VictorJuiz/thesis huggingface dataset:
Atrial Electromechanical Function in Middle-Aged Endurance Athletes with and without Atrial Fibrillation

Highly endurance trained athletes have an elevated risk for developing paroxysmal Atrial Fibrillation (PAF). The cardiac response to exercise is unknown in this population. Fourteen endurance-trained (H-EA) males (56.6 ± 5.1 years) were compared to eight endurance-trained males with PAF (EA-AF) (52.5 ± 6.8 years) during cycle-ergometry at light (100 bpm) and moderate (130 bpm) exercise. Resting atrial volumes did not differ between H-EAs and EA-AFs. Left ventricular EDV, LA reservoir and LA booster volumes were significantly lower in EA-AFs during light and moderate exercise, and there was a trend for greater passive emptying during light exercise. There were no differences in phasic strain, diastolic function, or atrial electro-mechanical delay. The findings of the present study suggest that resting measures of volume and function are inadequate to identify markers of PAF in athletes. Evidence of reduced atrial phasic volumes during elevated demands may be indicative of atrial stiffening in PAF athletes.

Keywords: Arrhythmias
Athletes
Atrial Fibrillation
Cardiac Function
Risk
Advisor: Goodman, Jack M
When the Ones We Love Misbehave: Exploring Moral Processes in Intimate Bonds

How do we respond when those we are closest to behave unethically? Previous research has almost exclusively investigated individuals’ reactions to transgressions committed by strangers. Here we examined how observers evaluated close others and their misbehaviour, how close others’ misbehaviour affected observers’ own morality, and how relationship relevant outcomes were impacted when a close other, compared to a stranger, acted immorally. Participants read hypothetical transgressions (Study 1), recalled actual transgressions (Study 2), and witnessed transgressions occur in the laboratory committed by romantic partners, friends, and strangers (Study 3). Effects were consistent across Studies 1 and 2, but less so for Study 3. For the most part, participants evaluated transgressors and their unethical actions less harshly, but exhibited greater negative effects on their own morality and perceived relationship outcomes when close others acted unethically, compared to strangers. This work suggests that sharing intimate bonds with transgressors impact moral evaluations.

Keywords: Morality
Relationships
Advisor: Stellar, Jennifer
Securing Publish/Subscribe

Increased public scrutiny has led to calls for greater security regarding user data. As a widely used many-to-many communication paradigm, publish/subscribe (pub/sub) has received a significant amount of attention from researchers regarding ways in which to secure user data. In this thesis, we present the current state-of-the-art of securing pub/sub systems. We categorize the existing research, presenting what is currently achievable and identify gaps and potential areas of research. One such gap is the assumption of an initial established security parameter, shared secret or key between communicating clients. We propose a novel scheme called HyShare that does not require an unilaterally trusted, universally available, out-of-band service for the dissemination of a secret.

Keywords: Confidnetiality
Publish/Subscribe
Secret sharing
Security
Advisor: Jacobsen, Hans-Arno
DEVELOPMENT OF PAPER-BASED MALE FERTILITY DIAGNOSTICS FOR MOBILE HEALTH SCREENING

Mobile health technologies are emerging for population health screening applications. Current male fertility diagnostics lag these other health arenas in many aspects. This thesis provides novel methods to aid in and commercialize paper-based male infertility diagnostics. First, to quantify cell concentration and viability a smartphone-based colourometric imaging method was developed that corrects for environmental lighting conditions and provides quantitative measurements from paper-based tests. A fluid delivery system for the colourimetric paper-based assay was also developed. Clinical testing revealed that the device had false-positives from bacteria in some semen samples. To mitigate the false-positive issues, a companion method was developed to purify semen prior to testing. Collectively these works advance the technology and applicability of portable male fertility diagnostics in aid of fertility challenges worldwide. The Appendix reports additional recent work on the development and testing of a deep learning model to correlate single cell morphology parameters to DNA integrity analysis.

