Graduate Theses & Dissertations

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Sexting and Satisfaction
Sexting was explored in relation to cohabitation status, general and sexual communication, as well as the anxious and avoidant dimensions of attachment. The present study was focused the distinction between lifetime and recent sexting, in an attempt to more accurately assess the relationships between the examined factors and sexting behaviours. Individuals in long-distance relationships were more likely to report recently sexting and engaged more frequently than those in cohabitating relationships, but did not differ in their levels of sexual satisfaction. Recent sexters reported higher levels of sexual communication compared to lifetime sexters, and sexual communication was positively, though weakly, correlated with sexting frequency. The present study was unable to support a predictive relationship between recent sexting and levels of attachment anxiety or avoidance. These results highlight the importance of exploring the context in which sexting occurs, as well as distinguishing between lifetime and recent sexters in future sexting research. Author Keywords: Attachment, Long Distance Relationship, Recent Sexting, Satisfaction, Sexting, Sexual Communication
Nunavik Inuit Knowledge of Beluga
Socio-ecological systems are inherently complex and marine mammals are fundamentally challenging to study. In the Arctic, marine mammals occupy a central ecological role, as nutrient cyclers and as a source of food and culture for Indigenous peoples. Inuit have developed a rich knowledge system, which has not been fully actualized in application in most Arctic research. Considering the need for the best available information in marine mammal ecology, the research question guiding this dissertation was: How can multiple methods and approaches be used to more effectively gather, understand, and represent Inuit Knowledge for an improved understanding of marine mammal ecology? The dissertation investigates this question using a case study of beluga in Nunavik (Arctic Quebec) drawing on the expertise of hunters and Elders to better understand complex questions in marine mammal ecology. The thesis uses a transdisciplinary approach to address the dissertation objective and is comprised of a general introduction, followed by four chapters formatted as journal manuscripts, and closes with an integrated discussion and conclusion. The first manuscript examines the contributions of Traditional Ecological Knowledge (TEK) of beluga to marine mammal literature. The second manuscript uses a sub-set of data gathered through participant mapping to apply a mapping method to explore how the spatial aspects of TEK could be better documented, analyzed, and represented. The third and fourth papers are based on the knowledge shared by hunters and Elders. The third explores the questions ‘why do beluga migrate?’ and ‘what factors influence beluga movement?’. The fourth investigates aspects of beluga foraging ecology. This dissertation makes methodological contributions through the application of kernel density estimators to participant maps as a method for transforming multiple mapped narratives into a quantitative database. The understandings shared by hunters and Elders make significant ecological contributions, particularly to foraging (e.g. diet composition and seasonal energy intake), and movement ecology (e.g. potential drivers of migration). Broadly these findings contribute to our collective understanding of beluga ecology and have implications for wildlife management. Author Keywords: Arctic, Beluga biology, foraging ecology, Inuit Knowledge, migration, transdisciplinary
Making eDNA count
Environmental DNA (eDNA) is rapidly becoming an established method for the detection of species in aquatic systems and has been suggested as a promising tool to estimate species abundance. However, the strength of the relationship between eDNA concentrations and taxon abundance (density/biomass) can vary widely between species. I investigated the relationship between eDNA concentration and species abundance using two common and closely-related amphibians in eastern North America, the wood frog (Rana sylvatica) and northern leopard frog (Rana pipiens). I manipulated tadpole density in 80 L mesocosms and documented the relationship between tadpole density, biomass, and eDNA concentration. Species were comparable in biomass but differed in the amount of detectible genetic material produced; density and biomass were the superior abundance metric correlated with eDNA concentration for wood frogs and leopard frogs, respectively. However, increases in eDNA concentration reflected increasing tadpole biomass, therefore biomass is likely a better metric of abundance than density. Overall my findings support that eDNA concentration can be used as an index of species abundance, but that species-specific calibration may be needed before eDNA concentration can be effectively translated to an abundance metric. Future research should refine our understanding of how biotic and abiotic factors influence eDNA production, degradation, and recovery across species, before the method can receive widespread use as a monitoring tool in natural settings. Author Keywords: abundance estimates, environmental DNA, mesocosm, Rana pipiens, Rana sylvatica
Retrograde Amnesia of Fear Memories Following Pentylenetetrazol Kindling
