VictorJuiz/thesis huggingface dataset:
Understanding Undergraduate Food Behaviours: A Spatiotemporal and Socioeconomic Analysis
Keywords: Financial constraints
Food Access
Food behaviours
Student health
Student Life
Temporal constraints

Food behaviours and food insecurity are complex topics, but there is minimal research on the food behaviours of post-secondary students, a population at higher risk of food insecurity. To understand the financial and temporal constraints faced by this population, this study uses a mixed-method approach. Ten semi-structured interviews were conducted, and an online survey was administered to 743 undergraduate students at the University of Toronto. The results of the analyses indicate students who live with their families’ face fewer barriers to accessing food, and students are more likely to report a healthy diet when they prioritize healthful food consumption. The findings demonstrate a need for more research on undergraduate student nutrition and lifestyle in relation to temporal and financial constraints. Such work will help universities and public health researchers gain a better understanding of how students purchase, prepare, and consume food, and ultimately contribute to student success and well-being.
An Analysis of the Prevalence and Predictors of Food Insecurity in Canadian Seniors
Keywords: Aged
Elderly
Food Access
Food Insecurity
Food Security
Senior

Food insecurity is a serious Canadian public health issue. As the Canadian population ages, it is important to know about the food insecurity experienced by seniors. Food insecurity among this group is a concern for its far-reaching effects on individual quality of life and health care services use and spending. Few studies have quantitatively explored the predictors of food insecurity among this growing group. This analysis examined changes in food insecurity rates among seniors using five waves of cross-sectional survey data from the Canadian Community Health Survey. Logistic and multinomial logistic models were employed to observe the effects of demographic, socioeconomic, social capital, and geographic factors on senior food insecurity. The results suggest that elderly food insecurity is complex and is influenced by income, demographic, health, social, and geographic factors. These factors should be accounted for in future policies surrounding food insecurity and poverty reduction among the elderly.
Nitrogen Doped Graphene Quantum Dots/Graphitic C3N4 Composites for Photocatalytic NOx Degradation
Keywords: carbon dot
carbon nitride
graphene
nitric oxide
photocatalysis
quantum dot

Photogenerated charge separation is critical for photocatalytic applications of graphitic carbon nitride (g-C3N4). Graphene carbon dots deposited on g-C3N4 are known to promote photogenerated charge separation at the interface by building heterojunctions. We fabricated a novel lateral composite by growing g-C3N4 around nitrogen-doped graphene quantum dots (NGQD) through carbon-nitrogen bonds on a tertiary nitrogen. The electronic coupling between NGQDs and g-C3N4 generates new bands localized at the interface to form an electronic gradient driving charges moving laterally along the π-p-π network and extending the photosensitive region. Higher photocatalytic activity was observed in the composite with an optimal NGQD loading rate of 1.66% compared to g-C3N4 leading to a greater initial NOx reduction.
A Robot Person Search Framework for Finding Dynamic Users in a Home Environment
Keywords: POMDP
Robot person search
Socially assistive robots

Socially assistive robots can provide assistance to seniors through social interactions at home. As these robots are not always collocated with the user, they need to first find the user before initiating an interaction. The majority of robot person search techniques in home environments do not consider dynamic user behaviours. This thesis presents a robot person search planner that considers evidence, which are objects at home that are associated with a user’s current location. By checking the presence or state of an evidence during the search, the planner can narrow down the current user location and find the person more quickly by searching fewer regions. An online Partially Observable Markov Decision Process (POMDP) solver is used to generate a sequence of actions that the robot can execute until the user is found. The planner outperformed techniques that do not consider such objects in both cases where the user is static and dynamic. The search planner was integrated into a mobile robot and tested in a home environment with real users.
Developing Activatable Photosensitizers for Fluorescence-Guided Photodynamic Therapy
Keywords: Activatable Photosensitizer
Azoreductase
Cancer
Carboxylesterase 2
Glutathione S-Transferase
Photodynamic Therapy

