Graduate Theses & Dissertations

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Assessing the population genetic structure of the endangered Cucumber tree (Magnolia acuminata) in southwestern Ontario using nuclear and chloroplast genetic markers.
Magnolia acuminata (Cucumber tree) is the only native Magnolia in Canada, where it is both federally and provincially listed as endangered.Magnolia acuminata in Canada can be found inhabiting pockets of Carolinian forest within Norfolk and Niagara regions of southwestern Ontario. Using a combination of nuclear and chloroplast markers, this study assessed the genetic diversity and differentiation of M. acuminata in Canada, compared to samples from the core distribution of this species across the United States. Analyses revealed evidence of barriers to dispersal and gene flow among Ontario populations, although genetic diversity remains high and is in fact comparable to levels of diversity estimated across the much broader range of M. acuminata in the USA. When examining temporal differences in genetic diversity, our study found that seedlings were far fewer than mature trees in Ontario, and in one site in particular, diversity was lower in seedlings than that of the adult trees. This study raises concern regarding the future viability of M. acuminata in Ontario, and conservation managers should factor in the need to maintain genetic diversity in young trees for the long-term sustainability of M. acuminata in Ontario. Author Keywords: conservation genetics, cpDNA, forest fragmentation, Magnolia acuminata, microsatellites, population genetic structure
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
Near-Hand Effects and Recruitment of Visual-Tactile Bimodal Cells
Near-hand benefits are seen when individuals are able to process targets more quickly, accurately, and with greater precision when a hand is placed near, rather than far from a target. One possibility is that near-hand stimuli recruit visual-tactile bimodal cells. Research reports that placing a hand near a target delayed immediate saccade onset and speeded delayed saccade onset. Study 1 examined saccade onset to targets appearing near a real hand, a realistic fake hand, or a non-hand visual cue. Immediate saccades were facilitated and delayed saccades were slowed with a real hand in the display, in comparison to a fake hand and no-hand. To establish the link between near-hand effects and bimodal cells, Study 2 used repetitive transcranial magnetic stimulation (rTMS) to depress cortical activity in PMd. RTMS did not induce a reversal of interference induced by near-hand, congruent targets. However, a reversal of the hand effect was found in the stimulation group; a real hand in the display may delay immediate saccades and improve delayed saccades post-stimulation. This finding may double dissociate the effect of the real hand from the fake hand and may be inconsistent with the hypothesis that the hand is attracting attention. Author Keywords: multisensory integration, near-hand effects, PMd, premotor cortex, rTMS, visual-tactile bimodal neurons
Models of partitioning, uptake, and toxicity of neutral organic chemicals in fish
Models of partitioning, uptake, and toxicity of neutral organic chemicals in fish Alena Kathryn Davidson Celsie A novel dynamic fugacity model is developed that simulates the uptake of chemicals in fish by respiration as applies in aquatic toxicity tests. A physiologically based toxicokinetic model was developed which calculates the time-course of chemical distribution in four tissue compartments in fish, including metabolic biotransformation in the liver. Toxic endpoints are defined by fugacity reaching a 50% mortality value. The model is tested against empirical data for the uptake of pentachloroethane in rainbow trout and from naphthalene and trichlorobenzene in fathead minnows. The model was able to predict bioconcentration and toxicity within a factor of 2 of empirical data. The sensitivity to partition coefficients of computed whole-body concentration was also investigated. In addition to this model development three methods for predicting partition coefficients were evaluated: lipid-fraction, COSMOtherm estimation, and using Abraham parameters. The lipid fraction method produced accurate tissue-water partitioning values consistently for all tissues tested and is recommended for estimating these values. Results also suggest that quantum chemical methods hold promise for predicting the aquatic toxicity of chemicals based only on molecular structure. Author Keywords: COSMOtherm, fish model, fugacity, Partition coefficient, tissue-water, toxicokinetics
Archaeological Investigation of the North Group at Pacbitun, Belize
