VictorJuiz/thesis huggingface dataset:
The Relationship between Periarticular Muscle Properties and Knee Pain in Non-overweight Postmenopausal Females
Keywords: Fat infiltration
Females
Knee osteoarthritis
Non-overweight
Periarticular muscle
Postmenopausal

Lower muscle and greater fat infiltration in the lower limbs have been associated with pain and functional limitation in older adults with knee osteoarthritis (OA). It is unknown how muscle content and fat infiltration immediately around the knee (periarticular) associate with these knee OA outcomes. Thigh and calf muscle and fat infiltration quantified from magnetic resonance images were each related to knee pain and functional outcomes in non-overweight postmenopausal females (non-OW PMF). Greater fat infiltration and lower muscle content was generally associated with worse knee pain and function, with more significant associations observed for the calf. Thus, fat infiltration in periarticular muscles may be a risk factor for knee pain and worse function in non-OW PMF. Muscle and fat infiltration in different regions along the periarticular thigh and calf also had stronger associations with knee pain/worse function than in others, although future larger studies are needed to confirm these findings.
Glitches on the Gound: Investigating the Discursive Limits and Social Impacts of Uber’s Embedded Finance Experiments in Hyderabad, India
Keywords: debt
financialization
fintech
platform
welfare
work

In 2018, Uber launched three embedded finance experiments in India, Brazil, and Peru. Among these three sites, Uber Care in India was the most extensive and well-documented experiment, providing an extensive array of social and financial assistance programs. This research project investigates Uber Care as an effort to merge fintech schemes and corporate welfare for Uber’s workers through three empirical chapters: (1) a critical review of corporate documents that outline similar fintech integration into online gig work platforms; (2) a critical analysis of Uber Care’s promotional materials; and (3) a critical analysis of semi-structured interviews with ten labour organizers in Telangana state. I situate my findings within critical scholarship on two platform economies: gig work and fintech. I highlight the gulf between Uber’s claims about and labour organizer’s experiences with and observations of Uber Care, and I raise troubling questions about the ways in which these embedded finance experiments offer fintech firms opportunities to enclose precarious incomes, particularly in the context of digitally mediated gig work.
Counterfactual Explanations for Discrete Optimization
Keywords: Constraint Programming
Counterfactual Explanation
Discrete Optimization
Explainability
Mixed Integer Programming
Optimization

This thesis develops the first application of counterfactual explanations to optimal solutions of discrete optimization problems. The techniques studied respond to a contrastive question: why did the optimal solution did not satisfy a previously unstated specification? The explanations take the form of alternative objective parameters which would have resulted in the optimal solution satisfying the additional specification, while minimally perturbing the initial objective parameters. Such explanations are formalized as the Nearest Counterfactual Explanation (NCE) problem, which is based on a variant of inverse optimization. A novel cutting plane algorithm is developed to solve NCEs which explain problems with linear objectives and constraints. Two special cases of NCEs are also studied, based on restrictive question and answer forms.
Advancing Novel Methods for Interzonal Air Leakage Measurement in Multi-unit Residential Buildings
Keywords: Air Pressure
Airflow
Compartmentalization
Multi-Unit Residential Building
Sensor
Sound Transmission

Effective airflow control is an important aspect of building performance that contributes to ventilation energy efficiency, occupant comfort and safety. However, the lack of accessible interzonal airtightness measurement methods inhibits the implementation of meaningful compartmentalization standards in multi-unit residential buildings. The feasibility of two novel approaches were investigated. Using sound transmission loss as an indicator of air leakage rate across suite partition walls, the estimate accuracy of 0.59 L/s/m2 remains inadequate for compliance verification at 1.53 L/s/m2, but it could be a feasible approach for screening air leakage rates between similar partitions. Correlation models specific to typical wall assemblies could be developed in the future to improve this accuracy. When MEMS absolute pressure sensors were used to monitor air pressure differentials, after applying calibration and noise removal techniques, sensors with ±3 Pa rating produced pressure differential estimates of ≤10 Pa accuracy, which appeared adequate for selective operational airflow monitoring applications.
Closed-loop Control of Peripheral Nerve Stimulation using Resource-efficient Neural Networks
Keywords: closed-loop
functional electrical stimulation
neuroprosthetic
peripheral

