VictorJuiz/thesis huggingface dataset:
Rapid Coding of Scene Features via Ensemble Statistical Processing

Ensemble perception utilizes patterns in our visual field to quickly and accurately process summary statistics for multiple types of information. Typically investigated used object and face ensembles, no known experiment has addressed the statistical coding of scene ensembles, despite a neuroanatomical link between scene and ensemble perception (Cant Xu, 2012). For this study, spatially derived scene ensembles were examined, and average scene features of content (measured by levels of perceived naturalness and manufacturedness) and spatial boundary (measured by how open or closed the scene ensemble appears) were rated. It was found that: a) average ratings given for a scene ensemble will be correlated with the average of the ratings given for the individual scenes comprising the ensemble, and b) scene ensemble ratings can occur both rapidly and accurately in a fraction of a second.

Keywords: Ensemble
Lateral occipital cortex
parahippocampal place area
Perception
Scene
Visual neuroscience
Advisor: Cant, Jonathan S.
Nestor, Adrian
A Comparison of Augmented Feedback and Didactic Approaches to Reduce Spine Motion During Box and Paramedic Lifting Tasks

Injury prevention movement (re)training (MR) for paramedics may be improved if they were guided by biomechanical and motor learning principles. The purpose was to compare MR approaches – didactic (DID) and augmented feedback (AUG) – in reducing spine motion during lifting tasks. Untrained participants (n=26) began with a lifting test (box, medication bag, and backboard), followed by their randomly-assigned intervention involving 50 practice lifts. The DID group began with a safe lifting presentation, whereas the AUG group was coached with augmented feedback. The lifting test was performed immediately and one-week after, while spine kinematics were quantified. After one week, AUG was strictly superior to DID in reducing spine motion in the retention task but was equivalent or superior for the transfer tasks. An AUG approach to MR is supported over didactic approaches to elicit lasting changes in practiced tasks, but more training is likely required to ensure transfer to unrehearsed tasks.

Keywords: biomechanics
ergonomics
Injury prevention
low back disorder
movement (re)training
paramedic lifting
Advisor: Beach, Tyson AC
Mackenzie Health: An Analysis of a “Smart” Internet of Things Approach to Healthcare

Background: Providing good quality patient care is challenging in today’s busy healthcare environment. Faster response times to patient calls have been shown to reduce the risk of falls, length of stay (LOS), and improve patient satisfaction. One hospital, Mackenzie Health has implemented a new “smart’ pilot unit with various Internet of Things (IOT) connected technologies with the goal of improving care. Methods: Data collected by the new system was statistically compared to historic data to determine the impact. A discrete simulation model was also built to explore further potential improvements in how patient calls could be routed. Results: Mean and median call response times improved by ~5% and ~31% respectively. Employing alternative call routing strategies can further improve response times and nurse travel distances. Conclusion: This study lends evidence to the argument that the adoption of ubiquitous smart technology in healthcare can improve operations and reduce inefficiencies.

Keywords: Clustering
eHealth
Healthcare
Nursing staff
Patient call bell
Simulation
Advisor: Carter, Michael W
Cafazzo, Joseph
A GPU-Based High Performance Particle Image Velocimetry Algorithm for Characterizing a Flow Control Actuator

A GPU-accelerated PIV data analysis algorithm was developed. The algorithm was vigorously validated using both synthetic images and experimental data. The algorithm was run on a GPU cluster and in the best case was ∼ 10× faster than when run on a CPU. 20,000 PIV image pairs were collected and processed using the GPU-PIV algorithm to study the effectiveness of an oscillating piezoelectric jet actuator for flow control. The mean velocity and Reynolds stress data indicated two distinct regions in the actuator’s jet: one region near the nozzle exit dominated by the pulsating nature of the jet, and another downstream region which resembled a fully-developed turbulent jet. Vorticity data showed the formation of counter-rotating vortices produced by the jet near the exit. Overall, the results indicate that the actuator will be an effective flow control device.

