VictorJuiz/thesis huggingface dataset:
Supporting Healthcare Worker Mental Health during the COVID-19 Pandemic: Learning from Peer Support Facilitators

Healthcare Workers are at risk of long-term negative mental health effects resulting from the COVID-19 pandemic. The Social Support, Tracking Distress, Education and Discussion Community Staff Wellness Program was implemented in select hospital units during the pandemic. Programming was facilitated by multidisciplinary peer supporters; this project aimed to elucidate their experiences, and gain insight into lessons learned and future directions for the implementation of peer support programming. Two open-ended, semi-structured focus groups were conducted with peer supporters. Transcripts were inductively and iteratively read and coded. Codes were deductively categorized to summarize relevant information. Peer supporters described benefits and challenges of the role, reporting an overall positive experience. Building trust with the target group was highlighted as important to program uptake. When planning similar work, groups should aim to build organizational, as well as individual, resilience by targeting leadership and incorporating non-pathologizing messages regarding wellness in onboarding and routine team meetings.

Keywords: healthcare worker
mental wellbeing
occupational stress
Advisor: Maunder, Robert
Investigation of Soft Tissue Healing around Osseointegrated Titanium Mini-implants Placed in the Mandibular Diastema of Rabbits

A novel rabbit mandibular diastema model was employed to investigate the soft tissue-implant interface of various implant surface topographies. A total of 96 custom designed titanium implants were placed in the mandibular diastemas of 24 sixteen-week-old New Zealand white rabbits. Four different surfaces were examined: (1) machined (2) machined surface, roughened through anodization; (3) dual acid-etched; and (4) dual acid-etched with anodization. After 7, 21, and 42 days, the soft tissue-implant interface was examined by both light and scanning electron microscopy (SEM). While no significant differences were observed in collagen fibre orientation and fibrous tissue thickness by polarized light microscopy, SEM images showed that topographically complex surfaces had a profound effect on soft tissue peri-implant entanglement. Increasing implant surface topographic complexity increased both the amount and structural organization of peri-implant soft tissue. The rabbit diastema also provides advantages from practical, economic, and ethical points-of-view over more traditional implant placement sites.

Advisor: Davies, John JD
Measuring Abdominal Pain in Irritable Bowel Syndrome: Scoping Review and Preliminary Results of a Validation Study

Abdominal pain in irritable bowel syndrome (IBS) is multi-dimensional and often interferes with daily function in IBS patients. The aims of this thesis are: 1) to review the literature regarding instruments to measure abdominal pain in IBS; and 2) to present the preliminary results of a validation study examining the measurement properties of an adapted version of the Brief Pain Inventory (BPI) to measure abdominal pain in IBS. Based on a scoping review, we confirmed a lack of evidence of validity of a multi-dimensional instrument to measure abdominal pain in IBS. A preliminary analysis of the first 14 participants in a cohort validation study of the adapted BPI was performed demonstrating that the adapted BPI may offer a reliable and valid measure of abdominal pain that measures both pain intensity and pain interference. These results may have an impact on patient care and the conduct of clinical trials of novel IBS therapies.

Keywords: Abdominal pain
Irritable bowel syndrome
Measurement
Reliability
Scoping review
Validity
Advisor: Tinmouth, Jill
A Spatial Analysis of Overdose Mortality Incidence and Supervised Consumption Services in Toronto, Canada

It is well-established that supervised consumption services (SCS) prevent overdose deaths on site, but evidence gaps remain regarding their capacity to impact overdose mortality at the population level. This study sought to characterize overdose mortality in Toronto, Canada, a city with heightened overdose incidence, and investigate the association between SCS proximity and overdose mortality incidence. First, overdose mortality incidence rates were compared before and after the implementation of nine SCS. Second, overdose incident data were assessed for global spatial autocorrelation and local clustering (i.e., hot spots). Third, geographically-weighted regression was employed to model the association between SCS proximity and overdose mortality incidence. Findings revealed that (1) overdose deaths in SCS- surrounding neighbourhoods decreased significantly post-implementation; (2) overdose deaths were significantly spatially autocorrelated and the magnitude of local clustering decreased in SCS-surrounding neighbourhoods year-over-year; and (3) the spatially-mediated impact of SCS on overdose mortality incidence increased in both magnitude and area year-over-year.