Closed-loop control of functional electrical stimulation (FES) can restore movement to paralyzed limbs by using recorded nerve signals to modulate stimulation in real-time. Previous work performed state-of-the-art classification of nerve signals using neural networks (NNs). This thesis explored reduced NNs for use in implanted systems and incorporated such NNs into closed-loop stimulation. NNs of varying complexities were evaluated for performance and resource usage when classifying individual naturally-evoked compound action potentials, previously collected from rat sciatic nerves using 7x8-channel cuff electrodes. Acute in vivo experiments used NNs to estimate nerve branch activity in real-time as feedback for neural stimulation, producing desired ankle movement trajectories. Reduced NNs achieved macro F1-scores of 0.70-0.71 while remaining within resource constraints defined by NN implementations in integrated circuit fabrication technologies. We demonstrated closed-loop stimulation in 6 rats. NNs that classify nerve signals can be reduced to fit implantable hardware platforms and used for closed-loop stimulation control.
Acetylation as a Modifier of H2A.Z Function in Memory
Keywords: Acetylation
H2A.Z
Memory

DNA is packaged into the nucleus by wrapping around an octamer of histone proteins that form nucleosomes, which regulate DNA accessibility to transcriptional activators and repressors. Post-translational modifications (PTMs) of histone proteins are key regulators of transcription, with different PTMs producing unique effects on gene activity. Histone variants are a category of functionally unique histones that replace canonical histones in chromatin, yet PTMs are rarely considered in studies of histone variants. Our laboratory showed that the histone variant H2A.Z suppresses memory, but that its acetylation (H2A.Zac) is lastingly increased by learning, suggesting that H2A.Z may have a positive role in memory when it is acetylated. Indeed, acetylation of other histone types is positively linked with memory, which contrasts the suppressive effect of H2A.Z on memory when PTMs are not considered. Thus, the goal of my thesis was to investigate how acetylation alters the role of H2A.Z in memory. Rather than targeting acetylation writers and erasers using drugs, which influence modifications across different histone types, we selectively manipulated the acetylation profile of H2A.Z by overexpressing mutant constructs that either mimic or block H2A.Z acetylation. We found that H2A.Z acetylation has sex- and task-specific effects on memory; specifically, blocking H2A.Z acetylation in males significantly inhibits fear-memory without affecting object location memory. In females, mimicking H2A.Z acetylation enhances object location memory whereas blocking acetylation impairs this type of spatial memory, but neither manipulation impacted fear memory in female mice. This targeted gene-editing approach is a major leap in studies of histone PTMs in the brain as it provides the first direct investigation of acetylation’s function in H2A.Z-regulated memory and demonstrates H2A.Z’s unique sex-specific effects on aversive and non-aversive memories.
SilverFace: Automated Authentication of Older Adults using Face Recognition
Keywords: Automated Authentication
Face detection
Face identification
Face Recognition
Older Adults

Recent interest in exergaming, and ambient activity technologies in long term care, is creating a need for better methods of authenticating older people that do not require things to be remembered (passwords) or objects to be carried around (e.g., badges and RFID tags). Face recognition is a promising form of automated authentication that doesn’t require any effort or input on the part of the users. Using existing deep learning algorithms, with data trained on older faces, two face recognition authentication prototypes were developed on inexpensive single board computers running a customized Ubuntu version of Linux. The second prototype ("SilverFace") used a more powerful computer that avoided overheating problems found with the first prototype. SilverFace was integrated with the 2RaceWithMe exergaming system installed at the York Care Centre long term care home in Fredericton. Results from the York Care Centre trial, and from an evaluation by Ambient Activity Technology (AAT) are reported.
Homomorphically Trained Neural Networks
Keywords: Autograd
Automatic differentiation
Homomorphic encryption
Machine learning
Optimization

