Digital Commons Network^™

Albert Forms, Quaternions, Schubert Varieties & Embeddability, Jasmin Omanovic

Electronic Thesis and Dissertation Repository

The origin of embedding problems can be understood as an effort to find some minimal datum which describes certain algebraic or geometric objects. In the algebraic theory of quadratic forms, Pfister forms are studied for a litany of powerful properties and representations which make them particularly interesting to study in terms of embeddability. A generalization of these properties is captured by the study of central simple algebras carrying involutions, where we may characterize the involution by the existence of particular elements in the algebra. Extending this idea even further, embeddings are just flags in the Grassmannian, meaning that their study …

Sodium-Glucose Cotransporter-2 Inhibitor Use And The Risk Of Acute Kidney Injury In Older Adults In Routine Clinical Practice: A Population-Based Cohort Study, Carina Iskander

Electronic Thesis and Dissertation Repository

Regulatory agencies warn about acute kidney injury (AKI) risk following sodium-glucose cotransporter-2 (SGLT2) inhibitor use. This population-based retrospective cohort study in Ontario, Canada quantified the 90-day AKI risk in older adults who were newly dispensed either SGLT2 inhibitors or dipeptidyl peptidase-4 (DPP4) inhibitors in an outpatient setting between 2015 and 2017. Risk ratios (RR) were obtained using modified Poisson regression and risk differences using binomial regression. Relative to new use of a DPP4 inhibitor, initiation of an SGLT2 inhibitor was associated with a lower 90-day risk of a hospital encounter with AKI: 216 events in 19,611 patients (1.10%) versus 388 …

Cluster-Based Chained Transfer Learning For Energy Forecasting With Big Data, Yifang Tian

Electronic Thesis and Dissertation Repository

Smart meter popularity has resulted in the ability to collect big energy data and has created opportunities for large-scale energy forecasting. Machine Learning (ML) techniques commonly used for forecasting, such as neural networks, involve computationally intensive training typically with data from a single building/group to predict future consumption for that same building/group. With hundreds of thousands of smart meters, it becomes impractical or even infeasible to individually train a model for each meter. Consequently, this paper proposes Cluster-Based Chained Transfer Learning (CBCTL), an approach for building neural network-based models for many meters by taking advantage of already trained models through …

Clinical Application Of 3d Ultrasound In Neonatal Intraventricular Hemorrhage, Priyanka Roy

Electronic Thesis and Dissertation Repository

Preterm neonates are at risk for intraventricular hemorrhage (IVH) and subsequent post-hemorrhagic hydrocephalus (PHH). A well-accepted interventional therapy for PHH is ventricular tap (VT). Permanent treatment, ventriculo peritoneal shunt surgery (VPS) is required in the case of some neonates under some conditions (weight, immunological status, CSF protein level) who receive multiple interventions. The objective of this study was to apply a 3D ultrasound system clinically to determine CSF volume within the ventricle, to guide the neurosurgeon regarding the amount of CSF should be removed during every intervention, which lateral ventricle is better to intervene and to predict the possibilities of …

Prufrock: A Monodrama For Baritone And Electronics, Daniel Gardner

Electronic Thesis and Dissertation Repository

Prufrock is a musical dramatization of T.S. Eliot’s, The love song of J. Alfred Prufrock for solo baritone and electronics; a full performance of the work should take approximately forty (40) minutes.

The work uses text from both Eliot’s original publication and a section removed from the text called Prufrock’s Pervigilium—first published in Christopher Ricks’s Inventions of the March Hare—and superimposes a narrative onto Eliot’s monologue of a man whose internal experience differs wildly from reality. As such Prufrock emphasizes the psychodramatic elements of the original text, reflecting them through the use of “auditory illusions” (particularly those described …

Spatial And Temporal Characteristics Of Temperature-Precipitation Covariability Across Canada In A Changing Climate, Harsimrenjit Singh

Electronic Thesis and Dissertation Repository

Changes in the regional characteristics of temperature and precipitation can intensify the occurrence and severity of extreme events such as rain-on-snow induced flooding, droughts and wildfires. Analyzing these climate variables in isolation without considering their interdependencies might result in severe underestimation of their combined effects. In this study, copula functions are used to describe the joint behaviour of temperature and precipitation across Canada over a historical period of 1910-present using observations and further till the end of the 21st century using three large ensembles of regional climate models. Moreover, given the lack of observation data over Canada, gridded datasets are …