Keywords: Flow Control
GPU
PIV
Turbulence
Advisor: Sullivan, Pierre
Topology Design of Concentric Tube Manipulators Using Optimization

One of the major problems facing the development and road to practical usage of concentric tube continuum robots in surgical environments is that of instability. This issue, also known as the snapping problem, is caused by a tube having a high bending to torsional stiffness ratio (BTSR). Past efforts have shown that by cutting patterns on the tubes, this problem can be avoided. This thesis seeks to redesign the topology of the tubes so that BTSR is decreased and the snapping problem is resolved in a particular tube set. The generated designs were then validated through finite element analysis as well as experimental testing to demonstrate the elimination of the snapping problem. Using this novel tube design in concentric tube robotic systems can increase stable workspace because it allows the usage of greater tube curvatures and/or curve lengths. 同心管机器人的研究和应用中，操纵器的不稳定性是一个困扰研究者的严重问题，可能出现的不稳定跳动现象成为手术环境下使用同心管机器人的一大障碍。这种跳动由管子的挠度与抗扭刚度之比（BTSR, Bending to Torsional Stiffness Ratio）过高造成。过往研究表明，可以通过用机床在管子上切出方向性图案来降低BTSR值。本文旨在通过多种优化方式重新设计一套能够降低管子BTSR值的切割图案，允许操纵器在更大范围内活动而不再发生不稳定跳动。管子的模型通过拓扑优化生成，且每根管子的性质都由有限元分析得来。如此，我们能在生产样本之前有大量不同尺寸管子的设计，从而对其刚性和受力效果作出判断。我们对切割完的样本测验得出其真实BTSR值。结果显示，设计出的管子的BTSR值被有效降低，在同心管系统中使用时，被切割过的同心管操纵器在运动中没有出现不稳定的跳动现象，这样设计出来的同心管操纵器可以直接扩大操作空间，并增加可到达的坐标。本文的结论有助于同心管机器人早日在手术中得到应用。

Keywords: concentric
optimization
robot
surgery
topology
tube
Advisor: Drake, James
Characterizing Neuropathic Pain in the Naked Mole-Rat (Heterocephalus glaber)

The nociceptive system of the African naked mole-rat (Heterocephalus glaber) contains unique adaptations that make the species insensitive to skin pain from some chemical stimuli. Sensitivity to thermal and mechanical stimuli are hallmark symptoms of chronic pain following nerve injury. Upon damage, a cascade of molecular signals is released and contribute to chronic pain. To determine whether naked mole-rats develop long-lasting sensitivity, I adapted the spared nerve injury rodent model and applied the model to subordinate males and females of soldier and worker status. I then measured behavioral responses to mild and strong mechanical stimuli and a mild cold stimulus. Hypersensitivity to both mild and strong mechanical stimuli were comparable between naked mole-rats and mice following nerve injury. Unlike mice, naked mole-rats showed no reaction to mild cold after nerve injury. This non-response to mild cold could arise from unusual connectivity or atypical receptor expression or function. Le système nociceptif du rat-taupe africain nu (Heterocephalus glaber) contient des adaptations uniques qui rendent l’espèce insensible aux douleurs de la peau causées par certains stimuli chimiques. La sensibilité aux stimuli thermiques et mécaniques est un symptôme caractéristique de la douleur chronique consécutive à une lésion nerveuse. Pour déterminer si les rats-taupes nus développent une sensibilité durable, j'ai adapté le modèle de rongeur lésé au nerf épargné et appliqué le modèle aux subordonnés mâles et femelles ayant le statut de soldat et de travailleur. J'ai ensuite mesuré les réponses comportementales à des stimuli mécaniques légers et forts et à un stimulus froid léger. L'hypersensibilité à des stimuli mécaniques légers et puissants était comparable chez les rats-taupes nus et les souris après une lésion nerveuse. Contrairement aux souris, les rats-taupes nus ne présentaient aucune réaction au froid léger après une lésion nerveuse.

Keywords: naked mole-rat
neuropathic pain
nociception
rodent behavior
social status
TRP receptors
Advisor: Martin, Loren J
Holmes, Melissa M
Striving to Do No Harm and yet Respect Patient Autonomy: Ontario Plastic Surgeons’ Perspectives of the Consultation for Breast Reconstruction with Women Who Have Early Stage Breast Cancer

Background: The rate of contralateral prophylactic mastectomy (CPM) has doubled over the previous decade in women with early-stage breast cancer. Despite the strong association between CPM and breast reconstruction, little is known about the clinical encounter between patients and plastic surgeons. Purpose: A qualitative study aligned with the constructivist paradigm was conducted to understand how plastic surgeons describe their roles in the decision-making process through their consultations with women who have early-stage breast cancer. Methods: Semi-structured interviews were conducted with Ontario plastic surgeons. An inductive and interpretive thematic approach was used to analyze the data. The four principles of biomedical ethics were used as the conceptual lens to interpret the findings. Results: Four themes were identified: maintaining non-maleficence, supporting patient autonomy, delivering (un)equal healthcare, and providing care to enhance well-being. Conclusions: Plastic surgeons must balance competing responsibilities to do no harm and support a patient’s right to autonomous healthcare decisions.

