VictorJuiz/thesis huggingface dataset:
Colorectal Cancer Screening Behaviours of South Asian Immigrants in Canada: An Exploratory Mixed Methods Study

An exploratory sequential mixed method study was conducted to explore factors that influence colorectal cancer (CRC) screening uptake and to develop an empirically-based cross culturally adapted survey to better understand uptake in average risk South Asian (SA) immigrants. Phase I was a scoping study that reviewed relevant cancer screening literature. Phase II was a focus group study with SA immigrants to explore beliefs, attitudes, and reasons for CRC screening decision-making. Phase III involved survey development by incorporating Phase I and II findings, critically appraising candidate measures, cross culturally translating and adapting into Urdu, and pre-testing using cognitive interviews. Narrative and thematic analysis of scoping study literature uncovered four themes: (1) beliefs and attitudes including centrality of family, holistic health care, fatalism, screening as unnecessary, and emotion-laden perceptions; (2) lack of knowledge; (3) barriers to access; and (4) gender differences. Focus group thematic analysis revealed three themes: (1) beliefs and attitudes such as benefits of screening; (2) knowledge and awareness of CRC and screening, experiential learning, and recommendations; and (3) support and accessibility, particularly linked to physicians. In survey development, candidate measures with good conceptual matches were identifed in the literature. Modifications were made to the Urdu survey. After pre-testing, revisions addressed general design, culture, and gender issues. This study enhanced understanding of factors that influenced cancer screening and provided insights on socio-cultural context, beliefs, attitudes, barriers, and strategies to promote CRC screening among SA immigrants in Canada. Collectively, the findings informed survey development. Future research will pilot-test the surveys and conduct reliability and validity testing. These findings can inform public health and cancer control efforts to develop relevant strategies to improve CRC screening among SA immigrants. The English and Urdu language survey will be used to advance understanding of factors that influence CRC screening among SA immigrants in Ontario, Canada.

Keywords: Canada
colon cancer screening
early detection
health behavior
Survey
Advisor: Bierman, Arlene S.
Long Fiber Extrusion and Improved Energy Absorption Behaviour of Hybrid Thermoplastic Composite

The aim of this study was to develop thermoplastic biocomposites of polypropylene (PP) and jute fibers (J) with high energy absorption and without decline of strength and stiffness properties. The preparation of thermoplastic composite is a challenging task; this research presents manufacturing thermoplastic biocomposite using direct long fiber thermoplastic (LFT) extrusion technique. The soft and tough viscose fibers were used as impact modifier. The energy absorption of the composites was studied using notched izod, charpy and instrumental falling weight (IFW) impact tests. In addition fiber breakage during the extrusion process, heat deflection temperature (HDT), viscoelastic behaviour, fracture toughness, fatigue life, interfacial shear (ISS) strength and fiber dispersion were experimentally evaluated The optimum mechanical properties of the PP-J composite including toughness was found with the addition of 10 wt% of viscose fibers and 2 wt% maleated polypropylene (MAPP) as compatibilizer. Heat deflection temperature values reduced with addition of viscose fibers whereas the MAPP addition improved the values form 140 to 145°C. Consecutively, the composites viscoelastic behavior was studied using dynamic mechanical analysis (DMA), the study showed broadening of tan δ peak without change in the peak position on the compatibilized impact modified composite. The higher fracture toughness and fatigue life was also recorded on MAPP modified jute-viscose-PP-composite due to increased work energy by hindering the propagation of crack. The fractography micrographs of surface modified composites indicated clear debonding and pullout of fibers due to the flexible interphase developed between the fiber and matrix. The fiber dispersion seen in SEM images showed that toughest viscose fibers retained as larger bundles in the composites compared to more individual separated jute fibers. It is difficult to disperse viscose fibers due to their soft and tough nature. However to utilize potential of the fibers in the composite, the improvement in fiber dispersion was achieved by increasing the shear during extrusion process. This work demonstrated that it is possible to use the long viscose fibers as impact modifier to produce LFT composites. The addition of tough viscose fiber improved the energy absorption of long jute reinforced thermoplastic composites through toughening mechanism without much sacrifice in strength and stiffness.

