VictorJuiz/thesis huggingface dataset:
A Pilot Study of the Inflammatory Response in Oral Squamous Cell Carcinoma by Saliva Analysis

Oral squamous cell carcinoma (OSCC) often shows a pronounced inflammatory infiltrate. There is accumulating evidence that this inflammatory infiltrate plays an active role in tumor development and progression. We developed a protocol for collection and analysis of saliva and used it to characterize inflammatory cell and cytokine profile in the saliva of patients with OSCC. 37 patients with OSCC, 24 healthy patients, and 8 patients with periodontitis provided a saliva sample. Supernatants were analyzed using Luminex-based 30-Plex inflammatory panel. Cell pellets were fixed and analyzed using multichannel flow cytometry. The fluorescent markers included CD45, CD66b, CD3, CD4, CD8, CD25, CD56, CD68, CD138, Siglec8, PD1 and PDL1. OSCC group showed distinctive pattern of inflammation, with significantly higher neutrophil-to-lymphocyte ratio (NLR), CD4/CD8 ratio and IL1b, IL6 and TNFa concentration levels. Late stage disease was associated with higher NLR and CD4/CD8 ratio with increased IL1b and IL6.

Keywords: Biomarker
Cytokines
Flow cytometry
Inflammation
Oral cancer
Saliva
Advisor: Magalhaes, Marco
A Full-vectorial Theory of Third-order Nonlinear Optical Effects in Aluminum Gallium Arsenide Waveguides

A full-vectorial theory of third-order nonlinear effects is used to derive expressions for the nonlinear coefficients (NLCs) of waveguide modes in high-confinement Aluminum Gallium Arsenide (AlGaAs) waveguides. The dependence of the NLCs on the cross-section and orientation of AlGaAs-on-insulator (AlGaAsOI) waveguides is investigated via simulation. The results of the full-vectorial theory are compared to those of various scalar theories used in previous studies of AlGaAs waveguides. It is found that the scalar theories tend to underestimate the NLCs for high-confinement AlGaAsOI waveguides. Two of the three investigated scalar theories do not accurately predict the waveguide geometries that optimize the NLCs. Examples of applications of the full-vectorial theory to wavelength conversion are demonstrated for AlGaAsOI and plasmonic slot waveguides.

Keywords: Integrated
Nonlinear
Optics
Advisor: Aitchison, J. Stewart
Fire Containment Probability in Conifer Fuel Types in Ontario

I undertook a study to identify if a relationship between forest stand age and fire containment probability, identified previously in Alberta, existed in Ontario. I developed a Time Since Fire (TSF) for Ontario, estimating the total years that had passed since a large fire occurred in an area to the time a new fire occurred in the perimeter of the historic burn. I studied fire containment probability in C-2 (boreal spruce) stands in Ontario in relation to the TSF. I built a simulation model to assess the viability of aggregating conifer fuels in Ontario. I built an aggregate conifer fuel type dataset for Ontario to test for relationships with fire containment probability and TSF. I identified a relationship between fire containment probability and TSF in Ontario: increasing TSF was found to negatively impact fire containment probability for fires occurring in fuels with a conifer component.

Keywords: Fire Containment
Forestry
Wildfire
Advisor: Martell, David L
Machine-learning-accelerated Materials Discovery for Perovskites

Reaching the full potential of optoelectronic materials is often hindered by the years of necessary trial-and-error. Perovskites are an example of materials having exceptional optoelectronic properties, but require improvement with respect to stability and toxicity as they approach commercialization. Exploring new types of perovskites is key to achieving these goals. In this thesis I develop an accelerated materials discovery pipeline aimed at discovering new perovskite materials. This pipeline incorporates image recognition that detects crystals via convolutional neural networks with 95% accuracy and uses parameter exploration to predict an optimal material with experimental data. With this framework, I discovered a new type of perovskite single crystal, (3-PLA)2PbCl4, that employs a new ligand, 3-PLA, offering avenues to higher efficiency and more stable devices. This work develops a framework for discovering and optimizing materials in a wide chemical space and provides the groundwork for identifying new materials that lie beyond known chemical spaces.

