Graduate Theses & Dissertations

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Intra-seasonal Variation in Black Tern Nest-site Selection and Survival
Resources and risk are in constant flux and an organism’s ability to manage change may improve their likelihood of persistence. I examined intra-seasonal variation in nest-site selection and survival of a declining wetland bird, the Black Tern (Chlidonias niger surinamensis). I modelled nest site occupancy and survival of early and late-nesting birds as a function of static and dynamic factors. Early-nesting birds selected nest sites based on the degree and direction of habitat change that occurred over the nesting cycle, while late-nesting birds selected sites based on static conditions near the time of nest-site selection. Nest age had the strongest influence on daily survival rate for both early and late-nesting birds, but the shape of this relationship showed intra-seasonal differences. Additionally, early-season survival improved slightly with increasing vegetation coverage and distance between conspecific nests, while late-season survival increased with clutch size. My results suggest that intra-seasonal variation in nest-site selection and survival is driven by changing habitat conditions and predator behavior. Author Keywords: Black Tern, Chlidonias niger surinamensis, daily survival rate, intra-seasonal variation, nest-site selection
Smile and a Neutral Attitude
This thesis examines the ways in which body image is discussed in online settings. There are three different communities discussed: body positivity, proED (pro-eating disorder), and body neutrality. Both body positivity and proED content are fairly popular online, and both have found significant support and followers on various social medias. In this thesis, I argue that both of these types of content cause significant harm to those who engage with them, primarily because both communities (though different in their approaches to body image) work to uphold the thin ideal. I then bring up the third type of content: body neutrality. Body neutrality has not been given the same academic attention as body positivity and proED content, likely due to its relative infancy. In this thesis, I propose body neutrality as a much healthier way to frame body image online because of its completely neutral stance on fat, thinness, and general body image. Though any work relating to social media is quickly out of date, I hope that this thesis provides an overview of body neutrality and how, in its current form, it provides a more balanced approach to online body image discussions. Author Keywords: body image, body neutrality, body positivity, eating disorders, social media
Analyzing agricultural decision making in the Late Roman Empire
In the Roman World, at least 80% and up to 95% of the population lived and worked in a rural environment, driving the agronomic economy of the empire. During the Late Roman Empire (AD 300-600), there were a number of widespread political, social, and economic changes faced by the people who made up the empire. Through all these changes, the empire maintained its tax collection and households maintained agricultural production. I will be examining settlement in the rural region of Isauria (Rough Cilicia) to understand the Late Roman agricultural production in a rural environment. This thesis focuses on the decision making that all economic levels of households would face when producing goods within this Late Roman Economy. Using an economic theory of the peasant economy, I develop a framework through which to view the agronomic production of the Late Roman Period which I use to understand the household as an agent. Author Keywords: Ancient Economy, Isauria, Late Roman, Peasant Economy, Roman Economy
Developing social skills
Guidelines regarding social skills interventions for children with ASD suggest incorporating a holistic approach. This includes increasing the family’s understanding of deficits associated with ASD, integrations of natural environments, and parents as active agents while supporting their well-being. The current availability of holistic parent-mediated interventions for children with ASD is limited, with no qualitative understanding of its potential benefits for either the parent or child. The current study examined qualitative parent reports on a parent-mediated social skills intervention for children with ASD (TalkAbilityTM) incorporating a longitudinal approach (i.e., 6-month follow-up). Following Braun and Clarke’s model of thematic analysis, data was coded into four themes: 1) communication difficulties, frustrations and progress, 2) social relationships and concerns, 3) communication strategies, and 4) thoughts and emotions surrounding TalkAbilityTM. Results highlight the importance of considering parent experiences regarding interventions for their child’s social communication skills through a qualitative viewpoint. Author Keywords: autism spectrum disorder, parent-mediated intervention, qualitative review
SPATIAL AND TEMPORAL GENETIC STRUCTURE OF WOLVERINE POPULATIONS
Habitat loss and fragmentation can disrupt population connectivity, resulting in small, isolated populations and low genetic variability. Understanding connectivity patterns in space and time is critical in conservation and management planning, especially for wide-ranging species in northern latitudes where habitats are becoming increasingly fragmented. Wolverines (Gulo gulo) share similar life history traits observed in large-sized carnivores, and their low resiliency to disturbances limits wolverine persistence in modified or fragmented landscapes - making them a good indicator species for habitat connectivity. In this thesis, I used neutral microsatellite and mitochondrial DNA markers to investigate genetic connectivity patterns of wolverines for different temporal and spatial scales. Population genetic analyses of individuals from North America suggested wolverines west of James Bay in Canada are structured into two contemporary genetic clusters: an extant cluster at the eastern periphery of Manitoba and Ontario, and a northwestern core cluster. Haplotypic composition, however, suggested longstanding