VictorJuiz/thesis huggingface dataset:
Characterization of Adult Progenitor Cells and their Fate in a Rat Femur Fracture Model

This study was carried out to characterize two progenitor cell populations in the context of orthopaedics and to examining their fate in a rat bone defect model. Endothelial progenitor cells (EPCs) and mesenchymal stem cells (MSCs) isolated from syngeneic bone marrow were characterized utilizing flow cytometry and osteogenic/angiogenic differentiation assays in vitro. To assess in vivo fate, genetically labeled cells were implanted into a defect and examined at two and four weeks post-implantation. Fluorescent microangiography (FMA) was used to model nascent vasculature two weeks post-implantation. The results show populations that resemble established definitions. In vitro, EPCs demonstrated a similar osteogenic capacity to MSCs and superior angiogenic capacity on the basis of tube formation. In vivo experiments showed presence of cells at the fracture site at 2 and 4 weeks. EPCs showed a trend towards increased vessel formation with FMA. These results provide groundwork for future investigation into mechanisms of healing.

Keywords: Fracture Healing
Stem Cell Therapy
Advisor: Schemitsch, Emil H
The Influence of Postsynaptic Structures on Missing Quanta at the Drosophila Neuromuscular Junction

Synaptic transmission requires both pre- and post-synaptic elements for neural communication. The postsynaptic structure contributes to the effectiveness of synaptic currents to induce voltage changes in postsynaptic cells. At the Drosophila neuromuscular junction (NMJ), the poorly understood subsynaptic reticulum (SSR) consists of elaborate membrane folds that link the synaptic contacts to the muscle. I investigate the function of the SSR by conducting electrophysiological experiments on genetic mutants that regulate SSR complexity. I observed that some synaptic currents do not result in postsynaptic voltage changes, events called ‘missing quanta’. Furthermore, the frequency of missing quanta is positively correlated with SSR complexity. Based on cable theory, I propose that the SSR contributes to missing quanta by acting as a filter or a switch for some synaptic events. Further understanding on the role of the SSR in synaptic transmission and ‘missing quanta’ will yield important information about synaptic transmission at the Drosophila NMJ.

Keywords: Drosophila
Electrophysiology
Neuromuscular Junction
Neurophysiology
Synaptic Transmission
Advisor: Stewart, Bryan A
Effect of Solute Concentration Factor (CF) on Ultrafiltration Fouling Mechanism

This study examined the effect of varying the solute concentration factor on the fouling mechanisms, during ultrafiltration (UF) of natural water. Permeation was conducted in two phases: concentration phase and steady-state phase, at different concentration factor (1, 5, and 10). High peak shear, which is representative of large pulse bubble sparging was applied throughout. Results showed that total UF fouling increases with CF during the concentration phase. The dominant fouling mechanism during a cycle is unaffected by increase in CF. For a given CF, standard blocking was dominant during the first cycle of the concentration phase, while combined cake based (i.e. cake-standard and cake-intermediate) blocking during the first cycle of steady-state phase. A fit between measured CF of organic carbon and the predicted values indicated that total and particulate organic carbon (TOC and POC) concentration in the reactor sample correlated with the CF predicted by modeling (R2>0.97).

Advisor: Andrews, Robert C
Berube, Pierre
Examining the Multicultural Experiences of Chinese Graduate Students at the University of Toronto through the Lens of Critical Multiculturalism

This research project investigates Chinese international students multicultural experiences. The existing literature shows that language barrier, cultural adjustment and social support are the major factors that influence international studentsâ life abroad. However, with liberal multiculturalism as the mainstream ideology, multicultural research appears to have a liberal multiculturalism tendency. In this research project, critical multiculturalism is employed as the theoretical framework to avoid the negative impacts from liberal multiculturalism. The study is based on the narratives of four Chinese international students at the University of Toronto. The results of the study show that the lack of recognition of cultural diversity, the evaluation of cultural diversity in a deficit model, failure to show empathy with students from different cultural backgrounds, the assumption of a â samenessâ among international and domestic students, and stress to assimilate into the dominant culture in the public sphere contribute to the pressure faced by international students.