Photodynamic therapy (PDT) is increasingly being recognized as an attractive alternative to conventional forms of cancer therapies. Already clinically approved, this procedure is minimally invasive; by combining light, a small-molecule photosensitizer (PS), and molecular oxygen, reactive oxygen species can be produced in situ, causing damage to vital cellular components. Subsequently, cell death occurs by apoptosis or necrosis. In practice, after a PS has been administered, an appropriate wavelength of light is irradiated at tumors and surrounding tissue. However, since PSs lack selectivity and non-specifically localize, light irradiation also destroys neighboring healthy cells. To this regard, I developed activatable-PSs that extend beyond the conventional two-layered selectivity inherent to PDT by including biomarker-specific activation with enzymes: Glutathione S-Transferase, Carboxylesterase 2, and Azoreductase. With this heightened control, these PDT beacons will give a highly specific and localized therapeutic response by unquenching the probe to restore the PS’s native properties at the target site.
Building Information Modelling in the Canadian Architecture, Engineering, and Construction Industries
Keywords: adoption
augmented reality
bim
building information modelling
construction
virtual reality

Building information modelling (BIM) has gained popularity in the architecture, engineering, and construction (AEC) industries around the globe. Comparing to other leading nations, Canada has limited studies and initiatives on BIM. To fill the knowledge gap, the research will assess and quantify the adoption of BIM in the Canadian AEC industry, and identify relevant visualization technologies that facilitate the adoption of BIM. The first and second annual BIM surveys were reported for the Greater Toronto Area and Canada in 2018 and 2019, respectively. Key findings were highlighted in the thesis, such as the limited use of BIM in engineering, construction, and facility management. In addition, a content-based literature review was conducted for 126 journal articles from 2000 to 2018. Eight construction applications were identified and discussed. The contributions of this research include three conference papers, two technical reports, and a review article that will be submitted for peer review.
Cer-L9-Cit-2His: A Ratiometric Intracellular FRET-based Nickel Sensor
Keywords: Biochemistry
Fluorescence
nickel
Protein
sensor

Nickel is a trace metal that plays an important role in plants and microorganisms as an enzyme cofactor. Several strains of pathogenic bacteria such as Helicobacter pylori and Escherichia coli require nickel. Monitoring the available intracellular nickel concentrations would shed light on the homeostasis of metal ions and the physiology of these infectious bacteria. The goal of this research is to develop an intracellular Förster resonance energy transfer (FRET)-based nickel sensor that can monitor the nickel concentrations in real time. In this study, Cer-L9-Cit-2His, a modified zinc sensor was characterized. The zinc affinity was determined to be in the low nanomolar range, but further experimentation is required to determine the nickel affinity. The sensor exhibited a change in FRET response in BL21(DE3) E. coli cells that reported on changes to intracellular nickel concentrations. Modifications to the sensor will be required to improved nickel selectivity and the FRET response to nickel.
Modular Timber Concrete Composite System for Short Span Highway Bridges
Keywords: Bridge
Composite
Concrete
Timber
UHPFRC

An innovative concept for a modular timber concrete composite system for short span highway bridges has been designed and key components experimentally validated. The proposed system consists of a Ultra-High Performance Fibre Reinforced Concrete(UHPFRC) deck and glue-laminated timer (glulam) girders linked to act compositely together by reinforcing steel bar shear connectors. This composite system has light, stable modules that can be rapidly constructed on site with less special equipment. Simple design checks indicate that the concept satisfies all serviceability limit state(SLS) and ultimate limit state(ULS) requirements of the Canadian Highway Bridge Design Code. Pull-out tests characterized the embedment lengths of 20M steel bar connectors to be 10 bar-diameters in UHPFRC. Push-off tests determined the embedment lengths of the same bars to be 30 bar-diameters glued into the timber girders. The slip modulus of the connectors is determined to be 67 kN/mm. The stiffness of the crosswise self-tapping screw connectors were tested and found to be structurally insignificant in this application. The excellent tensile and cracking properties of the reinforced UHPFRC deck was experimentally verified. A small amount of reinforcement would further improve the ductility of the UPHFRC deck system.
Deconstructing a Nunavut Educators Experience: My Personal Journey towards Decolonial Praxis
Keywords: Autoethnography
Colonialism
Deconstruction
Education
Nunavut
Poststructuralism

