VictorJuiz/thesis huggingface dataset:
Listening to Marginalized Women in Toronto: A Dialogue about Breast and Cervical Cancer Screening
Keywords: breast
cancer
cervical
homeless
mental health
qualitative

This study explored the perceptions of women living in homeless shelters and women with severe mental health challenges about the factors influencing their decision-making processes regarding breast and cervical cancer screening. Twenty-six qualitative interviews were conducted and analyzed using thematic analysis. The aim of this exploratory study was to focus on meanings and actions with a broader view to identify the interplay between participants' narratives and social structures, medical praxis and policy implications. Results provided insights on both positive and negative prior cancer screening experiences, the role of power and trust in women's decision-making, and areas for improvement in health care provider/patient interactions. Outcomes of this investigation contribute to the future development of appropriately designed intervention programs. Tailored and effective health promotion strategies leading to life-long cancer screening behaviours among marginalized women may improve clinical outcomes, decrease treatment costs and save lives.
In vivo NMR-based Metabolomics of Daphnia magna: Exploring the Potential and Limitations
Keywords: Daphnia Magna
In vivo
Metabolomics
Nuclear Magnetic Resonance

Daphnia magna (a keystone species) is routinely used in understanding the toxicity of environmental contaminants. Traditional ecotoxicity methods use endpoints such as mortality to understand the toxicity of contaminants. To fully understand the impact of a stressor, the underlying biochemical pathways that drive the physiological changes in an organism must be studied. Here in vivo Nuclear Magnetic Resonance (NMR) spectroscopy was developed to understand the metabolomic changes that occur in 13C-labelled Daphnia magna in response to stress. A flow-system which delivered oxygen to daphnia inside an NMR tube allowed for a total experiment time of 48 hours. A baseline metabolomic profile D. magna was established from 1H/13C one dimensional (1D) and two dimensional (2D) NMR. Changes in the lipids/TriAcylGlycerides (TAG) and carbohydrates of daphnids under different physical conditions (male/female and pregnant/non-pregnant) were identified demonstrating the viability of this approach for studying the biochemical response of D. magna to contaminant exposure.
Early Age Activation of SCMs as Influenced by Alkali Content of Cement
Keywords: Activation of SCM
High Alites
Low-Alkali Cements

A lot of research has been done on the activation of SCMs in order to guarantee maximum performance of concrete whether through durability or strength, especially at early age. The use of SCMs along with low-alkali cements might be suggested as an approach to ensure optimal concrete conditions against extreme deterioration mechanisms such as alkali aggregate reactions. The issue with that is it is thought that the SCMs maybe better activated by high alkali content cements. This project investigates other drivers for activation, mainly the content of alite. From the test results it is concluded that although high alkali cement content with average alite content samples had high strength, so did the lowest alkali cement with the highest alite content.
Critical Oxygen Tensions of Neuronal Anoxic Defence Mechanisms in the Western Painted Turtle
Keywords: Anoxia Tolerance
Critical Oxygen Tension
GABA
Ischemia
Spike Arrest
Stroke

The critical oxygen tension (Pcrit) is the oxygen partial pressure at which oxidative metabolism can no longer support the energetic (ATP) needs of the cell, at which point the cell must either decrease its energetic needs, or produce ATP anaerobically. The Western Painted Turtle (Chrysemys picta) is an anoxia-tolerant vertebrate species that undergoes spike arrest to conserve ATP, by activating GABAA receptors and inhibiting action potential generation. The 𝑃crit of spike arrest was unknown and considered to be very low but my measurement suggests a range between 25 and 35 torr. Three additional changes occurred during spike arrest: mitochondrial membrane potential depolarized, cytosolic [Ca2+] increased and the production of reactive oxygen species (ROS) decreased, all of which both activate spike arrest downstream and are indicative of decreased mitochondrial respiration. My findings thus suggest that mitochondria might act as bioenergetic oxygen sensors for spike arrest once oxygen tension reaches𝑃Pcrit.
Efficient Spray-coated Colloidal Quantum Dot Solar Cells
Keywords: Colloidal quantum dots
Manufacturing
Photovoltaics
Spray coating

