VictorJuiz/thesis huggingface dataset:
Sex-related Differences in Healthcare Access and Utilization in Adult Patients with Inflammatory Arthritis in Ontario

This thesis compared healthcare access and utilization between male and female patients with inflammatory arthritis (IA) in Ontario. Using Ontario health administrative data, inception cohorts of adult patients with rheumatoid arthritis (RA), ankylosing spondylitis (AS) and psoriatic arthritis (PsA) diagnosed between 2010 and 2017 were assembled. Annual healthcare access and utilization patterns were assessed for 3 years before and after diagnosis, and compared between male and female patients using regression models. Before and after diagnosis, female patients were more likely to visit family physicians and rheumatologists, and undergo musculoskeletal imaging and laboratory tests across the cohorts. Opioids and NSAIDs were more likely to be dispensed to older female RA patients and, conventional disease modifying anti-rheumatic drugs to older female AS patients. In summary, female IA patients have higher musculoskeletal-related healthcare utilization than male patients, either due to biological differences in disease activity or sociocultural differences in healthcare seeking behaviour.

Keywords: ankylosing spondylitis
healthcare utilization
psoriatic arthritis
rheumatoid arthritis
sex and gender
sex differences
Advisor: Eder, Lihi LE
Approaching a Cultural Understanding of Suicide and Complex Death Among Older Indigenous Adults: Perspectives of Indigenous Elders

Indigenous people across Canada are disproportionately affected by suicide. Yet, little research has been conducted that examines how older Indigenous adults are impacted. Additionally, cultural factors of suicide are often overlooked. This research aimed to center the voices of Indigenous Elders to contribute to nuanced conceptualizations of the meaning of suicide within Indigenous populations to include key cultural dimensions and the experiences of older Indigenous peoples. Semi-structured qualitative interviews were held with six Indigenous Elders. Narrative analysis revealed three main themes and several subthemes related to meanings of death, complex death, and suicide, and three main themes with several subthemes related to ecological contexts of suicide. Results indicate a need to rethink conventional definitions of suicide to include a deeper understanding of complex death and relational and spiritual dimensions. The findings also indicated a need to address systemic racism, structural violence, and economic marginalization of Indigenous populations.

Keywords: Culture
Elders
Indigenous
Suicide
Advisor: Ansloos, Jeffrey
Synthesis and Characterization of MAA-Containing Polyol Latexes Tested in Model 2K-WPU Mixtures and Coatings

Waterborne two-component polyurethane (2K-WPU) films are safer, more environmentally friendly, and less hazardous than their solventborne counterparts. However, due to the complex interplay between polymer diffusion and colloidal forces, today’s researchers do not have a complete understanding of the mechanisms that underlie 2K-WPU behavior. To advance this knowledge, the Winnik group created a model 2K-WPU system consisting of methacrylic acid (MAA)-containing polyol latexes and a commercially available hmPIC, both of which were functionalized with fluorescent dyes. By studying these systems with dynamic light scattering (DLS), Fourier-transformed infrared spectroscopy (FTIR), and time-correlated single photon counting (TCSPC), several conclusions were made. It was found that MAA functionalization reduces aggregation in 2K-WPU dispersions, while also increasing the rate of hmPIC consumption. Most interestingly, increasing amounts of MAA increased the extent of hmPIC/polyol mixing in both dispersed and film phases, which may improve 2K-WPU physical properties.

Keywords: 2K-WPU
coatings
FRET
polyurethane
sustainability
thermoset
Advisor: Winnik, Mitchell
Predicting Shear Behaviour of Joints Using Multi-Sensor and Manual Core Logging Data and Supervised and Unsupervised Learning Methods

Joint surface characteristics significantly influence the shear behavior of discontinuity and the geomechanical design of a surface and underground excavation. Conventional core logging method for joint surface characterization is subjective and inconsistent. Sensor-based technologies can be adopted for surface characterization.This thesis compares manual and multi-sensor joint surface characterization to demonstrate the discrepancy between the manual and digital logging techniques. Joints detected over more than 500 meters of core samples were logged. A handheld 3D scanner, hardness test, and pXRF were performed on the joints to measure roughness, joint wall hardness, and a proxy for alteration mineralogy at discontinuity surface, respectively. Ja and Jr were assigned to the joints based on observations. Unsupervised learning techniques were used to classify the joints based on their surface characteristics. Samples from each class were selected for the direct shear test. Finally, unsupervised and supervised learning techniques were applied to predict joints' shear behaviour.

