Graduate Theses & Dissertations

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Bio-based Polymers from Epoxidized Vegetable Oils Modified by Metathesis
The epoxides of oligomeric self-metathesized soybean oil (MSBO) and cross-metathesized palm oil (PMTAG) and canola oil (CMTAG) containing terminal double bonds were used to produce nonisocyanate polyurethanes (NIPUs) as well as anhydride, amine and thiol-cured epoxies. The synthesized NIPUs displayed metal adhesive properties for CMTAG and MSBO with MSBO being favoured probably due to its plasticizing nature as opposed to CMTAG. The relationship was reversed for the anhydride curing reaction where it was found that CMTAG, due to its lower degree of plasticizing content from the reduced dangling chains, produced higher tensile strengths than MSBO. Both MSBO and CMTAG led to fully cured amine and thiol products that were sticky gels, which prevented physical analyzses of their expected solidified products. PMTAG, due to its low number of reactive groups, was not suitable for the synthesis of these polymers. Author Keywords: Amine-cured epoxy, Anhydride-cured epoxy, Metathesis, Nonisocyanate Polyurethanes, Thiol-cured epoxy
Biodiversity patterns along a forest time series in a remediated industrial landscape
Sudbury, Ontario is an epicenter of research on industrially degraded landscapes. Regreening efforts over the past 40 years have changed the landscape, leading to an increase in forest cover in the “barrens”, that once covered more than 100,000 ha. This study characterized changes in plant and insect composition using a space for time approach in the pine plantations. A total of 25 treated sites were sampled and soil characteristics, understory plants and insect communities were assessed. All sites were contaminated with copper and nickel, but the metals had little influence on biodiversity. Vegetation diversity metrics were more strongly correlated with the pH of the organic soil horizons, while the insect community shows little response to site characteristics, and rather vegetation cover. Plant composition changes are similar to those in pine stands undergoing natural recovery and as liming effects fade there may be a decline in insect community richness. Author Keywords: Biodiversity, Heavy Metals, Mining, Remediation
Biology and Management of Stratiotes Aloides in the Trent River, Ontario
Invasive aquatic plants can create negative ecological, economic and social impacts when they displace local vegetation, interfere with shipping and navigation and inhibit water-based recreational activities. In 2008, the first North American occurrence of the invasive plant Stratiotes aloides (Water soldier) was identified in the Trent River, Ontario. This research measured offset photosynthesis and turion germination to determine the light compensation point (5.2-5.4m) and maximum depth of colonization (4-6m) for S. aloides propagules using in situ incubations and controlled growth experiments. The effects of spring and fall chemical (Diquat) and physical (hand raking) treatments on S. aloides biomass, local macrophyte recovery and community dynamics in the Trent River were also measured. The target of a 75% minimum reduction in S. aloides biomass was not attained using any of the treatment methods and no perceivable recovery of the local plant community was observed. Significant S. aloides regrowth was recorded for both treatment methods regardless of application timing. Author Keywords: herbicide, invasive species, macrophyte, photosynthesis, propagule
Bioremoval of copper and nickel on living and non-living Eugelna gracilis
This study assesses the ability of a unicellular protist, Euglena gracilis, to remove Cu and Ni from solution in mono- and bi-metallic systems. Living Euglena cells and non-living Euglena biomass were examined for their capacity to sorb metal ions. Adsorption isotherms were used in batch systems to describe the kinetic and equilibrium characteristics of metal removal. In living systems results indicate that the sorption reaction occurs quickly (<30 min) in both Cu (II) and Ni (II) mono-metallic systems and adsorption follows a pseudo-second order kinetics model for both metals. Sorption capacity and intensity was greater for Cu than Ni (p < 0.05) and were described by the Freundlich model. In bi-metallic systems sorption of both metals appears equivalent. In non-living systems sorption occurred quickly (10-30 min) and both Cu and Ni equilibrium uptake increased with a concurrent increase of initial metal concentrations. The pseudo-first-order model was applied to the kinetic data and the Langmuir and Freundlich models effectively described single-metal systems. The biosorption capacity of Cu (II) and) was 3x times greater than that of Ni (II). Sorption of one metal in the presence of relatively high concentrations of the other metal was supressed. Generally, it was found that living Euglena remove Cu and Ni more efficiently than non-living Euglena biomass in both mono- and bi-metallic systems. It is anticipated that this work should contribute to the identification of baseline uptake parameters and capacities for Cu and Ni by Euglena as well as to the increasing amount of research investigating sustainable bioremediation. Author Keywords: accumulation, biosorption, Cu, Euglena gracilis, kinetics, Ni
Biosynthesis and impact of cytokinins on growth of the oyster mushroom, Pleurotus ostreatus