Keywords: drug policy
harm reduction
injection drug use
opioid overdose
spatial analysis
supervised injection site
Advisor: Werb, Dan
Identifying Endocrine-disrupting Chemicals Binding to Human Nuclear Receptor and Intracellular Lipid-binding Proteins

Endocrine-disrupting chemicals (EDCs) mimic the functions of endogenous hormones to modulate endocrine systems that can cause adverse health effects. Most EDCs remain unidentified due to the immense number of chemicals in commerce. This thesis focused on identifying EDCs binding to the fatty acid binding proteins (FABPs) and human estrogen related receptor gamma (ERRg). The first project demonstrated that the minor structural changes of PFECAs from legacy PFAS show broad-spectrum binding activity to target human proteins. In the second project, I developed a protein affinity purification method to identify EDCs at the exposome-wide level to discover the hitherto unknown compound, nitrate bisphenol A (NO2-BPA), that binds to the ERRg. NO2-BPA was found to be transformed from bisphenol A through heterogeneous HONO reactions in the indoor environment. This finding has expanded knowledge of a large class of nitration compounds formed via reactions with HONO.

Keywords: BPA
Endocrine-disrupting chemicals
Estrogen related receptor gamma
Fatty acid binding proteins
HONO
PFECA
Advisor: Diamond, Miriam
Peng, Hui
Source Apportionment of Volatile Organic Compounds in the Athabasca Oil Sands Region

Emissions of volatile organic compounds (VOCs) from oil sands operations in the Athabasca region of Alberta are known to impact Fort McKay (a nearby Indigenous community), often causing poor odours. However, the relative contribution of specific sources to the VOCs observed in Fort McKay has remained unclear. To address this, community exposure to non-methane hydrocarbons (NMHCs) was attributed to nearby sources through two independent approaches; a chemical mass balance (CMB) model which relied on speciated VOC measurements to be used as chemical tracers, and a surface level trajectory model using wind measurements from several nearby stations. The results showed that the two major facilities south of Fort McKay, operated by Suncor and Syncrude, accounted for 40 – 42 % of total observed exposure, while the two nearby Canadian Natural Resources Limited (CNRL) operations (Horizon and Jackpine/Muskeg River) accounted for 13% – 14% of total observed exposure.

Keywords: back-trajectory
chemical mass balance
non-methane hydrocarbons
oil sands
volatile organic compounds
Advisor: Evans, Greg J.
Brook, Jeffrey R.
Centre-based Childcare in Early Childhood and Adiposity in Later Childhood

Attending centre-based childcare in early childhood may influence the development of important health behaviours including dietary intake, eating behaviour, physical activity, and routines but its impact on childhood adiposity and weight status is unclear. In this thesis, I have evaluated the relationship between centre-based childcare attendance (hours/week) in early childhood (1 – 4 years of age) and body mass index z-score (zBMI) in later childhood (4 – 10 years of age) compared to non-centre-based childcare. Through a prospective cohort study of healthy children participating in the TARGet Kids! cohort, attending centre-based childcare in early childhood was associated with a lower zBMI and lower odds of overweight and obesity in later childhood compared to non-centre-based childcare. These associations were stronger for children from lower income families. These findings suggest that attending centre-based childcare in early childhood may be an effective early intervention for the prevention of childhood obesity.

Advisor: Maguire, Jonathon
Examining The Influence of The Self-referential Bias on Aberrant Salience and Jumping to Conclusions Bias in Individuals with Schizophrenia-Spectrum Disorders

Neurobiological and cognitive processes such as aberrant salience (AS) and the jumping to conclusions (JTC) bias are implicated in the development of delusions. Self-referential thinking (SRT) has also been implicated in this process, however, no research has examined how SRT may interact with AS and JTC in individuals with schizophrenia-spectrum disorders (SSDs). The present study examined whether manipulating SRT led to an increase in AS and JTC in individuals with SSDs (n= 20) relative to psychiatrically healthy controls (n= 20), and if greater levels of SRT moderate the relationship between AS, JTC, and delusion severity. Overall, SRT did not influence levels of AS or JTC bias and did not significantly interact with either AS or JTC bias to predict delusion severity. These results indicate that while SRT is related to delusion severity, AS, and JTC bias, it may not interact with these processes to promote the development of delusions.

