VictorJuiz/thesis huggingface dataset:
Exploring the Influence of Strength and Load on Back Squat Kinematics During Sets to Volitional Failure

Varsity athletes often train and compete in high fatigued states. Under those conditions, their movement could be affected. With continuous exposure to a different movement pattern due to fatigue, athletes could ingrain movement patterns that are undesirable for performance or risk of injuries. The purpose of this thesis was to assess: 1) change in lower extremities joint kinematics within a set to volitional failure, 2) the influence of strength and load on the magnitude of change in joint kinematics. Dependent measures included change in peak ankle dorsiflexion angle, knee flexion angle, hip flexion angle, and trunk flexion angle while the independent measures were the load (55% 3RM versus 85% 3RM), 3RM and time (onset and end of each set). It is hypothesized that athletes with a greater 3RM will demonstrate the greatest change in movement, especially in the low load condition.

Keywords: kinematics
squatting
strength training
task failure
Advisor: Frost, David
Effects of Hypoxia on Drug Transport in the Developing Human Blood-brain Barrier: Implications for Fetal Brain Protection

P-glycoprotein (P-gp) and Breast Cancer Resistance Protein (BCRP) are two multidrug resistance transporters expressed at the blood-brain barrier (BBB). They confer protection against entry of harmful molecules into the fetal brain. The fetus develops under relatively low oxygen concentrations; however, pregnancy disorders may lead to even lower intrauterine oxygen levels. We investigated the effects of hypoxia on transporter expression in early- and mid-gestation human fetal brain endothelial cells (hfBECs). Results indicate a decrease in BCRP protein and activity under hypoxia in early-gestation hfBECs. Mid-gestation hfBECs exhibited an increase in P-gp and BCRP activity following hypoxia. These findings suggest a decrease in fetal brain protection in early-pregnancy, but a potential protective effect of the transporters at the BBB during mid-gestation, possibly modifying transfer of various substrates across the fetal BBB under hypoxia. Future studies are required to investigate the mechanisms by which hypoxia modulates P-gp and BCRP at the fetal BBB.

Keywords: Blood-brain barrier
Brain development
Hypoxia
Multidrug Resistance Transporters
Advisor: Matthews, Stephen SM
Handling Qualities of a Regional-Class Hybrid Wing Body Aircraft

The handling qualities ratings (HQRS) of a hybrid wing body (HWB) aircraft optimized for regional operations were evaluated by test pilots flying takeoff and landing tasks. The goal of the project was to determine if the use of a limited number of stability and control constraints during optimization produced a configuration with acceptable HQRS without stability augmentation. An aerodynamic lookup table model was created using computational fluid dynamics tools to solve the RANS equations and implement the VLM. This model was integrated into a 6DOF MATLAB Simulink model and compiled as a real-time executable used in the UTIAS full flight simulator. Linearized aerodynamic models were used to predict HQRS using the methodology specified in MIL-STD-1797A. A stability augmentation system (SAS) was designed to improve the HQRS. The pilot evaluations determined that HQRS were acceptable with the SAS but the aircraft would be dangerous to fly if failures were to occur.

Keywords: Blended Wing Body
Handling Qualities
Hybrid Wing Body
Optimization
Simulator
Stability Augmentation
Advisor: Grant, Peter R.
Development and Evaluation of an Educational Program for Community Pharmacists on Opioid Stewardship in Acute Pain

The prescribing of excessive quantities and doses of opioids for acute pain can increase the risk of harm for patients and their families. Community pharmacists can play a role in preventing harm associated with opioids in acute pain by providing opioid stewardship activities such as dispensing smaller quantities, advising on safer daily doses and counselling on safe storage and disposal. An educational program for community pharmacists was designed to give community pharmacists the knowledge, confidence, and motivation to provide these activities in their everyday practice. Surveys were used to evaluate the program and showed that it was well received. Survey results also suggested that the program had a positive impact on participants’ confidence, motivation, knowledge, and intention, however it is not known if this translated into a change in pharmacists’ behaviour.