This thesis reports on the 2010 excavations of the North Group and Eastern Court at the ancient Lowland Maya site of Pacbitun. It provides a construction history of the architecture and an analysis of associated artifacts, burials, and caches. The archaeological investigations demonstrate that the seven structures (Strs. 34-40) of this restricted access plazuela group were built in the Early Classic period, and renewed in the Late Classic period. Based on analyses of artifacts (ceramics and lithics), skeletal and faunal remains, and intra- and inter-site comparisons, the North Group functioned as a secondary elite domestic residential group. Reconstruction suggests that the inhabitants here were not commoners; instead, the occupants probably were related to the ruling elite of Pacbitun. Some of the evidence includes the central location and elevation of the North Group, the presence of red painted plaster surfacing, a burial with multiple ceramic musical instruments, and multiple dedicatory caches with exotic goods (e.g., marine shell, jadeite, "Charlie Chaplin" figures). Author Keywords: Ancient Maya, ceramic musical instruments, Charlie Chaplin figurines, Pacbitun, North Group, Eastern Court, Belize River Valley, Belize, restrictive access plazuela group, secondary elite
That They Might Sing the Song of the Lamb
This thesis examines Hildegard of Bingen (1098-1179)'s theology of music, using as a starting place her letter to the Prelates of Mainz, which responds to an interdict prohibiting Hildegard's monastery from singing the liturgy. Using the twelfth-century context of female monasticism, liturgy, music theory and ideas about body and soul, the thesis argues that Hildegard considered the sung liturgy essential to monastic formation. Music provided instruction not only by informing the intellect but also by moving the affections to embrace a spiritual good. The experience of beauty as an educational tool reflected the doctrine of the Incarnation. Liturgical music helped nuns because it reminded them their final goal was heaven, helped them overcome sin and facilitated participation in the angelic choirs. Ultimately losing the ability to sing the liturgy was not a minor inconvenience, but the loss of a significant spiritual and educational tool fundamental to achieving union with God. Author Keywords: Hildegard of Bingen, Letter to the Prelates of Mainz, liturgy, monasticism, music
Canadian Refugee Policy
This dissertation is an inquiry into the politics of the frame in Canadian refugee policy. It is focused on "framing," thereby taking up the stance of critical policy studies while pressing the contribution of Donald Schön and Martin Rein in a critical and politically inflected direction. The dissertation unfolds as a political history of Canadian refugee policy that provides a "contextual mapping," relevant to both inquiry and action in regard to the framing of refugees. The main argument is that twentieth- and twenty-first- century refugee policy in Canada is a story of three shifting meta-frames: beginning with humanitarianism (in the inter-War years and the post-World War II period); shifting to neo-humanitarianism (beginning in the late 1970s, in connection with the rise of neoliberalism); then shifting again (beginning in the 1990s) to securitization. The concept of a meta-frame here is analogous to that of a "metacultural frame" in Schön and Rein, but accents political rather than cultural dimensions. This concept is developed in a manner suitable to a political history by illustrating how meta-frames both become stable and change. With humanitarianism, the refugee was typically portrayed in ambivalent terms - both deserving of and entitled to protection, while also posing a burden for the national interest. In the context of neo-humanitarianism, this ambivalence began to wane, and the refugee was more typically portrayed as a potential criminal. With securitization, especially as it has become entrenched and intensified, the refugee has been more typically portrayed as a potential terrorist. The analysis includes a focus on the particular importance of ambivalence and contingency in the politics of the frame. Securitization has become so deeply entrenched since September 11, 2001 that it appears virtually fixed in place. However, it may still become possible in moments of contingency for refugee advocates to destabilize the securitization meta-frame and help shift the framing of refugees into a more hospitable register. Author Keywords: ambivalence, contingency, humanitarianism, neo-humanitarianism, refugees, securitization
Sponsoring Private Schools in an Informal Empire
This thesis analyzes the history of the Inter-American Schools Service (IASS), which ran under the auspices of the American Council on Education beginning in 1943. The program was defined as a private initiative aimed at spreading U.S. democratic values throughout the hemisphere for the mutual benefit of both the United States and Latin America. Yet the program was ultimately one facet of the United States' informal imperialism and a tool for the consolidation of U.S. hegemony, which came at the expense of Latin Americans' pursuit of the very values the IASS was said to facilitate. This theme is explored through a general discussion of cultural policy in the twentieth-century United States as well as the specific history of the IASS program and its relation to U.S. policies of intervention in Guatemala and Bolivia. Author Keywords: American Schools, Cultural Imperialism, Guatemala, Hegemony, Informal Imperialism, Inter-American Schools Service
"Energetics" of Mycenaean Defense Works