Keywords: ENERGY ABSORPTION
HYBRID COMPOSITE
LONG FIBER EXTRUSION
MECHANICAL PROPERTIES
THERMOPLASTIC
Advisor: SAIN, MOHINI M
NAYAK, SANJAY KUMAR
The Content, Development and Use of Shared Task Representations during the Selection and Planning of Joint Actions

Many of the actions that humans perform everyday are completed with co-actors. Cognitive theories of joint action posit that shared task representations form during joint actions and that these representations help co-actors anticipate and monitor each other’s actions. However, due to the paucity of research where co-actors have to select, plan and execute actions while attempting to achieve a shared goal, there are many unanswered questions concerning how shared task representations contribute to joint actions. The common coding theory of perception and action was used to develop hypotheses concerning the content, development and use of shared task representations. To test these hypotheses, seven experiments were completed that required pairs of individuals to perform sequential joint actions. The investigation of the response selection and planning of the initiator revealed information pertaining to the content, development and use of shared task representations. The main conclusions drawn from the research are that: 1) shared task representations contain social factors that influence the motor strategy; 2) individuals can represent the difficulty associated with their co-actor’s action and select and plan actions that make their co-actor’s task easier; 3) individuals can represent multiple potential actions, and multiple features of those actions, and use information derived from the simulation of those actions during response selection and planning; 4) individuals can adopt multiple frames of reference so that they can plan actions based on information derived from allocentric, egocentric and other-person body-centered frames of reference; 5) shared motor representations are limited in content in comparison to individual motor representations; and 6) the content and use of shared task representations are enhanced by visual feedback, anticipatory motor planning and first-hand motor experience. The findings of this dissertation provide significant contributions to theories of how shared task representations facilitate the achievement of shared goals in joint actions.

Keywords: Joint Action
Motor Control
Motor Learning
Motor Representations
Response Planning
Shared Task Representations
Advisor: Welsh, Timothy N
Vacuum Infusion Molding of Natural Fibre Reinforced Biobased Resin Composite

The increasing demand in the field of bio material research for an in-depth understanding of processing phenomenon to convert it into a useful product is essential. Besides, there is inadequate information regarding the dependency between their processing mechanism and mechanical performance. The main focus of this work is to address the issues of the resin flow behavior of natural fibre in vacuum infusion molding, the determination of permeability and validation of the proposed contact angle model with experimental data. The proposed model shows greater accuracy when validated with experimental observation. The outcome of this research emphasizes the wetting mechanism and fibre network of sisal mats are the major factors that reduces 26% of permeability as compared to glass fibres. In addition, it is observed that the swelling phenomenon had a minimal influence on the permeability of the sisal fibre mat. The complex phenomena occurring during wetting of natural fibres with epoxidized soybean oil (ESO) in terms of contact angle and surface energy are investigated. The fibres are treated with various reagents to improve the wetting behavior. It is noted that NaOH treatment provides considerable amount of increase in surface area of the exposed cellulose that aids in enhancement of wettability characteristics by increasing the surface energy from 18 mN/m to 23.5 mN/m while reducing the contact angle from 530 to 310. Conversely, there is a formation of virtual layer on the fibre when treated with silane and isocyanate. Moreover, isocyanate treated fibre exhibits improved wetting behaviour in terms of increase in surface energy from 18 mN/m to 25.5 mN/m when wetted with ESO. The kinetics study of the curing reaction of the resin is performed by differential scanning calorimetry. A new empirical model is proposed to analyze the kinetic data obtained experimentally. The results highlighted that the proposed model attained significant improvement to predict the experimental cure kinetic data qualitatively and quantitatively. The addition of 30% ESO in the conventional system increases the activation energy of the system up to 108 kJ/mol. The effect of the surface treatments of natural fibre, fibre loading direction, and resin flow direction on the tensile properties of developed composites are investigated. The longitudinal tensile strength of developed composites demonstrated a 7-8 fold increment, as compared to the transverse direction tensile strength. The flow along the fibre provides 10% increment in tensile strength due to higher permeability.

Keywords: Bio composite
Manufacturing
Modeling
Natural fiber
Permeability
Wetting
Advisor: Sain, Mohini M
Nayak, Sanjay K
Non-anemic Iron Deficiency and Health Outcomes in  Pre-school Children

There is a gap in evidence on the epidemiology, diagnosis and management of non-anemic iron deficiency (NAID) in young children. Using the data from a community practice-based research network (TARGet Kids!) four studies were conducted to enrich the evidence-base related to NAID in Canadian pre-school children. The prevalence of NAID was found to be 7% (95% CI, 5.95%-8.05%). Risk factors significantly associated with NAID included younger age (OR 1.08; 95% CI: 1.06, 1.11), higher zBMI (OR 1.22; 95% CI: 1.01, 1.48), longer duration of breastfeeding (OR 1.05; 95% CI: 1.01, 1.08) and volume of cow’s milk intake (OR 1.13; 95% CI: 1.01, 1.26). Practice patterns associated with the management of NAID by community physicians showed substantial variation. Follow-up laboratory tests showed 65.5% had resolution, 25.9% had persistence and 3.4% had progression of NAID to IDA. To identify clinically important thresholds for serum ferritin (SF) in diagnosing iron deficiency in children a restricted cubic spline regression analysis was performed. A spline curve showing the association between hemoglobin and SF identified: a threshold for SF (17.9 µg/L) where the clinical impact of iron deficiency may not come into effect until values lower than this cut-off has been reached; and a SF cut-off (4.6 µg/L) that may have clinical impact on the neurodevelopment of children. To assess the effectiveness of iron interventions in children with NAID, the protocol for a multi-site, pragmatic, placebo controlled, superiority randomized trial was described (OptEC trial). The protocol included the methods of an internal pilot study, performed to recalculate the sample size and assess the adherence rate in children enrolled in the OptEC trial. Using internal pilot study data, the initial sample size (Na =112-198) was recalculated to range between 32-56 subjects. Adherence rate ranged between 14% -100% and 44% of the children had an adherence ≥ 86%.

