Arts and Science, Faculty of

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    1H NMR metabolomics of stress
    (Lethbridge, Alta : University of Lethbridge, Dept. of Neuroscience, 2016) Kiss, Douglas A.; University of Lethbridge. Faculty of Arts and Science; Metz, Gerlinde A. S.
    Metabolomics provides a method to study the dynamics of cellular function by adopting a systems biology approach to the analysis of small molecule metabolites found in various bio-fluids and tissue locations. Chapters one and two of this thesis explore the theory behind metabolomics and reviews representative studies applying NMR metabolomics to neuroscience. Chapter three presents the results from an experiment investigating the alterations of metabolic by-products found in urine caused by both cumulative and remote ancestral prenatal maternal stress. Chapter four explores the results of a similar experiment where the liver tissue from offspring of either cumulative or remote ancestral prenatal maternal stress were analysed. Chapter five is a general discussion and conclusion of the results from both experiments and explores how both sets of results indicate an alteration in the stress response of the offspring.
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    3D biomechanical quantification of piano motor skills
    (Lethbridge, Alta. : University of Lethbridge, Dept. of Kinesiology and Physical Education, 2021) Turner, Craig Patrick; University of Lethbridge. Faculty of Arts and Science; Shan, Gongbing; Visentin, Peter
    To date, systematic biomechanical explorations of music performance have been scarce. In many human activities, movement science methodologies have helped accelerate the learning process, prevent injuries, improve teaching practices, and optimize performance outcomes. The current thesis postulates that a consideration of individualization with respect to biomechanics, anthropometry, and musical strategization can provide musicians with an approach to motor learning where outcomes may be optimized while simultaneously reducing risk of playing-related injury. The thesis is comprised of three case comparison studies using 3D motion capture, biomechanical modeling, and force plate measurements to quantify pianists’ motor behaviours in a variety of performance contexts. The framework established in the thesis is interdisciplinary and provides a model that aims to be “artful” in its efforts to ensure that its analyses of motor behaviours are sensitive to musical intentionality and, thus, can be relevant to musicians.
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    8,893 kilometres of cooperation : applying Kingdon's model to the development of Canadian border security policy since 9/11
    (Lethbridge, Alta. : University of Lethbridge, Dept. of Political Science, c2009, 2009) Marcotte, Christina; University of Lethbridge. Faculty of Arts and Science; Hale, Geoffrey
    Canadian border security policies are largely shaped by the asymmetrical relationship that exists between Canada and the United States. American markets are the primary destination for over eighty percent of Canadian exports, creating an economic dependence highlighted in the days following 9/11. As wait times at the American border extended to sixteen hours the importance of the shared border came sharply into focus. To ensure Canada‟s economic security the Canadian government needed to develop policies that would satisfy the American need for physical security and the Canadian need for economic security. This thesis applies John Kingdon‟s policy streams model to demonstrate and explain the subsequent development of Canadian border security policies. It also examines the institutional context for border security policies and examines two case studies: the Container Security Initiative and NEXUS.
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    A comparative study of augmented features and other ensemble approaches for music genre classification
    (Lethbridge, Alta. : University of Lethbridge, Dept. of Mathematics and Computer Science, 2023) Shariat, Raad; University of Lethbridge. Faculty of Arts and Science; Zhang, John Z.; Kharaghani, Hadi
    Music genre classification is essential in the music streaming industry, with many recommendation systems relying on data mining techniques to accurately classify musical genres. However, classifying music genres is challenging due to the inherent diversity of music, even within a single genre. This diversity can make it difficult for machine learning models to classify music accurately, leading to the development of various techniques to improve the performance of these models. One such technique is ensemble learning, which combines the predictions of multiple models to improve the overall accuracy of the ensemble. In this thesis, we propose a new ensemble method called "Augmented Features," which combines the predictions of multiple models by augmenting the input features with additional derived features. This technique can improve the performance of ensemble models by providing additional information to the models, allowing them to capture the music data's complexity better. To evaluate the performance of our ensemble method, we conducted experiments on various music datasets combined with different feature selection techniques. We compared the results to those obtained using the base classifiers and other ensemble methods, including voting, blending, and stacking. Our results showed that the augmented features method repeatedly outperformed the different techniques, particularly on datasets with high dimensionality and complex relationships between features. It is hoped that this work will significantly contribute to ensemble methods and improve the performance of machine learning models in various applications.