differences between the extant eastern periphery and northwestern core clusters. Phylogeographic analyses across the wolverine's Holarctic distribution supported a postglacial expansion from a glacial refugium near Beringia. Although Approximate Bayesian computations suggested a west-to-east stepping-stone divergence pattern across North America, a mismatch distribution indicated a historic bottleneck event approximately 400 generations ago likely influenced present-day patterns of haplotype distribution. I also used an individual-based genetic distance measure to identify landscape features potentially influencing pairwise genetic distances of wolverines in Manitoba and Ontario. Road density and mean spring snow cover were positively associated with genetic distances. Road density was associated with female genetic distance, while spring snow cover variance was associated with male genetic distance. My findings suggest that northward expanding anthropogenic disturbances have the potential to affect genetic connectivity. Overall, my findings suggest that (1) peripheral populations can harbour genetic variants not observed in core populations - increasing species genetic diversity; (2) historic bottlenecks can alter the genetic signature of glacial refugia, resulting in a disjunct distribution of unique genetic variants among contemporary populations; (3) increased temporal resolution of the individual-based genetic distance measure can help identify landscape features associated with genetic connectivity within a population, which may disrupt landscape connectivity. Author Keywords: conservation genetics, Holarctic species, landscape genetics, peripheral population, phylogeography, wolverine
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
Novel Silica Sol-Gel Passive Sampler for Mercury Monitoring in Aqueous Systems
A novel passive sampler for mercury monitoring was prepared using organosilica sol-gel materials. It comprises a binding layer with thiol groups for mercury complexation and a porous diffusive layer through which mercury can diffuse and arrive at the binding layer. Our study demonstrated that this new sampler follows the principle of passive sampling. The mass of mercury accumulated in the binding layer depends linearly on the mercury concentration in solution, the sampling rate and the exposure time. A typical sol-gel sampler is characterized by a diffusive layer of 1.2 &mum, in which mercury ions diffuse with a coefficient of D = 0.09~10-6 cm2/s. The capacity for mercury uptake is approximately 0.64 &mug/cm2. Mercury diffusion and binding in the passive sampler are independent of the type of mercury-chloride complex. Its sampling rate increases with increasing water turbulence and decreases with increasing DOM amount. The field trial of sol-gel sampler in Miller Creek shows the concentration gained from the sol-gel passive sampler is slightly lower than that from the spot sampling. Author Keywords:
Time Series Algorithms in Machine Learning - A Graph Approach to Multivariate Forecasting
Forecasting future values of time series has long been a field with many and varied applications, from climate and weather forecasting to stock prediction and economic planning to the control of industrial processes. Many of these problems involve not only a single time series but many simultaneous series which may influence each other. This thesis provides methods based on machine learning of handling such problems. We first consider single time series with both single and multiple features. We review the algorithms and unique challenges involved in applying machine learning to time series. Many machine learning algorithms when used for regression are designed to produce a single output value for each timestamp of interest with no measure of confidence; however, evaluating the uncertainty of the predictions is an important component for practical forecasting. We therefore discuss methods of constructing uncertainty estimates in the form of prediction intervals for each prediction. Stability over long time horizons is also a concern for these algorithms as recursion is a common method used to generate predictions over long time intervals. To address this, we present methods of maintaining stability in the forecast even over large time horizons. These methods are applied to an electricity forecasting problem where we demonstrate the effectiveness for support vector machines, neural networks and gradient boosted trees. We next consider spatiotemporal problems, which consist of multiple interlinked time series, each of which may contain multiple features. We represent these problems using graphs, allowing us to learn relationships using graph neural networks. Existing methods of doing this generally make use of separate time and spatial (graph) layers, or simply replace operations in temporal layers with graph operations. We show that these approaches have difficulty learning relationships that contain time lags of several time steps. To address this, we propose a new layer inspired by the long-short term memory (LSTM) recurrent neural network which adds a distinct memory state dedicated to learning graph relationships while keeping the original memory state. This allows the model to consider temporally distant events at other nodes without affecting its ability to model long-term relationships at a single node. We show that this model is capable of learning the long-term patterns that existing models struggle with. We then apply this model to a number of real-world bike-share and traffic datasets where we observe improved performance when compared to other models with similar numbers of parameters. Author Keywords: forecasting, graph neural network, LSTM, machine learning, neural network, time series
Positive Solutions for Boundary Value Problems of Second Order Ordinary Differential Equations