Keywords: Cognitive Bias
Delusions
Schizophrenia
Advisor: Best, Michael W
Predicting Duration of Surgery to Schedule Elective Orthopaedic Surgery

Objectives:The aim of this thesis was to determine if a two-stage approach utilizing a machine learning (ML) model for prediction of duration of surgery (DOS) paired with schedule optimization improves operating room over/underutilization compared to using the mean duration. Materials and Methods: ML models were compared to determine the best model for predicting DOS and length of stay (LOS) using patient factors. DOS predictions were used as an input to three schedule optimization formulations, which were evaluated using the true labels. Results: Neural networks performed best in predicting DOS and LOS based on mean squared error. The Split and MSSP formulations yielded similar results and performed significantly better than the Any formulation. The schedules that utilized ML-predicted DOS outperformed the mean surgery duration over all schedule hyperparameters, with an average overtime reduction of 300-500 minutes/week. Conclusion: Optimizing surgical scheduling using a predict-then-optimize approach improves operating room efficiency.

Advisor: Khalil, Elias B
A Journey towards Allyship: How Middle-class, Second Generation South Asian Canadian Mothers Challenge Anti-black Racism

This study explores how self-identified middle-class second generation South Asian Canadian mothers journey towards allyship with racialized Black people in dismantling anti-Black racism. Using Participatory Action Research principles, as well as Critical Race Theory and Intersectionality Theory as frameworks, three key findings emerged from the data. First, the journey towards allyship begins with envisioning ourselves as racial justice allies and determining what that means to us, doing the introspection work to examine our own internalised racism, and then working to unlearn those perspectives. The journey towards allyship moves forward by acknowledging our capability to address anti-Blackness in our familial and social networks as well as in institutions such as schools and workplaces. And, the journey towards allyship is sustained by the support of middle-class, second generation South Asian Canadian mothers with similar anti-racism goals sharing resources and stories of their journeys thereby catalysing new understandings of privilege and oppression together. These findings are a meaningful contribution to larger scale efforts in addressing anti-Black racism and achieving social justice for racialized Black people. They are also a contribution to the growing body of research on middle-class second generation South Asian Canadians and, a source of inspiration for us as individuals and as a supportive community of mothers to continue our journey as aspiring allies of colour beyond the scope of this project.

Keywords: Allyship
Anti-Racism
Critical Race Theory
Intersectionality Theory
Second Generation Canadians
South Asian Studies
Advisor: Mirchandani, Kiran
Investigating the Endocannabinoid System in Major Depressive Episodes: Imaging with the Radiotracer [11C]CURB

Purpose. To determine whether brain fatty acid amide hydrolase (FAAH) is elevated in vivo in patients with major depressive episodes (MDE) and if FAAH is related to depressive severity.Methods. Medication-free MDE and healthy control (HC) participants were recruited. All participants were administered the Structured Clinical Interview for DSM-5 and Hamilton Depression Rating Scale. FAAH was measured using [11C]CURB positron emission tomography. Results. Seven MDE and 10 age- and sex-matched HC participants completed the study. Data showed no significant group differences in FAAH, and no correlation between FAAH and depressive severity in MDE. FAAH in the medial prefrontal cortex, amygdala, ventral striatum, and substantia nigra were positively correlated with apathy in MDE. It should be noted that this study was underpowered. Conclusion. This study is the first to investigate FAAH in MDE in vivo. Despite no significant group differences in FAAH levels, FAAH may be related to apathy in MDE.