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    A comparative study of the impact of education on economic growth in 49 selected developing countries
    (Lethbridge, Alta. : University of Lethbridge, Dept. of Economics, 2023) Islam, Syeda Arowah; University of Lethbridge. Faculty of Arts and Science; Rockerbie, Duane
    This paper estimates the potential impact of human capital, proxied by government expenditures on education, on economic growth. A panel data regression analysis is employed to investigate this association, utilizing yearly data from 2005 to 2010 across 49 selected developing countries. The regression model employs fixed effects and random effects and includes corrections for panel heteroskedasticity and serial correlation. A vector of other independent variables is utilized to account for other factors that could affect GDP growth based on those suggested by other studies. The fixed effects results suggest a positive but statistically insignificant relationship between government expenditure on education and GDP growth (annual %). Conversely, the random effects results suggest an insignificant negative relationship between government expenditure on education and GDP growth (annual %). These results raise questions regarding the productive utilization of education within society and prompt further inquiries into the efficiency of education in developing countries.
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    A computational model of Blackfoot noun and verb morphology
    (Lethbridge, Alta. : University of Lethbridge, Dept. of Indigenous Studies, 2023) Kadlec, Dominik Miroslav; University of Lethbridge. Faculty of Arts and Science; Genee, Inge; Arppe, Antti
    This thesis describes the construction of a computational model of Blackfoot word structure. This model was developed so that it could provide a foundation for Blackfoot language technologies such as spelling and grammar checkers, search suggestion generators, paradigm generators for pedagogical purposes, intelligent dictionaries, automated corpus parsers for linguistic research and more. Many Indigenous languages in Canada have been declining in use. In response, many Indigenous communities and activists have implemented revitalization strategies which vary in effectiveness. One way to help language efforts to be more effective is to ensure that tools for research and revitalization are freely available to community members. In the 21st century this can be achieved in part through technology, particularly with the help of the internet, which offers information freely (in most cases) to those who wish to access it. In this thesis I describe the early developments of a project that will be used to augment currently available digital resources and provide a basis for future technology for the Blackfoot language. I use Finite State Transducer technology to develop a computational model of Blackfoot noun and verb morphology and test the model using a corpus of modern Blackfoot text that was constructed from a curated collection of available texts.
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    A cryogenic multiaxis range-resolved laser interferometer
    (Lethbridge, Alta. : University of Lethbridge, Dept. of Physics and Astronomy, 2023) Christiansen, Adam J.; University of Lethbridge. Faculty of Arts and Science; Naylor, David
    Building upon the successes of previous far-infrared space astronomy missions that initially featured small but cold (<4 K) or large but warm telescopes, the future path is clear: the next generation of far-infrared telescopes must be both large and cold, which requires cryogenic cooling of the mirrors, instrumentation, and detectors. The precision to which the moving cryogenic components of the instrument must be measured and controlled demands a robust low power position metrology system, and a cryogenic multiaxis range-resolved laser interferometer using a sinusoidal frequency modulation (SFM) technique was investigated to solve this problem. The development included cryogenic considerations and characterization of several fibre and optical components, calibration of the selected hardware, and verification of the technique. Simultaneous multiaxis measurements were demonstrated at ambient and cryogenic temperatures of <6 K, and the measured performance under ambient conditions showed a resolution of ~50 pm and a stability of 0.4 nm rms in a 20 Hz bandwidth. The demonstrated performance exceeds that which is required by proposed far-infrared missions and distinguishes the SFM range-resolved laser interferometer as a leading candidate for future space-based applications.
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    A day in the life of Mus musculus: homecage behavioural analysis of a mouse model of Alzheimer disease
    (Lethbridge, Alta. : University of Lethbridge, Dept. of Neuroscience, 2023) Liang, Jiajie; University of Lethbridge. Faculty of Arts and Science; Mohajerani, Majid H.; Cheng, Howard
    Traditionally, behavioural research of Alzheimer disease animal models involved specialized experiments that require dedicated apparatus and presence of experimenter. However, experiment apparatus and the interaction between animals and experimenters can influence the behaviours of the animals, and result in difficulty in reproducibility. One recent innovation is to study behaviours of Alzheimer disease mouse model in their homecages. This thesis presents an experiment using automated homecages to observe the homecage behaviours of 5xFAD mouse models over 26 weeks. By measuring daily activity level, circadian rhythm and excursion behaviours, the experiment successfully produces measurements consistent with prior knowledge and provides some further insight in the behaviours of the mouse model. This thesis validates the approach using homecage behaviours as a paradigm for AD animal research.