This thesis has two main contributions. Firstly, we present Cryptograd: an autograd-compatible homomorphically encrypted training and inference library built in Python. Using this library, we successfully train a fully encrypted model using fully encrypted training data on the QSAR Andogen receptor dataset. We obtain an accuracy value of 90% and a total training time of 670s on an Intel Core i7-11700K @ 3.60GHz using 12 cores. Secondly, we introduce a modified privacy-preserving federated learning scheme. At the core of this scheme is DRMSprop: a decentralized optimizer that utilizes a global gradient vector to improve convergence, stability, and performance. This modified scheme yielded an accuracy increase of 1.7% relative to other optimizers on the census income prediction dataset. Furthermore, it lags behind the optimal insecure model by only 2.3%.
Long-term Stiffness and Shrinkage Strain Monitoring of Reinforced Concrete Elements
Keywords: Concrete
Elastic
Monitoring
Shrinkage
Stiffness
Strain

It is important to accurately evaluate the initial uncracked stiffness in critical buildings such as nuclear power plants to determine their serviceability, natural periods, and dynamic response. Based on a literature review, the initial stiffnesses of RC elements are less than the stiffnesses estimated from plain concrete properties. This one-year experimental program showed that the initial compressive stiffnesses of plain and reinforced normal strength concrete decreases over time in an indoor environment. Based on the reduction rate correlation with reinforcement ratio and drying age, it is necessary to further investigate the stiffness trends regarding the shrinkage to draw a general conclusion. In addition to the topic, a new strain gauge and shrinkage monitoring system are proposed and tested for future large-scale and long-term deployments. The results from thermal characteristics, gauge factors, and the average measurement across concrete cracks proved the potential of the system and the validity of testing methodologies.
Multilayer C3N/Blue Phosphorene Heterostructures as Effective Anode Materials for Potassium-ion Batteries
Keywords: electric vehicles
multilayer heterostructures
potassium-ion batteries
theoretical capacity

Two-dimensional van der Waals heterostructures outperform conventional anode materials for post-lithium ion batteries in terms of mechanical, thermal, electrical, and electrochemical properties. This study systematically investigates the performance of multilayer C3N/Blue Phosphorene (C3N/BP) heterostructures as anode materials for potassium-ion batteries (KIBs) using first-principles density functional theory (DFT) simulations. We demonstrate that the electronic, mechanical, and electrochemical properties of multilayer C3N/BP heterostructures are markedly superior to those of their monolayer counterparts. Most prominently, a two-layer heterostructure (C3N/BP) effectively reduces the bandgap of the BP monolayer (1.98 eV) to 0.02 eV, whereas three-layer heterostructures (bilayer-C3N/BP and C3N/bilayer-BP) exhibit metallic behavior with no bandgap. Additionally, the theoretical capacity of the proposed heterostructures ranges from 636.7 mAh.g-1 to 755.5 mAh.g-1, considerably higher than the theoretical capacity of other 2D heterostructures for KIBs, ranging from 209.8 mAh.g-1 to 727.6 mAh.g-1. Overall, our findings indicate that C3N/BP heterostructures can function as high-performance anode materials for KIBs.
Identifying the Hematopoietic Cells Immortalized by HOXB4
Keywords: Cytometry
Hematopoiesis
HOXB4
Mice
Self-renewal
Stem cell

Self-renewal is the ability of a cell to produce identical daughter cells upon division. Multipotent hematopoietic stem cells (HSCs) permanently self-renew whereas more differentiated cells have only transient self-renewal capacities or none at all. Despite the importance of self- renewal in sustaining blood cell populations, the molecular mechanisms that regulate it is unclear. Hoxb4, a member of the Homeobox family of transcription factors, has been implicated in self-renewal regulation due to evidence suggesting that exogenous HOXB4 seems to sustain the self-renewal capacity of oligopotent progenitors (OPPs). However, the specific cells susceptible to this immortalization remains unknown. The purpose of my thesis is to identify these cells so that they can be purified and analyzed which will uncover the regulatory underpinnings of self- renewal. I have identified a potential cell population that exhibits permanent self-renewal given HOXB4. These cells are not as primitive as multipotent HSCs nor as differentiated as certain OPP subsets.
Supervised and Unsupervised Deep Learning Seizure Prediction using EEG
Keywords: Anomaly detection
Autoencoder
EEG
Epilepsy
Seizure prediction
Unsupervised learning