Colloidal quantum dots (CQDs) offer the promise of low-cost, high-performance solar cells due to their ability to be synthesized and deposited from solution, which makes it possible for this material to be adapted to production-scale manufacturing protocols such as roll-to-roll (R2R) processing. Here we describe the design and implementation of a spray- coating process for the fabrication of CQD solar cells. We find that spray-coated films are morphologically superior to films that were fabricated using the conventional spin-coating method. Spray coating is found to be effective at removing an electronic trap caused by an organic impurity, enhancing the diffusion length of the CQD film and leading to an average power conversion efficiency (PCE) of 6.5%, which is higher than the average PCE of spin- coated cells (5.2%). We also show that the spray process can be adapted to R2R methodologies and can be used to fabricate efficient solar cells with unconventional form factors, such as surfaces with multiple dimensions of curvature.
Functional Analysis of the Architecture of the Oro-facial and Hyoid Musculature: A Comparative 3D Modelling Study
Keywords: Anatomy
Biomechanics
Computer Modelling
Craniofacial
Muscle Architecture
Skeletal Muscle

The functions of the oro-facial and hyoid muscles are poorly understood, despite their importance in mastication and communication. Muscle architecture is an important determinant of function, but the lack of an architectural database is impeding understanding of the individual and coordinated activities of these muscles. The purpose was to digitize, model and analyze the architecture of the oro-facial and hyoid muscles to compare their force-generating and excursion capabilities, as determined by the muscle architectural parameters, at the muscle group, whole muscle, and muscle partition levels. In total, 9600 fibre bundles were digitized and modelled in 46 muscles. The functional characteristics of each muscle and its component parts were determined from the architectural parameters, line(s) of action, and force indices. Correlation of the volumetric musculotendinous data with the functional characteristics of a muscle provides a comprehensive approach to assessing the implications of muscle geometry in normal and pathological states.
An Objective Method to Quantify the Location Criterion used to Classify Species at Risk in Canada
Keywords: Canadian Species at Risk
COSEWIC
Freshwater Fish Conservation
IUCN
Location Criterion
Risk Designation

Location is an indicator often used in the conservation assessments of species by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). The guidelines on the definition and calculation of location have received criticism for their ambiguity. To examine the application of location, I summarized the use of locations in COSEWIC assessment reports for 86 Canadian freshwater taxa. I propose an alternative method for calculating location using a standardized geographic buffer. Simulations to test the applicability of the buffer were conducted in ArcGIS using distribution data, scale of the primary threat, and minimum area for viable population for 20 imperiled freshwater fish species of southern Ontario. The shape of the buffer is dependent on the species habitat and the primary threat to the species. My proposed objective method of calculating location will contribute to more accurate conservation assessments of species, and subsequent development and implementation of conservation strategies.
Investigation of the Effects of Beam Scattering and Beam Wandering on Laser Beams Passing through the Off-gas Duct of an Electric Arc Furnace
Keywords: Beam Wandering
Electric Arc Furnace
Mie Scattering
Scattering Model
Sensor
Vertical Flow Reactor

The goal of this project is to determine the effects of scattering and beam wandering on light that passes through the off-gas of electric arc furnaces. The effects of light scattering off of fine metal oxide particles and beam wandering (steering) due to temperature gradient and turbulence in the medium are investigated. Using Matlab, a numerical model was developed based on Mie theory to calculate the light transmission when the optical properties of the medium and particles as well as their physical characteristics are known. The main property is the refractive index of the dust material. Other necessary parameters are the incident wavelength, particle size and concentration of the particles per cm3 of the gas. The model was validated with literature and experimental data. The model showed that as the ratio of wavelength to particle diameter increases, the loss due to scattering decreases. Turbulent eddies and temperature gradients in the air cause the laser beam to broaden and deflect. Using a big collection lens can minimize the signal fluctuation caused by the beam wandering. A better understanding of these phenomena helps in designing optical sensors for process control systems.
Digestibility of Selected Resistant Starches in Humans
Keywords: AOAC 2002.02
AOAC 991.43
blood glucose responses
Hi-maize® 260 Hylon® VII Amioca
ileostomy model
resistant starch

