VictorJuiz/thesis huggingface dataset:
The Fate of Isocyanic Acid (HNCO): Investigation into Aqueous Phase Chemistry of HNCO

Isocyanic acid (HNCO) is an organic acid pollutant emitted by various sources, including: biomass burning, coal combustion, vehicle exhaust from gasoline and diesel engines, cigarettes from pyrolysis of urea and oxidation of nicotine, and produced via photochemical reactions of amines and amides in the atmosphere. Because of slow gas phase losses, the predominant removal of HNCO from the atmosphere is thought to be through dry deposition and heterogeneous uptake and subsequent hydrolysis. This thesis explores the overall hydrolysis (combination of three reactions with rate constants k1, k2, and k3) of HNCO, khyd, and has re-evaluated its associated rate constants, k1 and k2, for atmospherically relevant temperatures and pH values. The Arrhenius equation for k2 was determined to be k2 = (2.4 ± 5.9) x 1010 exp(-9126 ± 695/T) s-1 but, more data was needed to confidently calculate k1. Additionally, the partitioning characteristics of HNCO in aqueous droplets were investigated through simulated evaporation events.

Keywords: Chemistry
Advisor: Murphy, Jennifer G
A Computational Model of Seizure Termination and Postictal Generalized EEG Suppression

Understanding seizure termination is clinically relevant as it is sometimes followed by the postictal generalized EEG suppression state (PGES), which is a period with suppressed activities and has been found to be associated with sudden unexpected death in epilepsy. This work aims to investigate the hypothesis that the balance of excitation and inhibition (E/I balance) in pathological brain network plays an important role in the dynamics of seizure and PGES. A network of 1000 Izhikevich model neurons was developed, and simulation results were compared with recordings from human epileptic patients. Reduced dominant frequency rise and decay rate before seizure termination and suppression in activity following termination were observed in iEEG recordings of seizures followed by PGES. Those characteristics were reproduced in the simulated local field potential by changing the E/I balance of the model network. Those results highlight the importance of E/I balance in the dynamics of seizure and PGES.

Keywords: Computational Modeling
E/I Balance
Epilepsy
iEEG
Postictal Generalized EEG Suppression
Time-Frequency Analysis
Advisor: Bardakjian, Berj
Effect of Clear Aligner Therapy on Jaw Motor Function

Recent evidence indicates that clear aligner therapy (CAT) induces mild to moderate tooth and jaw muscle pain. This study aimed to measure the effect of CAT on the electromyographic (EMG) activity of the masseter. It was hypothesized that CAT induces an increase in the EMG activity of the masseter during day-time. The EMG activity of the masseter was recorded in 17 adults over 4 weeks (baseline – no aligners; a passive aligner not moving teeth; first active aligner; and second active aligner) using portable devices. CAT induced a significant increase in masseter activity (all p

Keywords: Clear Aligner Therapy
Dentistry
Electromyography
EMG
Jaw Motor Function
Orthodontics
Advisor: Cioffi, Iacopo
Textbook Outcomes in Gastric Cancer Surgery

Textbook Outcomes, a composite of eight perioperative metrics, represent a comprehensive surgical quality measure in gastric cancer surgery. The objectives of this thesis were to determine the long-term survival implications of achieving Textbook Outcomes and to estimate the association between gastric cancer surgery case-volume and Textbook Outcomes. A population-based cohort study of patients with non-metastatic gastric adenocarcinoma treated with curative gastrectomy between 2004 and 2015 was conducted. Multivariable regressions analyses were conducted in order to estimate the association between (i) Textbook Outcomes and survival and (ii) gastrectomy volume and Textbook Outcomes. Textbook Outcomes were achieved in merely 23% of the cohort and were associated with a 39% reduction in mortality (aHR 0.61 [95%CI 0.50, 0.74], p

Keywords: Gastrectomy
Population
Quality
Stomach Cancer
Surgery
Textbook
Advisor: Coburn, Natalie
Assessing the Feasibility of High-intensity Interval Exercise in Patients with Peripheral Artery Disease