X-Ray Absorption Spectroscopy, X-Ray Diffraction And Optical Luminescence Studies Of Phase Transition Of Titania Nanotubes, Lu Yao

Electronic Thesis and Dissertation Repository

The one-dimensional (1D) TiO₂ nanotubes (NTs) and their derivatives have been extensively studied due to their wide applications, such as photocatalysts, solar cell, paints and so on. Since TiO₂ has a wide band gap (~3.0 eV), its photo-absorption as the photocatalyst only occurs in the UV region that wastes mostly solar energy. Therefore, the solution to higher photocatalytic efficiency has been sought for some time. This thesis presents a study of the size-dependent phase transitions of TiO₂ NTs using synchrotron-based X-ray techniques. The chemical environment including local symmetry and the luminescence origin of the TiO₂ NTs …

The Role Of Adult Hippocampal Neurogenesis In Depression-Relevant Reward-Related Behaviours, Katrina Zmavc

Electronic Thesis and Dissertation Repository

The variability in the symptomatology of depressive disorders and antidepressant treatment response has led to an increased interest in the molecular, cellular, and circuit mechanisms of many aspects of affect. Evidence suggests a reduction in adult hippocampal neurogenesis (AHN) is associated with an increase in depression-like behaviour, though much of this evidence has been from studies using aversive tests (e.g., forced swim test). Here, I used touchscreen operant chambers, which allow for non-aversive and translational testing, to test the hypothesis that AHN plays a contributing role in emotion regulation. A panel of three touchscreen tests were chosen to assess different …

Reliability And Validity Of Two Performance-Based Outcome Measures In Rehabilitation Following Total Knee Arthroplasty, Jennifer L. Van Bussel

Electronic Thesis and Dissertation Repository

Objectives: Performance-based outcome measures (PBOM) are suggested to evaluate change in function during rehabilitation after total knee arthroplasty (TKA). The purpose of this study was to evaluate the measurement properties of the 30-Second Chair Stand Test (30CST) and 10-Metre Walk Test (10MWT) in patients following TKA.

Methods: Eighty-three patients completed two PBOM on three occasions following surgery. Patients also completed the Western Ontario and McMaster Universities Osteoarthritis Index and Global Rating of Change (GRC).

Results: Intraclass correlation coefficients ranged from 0.82 to 0.96. The standard errors of measurement at 6 and 12 weeks postop, respectively, were: 30CST ±0.67 and ±0.79, …

Integrated Science 3002a: Proposal For Plumbing Initiative For Water Conservation In London, Rebecca Oeyangen, Jennifer Evans, Ali Coyle, John Chepesiuk, Nadia Aiaseh, Trystan Lee

Community Engaged Learning Final Projects

No abstract provided.

No Space To Sing: A Narrative Inquiry Into The Experiences Of Classical Singers With Primary Muscle Tension Dysphonia, Elizabeth Lepock

Electronic Thesis and Dissertation Repository

This study was designed as a qualitative narrative inquiry study into the experiences of classical singers with Primary Muscle Tension Dysphonia (PMTD). PMTD is defined as Muscle Tension Dysphonia (MTD) without organic or neurological factors. In the population of professional voice users, PMTD is typically associated with occupational/behavioural causes.

A review of the literature shows that occupational disorders are associated with stigma in the classical music community, that research on PMTD in the demographic of singers is sparse and often broadly defined, and that PMTD is not well-represented in the vocal pedagogy literature. Additionally, PMTD may present differently in classical …

Exploring Cognitive Maps Through Sketching, Melissa M. Nantais

Electronic Thesis and Dissertation Repository

Abstract

Periodic testing has been found to improve the accuracy of participants’ cognitive maps when an onscreen map is provided, however, it is unclear whether the same results would occur without the onscreen map. The current study investigated whether drawing a map periodically while exploring the virtual environment Silcton would improve cognitive map accuracy. Participants explored Silcton and were stopped every 4 minutes to either sketch a map of Silcton, identify items seen in Silcton, or colour an unrelated picture, and a baseline group was not stopped. All groups drew a final sketch map and completed a direction estimation task. …

Characterization And Computational Modelling For The Garnet Oxide Solid State Electrolyte Ta-Llzo, Colin A. Versnick