Epilepsy affects more than 50 million people worldwide, making it one of the world’s most prevalent neurological diseases. The main symptom of epilepsy is seizures, which occur abruptly and can cause serious injury or death. The ability to predict the occurrence of an epileptic seizure could alleviate many risks and stresses people with epilepsy face. We have taken several approaches to predict the occurrence of a seizure using deep learning. Firstly, we developed a supervised model to identify pre-seizure EEG from normal EEG. Then, we developed an unsupervised approach where the model is trained on just the normal EEG, and pre-seizure EEG is identified as an anomalous event indicating the onset of a seizure. These models were trained and evaluated on two public EEG databases. We have found that both supervised and unsupervised approaches are feasible; however, their performance varies depending on the patient and the approach and architecture.
Design and Evaluation of a Hand Hygiene Prompting System for Private Residences
Keywords: biometrics
Hand hygiene
infection control
prompting
smart home

Hand hygiene can prevent the spread of infection, but it is often overlooked in the community. The objective of this project was to develop and evaluate a hand hygiene prompting system for use at the entrance of private residences. The system included passive infrared sensors, a buzzer, and a light emitting diode connected to a microcontroller that was programed to prompt individuals to wash their hands using an attached alcohol gel dispenser as they entered their residences. The system was evaluated over 4 weeks in 20 households (10 control and 10 intervention). There was an increase in hand hygiene adherence (41.7% to 92.5%, p < 0.0001) for the intervention group in Week 2 when prompting was activated, followed by a decrease in Week 3 after prompting was deactivated (92.5% to 44.8%, p < 0.0001) while no change was seen for the control group (p = 0.789). Key words: Hand hygiene, prompting, infection control, smart home, biometrics
Examination of Mitochondrial Genetic Variation in Reported Autism Spectrum Disorder
Keywords: Admixture
Autism Spectrum Disorder
Genetics
Mitochondria
Mitochondrial DNA

The knowledge surrounding the neurobiology of Autism Spectrum Disorder (ASD) remains limited. Mitochondrial dysfunction appears to be involved in the etiology of ASD, given evidence indicating disrupted oxidative phosphorylation and increased oxidative stress in ASD. Therefore, variation within mitochondrial genes may contribute to ASD. The objective of this study is to examine whether mitochondrial genetic variation is associated with ASD risk. N = 172 reported autism cases and 9854 controls ages 9-10 from the Adolescent Brain Cognitive Development (ABCD) study were selected for analysis. Tractor software was used to conduct an ancestry-aware logistic regression for reported autism diagnosis and nuclear-encoded mitochondrial SNPs. Next, a meta-analysis using the ABCD European sub-sample, and the Psychiatric Genetics Consortium ASD sample was conducted using METAL. Finally, mtDNA haplogroups were analyzed for association with reported ASD diagnosis using the Chi-squared test. No nuclear-encoded mitochondrial SNPs or mtDNA haplogroups were significantly associated with reported ASD diagnosis.
Labour Supply Outcomes of Informal Home-based Palliative Caregivers
Keywords: Health Economics
Informal labour
Palliative care

Introduction: Informal palliative caregivers provide ongoing care and support to patients and are at increased risk to reduce their labour supply and to modify their labour market behaviours. Objective: The purpose of this thesis was to assess the relationship between the supply of informal palliative caregiving and labour supply outcomes over the care trajectory. Methods: This study used prospective longitudinal cohort data of palliative care caregivers in Ontario from 2014-2017 obtained through interviews with informal caregivers. Regression models were used to estimate the effects of informal caregiving on labour supply outcomes. Results: There is a negative association between informal palliative caregiving and labour supply intensity and propensity. Caregivers providing more than 58 hours of care bi-weekly experienced the steepest decline in labour force participation. Conclusion: Support and workplace legislation that encourages flexibility for caregiving-labour arrangements may improve economic outcomes for families and employers.
Exploring the Possibilities of Settler Filipino Food Sovereignty in Toronto: Theory, Filipino Farmers, and Accountability to Indigenous Sovereignty
Keywords: Filipino-Indigenous solidarities
food sovereignty
food systems learning
land relationality
Toronto
urban farming