Keywords: Machine learning
Materials discovery
Perovskites
Robotic crystallization
Single crystals
Advisor: Sargent, Edward H
A Parametric Study of Jet Fuel Thermal Stability

Thermal stability and degradation of a commercial jet fuel were studied using an experimental rig developed recently. The apparatus consists of a fuel pre-heating section to simulate the usage of fuel as a coolant on aircraft, and a test section to simulate operating conditions found in aircraft injector fuel nozzles. Two independent diagnostic techniques, pressure drop measurements and carbon burn-off, were applied to assess carbon deposition produced within a test section. Parametric studies were performed to investigate the effect of test section inner diameter, test section material, and test section inlet temperature gradient on carbon deposition within the test section. It was determined that as the inner diameter of a test section increased, carbon deposition generally decreased. The axial location of maximum surface deposition moved downstream in a narrower test section. It was also found that solid carbon deposition decreased by increasing the test section inlet temperature gradient.

Keywords: Carbon Deposition
Coking
Jet Fuel
Thermal Stability
Advisor: Gülder, Ömer L.
Bus Bridging Decision-Support Toolkit: Optimization Framework and Policy Analysis

Bus Bridging is the strategy most commonly applied in responding to rail service interruptions in North America and Europe. In determining the required number of buses and source routes, most transit agencies rely on ad-hoc approaches based on operational experience and constraints, which can lead to extensive delays and queue build-ups at affected stations. This thesis developed an optimization model, to determine the optimal number of shuttle buses and route allocation which minimize the overall subway and bus riders delay. The generated optimal solutions are sensitive to bus bay capacity constraints along the shuttle service corridor. The optimization model is integrated with a previously developed simulation tool that tracks the evolution of system queues and delays throughout the bus bridging process. A set of bus bridging policy guidelines were developed based on further analysis of the optimization model outputs using a Classification and Regression Tree (CART) model.

Keywords: Optimization
Public Transit
Rail Disruptions
Shuttle Buses
Advisor: Shalaby, Amer
Reducing Greenhouse Gas Emissions and Energy Costs in Canadian Buildings using Thermal Mass

In this thesis, two methods of using the thermal mass in Canadian buildings to reduce operational energy costs and greenhouse gas emissions (GHG) are investigated. The first is cooling commercial buildings with night ventilation. By comparing the climates of Canadian cities to the climates of urban centres with existing night-ventilated buildings, Vancouver and Edmonton were found to have strong night ventilation potential. The second method investigated is shifting heating demand in electrically heated high-rise residential buildings by varying the thermostat setpoint in order to use less expensive and less GHG-intensive electricity. A representative high-rise residential building was modeled with 16 retrofits in order to evaluate the most important building parameters. Model results indicated annual electricity cost savings of up to $34,000 and GHG savings of 20 Tonnes eCO2 in a 300-unit building. Further, findings indicated financial savings would increase if residential users were charged for their peak electricity demand.

Keywords: Demand Response
Fabric Energy Storage
Load Flexibility
Load Shifting
Night Ventilation
Thermal Mass
Advisor: Pressnail, Kim D
The Nutritional Implications of Household Food Insecurity in Canada

Household food insecurity affects 4 million Canadians and has negative implications for health and diet, as evidenced by the 2004 Canadian Community Health Survey (CCHS). The objectives of this thesis were to i) evaluate how household food insecurity status related to nutritional vulnerability among Canadian adults (19-64 y), using CCHS 2015 Nutrition; and ii) compare the nutritional vulnerability of Canadians (1-64 y) stratified by age-/sex-groups in moderately/severely food-insecure households between CCHS 2004 and 2015. Greater nutritional vulnerability was observed among adults on a gradient of worsening severity of food insecurity in 2015 and among older children and women in 2015 compared to 2004, but no differences were observed in the adequacy of men’s or children’s nutrient intakes over time. Considering the strong association between household food insecurity and poor health and the health-eroding effects of chronically poor nutrition, the nutritional vulnerability of individuals in food-insecure households should be addressed.

