VictorJuiz/thesis huggingface dataset:
Weighing In: Psychological outcomes associated with weight changes among women treated for breast cancer

This mixed-methods program of research consisted of three inter-related studies to examine how changes in weight contribute to womenâ s psychological health in the post-treatment phase of breast cancer. Study 1 employed a qualitative design and purposeful sample of weight-preoccupied women (n = 11), to explore experiences of weight-related changes post-treatment, and examines perceptions of weight throughout the cancer trajectory. In a prospective longitudinal design spanning the first-year post-treatment for breast cancer (n = 173), Study 2 examines how pre-cancer and post-treatment weight patterns impact indices of psychological health (i.e., weight-related guilt, shame, and depressive symptoms). Study 3 utilized a daily diary design of women with comorbid breast cancer and obesity (n = 52) to assess the acute emotional outcomes associated with daily self-weighing in the context of weight management. Collectively, this body of work underscored the distressing nature of both weight changes and weight management efforts, in the context of reducing risk for breast cancer. Women reported experiencing more negative emotional consequences when their weight was higher than usual, both acutely after self-weighing and chronically over time in the first-year post-treatment. It was further suggested that a history of pre-cancer weight cycling served as an additional risk factor predicting worsened psychological experiences after treatment. These findings are important given that the well-documented impact of excess weight and psychological distress on worsened cancer survival. In light of the fundamental challenges of weight management, targeting womenâ s weight-related psychological distress after breast cancer should be a clinical priority. Recent weight-neutral paradigms and compassion-focused approaches may be useful for improving the psychological health and well-being of women across the weight spectrum, and throughout the cancer trajectory.

Keywords: body image
breast cancer
obesity
weight
women's health
Advisor: Sabiston, Catherine M
On the Launching of Optically Thick Outflows from Massive Stars

For decades, massive stars have been seen to lose mass at every stage of evolution. In recent years, detections of outbursts and circumstellar relics uncover transient modes emerging moments before the supernova. The goal of this thesis is to bring theoretical attention into how massive stars launch outflows. In this thesis, we study two modes of mass loss seen during rare, but critical, phases of stellar evolution. The first considers dense, steady outflows from Wolf-Rayet stars. The second considers the eruptions and explosions seen from luminous blue variables (LBVs) and Type IIn supernova (SN) progenitors. Outflows from both systems are optically thick but either radiative or adiabatic in nature. Wolf-Rayet winds are driven by strong radiative pressure on metal lines. Suppressing the outflow is shown to drastically alter the stellar structure with peculiar features including an extended radiative cavity encased in a massive shell. We construct outflow models and conclude the galactic WR population does not harbour such structures. We derive a minimum mass loss rate to launch a transonic, optically thick outflow and find the iron opacity bump to be responsible for launching WR winds. LBVs and Type IIn SN progenitors are seen to abruptly expel mass. Observational inferences suggest the rates are both exceptional and unsustainable with durations exceeding the outer envelope dynamical time. Yet, these outflows are occasionally preceded by fast motions indicative of shock acceleration. In this thesis, we explain how waves can be responsible for these dynamics. We derive an analytic solution wave steepening and shock formation for an inhomogeneous medium. The results suggest that any super-Eddington phenomenon driven by waves \textit{must} involve shocks. Shocks form deep in the star where they are initially weak. We show how weak shocks are capable of accelerating to become strong, breakout, and produce fast ejecta using a revived semi-analytical approximation. We discuss how a train of shocks can heat a large volume of the envelope and eject significant mass.

Keywords: Acoustic waves
hydrodynamics
Massive Stars
Shocks
supernova
Winds
Advisor: Matzner, Christopher D
Fatty acid composition in four serum lipid fractions and the pathogenesis of diabetes

Type 2 diabetes mellitus (T2DM) is a chronic disease of glucose dysregulation leading to elevated blood glucose. Given that fatty acid and glucose metabolism are tightly entwined and that limited long-term data are available on this relationship, the objective of this thesis is to investigate the longitudinal associations of fatty acids from four lipid fractions on insulin sensitivity and beta-cell function. Data from an observational cohort of adults at risk for T2DM (n=477) was used, where 22 fatty acids in phospholipid, cholesteryl ester, triacylglycerol (TAG), and non-esterified fatty acid (NEFA) fractions were quantified. Insulin sensitivity and beta-cell function indices were computed using glucose and insulin obtained from a 75g oral glucose tolerance test. Results from the analyses of these data show that fatty acids have differential associations with the pathogenesis of T2DM, dependent on the lipid fraction and on the species. Fatty acids within either phospholipid or TAG fractions showed varied and strong associations with insulin sensitivity and moderate associations with beta-cell function, while few associations were seen in the cholesteryl ester or NEFA fraction. Some results of particular note: higher phospholipid palmitic acid associated with 6-year declines in beta-cell function; phospholipid and TAG cis-vaccenic acid had consistent and strong beneficial associations with insulin sensitivity and beta-cell function; four TAG fatty acids strongly clustered together and higher levels strongly associated with lower insulin sensitivity, of which these four fatty acids are also indicative of higher de novo lipogenesis; and, higher total NEFA concentration associated with lower beta-cell function, independent of the specific fatty acid composition. These results emphasize that fatty acids have complex and differential associations on glucose metabolism and highlight potential areas of future research, for instance, on the de novo lipogenesis fatty acids or with cis-vaccenic acid, the study of which may lead to better prevention or management strategies for T2DM.