Peripheral artery disease (PAD) is associated with diminished functional capacity. Exercise is an effective therapy, but adherence to traditional exercise is not ideal. High-intensity interval exercise (HIIE) results in greater improvements to aerobic capacity compared to moderate-intensity continuous exercise. The objective of the study is to assess the feasibility of HIIE for patients with PAD, and explore its physiological, subjective and psychological responses. Participants performed: 1) traditional exercise (moderate-intensity walking); and 2) HIIE. Oxygen consumption, heart rate, muscle oxygen saturation and pain were assessed. Participants completed questionnaires to assess psychological responses. HIIE was feasible and safe for patients with PAD. Lower levels of pain were experienced during HIIE and all participants preferred the HIIE. HIIE may be an alternative to traditional walking and should be considered. The potential physiological and psychological advantages warrant further exploration. Reducing pain during exercise may be important to maximizing the chances for patients to succeed.

Keywords: exercise
high-intensity interval
intermittent claudication
peripheral artery disease
Advisor: Thomas, Scott G
Effects of Human Umbilical Cord Perivascular Cell-conditioned Media in Adult Zebrafish Model of Traumatic Brain Injury

The pathophysiological events of secondary brain injury contribute to the consequences of traumatic brain injury. The neuroprotective effect of mesenchymal cells has been extensively studied and evidence suggests that their effects are mostly mediated through their secretome. The secretome of human umbilical cord perivascular cells can potentially attenuate the downstream pathways associated with secondary brain injury. I hypothesized that conditioned media containing secretome of human umbilical cord perivascular cells can improve outcome after modelled traumatic brain injury. I demonstrated that the human umbilical cord perivascular cell-conditioned media can reduce GFAP expression and TUNEL+ cells in the brain 24-hours after modelled traumatic brain injury. Furthermore, improvements in locomotor activity and anxiety were also observed at 6- and 24-hours after modelled traumatic brain injury. These results suggest a potential therapeutic approach that targets numerous outcome parameters simultaneously.

Keywords: high intensity focused ultrasound
HUCPVC
Secretome
Traumatic Brain Injury
Zebrafish
Advisor: Baker, Andrew J
Examining the Development of a Community of Practice in Paediatric Project ECHO®

Paediatric Project ECHO® is an innovative, interactive educational model for healthcare providers (HCP) based on the community of practice (CoP) concept, that expands access to and capacity for providing evidence-informed care. This study examined the development of a CoP in Paediatric Project ECHO and barriers and facilitators to its development. A qualitative description design was undertaken with semi-structured, audio-taped interviews. Twenty-one HCPs participants were interviewed. Participants’ responses indicated evidence for CoP concepts including social interaction, knowledge sharing, knowledge creation, and identity building. The main barriers to CoP development were differences in participants’ perceptions of the program aims and challenges in making time to participate in the program. The main facilitator was the interactive program format. This is one of few studies to demonstrate how knowledge creation occurs in an intentionally created CoP. Further development and clarification of the CoP concept for the ECHO model is needed to enhance program delivery.

Keywords: community of practice
continuing education
paediatrics
Advisor: Stinson, Jennifer
Lalloo, Chitra
The Effect of Free Distribution of Essential Medicines on Adherence by Income Sources and Level

Introduction: Public policies aimed at improving medicine adherence are restricted to people with a low income or to social assistance recipients. Objective: To determine whether the free provision of essential medicines has a different effect on adherence for people with different income levels and sources. Methods: In this post-hoc subgroup analysis of results from the CLEAN Meds randomized control trial, binary logistic regression was used as the primary analysis to determine whether free medication provision has different effects at different income levels and sources. Results: Despite the evidence to suggest that the RCT intervention has a significant effect on adherence (p=0.02), there was no substantial difference in the effect of free medicine distribution for people with different income levels or sources (p=0.73). Conclusion: The results of this study do not support the idea that programs aimed at improving access to medicines mostly improve adherence for those of certain income groups.