Resistant starches (RSs) are food ingredient sources of fiber. Their fiber content is measured in vitro, which may not accurately reflect in vivo digestibility. Carbohydrate content of commercial starches (Hi-Maize® 260 [HM], Hylon® VII [HY] and Amioca [AM]) was determined in vivo. Fiber values for HM, HY and AM were: 32.8 g, 11.5 g and 0 g in vitro, 12.5 g, 40.8 g and 6.2 g from blood glucose study (n=10) and 18.7 g, 21.6 g and 1.7 g from ileostomy study (n=3). 13.4% and 43.5% of RS in HM and HY was recovered in effluent. Total bacterial count (TBC) was 10^9 CFU/ g of effluent and positive correlation (r=0.4955) existed between TBC and carbohydrates by difference for HM and HY. The in vitro AOAC 991.43 method underestimates fiber content in HY and AM and overestimates fiber content in HM and does not accurately reflect fiber content of RS products.
The Micropolitical Acumen of Secondary School Principals in Ontario
Keywords: education
leadership
micropolitics
principal
strategic
teachers

This study explores the micropolitical acumen of Ontario secondary school principals in their work with teachers. Secondary schools can be unwieldy because of their size, fragmented structure, and balkanization of departments. Effective principals must understand the micropolitics of this environment, work strategically with teachers, and reflect on their strategic action. Five secondary school principals, considered by teachers to be politically effective, were interviewed from one school board. The data was analysed by constant comparison regarding principals' understanding, strategic actions, and reflection within a micropolitical environment. Principals' strategies were categorized as follows: setting direction; communicating strategically; building relationships; gathering information; managing conflict; team-building; using policy strategically; and persuading. Three findings follow: gathering information and relationship building are foundational to other micropolitical strategies; principals perceive morals and micropolitics as interconnected; and principals' differing opinions regarding the nature of conflict in their role may influence the strategies they use.
An Investigation into the Effect of DNA Structural Polymorphism and Single-stranded DNA Binding Proteins on Repair of Disease-associated Slipped-DNA Repeats
Keywords: Alternative RPA
DNA structure
Myotonic dystrophy
Replication protein A
single-stranded DNA
Slipped-DNA

Gene-specific repeat expansions are the cause of a growing list of neurological diseases, including myotonic dystrophy type 1 and Huntington's disease. The formation of slipped-DNA structures in the expanded repeat sequences is thought to drive repeat instability and pathogenesis by impairing normal DNA metabolic processes. Here I show that slipped-DNAs with nicks located within the repeat tract displayed increased structural heterogeneity relative to slipped-DNAs with nicks located in the flanking sequence. Nick-in-repeat slipped-DNAs were repaired better than nick-in-flank slipped-DNAs, likely due to increased amounts of single-stranded DNA at the nicked repeat ends allowing for better repair factor binding. Single-stranded DNA binding proteins RPA and aRPA seem to play an important part in tissue-specific instability as both complexes are overexpressed in the brains of HD patients. Neither RPA nor aRPA was required for slipped-DNA repair, although they both enhanced slipped-DNA repair efficiency.
Model of Electrophysiology and Metabolism of The Heart
Keywords: Cardiology
Metabolism
NADH

Electrical and metabolic activities of the heart are closely connected, however, the dynamics of this relationship remains unclear. In this thesis, the relationship between the electrophysiology and metabolism of the heart is studied. Using mouse heart in Langendorff set-up and an optical system to measure NADH and calcium concurrently in endocardium of the mouse heart, the effect of heart rate on metabolism is studied. Based on the experimental measurements, a mathematical model of metabolism and electrophysiology of the heart is constructed and used for exploring new drug therapeutic strategies.
Bio-inspired Optimal Locomotion Reconfigurability of Quadruped Rovers using Central Pattern Generators
Keywords: Central Pattern Generators
Gait Generation
Gait Optimization
Quadruped Locomotion