Electronic Thesis and Dissertation Repository

The all-solid-state-battery (ASSB) serves as a promising candidate for next generation lithium ion batteries for significant improvements in battery safety, capacity, and longevity. Of the material candidates researched to replace the conventionally used liquid electrolyte, the garnet oxide Ta-LLZO (Li_6.4La₃Zr_1.4Ta_0.6O₁₂) has received much attention thanks to its high chemical and electrochemical stability, and ionic conductivity which rivals that of liquid electrolytes. While much investigation has taken place regarding the electrochemical performance of Ta-LLZO, much less is known about the micromechanics, including microstructural characterization, stress and strain development, and material failure …

Investigating The Effects Of Tissue-Specific Extracellular Matrix On The Adipogenic And Osteogenic Differentiation Of Human Adipose-Derived Stromal Cells Within Composite Hydrogel Scaffolds, Arthi Shridhar, Brian G. Amsden, Elizabeth R. Gillies, Lauren E. Flynn

Bone and Joint Institute

© Copyright © 2019 Shridhar, Amsden, Gillies and Flynn. While it has been postulated that tissue-specific bioscaffolds derived from the extracellular matrix (ECM) can direct stem cell differentiation, systematic comparisons of multiple ECM sources are needed to more fully assess the benefits of incorporating tissue-specific ECM in stem cell culture and delivery platforms. To probe the effects of ECM sourced from decellularized adipose tissue (DAT) or decellularized trabecular bone (DTB) on the adipogenic and osteogenic differentiation of human adipose-derived stem/stromal cells (ASCs), a novel detergent-free decellularization protocol was developed for bovine trabecular bone that complemented our established detergent-free decellularization protocol …

High Strain Dynamic Test On Helical Piles: Analytical And Numerical Investigations, Mohammed Fahad Alwalan

Electronic Thesis and Dissertation Repository

Helical piles are currently considered a preferred foundation option in a wide range of engineering projects to provide high compressive and uplift resistance to static and dynamic loads. In view of the large capacity of large diameter helical piles, there is a need to determine their capacity using accurate and economically feasible testing techniques. The capacity of piles is usually determined by conducting a Static Load Test (SLT). However, the SLT can be costly and time consuming, especially for large capacity piles. The High Strain Dynamic Load Test (HSDT) evaluates the pile capacity using dynamic measurements generated through subjecting the …

Teaching Video Neuroimages: Atypical Childhood Epilepsy With Centrotemporal Spikes: Seizures Often Discussed, Rarely Seen, Egidio Spinelli, Khrystyna Moskalyk, Sunita N. Misra

Paediatrics Publications

A 7-year-old right-handed boy with poorly controlled epilepsy presented to the epilepsy monitoring unit for further clarification of his diagnosis. Seizure onset was at 3 years with focal motor seizures of left face and arm followed by confusion and aphasia. Prominent behavioral and school difficulties were also reported. Valproic acid monotherapy (23 mg/kg/d) was weaned by day 2 and a habitual event captured on day 5 (figure, video 1). Brain MRI and an epilepsy gene panel (including GRIN2A) were nonrevealing. The diagnosis was therefore consistent with atypical childhood epilepsy with centrotemporal spikes. This differs from benign rolandic epilepsy because of …

Perceptions Of Institutional Teaching Culture By Tenured, Tenure-Track, And Sessional Faculty, Debra Dawson, Ken Meadows, Erika Kustra, Kathryn Hanson

Centre for Teaching and Learning Publications

The Institutional Teaching Culture Perception Survey (ITCPS) was used to investigate beliefs of tenured, tenure-track, and sessional faculty members (N=576) about the teaching culture within three large research-intensive universities in Canada. As predicted, we found significant differences between these three groups of faculty members’ perceptions of their institutions’ teaching cultures. Sessional faculty perceived that their universities rewarded effective teaching less than their tenured or tenure-track colleagues. Tenured faculty were less likely than the tenure-track and sessional faculty to believe it was important to encourage, recognize, or assess effective teaching. These results have important implications for the quality of teaching and, …

The Simultaneous Book: Women's Writing In Contemporary Art, Maryse Lariviere

Electronic Thesis and Dissertation Repository

Novels written by women authors who don’t adhere to the classification “visual artist” are nonetheless gaining momentum in today's contemporary art world. Yet works by authors such as Chris Kraus or Catherine Millet are often not recognized as artist’s novels because their authors are not or/and do not consider themselves to be visual artists. I contend that we can usefully situate their work within the genre of the artist’s novel by addressing how they invent artistic postures and artistic alter-egos within the autofictional worlds of their texts. My dissertation The Simultaneous Book proposes to open up the definition of the …

Voice Analysis With Iphones: A Low Cost Experimental Solution, Benjamin Van Der Woerd

Electronic Thesis and Dissertation Repository

Background:

Acoustic voice analysis requires a resource intensive setup, including a soundproof booth. This project evaluates smartphone microphone and recording environment impacts on voice sample collection for acoustic voice analysis. A proprietary analysis algorithm is presented for validation.