Keywords: depression
endocannabinoids
neuroimaging
Advisor: Kolla, Nathan J
The Relationship between Large-scale Atmospheric Oscillations and Cyclone Patterns, and Their Impacts on Summer Precipitation Distribution in the Canadian Arctic

A trend analysis of the Arctic System Reanalysis Version 2 (ASRv2) data from 2000 to 2015 showed that changes occurring with summer rainfall and snowfall are synchronized in the Canadian Arctic. The precipitation distribution in the Canadian Arctic with the low-pressure system (center pressure < 1000hPa) patterns showed high consistency; however, snowfall in areas including Ellesmere Island and northeastern mainland NU was not found to be related to the cyclone distribution. The influences of the summer Arctic Oscillation (AO) and North Atlantic Oscillation (NAO) on the cyclones vary regionally, leading to a complicated distribution pattern of rainfall and snowfall. These variations might also be related to sea ice opening and local evaporation, in addition to the moving jet stream. Under the circumstances of global warming and Arctic amplification, changes in summer precipitation might have substantial impacts on the hydrology, sea ice, and permafrost conditions in the Canadian Arctic.

Keywords: Canadian Arctic
Cyclones
Large-scale oscillations
Precipitation
Trends
Advisor: Brown, Laura C
Time Series Classification and Augmentation with Domain-agnostic Self-supervised Learning for Combustion Signature Analysis

When responding to freight transportation fire incidents with unknown or mixed materials, first responders require decision support on the appropriate emergency response strategy. In this work, we propose to use machine learning (ML) to aid first responders by identifying hazard characteristics (e.g., toxicity and explosivity) of a given fire using the time series profile of chemicals found in the effluent. We experiment with time series classification algorithms, enhance their performance with time series augmentation techniques, and demonstrate that a model named MultiRocket achieved high testing performance with minimal inference time. Additionally, we explore using self-supervised learning to learn patterns of the data without the need of any handcrafted augmentations and demonstrate that it is a promising alternative avenue to training supervised ML models. Our proposed toolkit benefiting from machine learning will pave the way for further research in accessible, easily-deployable AI-enabled tools in fire sciences and management.

Keywords: Self-Supervised Learning
Time Series Augmentation
Time Series Classification
Advisor: Lee, Chi-Guhn
The Bacterial Microbiome of Four Hard Red Spring Wheat (Triticum aestivum) Cultivars in the Context of Fusarium Head Blight

Fusarium head blight (FHB) is a serious disease in wheat and other cereal grains, caused by several Fusarium species including Fusarium graminearum. The mycotoxins secreted by these fungal pathogens can be lethal if ingested in large quantities, and their accumulation in cereals results in significant annual crop losses worldwide. Current disease management strategies are struggling to cope with FHB outbreaks and could be improved via the identification and utilization of bacterial endophytes that provide their hosts with disease suppression against FHB. The aim of this project was to identify native bacterial endophytes in the wheat heads of four cultivars of Canadian hard red spring wheat of varying FHB resistance, to investigate any links between microbiome profile and host resistance level. DNA sequencing of the bacterial 16S rRNA gene revealed significant differences in species prevalence and abundance among cultivars and among samples collected at early and late stages of FHB infection.

Keywords: 16S
bacteria
DNA sequencing
Fusarium
microbiome
wheat
Advisor: Guttman, David S
The Adoption, Use, and Impacts of Ride-sourcing Services in the Metro Vancouver Area

The advent of a new travel mode can transform travel behaviour and urban transportation systems. While ride-sourcing services provided by Transportation Network Companies have generally been established in most urban areas, they only recently became available in Metro Vancouver, Canada. Given the relative novelty of ride-sourcing in the region, it is important to understand the impacts of its introduction. This thesis aims to examine the factors influencing the adoption and use of ride-sourcing services and the impacts of said services on the use of other modes in Metro Vancouver through a web-based survey administered to residents of the region. Additionally, this thesis presents the results of empirical work performed using the collected survey data. The results can help planners understand the role that ride-sourcing plays and its relationship with other travel modes. The results can also be used to develop policies that harness the benefits of ride-sourcing.