Keywords: Drug adherence
Drug care
Essential medicine
Income drug adherence
Pharmacare
Universal drug care
Advisor: Persaud, Navindra
A Preliminary Study of the Nociceptin Receptor System in Individuals with Psychosis

Psychosis is characterized by key positive symptoms and evidence potentially implicates the nociceptin receptor (NOPr) system in these processes. This pilot study investigates in vivo NOPr expression in individuals on the psychosis spectrum using the [11C]NOP-1A radioligand and positron emission tomography (PET). Evidence for dysregulation in dopamine, glutamate, and the hypothalamic-pituitary-adrenal axis is presented, followed by evidence of NOPr involvement in each of these systems. This pilot study aimed to assess feasibility, including recruitment, study procedures, and timeline, and also sample size estimation. Eight individuals with psychosis and eight healthy control individuals successfully completed study procedures. Results demonstrate that a total of 25 individuals would be needed in each group to detect a 20% difference between groups with 80% power and an alpha of 0.05, and the methodology employed in this internal pilot study would be appropriate to conduct a study with a larger sample size in the future.

Keywords: nociceptin receptor
PET
psychosis
Advisor: Kolla, Nathan
Design and Behaviour of a Composite Glass-Fibre-Reinforced Polymer and Ultra-High-Performance Fibre-Reinforced Concrete Box Girder

This thesis presents the design, fabrication, and experimental performance of an innovative composite box girder built using ultra-high-performance fibre-reinforced concrete (UHPFRC) and glass-fibre-reinforced polymer (GFRP). This girder incorporated the novel use of UHPFRC on the tensile side of the beam for increased flexural stiffness. A robust studded and textured surface developed specifically for use with UHPFRC was used to effectively bond the concrete and GFRP together. Under four-point bending the composite system showed a good agreement with theoretical predictions. The impact of shear stiffness on girder performance was highlighted, and vibration testing was utilized to estimate the dynamic properties of the system. Pertinent design details were addressed through the review and application of classical lamination theory and orthotropic stability expressions.

Keywords: Bridge Engineering
Classical Lamination Theory
Composite Box Girder
GFRP
Plate Stability
UHPFRC
Advisor: Gauvreau, Paul
The Root of Harmonic Expectancy: A Priming Study

The purpose of this study was to determine whether harmonic relations apply across both musical (notes to chords) and perceptual levels (audiovisual integration). The hypotheses predicted that the perceptual system can (1) interpret a single note to create a harmonic expectancy, and (2) interpret the visual image of piano notation to form a harmonic expectation. Experienced musicians participated in a musical in-tune/out-of-tune priming paradigm with auditory, visual, and audiovisual prime stimuli. The auditory chord target in each pair was either harmonically related or unrelated to the prime. Mean reaction time and error were recorded for each participant. There were significant interactions in all conditions except for music notation, indicating an expectancy for an auditory musical stimulus—a full chord or a single note—to be followed by a related in-tune chord target. These results provide novel evidence that a single root note facilitates spreading activation and creates a harmonic expectancy.

Keywords: Expectancy
Harmony
Music Perception
Priming
Spreading Activation
Tonality
Advisor: Schmuckler, Mark A
Wireless Charger for Electric Vehicles with Electromagnetic Coil Based Position Correction

Wireless Power Transfer (WPT) is an enabling technology for the mass deployment of Electric Vehicles (EVs) as it minimizes driver intervention during the charging process. Major challenges of WPT systems include coil misalignment and large air-gap, as both degrade efficiency. To address these issues, a vertically-mounted compact dual-coil charging pad for reduced air-gap is presented in this thesis. A linear-slider-mounted transmitter pad allows for lateral self-alignment using two integrated electromagnetic coils. Due to parking accuracy, the vertically-mounted charging pads increase variation in the air-gap, which degrades the electromagnetic coil operation. A position-correcting control algorithm that detects the system impedance and resonant frequency is proposed for improved pad alignment. An experimental prototype achieves a peak DC-DC efficiency of 90.1%. The charging pads laterally align in 1.75s and correct misalignments as large as 240mm. The control algorithm is successfully demonstrated with the pads being corrected to within 10mm of perfect alignment.