Advisor: Parkin, Patricia C
Designing an Assessment Program for the Competency-based Era

Background The introduction of CBME at the University of Toronto division of orthopedics is an opportunity to examine the concepts of CBME. While much has been written about CBME’s potential advantages and disadvantages, further research is required to support this new model of training. Aims The first aim was to develop and evaluate a program of performance-based, in-training assessment tools, covering the breadth of competencies including clinical skills, the intrinsic CanMEDS roles, and performance of technical procedures. The second aim was to use these assessments to examine the premise that all residents can achieve a minimal level of competency after a subspecialty rotation. Results The sports medicine OSCE and OSATS were used to assess clinical skills and performance of technical procedures respectively. Each of these assessment tools demonstrated a significant difference in performance between junior and senior residents, with many junior residents unable to achieve a minimal level of competence. As a result, a modified Angoff method of standard setting was used to set different pass marks for junior and senior residents when assessing clinical skills. Using simulation to assess resident performance of Entrustable Professional Activities, many junior residents were not able to achieve a minimal level of competency, despite having been previously deemed competent. Finally, an OSCE used to assess residents’ application of the intrinsic CanMEDS roles demonstrated a significant difference in performance between resident groups depending on year of training. Conclusion The assessment tools used to assess clinical skills, intrinsic CanMEDS roles, and performance of technical procedures demonstrated sufficient evidence of validity for use in CBME. These assessments demonstrate that many junior residents are not able to achieve a minimal level of competence. These findings affect the fundamental concept of achieving competence before progression in CBME, and lend credibility to hybrid versions of CBME.

Keywords: Assessment
Competence
Competency-based Medical Education
Medical Education
Orthopaedics
Residents
Advisor: Hodges, Brian
Leading Change from the Middle: An Exploration of Leadership Competencies to Assist Ontario College Associate Deans and/or Chairs be Successful in Their Roles

This purpose of this study was to explore the role of the Ontario colleges of Applied Arts and Technology (CAAT) Associate Dean and/or Chair, and specifically focus on an investigation of leadership competencies that would help them to be successful in their roles. The study is situated within the context of changes currently taking place within the Ontario college system. The study followed a sequential mixed methodology method. Online surveys were used to gather data from Associate Deans and/or Chairs as well as Deans from the 22 English language colleges in the Ontario CAAT system. Follow up interviews were conducted with a purposeful sample of seven Associate Deans and/or Chairs. Finally, institutional documentation was gathered from Human Resources departments across the Ontario CAAT system. Data gathered focused on gaining a deeper understanding of the role and responsibilities of the Ontario college Associate Dean/Chair, an exploration of leadership competencies that would help them to be successful, and a review and assessment of leadership development opportunities currently available to them. Conclusions drawn from the study indicate that change occurring in the Ontario college system is re-defining the role of the Associate Dean/Chair, led primarily by the proliferation of degrees, and to a lesser extent, the heightened importance placed on research, expansion of flexible delivery, increases in international students, and effects of the Strategic Mandate Agreements. These changes are exacerbated by budget constraints/reduced funding and all contribute to an ever increasing workload for the Ontario college Associate Dean/Chair. The study also concluded that a substantial number of Ontario college Associate Dean/Chairs would benefit from enhancing their leadership competencies in order to help them be successful. Current leadership development opportunities available to Associate Deans/Chairs are not always well received, and are most effective when they focus on real-life application that addresses the uniqueness and importance of their role. The findings from the study may inform system and institutional policy and practices that would help Ontario college Associate Deans and/or Chairs to be successful, consequently improving the health of the Ontario CAAT system.