Keywords: Beta-cell function
Diabetes
Fatty acid composition
Insulin sensitivity
Longitudinal cohort
Advisor: Hanley, Anthony
Bazinet, Richard
Addressing Complexities in Early Childhood Education and Care: The Relationships among Paradigms, Policies, and Children's Rights to Participate

This dissertation contributes to the field of Early Childhood Education and Care studies by providing the in-depth theoretical, document, and empirical analyses. The three types of analysis aim to build a case for the practical utilization of the critical paradigm. The critical paradigm is understood as a driving force for early childhood pedagogy which empowers educators, policy-makers, and academic scholars to apply a practical change in the field while acknowledging and sustaining the young childrenâ s right to actively participate in matters related to their education and well-being. In this venue, the thesis provides (i) a thorough and productive analysis of the paradigmatic discussions presently available in the field of early childhood education; (ii) an argument for the practical application of the critical paradigm; (iii) an application of the paradigmatic debates to early childhood curricular and policy documents; (iv) and an empirical evidence from the field which has not been documented before and which gives insights to changes needed in policy directions and the preparation of pre-service early childhood educators.

Keywords: child as an active agent
children as active citizens
early childhood education care
ECE: consulting with young children from 0-8
image of the child
participatory rights of children
Advisor: Portelli, John Peter
The Examination of Different Pathways Leading Towards Police Traumatization: Exploring the Role of Moral Injury and Personality in Police Compassion Fatigue

Abstract Police officers are mandated to respond to critical incidents, and, as the first responders to arrive at a crime scene, they are often tasked with providing support to traumatized victims of crimes. Compassion fatigue is a type of traumatization (“cost of caring”) experienced by caregiving professionals who work with traumatized populations (Figley, 1995). Conversely, compassion satisfaction refers to the sense of fulfillment that first responders feel from helping those who suffer (Stamm, 2002). The current research project is comprised of three studies. In study 1, researchers recruited a national police sample (n=1,351) from the US and Canada and measured the prevalence rates of compassion fatigue and satisfaction. This study found that authoritarianism was significantly associated with compassion fatigue among study participants. In study 2, the researcher further explored the role of negative personality traits (i.e., dark triad—Machiavellianism, narcissism, psychopathy) in a national sample (n=1,173) of police officers serving with the National Police of Finland. Study 2’s findings were consistent with those of Study 1, showing that negative personality traits were significantly associated with compassion fatigue among police officers. Study 3 built on the main findings of the first two studies, and aimed to identify the different pathways that lead to traumatization by examining moral injury’s role in the process. Moral injury refers to unprecedented traumatic life events, which can be understood as events wherein one perpetrates, fails to prevent, or bears witness to actions that “transgress deeply held moral beliefs and expectations” (Litz et al., 2009, p.1). Employing moral injury would enable researchers to examine the different mechanisms that lead to traumatization. To this end, study 3 recruited a sample (n=453) comprised of officers from the National Police of Finland, and the results showed that the dark triad of personality traits significantly predicted “self-focused” and “others-focused” moral injury. In addition, “self-focused” moral injury (and not “others-focused” moral injury) significantly predicted compassion fatigue and PTSD symptoms. Furthermore, it was found that “self-focused” moral injury significantly mediated the pathway between the dark triad personality traits and traumatization (compassion fatigue and PTSD symptoms). Clinical implications and recommendations for future research are discussed.

