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
Calcium Stress in Daphnia Pulicaria and Exposure to Predator-Derived Cues
In recent decades, declining calcium concentrations have been reported throughout lakes across the southern edge of the Canadian Shield. This raises concern as Daphnia populations have shown to be decreasing as they require calcium not only for survival but to mitigate predation risks. Therefore, the purpose of my thesis was to study the adaptability of Daphnia under calcium limitation and predation risk from Chaoborus. Firstly, I examined the effects of calcium limitation and Chaobours kairomones on daphniid life-history and population growth. I found that low calcium concentrations and Chaoborus kairomones affected Daphnia calcium content, life-history traits, and survival. Next, I focused on how calcium concentrations and Chaoborus abundance affected the calcium content and abundance of daphniids. During this study, I also examined the relationship between the abundance of Daphnia and a competitor Holopedium. I found that calcium concentrations and the abundance of Chaoborus affects daphniid abundance. Overall, results from this study show the importance of considering both predation risk and calcium declines to better determine daphniid losses. Author Keywords: anti-predator responses, Chaoborus, competition , Life-History traits, predator cues, Zooplankton
An Exploration of Partnership Models for Urban Conservation Land Management in Ontario
Partnerships for management of public parks have a long history, but little attention has been given to the current models of partnerships during a period of municipal austerity in Ontario. Using a qualitative assessment of transcripts from representatives of 10 municipal partner groups, this research considers what some of the current models are, the impact that they may have, and how municipalities may foster these partnership arrangements. The participating organizations demonstrated that their governance models evolved to suit their mandate, activities, and scope of interaction with their municipality. Additionally, this research corroborates past findings that efficacy of an organization is tied to their ability to partner with other agencies and act as a capacity amplifier. These results demonstrate how municipal conservation partnerships can be effectively applied to create enhanced financial outcomes and improved community engagement, while delivering community based environmental programming. Author Keywords: Conservation, Environmental Stewardship, Municipal Management, Partnership, Social Ecology, Urban Parks
Morphology, Production and Trade
The Africana IIA, an amphora subtype of the Africana II class, was produced in Africa Proconsularis (the present-day Tunisian Sahel) during the mid-Roman Imperial period (from the late 2nd c. A.D. to the middle decades of the 3rd c. A.D.), and was distributed around the western Mediterranean. Scholars have noted meaningful morphological variations on this subtype’s rim but had overlooked the information that these rims may convey. The preliminary analysis of the variations found on Africana IIA amphora rims yielded possible connections to various production sites or regions, distribution samples, and/or consumption sites, and suggested that at least some of the rim variants were indicative of origin. The rim variants also seemed to correlate to different trade routes, and potentially, different trade mechanisms, including private versus State interests. Author Keywords: Africa Proconsularis, Africana IIA amphora, ancient economy, Byzacena, ceramics, fabric analysis
Characteristics of Models for Representation of Mathematical Structure in Typesetting Applications and the Cognition of Digitally Transcribing Mathematics
The digital typesetting of mathematics can present many challenges to users, especially those of novice to intermediate experience levels. Through a series of experiments, we show that two models used to represent mathematical structure in these typesetting applications, the 1-dimensional structure based model and the 2-dimensional freeform model, cause interference with users' working memory during the process of transcribing mathematical content. This is a notable finding as a connection between working memory and mathematical performance has been established in the literature. Furthermore, we find that elements of these models allow them to handle various types of mathematical notation with different degrees of success. Notably, the 2-dimensional freeform model allows users to insert and manipulate exponents with increased efficiency and reduced cognitive load and working memory interference while the 1-dimensional structure based model allows for handling of the fraction structure with greater efficiency and decreased cognitive load. Author Keywords: mathematical cognition, mathematical software, user experience, working memory
Nassau Mills Complex