Keywords: Machine learning
Male infertility
Microfluidics
Point-of-care diagnostics
Smartphone imaging
Advisor: Sinton, David
Primary thromboprophylaxis for inpatients with advanced cancer

Introduction: Thromboprophylaxis (TP) is recommended for acutely hospitalised cancer patients; little is known about its use on palliative care units (PCUs). Methods: First, we conducted a systematic review to explore the landscape of TP use, venous thromboembolism (VTE) and bleeding rates on PCUs. We then administered a fractional factorial survey to Canadian medical oncologists and palliative care physicians exploring their attitudes towards TP using a series of vignettes. Results: The systematic review revealed heterogeneity in TP use, VTE and bleeding rates. The survey revealed heterogeneity in decision-making around TP between the two physician groups. We identified a number of patient factors that contributed to TP use; oncologists were at higher odds of prescribing TP compared with palliative care physicians(OR 2.09[95%CI 1.56-2.8]). Conclusions: True rates of TP use, VTE and bleeding on PCUs remain unclear. Greater exploration of the drivers and barriers to TP use, and physician group differences, are warranted.

Keywords: cancer
medical oncology
palliative care
thromboprophylaxis
Advisor: Krzyzanowska, Monika K
Study of Strain-tunable Optical Properties of Metal Thin-films on Elastomeric Substrates

Metal thin-films have unique optical properties and play a pivotal role in many photonic, plasmonic and metamaterial devices. The optical properties of metal thin-films cannot be easily modulated however, and as such the potential for tunable devices using metal thin-films layers is limited. We demonstrate the tunability of the optical properties of metal thin-films deposited on elastomeric substrates by way of applied tensile strain. Silver thin-films seeded by dielectric aluminum nitride layers are shown to exhibit strain actuatable infrared plasmonic resonances as a result of film crumpling when under strain. Silver thin-films seeded by chromium are shown to have local surface plasmon resonances as well as reduced infrared reflectivity when compared to smooth silver thin-films. Under strain, we show how the reflectance of these films is further decreased, and their transmittance enhanced. We conclude with a list of potential tunable optical devices that could utilize strain-tunable metal thin-film layers.

Keywords: Metal thin-film
Photonic
Plasmonic
Strained
Tunable
Advisor: Kherani, Nazir P
Cation Chloride Cotransporters Exist with NMDA Receptors in Molecular Complexes

In the central nervous system, the polarity of GABAergic synaptic transmission is predominantly determined by cation-chloride cotransporters NKCC1 and KCC2. During development, functional expression of chloride-loading NKCC1 decreases while chloride-extruding KCC2 is steeply upregulated and underlies the GABA switch from excitatory to inhibitory. Despite the critical role of KCC2 in inhibitory neurotransmission, excitatory kainate-type glutamate receptor subunit GluK2 interacts with and regulates KCC2 function. The aim of this study was to determine if N-methyl-D-aspartate receptors (NMDARs) interact with NKCC1 and KCC2. The salient findings of my work are: (i) NKCC1 and KCC2 interact with NMDARs in neurons throughout development and into maturity (ii) loss of NMDARs alters expression of KCC2 and (iii) traumatic brain injury alters cation-chloride cotransporter expression and interactions with NMDARs. This work contributes to our knowledge of the molecular interplay between the opposing forces of neuronal excitation and inhibition.

Keywords: chloride homeostasis
GABA
glutamate
KCC2
NKCC1
NMDA receptors
Advisor: Woodin, Melanie A
Mechanical Aging of Thermoset Polymer

Polymer aging is a time-dependent process of various changes to the material under the influence of one or more environmental factors. Thermoset polymers experience mechanical properties degradation when subjected to different aging conditions. It is the objective of this research to conduct accelerated tests, supported by limited MD simulations, to determine the degradation behaviors of an epoxy polymer under water immersion, UV radiation, and elevated temperature. To investigate the effect upon mechanical properties, tensile tests were conducted for more than 270 days. In addition, molecular dynamics (MD) simulations were conducted to investigate the water absorption effect on the elastic properties of the epoxy. The results revealed that water absorption has both plasticization and anti-plasticization effects; UV radiation could lead to post-curing reactions and epoxy embrittlement; thermal aging can also further cure the epoxy initially, but longer thermal aging leads to softening effect.