Keywords: compassion fatigue
compassion satisfaction
moral injury
negative personality traits
police
traumatization
Advisor: Andersen, Judith
Building Learning Community in Post-Secondary Large Lecture Courses: A Blended Approach to Fostering Communities of Learners

This design-based research study examined the ways in which a learning community approach can be enacted in large undergraduate lecture courses through a scaffolded, complex curricular design that utilizes active and inquiry-based learning. By combining a traditional lecture with breakout tutorials, the study involved two iterations, firstly by adopting the Fostering Communities of Learners (FCL) pedagogical model (Brown Campione, 1996) then by augmenting the model by blending its methodology with elements from the Knowledge Community and Inquiry (KCI) model (Slotta Peters, 2008; Slotta Najafi, 2010). The first iteration ( N = 236) consisted of a twelve week course, combining lectures with 12 breakout tutorial sections (N = 20). The course addressed a variety of foundational business concepts for undergraduate media students. The second iteration (N = 231), conducted the following year, included a digital Collaborative Knowledge Base (CKB) which was populated by student inquiry exercises and served to coordinate or index their subsequent inquiry activities. Both iterations were evaluated for adherence to, and enactment of, the FCL principles. The second iteration was further evaluated for adherence to the newly introduced KCI-inspired CKB, which measures included the enactment of the curricular design, achievement of course learning outcomes, the group inquiry project, tutorial activities, pre- and post-term surveys and focus groups for TAs and students. Findings provided evidence of the viability and effectiveness of a learning community approach in large lecture courses at the undergraduate level when combining FCL learning principles with a student-populated dynamic knowledge base. Students achieved both individual and group success in meeting learning outcomes through individual inquiry and collaborative, active learning, with the CKB providing a forum for students to share their research and access ideas for their inquiry. It also served as a nexus, connecting lectures and tutorials with community content, thereby encouraging a class-wide learning community. This dissertation outlines a promising source of evidence and guidelines for instructors who seek to adopt a learning community approach for large lecture courses. It adds to the existing body of research on learning communities and makes connections to emerging areas of active learning for higher education.

Keywords: active learning
collaborative learning
inquiry learning
learning community
social constructivism
Advisor: Slotta, James D
Dielectrophoresis microdevice design for selective lysis of circulating tumor cells in blood

Cancer is a leading cause of death in industrialized nations. A major contributor to the lethality of cancer lies in its ability to undergo metastasis, a process in which cancer spreads from its originating site to other locations in a patientâ s body. One of the pathways that cancer spreads is through a patientâ s bloodstream. Circulating tumor cells (CTCs) detach from tumors and enter blood vessels. Studies have shown that patients with high numbers of CTCs have lower survival probabilities than cancer patients with low CTC counts. We hypothesize that it may be possible to reduce the risk of metastatic disease in cancer patients by removing CTCs from the bloodstream. To this end, this thesis investigates the design of a microfluidic device capable of isolating and destroying cancer cells mixed with blood cells. This work acts as a first step and proof-of-concept towards the development of a therapeutic platform to filter CTCs from patient blood. Dielectrophoresis (DEP), a contact-free, electrode-based cell manipulation technique is used to spatially separate CTC analogue cells (MCF7 breast cancer cells) from blood cells. Larger cancer cells experience a greater DEP force and, therefore, levitate higher than smaller blood cells. Cancer cells are lysed using irreversible electroporation, an electrode-based technique that uses high magnitude electric fields to permanently open cell membranes. Cancer cells are levitated via DEP into proximity of electroporation electrodes to localize the lysis effect in the prototype device. Localized lysis of cancer cells is demonstrated through experiments with a fabricated prototype device. A novel electrode optimization protocol was developed to aid in the design of dielectrophoresis electrodes used in cell separation. To generate new electrode geometries, electrodes are designed in a pixel-based manner using a genetic solver. Optimal electrodes obtained through this protocol are fabricated in University of Toronto cleanrooms and used in experiments. Additionally, due to the stated design goal of separating CTCs from blood cells, thrombogenesis (blood clot formation) due to DEP-based cell separation is investigated. Experiments reveal that dielectrophoresis has a suppressive effect on blood clot formation, a finding that may be extended to applications requiring clot suppression beyond the device proposed in this thesis.

Keywords: Circulating Tumor Cell
Dielectrophoresis
Electroporation
Genetic Optimization
Microfluidics
Thrombogenesis
Advisor: Mills, James K.
The Effects of Transmediation on Students' Creativity Through Collaborative Composing

The purpose of this action research was to investigate the process and the effect of the transmediation (translation of content from one media to another) on students’ creativity. The goal was achieved by focusing on: (a) students’ collaborative strategies of translating non-musical sources to musical compositions; (b) the effects of the level of abstraction of the sources on students’ creative processes and products; and (c) the effects of transmediation on students’ general and domain-specific creativity compared to the general music classes. This study was conducted in a Grade 8 beginner strings’ class of thirteen students. The study was divided into two phases: the teacher taught six classes, then the students were divided into groups of four or five to compose musical pieces through transmediating the given source. Six classes were spent translating verbal, visual, and video sources, with each mode containing one direct and one abstract source. Students were tested three times throughout the study (before and after phase 1, and after phase 2) with two tests on musical and general creativity. The results revealed that students were able to use multiple modes of communication effectively to face the challenge of transmediation: verbal expression to describe and give precise directions; musical sound to demonstrate musical ideas; and gestures to point, demonstrate, and express rejection or acceptance of ideas. Second, when students were working with more abstract sources, the number of interactions significantly increased, and the products demonstrated more complex levels of transmediation. Third, the increase of the test scores was significantly greater after the transmediation unit, suggesting that it had greater positive effects on students’ creativity than the general music classes. Overall, the findings suggest that the right level of transmediation task is effective in fostering students’ domain-specific and general creativity.

