VictorJuiz/thesis huggingface dataset:
Impact of Corrosion Inhibitors on Lead Release and Biofilm Development in Simulated Partial Lead Service Lines

Partial lead service line replacements intended to decrease lead in drinking water but found to potentially increase lead release by galvanic corrosion. This study investigated the effects of corrosion inhibitors on lead release in simulate partial lead service lines. The performance of orthophosphate, zinc orthophosphate, and sodium silicate were compared under different water quality conditions (CSMR, conductivity, chlorination). Both orthophosphate and zinc orthophosphate immediately decreased lead release in all conditions, while sodium silicate seemed to slowly decrease lead release over time. Biofilm is a potential reservoir of lead in distribution systems, and the detachment of biofilm containing lead particles can cause health risk in drinking water. The effect of corrosion control on biofilm development was also examined under stagnant and flow-through conditions. Chlorination significantly decreased biofilm and was effective both under stagnant and flow-through conditions. The densities of ATP and lead in biofilm were typically consistent.

Keywords: biofilm
chloride-to-sulfate mass ratio
galvanic corrosion
orthophosphate
partial lead service line replacement
sodium silicate
Advisor: Andrews, Robert C
Payne, Sarah Jane O
The Making of the 'Problem Child': Egerton Ryerson and the Liberal Project of Ontario Public Education

What makes a problem child? In this thesis, I search for the conditions of possibility for the ‘problem child’, or a student who is constructed as someone who does not belong to the classroom. I focus on the works of Egerton Ryerson, Chief Superintendent at the genesis of Ontario public schooling, who proposed supposedly universal ‘common’ schools as well as residential schools, segregated schooling by race, and institutionalized schooling for disabled students and lower-class students. Rather than creating contradictions, Ryerson’s plans for common schools and separate schools are manifestations of his liberal philosophy, which supported a vision of public schooling that would produce a future civilized state. This conceptualization relies on the production of categories of uncivilized difference, which education can then manage and control. The figure of the ‘problem child’ shows that the very philosophy that promises universal education is dependent on the exclusion of many from that promise.

Keywords: Egerton Ryerson
Liberalism
Ontario
Problem Child
Public Education
Public School
Advisor: Titchkosky, Tanya
Imaging Amnestic Mild Cognitive Impairment: Neuroinflammation, Beta-amyloid and Glutathione

Amnestic mild cognitive impairment (aMCI) is defined as a transitional state between normal aging and Alzheimerâ s disease (AD). Neuroinflammation, amyloid accumulation and oxidative stress have been shown to contribute to the pathology of AD, however whether these processes occur in prodromal individuals is still not well understood. The main aim was to investigate, with the use of positron emission tomography, whether neuroinflammation is increased in aMCI patients and if it relates to amyloid burden in-vivo. Our exploratory aim was to measure glutathione, the brainâ s major antioxidant, in-vivo with the use of magnetic resonance spectroscopy. No significant differences in [18F]-FEPPA binding and glutathione levels were observed between healthy volunteers and aMCI patients. In contrast, aMCI patients were found to have significantly more amyloid in the cortical regions. Our findings suggest that amyloid pathology is an early event, whereas neuroinflammation and alterations in glutathione may occur only after conversion to AD.

Keywords: Amyloid
Glutathione
Magnetic resonance spectroscopy
Mild cognitive impairment
Neuroinflammation
Positron emission tomography
Advisor: Mizrahi, Romina
Isolation of Carbapenemase Producing Enterobacteriaceae in the Greater Toronto Area's Sewage Treatment Plants and Surface Waters, and their Comparison to Clinical CPE from Toronto

The presence and significance of Carbapenemase-producing Enterobacteriaceae (CPE) in Toronto's water system remains elusive. We sampled sewage from 5 sewage treatment plants and 7 surface water (SW) locations. Overall, 57/103 sewage specimens yielded 172 unique CPE and 2/7 SW locations yielded 8 CPE. Klebsiella oxytoca was the most common organism(31.9%) and blaKPC was the most common gene(88.4%) identified. blaKPC, blaOXA-48-like, and blaVIM genes were more frequently detected by raw sewage PCR method than filter sweep PCR, or culture method. In contrast, blaNDM genes were detected in approximately equal numbers of specimens by each method. Two Enterobacter cloacae blaVIM water isolates were clonally related to human isolates. K. oxytoca blaKPC clinical and sewage isolates were not clonally related; however, 3 sewage and 3 clinical isolates shared the same plasmid size and incompatibility group(IncFIIA). CPE are present in Torontoâ s sewage and SW, and some isolates are found in both water and humans.