Keywords: Joint Alteration
Joint Roughness Coefficient
Multi-Sensor Core Logging
Residual Friction Angle
Shear Behaviour of Joints
Shear Strength
Advisor: Esmaeili, Kamran
Studying the Effects of Focused Ultrasound-triggered Drug Delivery and Deep Brain Stimulation on Post-traumatic Stress Disorder-type Behaviour

This thesis investigates the effects of neuromodulation therapies and sex differences in a rodent model of posttraumatic stress disorder (PTSD). Firstly, it sought to assess whether focused ultrasound-mediated delivery of pentobarbital using nanodroplets to the basolateral amygdala (BLA) would lead to therapeutic benefits on fear- and anxiety-like behaviour. Though we successfully delivered the drug and observed a marked decrease in BLA neuronal activity, no behavioural differences were found between animals receiving pentobarbital-loaded or empty nanodroplets. Next, we sought to establish a preclinical model of PTSD in female rats. Our results showed that females present extinction deficits and prolonged fear, but differences in the phases of the estrous cycle during extinction did not play a role on behavioural responses. Finally, we assessed the effects of deep brain stimulation (DBS), on the PTSD-type symptoms. Chronic DBS of the ventromedial prefrontal cortex (vmPFC) alleviated anxiety-type behaviour, but not the fear-type responses.

Keywords: Deep Brain Stimulation
Focused Ultrasound
Neuromodulation
preclinical models
PTSD
Advisor: Hamani, Clement CH
Simulation of Synthesizing Titanium Nanoparticles in a Radio-frequency Inductively Coupled Plasma

Following the rising demand for nanoparticles for plasmonic applications, Induction Plasma Synthesis is a promising technique for the synthesis of nanoparticles or nano-structured coating. A numerical study has been conducted on the evolution of Titanium particles in a radio-frequency (RF) inductively coupled plasma (ICP). A comprehensive model consisting of three sub-models is developed. A 2-dimensional axisymmetric computational model of a 40 MHz RF-ICP torch has been constructed to investigate the thermo-fluid field of the torch. The mathematical particle tracing model based on the Lagrangian tracking method incorporates the Stefan-Fuchs evaporation mechanism is built. And lastly, to understand the mechanism of nanoparticle formation such as nucleation and particle growth, a growth model under the scheme of the nodal method has been developed. Parametric studies for the influences of coil power, precursor particle size, and material feed rate are performed to find a way of controlling the operating conditions for desirable final particle size. The results of particle temperature, nucleation rate, particle mean diameter, and final size distribution are discussed.

Keywords: heat transfer
Nanomaterial
Plasma
Simulation
synthesis
Titanium
Advisor: Ruda, Harry
Reaction Intermediates Derived from Thiamin and Their Role in Benzoylformate Decarboxylase

The unexpected pyridinium catalysis of the enzymatic intermediate mandelylthiamin led to an investigation of a brominated analogue derived from a potent inhibitor of the enzyme benzoylformate decarboxylase that undergoes an elimination reaction to release bromide. The results suggest decarboxylation of para-(bromomethyl)mandelylthiamin is catalyzed by pyridine/pyridinium buffers through a proposed pre-association mechanism. This initially forms the protonated analogue that exists transiently before a rapid elimination process occurs. The findings indicate that the enzyme may not involve pre-association catalysis with the substrate but instead uses an alternate mechanism to separate CO2.Further investigations of the enzyme mechanism led to mutations of an active site serine residue. Replacement by the nucleophilic residue threonine altered the kinetic properties but provided similar rates of inactivation in the presence of a mechanism-based inhibitor, benzoylphosphonate. The results favor one inhibition mechanism in which serine and threonine attack free metaphosphate or carbon dioxide in solution to inactivate the enzyme. This mechanism has implications for a similar process when CO2 is present, with the nucleophilic residues acting as a trap forming hemicarbonate.

