- Collections Home
- Alumni House Collection
- Arthur Virtual Archive
- Faculty Research Collection
- Journal GenObs
- Margaret Laurence Collection
- Stories of Resistance, Resurgence, and Resilience in Nogojiwanong / Peterborough
- Trent Community Research Centre Project Collection
- Trent University Academic Calendar Collection
- Trent University Archives
- Trent University Graduate Thesis Collection
- University Heritage Collection
Graduate Theses & Dissertations
Pages
-
- Predictive Digital Mapping of Soils in Kitimat, British Columbia
- Soil is an essential natural resource that supports provisioning services such as agriculture, silviculture, and mining. However, there is limited knowledge on forest soil properties across Canada. Digital soil mapping may be used to fill these data gaps, as it can predict soil properties in areas with limited observations. The focus of this study was to develop predictive maps of select soil physicochemical properties for the Kitimat Valley, British Columbia, and apply these maps to assess the potential impacts of sulphur dioxide emissions from an aluminum smelter, on soil properties in the Valley. Exchangeable [Ex.] magnesium, organic matter, pH, coarse fragment, Ex. potassium, bulk density, Ex. calcium, Ex. acidity, and Ex. sodium were all mapped with acceptable confidence. Time to depletion of base cation pools showed that ~240 km2 of the study area had a depletion time of 50 years or less. However, sources of base cations such as atmospheric deposition and mineral weathering were not considered. Author Keywords: acidification, buffering capacity, Digital soil mapping, predictive mapping, regression kriging, soil properties
-
- 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
-
- Application of One-factor Models for Prices of Crops and Option Pricing Process
- This thesis is intended to support dependent-on-crops farmers to hedge the price risks of their crops. Firstly, we applied one-factor model, which incorporated a deterministic function and a stochastic process, to predict the future prices of crops (soybean). A discrete form was employed for one-month-ahead prediction. For general prediction, de-trending and de-cyclicality were used to remove the deterministic function. Three candidate stochastic differential equations (SDEs) were chosen to simulate the stochastic process; they are mean-reverting Ornstein-Uhlenbeck (OU) process, OU process with zero mean, and Brownian motion with a drift. Least squares methods and maximum likelihood were used to estimate the parameters. Results indicated that one-factor model worked well for soybean prices. Meanwhile, we provided a two-factor model as an alternative model and it also performed well in this case. In the second main part, a zero-cost option package was introduced and we theoretically analyzed the process of hedging. In the last part, option premiums obtained based on one-factor model could be compared to those obtained from Black-Scholes model, thus we could see the differences and similarities which suggested that the deterministic function especially the cyclicality played an essential role for the soybean price, thus the one-factor model in this case was more suitable than Black-Scholes model for the underlying asset. Author Keywords: Brownian motion, Least Squares Method, Maximum Likelihood Method, One-factor Model, Option Pricing, Ornstein-Uhlenbeck Process
-
- In situ measurements of trace metal species in the Athabasca and Mackenzie Rivers using diffusive gradient in thin films (DGT) devices
- This study assesses the bioavailable metal (Cu, Ni, Zn, Pb) species in the Athabasca-Mackenzie watersheds using diffusive gradient in thin films (DGT) devices. Metal toxicity is not only based on the concentration of metal in natural waters, but also on the nature of metal species. Four main forms in aquatic systems are: free ion, inorganic species, DOM bound (humic) species and metal colloidal species. The free ion and inorganic species and very small humic species are known as DGT-labile species and, are considered to be more bioavailable to micro-organisms due to the size and thus may be toxic to microorganisms. In this study, DGT devices were applied to (1) monitor the DGT-labile metal species in the lower Athabasca River and the Mackenzie River watershed and (2) assess the DGT-labile metal concentrations on temporal and spatial scales. In the lower Athabasca River, comparison between the DGT results and the Windermere Humic Acid Model (WHAM) calculation indicated good agreements for all metals when the precipitated iron(III) hydroxide was assumed as an active binding surface. No significant variations in labile species were found over 2003-2012 (RAMP database) despite the development of oil sands. In the Mackenzie River, no significant difference in DGT-labile metal concentrations and DOC concentrations was found in yearly basis 2012-2014. Only DOC was lower in August (6.98 and 3.85 ppm, respectively; p< 0.05) due to dilution from heavy rain events. Spatially, DGT-labile Cu and Ni in the downstream Mackenzie River were higher than upstream (1.79 and 0.58 ppb for Cu, 1.68 and 0.77 ppb for Ni, 4.06 and 6.91 ppm for DOC; p < 0.05). Overall the in situ measurements of metals constitute a benchmark for future studies in water quality and be helpful in environmental management in Alberta and the Northwest Territories in Canada. Author Keywords: Athabasca River, DGT, Mackenzie River, Speciation, Trace Metal, WHAM