Keywords: Canadian Community Health Survey- Nutrition
Household food insecurity
Nutritional vulnerability
Prevalence of inadequacy
Usual intake
Advisor: Tarasuk, Valerie
Influence of Fines Content on Cyclic Resistance and Residual Strength of Base Metal Tailings

Stability of tailings dams is an important safety and economic issue for the mining industry. Liquefaction is the phenomenon in which a soil mass loses its shear strength following generation of excess pore water pressure. Liquefaction assessment is the main technical challenge for geotechnical engineers tasked to design tailings storage facilities. In this research project, a laboratory testing program was completed to assess the influence of fines content on the cyclic resistance and residual strength ratio of Base Metal Tailings through the critical state framework. Four gradations of Base Metal Tailings with fines content of 0%, 30%, 60% and 100% were tested in a direct simple shear apparatus. Cyclic resistance and post-cyclic residual strength were correlated to the state parameter. The influence of density, confinement, and fabric were also investigated.

Keywords: critical state
cyclic resistance
fines content
liquefaction
residual strength
tailings
Advisor: Ghafghazi, Mason
Microplastics and Other Anthropogenic Debris in Fish and Potential Implications for Human Exposures

Microplastics are an inconspicuous environmental threat that have received considerable attention due to global contamination and potential adverse ecological and human health impacts. Recent studies demonstrate that microplastics are ingested by aquatic organisms and can cause physiological and toxicological damage. As a result, concerns have been raised by government agencies and the public regarding microplastics in seafood. First Nations communities around Lake Simcoe have also expressed concern regarding microplastic contamination in their fish. In response, I measured contamination levels in fish from Lake Simcoe and found 93.2% (N=44) contained anthropogenic debris, the majority (86.8%) being fibers. The size of the fish was positively correlated with the quantity of anthropogenic debris found. In addition, I tested the potential for microplastic translocation in laboratory fish to inform exposure routes to humans. No translocation of microplastics was observed, suggesting the consumption of fish fillets is likely not a significant exposure pathway to humans.

Keywords: Fish
Human
Microplastics
Translocation
Advisor: Rochman, Chelsea M.
Characterizing the Physical Culture Conditions for Endothelial Cell Perpendicular Alignment to Flow

Flow-induced parallel alignment of endothelial cells (ECs) is replicated in vitro in macroscale parallel plate flow chambers (PPFCs), but with increasing application of microfluidic platforms to study EC biology and model ECs in organ-on-a-chip platforms, there is a need to better understand flow regulation of ECs in microscale platforms. Previous work in our labs found that EC monolayers confined in microchannels and PDMS stencils aligned perpendicular to the direction of flow in contrast to parallel alignment in macroscale PPFCs. The goal of this thesis was to elucidate the microfluidic culture parameters that condition for the confined EC phenotype. Perpendicular alignment to flow was observed in human umbilical vein ECs (HUVECs) across all tested physical and geometrical conditions and suggested that spatial control provides cues for a confined EC phenotype. This work demonstrated that perpendicular alignment to flow is a robust response in microscale-cultured ECs.

Keywords: Cell Alignment
Endothelium
Flow Shear Stress
Microfluidics
Organ-on-a-chip
Advisor: Young, Edmond W.K.
Simmons, Craig A.
Dwelling is Telling: Ruminating over School Challenges can Affect how Students with Strong Executive Skills Perform in Math

Elementary students with higher executive function (EF) tend to achieve better math outcomes. Although rumination is one maladaptive coping strategy that has been found to negatively affect EF, research exploring rumination’s impact on the relationship between EF and math performance (MP) in computation is lacking. We examined the relationship between caregiver-rated measures of EF and students’ MP as a function of student-reported level of rumination; rumination was hypothesized to moderate this relationship. In a sample of students from grades four to six (n = 69, mean age = 10.68), hierarchical regression analyses showed an interaction between EF and rumination in predicting MP. Students with EF deficits demonstrated lower MP, and this was moderated by level of rumination. Specifically, EF difficulties were associated with lower MP only among high ruminators; this was not observed among low ruminators. These results demonstrate the importance of teaching students how to appropriately address math challenges.

