VictorJuiz/thesis huggingface dataset:
Mitochondrial Dynamics in Mesenchymal Cells in Placental Development and Preeclampsia
Keywords: Hypoxia
Mitochondrial Dynamics
Placenta
Placental Mesenchymal Cells
Preeclampsia

Cellular health hinges on functional mitochondrial networks that are maintained by fusion protein Optic Atrophy 1 (OPA1) and fission protein Dynamin Related Protein 1 (DRP1). Preeclampsia (PE) is a serious pregnancy disorder where exuberant fission events contribute to trophoblast cells demise. Placental mesenchymal stromal cells (pMSCs) are critical for placenta development. We hypothesized that the mitochondrial dynamic events in pMSCs are kept in balance across gestation and that this balance is disrupted in PE. We discovered the low physiologic oxygen in the first trimester placenta produce small and functional mitochondria. Conversely, in PE exuberant fission were related to mitophagy. Healthy mitochondrial fission was attributed to the lysosome, whereas secondary lysosomes in PE degrade damaged mitochondria. In conclusion, during placental development physiologic changes in oxygen regulate mitochondrial dynamic events to maintain their function, however in PE excessive fission impair pMSCs function and contributes to poor placental development.
Long-term Caries Relapse following Dental Treatment under General Anesthesia
Keywords: caries relapse
dental caries
general anesthesia
pediatric dentistry
relapse
risk factors

This retrospective cohort study included 261 patients that received dental treatment under GA at a private pediatric dentistry practice in Southwestern Ontario. Data comprised of patient/caregiver and treatment factors for each subject. Caries relapse over long-term follow-up, along with associations with the collected variables were evaluated. Survival analysis found CR rates of 48% and 71% at 24 months and 48 months post-GA, respectively. Caries relapse was found to be significantly associated with active children, more multisurface composite restorations, and more remaining surfaces available for caries post-GA. Patients treated under GA in the mixed dentition were 75% less likely to experience CR compared to those in primary dentition. Caries relapse rates post-GA were high in this sample of children, suggesting that conventional surgical approaches to managing ECC is not controlling the disease process. Identifying risk factors for caries relapse may influence treatment and risk management decisions.
Investigating the Cellular and Molecular Correlates of Malignancy in Li-Fraumeni Syndrome
Keywords: Li-Fraumeni Syndrome
mTORC1
p53
Tumorigenesis
Tumour microenvironment

Li-Fraumeni Syndrome is a cancer predisposition syndrome associated with germline TP53 mutations. LFS patients are faced with a significant lifetime cancer risk, which necessitates the identification of cancer prevention strategies. Chemical mTORC1 inhibitors delay cancer onset and extend lifespan in LFS mice, suggesting that mTORC1 favors tumorigenesis in LFS. We show that LFS patient-derived fibroblasts harboring the R248Q p53 mutation exert a pro-tumorigenic influence when co-injected with cancer cells into mice. This influence was negated by rapamycin, suggesting that this pro-tumorigenic phenotype is mTORC1-dependent. To that end, mutant fibroblasts exhibit increased mTORC1 activity and vulnerability to mTORC1 inhibition compared to p53 wildtype fibroblasts. We further show that the secretome of mutant versus wildtype fibroblasts differs, and secretion of certain pro-tumorigenic cytokines is mTORC1-dependent. Our findings suggest that mutant-p53 driven mTORC1 activation promotes a functional dependency on mTORC1 signaling, revealing a vulnerability that may exploited to limit the oncogenicity of mutant p53.
Role of Notch Signaling in the Differentiation of Human Lung Progenitor Cells to Alveolar Epithelial Type II Cells
Keywords: Alveolar Epithelial Type II Cells
Lung Development
Notch Signaling
Organoids