Keywords: Associate Dean
Chair
Competency
Leadership
middle-management
Advisor: Dietsche, Peter
Second-order Optimization for Neural Networks

Neural networks are an important class of highly flexible and powerful models inspired by the structure of the brain. They consist of a sequence of interconnected layers, each comprised of basic computational units similar to the gates of a classical circuit. And like circuits, they have the capacity to perform simple computational procedures such as those which might underlie the generating process of the dataset they are trained on. The most popular and successful approach for learning neural networks is to optimize their parameters with respect to some objective function using standard methods for nonlinear optimization. Because basic methods like stochastic gradient descent (SGD) can often be very slow for deeply layered neural networks, or ones with recurrent connections, it is worthwhile to consider more advanced methods. In this thesis we review and analyze various such methods that have been proposed over the past few decades, with a particular focus on approximate-Newton/2nd-order ones, and develop two of our own which we call Hessian-free optimization (HF) and Kronecker-factored Approximate Curvature (K-FAC) respectively. Our experiments show that K-FAC can be much faster in practice at optimizing deep neural networks than well-tuned SGD with momentum.

Keywords: Neural networks
Optimization
Second order methods
Advisor: Zemel, Richard
A Novel Approach for Integrating Best Evidence and Patient Preferences into Treatment Recommendations for Rheumatoid Arthritis

To develop a treatment recommendation we must first critically appraise and summarize the evidence, then decide how to weigh the necessary trade-offs between the benefits and harms. GRADE, which is becoming the standard for developing treatment recommendations, recommends that patients’ preferences should be explicitly considered when making these trade-offs, but methods for doing this quantitatively are lacking. The aim of this thesis was to develop a quantitative approach for combining comparative effectiveness research and patients’ preferences, and apply it to inform treatment recommendations for early rheumatoid arthritis. In the first study, we performed a Bayesian network meta-analysis of 150 randomized controlled trials to compare the benefits and harms of treatment options for early rheumatoid arthritis. In the second paper we used a discrete-choice experiment to measure the relative importance of the major outcomes from the network meta-analysis as well as other issues relevant to the decision (dosing, rare risks) in patients with early rheumatoid arthritis. For the final paper we used a Bayesian framework to combine the data from the network-meta-analysis and the discrete-choice experiment to determine the preferred treatments. Importantly, we modeled the uncertainty in the evidence and patients’ preferences, as well as individual variability in patients' preferences, which are three key considerations in the GRADE approach. Overall, we predicted that most patients in our population (78%) would prefer triple therapy (the combination of methotrexate, sulphasalazine and hydroxychloroquine) to methotrexate alone as initial therapy, suggesting a relatively strong recommendation could be made. In patients who have had an inadequate response to methotrexate, the preferred treatment was more split between triple therapy (62%) and methotrexate + anti-TNF (biologic) therapy. The patients who we predicted would prefer other treatments, had important differences in preferences that could be highlighted in a preference-sensitive treatment algorithm. The thesis therefore presents a novel method for developing evidence-based, preference-sensitive treatment recommendations. Applied to early rheumatoid arthritis, our findings have important policy implications, suggesting that patients would prefer triple therapy to other treatments, including costly biologic therapy.

Keywords: clinical practice guidelines
discrete-choice experiment
network meta-analysis
patient preferences
rheumatoid arthritis
treatment recommendations
Advisor: Bombardier, Claire
Efficient Homotopy Continuation Algorithms with Application to Computational Fluid Dynamics

New homotopy continuation algorithms are developed and applied to a parallel implicit finite-difference Newton-Krylov-Schur external aerodynamic flow solver for the compressible Euler, Navier-Stokes, and Reynolds-averaged Navier-Stokes equations with the Spalart-Allmaras one-equation turbulence model. Many new analysis tools, calculations, and numerical algorithms are presented for the study and design of efficient and robust homotopy continuation algorithms applicable to solving very large and sparse nonlinear systems of equations. Several specific homotopies are presented and studied and a methodology is presented for assessing the suitability of specific homotopies for homotopy continuation.\\ A new class of homotopy continuation algorithms, referred to as monolithic homotopy continuation algorithms, is developed. These algorithms differ from classical predictor-corrector algorithms by combining the predictor and corrector stages into a single update, significantly reducing the amount of computation and avoiding wasted computational effort resulting from over-solving in the corrector phase. The new algorithms are also simpler from a user perspective, with fewer input parameters, which also improves the user's ability to choose effective parameters on the first flow solve attempt. Conditional convergence is proved analytically and studied numerically for the new algorithms. The performance of a fully-implicit monolithic homotopy continuation algorithm is evaluated for several inviscid, laminar, and turbulent flows over NACA 0012 airfoils and ONERA M6 wings. The monolithic algorithm is demonstrated to be more efficient than the predictor-corrector algorithm for all applications investigated. It is also demonstrated to be more efficient than the widely-used pseudo-transient continuation algorithm for all inviscid and laminar cases investigated, and good performance scaling with grid refinement is demonstrated for the inviscid cases. Performance is also demonstrated to be better or comparable to the pseudo-transient continuation algorithm for all turbulent cases investigated. Stability of the new algorithms is also investigated.

Keywords: computational aerodynamics
continuation
globalization
homotopy
predictor-corrector
pseudo-transient continuation
Advisor: Zingg, David W