The oyster mushroom, Pleurotus ostreatus, is one of the most widely cultivated edible basidiomycetes. It has gained increased attention for its economic, environmental, and medicinal properties. While a lot is known about cytokinins (CKs) and their actions at the molecular and cellular levels in plants, much less is known about the function of CKs in other kingdoms. Cytokinins, which have been detected in several fungal species, play a role in pathogenic attack against plants or during plant growth promotion by plant beneficial microbes; however, the role of CKs in fungal physiology, separate from plant associations remains largely unknown. This thesis focuses on the occurrence of fungal-derived CKs in P. ostreatus when grown in vitro as submerged or aerial mycelium. Cytokinin profiling by UHPLC-HRMS/MS revealed that P. ostreatus produces CKs and that the tRNA degradation pathway is the main source of these molecules. CK dynamics within fungal growth supported previous evidence, which suggested that tRNA degradation products have a role in the physiological development of fungi for which CKs act as fungal growth regulators. A second component of the thesis demonstrated that P. ostreatus responds to exogenous applications of aromatic and isoprenoid CKs and their effects were dependent on the dose and CK type. N6-Benzyladenine (BAP), Kinetin (KIN), N6-isopentenyladenine (iP), and trans-zeatin (tZ) bioassays revealed hormone-type responses (hormesis: biphasic response). At low doses, mycelium growth could be stimulated, whereas, at high doses only inhibitory effects were observed. This stimulation/inhibition was observed whether the measured response was an increase/decrease of aerial mycelium colony diameter, biomass accumulation or a change in mycelium morphology as compared to the controls. Results indicated there is potential to alter mycelium growth and development of P. ostreatus; thus, CKs may play the role of a “mycohormone” and may be specifically helpful for medicinal fungi by increasing growth and efficiency to produce many biologically active substances with valuable medical and environmental applications. Author Keywords: cytokinins, fungal-derived CKs, hormesis, mycelium, mycohormone, Pleurotus ostreatus
Branding of the Prime Minister
From 1949-1957, Prime Minister Louis St. Laurent was the face of the Liberal Party. Party branding was wholly devoted to his friendly, ‘Uncle Louis’ brand image. St. Laurent’s image was manipulated and manufactured without public preconception, establishing the modern tactics of personal branding still used by his successors. This thesis studies the elections of 1949, 1953, and 1957, analysing photos, advertisements, speeches, archival documents, memoirs, newspapers, and other sources to show the development of Liberal branding strategy. It employs political scientist Margaret Scammell’s conceptualization of brand theory, showing how marketers used emotional brand differentiators and rational substantive performance indicators to sell ‘Uncle Louis’ to Canadians. The Liberals used St. Laurent and branding tactics to win two massive majorities in 1949 and 1953, and the Diefenbaker Tories used those same tactics to defeat them in 1957. ‘Uncle Louis’ proved the effectiveness of personal branding and leader-centered campaigns in Canadian politics. Author Keywords: Brand Theory, Canadian Politics, Elections, Liberal Party of Canada, Louis St. Laurent, Political Marketing
Breeding Phenology and Migration Habits of Whimbrel (Numenius phaeopus) in the Hudson Bay Lowlands, Canada
Understanding breeding and migration habits of Whimbrel (Numenius phaeopus) in the Hudson Bay Lowlands is important for the conservation of this population. I monitored Whimbrel at two breeding sites: the Churchill region of Manitoba and Burntpoint, Ontario. Annual average nest initiation timing was highly variable and successful nests were initiated significantly earlier than those that failed. Although nests were initiated significantly earlier at Burntpoint than Churchill, annual nest success quantified in program R MARK was similar across sites. Observed nest success rates were lower than historical records and most failure was due to predation. Annual nest survival varied widely and I used a generalized linear model to relate annual nest survival to annual average weather conditions. I observed weak relationships between annual nest survival and weather conditions in the northbound staging grounds. I tracked post-breeding migratory movements using the MOTUS radio telemetry system and observed consistent use of the mid-Atlantic coast of the United States during migration, especially among birds emerging from Churchill. In Burntpoint, I observed more variability in post-breeding migratory trajectories and significantly earlier post-breeding departure as compared to Churchill. The results of my study suggest differences in breeding and migration habits exist across nearby breeding populations, indicating that there is a need for population-specific conservation approaches for this declining species. Author Keywords: Migration, Movement Ecology, Nesting Ecology, Nest Success, Shorebird conservation, Whimbrel
Building Individuals, Building the Economy
This thesis explores the neoliberal governmentality approach to education for Northern economic development that was prevalent from 2006 to 2015, during Stephen Harper’s period as Prime Minister of Canada. Using a grounded theory approach, this thesis identifies three themes – Indigenous integration, education, and employment for labour force/ economic development – to direct an analysis on programs and funding supported by the Canadian Northern Economic Development Agency, Employment and Social Development Canada, and Indigenous and Northern Affairs Canada. This examination suggests that Federal programming and funding encouraged neoliberal governmentality approaches to Northern development and education. Specifically, the former Government interest in developing an Indigenous work force to serve labour market needs is brought to light. Author Keywords: Economic Development, Indigenous Education, Labour Force Development, Neoliberalism, Territorial North
Building social connections