Keywords: Antibiotic resistance
Carbapenemase-producing Enterobacteriaceae
CPE
Greater Toronto Area
Sewage Treatment Plant
Superbacteria
Advisor: McGeer, Allison
Post-anaesthesia Education for Parents of Pediatric Dental Patients having General Anaesthesia: Effect of the Presence of a Recovering Child on Recall and Compliance

Background: Post-anaesthesia education (P-AE) is a critical component of care typically provided to parents after their child’s dental treatment under general anaesthesia (GA) Objective: To assess parent’s recall and compliance of P-AE depending on whether the P-AE was delivered in the presence or absence of their child. Method: Parents of children (aged 2-9 years; ASA I-II; receiving dental treatment under GA) were randomly assigned to receive P-AE with their child either present (in recovery) or absent (during treatment). Compliance and recall of P-AE was assessed in a phone interview 1 day post-op. Results: The presence or absence of a recovering child during P-AE did not result in significant differences in parents’ recall and compliance. In both groups, recall of education material was low, whereas compliance was higher. Conclusion: Given the serious, albeit rare occurrence of complications following GA, optimizing the delivery of P-AE needs further investigation to improve retention of information by parents.

Keywords: anaesthesia education
Anesthesia
Compliance
Dentistry
Education
Recall
Advisor: Dempster, Laura
The Role of Internal Noise in Self-Motion Perception

In this study, vestibular-based motion perception was investigated. The vestibular system, located in the inner ear, is responsible for sensing translational and rotational motion. A previous study carried out at the University of Toronto found that motion discriminability degraded with increasing motion intensity. Namely, difference thresholds were observed to grow when the amplitude of stimuli increased, suggesting internal noise effects. The current work served as a follow-up to this study and developed a simulation framework to reproduce the results. Analysis of the experiment confirmed that trends in thresholds did not arise due to external motion base noise. Signal detection theory was used as a framework to model the discrimination task and a particle filter perception model was modified to permit the estimation of noise in the otolith, the organ responsible for detecting specific force. Given the limited dataset, simulations successfully reproduced the experimental findings while quantifying the contributions of the internal noise source.

Keywords: Flight Simulation
Motion Perception
Threshold
Vestibular
Advisor: Grant, Peter R
Goldfish Pyramidal and Stellate Neurons Respond Differently to Anoxia

With oxygen deprivation the mammalian brain undergoes excito-toxic cell death but this does not occur in the anoxia tolerant goldfish. Since GABA is the major inhibitory neurotransmitter in the brain, I investigated its potential role in preventing hyper-excitability in goldfish telencephalon neurons. Utilizing patch-clamp technique, the electrical activities of both excitatory (pyramidal) and inhibitory (stellate) neurons were recorded. With anoxia, membrane potential depolarized in both cell types. While pyramidal cells remained mostly quiescent, action-potential frequency of the stellate neurons increased. Further, the GABAA receptor reversal potential (EÂŹGABA) was depolarizing in both cell types. Inhibition of GABAA receptors reversed the anoxic response, while GABAB receptor inhibition did not induce a response. Co-antagonism of both GABAA/B receptors generated seizure-like neuronal activity. I conclude that GABA is vital for the anoxic survival of the goldfish and that the increased stellate neuron activity likely results in inhibition of pyramidal neuron activity with anoxia.