Advisor: Kluger, Ronald
Identifying Climate Refuges for Coral Reefs with a Life Histories Approach

Climate change is leading to widespread losses of corals, necessitating novel conservation strategies. One such strategy is the identification and protection of climate refugia where reefs escape the worst climate impacts. Recently, three types of coral climate refugia have been proposed: avoidance, resistance, and recovery. Here, we seek to address whether coral community composition and abundance of coral life histories can facilitate the classification of reefs into these refugia types. Using contemporary coral community composition from 122 surveyed reefs in four countries in the Western Indian Ocean from 2016-2019, we provide the first regional, empirical test of a proposed three-refugia reef framework. We found that the dominance of various life histories can classify reefs into these refugia types: avoidance refugia dominated by competitive corals; resistance refugia by stress-tolerant taxa; and recovery refugia by weedy life histories. Effectively protecting coral reefs requires an understanding of such diverse portfolios of climate refugia.

Advisor: Darling, Emily
Fortin, Marie-Josee
Libyan Higher Education in War times: Youth Participation in Higher Education in Libya

During the time of war in any country, higher education is one of the most affected sectors. However, despite the great challenges presented by warfare, there are people who become inspired to pursue their educational goals. This research explores the reasons that youth– both men and women – decide to participate in the Libya’s higher education system, despitethe impact of war that began in 2011. This research will contribute to the literature on what prompts motivation and resilience in time of war and conflict. The findings indicate that the students’ hopes, aspirations, plans, and dreams were factors behind youth motivation, meanwhile the factors associated with young people’s resilience came from community support, personal drive, and education as a form of protection. Theoretically, the study contributes to identifying and defining the specific individual attributes and broader social and community characteristics associated with persistence in higher education.

Keywords: civil war
higher education and youth participation
Libya
militias
youth motivation
youth resilience
Advisor: Buckner, Elizabeth
Modelling the Effects of β-arrestin-Mediated Signaling in Cortical D2R Expressing Neurons using CRISPR-Cas9

Dopamine dysregulation is implicated in psychiatric disorders such as Schizophrenia, Bipolar Disorder, and Major Depression. These conditions are managed by antipsychotics, which can exert their effects through G-protein-mediated or β-arrestin-mediated signaling pathways, which may each regulate different behavioral responses. While the principles of biased signaling provide an attractive strategy for developing novel therapeutics for psychiatric conditions, older methods for surveying the contributions of β-arrestin pathway to behavior are limited. Therefore, this study sought to use CRISPR-Cas9 to generate a model for exploring whether loss of β-arrestin in a regional and cell-type-specific manner could affect psychomotor, emotional, cognitive, and social behaviors.

Keywords: beta-arrestin
cortex
CRISPR-Cas9
D2R
dopamine
Advisor: Beaulieu, Martin
Vehicle Motion Prediction Using Locally Conditioned Trajectory Sets

Vehicle motion prediction aims to regress a continuous future trajectory from past motion data for all agents in the scene. However, not all future trajectories are viable for each agent. Vehicle trajectories are often limited by factors such as current vehicle dynamics, an agent’s location in the scene, and legal traffic maneuvers. We look to use this idea and frame the vehicle motion prediction problem as a classification problem across a set of trajectories that are ensured to be viable. While other methods typically only consider vehicle dynamics, we look to also explicitly factor in lane geometries and traffic rules as constraints in our trajectory set generation. Although we are unable to achieve similar performance to SOTA, we show that even with minimal training data, this approach allows for generalization to completely new scenes with no retraining and minimal performance loss.