Memories pertaining to fearful events are some of the most salient and long-lasting memories, as they are critical to the survival of an organism. Seizures induce aberrant changes within temporal lobe and limbic brain structures that are critical for supporting fear memories. Seizures can occur at any time; therefore, it is imperative that research address how seizures impact previously learned information. The present series of experiments demonstrate that pentylenetetrazol-kindling induces retention deficits of previously acquired context fear memories in male rats. Kindling induced subsequent fear learning deficits but did not impact spatial learning. Additionally, following kindling, volumetric increase was observed within the hippocampal subfield CA3, as well as increased neural activation within the hippocampal subfield CA1. The results of this work suggests that chronic seizures can alter the function of neural networks important for supporting and retrieving previously acquired memories. Author Keywords: amygdala, anterograde amnesia, context fear conditioning, hippocampus, retrograde amnesia, seizures
Utilizing Class-Specific Thresholds Discovered by Outlier Detection
We investigated if the performance of selected supervised machine-learning techniques could be improved by combining univariate outlier-detection techniques and machine-learning methods. We developed a framework to discover class-specific thresholds in class probability estimates using univariate outlier detection and proposed two novel techniques to utilize these class-specific thresholds. These proposed techniques were applied to various data sets and the results were evaluated. Our experimental results suggest that some of our techniques may improve recall in the base learner. Additional results suggest that one technique may produce higher accuracy and precision than AdaBoost.M1, while another may produce higher recall. Finally, our results suggest that we can achieve higher accuracy, precision, or recall when AdaBoost.M1 fails to produce higher metric values than the base learner. Author Keywords: AdaBoost, Boosting, Classification, Class-Specific Thresholds, Machine Learning, Outliers
Balance is key
While preferences for symmetry are seemingly universal, they can be seen at their most extreme among individuals high in trait incompleteness. As yet, it is unclear why incompleteness yields heightened symmetry preferences. Summerfeldt et al. (2015) speculated that individuals high in incompleteness may develop heightened preferences for symmetry due to its greater perceptual fluency. Accordingly, the aim of the present set of three experiments was to examine this relationship. Implicit preferences for symmetry were measured using a modified version of the Implicit Association Test (IAT) reported by Makin et al. (2012). Experiments 1 (N = 24) and 2 (N = 24) examined whether the general implicit preferences for symmetry and influence of perceptual fluency reported by Makin et al. (2012) extended to a within-subjects design. Experiment 3 (N = 86) examined whether trait incompleteness is related to greater implicit preferences for symmetric stimuli, and whether perceptual fluency affects this association. Results showed that incompleteness and implicit preferences were related, and that incompleteness-related differences in preferences were eliminated when the patterns were equally perceptually fluent, supporting the idea that incompleteness-related preferences for symmetry are linked to perceptual fluency. Implications of these findings are discussed. Author Keywords:
Situating Copper Bells in Prehispanic Southwest Societies
This thesis examines the spatial, temporal, and contextual distribution of copper bells in the Greater Southwest region and how they are situated in archaeological literature. To date, 672 copper bells have been found in at least 113 different Southwestern sites dating from ca. A.D. 900-1450, though there is no archaeological evidence for metallurgical activities in the area at this time. The origin of copper bells has been assumed to be West Mexico, a region known for its metallurgical traditions and whose inhabitants produced copious amounts of similar bells. Various lists of copper bells discovered have been compiled over the years, but little consideration has been given to the role these artifacts may have played in Southwestern societies. Copper bells are frequently labelled as prestige goods in archaeological literature, a term which fails to account for their significant depositional variation. By updating the database of known Southwestern copper bells, it becomes possible to examine these contextual distributions in greater detail. It is concluded that the prestige goods model is not suitable for Southwestern copper bells in many cases, and that alternative frameworks such as inalienable possessions are a better fit for these artifacts. Author Keywords: Archaeology, copper bells, inalienable possesions, interaction, U.S. Southwest
Thinking High When Feeling Shy
Social anxiety often co-occurs with substance use disorders – various psychological variables, contextual factors, and implicit cognitions may help explain their relationship. This thesis examined whether social anxiety and psychological variables (jointly and independently) helped predict substance use and related problems. It also explored whether social anxiety group membership helped predict implicit cannabis-sedation associations and substance use desirability. A sample of undergraduate student volunteers (N = 65) completed a computer task, questionnaires with anxiety-provoking vignettes, and online questionnaires. Results indicate that fear of negative evaluation and anxiety sensitivity are important predictors of alcohol and cannabis (respectively) use and problems. Social anxiety group was related to increased cannabis desirability in performance contexts. No significant implicit cannabis-sedation associations were identified. Our findings highlight the importance of certain variables in social anxiety and substance use relationships, and considering contextual factors when assessing substance desirability. It also provides preliminary evidence of a novel implicit cannabis-sedation measure. Author Keywords: Coping, Emotion, Implicit Cognition, Social Anxiety, Substance Use