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    A feminist approach to a theory of dehumanization: evaluating dehumanization of women in contemporary digital social environments
    (Lethbridge, Alta. : University of Lethbridge, Dept. of Philosophy, 2024) Newman, Jodi N.; University of Lethbridge. Faculty of Arts and Science; Stingl, Michael
    Dehumanization has facilitated the worst atrocities in humanity’s historical record and continues to facilitate some of the gravest cruelties in the world today. While there is substantial work on dehumanization within philosophical and scientific disciplines, there remains an incongruence within the theoretical conceptualizations of dehumanization leading to the neglect or denial of the dehumanization of women. Some contend that dehumanization most characteristically occurs between racial or ethnic groups, but dehumanization may be a more general and deeply embedded aspect of human nature, more robust and perilous in its potential to victimize any member of a distinct group, even where group memberships might otherwise overlap with one another in more affiliative ways. As our social environments are evolving in lockstep with our communication technologies, the recognition of and response to the dehumanization of women remains inadequate and morally inexcusable.
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    A mixed-method study on understanding irregular migration to Canada through technology-mediated communication: YouTube as a case study
    (Lethbridge, Alta. : University of Lethbridge, Dept. of Geography and Environment, 2023) Nasser, Wael M. A.; University of Lethbridge. Faculty of Arts and Science; Young, Julie
    This study assesses the content, quality, and reliability of YouTube videos about irregular migration to Canada which effect migration decision-making. Using quantitative and qualitative methods, 342 out of 4986 YouTube videos posted between November 2016 and December 2019 were analyzed. The study illustrates the vast array of information available on YouTube on different topics such as transportation to the border, Canadian immigration laws, and basis of refugee claims. The results highlight the need for policymakers and researchers to understand where information is coming from and how potential migrants perceive it. The study examined Canadian government's use of digital spaces, like YouTube, to deter irregular migration and correct misperceptions. The thesis proposes policy recommendations for effective information campaigns on YouTube and proactive monitoring of irregular migration. It also emphasizes the technology sector's significant role in irregular migration to Canada with its implications for both irregular migrants and the Canadian government.
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    A multi-compartment pharmacokinetic model of docetaxel
    (Lethbridge, Alta. : University of Lethbridge, Dept. of Physics and Astronomy, 2023) Kuhn, Alissa J.; University of Lethbridge. Faculty of Arts and Scince; Vos, Kenneth
    Docetaxel is a clinically active chemotherapeutic agent commonly used in the treatment of solid tumors. It is administered within a micelle encapsulation, polysorbate 80, via intravenous infusion. Docetaxel is known to have a high degree of interpatient variability in its pharmacokinetic behaviour. In this work, intensive, quantitative, compartmental pharmacokinetic models of docetaxel and its vehicle polysorbate 80 are developed. These models introduce both saturable kinetics and power-law relationships to the kinetic behaviour of these molecules. When fit to clinical data available in the literature by minimizing the weighted percentage variance these models out perform traditional linear models. A threecompartment model of docetaxel with both saturable and fractal effects is shown to accurately describe docetaxel pharmacokinetics. From this model pharmacokinetic metrics such as the maximum concentration, the area under the curve, and the half-life are derived. The sensitivity of this model’s parameters to interpatient variability is also investigated.
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    A quantum accelerated approach for the central path method in linear programming
    (Lethbridge, Alta. : University of Lethbridge, Dept. of Mathematics and Computer Science, 2023) Adoni, Vijay; University of Lethbridge. Faculty of Arts and Science; Gaur, Daya
    The central path method is a crucial technique used in the optimization of linear programs. The method relies on classical computation which hits its limit for large instances, generally used in practice, in terms of efficiency. In this thesis, a proposal is made to explore the use of quantum algorithms to enhance the central path method’s performance when solving linear programs. We will go through the potential benefits and limitations of replacing the iterative equation-solving step with the HHL quantum algorithm, the Newton’s step for solving a set of nonlinear equations, and converting the nonlinear set of equations to bilinear equations with the help of McCormick relaxations. The aim of this thesis is to perform extensive experimentation on several types of efficient instances using each of the proposed algorithms and to evaluate their effectiveness through numerical simulations to find a promising approach for the central path method.