Keywords: Anoxia
EGABA
GABA
GABA receptors
Goldfish
Advisor: Buck, Leslie T
Nationalism in Crisis: The Reconstruction of South Korean Nationalism in Korean History Textbooks (Han'guksa)

South Korea has undergone considerable transitions between dictatorship and democracy under Korea's extraordinary status as a divided nation. The nature of this division developed an intense political contestation in South Korea between the political Left who espouse a critical view of top-down national history, and the Right who value the official view of South Korea's national history. Whether it is a national history or nationalist history, in terms of conceptions of national identity and nationalism in relation to Korean history, disagreement continues. The purpose of this thesis is not to support nor refute the veracity of either political position, which is divided between a sensationalized political Right and a caricaturized Left. The aim of this project is to evaluate a series of developments in Korean history textbooks that can be seen as a recent attempt to build new national identities.

Keywords: Han'guksa
Korean history textbook
Korean history textbook controversies
Korean nationalism
Kyohaksa
South Korea
Advisor: Schmid, Andre
Body Schema Modulation and Tool Embodiment in Real and Virtual Environments

Tool embodiment occurs when the neural representation of the body (i.e., body schema) incorporates the representation of a tool following interaction with the tool. The present thesis examined if tool embodiment can occur through different mediums of tool interactions. Participants completed a response time task (sensitive to tool embodiment) before and after interacting with one of three tools. In the physical tool interaction, participants held a real plastic rake to move a ball around a course. In two virtual tool interactions, an avatar holding a virtual rake was projected on to a screen and participants used a keyboard or a Wiiâ ˘ remote to move the virtual rake. Response time results indicate that prior to interaction, the rake was processed as separate from the body. However, through real and virtual tool experience, the rake was embodied such that it was incorporated into the body schema and processed as an extension of the hand.

Keywords: Body Schema
Motor Control
Neuropsychology
Tool Embodiment
Advisor: Welsh, Timothy N
Mental Disorder Profiles in Justice-involved Youth

As a population, justice-involved youth are characterized by high rates of comorbid mental disorders. However, past research has generally considered disorders singly. It is unclear whether disorders cluster together in a way that has implications for intervention and case management of justice-involved youth. To begin to explore this issue, cluster analysis was used to identify common diagnostic profiles in a sample of 195 youth who received court-ordered assessments. Six mental disorder clusters emerged, which were then examined in relation to youthsâ risk to reoffend, criminogenic needs, interventions received during probation, and recidivism. Two clusters were characterized by relatively higher reoffense rates: youth with disruptive behavior disorders alone, and youth with the profile of disruptive behavior disorders, learning disability, and ADHD. These clusters also significantly predicted odds of reoffense even after accounting for youthsâ static risk and criminogenic needs treatment. Implications for risk assessment and rehabilitation of justice-involved youth are discussed.

Keywords: Mental Disorder Profiles
Mental Health
Risk-Need-Responsivity
Youth Justice
Advisor: Peterson-Badali, Michele
The Role of Canadian Zoos and Aquaria in Species at Risk Conservation

Though many zoos have been participating in conservation activities for decades, academics have yet to conduct a thorough analysis of how zoos and aquaria are assisting in the recovery of species at risk. This thesis investigates the role of Canadian zoos and aquaria in conservation by using a combination of interviews with zoo staff members, observations of people at zoo exhibits, and multi-level species recovery document analysis. I argue that zoos in Canada are uniquely placed to make a substantial contribution to species at risk recovery in several main areas, including captive breeding and reintroductions, research, education, and recovery strategy development. However, financial limitations are holding these institutions back from growing their involvement in species at risk conservation, despite the pressing need for more non-governmental organizations, such as zoos, to take on a more active role in species recovery.

Keywords: Conservation
Species at Risk
Zoos
Advisor: Olive, Andrea
Neurostructural Correlates of Body Mass Index & Waist Circumference in Adolescents with Bipolar Disorder

Obesity among youth with bipolar disorder (BD) is associated with greater illness severity. In adult BD, obesity is associated with neurostructural differences. We examined this topic for the first time in youth. T1-weighted images of 40 BD and 48 psychiatrically healthy controls (HC) were processed using FreeSurfer to derive cortical region of interest (ROI) volumes/cortical thickness for frontal lobe (FL), prefrontal cortex (PFC), and orbitofrontal cortex (OFC), as well as subcortical ROI volumes for amygdala and hippocampus. Our results show that there was a significant BMI-by-group interaction effect on FL and OFC volumes. In the BD group only, BMI was significantly negatively associated with OFC volume, as well as FL, OFC, and PFC cortical thickness. Our results suggest that elevated BMI is associated with neurostructural changes in youth with BD but not in HC. Treatment studies examining the effect of optimizing weight on brain structure in BD are warranted.

