Graduate Theses & Dissertations

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Drink my beer, smoke my weed, my good friends are all I need
Past research has predominately supported an association between insecure attachment and substance use. More recent research has found that while individuals with secure attachment may use substances, they do so with less risk. The current study attempted to replicate the finding regarding secure attachment and substance use and examined the motivational drives behind why students use substances. A total of 318 undergraduate students completed self-report questionnaires examining peer attachment, alcohol and marijuana use, as well as motivations for use. Results indicated that students who reported low frequency use of alcohol or marijuana did not have significantly higher security ratings compared to students who reported increased use. Additionally, although hypothesized, secure attachment ratings were not associated with social facilitation or enhancement motivations. However, fearful and dismissing attachment ratings were both significantly associated with coping motives as predicted, while preoccupied and fearful attachment ratings were significantly associated with conformity motives. Lastly, results from multiple regressions suggest that coping and enhancement motivations are significant predictors of alcohol use, while enhancement motivations are marginally significant in predicting marijuana use. Author Keywords: alcohol, attachment, marijuana, motivation
Doing it Right
The cyanidation technique is currently a viable technique for gold recovery that can replace the present amalgamation technique in Guyana. To implement this technique effectively, laboratory scale experiments and at scale runs were conducted to determine the best particle size of the ore, cyanide concentration, and leaching time. In addition, the profitability of cyanidation was compared to the amalgamation technique so as to describe the economic value of cyanidation. Results indicated that up to 94% of gold can be recovered from the ore using an ore particle size of 150 (105 µm), meshes, a cyanide concentration of 0.05% and leaching for 24 h. An economic comparison of this technique with the amalgamation technique indicated that although initial costs are high for the cyanidation technique, profits as high as 83% can be achieved after initializing this method whereas profits would be capped at approximately 25% for the amalgamation technique. Keywords: gold recovery, cyanidation, mercury amalgamation, activated car Author Keywords: activated carbon, cyanidation, gold recovery, mercury amalgamation
Does boredom lead to ego-depletion? Examining the association between boredom and ego-depletion
Ego-depletion refers to the observation that using self-control at Time 1 (T1) in the sequential-task paradigm leads to worse self-control at Time 2 (T2; Baumeister et al., 1998). Self-control is often manipulated by varying the difficulty of the task used at T1. Recently, Wolff and colleagues (2020) suggested that failures to replicate the ego-depletion phenomenon may arise because simple tasks may be boring, therefore requiring self-control to maintain attention on the task. Three experiments (Experiment 1, N=60; Experiment 2, N=61; Experiment 3, N=59) are reported that examined whether boredom at T1 predicted self-control at T2. A simple Go/No-Go task was used at T1. The ratio of Go to No-Go trials was changed across experiments to explore how the properties of the boring task impacted the association between boredom and self-control. When responding was frequent, increased boredom at T1 was associated with fewer anagrams correctly solved (Experiment 1 and 3), and more self-reported fatigue at T2 (Experiment 1), consistent with boredom leading to ego-depletion. However, when responding was infrequent (Experiment 2), increased boredom at T1 was associated with more correctly solved anagrams at T2, suggesting that the properties of a boring task change the psychological outcome that task has on self-control. Author Keywords: attention, boredom, ego-depletion, executive function, self-control
Do birds of a feather flock together
Populations have long been delineated by physical barriers that appear to limit reproduction, yet increasingly genetic analysis reveal these delineations to be inaccurate. The eastern and mid-continent populations of sandhill cranes are expanding ranges which is leading to convergence and warrants investigation of the genetic structure between the two populations. Obtaining blood or tissue samples for population genetics analysis can be costly, logistically challenging, and may require permits as well as potential risk to the study species. Non-invasively collected genetic samples overcome these challenges, but present challenges in terms of obtaining high quality DNA for analysis. Therefore, methods that optimize the quality of non-invasive samples are necessary. In the following thesis, I examined factors