This thesis examines the mobilization of labour required for fortification construction during the Late Helladic (LH) period of the Aegean Bronze Age. It adopts an "energetics" approach to architecture, as a framework for systematically calculating the labour costs of construction, and using such costs to infer relative differences in political power among groups and communities through the implied differences in labour control. Accordingly, construction costs were generated for thirty-six LH fortifications, located across seven distinct regional zones of the Greek mainland and Aegean Sea. These values were then compared and evaluated against what is known of the political geographies for each region, to measure the extent to which the mobilization of labour was a function of regional power in Late Bronze Age Greece. These assessments revealed that a wide range of variation existed among the sampled regions in terms of the strength and nature of this connection, underscoring the diversity in labour relations that developed throughout the Aegean during the LH period. The labour costs were also used to suggest specific systems of recruitment that may have been in place for mobilizing workers, and to argue that fortification construction would not have been particularly burdensome or demanding for certain local populations. Author Keywords: Energetics, Fortifications, Late Bronze Age, Monumental Architecture
Holocene Resource Exploitation
This study uses the zooarchaeological record to examine the range of activities represented in Late Archaic period samples excavated from Jacob's Island -1B, in the Trent-Severn Waterway region in Ontario. Radiocarbon dates from sixteen features were used to establish a chronology of site use and occupation. The faunal remains analyzed in this study were recovered from seven dated mortuary features associated with human remains. The results of the faunal analysis suggest that Canis lupus familiaris was the primary species interred at Jacob's Island-1B. Small rodents, specifically Tamias striatus were also found in high abundance and are possibly the result of natural burrowing disturbances. Red ochre staining and low levels of burning were identified. Comparisons with other contemporaneous sites in the region indicate some variation in species composition. It is suggested that Canis lupus familiaris was associated with ritual and mortuary activities at Jacob's Island-1B. Author Keywords: Canis lupus familiaris, Late Archaic Period, Ontario, Ritualsim, Zooarchaeology
Local Immigration Partnerships
Introduced as part of the Canada-Ontario Immigration Agreement, Local Immigration Partnerships (LIPs) mark a fundamental shift in local settlement policy. To address the gap in knowledge about the implications of this policy change, this thesis research features a case study of Durham Region's LIP. Objectives were designed to examine the impact of Durham's LIP by interviewing 52 key-informants within six sectors involved in settlement and integration. Findings indicate an effective application of the LIP policy with participants pointing to the LIP's vital role in bringing Welcome Centres to Durham, increasing the attention and profile of immigration issues and improving governance relations amongst different sectors in settlement and integration. A product of local circumstances, the LIP has engaged in a quasi-advocacy role educating mainstream service providers and institutions on how to respond to a diversifying population. Results contribute to the relatively under-studied but growing knowledge of the LIP policy while demonstrating that the localization of immigration policy under the appropriate terms can be successful. Author Keywords: Governance, Integration, Local Immigration Partnerships, Ontario, Regionalization, Settlement
From Reading to Reality
This thesis explores post-millennial girl fiction, or young adult works published for girls since the turn of the millennium. Writing for girls has been traditionally placed beneath `more serious' literature, within a hierarchal model, while modern works enjoy an iconic status that is the product of cross-media popularity and a wide readership. Criticism has focused on post-millennial girl fiction being unwholesome, poorly written or anti-feminist, examination of the texts reveals personas which girls may use to explore, rebel against and critically examine societal expectations and fears about girlhood. To explore the publishing phenomenon surrounding current girls' fiction I use two sample series: Gossip Girl by Cecily Von Ziegesar and Twilight by Stephanie Meyer. Chapter One contrasts current girl's fiction with texts written about girlhood, followed with an analysis of the good-girl and bad-girl archetypes which are developed within the two groups of texts. I then consider the stylistic and structural elements presented within the fiction and the impact such elements may have on the girl public. In the conclusion, I consider the wider societal impacts of post-millennial girl fiction through social media, extended readership, cross-media influence and the responses of girl readers. Author Keywords: Feminist Criticism, girlhood, Gossip Girl series, public theory, Twilight series, young adult fiction

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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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