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    A survey of Büthe's method for estimating prime counting functions
    (Lethbridge, Alta. : University of Lethbridge, Dept. of Mathematics and Computer Science, 2024) Bhattacharjee, Sreerupa; University of Lethbridge. Faculty of Arts and Sciences; Ng, Nathan
    This thesis provides explicit bounds for the Chebyshev prime counting function ψ(x). This thesis aims to produce a detailed survey of the first part (from page 2483 to page 2494) of the paper, ‘Estimating π(x) and Related Functions Under Partial RH Assumptions’ by Jan B ̈uthe published in 2016. His article provides the best-known bounds for ψ(x) for x ≤ e3000 using the Fourier Transform of the Logan Function, assuming the Riemann Hypothesis to be valid for all zeroes of the zeta function with ℑ(ρ) ∈ (0, T ] for a specific T. The main theorem in B ̈uthe’s paper gives a bound for |ψ(x) − x| using an equation with three major terms E1, E2 and E3 and provides bounds for each of these terms individually. The necessary lemmas, propositions and their proofs required to prove the main theorem are scattered throughout various papers such as [7], [8], [10], [18], and [6]. In this thesis, we have accumulated all these results, verified their proofs, and included various missing details. Several of the arguments in the original paper have been reworked, and necessary corrections, such as rectifying the error terms E2 and E3 in the main theorem, and other minor amendments have been made with the goal of turning this thesis into a self-contained research exposition of B ̈uthe’s work in [7].
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    A TTOP model of permafrost distribution in the boreal wetland environment of Whatì, NT, Canada
    (Lethbridge, Alta. : University of Lethbridge, Dept. of Geography, 2023) Vegter, Scott E.; University of Lethbridge. Faculty of Arts and Science; Bonnaventure, Philip
    Most permafrost models in Canadian boreal forests are low resolution at a regional or continental scale. This study aims to understand the viability of a Temperature at Top of Permafrost (TTOP) model on a local scale in the boreal wetland environment of Whatì, N.T. The model utilizes independent variables of vegetation, topographic positioning index and elevation, with the dependent variable being ground surface temperature collected from 60 Ground Truthing Nodes (GTN). The model predicts that 29 % of the ground is underlain by permafrost by having a mean annual temperature of < 0 °C. Model accuracy is assessed at 62.5 % when compared to ground truthing sites. Most permafrost studies place Whatì in the extensive discontinuous zone estimating that between 50 % - 90 % of the ground is underlain by permafrost. The underestimation and low accuracy show that ground truthing and accuracy assessments in this environment are critical.
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    Abstractive multi-document summarization - paraphrasing and compressing with neural networks
    (Lethbridge, Alta. : University of Lethbridge, Dept. of Mathematics and Computer Science, 2020) Egonmwan, Elozino Ofualagba; University of Lethbridge. Faculty of Arts and Science; Chali, Yllias
    This thesis presents studies in neural text summarization for single and multiple documents.The focus is on using sentence paraphrasing and compression for generating fluent summaries, especially in multi-document summarization where there is data paucity. A novel solution is to use transfer-learning from downstream tasks with an abundance of data. For this purpose, we pre-train three models for each of extractive summarization, paraphrase generation and sentence compression. We find that summarization datasets – CNN/DM and NEWSROOM – contain a number of noisy samples. Hence, we present a method for automatically filtering out this noise. We combine the representational power of the GRU-RNN and TRANSFORMER encoders in our paraphrase generation model. In training our sentence compression model, we investigate the impact of using different early-stopping criteria, such as embedding-based cosine similarity and F1. We utilize the pre-trained models (ours, GPT2 and T5) in different settings for single and multi-document summarization.
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    Abstractive text summarization based on neural fusion
    (Lethbridge, Alta. : University of Lethbridge, Dept. of Mathematics and Computer Science, 2023) Zhu, Wenzhao; University of Lethbride. Faculty of Arts and Science; Chali, Yllias
    Abstractive text summarization, in comparison to extractive text summarization, offers the potential to generate more accurate summaries. In our work, we present a stage-wise abstractive text summarization model that incorporates Elementary Discourse Unit (EDU) segmentation, EDU selection, and EDU fusion. We first segment the articles into a fine-grained form, EDUs, and build a Rhetorical Structure Theory (RST) tree for each article in order to represent the dependencies among EDUs; those EDUs are encoded in Graph Attention Networks (GATs); those with higher importance will be selected as candidates to be fused and the fusing stage is done by Bidirectional and Auto-Regressive Transformers (BART) model which merges the selected EDUs into summaries. A Greedy Method is leveraged to greedily select those EDUs whose combinations can maximize the ROUGE scores. Our model outperforms the baseline of BART (large) on the CNN/Daily Mail dataset, showing its effectiveness in abstractive text summarization.