Keywords: Electric Vehicles
Inductive Charging
Position Correction
Wireless Power Transfer
Advisor: Trescases, Olivier
A Three-phase Fully-integrated Battery Charger for Electric Vehicles Offering Galvanic Isolation

Integrated chargers leverage the drivetrain system existing on-board Electric Vehicles (EVs) to minimize dedicated charging circuitry and associated infrastructure cost, thus removing a major barrier to widespread deployment of EVs. This thesis proposes a fully-integrated charger system for EVs by utilizing a double-stator winding induction machine. The proposed charger uses three-phase AC-grid voltage to provide fast charging feature. Unlike the majority of integrated EV chargers, the proposed topology provides galvanic isolation between the grid and EV battery during the charging processes. The proposed integrated charger is able to regulate the active and reactive power exchange between the utility grid and EV, separately; thereby, it can charge EV battery with unity power factor operation. Moreover, this topology provides bidirectional power transferring capability to support G2V and V2G applications. The performance of the proposed integrated charger is verified through simulation and experimental results by using two wounded-rotor induction machines with inter-connected rotor windings.

Keywords: Electric Vehicle
EV charging
Fast Battery charger
Induction Machine
Isolated integrated charging
Advisor: Lehn, Peter
Bacteriophage Moron JBD30-4 Affects type IV pilus and Flagellar Function in Pseudomonas aeruginosa

Bacteriophages can influence the virulence of Pseudomonas aeruginosa, an opportunistic pathogen causing significant morbidity and mortality in immunocompromised individuals. Morons, specific prophage genes not required for the phage life cycle, provide fitness advantages to bacteria under specific environmental conditions. JBD30-4 is a phage moron that inhibits P. aeruginosa twitching and swimming motility while remaining susceptible to phage infection. An interaction detected using the bacterial adenylate cyclase two-hybrid system suggests that JBD30-4 mediates this phenotype through an interaction with the type IV pilus response regulator PilH. Biochemical characterization of JBD30-4 revealed that the N-terminus of the protein is critical for function. Downregulation of flagella and type IV pili upon expression of JBD30-4 from a prophage, leading to a decrease in motility, may enable bacterial evasion from the host immune system during P. aeruginosa infection, promoting survival of the bacteria and the prophage genome contained within it.

Keywords: Bacterial motility
Bacteriophages
Cystic Fibrosis
Infectious disease
Phage morons
Pseudomonas aeruginosa
Advisor: Maxwell, Karen
Modeling for Social Network Privacy Design

Social networking sites (SNSs) are facing a challenge – to manage the privacy concerns expressed by users while satisfying the data harvesting demands from partners. To alleviate the privacy issues on SNS platforms, researchers have been proposing solutions from policy enforcement to technological enhancement. However, many proposals only focus on one or several specific privacy-related requirements while ignoring the others. For instance, purely technological solutions tend to sacrifice commercial feasibility or user acceptance. This gap suggests the need for a systematic and integrated approach to guiding the analysis towards social network privacy and to searching for viable solutions. This thesis applies goal-oriented modeling techniques in the information systems area to study SNS privacy. In particular, the i* modeling language, is explored and evaluated regarding its abilities to conceptualize actors and relationships, and to reason about design alternatives in the context of SNS privacy.

Keywords: Goal-oriented modeling
Privacy
Social networking sites
Advisor: Yu, Eric
Developing an Advanced Hardware Testing System to Enable Rapid Spacecraft Manufacturing

The use of small satellites in commercial constellations has attracted much attention in recent days. This necessitates the need to utilize innovative solutions to building multiple identical satellites both quickly and economically. An automated test system is developed for mass production and verification of hardware. It eases the repetitiveness in production verification tests, reduces human errors and increases reliability. The thesis addresses challenges in large-scale hardware testing with a particular focus on two primary areas: (i) specific process and challenges in building a spacecraft power subsystem; and (ii) testing hardware at a large-scale. The first part of this thesis presents the challenges affiliated with hardware production and validation tests. The second part presents the framework developed to generate and track hardware manufacturing information. The third part details the design and implementation of a system comprising of algorithms, instrumentation, and data acquisition units that interface with the device under test.