Human lung development is a complex process guided by specific tissue interactions and cellular signaling. Attempts to generate cell-based model systems of the alveolar region of the lung have relied on recapitulating the biological environment within which these cell types exist. Utilizing an in vitro directed differentiation approach, this thesis demonstrates the efficient differentiation of human induced pluripotent and embryonic stem cells to NKX2-1+ lung progenitor cells and subsequent SFTPC+ alveolar epithelial type II (ATII) cells. With the aim of improving ATII cell differentiation efficiency, the role of Notch signaling throughout lung progenitor and ATII cell differentiation was investigated. Under the specific conditions tested, pharmacological inhibition of Notch signaling did not significantly improve our ability to derive ATII cells. However, a decrease in basal and secretory epithelial cell markers following Notch inhibition suggests that Notch signaling is important in the commitment of lung progenitor cells to specific proximal cell lineages.
Teaching Sustainability to Culinary Students: Graduating Sustainability-minded Chefs?
Keywords: Chefs de Cuisine
Culinary Arts Education
Food Culture
Food Studies
Food Systems
Sustainability

In 2016, The Ministry of Training, Colleges and Universities upon negation with food industry and culinary educational institutions’ stakeholders, mandated that culinary colleges across Ontario implement sustainability into their required program outcomes. Positioning the potential impacts of a chef’s actions on food production, consumer choice and food service operations’ management is crucial in assisting students to develop a sustainable mindset as future culinary leaders. This thesis aims to explore “The Sustainable Chef” course, offered by one of Toronto’s main culinary colleges, to assess its potential to assist culinary schools become vital sites to promote a new sustainable kitchen and food culture. Furthermore, graduating sustainability-minded chefs who are aware of their economic, social and environmental responsibilities as participants of the food system will help to drive change in the industry.
Menthol Mouth Rinsing Improves Cycling Performance in Females under Heat Stress
Keywords: Heat stress
Menthol
Perception
Thermoregulation
TRPM8

This study investigated the effects of a menthol mouth rinse on performance and physiological responses in female cycling athletes during a 30-km individual time trial (ITT). Participants (n=9) cycled for 30-km in hot conditions (30 ± 0.6 °C, 70 ± 1% relative humidity, 12 ± 1 km/h windspeed) on two test occasions using a menthol (MEN) mouth rinse (MR) occurring every 5-km. Perceptual responses (perceived exertion and thermal perception) were recorded at 5, 10, 15, 20, 25, and 30-km. The MEN MR significantly improved ITT performance by 2.3 ± 2.7% relative to PLA (p= 0.034, d= 0.85, 95% CI= 8.43 to 166.9). There were no significant differences in perceived exertion and thermal perception. These results demonstrate that a non-thermal cooling agent can improve physiological performance in moderately trained female cyclists with no change in perceived exertion or thermal perception.
Development of Electrochemical Sensors using Novel Nanocomposites
Keywords: carbon nanotubes
differential pulse voltammetry
electrochemical impedance spectroscopy
electrode modifications
graphene
nanocomposites

Modification of electrode surfaces with nanomaterials, polymer films, nanoparticles, nanocomposites, and self-assembled monolayers (SAMs) is a popular approach for improving the performance of electrochemical sensors. Nanomaterial modified electrodes are able to offer improved performance due to improvement in the electron transfer kinetics that occurs at the interface of these electrodes, increases in the electrochemically active surface area, electro-catalytic effects facilitated by the nanomaterials, and changes in the surface geometry. In this thesis, two such electrode modifications have been reported. In the first work, simultaneous electrochemical detection of ascorbic acid (AA), dopamine (DA), and uric acid (UA) was performed using a modified graphite paste electrode (MGPE) with epigallocatechin gallate (EGCG) and green tea (GT) powder. In the second work, multi-walled carbon nanotube-reduced graphene oxide (MWCNTrGO) nanocomposite-modified glassy carbon electrodes (GCEs) were used for the electrochemical detection of gallic acid-capped gold nanoparticles (GA-AuNPs) using differential pulse voltammetry (DPV).
Foundations of Children’s Sympathy: Recognition and Regulation of Anger and Sadness
Keywords: Anger
Children
Emotion recognition
Emotion regulation
Sadness
Sympathy