-
- 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
-
- Sexual consent
- How one identifies their nonconsensual sexual experiences (NSE) and cognitively integrates the experience into their sexual schemas may affect how individuals perceive and negotiate sexual consent. Previous research has demonstrated that both the method of quantifying NSEs and the labels used to describe NSEs yield different results in psychosexual outcomes associated with NSEs. The current study assessed differences in subjectively and behaviourally quantified NSEs, as well as the role of cognitive and affective appraisals of sexuality and sexual interactions, on sexual consent attitudes. While behaviourally measured NSE history did not significantly influence sexual consent attitudes, the subjective identification of NSEs with various labels did influence attitudes toward sexual consent. Cognitive appraisals of rape and affective appraisals of sexuality also significantly predicted sexual consent attitudes. Implications for future research and NSE prevention are discussed. Keywords: Nonconsensual sexual experiences, sexual consent, quantifying NSEs, affective sexuality, cognitive sexuality Author Keywords: identification, nonconsensual sexual experiences, rape, sexual affectivity, sexual assault, sexual consent
-
- Investigating Ecological Niche Differentiation Among Wild Candids Experiencing Hybridization in Eastern North America
- Currently there are large areas of the North American landscape that are occupied by Canis spp. hybrids of several varieties, leading to the logical question as to the genetic structure and ecological function of Canis populations across the continent, and to what extent hybrids reflect contemporary landscapes. This study illustrated patterns of niche differentiation between parental canid species and their hybrids using individual high quality genetic profile and species distribution models to support the intermediate phenotype hypothesis. In general, hybrids demonstrated an intermediate habitat suitability compared to its parental species, across most environmental variables used. A similar trend was observed in the niche metric analysis, where we found that hybrids exhibit intermediate niche breadth, with eastern coyotes and eastern wolves exhibiting the broader and narrower niche, respectively. Our results demonstrate that the intermediate phenotype hypothesis is supported even at a large scale and when involving highly mobile large mammal species. Author Keywords: canid, ecological niche modelling, hybridization, intermediate phenotype, microsatellite genotype, niche differentiation
-
- Tool-use and near-tool effects
- After active tool-use visual stimuli near a tool are processed more quickly and accurately than those farther away from a tool. Can these near-tool effects be modulated by training demands? To investigate this we asked the participants to complete a tool training task followed by a cross-modal interference task. During the training task the participants performed quick and accurate pointing movements to reach a strict or moderate criterion. The results indicated that the strict group made faster movements than the moderate group. During the cross-modal interference task visual distractors were presented along handheld tools in conjunction with vibrotactile stimuli on the hand. No significant compatibility effects were found for visual distractors near the hand or tool tip, and no consistent group differences were found. Our findings demonstrate the importance of using a novel tool during training, and that virtual stimuli may not be effective to elicit near-tool effects. Author Keywords: bimodal neurons, cross-modal interference, near-tool effects, tool training, training demands
-
- Childhood Precursors of Adult Trait Incompleteness