Keywords: Breast Reconstruction
Contralateral Prophylactic Mastectomy
Early Stage Breast Cancer
Ontario
Plastic Surgeon
Treatment Decision Making
Advisor: Wright, Frances C
Aeroacoustic Noise Prediction and Acoustic Optimization of Mufflers

Noise control of large diesel and natural gas generators is achieved through industrial mufflers. Design of such mufflers relies heavily on general guidelines. But these guidelines are not suitable for complex mufflers; instead, automated optimization provides an effective means of design. Optimization of a plug flow muffler (PFM) is conducted in this work with two different approaches: 1) a relatively simple gradient-descent algorithm (L-BFGS-B) maximizing the transmission loss of the PFM, and 2) a multi-objective (transmission loss and pressure drop) simulation-based optimization using the Efficient Global Optimization (EGO) algorithm. The EGO algorithm is shown to be well suited for muffler optimization, performing vastly better than the commonly used NSGA-II algorithm. In addition, the initial steps towards the prediction of aeroacoustic noise (self-noise) in mufflers is accomplished through the CFD simulation of the tandem cylinder benchmark experiment.

Keywords: aeroacoustics
muffler
optimization
plug flow muffler
simulation-based optimization
tandem cylinder
Advisor: Sullivan, Pierre E
The Role of the Physician in the Reach and Adoption of Online Health Resources - A Qualitative Study of the Perspectives of Patients and Health Care Providers

Introduction: Prostate cancer (PCa) patients are living longer with side effects of their treatments, which are often debilitating. Online health resources (OHRs) could provide PCa patients with health information and support needs they often lack. Purpose: To understand the contextual aspects of reach and adoption within the RE-AIM framework, and how they inter-relate through the role of the physician within the context of online health resources. Methods: Secondary qualitative analysis using data collected to inform the design of an interactive OHR. Inductive/deductive hybrid analysis was used. Results: Findings yielded three main categories of use and uptake of online health resources by patients: reach, patient uptake of OHRs, and physician uptake of OHRs. Conclusions: By contributing to both reach and adoption, physicians can increase patients’ use of OHRs. These findings can improve the implementation OHRs for patients, fulfilling the need for information that PCa survivors have and increasing their quality of life.

Keywords: Adoption
Implementation
Physician Role
Reach
RE-AIM
Advisor: Gilbert, Julie
Cockerill, Rhonda
Impact of Low Coagulant Dosages on Protein Fouling of Ultrafiltration Membranes

Ultrafiltration fouling in drinking water treatment has been primarily attributed to the biopolymer fraction (e.g., proteins) of organic matter in source waters. This bench-scale study examined the use of coagulation to mitigate fouling in three model protein solutions. Similar to results from studies conducted with natural waters, a low coagulant dose (2 µM Al) was identified to significantly reduce membrane fouling relative to zero coagulant addition for two proteins (BSA and ovalbumin). It is hypothesized that the low dosages alter the surface hydrophobicity of proteins in both the bulk solution and fouling layer, resulting in weakened intermolecular interactions, reducing fouling. The impacts of applying coagulation only during the initial stages of a permeation cycle (phased coagulation) on membrane fouling were investigated at pilot-scale. Coagulant application during the first half of the cycle resulted in fouling rates similar to that of continuous addition, which could translate to significant cost savings.

Keywords: coagulation
fouling mitigation
protein fouling
ultrafiltration
Advisor: Andrews, Robert C
Impact of the Model of Long-term Follow-up Care on Adherence to Guideline Recommended Surveillance Among Survivors of Adolescent and Young Adult Cancers

We explored the predictors of LTFU care received by a population-based cohort of survivors and the impact of care on adherence to recommended surveillance. Five-year survivors were identified from a provincial administrative health database of patient’s aged 15-20.9years at diagnosis between 1992-2010. We defined four models of LTFU care: specialized survivor clinic; oncology clinic; primary care physician; no care. Poisson regression models examined attendance rates, while logistic regression models assessed guideline adherence to surveillance. For 1,574 survivors, the risk of receiving no care was highest in males and increased 7% per year of follow-up. Among those eligible for specialized survivor clinics, greater attendance was observed in females and those living closer to a clinic. Female survivors at risk for breast cancer were 2.9 times more likely to receive annual mammograms if followed at a specialized clinic. Identifying accessible care models that maximize surveillance adherence must be a key research focus.