Keywords: critical multiculturalism
international students
multicultural education
multicultural experiences
Advisor: Sumner, Jennifer
Personality Facets in Patients with Major Depressive Disorder: Differential Change across Treatment and Association with Relapse and Recurrence

Personality assessed at a higher-order, “domain” level has shown to be predictive of the treatment response and course of major depressive disorder (MDD). Personality domains have also shown mean-level change (i.e., absolute change) and rank-order stability (i.e., relative stability) across treatment. The nature and prognostic significance of personality change at a lower-order, “facet” level has yet to be evaluated. The present study investigated absolute and relative change of personality facets across cognitive-behavioural therapy (CBT), interpersonal psychotherapy (IPT), and antidepressant medication (ADM) for MDD, and the effect of personality change and pre-treatment personality traits on relapse/recurrence. A total of 150 outpatients with the MDD were randomized to receive either CBT, IPT, or ADM. Remitted patients (n = 92) were assessed on a weekly basis for a maximum of 18 months following treatment. Findings support absolute change and relative stability of personality facets, indicating that both components of personality have prognostic significance.

Keywords: Antidepressant Medication
Cognitive-Behavioural Therapy
Depression
Five-Factor Model
Interpersonal Psychotherapy
Personality Facets
Advisor: Bagby, R. Michael
Quilty, Lena C
Changes in Neural Systems Underlying Response Inhibition in Patients with BPD After Six Months of Dialectical Behaviour Therapy

Borderline Personality Disorder (BPD) is a highly prevalent mental disorder, characterized by impulsive behavior (e.g., self-harm). However, the neural basis of treatment-related change in BPD is yet to be fully explored. The present study examined the neural correlates of inhibitory control within the prefrontal cortex (PFC) in 29 self-harming patients with BPD who underwent approximately six-months of Dialectical Behavior Therapy (DBT). Pre-treatment, patients demonstrated lower activation bilaterally and higher activation medially in the PFC. After approximately six-months of DBT, patients demonstrated higher activation in the bilateral regions of the PFC and also in the right medial PFC. These activation patterns were also associated with improvements in BPD symptom domains. Additionally, differences in patterns of activation in patients who completed six months of treatment versus those who dropped out or did not initiate treatment were also explored. These findings provide insight into neural mechanisms underlying treatment-related symptom change in BPD.

Keywords: Borderline Personality Disorder
Dialectical Behavior Therapy
Functional Near-Infrared Spectroscopy
Prefrontal Cortex
Response Inhibition
Self-Harm
Advisor: Ruocco, Anthony C
Tea, Toast and Red Lipstick: Understanding Perceptions of Food, Body Image and Age in Older Women

Though life history methodology, I explore the question: what do the life histories of older women reveal about how lived experience influences perceptions of food, body image and age? The purpose of this research is to develop a deeper understanding of food, body image and age, as it relates to women over 70 years of age; a context infrequently explored in this generation of women and therefore, underrepresented in the literature. It also facilitates a healing process for my personal struggles. In committing to the defining elements of life history research, the stories of Sam and Lina are explored with intentionality, reflexive writing, holistic quality, communicability, aesthetic form and with respect and appreciation for the knowledge life history brings to our broader social context (Cole Knowles, 2001). Themes, such as family relationships, peer influence, life achievements financial stability and the effects of a decline in health are explored.

Keywords: age
body image
food
life history
older adults
women
Advisor: Knowles, Gary
Outcrop Based Facies and Architecture Analysis of the Regional Intertonguing of Early Jurassic Kayenta Formation with the Navajo Sandstone, Kanab Canyon, Utah

The establishment of the extensive Navajo erg can be identified in the Lower Jurassic rocks of the Kanab Canyon area by three distinct and successively thicker advances over the marginal fluvial Kayenta. A total of 15 fluvial and eolian facies were identified based on several vertical sedimentological logs. The facies were summarized in four main facies associations, representing multistorey braided fluvial channels, unconfined ephemeral fluvial sandsheets, erg margin and eolian dune depositional settings. The eolian units have a consistent paleoflow towards the east, which opposed the fluvial paleoflow towards the west. Fluvial architectural element analysis was completed in four lateral outcrop profiles. Additionally, two lateral architectural profiles were completed within the eolian units. Based on systematic vertical facies association transition and overall decrease in fluvial energy upsection, three drying-up trends were identified. These trends are proposed to be correlative across the basin and likely represent climatic cycles.