- Previous research has suggested that childhood sensory sensitivity may predict adult obsessive compulsive (OC) behaviours. To date, however, research has not addressed how the separate dimensions – harm avoidance and incompleteness - may influence this relationship or why it exists. The current study used a retrospective design to test a) if sensory sensitivity in childhood predicts trait incompleteness in adulthood, as well as b) if emotion regulation variables mediate this relationship. Questionnaires pertaining to OC dimensions and childhood anxieties were completed independently by 172 undergraduate participants and their primary childhood caregiver. Results showed a linear relationship between sensory sensitivity in childhood and incompleteness in adults. Emotion regulation variables failed to mediate this relationship, although a trend for mediation was present. Additionally, exploratory analysis found perfectionism in childhood to be a predictor of trait incompleteness but not harm avoidance, whereas physical anxieties predicted harm avoidance and not incompleteness. Results are discussed in the context of clinical and theoretical implications. Author Keywords: Distress Tolerance, Harm Avoidance, Incompleteness, Obsessive Compulsive Disorder, Sensory Sensitivity, Symmetry
-
- Comparing Two Tablet-Based Visuomotor Tasks to Standard Laboratory Versions
- The assessment of visuomotor function can provide important information about neurological status. Several visuomotor tasks exist for testing in the laboratory, although attempts to make these tests portable to allow quick and reliable assessment have been limited. We developed an assessment tool using two laboratory visuomotor tests as a tablet application: the double-step task, and an interception task. Performance was assessed by measuring the participants’ ability to reach toward unpredictably moving targets in each task. Response patterns were compared across equipment types to determine if participants were responding similarly to the moving targets in the standard laboratory and the tablet version of the tasks. On the double-step task, participants adjusted to the displaced target adequately in both the lab and tablet versions. On the interception task, participants intercepted non-accelerating targets, and performed worse on accelerating targets in both versions of the task. These findings suggest that the tablet version of these tasks assesses similar visuomotor processing as the respective laboratory version. Author Keywords: concussion assessment, double-step task, interception task, visuomotor processing, visuomotor system
-
- Fathering Experience of the Transition Into Parenthood
- Men who become fathers undergo a transitional period during which they adjust to their new role as the caregiver of a child, a time that is usually viewed as a major life transition (Lamb, 2010). Much of the published literature focuses on fathers with identified issues (e.g., divorced fathers); therefore, there is a need for research that looks at the experiences of more typical fathers in the current Canadian context. To understand how fathers experience this transition, a series of focus groups were conducted with first-time fathers across the Peel Region of Ontario, Canada. Analysis of the focus group transcripts using an interpretative phenomenology framework identified four overarching metathemes: intrapersonal experiences, extrapersonal experiences, father’s role, and supports. Practical implications, theoretical implications, and limitations are discussed. Author Keywords: Fathering, Fathering Experience, First-Time Fathers, Transition Into Parenthood
-
- Marital Satisfaction Throughout the Journey of Weight-Loss Surgery
- A mixed-methods’ approach was designed to explore the marital impacts following weight-loss surgery (WLS). In Phase 1, ten individual interviews with spouses of five couples were conducted; two of the couples had the wives preparing for WLS, two of the couples consisted of wives who had WLS, and one couple had both received the surgery. Interviews were transcribed and analyzed using a combination of interpretive phenomenological and grounded theory techniques. Findings demonstrated that WLS does have impacts on marriage regardless of where couples are in their journey. All couples discussed food as a possible source of conflict in their relationship. Interviews also reveled that self-esteem is a major factor contributing to their relationship and support is necessary throughout. In Phase 2 an online survey was developed to quantitatively explore the important constructs deemed important from the participants in Phase 1. Relationships between relationship satisfaction, sexual conflict, self-esteem, depression and body image were examined in 54 participants. Results demonstrate that higher levels of support and self-esteem and lower sexual conflict relate to a more satisfactory relationship in individuals post- WLS. Author Keywords: marital satsifaction, mixed-methods, qualitative, relationship satisfaction, weight-loss, Weight-loss surgery