigates how changes in protein conformation affect the overall oxidation level. Using myoglobin as model system, it is demonstrated that the reactions …

The Physiological Ecology Of Coastal Flagellates: A Comparison Among Eutreptiella Gymnastica, Eutreptietta Sp. Strain Jdf-E1, Heterosigma Akashiwo And Chattonella Subsalsa, Kathryn Elizabeth Dickinson

Digitized Theses

Flagellate blooms influenced by anthropogenic contamination of coastal waters often are composed of Eutreptiella gymnastica, Eutreptiella sp. strain JDF-E1, Heterosigma akashiwo and Chattonella subsalsa. This study compared the physiological characteristics of these coastal water flagellates in an effort to explain bloom formation of one strain over another. Physiological differences were assessed in vitro by monitoring growth responses to different forms of nitrogen, and vitamins, and varying levels of light, iron limitation, and copper. This study demonstrated that H. akashiwo may be an r- selected bloom strain controlled by high nutrient levels. Eutreptiella may form secondary blooms due to their efficiency …

Trafficking And Secretion Of Il-10 Fusions In Tobacco Bright Yellow 2 Cell Suspension Cultures, Adil Ahmad

Digitized Theses

The accumulating body of research over the past two decades suggests that plant cell culture is an economically viable system for the production of protein based drugs. In an effort to investigate alternate routes of protein accumulation, interleukin-10 directed by its native signal peptide was fused to various tags including green fluorescent protein, Strepll and elastin-like polypeptide for the purpose of secretion into a culture medium. Our data suggest that media supplemented with several protein stabilizing agents enhanced the accumulation of secreted interleukin-10. It was also noted that the passage of IL-10 fusions through the cell wall into the extracellular …

Treatment Of Wastewater By A Liquid-Solid Circulating Fluidized Bed Bioreactor: Biological Nutrient Removal, Mohammad N. Islam

Digitized Theses

The performance of a Liquid-Solid Circulating Fluidized Bed (LSCFB) Bioreactor for treatment of wastewater with anoxic and aerobic beds and lava rock as biofilm carrier media was used to investigate the impact of the carbon to nitrogen (COD∕N) ratio on the process performance, with particular focus on total nitrogen removal. Three different municipal wastewaters with COD/N ratios of 10:1, 6:1 and 4:1 were tested at an empty bed contact time of 0.82 h. It was found that 90% of influent organic matter was removed throughout the study with 58% removal in the anoxic column at COD/N ratio of 4:1. Total …

Tissue Engineering The Aortic Valve Spongiosa: Assessing The Ability Of Matrigel, Radial Artery Cells And Small Intestinal Submucosa To Form A Spongiosa-Like Layer, Jordan R. Eldred

Digitized Theses

A demand exists to bioengineer an aortic valve replacement in order to overcome the obstacles associated with current valve replacements. Tissue engineering may provide an alternative living valve replacement which demonstrates growth and repair capabilities. The aortic valve contains three functionally and structurally unique layers - the fibrosa, the spongiosa and the ventricularis. The middle spongiosa layer consists mainly of glycosaminoglycans (GAGs), which absorb shock and resist compression forces between the two outer layers of the valve. In order to construct a spongiosa-like layer, Matrigel-cell-scaffold-composites (MCSCs) were assembled by applying a mixture of Matrigel, porcine radial artery cells and endothelial …

Towards The Identification Of A Putative Type Iπ-Like Secretion System Chaperone, Hp1382, And Putative Type-Iii Like Secreted Glycoproteins, Hp0235 And Hp1563, In Helicobacter Pylori, Jaspreet Chahal

Digitized Theses

Putative type III secretion system (TTSS)-Iike proteins were identified in silica in H. pylori. These include two cargo proteins, HP0235 and HP1563 (TsaA) and one chaperone, HP1382. The cargo proteins may be secreted via the H. pylori flagellum in a TTSS-like manner. Two experimental approaches were implemented to identify interacting partners of the TTSS-like proteins. First, HP0235 and HP13 82 were TAP- tagged and introduced into H. pylori. HP0235 was co-purified with its associating partners by IgG affinity chromatography, but low protein expression and recovery prevented downstream analyses. Expression of HP1382 was not inducible by any condition known to induce …