Keywords: Bipolar Disorder
BMI
Body Mass Index
Brain Structure
Obesity
Advisor: Goldstein, Benjamin I
Identifying Predictors of Functional Outcome after Stroke: Impact of Post-stroke Depressive Symptoms, Obstructive Sleep Apnea and Cognitive Impairment on Long-term Body Function, Activity and Participation

Background: Stroke impacts multiple levels of function. Few studies have examined the long-term impact of common post-stroke comorbidities, or examined multiple functional domains. Methods: Baseline assessment of depression, apnea and cognition with 2-year follow-up assessment of functional outcome including: Body Function (MoCA), Activity (mRS) and Participation (RNLI). Results: Long-term activity limitation was predicted by greater age (OR = 0.95), activity limitations (OR = 0.38) and cognitive impairment (OR = 1.28) at baseline. Body function impairment was predicted by greater age (OR = 0.96), fewer education years (OR = 1.19) and cognitive impairment (OR = 1.63). Participation restriction was predicted by activity limitations (OR = 0.48) and cognitive impairment (OR = 1.26). Of those with good mRS outcome, 54.4% were cognitively impaired and 51.6% had participation restrictions. Conclusion: Baseline cognition predicts long-term deficits across functional domains. Assessment of post-stroke cognition and greater attention to multiple levels of functioning is warranted.

Advisor: Swartz, Richard H
Phatic Competence: How L2 Understand and Engage in Phatic Communion

Phatic communion, or “small talk,” has long been overlooked in literature on both pragmatics and language learning. This project examines L2 phatic competence by looking at how adult English language learners (ELLs) engage in phatic communion outside the classroom, and how they identify and interpret phatic interactions. Naturalistic data were collected from unstructured conversations in “conversation pubs.” The data were analyzed from an interactional standpoint, with a focus on performativity and a view to what strategies participants employ to engage in phatic communion, and were supplemented with semi-structured interviews and the researcher’s own background knowledge of the participants. Phatic communion came to be defined by the participants themselves, and is enacted in this study through a variety of speaker strategies and indexical cues. This project aims to provide valuable data regarding L2 phatic use and interpretation, with implications for researchers, language educators and professionals.

Keywords: ESL
Language learning
Phatic communion
Pragmatics
Advisor: Kerekes, Julie
Developing a Lead Compound for the Inhibition of Bacterial DNA Gyrase

The impacts of multi-drug resistant bacteria have an estimated global cost of $40 billion and provide precedence for the development of novel therapeutics. DNA gyrase is an essential DNA supercoiling enzyme in the bacterial DNA processing pathway. The present study focuses on using drug design approaches to develop a lead compound for the inhibition of DNA gyrase. In silico ligand docking simulations were conducted on an X-ray crystal structure of DNA gyrase subunit B and a library of 4,5-disubstituted thiophene derivatives. The highest-scoring compounds were tested as in vitro inhibitors of E.coli DNA gyrase, with compound 6 exhibiting an IC50 of 52.09µM. Analogues were subsequently synthesized using Suzuki-Miyaura cross-coupling chemistry and tested as DNA gyrase inhibitors. Although compound 43f did not demonstrate a statistical improvement in potency (IC50= 40.12±9.9µM), it induced zones of inhibition for susceptible and levofloxacin-resistant Staphylococcus aureus and MRSA in an Agar Diffusion Test.