The objective of this thesis is to develop and implement a heritage plan for the Nassau Mills Complex, a locally-significant Euro-Canadian historical site that operated on what is now Trent University’s campus in Peterborough, Ontario. Within the framework of public archaeology and Cultural Heritage Management (CHM), emphasis is placed on the importance of protecting the site and its historic remains in order for present and future generations to appreciate and enjoy. Data was gathered by way of field and archival research, as well as through consultations with various archaeological and museological professionals. Of particular concern is evaluating how the Complex is significant to Peterborough, how it should be commemorated, public engagement and the importance of information accessibility, and the potential issues that may arise as a result of this project. In addition, recommendations regarding how the site and its collections should be preserved and presented to the collective society are also examined. Author Keywords: Cultural Heritage Management, Nassau Mills Complex, Peterborough, Preservation, Public Archaeology, Trent University
Changes in the Representations of Women from the 1980s Turkish Cinema to New Turkish Cinema
The thesis examines the changes in the representations of women in Turkish cinema from the 1980s through the 2000s in terms of semiotic codes. To demonstrate the shifts of the representations of women over three decades, four films directed by two representative filmmakers of the 1980s and the 2000s are analyzed within the context of gender codes: A Sip of Love (Atıf Yılmaz/1984), The Night, Angel and Our Gang (Atıf Yılmaz/1994), The Third Page (Zeki Demirkubuz/1999) and Envy (Zeki Demirkubuz/2009). Using gender as code in deconstructing women’s characteristics and their representations in the films, the research highlights the structural image of women in the semiotic sense. The stereotypical representations in Turkish cinema question social norms, patriarchy, and Islamic norms in Turkey. Author Keywords: Gender codes, Islam, Patriarchy, Semiotics, The representations of women , Turkish cinema
influence of tree species litterfall on soil chemistry and implications for modelling soil recovery from acidification
Decades of acidic deposition have depleted base cation pools in soil over large parts of eastern north America, including the Muskoka-Haliburton region of central Ontario. This region has also experienced a shift in forest species composition over the past 200 years, favouring sugar maple (Acer saccharum Marsh.) at the expense of species such as white pine (Pinus strobus L.) and eastern hemlock (Tsuga canadensis (L.) Carr.). This shift in species composition may have changed soil chemistry over time due to differences in nutrient and metal inputs in litterfall. An analysis of litterfall and soil chemistry was conducted for five tree species commonly found across central Ontario. Stands were established in the Haliburton Forest & Wild Life Reserve and were dominated by one of balsam fir (Abies balsamea (L.) Mill.), eastern hemlock, white pine, sugar maple, or yellow birch (Betula alleghaniensis Britt.). Analysis of mineral soil oxides suggested that these stands were established on similar parent material. Deciduous dominated stands (maple and birch) had greater litterfall mass compared with conifer stands (fir, hemlock, and pine), generally leading to greater macronutrient inputs to the soil. Elemental cycling through the organic horizons was more rapid in deciduous stands, with base cations having the shortest residence times. This suggests that a change from greater conifer dominance to mixed hardwood forests may lead to more rapid elemental cycling and alter the distribution of elements in soil. Forests in the region are typically mixed and the resulting differences in soil chemistry may influence model predictions of soil recovery from acidification. Laboratory leaching tests indicated that both stand type and the acidity of simulated rainwater inputs influenced soil solution chemistry, with deciduous stands generally having a greater buffering capacity than sites dominated by coniferous species. Changes in soil chemistry were examined for each stand type using the Very Simple Dynamic (VSD) biogeochemical model. Simulations showed that soil base saturation began to increase following lows reached around the year 2000, and similar patterns were observed for all stands. When sulphur (S) and nitrogen (N) deposition were held constant at present rates, soil base saturation recovery (toward pre-1900 levels) was marginal by 2100. With additional deposition reductions, further increases in base saturation were minor at all sites. In conjunction with additional deposition reductions, the elimination of future forest harvesting allowed for the greatest potential for recovery in all stands. Overall, these results suggest that changes in forest cover may influence soil chemistry over time, most notably in the organic soil horizons. However, forecasted recovery from acidification is expected to follow similar patterns among stands, since differences in soil chemistry were less significant in the mineral soil horizons which compose a greater proportion of the soil profile. Author Keywords: base cation decline, forest harvesting, litterfall, mineral weathering, soil acidification, VSD model
Short photoperiod lowers visceral adiposity and shifts the molecular clock in Peromyscus leucopus