The Effect Of Frequency Compression Signal Processing On Perceived Sound Quality Ratings In Normal Hearing And Hearing Impaired Subjects, Andreas S.W. Seelisch

Digitized Theses

Hearing loss is common in today’s society, it is estimated that 1 in 10 Canadians has hearing loss with estimates rising to 8 in 10 for geriatric populations. Hearing loss is known to have dramatic effects on the individuals that extend well beyond communicative issues. Psychological consequences range from depression exhaustion. Children suffer additional problems such as failure to acquire language and poor academic performance. While hearing aids remain the primary avenue by which hearing loss is treated, numerous individuals with hearing loss in the high frequencies get very little benefit from conventional amplification due to biological and technological limitations. …

Surface Functionalized Iron Oxide Nanoparticles For Magnetic Resonance Imaging, Amanda L. Martin

Digitized Theses

Magnetic resonance imaging (MRI) is a powerful tool for the diagnosis of disease and the study of biological processes. Superparamagnetic iron oxide nanoparticles (SPIO) are effective contrast agents and provide high sensitivity in MRI. Recent research has demonstrated that single SPIO labeled cells can be detected in vivo by MRI, illustrating the promise of this contrast agent. A novel conjugation method was developed using a click cycloaddition between azide functionalized nanoparticles and target molecules containing alkynes. To increase the cell loading of SPIO, a guanidine terminated polyester dendron was conjugated to SPIO and was found to have remarkable uptake into …

The Effect Of Frequency Compression Signal Processing On Perceived Sound Quality Ratings In Normal Hearing And Hearing Impaired Subjects, Andreas S.W. Seelisch

Digitized Theses

Hearing loss is common in today’s society, it is estimated that 1 in 10 Canadians has hearing loss with estimates rising to 8 in 10 for geriatric populations. Hearing loss is known to have dramatic effects on the individuals that extend well beyond communicative issues. Psychological consequences range from depression exhaustion. Children suffer additional problems such as failure to acquire language and poor academic performance. While hearing aids remain the primary avenue by which hearing loss is treated, numerous individuals with hearing loss in the high frequencies get very little benefit from conventional amplification due to biological and technological limitations. …

Single Nucleotide Polymorphsim And Methylation Analysis Of Htr1b And Notch4 In Schizophrenia And Affective Disorder, Patrick Peter Mcdonald

Digitized Theses

Schizophrenia and affective disorder are common, related mental disorders. They are episodic or chronic in nature and first present between adolescence and adulthood. The symptoms of the two diseases are variable, overlap and include mania, depression, delusions, hallucinations and disorganization of speech and behaviour. Treatments for both diseases include antidepressants and antipsychotics, but there are no cures. Both are thought to be neurodevelopmental in nature and family studies have demonstrated strong genetic components. The search for these genetic components has identified a number of genomic regions and candidate genes but no causal gene. Ofthese genomic regions, both the long and …

Canada’S Biotechnology Strategy: Struggles On The Knowledge Commons, Wilhelm C. Peekhaus

Digitized Theses

This research critically analyses a number of the social, economic,

environmental, and informational questions that attach to biotechnology in the context of Canada’s Biotechnology Strategy. A neo-Marxist biopolitical framework that draws on a number of theoretical elements from autonomist Marxism informs the conceptual scheme. Much like Marx’s methodological orientation based on the perspective of the working class rooted in its own historical activity, contemporary efforts at understanding and situating the current conjuncture of capitalist social relations can be advanced through research into the genealogy of social and political opposition movements. By apprehending these emerging subjectivities we might begin developing a …

Cerebral Hemodynamic Disturbances In Motor Neuron Disease, Matthew J. Murphy

Digitized Theses

An association between motor neuron disease (MND) and dementia was first realized in the late 1800s, yet substantiating research and a description of dementia as part of the clinical syndrome would not appear until the 1990s. In the last two decades, medical imaging has investigated cerebral blood flow changes in the motor and non­ motor cortex to correlate with motor dysfunction and clinical dementia, respectively. The aim of this thesis is to describe early cerebral hemodynamic disturbances with the goal to determine a marker for cognitive decline in MND.