Nunavut has committed to the implementation of a bilingual educational strategy. A contemporary legacy of colonialism in Nunavut, however, has complicated the implementation of a bilingual educational strategy contributing to important concerns about the presence of Inuit culture and languages. To disrupt my relationship to a contemporary legacy of colonialism, I ask how I may begin the process of decolonizing my experiences with cultural inclusion policy and language as a white male settler teacher? Applying a poststructuralist perspective that couples autoethnography and deconstruction I interrogate my subjectivity as a white male settler teacher. Several journal entries provide the basis for my analysis that through persistent questioning depart from familiar interpretation to produce openings regarding what could be happening and what could be. To conclude, I discuss both the implications and limitations of my analysis in relation to responsibility, emerging epistemology, and the potential to transition from reflection to action.
Photochemical Production of NOx/HONO from Nitrate on Indoor Surfaces
Keywords: Heterogeneous
HONO
Indoor
Nitrate
NOx
Photochemistry

There is increasing evidence that HONO is an important source of the unexpectedly high concentrations of indoor hydroxyl radicals. We have explored heterogeneous nitrate photolysis as a possible mechanism for NOx and HONO production indoors. We performed proof of concept studies by illuminating nitrated TiO2-slurry and painted surfaces with indoor light sources and found that both overall and relative concentrations of NOx and HONO depended on light source and surface type. We then investigated the effect of adding photosensitising pigments to the painted surface, increasing the relative humidity in the reaction cell, and illuminating real indoor films on painted surfaces. Finally, we explored water uptake by real indoor surface films and observed uptake curves indicative of phase shifts and/or 2D-3D transitions. These results highlight the importance of heterogeneous photochemistry to the indoor atmosphere and provide a basis for future studies of indoor nitrate photochemistry and indoor surface films.
Experiences of Stigma Among People with Osteoarthritis who Underwent a Total Joint Replacement of the Knee or Hip
Keywords: Osteoarthritis
Stigma

Stigma is recognized as having an important influence on health. There is limited literature addressing the experience of stigma among people with osteoarthritis (OA). The purpose of this study was to conduct a qualitative secondary analysis of data collected from patients with end-stage OA who underwent total joint replacement (TJR) of the knee or hip at three time points using the concept of stigma. A sub-sample of 11 participants was selected for inclusion. Thematic analysis was used, and analysis drew on Major et al.’s (2018) conceptual model. Results were organized around five themes that related to people’s high valuing of independence and stoicism and how these values were disrupted by OA. This led to stigma becoming a barrier to engagement in former activities. These findings suggest that people with OA may experience stigma that impedes recovery. Therefore, clinical care should include an understanding of this phenomenon. Further research should investigate how to better address patients’ experiences of stigma in practice.
Study of Oxidized Aluminum Anode and Application thereof in Organic Light-emitting Diodes
Keywords: aluminum anode
interface
light emitting diodes
organic light emitting devices
thin film
transition metal oxide

Organic light-emitting diodes (OLEDs) have emerged as promising alternatives to conventional light-emitting diodes (LEDs) in microdisplay applications due to their low power-consuming emissive nature which is specifically suited for solving view angle issues with a fundamentally low-cost manufacturing process. However, when OLEDs are coupled with a silicon backplane, the high optoelectronic performance is heavily hindered due to limitations on device configuration. In this thesis, we discovered an ex-situ fabrication method to utilize aluminum’s electrical and optical properties to enhance the luminance characteristic of the OLED. By employing the UV-ozone oxidation of thermal evaporated aluminum thin films in conjunction with various transition metal oxides as part of the anode, highly efficient top-emitting OLEDs were fabricated. Given the large thickness of the aluminum oxide, we explored the possibility of a diffusion reaction between the transition metal oxide and the underlying aluminum to be responsible for enabling the emission of the OLED.
Disruption of the Interaction between α7 Nicotinic Acetylcholine Receptor and Glutamate N-Methyl-D-Aspartic Acid Receptor Exerts an Anti-depressive Effect
Keywords: Antidepressant
Depression
nAChR
NMDA
Peptide
Receptor interaction