Keywords: Education
Opioids
Pharmacy
practice
Advisor: Sproule, Beth
Measuring the Turnover of Docosahexaenoic Acid in the Brain, Liver, Plasma and Adipose Tissue Using Compound Specific Isotope Analysis

Through experimental evidence, docosahexaenoic acid (DHA) is known to be essential for brain growth and function, as well as for maintaining brain health. Our laboratory has explored an alternative, cost-effective technique, called compound specific isotope analysis (CSIA) that takes advantage of natural differences in carbon-13 content (13C/12C ratio or δ13C) of the food supply to better understand tissue DHA metabolism. However, previous models have been limited by the selection of timepoints and variations in DHA pool sizes, preventing accurate measures of DHA turnover. The research carried out in this thesis explores the use of CSIA by using a diet switch study to trace tissue fatty acid metabolism by taking advantage of natural variations in the δ13C-DHA of algal and fish DHA sources while maintaining stable DHA pools to assess tissue DHA turnover rates. In addition, we used an enriched 13C DHA treatment diet (spiked-DHA) to test its use in diet switch studies. First, we showed that brain half-lives were consistent with previously published studies using various methodologies. Second, by incorporating additional early time points and maintaining DHA pool sizes, we were able to accurately calculate DHA turnover rates in tissues other than the brain including the plasma and liver. Lastly, by using an enriched (uniformly labeled 13C) DHA source (very high δ13C), we validated its utility in diet switch studies.

Keywords: brain
diet
docosahexaenoic acid
fatty acid metabolism
mass spectrometry
omega-3 fatty acids
Advisor: Bazinet, Richard P
A Guideline for the Implementation of Model-Based Functional Hazard Assessment and its Integration with Model-Based Systems Engineering

This thesis presents two papers on the topic of implementing model-based functional hazard assessment (FHA) and integrating this with model-based systems engineering (MBSE) activities. The first paper presents a UML profile extension, the FHA Profile, which enables the modelling of failure conditions in the system model. A process for generating an FHA report using model data is also introduced. Finally, a demonstration using safety data for a wheel braking system is performed to show the profile in use. The second paper presents the MBFHA framework which details the language, methods and tool needed to perform model-based FHA. The framework introduces: an overall workflow specifying how MBSE and model-based FHA activities can be integrated, a process for generating safety requirements, and a guideline for tool selection. A proof-of-concept model is also presented using generic safety data for a landing gear extension and retraction system to demonstrate the framework in use.

Advisor: Olechowski, Alison
Disruption of Pseudomonas aeruginosa Biofilms by Murine Alveolar-Like Macrophages Secreting Psl Glycoside Hydrolase (PslG)

In Cystic Fibrosis (CF), high morbidity and mortality arise from biofilm accumulation due to colonization of the bacterium Pseudomonas aeruginosa in the lungs. These biofilms are resistant to the immune system and antibiotics. I considered that stem cell-derived Alveolar-Like Macrophages (ALMs) that have been genetically modified to secrete the glycoside hydrolase enzyme PslG which is capable of disrupting P. aeruginosa biofilms, may have potential as a novel CF therapy. I have characterized the secretion kinetics of PslG-ALMs in-vitro. PslG-ALMs can disrupt mature biofilms of the P. aeruginosa lab strain PAO1 and patient isolates in-vitro. After intratracheal delivery, PslG-ALMs survive and secrete active PslG in the airways of healthy mice. PslG-ALMs do not elicit an antibody response in mice. These results of PslG-ALMs against P. aeruginosa biofilms in-vitro and in-vivo in mice support future investigation of the potential of ALMs as a dual therapeutic and drug-delivery technology.