Keywords: Elementary School Students
Executive Function
Math Computation
Rumination
Advisor: Martinussen, Rhonda
Bedard, Anne-Claude
The Impact of the Move2Smile Program on Motor, Social and Emotional Development in Children Aged 3-4 Years

Today’s children and youth are facing three major challenges: (1) poor mental health, (2) physical inactivity and (3) lack of school readiness. Fundamental movement skills (FMS) and social-emotional learning (SEL) are two domains of development that underpin these challenges. The purpose of this study was the examine the acceptability and feasibility of Move2Smile, a program that targets both FMS and SEL, and to assess the impact of the program on FMS and SEL in children aged 3-4 years. Move2Smile was rated as acceptable and feasible by children, parents and the instructor. The intervention had a small-moderate effect on FMS and a small- large effect on SEL. Results from the focus group suggest that parents and children enjoyed the program and that the program was useful and effective at impacting FMS and SEL. Additional research is warranted to further explore the long-term impact of this program on the development of young children.

Keywords: Child Development
Early Intervention
Mental Health
Motor Skills
Physical Activity
Social-Emotional Learning
Advisor: Cairney, John
Stories of Collaborative Inquiry: Resistance and Negotiation in the Social Construction of Educator Knowledge

This qualitative practitioner research study delves deeply into the experience of a group of teachers who engaged in Collaborative Inquiry to consider a pedagogical shift to Community- Based Experiential Learning. Grounded Theory was used to theorize about their individual learning journeys within a socially-constructed learning environment. The conceptual framework which shapes this study calls educators to take up three views of Professional Learning: an outward view, focused on the structures of this professional learning experience; a shared view, framing the social construction of teacher knowledge of practice; and the inward view, foregrounding the hopes, wants, feelings and actions of the participants. These views foster and facilitate understanding of how school improvement is negotiated by teachers. The study reveals how teachers may overcome structural and contextual barriers within Professional Learning experiences through the alignment of their efforts to both personal and common values and beliefs about teaching and learning.

Keywords: Collaborative Inquiry
Community-Based Experiential Learning
Core reflection in professional learning
Grounded Theory
Narrative
Practitioner Research
Advisor: Broad, Kathryn
The Practice and Potential of Expressive Writing Groups

My research examines the potential of expressive writing groups in non-clinical settings for individuals navigating trauma, transition and life challenges. Writing as a tool for supporting mental health is not a new concept, however, there is renewed interest given the: track record of success; potential as a low-cost treatment; and flexibility for supporting isolated segments of the population. My mixed-methods qualitative research is part self-study narrative inquiry, probing my experience with expressive writing, and part case study analysis looking at the work of an organization offering volunteer facilitated expressive writing workshops in partnership with social service and community organizations. I analyze the data to advance knowledge in regards to how an expressive writing group functions, the role of the facilitator and how success is measured for the individual. This study produces valuable insight into models of expressive writing groups and their potential for healing and inspiring hope.

Keywords: community development
expressive writing
mental health
writing groups
Advisor: Mojab, Shahrzad
Evaluation of the Autoclave Expansion Test for Cement

The total MgO content of portland cements is limited in specifications to prevent abnormal expansion of periclase (MgO) to brucite (Mg(OH)2) transformation. In addition, in North American specifications, the ASTM C151 autoclave expansion test (AET) has been used since the 1940s as a rapid expansion (soundness) test to accelerate the periclase hydration. Within the last few years, cements have been found that failed the autoclave test while still being well below the chemical MgO limit, yet others with similar MgO contents passed the AET expansion limit. The primary objective of the current project was to determine if the AET is serving any purpose in protecting the consumer or is the chemical limit on MgO content sufficient? Based on the current research, it was determined that the AET is overly severe and provides an unrealistic ground for rejecting or accepting the portland cements.

