Graduate Theses & Dissertations

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Comparison of the Optical Properties of Stratiotes aloids and the Local Plant Community
As part of a mandate to control the spread of Stratiotes aloides (WS; water soldier) in the Trent Severn Waterway, the Ministry of Natural Resources (MNR) created a management plan to eradicate WS. However, one of the biggest challenges in eradicating WS or any invasive aquatic plant is the ability to estimate the extent of its spread and detect new populations. While current detection methods can provide acceptable detection, these methods often require extensive time and effort. The purpose of this thesis was to assess the use optical properties of WS and WS exudates for detection, in order to improve on current detection methods. The optical properties of WS were sampled at three different sites during three different seasons (spring, summer, and fall) by a) randomly sampling tissue from WS and the local plant community at each site, and recording the reflectance properties in a laboratory setting b) collecting dissolved organic matter (DOM) samples from plant incubations and river water in the field. Significant differences in the reflectance properties of WS were observed among samples from different sites and different sampling times; however, changes in fluorescence properties were only seasonal. Despite spatial differences in WS reflectance; WS was detectable using both hyperspectral and multispectral reflectance. When hyperspectral reflectance was used, significant differences between WS and the local plant community were found in June using two bands (i.e. bands 525 and 535, R 2 = 0.46 and 0.48, respectively). Whereas multispectral reflectance was significant different in October using the coastal and blue band. While WS produced a unique signal using both reflectance types, multispectral reflectance had a greater potential for detection. Its greater potential for detection was due to the reduced noise produced by background optical properties in October in comparison to June. DOM derived from WS was also characterized and compared with whole-river DOM samples in order to find unique markers for WS exudates in river samples. While similarities in DOM concentrations of WS exudates to Trent River water limited the ability to detect WS using compositional data, the ratio of C4/C5 components were compared in order to find components that were proportionally similar. Based on the results of this study multispectral and fluorescence techniques are better suited for the detection of a unique WS signature. The results derived from this work are intended to have practical applications in plant management and monitoring, DOM tracing, as well as remote sensing. Author Keywords: Dissolved organic matter, Hyperspectral reflectance, Invasive species management, Multispectral reflectance, PARAFAC, Stratiotes aloides
Developing a Sustainable Resort
Sustainability-related issues have been drawing considerable attention in the resort and hotel industry. This research explores the meaning of a “sustainable resort” and to identify the opportunities and challenges of developing a “sustainable resort” as well as the opportunities and challenges of engaging employees in this process, through a case study of a family resort in Central Ontario, Canada. A significant finding is that a “sustainable resort” in the context of a family business highlights cultural sustainability, which emphasizes on keeping family roots and passing on family legacy, as well as addresses economic, social, and environmental sustainability. The nature of the selected case, a traditional family resort, provides some valuable insights on the issues of sustainability and employee engagement in the resort and hotel industry. To improve sustainable outcomes for the resort, a holistic approach of collaborating with different key stakeholders, particularly emphasizing employee engagement as a core strategy, is proposed. Author Keywords: employee engagement, family resort, resort and hotel industry, sustainability, sustainable development
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
Building Individuals, Building the Economy
This thesis explores the neoliberal governmentality approach to education for Northern economic development that was prevalent from 2006 to 2015, during Stephen Harper’s period as Prime Minister of Canada. Using a grounded theory approach, this thesis identifies three themes – Indigenous integration, education, and employment for labour force/ economic development – to direct an analysis on programs and funding supported by the Canadian Northern Economic Development Agency, Employment and Social Development Canada, and Indigenous and Northern Affairs Canada. This examination suggests that Federal programming and funding encouraged neoliberal governmentality approaches to Northern development and education. Specifically, the former Government interest in developing an Indigenous work force to serve labour market needs is brought to light. Author Keywords: Economic Development, Indigenous Education, Labour Force Development, Neoliberalism, Territorial North
Electrochemical Characterization of Giardia Intestinalis Cytochromes b5
Giardia intestinalis is a protozoan parasite that causes waterborne diarrheal disease in animals and humans. It is an unusual eukaryote as it lacks the capacity for heme biosynthesis; nonetheless it encodes heme proteins, including three cytochrome b5 isotypes (gCYTB5s) of similar size. Homology modelling of their structures predicts increased heme pocket polarity compared to mammalian isotypes, which would favour the oxidized state and lower their reduction potentials (E°’). This was confirmed by spectroelectrochemical experiments, which measured E°’ of -171 mV, -140 mV and -157 mV for gCYTB5-I, II, III respectively, compared to +7 mV for bovine microsomal cytochrome b5. To explore the influence of heme pocket polarity in more detail, five gCYTB5-I mutants in which polar residues were replaced by nonpolar residues at one of three positions were investigated. While these substitutions all increased the reduction potential, replacement of a conserved tyrosine residue at position-61 with phenylalanine had the most significant effect, raising E°’ by 106 mV. This tyrosine residue occurs in all gCYTB5s and is likely the greatest contributor to their low reduction potentials. Finally, complementary substitutions were made into a bovine microsomal cytochrome b5 triple mutant to lower its reduction potential. These not only lowered the E°’ by more than 140 mV but also weakened the interaction of heme with the protein. The lower reduction potentials of the gCYTB5s may indicate that these proteins have different roles from their more well-known mammalian counterparts. Author Keywords:
evolutionary ecology of Alaska's mountain goats with management implications
The integration of genetic and environmental information can help wildlife managers better understand the factors affecting a species’ population structure and their response to disturbance. This thesis uses genetic techniques to assess the broad and fine scale population structure of mountain goats in Alaska. The first chapter aims to determine the number of genetically distinct subpopulations and model the demographic history of mountain goats in Alaska. The second chapter investigates the population structure and demographic history of mountain goats in Glacier Bay National Park and examines the impact that climate change will have on these mountain goats. My results indicate that Alaska has eight subpopulations which diverged during the Wisconsin glaciation. In Glacier Bay, population structure is reflective of the landscape during colonization, and mountain goat population density and movement corridors are likely to decline due to future climate change. Author Keywords: Alaska, biogeography, gene flow, landscape genetics, mountain goat, population genetic structure
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
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
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
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
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
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:

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Format: 2024/04/16