Major depressive disorder (MDD) has become a serious mental health problem within society, imposing a heavy burden on patients and their families. However, our current anti-depressive treatments provide limited benefits and are associated with adverse effects. Previous research has shown direct protein-protein interactions between α7 nicotinic acetylcholine receptor (nAChRs) and glutamate N-Methyl-D-Aspartic Acid (NMDA) Receptors. Since both receptors are involved in the pathophysiology of MDD, we hypothesized that disruption of this protein interaction, via a novel interfering peptide, would demonstrate an anti-depressive effect in animals. Hence, this receptor interaction may have a crucial role in MDD, and interfering peptide intervention could present a novel therapeutic for the treatment of patients with MDD.
Investigating the Effects of the Medulloblastoma Secretome on Neural Stem Cell Function
Keywords: Medulloblastoma
Neural stem cells
Neurogenesis
Pediatric brain tumor

Medulloblastoma (MB) is the most common malignant pediatric brain tumour. MB survivors are often left with cognitive deficits that persist throughout life, which are attributed to the side-effects of treatment and other factors such as hydrocephalus. However, recent studies suggest that nearly half of the patients spared of radiation still develop cognitive impairments. Neural stem cells (NSCs) in the ventricular-subventricular zone (V-SVZ) contribute to oligodendrogenesis and therefore to cognitive development. This V-SVZ niche is supported by local and systemic circulating growth factors. Here, I have examined whether the MB secretome directly affects NSC function in the postnatal V-SVZ. The MB secretome results in a decrease in neural precursor cell proliferation one week after a single intraventricular administration. As well, olfactory bulb neurogenesis was perturbed in mice with MB xenograft tumours. These findings demonstrate that the MB secretome can act on V-SVZ NSCs and perturb their function, potentially disturbing forebrain development.
Accelerated Discovery of New Materials for Oxygen Evolution Reaction
Keywords: Catalysis
High Throughput Screening
Machine Learning
Oxygen Evolution Reaction

This thesis investigates new electrocatalysts for the oxygen evolution reaction, which is critical for the feasibility of water electrolysis. The evolution reaction can be used to store renewable energy that is produced intermittently. The discovery of new electrocatalysts is hindered by the vast chemical space. By developing a high-throughput method, I first targeted a group of promising crystal structures and narrowed the searching space for the oxygen evolution reaction using computational screening based on density functional theory. A machine learning algorithm was then implemented based on the database constructed. The 1st ionization energy and the atomic number were found to be accurate descriptors for the adsorption energy of 𝑂𝐻 and 𝑂𝑂𝐻. I used these two parameters as input for the random forest regressor for predicting the adsorption energies on doping materials. This method has thus far identified around 400 doping materials for a single type of crystal structure. The predicted catalyst properties agree with the reported experimental results and accelerate finding the top candidates for experimental validation. I validated the predicted results with reported data to ensure that the models are grounded in practice and consistent with experiments.
Compress-forward Relaying for Interference Mitigation
Keywords: Cooperative Relay
Interference
Relay

Users in a cellular network may be adversely affected by interference induced by neighboring base-stations. The deployment of cooperative relays to assist these users is considered in this thesis. Correlation of the interference between the relay and user may be exploited by the relaying scheme to mitigate the adverse effects of interference. The main contributions of this thesis are a theoretical analysis of the problem and an implementation using software-defined radios (SDRs). The theoretical results justify the use of cooperative relays for interference mitigation within a cellular network. Implementation considerations are studied for this particular network configuration, such as the benefit in exploitation of the redundancy of the signal of the relay and destination with the presence of interference. The SDR implementation results demonstrate the feasibility of such an approach for a three-node relay network with a single source of interference.
Incorporating Regulatory Focus in Product Design Towards Pro-environmental Behaviour
Keywords: cognitive state detection
product design
pro-environmental behaviour
regulatory focus