This thesis aims to understand the possibilities of settler Filipino food sovereignty in right relation to Indigenous sovereignty in Toronto. On the surface, food sovereignty for a settler community seems incompatible with Indigenous sovereignty due to on-going settler colonialism. Through interviews with six Toronto-based Filipino farmers, literature and personal experience, this thesis highlights how farming, gardening, seed keeping, and food sovereignty activities is as a portal of relationship building with Indigenous Peoples and with the land as diasporic people. Further, through farming, farmers are preserving and promoting Philippine foodways amongst their communities in Toronto, and with this tangible land-based work invokes transformative responsibilities that ultimately challenge ongoing-settler colonialist paradigms in Toronto and surrounding areas. This thesis thus, positions growing food and land relationality as a crucial tool in Indigenous-Filipino relationship building and in building decolonial food systems.
Sex Differences and Predictors of Post-stroke Depressive Symptoms and Achieving Recommended Physical Activity Target Levels
Keywords: Physical activity
Post-stroke depression
Rehabilitation
Sex difference
Stroke

Post-stroke depressive symptoms (PSDS) and low physical activity (PA) levels are common sequelae of stroke, with some evidence that PSDS influences PA. Yet, there is limited research on sex differences and sex-specific predictors of these stroke sequelae. The objectives were to determine sex differences and predictors of PSDS at entry to cardiovascular rehabilitation (CR) through a retrospective database analysis and develop a study protocol of sex differences and predictors of achieving PA recommendations post-stroke. Studies included multivariate analyses to determine predictors in all patients, and women and men separately. Retrospective study findings revealed women were disproportionately affected by PSDS in bivariate and multivariate analyses, indicating timely screening and management of PSDS is needed, especially for women. There were mostly unique predictors of PSDS between women and men, indicating tailored interventions are needed. Lower cardiorespiratory fitness (V̇O2peak) predicted PSDS, indicating sex differences and predictors of PSDS may influence achieving PA recommendations.
Representation Theorems for Mereologies
Keywords: graph
mereology
partial ordering
representation theorem
simplicial complex
strong supplementation principle

In non-classical mereologies, not every pair of underlapping elements has a sum. Hence, it begs the question as to what types of elements have sums, as well as its relationship to mereologies. Beyond intrinsic academic value, these questions are also of pragmatic interest - previous works have shown that non-classical mereologies are essential and not just optimal for the representation of gene sequences, time intervals, and machine scheduling plans. The goal of this thesis is hence to provide a new representation theorem for extensional and classical extensional mereology, for the purposes of clarifying the relationship between classical and non-classical mereologies. We provide a total of 5 representation theorems, utilizing algebra, set theory and graph theory for finite models of extensional mereology and classical extensional mereology, as well as a conjecture to guide future work in infinite models of classical extensional mereology.
A Qualitative Study to Understand the Lived Experience of Socially Frail Older Adults
Keywords: aging
older adults
qualitative study
social frailty

Background: Social frailty is an important public health priority among older adults, but its risks and challenges are not well understood. This study sought to understand the lived experience of socially frail older adults. Methods: A qualitative description study was conducted with 17 socially frail or at-risk older adults. A “Life Map” approach that considers six areas of a person’s life was used to explore the social frailty experience. Thematic analysis (qualitative data) and descriptive statistics (quantitative data) were performed. Results: Participants perceived their lived experience of social frailty as: (1) a life event that triggered their social frailty state, (2) leading to consequences and challenges, which (3) prompted the use of a range of coping strategies and supports to overcome challenges. Conclusion: This study contributes to the understanding of how older adults experience social frailty. Results can be used to create an intervention to reduce, prevent, or reverse social frailty.