Graduate Theses & Dissertations

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An Analysis of Hafted Biface Variability in the Kawartha Lakes and Trent River Drainage Region
The objective of this thesis is to evaluate the temporal sensitivity of morphological variability in hafted bifaces in the Kawartha Lakes and Trent River drainage region. This provides a base of information that will enable future analyses that address the possible sources of this variability and to test the robustness of existing typological categories of hafted bifaces for relative dating. This base of information is established via the use of a principal component analysis of shape, raw material, and use-life data from a large sample of hafted bifaces in the region, using a new geometric morphometrics method designed to improve the accuracy of shape representation. The results of the analysis indicate that while certain typological categories may represent distinct morphotypes that are temporally sensitive, the majority of typological categories in the sample show high, overlapping morphological variability that cannot be confidently correlated temporally based on shape alone. Author Keywords: Geometric Morphometrics, Morphological Variability, Ontario Archaeology, Principal Component Analysis, Project Point Morphology, Projectile Point Typology
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
Using environmental DNA (eDNA) metabarcoding to assess aquatic plant communities
Environmental DNA (eDNA) metabarcoding targets sequences with interspecific variation that can be amplified using universal primers allowing simultaneous detection of multiple species from environmental samples. I developed novel primers for three barcodes commonly used to identify plant species, and compared amplification success for aquatic plant DNA against pre-existing primers. Control eDNA samples of 45 plant species showed that species-level identification was highest for novel matK and preexisting ITS2 primers (42% each); remaining primers each identified between 24% and 33% of species. Novel matK, rbcL, and pre-existing ITS2 primers combined identified 88% of aquatic species. The novel matK primers identified the largest number of species from eDNA collected from the Black River, Ontario; 21 aquatic plant species were identified using all primers. This study showed that eDNA metabarcoding allows for simultaneous detection of aquatic plants including invasive species and species-at-risk, thereby providing a biodiversity assessment tool with a variety of applications. Author Keywords: aquatic plants, biodiversity, bioinformatics, environmental DNA (eDNA), high-throughput sequencing, metabarcoding
Frequency-time and polarization considerations in spectral-focusing-based CARS microscopy
Spectral-focusing-based coherent anti-Stokes Raman scattering (SF-CARS) microscopy is a powerful imaging technique that involves temporally and spectrally stretching ultrashort laser pulses and controlling their frequency-time characteristics. However, a broader and more detailed understanding of the frequency-time characteristics of the laser pulses and signals involved, how they are related, and how they influence important aspects such as the spectral resolution is needed to understand the full potential of SF-CARS systems. In this work, I elucidate these relationships and discuss how they can be exploited to optimize SF-CARS microscopy setups. I present a theoretical analysis of the relationships between the spectral resolution, the degree of chirp-matching, and pulse bandwidth in SF-CARS. I find that, despite allowing better ultimate spectral resolution when chirp-matching is attained, the use of the broadest bandwidth pulses can significantly worsen the spectral resolution if the pulses are not chirp-matched. I demonstrate that the bandwidth of the detected anti-Stokes signal is minimized when the pump is twice as chirped as the Stokes, meaning that (perhaps counter-intuitively) a narrow anti-Stokes bandwidth does not imply good spectral resolution. I present approximate expressions that relate the bandwidths of the pump, Stokes, and anti-Stokes pulses to the degree of chirp-matching and outline how these could be used to estimate the amount of glass needed to attain chirp-matching. I develop a spectral-focusing-based polarization-resolved (SFP-CARS) setup, by modifying our existing system, to explore the merits of integrating polarization-dependent detection as an add-on to existing SF-CARS setups. By using the system to study polarization-dependent features in the CARS spectrum of benzonitrile, I assess its capabilities and demonstrate its ability to accurately determine Raman depolarization ratios. Ultimately, the detected anti-Stokes signals are more elliptically polarized than desired, hindering a complete suppression of the non-resonant background. Nevertheless, I find that the SFP-CARS setup is a useful tool for studying polarization-dependent features in the CARS spectra of various samples and is worthy of further investigation. This work clarifies several technical aspects of SF-CARS microscopy and provides researchers with valuable information to consider when working with SF-CARS microscopy systems. Author Keywords: coherent anti-Stokes Raman scattering, nonlinear microscopy, polarization, spectral focusing, spectroscopy
Older Voluntarism and Rural Community Sustainability
With regards to building knowledge about rural aging, there is a gap in understanding of the diversity of older rural people’s experiences and the interaction between older rural people and the development trajectories of aging rural communities. One way to examine these experiences and interactions is through voluntarism; the activities of volunteers and voluntary organizations, which are pivotal for supporting aging in place in often-underserviced rural communities. To address this gap, this thesis features a community-based case study with a volunteer-based rural library in Ontario, Canada and was aimed at understanding the experiences of older library volunteers, examining the challenges of a rural library volunteer program and exploring how they contribute to rural community sustainability. Through surveys (n=87), interviews (n=48) and focus groups (n=6) with library volunteers, staff, board members and community leaders the findings demonstrate how older voluntarism is felt through the lived experiences of individual volunteers, poses interpersonal, operational and structural challenges, and can potentially contribute to the sustainability of rural communities. The thesis contributes to our understanding of the rural, older voluntarism and provides recommendations for ways to sustain library volunteer programs. Author Keywords:
Examining the Role of Intermediary Organizations in Participatory Planning
This research evaluates the role of GreenUP, a non-profit in Peterborough, Ontario, as the intermediary organization for NeighbourPLAN. The project examines GreenUP’s role in facilitating and managing NeighbourPLAN, a participatory planning project with multiple local partners and actors. Six critical success factors are used to understand and conceptualize intermediary success (adapted from Holden et al., 2016). Critical success factors include knowledge; governance; relationships; resources; activities; and motivation. Findings from the research highlight the importance of trust, resources, and time within this framework. Author Keywords: Community Based Research, Intermediary, Neighbourhood, Non-profit, Participatory Planning, Partnership Structure
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
Practicing and Rewarding Task-Relevant Motor Variability to Optimize Motor Performance
It is universally accepted that human motor performance is variable in both its timing and spatial qualities. However, it is unclear to what extent motor variability impedes performance when learning a new skill and to what extent it enables our ability to learn. The first experiment examined whether performance during a test task depended on whether participants practiced to constrain or vary the task-relevant parameter. Participants used their right hand to make simple point-to-point movements. Results demonstrated the importance of paying attention to test task demands to evaluate which form of practice is most beneficial. The second experiment examined whether levels of variability could be manipulated using a reward-based paradigm to enhance learning when adapting to a perturbation of a simple visually-guided reaching movement. A reward-based feedback task was designed to encourage exploration along the task-relevant dimension, specifically movement direction variability. Overall, I did not find any significant results. Author Keywords: Adaptation, Motor Control, Motor Learning, Reaching
effects of particulate matter on the fate and toxicity of silver nanoparticles
As an emerging contaminant, the antimicrobial agent silver nanoparticles (AgNPs) have been receiving considerable attention to determine their potential effects to aquatic ecosystems. However, estimates of aquatic consumer survivorship and other toxicological endpoints vary considerably among experiments, largely due to the environment in which the test takes place. Throughout this thesis I aim to understand which natural environmental variables impact toxicity to the common aquatic consumer Daphnia. I focus on the effects of particulate matter as it may play a role in animal nutrition as well as interact with AgNPs. I explore particulate matter’s effect on survival in the complex matrices including other natural variables that could impact toxicity. I conduct a series of complimentary field and laboratory studies to understand how particles impact AgNP toxicity and how those interactions vary within whole lake ecosystems. Using laboratory studies, I establish that algal particles mitigate the toxic effects of AgNPs on Daphnia survival through removing Ag from the water column and that phosphorus increases this effect. Using wild Daphnia and lake water, I demonstrate the ability of particulate matter to mitigate toxicity in complex natural settings. It was also one of the major predictors of AgNP toxicity to Daphnia along with dissolved organic carbon and daphnid seasonal health. Finally, using a whole lake AgNP addition experiment, I demonstrate that particles and AgNPs interact variably in the lake. Silver from AgNPs binds to particles and is removed to the sediments through the actions of settling particles without impacting the dynamics of living communities. Overall, I am able to demonstrate that the natural components of lake ecosystems, especially particulate matter, are able to mitigate the effects of AgNPs in lake ecosystems to a point where they likely will be never pose a threat to the survivorship of aquatic consumers such as Daphnia. Author Keywords: Daphnia, ecotoxicity, particulate matter, Silver nanoparticles, whole lake experiment
Temperature effects on the routine metabolic rates of brook trout (Salvelinus fontinalis) eggs, alevin and fry
Early developmental stages of cold-adapted ectotherms such as brook trout (Salvelinus fontinalis) are at risk of mortality with increasing water temperatures because of their sensitivity to changes in their environment. I studied the mass and routine metabolic rate (RMR) of wild-origin brook trout eggs, alevin and young fry reared at normal (5°C) and elevated (9°C) temperatures for the duration of the study or at mismatched temperatures. This setup determined if preconditioning acclimation for one temperature benefits or hinders the organism later in life. Three levels of biological organization (ancestry, population, family) were studied using Akaike’s Information Criterion (AIC) to identify models that best accounted for variation in the data. Family, mass and temperature were most important in predicting body mass and mass-adjusted RMR, although population and ancestral-level differences were also detected at some life stages. Strong variation in body mass and mass-adjusted RMR among families may indicate adaptive potential within brook trout populations to respond to increases in water temperature with climate change. Author Keywords: Acclimation, AIC, Brook trout (Salvelinus fontinalis), Environmental matching, Routine metabolic rate, Temperature
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

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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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1973 - 2033
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Format: 2023/03/27

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