Graduate Theses & Dissertations

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Context Fear Memory
Distributing contextual fear episodes makes the memory become HPC-independent, meaning increasingly reliant on non-HPC memory structures. It is unclear, however, whether distribution of the conditioning episodes alone is sufficient or whether a combination of distribution and high conditioning saliency is necessary to make the memory become HPC-independent. To resolve this issue, rats were trained using a distributed contextual fear conditioning protocol in which foot-shocks were manipulated to create a low (0.4mA), intermediate (0.7 mA) and high (1.0 mA) saliency condition. This thesis also aimed to determine brain structures supporting the HPC-independent memory by assessing retention-induced c-fos expression in the basolateral- amygdala, perirhinal and anterior cingulate cortices. The results suggest that HPC lesion rats in the high saliency condition displayed similar level of freezing as control rats, indicating “strongly salient” and distributed episodes creates a HPC independent memory. c-fos expression suggests together, an increased context representation in the perirhinal and anterior cingulate cortices and a strengthened fear representation in the basolateral-amygdala supports the HPC-independent memory. Author Keywords: context fear memory, distributed reinstatements, hippocampus, IEG, rat, saliency
Altered Hippocampal Regulation of Immediate Early Genes after Pentylenetetrazol-Induced Seizures
Seizures induce long-term changes in gene expression in the hippocampus. Experimental evidence has demonstrated a significant effect of epileptic activity on the activity of neurons that participate in complex cognitive and behavioural processes. The present series of experiments involving kindling with subconvulsive doses of PTZ demonstrates a link between seizures and altered immediate early gene expression within the hippocampus and dentate gyrus. In addition, newborn hippocampal neurons were shown to have decreased induction of plasticity-related genes, suggesting deficits in activity-dependent recruitment. These findings may shed light on the mechanisms underlying epileptogenesis and epilepsy-related hippocampal dysfunction in human patients. Author Keywords: hippocampus, IEGs, kindling, neurogenesis, seizures
Assessing Molecular and Ecological Differentiation in Wild Carnivores
Wild populations are notoriously difficult to study due to confounding stochastic variables. This thesis tackles two components of investigating wild populations. The first examines the use of niche modeling to quantify macro-scale predator-prey relationships in canid populations across eastern North America, while the second examines range-wide molecular structure in Canada lynx. The goal of the first chapter is to quantify niche characteristics in a Canis hybrid zone of C. lupus, C. lycaon, and C. latrans to better understand the ecological differentiation of these species, and to assess the impacts of incorporating biotic interactions into species distribution models. The goal of the second chapter is to determine if DNA methylation, an epigenetic marker that modifies the structure of DNA, can be used to differentiate populations, and might be a signature of local adaptation. Our results indicated that canids across the hybrid zone in eastern North America exhibit low levels of genetic and ecological differentiation, and that the importance of biotic interactions are largely lost at large spatial scales. We also identified cryptic structure in methylation patterns in Canada lynx populations, which suggest signatures of local adaptation, and indicate the utility of DNA methylation as a marker for investigating adaptive divergence. Author Keywords: Ecological Epigenetics, Ecological Genetics, SDM
Sextual Consent
The purpose of the current study was to explore the relationships between sexting, perceptions of sexual consent, and nonconsensual sexual experiences (NSEs). Participants consisted of 100 community members and 851 undergraduate students enrolled at Trent University. It was found that males were more likely than females to interpret ambiguous sexual scenarios as consensual, but consent perceptions were not influenced by sexting. When examining past personal experiences, males interpreted received sext messages as an indicator of consent significantly more than females, while females were more likely to interpret received messages as more harassing. NSEs were significantly related to sexting behaviours: those who engage in sexting were more likely to also have experienced a NSE, and 20.5% of participants in the current study reported having experienced a NSE with a consensual sexting partner. The current study has important implications for the future of sexting research, practice, and policy. Author Keywords: nonconsensual sexual experiences, sexting, sexual assault, sexual consent, sexual harassment
Psychometric Properties of a Scale Developed from a Three-Factor Model of Social Competency
While existing models of emotional intelligence (EI) generally recognize the importance of social competencies (SC), there is a tendency in the literature to narrow the focus to competencies that pertain to the self. Given the experiential and perceptual differences between self- vs. other-oriented emotional abilities, this is an important limitation of existing EI models and assessment tools. This thesis explores the psychometric properties of a multidimensional model for SC. Chapter 1 describes the evolution of work on SCs in modern psychology and describes the multidimensional model of SC under review. Chapter 2 replicates this model across a variety of samples and explores the model’s construct validity via basic personality and EI constructs. Chapter 3 further explores the predictive validity of the SC measure within a group of project managers and several success and wellness variables. Chapter 4 examines potential applications for the model and suggestions for further research. Author Keywords: emotional intelligence, project management, social competency, work readiness
cis-Cytokinins from the tRNA-degradation pathway impact the phenotype and metabolome of Arabidopsis thaliana
Cis-isomers of the cytokinin plant hormone family are thought to have low activity or impact on plant growth and development. Mutants with independent silencing of the pathway leading to cis-CK (cis-cytokinin) were investigated at the phenotype and metabolite levels. Phenotypic deviations were noted in trichome development, fresh weight, rosette diameter, number of non-rosette leaves, shoot height, delayed flowering, flower number, and carotenoids. Exploratory metabolomic analysis detected a number of metabolite features that have been associated with CK, auxin, and ABA (abscisic acid) activity. Evidence from both phenotype and metabolomic analysis support the hypothesis that cis-CK production is biologically important for plant growth and development. Author Keywords: arabidopsis, cytokinin, IPT, metabolmics