This thesis evaluates a multi-stakeholder participatory planning initiative, NeighbourPLAN, in Peterborough, Ontario, and the role of the third-party broker, GreenUP, in establishing connections and networks of capacity between marginalized members of the community and contributing organizations, city, and experts. Participatory approaches to engage residents disenfranchised by traditional planning processes are believed to challenge the status quo perpetuated by top-down decision-making. I worked within two neighbourhoods involved in NeighbourPLAN to determine whether the collaborative work and brokering between stakeholders would foster increased connectedness that could exist independently and last beyond the project's timeline. The findings from this evaluation determine that, from the residents' perspectives, while the presence of the other stakeholders in these participatory planning events was valuable, there was not enough affective time to create long-lasting connections. Partners that developed relationships marked with trust and mutual benefit provide a helpful blueprint showing how serious commitment and consistency can build sustainable and meaningful connections. I conclude with a set of recommendations to enhance the connection building between diverse stakeholders and marginalized communities within NeighbourPLAN, highlighting the promising potential of arts-based and storytelling methods. Author Keywords: arts-based methods, community engagement, Participatory action research (PAR), participatory planning, photovoice, social connectedness
Building wind energy landscapes
This thesis project explores landowner experiences of wind energy development through an inductive qualitative case study in Huron County, Ontario. The research included in-depth interviews with landowners focused on landscape and community change, participant observation of Environmental Review Tribunals (ERT), the gathering of participant photos, as well as relevant government and industry documents and media reports. The iterative data gathering and analysis were supported by my observations and reflections while living in affected communities and talking to participants. The study demonstrates how the health debate over wind can inform divisions between neighbours, that local politics have been given a token role as a place for resistance to wind energy development that fails to meaningfully influence projects, and that appeals are legalistic and do not provide an outlet, or place for appellants to be heard. Furthermore, the felt experience of tight knit and fragile communities were disrupted through land leases, as well as changes to the landscape. These disruptions impacted connections to, and associations with place, and are shown to have had negative emotional and physical impacts on some individuals. Supporters of wind development tied their mostly positive views of landscape change to a sense of disruption generally throughout the community. Insights from the research lead to a set of suggested actions that might improve the current situation at the levels of provincial policy, planning, local governance and industry practice. Keywords: wind energy policy, planning, landscape, Ontario, rural communities Author Keywords: Affect, landscape, Ontario, planning, Rural communities, Wind energy policy
Bundles and Bloodletting
This thesis addresses the inclusion of women within Classic Maya works of art, consisting of, for this purpose, private-consumption ceramic vessels and large scale public monuments. Through the use of Feminist and Gender Theory, Performance Theory, and Iconographic Theory, the roles of women in iconographically depicted ceremonial performance is assessed. A Microsoft Access database was constructed in order to look at various aspects of female depiction, including but not limited to, bodily action, costume, and paraphernalia. The context, individual action, and associated paraphernalia of women performing numerous roles were analyzed, in which women were found to participate in many of the same roles as men, although there are some roles from which either men or women are excluded, and certain paraphernalia items with which women are not associated. Author Keywords: Archaeology, Feminism, Gender Theory, Iconography, Maya Art, Performance Theory
CO2 dynamics of tundra ponds in the low-Arctic Northwest Territories, Canada
Extensive research has gone into measuring changes to the carbon storage capacity of Arctic terrestrial environments as well as large water bodies in order to determine a carbon budget for many regions across the Arctic. Inland Arctic waters such as small lakes and ponds are often excluded from these carbon budgets, however a handful of studies have demonstrated that they can often be significant sources of carbon to the atmosphere. This study investigated the CO2 cycling of tundra ponds in the Daring Lake area, Northwest Territories, Canada (64°52'N, 111°35'W), to determine the role ponds have in the local carbon cycle. Floating chambers, nondispersive infrared (NDIR) sensors and headspace samples were used to estimate carbon fluxes from four selected local ponds. Multiple environmental, chemical and meteorological parameters were also monitored for the duration of the study, which took place during the snow free season of 2013. Average CO2 emissions for the two-month growing season ranged from approximately -0.0035 g CO2-C m-2 d-1 to 0.12 g CO2-C m-2 d-1. The losses of CO2 from the water bodies in the Daring Lake area were approximately 2-7% of the CO2 uptake over vegetated terrestrial tundra during the same two-month period. Results from this study indicated that the production of CO2 in tundra ponds was positively influenced by both increases in air temperature, and the delivery of carbon from their catchments. The relationship found between temperature and carbon emissions suggests that warming Arctic temperatures have the potential to increase carbon emissions from ponds in the future. The findings in this study did not include ebullition gas emissions nor plant mediated transport, therefore these findings are likely underestimates of the total carbon emissions from water bodies in the Daring Lake area. This study emphasizes the need for more research on inland waters in order to improve our understanding of the total impact these waters may have on the Arctic's atmospheric CO2 concentrations now and in the future. Author Keywords: Arctic, Arctic Ponds, Carbon dioxide, Carbon Fluxes, Climate Change, NDIR sensor

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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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