Chapter 2 describes the relationship between changes in cerebral hemodynamics and …

Causes And Consequences Of Roost Switching By The Bat Myotis Formosus (Vespertilionidae)), Ying-Yi Ho

Digitized Theses

Group living is widespread among animals. Theory predicts that animals should aggregateifthebenefitsassociatedwithgrouplivingoutweighthecosts. Benefits associated with group living could arise passively (e.g. aggregate independently to exploit a patchily distributed resource) or actively (e.g. cooperation).

Some forest-dwelling bat species switch roosts frequently, but maintain an association among specific individuals, and therefore are fission-fusion societies, the temporary splitting ofcolonies into several subgroups. Normally, movements between alternative roosts are costly. Fission-fusion societies might overcome the costs by providingbenefitsassociatedwithlargesubgroupsizeorcooperation. Inaddition, sociality could influence the movements of individuals within and between social groups andaffectthegeneflow. However,ourunderstandingabouttheunderlyingcausesand effects of fission-fusion behaviour is still lacking.

I used both direct …

Development, Testing, And Application Of Stressor Gradients In Rural, Headwater Streams In Southwestern Ontario, Adam G. Yates

Digitized Theses

Effective biological monitoring requires a conceptual model of how human activity varies and how this activity affects resident biota. This model can then be used to generate appropriate hypotheses and study designs in response to bioassessment needs. Stressor gradients have the potential to improve this process, but questions about the development and effectiveness of stressor gradients must be addressed before they can be widely applied to biological monitoring.

With the aim of developing the most effective and efficient stressor gradient, four gradients were calculated from stressor information differing in level of detail and spatial explicitness for 479 rural, headwater basins. …

Rna Expression Of Six Arogenate Dehydratase Genes In Arabidopsis Thaliana, Rebecca Lynne Hood

Digitized Theses

Six AROGENA TE DEHYDRA TASE (ADT) genes encode enzymes involved in phenylalanine synthesis in Arabidopsis thaliana. The tissue-specific RNA expression patterns of ADTs and their response to heat and cold stress were studied. Tissue-specific analyses indicated that ADTs are constitutively expressed at differing levels and that expression of particular ADTs is predominant in some tissues. Expression of all ADTs increased in response to cold treatment, either with a single (ADT1, ADT3, and ADT6), or bimodal (ADT2, ADT4, and ADT5) rise in expression. Expression returned to basal levels for all ADTs following a 24 h post-stress recovery. In response to heat …

Root Colonization Of Burkholderia Phytoβrmans Strain Psjn And Its Relation To The Bacterial Plant Growth Promoting Ability, Li Xu

Digitized Theses

Burkholderia phytofιrmans strain PsJN has been demonstrated to consistently promote plant growth under tissue culture conditions. The response of inoculated plants, however, can be highly variable under greenhouse or field conditions. In this study I set out to systematically examine how bacterial root colonization affects plant growth promotion. To achieve that goal, the regular potato explant bioassay was modified for better accuracy and efficiency and a genetically modified strain of PsJN was created with the gfp gene integrated into the genome for quantitative detection. Using competitions by a non-plant-growth-promoting mutant or a non-related bacterium Delftia acidovorans, PsJN’s population was manipulated …

Selenium Uptake And Effects In Greater Scaup (Aythya Maπla) Wintering On Western Lake Ontario, Lindsay L. Ware

Digitized Theses

One hypothesis for the decline of the North American greater (Aythya marila) and lesser (A. affinis) scaup population is that contaminant loads acquired on wintering or staging areas are causing lethal or sub-lethal health effects, including impaired reproduction. I investigated whether the health of greater scaup wintering on Hamilton Harbour, Lake Ontario, is affected by elevated selenium (Se) concentrations. Greater scaup were analyzed for Se and other contaminants, and assessed for health and body condition. No relationship between Se concentration and fat or protein level was detected. Furthermore, no relationship between Se concentration and symptoms of Se toxicosis, including increased …

Shifts In The Magnitude And Partitioning Of Atmospheric Versus Aquatic Carbon Export In Response To Changing Climatic Conditions, Andrew P. Rams