Keywords: 21st century skills
collaborative composing
creativity
multiliteracies
music education
transmediation
Advisor: Bartel, Lee
PERSPECTIVES IN ADAPTIVE COPING: THE RETRAINING EXPERIENCES OF IMMIGRANT PROFESSIONALS IN CANADA

This study examined the retraining experiences of immigrant professionalâ s in Canada. Using a qualitative research methodology, specifically a constructivist grounded theory approach, the individual narratives of 20 highly educated and professionally seasoned immigrant professionals were explored. In an effort to optimize life-career success, all of the participants completed formal retraining in Canada. Therefore, the results of this study are especially relevant to the broader context of immigrant professionals retraining experiences in Canada. The majority of immigration literature to date has focused on the challenges and barriers of life-career transition. This study aimed to expand present literature through the empirical investigation of the positive side of immigration. Namely, the personal, subjective accounts of the psychological, behavioural, and contextual ingredients of successful life-career transition were explored. To do so, a semi-structured interview format was employed to elicit from participants the individual and contextual processes that facilitated adaptive coping in response to the well-documented challenges and barriers of transition. The results of this study revealed that life-career outcome, within the broader retraining context, is largely mediated by several individual and contextual factors of influence. The research proposes the adaptive coping model of immigrant life-career transition. The model highlights that life-career outcomes involve dynamic and reciprocal interactions between the individually based constructs of agency and resilience, and psychological and action-oriented coping behaviours with several contextually driven supports and resources. The theoretical and practical implications, and the limitations of the study are discussed, and recommendations for future research are proposed.

Advisor: Chen, Charles
Structural and Functional Characterization of RAF Allosteric Regulation

The RAS-ERK/MAPK pathway is a critical signalling pathway regulating cell growth, proliferation, and survival. As such, aberrant signalling through this pathway is often associated with tumourigenesis. At the apex of the ERK/MARK pathway are the RAF kinases, a family of Ser/Thr kinases that initiate the phosphorylation cascade following pathway activation. Consequently, RAF kinases are often mutated or dysregulated in cancers, especially malignant melanomas where RAF is mutated in ~70% of cases (Dhomen and Marais 2007). While all five members of the RAF kinase family have been implicated in cancer, over 90% of all RAF-related tumours are due to mutation of BRAF alone (Forbes et al. 2011). In addition to activation by interaction with upstream signalling components, most notably RAS, RAF kinase activity is regulated through dimerization of its kinase domain (Rajakulendran et al. 2009). Although structures of RAF dimers reveal the kinase-active conformation, how dimerization allosterically activates RAF remains unknown due to an absence of kinase-inactive RAF structures as a basis for comparison, precluding a full picture for how cancer-related RAF mutants lead to aberrant kinase activity. Importantly, a poor understanding of the nuances that govern RAF activation has clinical consequences, as RAF inhibitors used in the clinic can unexpectedly promote RAF activity and lead to exacerbation of tumourigenesis through unclear mechanisms (Hatzivassiliou et al. 2010; Poulikakos et al. 2010; Heidorn et al. 2010). The work described in this thesis was conducted with the aim of: (1) determining the structural basis for how kinase dimerization promotes RAF activity; (2) understanding how cancer-related RAF mutations promote kinase activity; and, (3) identifying inhibitors that avoid unexpected activation of RAF in cells. In Chapter 1, I provide relevant background on RAF signalling. In Chapter 2, I present the crystal structure of a dimer-promoting ATP-competitive inhibitor in complex with RAF and, in collaboration with others, I present a model for how inhibitors promote RAF dimerization through stabilization of a rigid, closed, conformation of the kinase domain. In Chapter 3, I present the crystal structure of BRAF in complex with a monomer-inducing ATP-competitive inhibitor and validate the structure as being reflective of the native RAF kinase-inactive conformation. Importantly, the structure and accompanying biochemistry provide formal proof for an allosteric link between the RAF dimer interface, the kinase activation segment, and the catalytic infrastructure housing the ATP binding site. Together this work establishes the structural basis for how RAF is regulated through dimerization and reveals the chemical features of inhibitors that limit paradoxical RAF activation. Lastly, in chapter 4, I discuss future avenues in RAF research.

Keywords: cancer
kinase
oncology
RAF
Advisor: Sicheri, Frank