Keywords: Aging
Mechanical properties
Molecular dynamics
Thermoset polymer
Advisor: Meguid, Shaker A
Cell Specific Expression, Regulation and Consequences of GITRL Induction in a Persistent Viral Infection

Co-stimulation of T cells through Glucocorticoid-Induced Tumour Necrosis Factor Receptor-Related Protein (GITR) contributes to viral control during persistent lymphocytic choriomeningitis virus (LCMV) infection. Herein, we demonstrate that expression of its ligand, GITRL, is restricted to the onset of infection. GITRL induction is dependent on type I interferon (IFN-I) both in vitro and in vivo. Accordingly, monocyte-derived inflammatory antigen presenting cells (infAPC) with high IFN-I sensitivity were identified as the dominant GITRL expressers. Selective deletion of exon2 in their GITRL with Lysozyme-M-Cre recapitulated defects reported in global GITR-/- mice. Furthermore, we showed that infAPC were weak APC and phospho-signaling downstream of GITR was temporally segregated from T cell activation suggesting a post-priming event. Instead, GITR played a pro-survival role in sustaining CD4 T cell responses early post-infection through up-regulation of IL2RÎą, IL7R, and OX40. Together, this thesis provides insights into the regulation and mechanism of GITR co-stimulation during LCMV clone13 infection.

Keywords: GITR
GITRL
LCMV
TNFRSF18
TNFSF18
Type I Interferon
Advisor: Watts, Tania H
Physiological Monitoring During Cardiac Arrest: Derivation and Validation of Capnogram Algorithm

Cardiac arrests are life threatening medical emergencies that affect over 40,000 individuals in Canada each year. Cardiopulmonary resuscitation (CPR) continues to be one of the few first-line interventions that improves survival, yet there is limited understanding of how we can target CPR to internal physiological markers. Our systematic review identified a paucity of studies evaluating whether hemodynamic-directed CPR can improve patient outcomes relative to current standardized CPR protocols. We also focused on the most widely available physiological monitoring tool in resuscitation, end-tidal carbon dioxide (ETCO2), and identified a high frequency of analytical error impeding accurate measurement. We developed and evaluated novel technology capable of reducing this error, resulting in a significant improvement in accuracy. Future research should be aimed at employing the refined algorithm for measuring ETCO2 capnography to identify prognostic trends, and develop therapeutic targets that can guide care in cardiac arrest patients.

Keywords: Cardiac Arrest
End-Tidal Carbon Dioxide
Resuscitation
Advisor: Morrison, Laurie J
Bioanalytical Approaches to Investigate Antioxidant Molecules and Nucleic Acid-Protein Interactions in Alzheimer's Disease

Alzheimer’s disease (AD) is the most common cause of dementia, responsible for 60-80% of all diagnoses. Herein, we reviewed AD, concentrating on the five main factors that influence its onset (Chapter 1). Then, we introduced biosensors, reviewing the fundamentals of surface plasmon resonance (SPR) and electroanalytical techniques (Chapter 2). Next, we investigated the antioxidant activity of polyphenols and repurposed therapeutics (RPTs) for potential agents to combat oxidative stress associated with AD (Chapter 3). We then shifted our attention to investigate the ApoE4-SirT1 oligonucleotide interaction. Using electroanalytical techniques (Chapter 4) and SPR (Chapter 5), we showed that ApoE4 interacted with ssDNA but not dsDNA corresponding to the SirT1-promoter sequence. Furthermore, we showed the interaction with ssDNA was isoform specific amongst the ApoE isoforms. At present, we cannot comment on the biological implications of such an interaction, however, our findings have identified a possible ApoE4 aptamer with potential applications in biosensor technology.

Advisor: Kerman, Kagan
Electrospray In Crossflow

Characteristics of an electrospray ion source in an air crossflow is investigated. The effect of crossflow on the Taylor cone, the emitting jet, and the plume spray trajectory, are studied experimentally. The trajectory of a plume in the cone jet mode is related to the crossflow velocity, applied voltage to the nozzle, and the location of the ion source inside a dissovation chamber. An analytical model is developed for the prediction of the trajectory of an electrified jet in an electric field and a crossflow. A numerical solution is developed in order to simulate the traveling paths of single droplets inside the chamber, which is used to estimate the plume trajectory. The results of both models are discussed and compared with the experimental cases.