Legged rovers are often considered as viable solutions for traversing unknown terrain. This work addresses the optimal locomotion reconfigurability of quadruped rovers, which consists of obtaining optimal locomotion modes, and transitioning between them. A 2D sagittal plane rover model is considered based on a domestic cat. Using a Genetic Algorithm, the gait, pose and control variables that minimize torque or maximize speed are found separately. The optimization approach takes into account the elimination of leg impact, while considering the entire variable spectrum. The optimal solutions are consistent with other works on gait optimization, and are similar to gaits found in quadruped animals as well. An online model-free gait planning framework is also implemented, that is based on Central Pattern Generators is implemented. It is used to generate joint and control trajectories for any arbitrarily varying speed profile, and shown to regulate locomotion transition and speed modulation, both endogenously and continuously.
Molecular Phylogenetics of Nav1.4a and Kir2.5 in the Neotropical Electric Knifefish family Hypopomidae (Osteichthys: Gymnotiformes)
Keywords: Electric organ
Gymnotiform
Hypopomidae
Interspecific variation
Kir2.5
Nav1.4a

Electric fishes possess electric organs that they use to electrolocate and communicate. The rate and frequency of electrical discharges are affected by ion channels. In this study, I sequence two genes that likely play key roles in the generation of electric organ discharges (Nav1.4a and Kir2.5) and test their utility as phylogenetic markers in the family Hypopomidae. In addition, I concatenate these two genes with cyt b and RAG2 to assess species relationships within Hypopomidae using parsimony and Bayesian analyses. Both Nav1.4a and Kir2.5 exhibit sufficient interspecific variation to assess species relationships, and the four genes produce concordant phylogenetic patterns. Ion channel genes are therefore useful markers for electric fish phylogenetics.
The Impact of Ontario's Bariatric Network on Health Services Utilization following Bariatric Surgery
Keywords: Bariatrics
Ontario
Outsourcing
Program
Surgery

In 2009, the Ontario Bariatric Network (OBN) was created to address the increasing demand for out-of-country bariatric services. This study evaluated the impact of the OBN on postoperative hospital services use among Ontario residents who received bariatric surgery. A retrospective, before-and-after study was conducted. All Ontario residents who underwent funded first-time bariatric surgery were included. Hospital services use within one year following surgery was compared between the 3-year periods before (2007-2009) and after (2010-2012) the OBN. A total of 5,617 and 6,896 patients received bariatric surgery before and after the OBN, respectively. After adjustment, the OBN was associated with fewer postoperative hospital services (RR 0.83, 95%CI 0.78-0.89, P
Efficiency Enhancement Techniques in Integrated Tri-mode DC-DC Converters
Keywords: Buck-boost
DC-DC converters
Efficiency enhancement
SMPS
Tri-mode

This thesis presents a tri-mode dc-dc converter that can operate in buck, boost and buck-boost configuration. A power transmission gate is implemented in the converter as the high side driver of the H-bridge output stage. A one-step dead-time correction technique is also implemented based on a previous work of buck converter topology. This tri-mode converter is designed to use the lithium-ion battery as input voltage source (2.7 to 4.2V) and provide an output voltage from 1 to 5V with an output current of up to 0.5A. The switching frequency is fixed at 1.5MHz. This converter combines different efficiency enhancement techniques such as power transmission gate, one-step dead-time correction and segmented power devices on one chip which increases the complexity of integrated circuit implementation. A peak efficiency of 93% is observed in the boost mode. A further improvement of 3.3% in the peak efficiency is achieved with dead-time correction.
A Dual-engine Fetch/Compute Overlay Processor for FPGAs
Keywords: FPGA
HLS
OpenCL
Overlay
Processor
Scheduling

High-Level-Synthesis (HLS) tools translate a software description of an application into custom FPGA logic, increasing designer productivity vs. Hardware Description Language (HDL) design flows. Overlays seek to further improve productivity by allowing the designer to target a software-programmable substrate instead of the underlying FPGA, raising abstraction and reducing application compile times. We propose a highly configurable dual-engine, fetch/compute overlay processor which is designed to achieve high throughput per unit area on data-parallel and compute intensive floating-point applications. The fetch component is newly proposed as part of this work. For the compute component, we use an improved version of the TILT overlay processor originally developed by Ovtcharov and Tili. As part of our evaluation, we rigorously compare the performance, area and productivity enabled by our proposed architecture to that of Altera's OpenCL HLS tool.
The Synthesis and Reactivity of Highly Electrophilic Phosphonium Cations
Keywords: bis-fluorophosphonium cations
chiral bis-phosphonium
electrophilic phosphonium cations
Group XV Lewis acids
hydrogen activation
main group catalysis