spatial and temporal distribution of tabanid (Chrysops, Hybomitra and Tabanus) species in the Nakina district of northwestern Ontario
This thesis focused on expanding knowledge of Hybomitra, Chrysops and Tabanus (Diptera: Tabanidae) distributions north of Lake Nipigon, Ontario, in a managed boreal forest. As land use and climate changes accelerate, there is increased pressure to increase knowledge from which to monitor changes. In 2011 and 2012, 8928 individuals representing, 44 species were captured using sweep netting. Major northward range extensions were observed for Chrysops shermani, C. aberrans and Tabanus fairchildi. Smaller range extensions and in-fills were observed for another 15 species. 23 species had exntensions to their previously known seasonal range. C. carbonarius was the only species that showed an extension to both sides of its season. In general, harvested stands had 50% more individuals and 30% greater species richness than younger stands. A possible link between stand age and interspecific competition was identified. Information has been provided to build baseline of species richness, relative abundance and distribution of Tabanid flies. Author Keywords: diptera, distribution, natural history, northern Ontario, species range, tabanid
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
Cloud Versus Bare Metal
A comparison of two high performance computing clusters running on AWS and Sharcnet was done to determine which scenarios yield the best performance. Algorithm complexity ranged from O (n) to O (n3). Data sizes ranged from 195 KB to 2 GB. The Sharcnet hardware consisted of Intel E5-2683 and Intel E7-4850 processors with memory sizes ranging from 256 GB to 3072 GB. On AWS, C4.8xlarge instances were used, which run on Intel Xeon E5-2666 processors with 60 GB per instance. AWS was able to launch jobs immediately regardless of job size. The only limiting factors on AWS were algorithm complexity and memory usage, suggesting a memory bottleneck. Sharcnet had the best performance but could be hampered by the job scheduler. In conclusion, Sharcnet is best used when the algorithm is complex and has high memory usage. AWS is best used when immediate processing is required. Author Keywords: AWS, cloud, HPC, parallelism, Sharcnet
Assessing Connectivity of Protected Area Networks and the Role of Private Lands in the United States
Forestalling biodiversity loss through the establishment of protected areas is a universally accepted conservation strategy, yet despite established guidelines for protected area coverage and placement, much of the world is currently failing to meet its commitments to conservation planning and landscape protection. Calls for the United States to protect more land usually focus on the need for strategic selection of land parcels to bolster protected area coverage and network functionality, but to date there lacks focused research on either the role of private protected areas in conservation planning or the factors affecting individual protected area selection and importance. We determined gaps in conservation planning in the contiguous United States by analyzing the connectivity of protected area networks by state, and assessing the importance of private protected areas in improving linkages in protected area connectivity. We found that all states had low coverage from protected areas (average <8.4% of total land mass), and especially private protected areas (average <1.1% of total land mass), and that the overall contribution of such areas to protected area network connectivity also was low. Terrain ruggedness was identified as the main factor affecting the current location of protected areas, and that protected area spatial layout is a primary influence on landscape connectivity. We conclude that establishment of private protected areas could offer a viable conservation tool for increasing protected area coverage and connectivity, but that current efforts are inadequate to either adequately link existing protected areas or to meet established land protection guidelines. Author Keywords: Aichi Target 11, conservation planning, graph theory, network theory, private conservation, protected areas
Executive Function, Emotion Regulation, and Social Problem Solving, in Adolescence and Early Adulthood
Research to date on social problem solving typically focuses on elementary school aged children. However, adolescents and young adults may experience more novel and emotionally complex social conflicts that require different skills to navigate them successfully. Previous research has highlighted executive function (EF) and emotion regulation as possible skills that help with social problem solving. The current study examined the potential relation between EF, emotion regulation, and social problem solving. The sample consisted of 174 participants with a mean age of 19.60 years. Results showed that the shifting component of EF was associated with being able to take different perspectives when coming up with a solution for a social conflict involving a romantic partner. Additionally, emotion regulation was associate with perspective taking in the overall social problem solving process with a romantic partner. These results suggest that both EF and emotion regulation are involved in the ability to take different perspectives during a social conflict in this age range. Author Keywords: Emotion Regulation, Executive Function, Social Problem Solving
Gratitude is in our nature
Although a wealth of research supports nature’s beneficial effects on well-being, a lack of attentiveness and appreciation for nature may prevent people from fully experiencing nature’s benefits. A mindfulness-based nature intervention was tested across two studies to investigate whether gratitude and mindfulness can boost nature’s effects for well-being. Students completed activities across a one-week (Study 1; N = 129) and two-week (Study 2; N = 130) intervention. Students in both studies experienced significant declines in positive and negative emotion over time. Study 1 did not show the expected increases in gratitude and connection to nature. Study 2 found that students who simply spent time in nature experienced fewer negative emotions and greater increases in trait gratitude than those who were asked to gratefully reflect on their natural surroundings. Both studies found positive correlations between trait gratitude, mindfulness, well- being and connection to nature. Implications and suggestions for future research are discussed. Author Keywords: Gratitude, Intervention, Mental Heath, Mindfulness, Nature, Well-being

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Format: 2024/02/22