I tested how the recognition and regulation of specific distress-related emotions (i.e., anger and sadness) contribute to children’s tendency to feel sympathy. These relations were examined in an ethnically diverse Canadian sample of 4- and 8-year-olds (N = 300, n = 150 in each age group; 50% female). Across age groups, higher scores on both anger and sadness regulation independently predicted higher levels of sympathy. In addition, having a lower threshold to detect sadness predicted higher sympathy through the better regulation of sadness. In contrast, this indirect effect was not found for the anger-specific emotion variables. These results suggest that the nuances of children’s specific emotional capacities, particularly those related to sadness, are important to our understanding of the process by which children arrive at sympathy.
The CARD™ System for Improving the Vaccination Experience at School: Results of a Small-scale Implementation Project on Student Symptoms
Keywords: Children
Fear
Needle
Pain
School
Vaccination

Background: Many students fear vaccinations. We implemented a novel, multifaceted knowledge translation intervention in the school vaccination setting incorporating evidence-based coping strategies—The CARD™ System (C-Comfort, A-Ask, R-Relax, D-Distract)—and evaluated impact on knowledge, symptoms, coping strategies, and fidelity. Methods: Five experimental schools (ES) and five control schools (CS) in a controlled clinical trial. ES students completed a knowledge/attitudes survey during a CARD™ educational session and selected coping strategies before vaccinations. CS students received the usual vaccine lesson. Nurses recorded strategies used and students rated symptoms. Fidelity to CARD™ was evaluated. Results: CARD™ increased knowledge and coping strategy use. Distraction, deep breathing, support and privacy were most selected. CARD™ (vs. control) was associated with less high fear and high dizziness; pain and vaccination rate did not differ. High fidelity to CARD™ components was observed. Discussion: CARD™ improves student symptoms during school-based vaccinations. Research in different settings is recommended to confirm results.
When Word Learning Heuristics Meet Cross-situational Word Learning: A Comparison Between Monolingual and Bilingual Toddlers
Keywords: Bilingualism
Infant development
Monolingualism
Statistics
Word learning

Monolingual children reportedly rely more heavily on the Mutual Exclusivity Principle (MEP) than bilinguals in word learning. However, past work has only examined toddlers’ use of MEP after a single labelling. Here, we examine monolingual and bilingual 2-year-olds’ reliance on the MEP to learn novel colour labels. Importantly, cross-situational statistics linked a particular label to a particular colour – but not to a particular object. As a secondary question, we asked whether the fact that past studies have presented children with atypically-coloured objects (e.g., turquoise dogs) may have influenced how readily children attached novel labels to colour terms rather than objects. Preliminary results suggest that monolinguals and bilinguals were equally successful in learning novel colour labels, but learning only occurred when the objects were atypically-coloured. We conclude that researchers need to carefully consider the richness of children’s home learning environments to better understand development in diverse language settings.
A Multiplexed, Point-of-Care Detection System for Dengue
Keywords: biomarkers
Dengue
Flow Cytometry
Microfluidics

There is a growing need for diagnostic technologies which can provide accurate disease detection using sensitive, reliable, and inexpensive methods. A lot of research has been directed towards developing efficient point-of-care devices that enable the parallel detection of multiple analytes, in small-volume samples, with high sensitivity and in a short time. This motivates us to explore a platform for multiplex testing i.e. measuring multiple analytes at the same. Hence, we propose a microfluidics based optical detection system, for diagnosis of dengue biomarkers using bead-based immunoassays. Simultaneous detection of dengue antigen and antibody is crucial for prevention and diagnosis of dengue infection. The outcome of this study generates the first-generation prototype of a system capable of both classifying the microspheres and measuring the amount of specific biomarker.
Neck Strength-endurance Assessment: Potential Utility in Sport-related Concussion
Keywords: cervical muscle
concussion
neck strength
prevention
resistance training
sport related concussion/SRC