Enhancing post-mortem interval estimates
The growth of immature insects that develop on human remains can be used to estimate a post-mortem interval (PMI). PMI estimate confidence is negatively affected by: larval killing and preservation methods altering their size, limited morphological parameters to assess larval growth and therefore age, and few available alternate species development data. I compared live specimens to preserved specimens of the same development stages to assess the effects of killing-preservation techniques on morphology, and I introduce a new method that uses digital photography to examine maggot mouthparts for stage grading of Phormia regina. Digital photographic methods enable live insects to be quantified and improve approximations of physiological age. I then use these digital methods to produce a growth-rate model for a beetle commonly found on human remains, Necrodes surinamensis, providing data for PMI estimates that was previously unavailable. Author Keywords: Forensic Entomology, Insect development, Morphometrics, Necrodes surinamensis, Phormia regina, Postmortem interval
cascading effects of risk in the wild
Predation risk can elicit a range of responses in prey, but to date little is known about breadth of potential responses that may arise under realistic field conditions and how such responses are linked, leaving a fragmented picture of risk-related consequences on individuals. We increased predation risk in free-ranging snowshoe hares (Lepus americanus) during two consecutive summers by simulating natural chases using a model predator (i.e., domestic dog), and monitored hare stress physiology, energy expenditure, behaviour, condition, and habitat use. We show that higher levels of risk elicited marked changes in physiological stress metrics including sustained high levels of free plasma cortisol which had cascading effects on glucose, and immunology, but not condition. Risk-augmented hares also had lowered daily energy expenditure, spent more time foraging, and decreased rest, vigilance, and travel. It is possible that these alterations allowed risk-exposed hares to increase their condition at the same rate as controls. Additionally, risk-augmented hares selected, had high fidelity to, and were more mobile in structurally dense habitat (i.e., shrubs) which provided them additional cover from predators. They also used more open habitat (i.e., conifer) differently based on locale within the home range, using familiar conifer areas within cores for rest while moving through unfamiliar conifer areas in the periphery. Overall, these findings show that prey can have a multi-faceted, highly plastic response in the face of risk and can mitigate the effects of their stress physiology given the right environmental conditions. Author Keywords: behaviour, condition, daily energy expenditure, predator-prey interactions, snowshoe hare, stress physiology
Asserting sexual (dis)interest
Sexual assertiveness encompasses skills in refusing unwanted sexual situations and bringing about wanted sexual situations. Measures of sexual assertiveness typically assess both refusal and initiation aspects, yet there is a dearth of research examining these skills in relation to one another. The present study examined the relationship between these skillsets in women, exploring predictors of each. Initiation and refusal assertiveness were moderately correlated. Additionally, the relationship between them was not entirely explained by general assertiveness, indicating that there is something unique to assertiveness in the sexual context. Committed relationship context and erotophilic disposition specifically predicted initiation assertiveness. Less endorsement of the sexual double standard and fewer approach motivations for engaging in unwanted sex specifically predicted refusal assertiveness. Few differences emerged in predictors of assertiveness types when comparing sexual orientation groups, yet non-heterosexual women reported slightly lower levels of refusal assertiveness. Implications for sexual education, therapy, and future research are discussed. Author Keywords: sexual assertiveness, sexual autonomy, sexual compliance, sexual double standard, sexual satisfaction, sexual self-disclosure
mechanistic analysis of density dependence in algal population dynamics
Population density regulation is a fundamental principle in ecology, however there remain several unknowns regarding the functional expression of density dependence. One prominent view is that the patterns by which density dependence is expressed are largely fixed across a species, irrespective of environmental conditions. Our study investigated the expression of density dependence in Chlamydomonas reinhartti grown under a gradient of nutrient densities, and hypothesized that the relationship between per capita growth rate (pgr) and population density would vary from concave-up to concave-down as nutrients became less limiting. Contrary to prediction, we found that the relationship between a population's pgr and density became increasingly concave-up as nutrient levels increased. Our results suggest that density dependence is strongly variable depending on exogenous and endogenous processes acting on the population, implying that expression of density regulation depends extensively on local conditions. Population growth suppression may be attributable to environments with high intraspecific competition. Additional work should reveal the mechanisms influencing how the expression of density dependence varies across populations through space and time. Author Keywords: Chlamydomonas reinhartti, density dependence, logistic model, population dynamics, single species growth, theta-logistic equation

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Format: 2023/01/31