Keywords: Crossflow
Electrified Jet
Electrospray
Mass Spectrometry
Advisor: Ashgriz, Nasser
Characterizing the Deubiquitinase USP35

Mitophagy involves the selective removal of damaged mitochondria by autophagy. Defective mitophagy, resulting in the accumulation of toxic mitochondrial byproducts, leads to cell death; this is particularly deleterious to non-proliferating cells, such as neurons. Ubiquitination ensures the progression of mitophagy. Previously, we determined that a complex of the mitochondria localized (short, s-) isoform and full-length (l-) isoform of the deubiquitinating enzyme ubiquitin specific protease 35 (USP35) negatively regulates mitophagy. However, the biological prevalence of s-USP35 is poorly defined, and the mechanism underlying its mitochondrial association is unclear. Here, we show that the s-USP35 transcript is expressed in human breast and liver tissue. In addition, we demonstrate that s-USP35 is a peripheral mitochondrial protein. Together, our results characterize USP35 and contribute to better understanding the basis for its effects on mitophagy. Elucidating USP35â s mechanism of action is instrumental to analyzing its suitability as an enzymatic drug target for the maintenance of cellular health.

Advisor: McQuibban, G. Angus
Kim, Peter K.
Identifying Dietary Fibre and Protein Intakes and their Food Sources in a Pre-dialysis Adult Population

Background: Higher fibre intakes are associated with decreased chronic kidney disease (CKD) progression and cardiovascular disease (CVD) risk. However, knowledge is limited on the fibre intakes and dietary meal patterns in pre-dialysis. Objective: To describe the intakes of fibre and protein, and their food sources, in pre-dialysis patients and compare intakes to a healthy population. Methods: A cross-sectional, observational study, using the multiple-pass method repeat 24 hour recalls from 76 pre-dialysis CKD patients and data extracted from the Canadian Community Health Survey (CCHS). Results: The mean fibre intake of CKD patients was 17.6 (+ 10.3g/d), with 71% consuming

Keywords: chronic kidney disease
dietary fibre intake
dietary protein intake
pre-dialysis
uremia
Advisor: Darling, Pauline B
Older Adults' Acceptance of Virtual Doctors: A Preliminary Investigation

The use of virtual doctors is increasing; yet, we have not fully studied their impact and how they are perceived by the public, especially by digitally-marginalized users such as older adults. We also do not know how virtual doctors compare to other technology-mediated alternatives, like traditional telemedicine. More broadly, the factors leading to older users’ adoption of virtual doctors are not well understood. In other similar fields, users’ perceptions of early generations of conversational interfaces have been extensively studied. This raises the question of how virtual agents’ fidelity (e.g. video vs. speech-only) and agency (e.g. human vs. machine) influence confidence, comfort, and ease of use in target groups like older adults. To fill these knowledge gaps, I have conducted a mixed-methods study with older adults in which they engaged with different versions of telemedicine setups. The versions varied along the dimensions of fidelity (e.g. video vs. speech-only) and agency (e.g. human vs. machine). Analysis of interview and survey data shows that older adults were most confident and comfortable with speech-only machine-powered interfaces for general healthcare information, and with video-based link with human doctors for specific healthcare information. The findings also show that in order for virtual doctor systems to be accepted by older adults, they need to do the following: complement older adults’ visits to their existing doctors, fit their existing information practices for gathering healthcare information, and have perceived value compared to their currently available alternatives.

Keywords: Embodied Interaction
Empirical study that tells us about how people use a system
Health - Wellbeing
Human-Computer Interaction
Older Adults
User Experience Design
Advisor: Munteanu, Cosmin
Effect of the Seasonal Changes in Fuel Composition on Particulate Matter Emissions from a Gasoline Direct Injection Engine

The Ministry of Environment and Climate Change (MOECC) found that black carbons (BC) concentrations were significantly higher in summer than in winter, which could be attributed to the seasonal variations in fuel composition. This experimental study investigated the impact of fuel seasonal changes on particulate matter (PM) emissions using a Ford Focus wall-guided GDI engine. Fuels from five public gas stations having octane rating of 87 and 91 were analyzed and tested. This study demonstrated that summer fuels contained higher aromatics than winter fuels which led to higher PM emissions and BC concentrations during steady state and transient state conditions. Moreover, the removal of ethanol content resulted in lower PM emissions and BC concentrations during steady state conditions. This study suggested that an increase in aromatics in summer fuels could be root cause for higher BC concentrations, however, similar study should be performed in other engines to support this conclusion.