The length of photoperiod can alter circadian rhythms and change fat depot mass whencombined with environmental temperatures below thermoneutral. To isolate photoperiod effects, we compared the effects of long and short photoperiod exposure at thermoneutrality in photoperiod sensitive, F1 generation adult male white-footed mice (P. leucopus). Mice were housed in long-day or short-day photoperiod conditions at thermoneutrality for 4 weeks. Short photoperiod decreased vWAT mass without changing body weight, scWAT or iBAT mass, or calorie consumption. Short photoperiod increased Adrβ3 and Lpl mRNA expression in vWAT with no change in Ucp1, Pgc1a or Hsl. vWAT Per1, Per2 and Nr1d1 mRNA expression were aligned to the onset of dark and food intake, while Bmal1 and Clock were misaligned. These findings suggest that short photoperiod per se can decrease visceral fat accumulation, without activating thermogenesis, reinforcing that environmental photoperiod should be considered when researching cause and prevention of obesity. Author Keywords: adiposity, circadian rhythm, clock genes, obesity, Peromyscus, photoperiod
Differential expression of cytochrome b5s in Giardia intestinalis during nitrosative stress and encystation
The waterborne protozoan Giardia intestinalis cycles between the environmentally-resistant and infectious cyst and the metabolically-active trophozoite that adheres to the epithelial lining of the small intestine. Adhesion can trigger the innate immune response in epithelial cells, including the synthesis of the free radical nitric oxide (NO) that inhibits cell proliferation and encystation of trophozoites. In this work changes in protein expression of three Giardia isotypes of the redox heme protein cytochrome b5 (gCYTb5 I, II and III) were studied in response to either nitrosative stress or induction of encystation. Two nitrosative stressors, sodium nitrite and the NO donor DETA-NONOate, were used at sub-lethal concentrations (0.5 mM and 0.05 mM, respectively) that do not affect cell proliferation until later time points so that subtle changes in protein expression could be observed in the absence of other confounding factors. Nucleolar gCYTb5-I and nucleoplasmic gCYTb5-III expression patterns were similar in trophozoites exposed to either stressor, showing gradual increases in expression with peaks between 4 and 12 hours, which indicates these cytochromes respond to nitrosative stress and possibly to potential DNA damage in Giardia. In contrast, gCYTb5-II of the peripheral vacuoles, which are part of the endocytic pathway of Giardia, showed little change in expression in response to either stressor. However, changes in gCYTb5-II expression were observed in encysting trophozoites, with a 1.4-fold increase in protein levels at seven hours after induction of encystation, followed by a gradual decrease in expression. These changes are consistent with previous mRNA analysis done in our laboratory and suggest a role for gCYTb5-II in the increase in nutrient uptake during early encystation. Author Keywords: cytochrome, encystation, Giardia, heme, nitrosative, parasite
Creation During Abandonment
This thesis addresses the excavation and analysis of the Hingston Group, a small courtyard group just south of the ceremonial core of the Ancient Maya city of Ka’kabish in North-Central Belize. I use settlement and household archaeological theory to understand the functions, occupation history, and status of this residential group. I also rely on entanglement theory, along with the hypothesizes presented by Palka (2003) and McAnany (1995), to create a possible interpretation for the reasons why we see what we do in the Hingston Group during its main period of occupation. The Hingston Group is composed of three structures and two chultuns (underground storage areas). Research teams excavated both chultuns during prior field seasons and found burials from the Postclassic and Late Formative Periods. This information led to the assumption that the occupation of these structures would correspond to one, or both, of these periods. However, we found that this courtyard group was occupied during a period when the rest of the core of Ka’kabish was abandoned. Along with this, excavators found an ephemeral occupation into the Colonial Period; these two new periods of occupation have expanded our understanding of the chronological history of Ka’kabish. Author Keywords: formative to postclassic, household archaeology, Maya, settlement archaeology
Prioritizing Restoration Potential within Protected Areas in Haliburton County, Ontario
Ecological restoration helps managers of protected areas respond to challenges presented by factors that threaten ecological integrity and respond to residual effects of previous land use. Many protected areas require restoration on sections of the property, due to previous land use. The objective of this thesis is to present criteria that assist ecological restoration professionals in assessing the potential of restoration projects within a protected area, based on the restoration wheels from the International Principles and Standards for the Practice of Ecological Restoration. The criteria were discovered from a review of the literature and reinforced from interviews with experienced restoration practitioners and a focus group session with key members of the Haliburton Highlands Land Trust (HHLT). Based on the combination of biophysical and socioeconomic values in the restoration wheels, they are presented in the form of a five-star assessment system to create long-term restoration goals for properties of the HHLT and protected areas in general. These long-term restoration goals can be utilized in conjunction with the wheels and five-star assessment tools to prioritize restoration projects Author Keywords: Determining Project Potential, Ecological Restoration, Evaluating Success, Haliburton, Land trusts, Restoration Wheels

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Format: 2024/03/04