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    Absurd realism in postmodern American fiction: Wallace, Pynchon, and Tomasula
    (Lethbridge, Alta. : University of Lethbridge, Dept. of English, c2013, 2013) Babalola, Titilola; Benzon, Kiki
    In this thesis, I examine absurd realism as a literary subgenre in postmodern American fiction. I define the concept of absurd realism, focusing on the features that characterize it as a postmodern subgenre. I also look at its relationship with other subgenres of literature such as realism, absurdism, magical realism, and satire. Through the analyses of three postmodern novels: David Foster Wallace’s The Pale King, Thomas Pynchon’s The Crying of Lot 49, and Steve Tomasula’s TOC: A New Media Novel, I illustrate how the features of absurd realism portray a postmodern world pervaded by boredom and chaos. I also consider how these texts convey the absurdity of human existence through the use of everyday characters, events, and setting. In summary, this thesis focuses on how the absurd occurrences and bizarre characters that exist within these books portray, in both literal and metaphoric senses, the complexity of the postmodern world.
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    Addiction, treatment, and evidence-based medicine
    (Lethbridge, Alta : University of Lethbridge, Dept. of Philosophy, 2016) Wilcox, Sean; University of Lethbridge. Faculty of Arts and Science; Brown, Bryson
    How addiction is conceived has important practical implications for how addicts are to be treated. This paper argues that we have a horrible concept of addiction and that has led to horrible treatment results. Examining this concept’s history will show that its main components (especially the brain disease view and the loss of control hypotheses) were invented or assumed by social reformers about 200 years ago, and that they do not map onto the physical world in a rich and systematic fashion. Science has been used to promote these assumptions instead of ever substantively establishing them. There are treatment methods that have been shown to be effective, but these are rarely employed in standard practice. Instead, addicts are provided with interventions that have been shown to be ineffective. Continuing to offer addicts treatment modalities that do not work when there are interventions with proven efficacy, is medical malpractice.
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    The adequacy of the retirement income system for retired middle-income Canadians
    (Lethbridge, Alta. : University of Lethbridge, Dept. of Political Science, 2022) Ebhomielen, Anderson Edo; University of Lethbridge. Faculty of Arts and Science; Hale, Geoffrey; Belanger, Yale D.
    Lower-income retired Canadians in income quintile one are well taken care of by the government’s income support system, while upper-income Canadians (income quintile five) typically have adequate income and investments in retirement. However, this thesis established that middle-income Canadians in income quintiles two, three, and four rely on a mix of retirement income sources to achieve sustainable pre-retirement living standards. Data analyses were used to determine the adequacy of the retirement income system. The thesis focused on selected periods of 2000, 2005, 2010, 2015, and 2018 and compared the performance of the RIS in Canada and across the selected provinces of British Columbia, Alberta, Ontario, Quebec, and Nova Scotia. This thesis established that the RIS is adequate for middle-income Canadians. Employment income during retirement has no significant relationship with the Gross Replacement Rate (GRR). The thesis confirmed that the RIS achieved its objectives through the various retirement income sources.
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    Adiabaticity of high strain rate compression testing using the Split Hopkinson Pressure Bar Apparatus
    (Lethbridge, Alta. : University of Lethbridge, Faculty of Arts and Science, 1997, 1997) Walton, Frank Stewart; University of Lethbridge. Faculty of Arts and Science; Kaminski, David
    In the development of explosively formed projectiles (EFPs), researchers are faced with the problem of testing prospective metals at high strain rates. So far it has been assumed that, relative to the cooling time, the deformation time is practically instantaneous indicating that the test is adiabatc: none of the heat generated within the metal is lost to conduction. In this paper we construct a model that subtracts out the effects of kinetic energy and uses specific heat as a function of temperature. In this way we can focus on the energy change in the specimen that can be attributed to temperature and determine just how adiabatic the high strain rate test is.