Keywords: Mode choice
Ridehailing
Ridesourcing
Stated preference
Transportation network company
Uber
Advisor: Nurul Habib, Khandker KNH
Ab Initio DFT Approaches to CMOS Quantum Dot Simulation

An ab initio, atomistic, density functional theory (DFT) simulation approach is reported to capture the impact of temperature, gate oxide spacer width, gate length, and device dimensions on the Coulomb peaks in the drain current characteristics of Si n-type nanowire single electron transistors (SETs). The Coulomb peaks are observed at temperatures as high as 50 K. The tunneling drain current peaks and the peak-to-valley drain current ratios show exponential dependencies on device dimensions, while variations in the scaled nanowire radius result in radically different Coulomb signatures. Variations in gate length highlight the effects of scaling on device capacitance. These findings have important implications for the fabrication process control of current and future generations of quantum devices.

Keywords: CMOS
DFT
Nanowire
Quantum computing
Quantum dots
resonant tunneling
Advisor: Voinigescu, Sorin
Design of a Custom Rideshare Payload Adapter for the GHGSAT-C3/C4/C5 Microsatellites Launched in Tandem

The increasing repercussions of climate change have encouraged governments and corporations to adopt better ways to monitor and quantify greenhouse gas emissions, opening new opportunities in space-based Earth monitoring. The rapid advancement in space technology has increased small satellite missions dedicated for Earth observation. The Space Flight Laboratory has been developing microsatellites for GHGSat Inc. which is becoming the global reference for remote sensing of greenhouse gas from any source in the world. This thesis presents the complete design cycle of a custom Rideshare payload adapter for a cluster of three microsatellites. Finite element analysis is presented to verify the adapter’s compliance with all structural requirements. Necessary ground support equipment is designed to ensure appropriate handling of the structure. The adapter is then qualified for launch through vibration testing. Experimental data is analyzed to update the simulation models and to develop appropriate testing profiles for spacecraft qualification.

Keywords: Falcon 9
GHGSat-C3/C4/C5
Launch Adapter
Microsatellites
Rideshare Launch
Space Systems
Advisor: Zee, Robert E.
Effectiveness and Cost-effectiveness of Vehicle Lifespan Caps for Reducing Light-duty Vehicle Fleet GHG Emissions in the U.S.

Accelerated vehicle turnover gets new technologies on the road faster but increases the rate of vehicle production and purchases. By combining vehicle fleet modelling, life cycle assessment (LCA), and total ownership costing this work estimates the GHG emissions and costs for the U.S. light-duty vehicle fleet from 2020 – 2050 under a forced early retirement program. We estimate that under current EV sales projections, even when combined with vehicle light-weighting, fuel consumption improvement, and vehicle size reduction, vehicle lifespan caps are ineffective at reducing GHG emissions. While under a 100% EV sales target by 2035, applying a 12-year lifespan cap on conventional light-duty vehicles can be effective, reducing cumulative GHG emissions from 2020 through 2050 by 6%. However, the abatement costs for this method are high, near 2020 USD 1000/tCO2e, placing either a high burden on the government for providing incentives or markedly increasing average vehicle ownership costs.

Keywords: carbon emissions
electric vehicle deplyoment
life cycle assessment
light-duty vehicles
vehicle turnover
Advisor: MacLean, Heather L.
Advancing the Development of a Maritime Monitoring Satellite from Design to Payload Testing

The newest maritime monitoring satellite for Norway is NorSat-4, whose purpose is to improve situational awareness in Norwegian territorial waters. The mission is housed within a Space Flight Laboratory designed satellite bus, and utilizes the Automatic Identification System receiver and Low Light Imager payloads to meet its objectives. Contributions to advancing the completion state of the mission in this thesis fall under the Command \& Data Handling and Payload subsystems, as well as Assembly, Integration, \& Testing. Of these contributions, a software program is presented that can control the Low Light Imager and save pictures to file. Designs for physical systems have been created as well, including the satellite wire harness and flatsat. Finally, the flatsat wireless communications were set up in preparation for payload testing. Through rigorous testing, following best practices, and meeting mission requirements, these contributions will play a part in ensuring the mission’s successful completion.

Keywords: NorSat-4
Satellite
Spacecraft
Advisor: Zee, Robert E