Keywords: Biofilm
Cystic Fibrosis
Innate Immune System
Lungs
Macrophage
Pseudomonas Aeruginosa
Advisor: Post, Martin
A Cross-Sectional Study of COVID-19 Knowledge, Attitudes, and Practices Among Black Communities in the Greater Toronto Area

BackgroundAdherence to preventative health practices is tied to knowledge and attitudes. The COVID-19 knowledge, attitudes, and practices (KAPs) among Black communities has had limited testing in a Canadian context. ObjectivesTo explore the associations between health literacy, sociodemographic variables, and KAPs and test their hypothesized relationships. DesignCross-sectional survey. MethodsAn online questionnaire was completed by Black adults living in the Greater Toronto Area. Associations between KAPs, health literacy, and sociodemographic variables were assessed using descriptive tests. A multivariate logistic regression model was used to examine predictors of high preventative practices. ResultsOf the 169 respondents, most had high knowledge scores (80.5%), low attitudes (85.2%), and high COVID-19 preventative practices (82.2%). Hotspot status, working from home, and high health literacy were found to be independent predictors of high preventative practices. ConclusionThis study provides new knowledge that advances understanding of the COVID-19 KAPs of Black communities in a Canadian context.

Keywords: Black communities
Health behaviours
Advisor: Papadakos, Janet
Development of a Clinically Feasible Functional Electrical Stimulation System with Visual Feedback Training to Improve Standing Balance

Individuals with spinal-cord injuries (SCI) are at an increased risk of falling due to their impaired ability to maintain balance. Our research group has developed a closed-loop visual-feedback training (VFT) system coupled with functional electrical stimulation (FES) for rehabilitation of standing balance (FES+VFT system); however, clinical usage of this system is limited by its use of force plates, which are expensive, cumbersome, and not easily accessible. For my thesis project, I 1) evaluated the validity of alternative sensors to the force plate for assessing postural balance and 2) developed and evaluated an updated FES+VFT system which uses the best alternative determined for real-time postural feedback. A clinically feasible version of the FES+VFT using the depth camera was developed and tested with ten able-bodied participants. The results of this research contribute to a more accessible standing balance rehabilitation system for individuals with incomplete SCI.

Keywords: Closed-loop
Functional electrical stimulation
Rehabilitation
Standing balance
Visual-feedback training
Advisor: Masani, Kei
You Shall Call Me Yahweh: The How and Why El Came to be Known as Yahweh (Exod 3:1-15)

You shall Call Me Yahweh: The How and Why El Came to be Known as Yahweh (Exod 3:1-15)MA -Near & Middle Eastern Civilizations 2023 Thandazani Mhlanga Department of Near and Middle Eastern Civilizations University of Toronto Moses’s encounter with Yahweh at Horeb and the corresponding exodus have arguably attracted academic debate for a longer period than most biblical passages. In this thesis, it is the author’s intent to conduct a nuanced rhetorical criticism of Exodus 3:1-15 that considers form criticism and the oral tradition undergirding the text. A new all-encompassing interpretive system is also suggested and utilized for the purposes of sharpening our interpretive precision and enhancing our sensitivity and comprehension of the text. Through this nuanced multi-layered critical approach, it becomes evident that the story of Moses’s encounter with El, the God of Your fathers, in Exodus 3:1-15, is an etiological myth of Yahweh as the innate character of El. Furthermore, the corresponding Sitz im Leben of this switch from El to Yahweh brings to light the often elusive and, consequently, ignored relationship between the story and the storyteller.

Keywords: Ancient Israelite religion
El to Yahweh
Folklore and Orality
Moses
Rhetorical criticism
The God of the Fathers
Advisor: Demson, Leslie
Metso, Sarianna
Bioengineering Vascularized Porcine Free Flaps by Perfusion-Decellularization and Recellularization

Large volume soft tissue defects greatly impact patient quality of life and function while suitable repair options remain a challenge. Engineered tissues using decellularization/recellularization techniques may be a potential solution to circumvent issues of donor site morbidity or tissue availability associated with conventional free flap reconstruction. We developed and optimized a protocol to decellularize four vascularized porcine flaps within a custom designed perfusion-bioreactor and characterized the resultant extracellular matrix (ECM) components using both qualitative and quantitative techniques. Following decellularization, we designed a perfusion-based recellularization strategy by seeding a co-culture of human umbilical vein endothelial cell (HUVEC) with mesenchymal stromal cells (MSC) onto a decellularized omentum and tensor fascia lata flap. Our methods demonstrated evidence of cell attachment with early evidence of a regenerated neo-endothelium. Altogether, our described methods to engineer vascularized flaps scaffolds may help to obtain an “off-the-shelf” tissue option for application in large soft tissue defect reconstruction.