Keywords: AYA
Survivorship
Advisor: Nathan, Paul C
The Toxicological Impact of Wastewaters on Drinking Waters Sources

Surface waters may contain wastewater effluent associated with de facto reuse which can impact their toxicological properties both before and after treatment. This study examined the genotoxic response of three surface waters containing a range of wastewater effluent (5%, 10%, and 25% by volume). The SOS ChromotestTM was used to assay the genotoxicity of both chlorinated and unchlorinated mixtures whereas toxicity index model based on the CHO comet assay was used to predict the contribution of trihalomethanes (THM), haloacetonitriles (HAN), and halonitromethanes (HNM) to overall genotoxicity of chlorinated mixtures. Wastewaters were generally genotoxic whereas raw and chlorinated surface waters were not. Mixtures containing 5% and 10% wastewater generally had similar responses to chlorinated surface waters alone; significant effects were more common at higher ratios (≥ 25%). SOS genotoxicity correlated strongly with predicted genotoxicity, DOC, and THM concentrations, suggesting that THMs may potentially serve as surrogates for toxic disinfection by-products (DBPs).

Keywords: De Facto Reuse
Genotoxicity
SOS Chromotest
Surface Water
THMs
Wastewater
Advisor: Andrews, Robert C.
Nash Equilibrium Seeking with Output Regulation

We consider the problem of Nash equilibrium seeking (NE) for games with agents subject to exogenous signals. Using the framework of output regulation, we design dynamic gradient play feedback control laws that incorporate internal models of the exogenous signals. We start by considering linear agents with linear exosignals under full-information. We incorporate a Laplacian-based consensus algorithm to handle the case of partial information. Finally, we extend this framework to handle a class of nonlinear agents subject to nonlinear exosignals.

Keywords: Control Theory
Game Theory
Multi-Agent Systems
Nash Equilibrium
Nonlinear Control Theory
Output Regulation
Advisor: Pavel, Lacra
Enstrophy Transport in Premixed Swirl Flames

Reynolds-averaged enstrophy transport budgets are measured in turbulent swirl flames using micro-tomographic particle image velocimetry (µ-TPIV) and CH2O planar laser induced fluorescence (PLIF) across Ka = 11-45. The combined contributions of baroclinic torque and dissipation to enstrophy transport are evaluated by subtracting the vortex-stretching and dilatation terms from the Lagrangian derivatives. Enstrophy production through baroclinic torque dominated over dissipation towards the product sides of the flame brushes. Enstrophy budgets, conditioned on mean progress-variable and spatial coordinates, have shown that the magnitude of baroclinic torque increases with bulk flow velocity. A conservative estimate of the relative significance of baroclinic torque to vortex-stretching was found to be constant. In contrast to DNS of flames in HIT, the significance of baroclinic torque relative to vortex-stretching remained constant with bulk flow velocity. The observed flame-scale turbulence generation towards the combustion products has implications both for turbulence and combustion closure models.

Keywords: Enstrophy transport
Micro-scale turbulence
Premixed combustion
Swirl flames
Advisor: Steinberg, Adam M.
Impact of the Innate Immune Checkpoint Inhibitor SIRPα-Fc on Immune Function

Signal regulatory protein α (SIRPα) is an inhibitory receptor expressed on myeloid cells that functions as a “healthy self-recognition” receptor by engagement with its ubiquitously expressed cell-surface ligand CD47. Disruption of the interaction between CD47 on primary human leukemia cells and SIRP on host macrophages with a decoy receptor SIRPα-Fc provokes robust leukemia cell phagocytosis and clearance. Because CD47 is widely expressed, we asked whether SIRPα-Fc administration may also impact the frequency and function of normal immune cells. To test this idea, NOD mice were treated with SIRPα-Fc and subjected to immunophenotypic, serum cytokine and complete blood cell count analyses. Modest alterations in dendritic cell (DC) populations and reduced levels of several inflammatory cytokines and platelets were observed in SIRPα-Fc compared to control Fc fusion protein-treated mice. SIRPα-Fc administration did not affect T cell activation or proliferation in a DC:T cell co-culture system suggesting safe use as an immunotherapy.