Keywords: Autonomous Vehicles
Lattice Graph
Machine Learning
Motion Prediction
Self Driving Vehicles
Trajectory Set
Advisor: Schoellig, Angela
Microplastics Removal in a Dynamic Coagulation-Flocculation-Sedimentation System

Most studies examining microplastics (MPs) removal during bench-scale trials have applied sweep flocculation, such that the impact of other coagulation mechanisms remains largely unknown. Furthermore, the use of bench-scale batch systems (e.g., jar testing), wherein the hydrodynamics bear little resemblance to their full-scale counterparts, is ubiquitous in the literature. In this study, MPs removal during jar tests and bench-scale continuous-flow trials was compared. The production of large aluminum hydroxide floc consistent with sweep flocculation was the dominant factor driving MPs removal. Under combined coagulation and sweep flocculation conditions, total MPs removal was lower (11 – 82%) during continuous-flow trials, suggesting that extrapolation of jar test results may overpredict removal in full-scale systems. Strong correlations were observed between MP concentration and turbidity reduction, indicating that it may potentially serve as a surrogate. As well, correlations were observed when comparing both floc size and concentration to the removal of MPs.

Keywords: Coagulation
Flocculation
Microplastics
Advisor: Andrews, Robert
Almuhtaram, Husein
Design of Porous Polydimethylsiloxane for Non-fouling Filtration

Membrane fouling is a severe issue in pressure-driven filtration processes. Fouling influences filtration performance and limits the lifetimes of membranes. To manage the interactions between membrane materials and foulants, designing anti-fouling membranes has drawn much attention. Infused polydimethylsiloxane (iPDMS) is a composition of PDMS that exhibits non-adhesive, non-wetting, and non-fouling properties. We hypothesize that iPDMS can work in narrow spaces inside porous PDMS materials. In this study, methods for generating tunable pore size, porosity, and pore connectivity have been tested for PDMS materials, in particular using green, water-soluble polyvinyl alcohol (PVA) electrospun nanofibers as templates. Porous structures were characterized by scanning electron microscopy, optical microscopy, and flow tests. The kinetics of template dissolution was studied via spectrophotometry. The chemical properties of PVA nanofiber-templated PDMS were elucidated via Raman spectroscopy and contact angle measurements. Our PVA nanofiber-templated PDMS membranes could be a candidate for infusion for applications in non-fouling microfiltration.

Keywords: bottom-up
electrospinning
filtration
nanoporous
porous polydimethylsiloxane
templating
Advisor: Hatton, Benjamin B
A Phylogeographic Analysis of the North American Medicinal Leech, Macrobdella decora

The data regarding population structure and biogeographic affinities of leeches are scarce despite their important roles in many ecosystems. I begin to address this knowledge gap by performing a phylogeographic analysis of the North American medicinal leech, Macrobdella decora (Say, 1824). A total of 224 M. decora specimens were collected from 35 localities. Using four loci (COI, ND1, 18S and 28S), I constructed a phylogeny which showed a lack of geographic structure among the different populations of M. decora, with individuals collected at a single locality representing monophyletic groups only on six occasions. An AMOVA test did show a significant difference between the genetic variation within populations and between populations (COI: FST = 0.65412, P < 0.00001; ND1: FST = 0.69245, P < 0.00001), which was largely driven by the same six monophyletic groups in the phylogeny. Finally, a Mantel test also showed a weak, but significant correlation between geographic distance and genetic distance (COI: r = 0.209, P = 0.027; ND1: r = 0.1289, P = 0.030). The weak structure suggests that M. decora is panmictic throughout its range, which could be due to a lack of geographic barriers to gene flow or a high capacity for dispersal via their hosts.

Keywords: Hirudinea
Historical Demography
Phylogeography
Population Structure
Advisor: Kvist, Sebastian
Mobility and Joint Motion Control Considerations in the Evaluation of Physical Performance Testing

The purpose of this thesis was to assess the following among varsity athletes: 1) The relationship between deadlift and broad jump performance and joint motion control of the knee and back across a range of tasks of different demands, 2) The relationship between deadlift and broad jump performance and active mobility of the ankle and hip, and 3) The relationship between those who possess active mobility of the ankle and hip and control of the knee and back. Control of the knee and back were related to broad jump and large effect sizes were present between groups that demonstrated control when compared to deadlift. Ankle mobility was related to broad jump and a range of meaningful effect sizes were present in relation to ankle and hip mobility and deadlift. Ankle mobility was related to knee control (p<0.05).