Neck strength may modify the risk of sport related concussion by controlling head acceleration during high risk impacts. The majority of literature evaluates maximal neck strength leaving other parameters less-explored. Thus, the purpose of this study was to assess neck strength-endurance in male and female athletes. We hypothesized: (1) females would perform poorer on the neck assessment compared to males; (2) athletes with a history of concussion would perform poorer than those with no history of concussion. Neck strength-endurance (flexion, extension, left and right flexion) was assessed in ninety-seven (n = 97) interuniversity athletes. The majority (68%) of participants failed one or more directions of the neck assessment, and most often in flexion (38%) and bi-lateral flexion (33%). There were no significant differences in neck strength-endurance between participants with and without history of concussion or between sexes. These results support assessing neck parameters in an attempt to reduce direction-specific deficits.
Going With Your Gut: How Does Believing Emotions are Helpful Versus Harmful Shape the Decision-Making Process?
Keywords: decision making
emotion
emotion beliefs

What we believe about emotions shapes how we approach emotions in our lives. I propose that individuals vary in their beliefs about whether emotions are helpful versus harmful for decisions and that these beliefs shape how individuals make decisions: those who believe emotions are helpful should be more likely to listen to their emotions when making decisions. I first validated a scale to assess these beliefs (Study 1) and then tested my hypotheses (Studies 2-4). People who believe emotions are helpful were more likely to habitually listen to their emotions when making decisions (Study 2), they had a stronger link between habitually seeking pleasure and impulsive decisions (Study 3), and a stronger link between feeling distressed and prosocial decisions (Study 4). These data suggest that people’s beliefs may be an important driver of how they make decisions: for people who believe emotions are helpful, the emotions they experience during decisions were stronger drivers of their actual decisions.
Reflectarray Antennas for Multiple-beam Satellite Applications
Keywords: Antenna
Reflectarray
Satellite communications

With the demand for high data rate communications systems continually increasing, there is a need for high-gain antennas which can meet increasingly difficult requirements while occupying less volume. This is especially true in satellite communications applications. Modern communications satellites use a coverage scheme which services a geographical region with a set of narrow spot beams which differ in frequency and/or polarization, allowing for increased capacity through frequency reuse. One solution to generate this coverage is to place a set of feeds in front of an offset reflector whereby each feed generates a separate beam. However, this generally requires multiple reflectors, which occupy mass and volume on the satellite that could be used for other services. In this thesis two methods are investigated that could potentially reduce the number of reflectors required. The results could also be useful for non-satellite applications which employ multiple-beam antennas that use feed displacement.
Alternative Spaces of Sex Education: A Look into the Lived Experiences of Young Queer Women
Keywords: Gender and Sexuality
Geographies of Education
LGBTQ+
Queer Geography
Sexual Health Education

The classroom is a formative space for young women to learn about sexuality and sexual health; however, sexual health education is often engrained in heteronormative expectations of sexuality, which exclude the experiences and health concerns of young queer women. This provokes the question of where, and how, young queer women learn about sexual health. This project draws on 29 in-depth, semi-structured interviews with young queer women who attended public high school in Toronto. The results illustrate the exclusion of queer sexual health in Ontario’s Grades 9-12 1998 sex education curriculum, and both the benefits and drawbacks of learning about sex and sexuality from friends, family, the Internet, clinics and community organizations. This analysis of spaces of education expands our knowledge of how and where young queer women learn about sexual health, with the hope to ultimately improve sexual health education for young queer women in Toronto.
Thompson Sampling with Belief Update for Piece-wise Stationary Multi-armed Bandit Problem
Keywords: Bayesian approach
Belief state
Multi-armed bandit problem
Non-stationary
Power prior
Thompson sampling

We propose new variants of Thompson sampling for an extension of the multi-armed bandit (MAB) problem, called the piece-wise stationary MAB, in which the reward distributions for the arms are piece-wise stationary and will shift at some unknown time steps. Several algorithms have been proposed, but they show poor performance or require large memory and computation. Different from existing works, we consider distinctive stationary periods as states, which are only partially observable, and estimate the distribution of the states, called the belief state. The integration of Thompson sampling and belief update leads to two variants of Thompson sampling: Thompson sampling with Belief Update - Finite (TS-BU-Fin) and Thompson Sampling with Belief Update - Infinite (TS-BU-Inf). Extensive empirical studies show that our algorithms outperform the state-of-the-art algorithms with advantages in memory and computation requirement.
Does Incidental Auditory Learning Facilitate Memory-guided Attention? A Behavioural and Electroencephalogram (EEG) Study
Keywords: attention
auditory
EEG
ERP
implicit
memory