Keywords: CD47
Immunotherapy
SIRPa
SIRPα
SIRPα-Fc
Advisor: Danska, Jayne
The Learning Curve and Annual Procedure Volume Standards for Optimum Outcomes of Transcatheter Aortic Valve Replacement: Findings from an International Registry

Transcatheter aortic valve replacement (TAVR) is a technically complex procedure. Despite increasing use of TAVR across institutions, incomplete knowledge exists to describe the learning curve and minimum annual volumes for this procedure. We hypothesize that TAVR has a prolonged learning curve, as well as a high minimal annual volume to maintain competency. In this study, we analyzed data from 16 international centers comprising 3403 patients from the inception of their TAVR programs. The study identified an important learning curve, with higher mortality for the first 225 cases compared to those performed after > 300 case volume, and higher combined major complications up until a 300-case volume. In addition, the 30-day mortality was higher for centers performing

Keywords: Learning Curve
Minimal Annual Volumes
Transcatheter aortic valve replacement
Advisor: Cheema, Asim N
EFFECT OF LOW CONSISTENCY REFINING AND FRACTIONATION ON FOLDING BOXBOARDS AND DISCRETE ELEMENT MODELLING OF PLYBOND STRENGTH

The effect of using fractionation screens after primary high consistency (HC) refining and prior to low consistency (LC) refining on pulp properties being used as the middle-ply furnish of folding boxboards (FBBs) is investigated. Middle-ply furnish was a mixture of accept and reject pulps resulted from various screening designs, a range of specific refining energies (SRE), and two levels of specific edge load (SEL) and were compared with pulps with no screening stage. Fractionation and LC refining decreased refining energy consumption, and improved fibre uniformity resulting in optimum conditions for physical properties compared to the conventional refining processes. Plybond strength of multi-ply paperboards is modelled using Discrete Elements Method (DEM). Simulated three-ply boards were generated computationally and were subjected to z-directional tensile stress using ESyS-Particles software. It was found that plybond strength of simulated boards can be expressed by a scaling relationship in terms of paperboard density and bond strength.

Keywords: Discrete Element Method
Folding Boxboard
Fractionation
Low Consistency Refining
Mechanical Pulping
Plybond
Advisor: Farnood, Ramin
Investigation of an Electrospun Nanofibrous, Degradable Polar Hydrophobic Ionic Polyurethane Patch for Cardiac Tissue Regeneration

Cardiac tissue engineering (CTE) can be used to repair and replace the damaged myocardium due to coronary artery disease. An electrospun nanofibrous, degradable polar hydrophobic ionic polyurethane/polycarbonate polyurethane (D-PHI/PCNU) scaffold was generated and characterized for CTE applications. In addition, induced pluripotent stem cell derived cardiomyocytes (iPSC-CMs) were assessed for their compatibility on the D-PHI/PCNU scaffold. D-PHI/PCNU scaffolds had a high cross-linking efficiency, higher surface energy, and lower stiffness relative to PCNU scaffolds. In vivo, the D-PHI/PCNU scaffold degraded relatively slowly, but was well integrated with the surrounding tissue. Furthermore, the aligned D-PHI/PCNU scaffolds were able to support high iPSC-CM viability, adhesion, and expression of functional cardiac markers after a 7-day culture period. The iPSC-CMs had a more elongated and aligned phenotype on aligned D-PHI/PCNU scaffolds as compared to on random D-PHI/PCNU scaffolds and on TCPS. This work demonstrates the potential of using D-PHI/PCNU scaffolds as a platform for CTE.

Keywords: Biomaterial
Cardiac tissue engineering
Cardiomyocytes
Polyurethane
Scaffold
Surface chemistry
Advisor: Santerre, J Paul
Exploration of naturalistic driving data: Development of distracted driver behaviour models

Distraction is detrimental to traffic safety. This thesis provides insights into distracted driving behaviours through two research objectives explored on naturalistic driving data: 1) distraction engagement behaviours and visual attention allocation as a function of varying environmental demands, and 2) engagement in multiple types of secondary tasks. For this purpose, Naturalistic Engagement in Secondary Tasks (NEST) dataset was utilized. Through inferential statistics, it was shown that higher visual difficulty in the driving environment is associated with a decreased likelihood of distraction engagement, and a decrease in non-forward glances with the likelihood of longer glances (> 2s) being reduced to a larger extent compared to shorter ones (> 1.6s). Drivers 35 and older have reduced rates of non-forward glances compared to younger drivers. Moreover, the results demonstrate that engagement in multiple secondary task types is prevalent, and is more likely to occur in safety-critical as opposed to non-safety critical situations (baselines).

Keywords: Distracted Driving
Driver Behaviour Models
Environmental Demands
Naturalistic Driving Data
NEST Dataset
Secondary Task Engagement
Advisor: Donmez, Birsen