Methods:

Microphone and recording environment were evaluated using previously collected voice samples presented in four conditions to test two microphones and two recording environments. Prospective samples were used to test the proprietary algorithm, whereby samples were analyzed using this and Praat.

Results:

Microphone and recording environment had small, clinically unimportant impacts on most measurements. The proprietary algorithm reliably analyzed sustained vowels, with …

Examining The Self-Schema Within A Cognitive Vulnerability-Stress Framework Of Mania, Nadia Maiolino

Electronic Thesis and Dissertation Repository

This dissertation aimed to inform a cognitive vulnerability-stress theory of mania, which addresses both the content and structure of the self-schema, along with the conditions under which these self-relevant cognitions are activated. Extant research on mania has primarily considered self-schema content, or an individual’s actual beliefs (e.g., “I am incompetent”). Although these investigations have successfully identified maladaptive self-beliefs associated with bipolar disorder, this research has been prone to inconsistencies and limited in distinguishing between mania and related forms of psychopathology (e.g., unipolar depression). Furthermore, very little research on mania has considered the organization of self-schema beliefs, referred to here as …

Temporalities Of Revolution: On The Representation Of History And Collective Action, Nicholas D. Tostowaryk

Electronic Thesis and Dissertation Repository

This thesis opens with a discussion of Rosa Luxemburg’s notion of “spontaneity,” which departs from a consideration of Luxemburg’s scientific socialism, the inevitability of capitalist collapse, and her assertion of socialism as the objective response to the contradictions of capitalism. For Luxemburg, then, spontaneity refers to the way in which proletarian consciousness forms in response to these conditions. The second chapter argues that Luxemburg’s notion of spontaneity represents what Walter Benjamin would call an historical articulation of the past, which is an articulation of the present and its struggles in terms of their historicity. I develop this argument through a …

Is Sabr Cost-Effective In Oligometastatic Cancer? An Economic Analysis Of Sabr-Comet Randomized Trial, Yujie Chen

Electronic Thesis and Dissertation Repository

The phase II randomized study SABR-COMET demonstrated that in cancer patients with 1-5 oligometastatic lesions, stereotactic ablative radiotherapy (SABR) was associated with an improvement in both progression-free survival and overall survival compared to standard of care (SoC). SABR, however, is associated with higher costs and treatment-related toxicity. The objective of this study was to assess the cost-effectiveness of SABR versus SoC in patients with oligometastatic disease.

A time-dependent Markov model with five health states was constructed from the Canadian health care system perspective. Utility values and transition probabilities were derived from the SABR-COMET trial. Costs were obtained from the published …

Application Of Bayesian Networks To Integrity Management Of Energy Pipelines, Wei Xiang

Electronic Thesis and Dissertation Repository

Metal-loss corrosion and third-party damage (TPD) are the leading threats to the integrity of buried oil and natural gas pipelines. This thesis employs Bayesian networks (BNs) and non-parametric Bayesian networks (NPBNs) to deal with four issues with regard to the reliability-based management program of corrosion and TPD. The first study integrates the quantification of measurement errors of the ILI tools, corrosion growth modeling and reliability analysis in a single dynamic Bayesian network (DBN) model, and employs the parameter learning technique to learn the parameters of the DBN model from the ILI-reported and filed-measured corrosion depths. The second study develops the …

Exploring Stretto: An Investigation Into The Use Of Stretto In J. S. Bach's Well-Tempered Clavier, Kathryn Mcdonald

Electronic Thesis and Dissertation Repository

Stretto—the technique of using a fugue subject in counterpoint with itself, beginning at different time points—occurs prevalently in fugues by J. S. Bach and other baroque composers. This study investigates the formal function of stretto using a corpus analysis of Bach’s use of stretto in the forty-eight fugues of the Well-Tempered Clavier. It documents details regarding each instance of stretto within the corpus and explores connections between these data using graphs and statistical tests, generally as well as in investigation of three specific hypotheses. The conclusion, density, and quantity hypotheses predict that there will be more stretto passages, time-intervals between …