Can implicit associations facilitate auditory target detection? Participants were exposed to audio-clips (half included a lateralized pure tone). Participants then took a surprise memory test in which they detected a faint lateralized tone embedded in each audio-clip and indicated if the clip was (i) old or new; (ii) recollected or familiar, and; (iii) if the tone was on the left, right, or not present when they heard the clip at study. The results show good explicit memory for the clip, but not for tone location. Target detection was faster for old than for new clips but did not vary according to the target-context associations. Neuro-electric activity revealed an old-new effect at midline-frontal sites as well as a significant difference between clips that had been associated with the location of the target compared to those that were not. The implications of these findings in the context of memory-guided attention are discussed.
The Association of Individual-level Characteristics with Aging and Health Care Utilization among Older Women and Men
Keywords: Aging
Gerontology
Health Care Utilization
Health Systems Use
Neighbourhood Quality

Older adults typically have the highest health care utilization of any age group. There are very few studies focused on older adults who are low-cost users (LCU) of the health care system. Understanding this population may be a key way to understand the determinants of healthy aging and wellness. In addition, the ways in which gender modifies the correlates of health-system use is explored. This thesis systematically reviews successful aging and health care utilization among older women and men. A study is then presented to better understand the sex-stratified individual-level factors associated with health care utilization for older adults. The results of these studies converged to suggest that certain health decisions made by clinicians, policy-makers, and older adults themselves, can be tailored to a person’s sex or gender. Further, the thesis highlights several sex/gender-based nuances in the health of older adults that should be explored in future research. Les personnes âgées ont généralement le taux d'utilisation des soins de santé le plus élevé parmi tous les groupes d'âge. Très peu d'études ont été menées sur les personnes âgées qui utilisent le système de santé à faible coût. Comprendre cette population pourrait être essentiel pour comprendre les déterminants du vieillissement en bonne santé et du bien-être. En outre, les moyens par lesquels le sexe modifie les corrélats de l'utilisation du système de santé sont explorés. Cette thèse passe systématiquement en revue le vieillissement et l'utilisation des soins de santé chez les femmes et les hommes âgés. Une étude est ensuite présentée pour mieux comprendre les facteurs individuels–stratifiés par sexe–liés à l'utilisation des soins de santé par les personnes âgées. Les résultats de ces études suggèrent que certaines décisions de santé prises par les cliniciens, les responsables politique et les personnes âgées elles-mêmes, peuvent être adaptées au sexe ou au genre d'une personne. En outre, la thèse met en évidence plusieurs nuances liées au sexe / genre dans la santé des personnes âgées qui devraient être explorées dans de futures recherches.
A Novel Near-infrared Spectroscopy Brain-computer Interface for the Detection of Emotional Valence in Children
Keywords: Access pathway
Affective state
Brain-computer interfaces
Near-infrared spectroscopy
Pediatric brain-computer interface

Brain-computer interfaces (BCI) are being investigated as an access pathway to communication for individuals with physical disabilities as they bypass the need for voluntary motor control to operate. However, to date, minimal research has investigated the use of BCIs for children. This thesis describes the development of a paediatric brain-computer interface to identify positive and negative emotional states from changes in hemodynamic activity of the pre-frontal cortex. To train and test the BCI, 10 typically developing children aged 8-14 underwent a session of emotion induction trials while their hemodynamic activity was measured with near-infrared spectroscopy (NIRS). BCI performance was evaluated both offline, using cross-validation, and online, using real-time prediction results. Offline differentiation rates were comparable to studies with adult populations, and online prediction was feasible, yet failed to surpass the 70% accuracy threshold of ‘effective’ BCI use. Interparticipant and intersession variability in BCI performance was also investigated.