Keywords: Black Carbon
Gasoline Direct Injection Engine
organic Carbon
Particulate Emissions
Advisor: Wallace, James S
Morphology, crystallization, and mechanical property study of polypropylene and polyethylene terephthalate

This project covers a complete in-depth study of crystallization behavior of PP and in-situ fibrillated PET composites. Two kinds of PET, APET and CPET, were examined. SEM and DSC experiments were carried out to exam fiber morphology and crystallization kinetics. PET nanofiber was manufactured through a scalable melt spinning technology, and around 250 nm PET fiber was obtained. Isothermal and non-isothermal DSC experiments were performed. With the presence of PET nanofiber, dramatic improvement of PP’s crystallization kinetics was observed. Both Avrami and Mo’s method indicated the crystallization complexity and crystallization rate were increased. Reprocessing of fibrillated material into pellet showed moderate setback effect in PET’s promotional effect in PP crystallization. Also, the mechanical property was measured to show the influence of changed crystal structure. Increase in both the modulus and strength of the composites was observed.

Keywords: crystallization
in situ fibrillation
nanofiber
pet
polymer
polypropylene
Advisor: Park, Chul B
Reducing Bias in Lidar-Only Motion Estimation

Lidar sensors are used extensively in mobile robotics applications. As a moving-while-scanning sensor, motion estimation from lidar alone is challenging since the point-clouds measured are motion distorted. We develop a continuous-time lidar odometry pipeline based on the simultaneous trajectory estimation and mapping (STEAM) framework. Though accurate, there are biases in the estimator causing the odometry to drift over time. This thesis presents two approaches for bias reduction. First, a learning-based approach is developed, which trains a model using prior data. The model takes in point-cloud information and outputs the predicted biases. The predicted biases are then applied as a correction to improve the odometry. Next, we show that a source of estimator bias occurs when the motion model cannot sufficiently represent the underlying trajectory. We derive a novel white-noise-on-jerk motion model, and show that it outperforms the white-noise-on-acceleration motion model in the existing STEAM framework.

Keywords: Lidar
Mobile robotics
Odometry
SLAM
State estimation
Advisor: Barfoot, Timothy D
Galactose-derived Glycopolymers : Synthesis, characterization and applications

This thesis explores the synthesis, characterization and application of galactose-derived glycopolymers. Glycopolymers are synthetic polymers possessing pendant carbohydrate moeities. Desirable properties such as variable structural complexity, biological compatibility and tunable responsiveness to environmental conditions have made glycopolymers prominent in biomedical engineering applications such as synthetic tissues and targeted drug delivery. Among carbohydrates, galactose is particularly relevant in drug delivery applications due to binding with asialoglycoprotein receptors (ASGPR) overexpressed in liver cancer cells. This thesis investigates the synthesis of polymerizable galactose derivatives via organoboron catalysts to efficiently access a new class of glycopolymeric biomaterials. Notably, RAFT polymerization is utilized to synthesize well-defined glycopolymers, and a hydrogel is formed as proof of concept for potential applications.

Advisor: Taylor, Mark S.
Radio Resource Management and Transmission Modes for Two-Tier Cellular Systems

This thesis explores the paradigm of two-tier connectivity, in which secondary nodes utilizing wireless backhauling facilitate the connectivity of system users to base stations in a macro cellular communication setup. When compared to smaller cells utilizing wired backhauling to offload user traffic from macro base stations in conventional heterogeneous network approaches, secondary nodes of two-tier systems offer increased placement flexibility to connect user clusters, which is shown to be instrumental for maximizing densification gains and improving the performance of cell edge users. Depending on user distribution, utilized frequency bands and the capabilities of secondary nodes, up to 179% gains in the average and cell edge throughput rates are observed when augmenting macro cellular communication systems with secondary nodes.

Keywords: Cellular
Coverage
Heterogeneous
Networks
Two-Tier
Wireless
Advisor: Sousa, Elvino