Digitized Theses

The average annual temperature measured at the Turkey Lakes Watershed has increased significantly (p=0.004) over the past 27 years. The effects of increasing annual temperatures and changing precipitation patterns on the export of carbon (C) from forests within this region are not fully understood. The aim of this thesis was to determine whether changes in meteorological conditions have caused changes in the magnitude and partitioning of atmospheric vs. aquatic C export form a forested catchment in the Turkey Lakes Watershed during the growing seasons (May 1 to October 31) over a five year period (2003 to 2007). Soil samples were …

Regulation Of The Alternative Oxidase In Chlamydomonas Reinhardtii By Nitrogen Source, Shanmugasundaram Pakkiriswami

Digitized Theses

The current study investigated the influence of photosynthesis on the nitratedependent induction of AOX by using C. reinhardtii. Measurement of light response curves for oxygen evolution, assessment of changes in photochemistry of PSII by chlorophyll a fluorescence technique, measurement of respiration, measurement of de-epoxidation state, measurement of total ATP content and western blot analysis of AOX were performed. Flourescence parameters like excitation pressure and non-photochemical quenching were decreased during the nitrate shift. Nitrate shifted cells showed higher alternative pathway capacity than the ammonium grown one, but no significant change in overall respiration occurred. The kinetics and extent of AOX accumulation …

Rain Induced Bursts Of Denitrification Activity Account For Differences In Dissolved Nitrogen Export From Forested Catchments, Nora J. Casson

Digitized Theses

This study sought to explain differences in dissolved nitrogen (N) export between catchments in the Turkey Lakes Watershed. Neighbouring catchments c35 and c38 have similar N inputs, but a discrepancy in dissolved N export. It was hypothesized that gaseous N export from wet soils accounted for this discrepancy as c35 contains few isolated wet soils, whereas c38 contains many connected wet soils. To test this hypothesis, N2O efflux from soils was measured during the growing season in 2006 and 2007. Minimal N2O efflux (< 1 g N ha1 day1) was observed on days without rain. However, on days with rain, N2O efflux was observed, with a linear increase in the rate of N2O efflux from wet soils of 0.016 g N ha1 day1 (r2=0.60, p<0.001) per millimetre of rain. Intensive monitoring of the wetland soil profile suggested that rain delivers water to the surface layers of the wetland creating an oxygen poor environment where accumulated NO3 is transformed to N2O then N2. The discrepancy in dissolved N export between c35 and c38 was explained when N2O and associated N2 efflux (based on a ratio of 10N2:1N20) from the wet soils in c38 were considered. This study suggests that rain can produce substantial bursts of N2O and N2 from forest soils and that failure to account for gaseous N export may lead to an underestimation of N export from forested catchments.

Plants As A Novel Bioreactor To Produce Human Therapeutic Proteins For The Treatment Of Type 1 Diabetes, Xiaofeng Wang

Digitized Theses

Using transgenic plants to express and deliver autoantigens represents an attractive strategy to induce oral tolerance to treat autoimmune diseases. Several challenges remain if this approach is applied to treat diabetes. This thesis aims to address these challenges through an investigation into: 1) the use of transgenic plants to express human preproinsulin, and an adjuvant-autoantigen fusion protein comprising human preproinsulin fused to mIL-4 for oral tolerance induction; 2) the use of transgenic plants to express hGAD67 to induce oral tolerance; 3) the exploration of chloroplasts of the alga Chlamydomonas reinhardtii as a novel expression platform for high-level, industrial scale production …

Purification And Characterization Of Extracellular Glycosidases From The Ginseng Root Pathogen, Pythium Irregulare, M. Andreea Neculai

Digitized Theses

Three ginsenoside-deglycosylating enzymes have been purified 13- to 25-fold, from Pythium irregulare culture filtrates, by a four-step purification protocol. The three glycosidases are relatively high molecular weight (a homodimer of 78 kDa subunits and two monomeric enzymes of 57 and 61 kDa), acidic proteins, sharing these properties with a series of other saponin-glycosidases. They were induced in cultures grown in the presence of ginsenosides and they have apparently, different glycosidic activities (1→6 versus 1→2). Primary sequence analysis identified them as glycosidases, but did not relate them to other saponin-deglycosylating enzymes. While no definite conclusions can be drawn regarding the involvement …