A traditional approach to reducing energy consumption focuses on increasing the energy efficiency of products. However, the energy saved by increasing product’s energy efficiency can be easily overridden by inappropriate usage behaviours. This phenomenon emphasizes the importance of users to engage in pro-environmental behaviour (PEB). Few effects were achieved on promoting PEB with environment-related messages, raising focus on fostering PEB through human-product interactions. This thesis aims to integrate the regulatory focus theory (RFT), a goal-pursuit psychology theory, with product design strategies towards interventions to promote PEB. Individuals experience regulatory fit effect when information received aligned with their regulatory focus. Regulatory fit effect on PEB was examined. Small sample size and confounding individual differences preclude decisive conclusion. Measurement of individuals’ regulatory focus through intervention is necessary to utilize regulatory fit effect. Various interventions were explored. No reliable measurement model was constructed, but the thesis provides insights for future studies.
Development of a Patient-derived Hepatitis C Viral Pseudo-particles Library
Keywords: HCV cDNA library for real viral variants
HCV pseudo-particles-luciferase
Hepatitis C
Neutralization mediated by antibodies
Purification of viral derivatives (HCVpps VLPs)
Viral entry processes

The evaluation of neutralization potency for the Hepatitis C (HCV) targeting antibodies and infectivity of the virus remains a difficult task because HCV is highly genetically variable. There is an urgent need to develop an efficient in vitro system consisting of a library of heterogeneous HCV cDNA clones, representative of the real viral variants. In our lab, we developed a HCV pseudo-particles (HCVpps) library derived from 120 infected HCV patients. The aim of this study is to investigate whether these HCVpps can mimic in vivo viral interaction in Huh-7 cell culture. My findings have indicated that anti-E2 antibody was highly specific for its E2 antigen and it did not neutralize other variants of virus. In addition, the sequence analysis data has indicated that our HCV cDNA clones have sequences that are highly distinct from each other and they can be used to build upconstitute the cDNA library representing different HCV variants.
Protection from Endoplasmic Reticulum Stress and Apoptosis via PPARδ and Bcl-2 in Breast Cancer
Keywords: ABT-199
Apoptosis
Breast Cancer
Endocrine Therapy
ER stress
Tamoxifen

Estrogen receptor positive breast cancer accounts for the majority of breast cancer cases. Anti-estrogens, such as tamoxifen, are used to prevent the growth and survival of these cancer cells. However, patients often develop resistance to this drug due to dysregulated apoptosis. The overexpression of either Bcl-2, an anti-apoptotic protein, or PPARδ, a nuclear receptor protein, allows cancer cells to evade endoplasmic reticulum stress and survive. MCF-7 cells were used to investigate how dysregulated apoptosis contributes to tamoxifen resistance. Synergistic protection was observed in cells that overexpressed both PPARδ and Bcl-2, suggesting that the proteins work through different pathways. This implies that patients would require different treatments depending on the expression levels of Bcl-2 and or PPARδ in their tumours. In addition, the Bcl-2 inhibitor, ABT-199, was unable to sensitize cells that overexpressed Bcl-2 to drug treatments that elicit endoplasmic reticulum stress, revealing a novel BH3-independent mechanism of resistance through Bcl-2.
Aerodynamic Focusing of an Abrasive Air Jet
Keywords: Abrasive Air Jet
Aerodynamic Focusing
Computational Fluid Dynamics
Micro-Machining

In order to decrease the size of the eroded footprint resulting from abrasive jet machining, the aerodynamic focusing of an abrasive particle jet was investigated. For an abrasive jet from a slot nozzle, the best focusing employed a pair of bounding air jets tilted 60° to the abrasive jet, and impinging it approximately 10% of the standoff distance from the workpiece. An optimum bounding jet pressure existed to achieve the maximum focusing, resulting in a machined channel width reduction of up to 16 % with a corresponding depth increase of 84%. A novel apparatus was constructed to generate an annular bounding jet impinging a central abrasive jet formed from a round nozzle. However, aerodynamic focusing in this case could not be achieved due to the large stagnation zone that formed near where the annular jet impinged. Computational fluid dynamics simulations were used to understand the mechanics of particle focusing.