In this thesis, we study modelling with non-linear ordinary differential equations, and the existence of positive solutions for Boundary Value Problems (BVPs). These problems have wide applications in many areas. The focus is on the extensions of previous work done on non-linear second-order differential equations with boundary conditions involving first-order derivative. The contribution of this thesis has four folds. First, using a fixed point theorem on order intervals, the existence of a positive solution on an interval for a non-local boundary value problem is obtained. Second, considering a different boundary value problem that consists of the first-order derivative in the non-linear term, an increasing solution is obtained by applying the Krasnoselskii-Guo fixed point theorem. Third, the existence of two solutions, one solution and no solution for a BVP is proved by using fixed point index and iteration methods. Last, the results of Green's function unify some methods in studying the existence of positive solutions for BVPs of nonlinear differential equations. Examples are presented to illustrate the applications of our results. Author Keywords: Banach Space, Boundary Value Problems, Differential Equations, Fixed Point, Norm, Positive Solutions
Breach, Digital Disruption, the Event
The goal of this dissertation is to formulate a critique of embodiment through the lens of Lacanian psychoanalysis and in the context of digital media and intelligent technologies. Along with psychoanalysis, our research methodology and philosophy are informed by Badiou’s philosophy of the event, Stiegler’s philosophy of technics and infrastructuralism in media studies. Our study aims to uncover and articulate the implicit conditioning by the primordial trauma constitutive of the subject’s encounters with the medium. In our analysis of embodiment, we make extensive use of psychoanalytic concepts such as: the breach, the lack, the signifier, the construction of the object, the object-a, the transitional object, fetishism and phobia. Each of the four parts of the dissertation approaches the topic from a specific angle, such as the theoretical critique of the basic concepts of the subject and object, the function of the metaphor in the context of intelligent technologies, the role of technological infrastructure in the embodiment of the trauma, the construction of a transitional object such as a pop song in the context of technological dystopianism. We demonstrate that the cognitivist presumption concerning the pivotal role of intellectual motivation behind the subjective attachment to information technologies can be significantly shaken from the point of view of the psychoanalytic understanding of drives and jouissance. On the basis of Alain Badiou’s argument, we show the limitations of structurally-determined forms of embodiment considered by psychoanalysis and draw a dividing line between them and the more rare cases of the subjectivation by events suggested by Badiou’s theory. We discuss Badiou’s concept of the work of truth as an advanced alternative to the psychoanalytic concept of the object and the paradigm of the construction of the (transitional) object. We distinguish the Badiouian concept of the event from the idea of technological/digital disruption, on the one hand, and correlate the latter with the problems discussed in psychoanalysis such as the foreclosure of the Name-of-the-Father and the crisis of the paternal metaphor along with the problems of the futurity and the disruption of intergenerational communication discussed by Bernard Stiegler on the other. Author Keywords: Badiou, digital media, Lacan, metaphor, transitional object, work of truth
Emotional Competencies in Mothers and Children and their Relationship with Health Care Utilization, Somatization and Health Anxiety.
Young children learn their emotion regulation skills by modeling and internalizing their caregivers' emotional competencies. Inadequate or problematic emotional competencies in parents can result in insufficient development of these competencies in children, which can have severe consequences on multiple domains of their lives, including physical wellbeing. This study examined the relationship between emotional competencies, health care usage rates, somatization and health anxiety in the context of a family with young children. Participants were mothers of children 4-11 years old recruited in the community. The results revealed a relationship between mother’s emotional competencies and mother and child’s health care usage rates. Mother’s health care usage rates were also linked to mother’s health anxiety and child’s somatic symptoms. These findings add to our understanding of the relationship between emotional competencies of parents and children, and the effects it can have on both mother’s and child’s physical wellbeing. Implications and avenues for future research are discussed. Author Keywords: emotional competencies, health care usage, mother and child, somatization
Virtual Voices
A consistent provincial approach to capacity planning for rehabilitative care had been identified as a critical gap in the field of health care in Ontario (Rehabilitative Care Alliance, 2015a). In response, the rehabilitative care alliance (RCA) developed a needs based hip fracture capacity planning canvas together with persons and families. This research utilized computer assisted participation (CAP) to gather additional perspectives from Virtual Voices via an on-line survey. The results of the Virtual Voices survey were compared to Ontario’s RCA hip fracture patient focus group findings. CAP facilitated more voices and more ideas through virtual engagement. The survey method required 97% (10.6 hours) less time than the focus group. The Virtual Voices respondents provided validation of the focus groups’ confirmation of the rehabilitative care needs, locations and most core team members as well as identified new ideas. The results support the implementation of a needs-based capacity plan that enables individualized care planning. This research provides a blueprint for the ongoing engagement of persons and families in the co-creation of a sustainable rehabilitative care system. A dashboard and e-health app would enable ongoing co-design, monitoring and evaluation. Author Keywords: Computer Assisted Participation (CAP), Computer Assisted Survey, Hip Fracture, Rehabilitative Care Needs, Virtual Collaboration, Virtual Engagement

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Format: 2024/03/19