Keywords: Regenerative Medicine
Tissue Engineering
Translational Medicine
Advisor: Haykal, Siba
Waddell, Tom
Evaluating Serum Urate Monitoring amongst Older Adults with Gout Initiating Urate Lowering Therapy in Ontario, Canada

Serum urate (SUA) monitoring plays an important role in gout management. This thesis examined whether older adults with gout received SUA monitoring after initiating urate lowering therapy (ULT). Among a population-based cohort of 44,438 gout patients who initiated ULT between 2010 and 2019, 64% had SUA testing within six months. SUA testing was lowest in 2010 (56%) and increased over time to 71% by 2019. Increasing patient age, rural residence, low socioeconomic status, male ULT prescriber, chronic obstructive pulmonary disease and prior cardiovascular event(s) were associated with lower odds of SUA testing. Patients with kidney disease, hypertension, diabetes, ULT prescribed by rheumatologists, at lower starting doses, in more recent years and who received concurrent colchicine/oral corticosteroids had higher odds of SUA testing. These findings suggest variations in care and the need to develop/disseminate Canadian clinical guidelines for gout management to reduce care variation and potentially improve gout clinical care.

Keywords: Crystal Arthropathies
Gout
Health Services Research
Quality of Health Care
Rheumatology
Advisor: Widdifield, Jessica
Identifying Probiotics that Modulate Mitophagy in Models of Mitochondrial Dysfunction

Disruption of mitophagy in neurons is linked to Parkinson’s disease (PD), which is a multifactorial neurodegenerative disorder that currently has no cure. The neuroprotective effect of probiotics has become an emerging field of study due to growing evidence of the link between the health of the GI tract and the CNS. In various animal models and clinical trials, probiotic supplementation led to the alleviation of PD-like symptoms, while the mechanism of function remains unknown. The aim of this thesis was to identify probiotics that can potentiate mitophagy under mitochondrial stress and determine the active component(s). Utilizing cellular assays and a Drosophila model of PD, I validated that the probiotics Saccharomyces boulardii CNCM-I-1079 and Lactococcus lactis R1058 can induce Parkin-dependent mitophagy under mitochondrial stress, and only probiotics with mitophagy modulating ability shown neuroprotective effects. I also demonstrated that the small molecule MI6C is an active component released by CNCM-I-1079 and R1058 that induces mitophagy.

Keywords: mitophagy
Parkin
Parkinson disease
probiotic
Advisor: McQuibban, Angus A.M
Comelli, Elena E.C
Combined Physiotherapy and Deep Brain Stimulation to Improve Independent Community Mobility in Parkinson’s disease

Despite overall improvements in motor function, studies have reported that deep brain stimulation (DBS) alone may not increase community mobility and may be associated with balance and gait instability and increased rate of falling in individuals with Parkinson’s disease (PD). The overall objective of this study was to determine if DBS combined with physiotherapy is effective for improving safe, independent mobility in the community in individuals with PD compared to individuals receiving DBS only. This is a single-center, single-blind non-randomized controlled study, whereby individuals receiving DBS were allocated to receive either physiotherapy three times per week for eight weeks or no intervention (control group). The findings from this study suggest that physiotherapy combined with DBS may be effective in improving balance and gait functions and reducing near-falls in PD compared to individuals receiving DBS only. Studies involving larger sample sizes are needed to determine its effect on overall community mobility.

Keywords: balance
deep brain stimulation
mobility
Parkinson's disease
physiotherapy
rehabilitation
Advisor: Fasano, Alfonso
The Influence of Sex on Fiber-Specific Morphological and Metabolic Characteristics of Human Skeletal Muscle

We evaluated the influence of sex on whole muscle and fiber-specific indices of mitochondrial content, capillarization, and muscle morphology of untrained adults. Resting muscle biopsy samples obtained from age- and body mass index-matched females (n=14) and males (n=13) were analyzed via immunofluorescence and Western Blotting. Type IIa (p=0.003) and IIx (p=0.002) fibers, but not type I fibers (p=0.24), were smaller in females compared to males. Compared to males, females had a lower proportionate area of type IIa fibers (p=0.02) and a greater proportionate area of type I fibers (p=0.01). There were no differences between sexes in most whole muscle or fiber-specific indices of capillary and mitochondrial content; however, increased capillary density in type I vs. type II fibers was observed in males (p=9.37x10-5) but not females (p=0.76). In conclusion, we demonstrate that type I and type II muscle fiber morphology, but not oxidative capacity, differs between untrained males and females.