Keywords: Active Mobility
Joint Motion Control
Performance Testing
Physical Capacity
Advisor: Frost, David M
Children’s Perceptions of Dental Experiences and Ways to Improve Them

Children’s Perceptions of Dental Experiences and Ways to Improve ThemMaster of Science, 2023 Melika Modabber Paediatric Dentistry (Faculty of Dentistry), Univeristy of Toronto AbstractA qualitative study was conducted to explore children’s perceptions of their dental experiences and the acceptability of the CARD™ (C-Comfort, A-Ask, R-Relax, D-Distract) system, as adapted for the dental setting. Semi-structured virtual interviews were conducted from a purposive sample receiving dental care at the Paediatric Dental Clinic in University of Toronto. Deductive data analysis was performed using a Person-Centered Care framework (PCC). Twelve children (7 males) aged 8-12 years participated. Four themes were identified: (1) establishing a therapeutic relationship, (2) shared power and responsibility, (3) getting to know the person, and (4) empowering the person. Children emphasized the importance of clinic staff characteristics and communication skills. They expressed a desire to have an active role in their care decisions and reflected on their need for pre-operative education and parental presence. Children also felt that the modified CARD™ system was an effective tool to facilitate self-advocacy and optimize their dental experience.

Advisor: Dempster, Laura
Taddio, Anna
Solving Short-term and Long-term Multi-resource Server Management Problems in the Cloud with Queueing and Combinatorial Models

In recent years, an increasing number of companies and individuals use cloud services in their daily life. As their workload increases, the cloud providers pay more attention on managing their server capacities to reduce their expenses. In this thesis, we study the short-term capacity planning problem in data centers, and introduce a hybrid framework based on queuing model and combinatorial model. The framework calculates a deterministic server set with the minimum operational cost to satisfy the stochastic workload in a cloud. We embed the short-term framework into another framework that solves the long-term server capacity planning problem with longer planning horizon. The long-term framework calculates the periodic server purchasing plan to satisfy the workload in months or years with the minimum server purchasing cost and operational cost.Our experimental results indicate that both frameworks may calculate a solution to satisfy the workload in a reasonable runtime. Moreover, the solution is closer to the optimal when the workload is more stable.

Keywords: Cloud
Control Theory
Multi-resource
Queueing Theory
Scheduling
Advisor: Beck, Christopher
Senderovich, Arik
Automatic imitation among individuals with Obsessive-Compulsive symptoms

Humans display a strong tendency and capacity to imitate their peers, and this imitation might underlie various aspects of social cognition. Individuals with obsessive-compulsive (OC) symptoms exhibit deficits social cognition, but little is known about the imitative patterns that might underlie these deficits. The current study examined whether individuals with OC symptoms exhibited atypical patterns of hypo-imitation, and whether the animacy of a model impacted these patterns. Participants from the general population were recruited to complete a questionnaire measuring OC (Obsessive-Compulsive Inventory Revised: OCI-R) and comorbid symptoms, followed by the completion of an automatic imitation task. Based on their OCI-R scores ( 21) participants were subdivided into age/gender matched Low (LOC: 17) and High (HOC: 17) symptom groups. Contrary to predictions, individuals with OC symptoms exhibited atypical patterns of hyper-imitation, and the animacy of the model exaggerated these patterns in the opposite direction, which might be implicative for imitative training.

Advisor: Welsh, Timothy N
Understanding Generative Adversarial Networks in the Context of Game Theory and Control Theory

Since their introduction in 2014, generative adversarial networks have shown great success in various applications like video synthesis and image generation. Unlike the traditional approaches of distribution learning, GANs view the learning problem as a two-player zero-sum game. In this thesis, we study the optimization of GANs from the perspectives of dynamical systems and game theory.This thesis proposes level k gradient play, a novel first-order that can predict each player’s next action. We evaluate our algorithm on a variety of games and empirically demonstrate that training GANs with our algorithm is much more efficient and effective than traditional methods.Another contribution of this thesis is that we proposed a simplified framework to analyze the solutions of GANs. To the best of our knowledge, we provide the first analytical justification for the observation that well-performing stationary points of GANs need not be local Nash equilibria.

Keywords: Control Theory
Game Theory
Advisor: Pavel, Lacra