Main group Lewis acids are used in a variety of Lewis acid-mediated transformations and as co-catalysts for polymerization reactions. In recent years, group XIII Lewis acids such as BF3, AlCl3, and B(C6F5)3 have been under active investigation for their catalytic applications. Extending this chemistry to group XV elements, our group recently showed that the phosphonium cation, [(C6F5)3PF][B(C6F5)4] displayed significant Lewis acidity. [(C6F5)3PF][B(C6F5)4] was shown to perform catalytic hydrodefluorination of fluoroalkanes; hydrosilylation of alkenes, ketones, imines and nitriles; and transfer hydrogenation of olefins. Similar reactivity was observed for [(SIMes)PFPh2][B(C6F5)4]2, which acquires its Lewis acidity from dicationic charge rather than perfluorinated substituents. Herein, we describe our efforts towards hydrogen activation by [(C6F5)3PF][B(C6F5)4], especially for hydrogenation of imines. Furthermore, the facile synthesis of a library of bis-phosphonium systems and their applications in Lewis acid-mediated catalysis are discussed. The synthesis of a chiral bis-phosphonium which may have applications in asymmetric catalysis is also described.
Exploring Tetracoordinate Silicon Lewis Acids for Frustrated Lewis Pair Chemistry
Keywords: Carbon Dioxide Activation
Frustrated Lewis Pairs
Inorganic Chemistry
Lewis Acid
Silicon Lewis Acids

Although hundreds of papers have been published on frustrated Lewis pair (FLP) chemistry since 2006, only a small number of them have examined the use of silicon as a Lewis acid. Herein, we detail our efforts in employing tetracoordinate silicon Lewis acids (SLAs) in FLP chemistry. The synthesis of SLAs in the forms R4-nSi(OSO2CF3)n (n= 1, 2), R3SiN(SO2CF3)2, and RSi(C6F5)3 is described as well as investigations into their reactivity with a variety of small molecules. Silyl triflates are shown to activate carbon dioxide when paired with a secondary amine base to yield silyl carbamates. Sequestration of CO2 by silyl triflates and triflimides with trialkylphosphines is also described, as well as investigations into CO2 reduction.
Occupational Stress in Animal Shelter Workers
Keywords: animal-shelter
compassion fatigue
human-animal bond
occupational stress
secondary traumatic stress

There is a dearth of research focusing broadly on occupational stressors experienced by animal shelter workers. The present study aimed to classify aspects of shelter work that employees report as stressful and determine whether they fit with current perspectives on generic occupational stress. The sample consisted of 22 female adults employed in a variety of positions at shelters in Canada and the United States. A semi-structured interview used prompts based on current occupational stress literature and allowed for exploration of unprompted topics of workplace stress. Qualitative analysis of the data revealed 17 stressor categories, six of which were identified as shelter specific stressor categories. Evidence of trauma was not observed in the data. This study supports the contention that stressors exist in shelter work beyond euthanasia and that current models of occupational stress may be insufficient for describing the experiences of animal shelter workers.
Characterization of Thin Film (K,Na)NbO3 for Piezoelectric MEMS Actuators with Applications to Auto-Focus Systems of Hand-Held Devices
Keywords: Actuator
Lead free
MEMS
Piezoelectric
Thin film

A thin film piezoelectric MEMS actuator is designed and simulated to be used as the actuation mechanism of an auto-focus system of a camera phone. The proposed actuator is capable of moving a 4mg micro-lens by 79μm under an applied voltage of 40V. A microfabrication recipe is developed in order to fabricate the actuator using MEMS technology. To reduce negative environmental impacts the lead-free piezoelectric material potassium sodium niobate (known as KNN) is selected due to its relatively high piezoelectric constants. Thin films of KNN are RF sputtered at room temperature and subsequently annealed at high temperature to achieve films with a proper crystal structure. In order to reduce fabrication costs, a highly doped silicon wafer is used as both the structural layer and the bottom electrode, which eliminates the need to deposit a metal film. The films are characterized in terms of crystal structure, stoichiometry, microstructure and electrical properties.