Advisor: Weaver, Donald F
Economic Evaluation of Infant Feeding Modalities for Mothers in Canada Living with HIV

Aim: To determine if exclusive breastfeeding (EBF) or exclusive formula feeding (EFF) is more cost-effective when the mother is living with HIV and fully virally suppressed. This research was conducted in Canada where mothers living with HIV are currently advised to practice EFF to eliminate the risk of perinatal transmission. Methods: A micro-simulation model was developed to estimate lifetime costs and effectiveness of EBF and EFF, from the Ontario Ministry of Health perspective. Uncertainties around model parameters were evaluated using one-way and probabilistic sensitivity analyses. Results: In comparison to EFF, EBF was the dominant feeding modality (less costly and more effective) yielding cost-savings of $13,812.49 for each additional quality-adjusted life year. Conclusion: Despite the risk of HIV transmission, EBF was more cost-effective than EFF. These findings suggest that a review be undertaken of current infant feeding guidelines for mothers living with HIV in the context of high-income countries.

Keywords: Breastfeeding
Cost-Effectiveness Analysis
Formula Feeding
Health economics
HIV
Infant Feeding
Advisor: Loutfy, Mona R
Coyte, Peter C
Effect of Vitamin D Deficiency on Autophagy in the Intestine via MicroRNA Regulation

Rates of IBD have increased drastically over the past decade, greatest in children, asserting a role for the environment in disease pathogenesis. Emerging evidence has shown that vitamin D deficiency can affect the autophagy pathway and disrupt intestinal homeostasis, contributing to IBD. Epigenetic regulation through miRNAs may be a mechanism connecting vitamin D deficiency to dysregulated autophagy in IBD. Our study characterizes in the intestine the effect of vitamin D deficiency on autophagy via regulation by the miRNA, miR-142-3p. This research builds on data indicating miR-142-3p regulation of autophagy gene ATG16L1 and miR-142-3p overexpression in the intestine of IBD patients. Here, we demonstrate that vitamin D deficiency causes decreased ATG16L1 protein expression in the intestine. This poses a potential mechanism by which the environment interacts with genetics leading to IBD.

Keywords: Autophagy
Epigenetics
Inflammatory Bowel Disease
MicroRNA
Vitamin D
Advisor: Jones, Nicola L
Acidic Ferric Sulphate Leaching of Pyrrhotite Tailings at 55-80 째C and at Constant Redox Potential

The kinetics of nickel leaching and elemental sulphur formation from pyrrhotite tailings leached with ferric sulphate at 55-80 °C was investigated at constant oxidation-reduction potential (ORP). The tailings samples originated from Glencore’s Strathcona Mill in Sudbury, ON, Canada. Potassium permanganate was used to maintain a constant ORP. The shrinking core model (SCM) was used in conjunction with the particle size distribution (PSD) to determine the controlling reaction mechanism and quantify the leaching kinetics. In contrast to previous studies, accounting for the PSD helped identify that the rate-limiting step of the process was the rate of chemical reaction on the particle surface. A reaction order of 0.43 ± 0.08 with respect to ferric ion, and -0.18 ± 0.02 with respect to ferrous ion was found, along with an activation energy of 32.7 ± 0.2 kJ/mol. Additionally, elemental sulphur yield increased with increasing temperature.

Keywords: Hydrometallurgy
Nickel
Pyrrhotite
Tailings
Advisor: Papangelakis, Vladimiros G
Gaseous and Particulate Matter Emissions of a Supercharged Spark Ignited Hydrogen Fueled Internal Combustion Engine

A spark ignited hydrogen fueled engine was operated at three equivalence ratios (0.4, 0.5, and 0.6) with a supercharger. During steady-state road load conditions, the engine produced exceptionally low unburned hydrocarbon, carbon monoxide, carbon dioxide, and particulate matter emissions. The oxides of nitrogen (NOx) emissions of the supercharged engine were 31.4, 149.5, and 787.0 mg*NOx/km for the equivalence ratios 0.4, 0.5, and 0.6 respectively. Given that the current EPA regulations are 99.4 mg*NOx/km, this engine configuration represents a possible replacement option for gasoline fueled engines without the need for exhaust aftertreatment. During engine start-up, some of the supercharged tests exhibited particulate matter emission spikes. These particulate matter spikes do not seem to be related to equivalence ratio, coolant temperature, testing order, or start-up acceleration. Currently, there is no explanation why some of the tests produced particulate matter during engine start-up and others did not.

Keywords: Combustion
Engine
Hydrogen
NOx
Particulate Matter
Supercharged
Advisor: Wallace, James