Keywords: Autoclave Expansion Test (AET)
Cement MgO Content
Soundness
Advisor: Hooton, R Douglas
Ex-vivo Lung Perfusion Mediated Delivery of Rituximab to Clear Epstein-Barr Virus in Donor Lungs

Posttransplant lymphoproliferative disorder (PTLD) is a serious B-cell malignancy that can arise following solid-organ transplantation. PTLD is especially a risk in transplantations involving an Epstein-Barr virus (EBV)-positive donor and an EBV-negative recipient. In this study we utilize ex-vivo lung perfusion (EVLP), a novel platform for treatment, to administer rituximab to eliminate EBV latently infected B-cells in human donor lungs. We demonstrate that rituximab is effectively delivered using EVLP to B-cells residing in the tissue and lymph nodes of the lungs without inducing adverse effects or acute lung injury. Though the results demonstrate that rituximab does not mediate B-cell or viral depletion during perfusion, we show that the perfused monoclonal antibody can induce B-cell reduction 24 hours post-perfusion in-vitro. Our experiments illustrate the potential of EVLP as a platform to deliver monoclonal antibody therapies to expand the donor pool and make it safer.

Advisor: Humar, Atul
Cypel, Marcelo
A Stochastic Approach to Electromigration Checking for Chip Power Grids

Electromigration (EM) is a major reliability concern in modern chip design, especially due to continuous technology scaling. Existing methods for EM checking are inaccurate, and suffer from many shortcomings. Emerging solutions for EM checking are physics-based, which allow designers to track the stress evolution in the power grid interconnects, and hence, detect void formations which degrade conductivity. Korhonen's Model [15] is a physical model for EM degradation that has been extensively studied in the literature.The work in [2] uses the so-called Extended Korhonen's Model (EKM) to formulate the EM checking problem as a series of Liner-Time-Invariant (LTI) systems. This work is a first attempt to apply a stochastic approach to EKM. We propose a framework for a Stochastic Electromigration Simulation (SES) with multiple computational schemes. Our results show that the SES mitigates the optimism of the existing approach, providing more accurate chip lifetime estimates.

Keywords: Chip Power Grid
Electromigration
Stochastic
Advisor: Najm, Farid N.
Development and Validation of the Subjective Identity Concealability Scale

People with stigmatized identities are frequently the targets of prejudice. Being the target of prejudice has costly psychological consequences. For people whose stigmas are not visible, concealment offers an opportunity to avoid these consequences. However, concealment has its own negative consequences in multiple domains of psychological wellbeing. It is possible, however, that simply believing that an identity is concealable may be sufficient to minimize the psychological costs of stigmatization. Here, we introduce the construct of subjective identity concealability: the belief that an identity one holds is concealable from others. Across four pre- registered (https://bit.ly/33gaRvy) studies and an internal meta-analysis, we develop and validate a scale to measure individual differences in concealability beliefs and provide evidence that it predicts lower levels of the psychological costs of bearing stigma.

Keywords: Concealment
Identity
Prejudice
Scale Development
Stereotypes
Stigma
Advisor: Page-Gould, Elizabeth
Chasteen, Alison L
Student Perspectives on Course Choice in Ontario Secondary Schools

This research is concerned with how students experience the current Ontario secondary education system and their ability to choose from a variety of courses in relation to their own educational plans. This study identifies three main factors most important in secondary school course selection: (1) the influence of parents, (2) students’ interest in subjects, and (3) students’ past academic performance. The study is based on 19 interviews with first- and second-year university students in Ontario, Canada. Two main themes of secondary course selection were identified, (1) Self-Elimination from Fields of Study, and (2) Keep Options Open, as well as five subthemes. These themes are described using a framework of the three factors of course selection. Bourdieu’s concept of cultural capital is used as a theoretical tool to uniquely assess the experiences of students as they recount their secondary course selections in conjunction with the pressures of transitioning into postsecondary education.

Keywords: course choice
course selection
cultural capital
postsecondary transition
secondary curriculum structure
undifferentiated education system
Advisor: Childs, Ruth