Keywords: automation
hardware
satellites
space
spaceraft
testing
Advisor: Zee, Robert E
A Physics-constrained Three-dimensional Three-component Particle-based Velocimetry Method for Constant-density Flows

A physics-constrained method of inferring three-dimensional three-component (3D3C) velocity fields in constant-density flows from reconstructed 3D Mie-scattering fields of tracer particles is introduced. The proposed method is based on the representation of the estimated velocity field as a linear combination of divergence-free polynomial basis functions; the piecewise constant representation of the estimated velocity field that is inherent to tomographic particle image velocimetry (T-PIV) is replaced by a smooth representation that automatically satisfies conservation of mass. The appropriate linear combination is determined using a non-regularized motion estimation framework that is influenced by optical flow motion estimation. A detailed evaluation of the proposed method is provided in terms of accuracy and spatial resolution, treating 3D constant-density direct numerical simulation data as the ground truth. It is shown that the proposed method (i) yields as much as a twofold improvement in both accuracy and spatial resolution compared to an idealized implementation of T-PIV and (ii) achieves comparable accuracy and spatial resolution to an idealized estimate that corresponds to the theoretical one-vector-per-particle limit.

Keywords: Divergence-free polynomial basis functions
Fluid velocimetry
Optical flow motion estimation
Scalar image velocimetry
Advisor: Steinberg, Adam M
Yano, Masayuki
Evaluating Team Unbreakable: A Running Program to Improve Adolescent Mental Health

Adolescents are disproportionally affected by mental illnesses like anxiety and depression. Physical activity is an accepted modality for improving adolescent mental health. One physical activity-based program is Team Unbreakable. Widely implemented, no formal evaluation has been conducted to date. Drawing on theoretical tenets of the mastery and social support hypotheses, the present study explored the program’s effectiveness and mechanisms of action through a quasi-experimental, mixed-methods design. Participants (nintervention=58; ncomparison=62; Mage=14.8 years) completed pre- and post-questionnaires on measures of anxiety and depression symptoms, mastery, and social connectedness. Individual interviews were conducted with participants (n=10) to capture program experiences. Repeated measures analysis of variance and mediation analysis indicated no significant effects on outcome variables. Inductive thematic analysis demonstrated that the program was evaluated favourably and theoretical tenets were noteworthy in the participants’ accounts. Findings suggest that mastery and social support are valuable program components, but further exploration of these mechanisms is necessary.

Keywords: Adolescent
Anxiety
Depression
Mental health
Physical activity
Program evaluation
Advisor: Sabiston, Catherine M
Investigating the Role of Crossmodal Phase Resetting in Audiovisual Binding

The mechanisms allowing the brain to fuse paired auditory and visual stimuli into a unified percept, despite differences in their timing, remain largely unknown. Crossmodal phase resetting of ongoing oscillations by the leading stimulus may facilitate integration of the following stimulus by establishing a shared temporal structure within a network of primary and multisensory areas. EEG was recorded during a simultaneity judgment task to assess whether phase resetting (measured as intertrial coherence) differentiates ambiguous stimuli that are perceived as fused and those perceived as segregated. No differences in intertrial coherence were observed between fused and segregated trials, however differences in ERP amplitude tracked perception in auditory-leading trials. Source modelling of this difference identified a network previously implicated in the perception of intersensory asynchrony, comprising both unisensory and multisensory cortical regions. Additionally, a correlational relationship was identified between individual sensitivity to asynchrony and intertrial coherence elicited by nearly synchronous stimuli.

Keywords: cognitive neuroscience
crossmodal interactions
EEG
multisensory integration
neural oscillations
perceptual binding
Advisor: McIntosh, Anthony Randal
Alain, Claude