affecting DNA quality and quantity obtained from shed feathers and examined population differentiation between eastern and mid-continent sandhill cranes. I found shed feathers are robust to environmental factors, but feather size should be prioritized to increase DNA quantity and quality. Further, I found little differentiation between eastern and mid-continent populations with evidence of high migration and isolation-by-distance. Thus, the two populations are not genetically discrete. I recommend future population models incorporate migration between populations to enhance our ability to successfully manage and reach conservation objectives. Author Keywords: feathers, genetic differentiation, non-invasive DNA, population genetics, population management, sandhill crane (Antigone canadensis)
Diversity, Biogeography, and Functional Traits of Native Bees from Ontario’s Far North and Akimiski Island, Nunavut
Bees (clade Anthophila), are poorly studied in northern Canada, as these regions can be difficult to access and have a short growing season. This study examined bees from two such regions: Ontario’s Far North, and Akimiski Island, Nunavut. I present this study as the largest biogeographical study of bees performed in these remote areas to enhance knowledge of northern native bees. I found 10 geographically unexpected species in Ontario and on Akimiski Island. Rarefaction and the Chao 1 Diversity Index showed that Akimiski is nearly as diverse as the Far North of Ontario, a significantly larger area. I also found, based on log femur length versus latitude, Bombus worker size was consistent with Bergmann’s rule, and there were no apparent statistical differences in the community weighted means of functional traits between the Far North’s Boreal Shield and Hudson Bay Lowlands ecozones. This work provides invaluable knowledge of the native bee species from these regions, which has implications for their future conservation. Author Keywords: Akimiski Island, Bergmann's rule, Chao 1, Community-weighted means, native bees, rarefaction
Distribution of Cluster Fly Species (Pollenia, spp. Diptera
This thesis looks at the genus Pollenia: historically where they were first introduced into Canada and spatially, where they are found now. This project involved me identifying 2211 files, sorted from the 3 years of field specimens obtained in 2011, 2012, 2013. P. pediculata was the most abundant and widespread, yielding 1272 specimens out of 2211, and it was found in all provinces sampled. The previous understanding of all Pollenia specimens as being P. rudis appears to be incorrect both in terms of actual number of species – which is known – and how prevalent it is. P. rudis comprised only 20% of the entire collection. The least common was P. griseotomentosa, occurring as 45 of 2211, or 2%. I found new eight first provincial records: four species in Alberta (P. angustigena, P. labialis, P. rudis, P. vagabunda) , one species for Saskatchewan (P. pediculata), two for New Brunswick (P. griseotomentosa, P. labialis), and one for Nova Scotia (P. labialis). P. labialis was new to three provinces, the other species to one province each. Author Keywords: Calliphoridae, Canada, Cluster Fly, Distribution, Pollenia, Provincial Records
Dissent Denied
In June 2010, the Group of Twenty (G20) met in Toronto, Ontario. The summit drew large-scale protests that culminated in mass arrests and extensive civil rights violations. Given these outcomes, this thesis examines the security spectacle of the summit to assess the evolving state of public order policing and social movement protest in Canadian law and politics. Connecting the securitization of the summit to the politics of neoliberalism, I argue these overlapping forces helped foment the criminalization of political dissent during the 2010 Toronto G20. Author Keywords: mega-events, neoliberalism, public order policing, securitization, security, social movements
Disease ecology of ophidiomycosis in free-ranging snakes
Ophidiomycosis (snake fungal disease) is caused by the pathogen Ophidiomyces ophiodiicola. Infected snakes exhibit dermal lesions, occasional systemic infections, and, in some cases, mortality. We studied snakes at Rondeau Provincial Park, Ontario, Canada, to explore whether ophidiomycosis develops during brumation or year-round. Throughout their active season, we quantified the prevalence of clinical signs of the disease on snakes and conducted qPCR of skin swabs to determine the prevalence of O. ophiodiicola on snakes. Prevalence of O. ophiodiicola and disease symptoms were highest on eastern foxsnakes (Pantherophis vulpinus) and very rare on other snake species. In P. vulpinus, pathogen and clinical sign prevalence was highest, directly after emergence from overwintering, with the majority of P. vulpinus being able to resolve clinical signs of ophidiomycosis by the return of winter. When we analyzed the survivorship of P. vulpinus we determined that the likelihood of a snake dying with ophidiomycosis is similar to a snake dying without ophidiomycosis. Given that P. vulpinus were the most affected species at our study site, ophidiomycosis does not appear to pose an imminent threat to our study population of P. vulpinus under current conditions. Author Keywords: Eastern Foxsnake, Fitness, Ophidiomycosis, Pantherophis vulpinus, Seasonal trends, Snake fungal disease