Advisor: Gillen, Jenna B
Mechanism of Deregulated Osteoclast Activity under Estrogen-withdrawal

Estrogen (17β - estradiol) deficiency post-menopause alters bone homeostasis whereby bone resorption by osteoclasts exceeds bone formation by osteoblasts, leading to osteoporosis in females. We established an in vitro model of estrogen-withdrawal (E2-WD) with osteoclasts derived from the mouse macrophage RAW 264.7 cell line and utilized it to investigate the mechanism behind deregulated osteoclast activity post-menopause. We found that a greater population of osteoclasts that underwent E2-WD contained a podosome belt, which is necessary for osteoclasts to adhere and resorb bone, than the osteoclasts exposed to estrogen (E2) continuously. Our results show that, compared to osteoclasts that received E2 continuously, those that underwent E2-WD had shorter podosome lifespans, reduced RhoA activation, and a faster rate of microtubule growth. Thus, altered podosome and microtubule dynamics induced by the withdrawal of estrogen supports podosome belt assembly/stability in osteoclasts, which may explain their enhanced bone resorption activity.

Advisor: Harrison, Rene E
Exploring the Role of Iron during Neisseria meningitidis Pathogenesis

Neisseria meningitidis is a human-restricted bacteria that can cause invasive meningitis and septicemia that can lead to lifelong morbidities and death, albeit its common asymptomatic colonization state. Not much is known of the factors that trigger the meningococci to transition into invasive disease, due to its human-restricted nature that makes infection studies difficult in wildtype mice. I utilize mice expressing human CEACAM1, transferrin and lactoferrin as a model to reveal the factors that are involved in the pathogenesis of N. meningitidis. I show that the co-expression of human CEACAM1, transferrin and lactoferrin significantly improves colonization compared to human CEACAM1 alone, and that transferrin utilization may be more advantageous over lactoferrin during early colonization. Lastly, I reveal that FetA-dependent xenosiderophore usage may be actively involved during meningococcal colonization. Collectively, this study unveils the importance of transferrin and lactoferrin during meningococcal colonization and provides an improved model of meningococcal pathogenesis in mice.

Advisor: Gray-Owen, Scott D.
Alkali-Activated Materials After 5 Years of Exposure to Alkali-Silica Reaction and Sulfate Attack

Cement is one of the most widely adopted building materials in the world, due to versatility, efficiency and cost. Cement production, however, is a big contributor to CO2 emissions worldwide. Alternatives are available, based on recycled building materials, industrial by-products, natural minerals, among others, but these are not always as cost-effective and durable as Portland Cement. The processes responsible for the long-term degradation of concrete, made from Portland Cement or otherwise, include corrosion, carbonation binder-aggregate reactions, sulfate attack among others. This work assesses the long-term durability of alkali-activated alternative binders, namely slag, fly-ash and metakaolin, as compared to regular Portland Cement in concrete. The main areas of focus are Alkali-silica reaction (ASR) and sulfate attack. Six mix designs are studied under ASR conditions, two using Portland Cement as the binder, and four with slag as the alkali-activated precursor. For sulfate, Portland Cement, slag, fly ash and metakaolin are investigated after 5 years exposed to magnesium sulfate. The performance was investigated by length measurements, microscopic investigations, and chemical analyses using SEM-EDS equipment. It is found that ASR is heavily related to the calcium content of the binder, with higher ASR expansion the higher the Ca content. Under sulfate exposure, the main degradation process is the decalcification of the binder, weakening the matrix and allowing the formation of gypsum.

Advisor: Peterson, Karl