Forward And Up: An Exploration Of Implementations Of The Alexander Technique In Post-Secondary Music Institutions, Mei Lee

Electronic Thesis and Dissertation Repository

Music performance is a psychophysical affair. Like athletes, musicians need to be physically, mentally, and emotionally fit in order to meet the demands and challenges of training and performing. For over half a century, post-secondary music institutions have been utilizing the Alexander Technique to address young musicians’ psychophysical coordination and playing-related challenges. This unique mind-body method teaches individuals how to move efficiently and carry out activities with freedom and ease by recognizing and changing counterproductive habits. It has noted beneficial effects on posture and coordination, pain relief, and stress management, and its relevance to music performance studies is endorsed by …

Quantification Of Surface Roughness Of Lava Flows On Mars, Carolina Rodriguez Sanchez-Vahamonde

Electronic Thesis and Dissertation Repository

Volcanism has played a significant role throughout Mars’ geologic history. Extensive lava flows are widely spread across Mars’ equatorial region, shaping the surface in a very distinct way. In radar images (at the decimeter scale), these flows are bright, which is a typical characteristic of extremely rough, blocky lavas flows seen on Earth. Although the source of the extreme roughness of Martian lava flows is unknown, their surface roughness parameters can be constrained to 1) gain information about Mars’ interior processes, 2) find appropriate analogues on other planetary bodies, and 3) ideally infer the emplacement style of such lavas. Here, …

Evaluating The Utility Of Protein Biomarker, S100a7, And Diagnostic Test, Straticyte, In Predicting The Progression Of Oral Dysplasia, Lachlan Mclean

Electronic Thesis and Dissertation Repository

Five-year survival of oral cancer has remained relatively unchanged despite advancements in treatment, mostly because diagnosis is often made at an advanced stage of disease. The progression of dysplasia to oral cancer often follows a stepwise progression. Histopathology is considered the ‘gold standard’ for diagnosing dysplasia and lesions at a high risk of progression to oral cancer, but lends itself to subjectivity. The protein biomarker, S100A7, in oral dysplasia and squamous cell carcinoma has shown some predictive value for the transformation of dysplasia to cancer. Straticyte, a diagnostic test utilizing S100A7 to predict the probability of progression of oral dysplasia …

Biomechanics Analysis Of Anterior Cortical Perforation In Antegrade Femoral Nailing, Michael Ching

Electronic Thesis and Dissertation Repository

Hip and femur fractures are a common problem in an aging population. The number of hip and femur fractures are on the rise in Canada. Cephalomedullary fixation is a common method of treating hip and femur fractures, with a known complication of anterior cortical perforation of the distal femur. The literature describes risk factors, such as the influence of the start point at the greater trochanter, but there is no consensus on management. Some cases are treated with restricted weightbearing and other cases with revision surgery. Restricted weightbearing increases perioperative complications including mortality and decreases functional outcomes.

We analyze the …

Electrochemical Investigation Into The External Failure Modes Of Oil And Gas Pipelines, Maxwell Goldman

Electronic Thesis and Dissertation Repository

Carbon steel is the material of choice for transmission pipelines for the oil and gas industry across the globe due to its mechanical properties, and low cost. Carbon steel is only resistffxidant, and the types of anions present in the exposure environment. Transmission pipelines are coated with non-conductive polymeric coatings and can be protected by cathodic protection in order to mitigate exterior corrosion. The primary goals of this thesis were to determine the role of anions, cathodic charging with hydrogen, and steel microstructure on different failure modes of carbon steel.

The corrosion mechanism of carbon steel in the presence of …

The Secretory Pathway Calcium Atpase 2c Promotes Increased Cytosolic Calcium Levels, Melissa Fenech

Electronic Thesis and Dissertation Repository

Pancreatic acinar cell exocytosis requires precise calcium (Ca²⁺) signals. When cytosolic Ca²⁺ levels remain high, cellular functions are disrupted, which is associated with initiation of pancreatitis. Ca²⁺ signals are achieved through regulating endoplasmic reticulum (ER) stores, Ca²⁺ATPases, and store-operated Ca²⁺ entry (SOCE). However, how these pathways interact to create precise signals is not well understood. In a pancreatic model of dysregulated Ca²⁺ homeostasis, secretory pathway Ca²⁺ATPase 2 (SPCA2) expression is significantly decreased. In the pancreas, only a C-terminally truncated form of SPCA2 (termed SPAC2C) exists. Recent studies indicate a role …