Discriminating grey wolf (Canis lupus) predation events in a multi-prey system in central Saskatchewan
I investigated if spatio-temporal behaviour of grey wolves (Canis lupus) determined via GPS collar locations could be used to discriminate predation events generally, and among prey species, in Prince Albert National Park during winter, 2013-2017. I used characteristics of spatio-temporal GPS clusters to develop a predictive mixed-effect logistic regression model of which spatial clusters of locations were wolf kill sites. The model suffered a 60 % omission error when tested with reserved data due to the prevalence of deer kills with correspondingly low handling time. Next, I found a multivariate difference in the percentage of habitat classes used by wolves in the 2 hours preceding predation events of different prey species, suggesting that wolf habitat use reflects prey selection at a fine-scale. My results highlight the difficulty and future potential for remoting discriminating wolf predation events via GPS collar locations in multi-prey ecosystems. Author Keywords: Canis lupus, GPS clusters, GPS collars, grey wolf, habitat use, predation
Discontinuities in stream networks
The network composition hypothesis (NCH) suggests that i) large confluence symmetry ratios (drainage area of the tributary relative to the mainstem) and ii) landscape differences (differences in landscape characteristics between the mainstem and tributary drainages) lead to greater ecological changes below confluences. As a test of the NCH, 34 confluences were sampled in southern Ontario to examine the effects of these two factors on benthic invertebrate communities to infer the degree of ecological change at confluences. Given the typology of streams surveyed, there was subtle evidence that benthic invertebrate communities below confluences changed as a function of confluence symmetry ratio and landscape differences. This indicates that abrupt changes in stream networks are not as common as theory may suggest. Further support for the network composition hypothesis may be found by examining a wider range of stream types and examining single-species responses. Author Keywords: benthic invertebrates, community similarity, landscape characteristics, stream networks, tributary
Disability-Mitigating Effects of Education on Post-Injury Employment Dynamics
Using data drawn from the Workplace Safety and Insurance Board’s (WSIB) Survey of Workers with Permanent Impairments, this thesis explores if and how the human capital associated with education mitigates the realized work-disabling effects of permanent physical injury. Using Cater’s (2000) model of post-injury adaptive behaviour and employment dynamics as the structural, theoretical, and interpretative framework, this thesis jointly studies, by injury type, the effects of education on both the post-injury probability of transitioning from non-employment into employment and the post-injury probability of remaining in employment once employed. The results generally show that, for a given injury type, other things being equal, higher levels of education are associated with higher probabilities of both obtaining and sustaining employment. Author Keywords: permanent impairment, permanent injury, post-injury employment
Dimensions of socio-cultural sustainability
Social and cultural sustainability is increasingly discussed in a variety of disciplines and in the growing body of sustainability literature. However there is a lack of clarity in how the concept is defined and poor understanding as to how it relates to other aspects of sustainability. To address this issue, this research explored current definitions and representations of socio-cultural sustainability in the literature and community perspectives on this topic through a case study in Hopedale, Nunatsiavut, Labrador. This research identifies gaps in current understandings of this concept, as well as differences between community and academic perspectives. Case study results emphasized the importance of strong social relationships, cultural identity, and connection to place as central elements of socio-cultural sustainability in a northern, Indigenous context. These findings are valuable for policy and decision makers, regarding approaches to community planning and supporting the social and cultural aspects of sustainability. Author Keywords: cultural sustainability, Hopedale, Inuit, Nunatsiavut, social sustainability, socio-cultural sustainability

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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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