Keywords: Eolian sedimentology
Fluvial sedimentology
Utah
Advisor: Miall, Andrew
DEVELOPING A TEXT MESSAGING INTERVENTION TO SUPPORT MEDICATION ADHERENCE TO ENDOCRINE THERAPY IN ADJUVANT BREAST CANCER: AN INTERPRETIVE DESCRIPTION APPROACH

Most adjuvant breast cancer patients are prescribed long-term endocrine therapy; however, not all patients continue these medications long term. Text messaging programs have been shown to be a low cost means of increasing medication adherence in a wide variety of chronic conditions, but have not been extensively studied in the breast cancer setting. The primary objective of this study was to develop a text messaging intervention to support long term endocrine therapy adherence. First, we sought to understand the breast cancer survivorship experience in the context of endocrine therapy. Second, we were interested in womenâ s experiences when using a theoretically grounded text messaging intervention. Participants were recruited from a single large academic centre. The initial text messaging intervention was informed by the Medication Adherence Model. Data collection comprised of two semi- structured interviews with eight participants, as well as enrollment in the text messaging intervention. Two main themes arose regarding the experience of breast cancer survivorship. First, fear of recurrence and the worry about returning to normal after breast cancer treatment were dominating emotional experiences. As a result, a high degree of uncertainty permeated their lives, and learning to manage uncertainty was identified as a critical coping skill. When participants were asked regarding preferences for a text messaging intervention, women stated they were interested in an intervention that would act as a supporting friend, sending positive messages about overall wellness. In addition, message tailoring was recognized as an important characteristic in order to increase program usefulness. These findings are useful in shaping future work ensuring long term medication adherence to endocrine therapy.

Keywords: breast cancer
endocrine therapy
intervention development
mHealth
text messaging
Advisor: DeAngelis, Carlo
Association of Alcohol Consumption with Glucose Homeostasis: A Systematic Review and Meta-analysis

Impaired glucose homeostasis is associated with increased risk of type 2 diabetes and cardiovascular diseases. Therefore, having in-depth knowledge about different risk factors involved in the pathogenesis of impaired glucose homeostasis is necessary. No systematic review has evaluated observational studies for the long-term effects of alcohol consumption on glucose homeostasis. We aimed to conduct a systematic review and meta-analysis to assess the association of alcohol consumption with different parameters of glucose homeostasis. Medline and Embase were searched for cohort and case-control studies about association of alcohol consumption with glucose homeostasis parameters. Identified articles with the outcome of impaired fasting glucose (IFG) were quantitatively summarized in a meta-analysis. Our study suggests an overall increase in the incidence of IFG in association with alcohol consumption. For other indicators of glucose homeostasis (e.g. serum insulin and HbA1C), the number of included studies were low and the results were inconsistent

Advisor: Rehm, Jurgen
Characterization and Modification of the Zinc Sensor ZapCY2 for Improved Nickel Binding

Nickel is an important element needed for the function of many microorganisms, including several strains of pathogenic bacteria such as Escherichia coli and Helicobacter pylori. The free intracellular nickel concentration has not been quantified for any microorganism, and such information would be very beneficial for understanding the biochemistry of pathogenic bacteria. This research aims to develop an intracellular FRET-based nickel sensor for this purpose. A previously designed zinc sensor, ZapCY2, was selected to undergo characterization and modification in an effort to tune its selectivity to favor nickel. Cysteines in the metal-binding sites were substituted with histidine or aspartic acid. Characterization of the variants revealed a 15-30 fold reduction in the affinity for zinc, and an unchanged affinity for nickel. Additional modifications will be required to further improve the sensorâ s response towards nickel.

Keywords: Bacteria
FRET
Nickel
Protein
Sensor
Advisor: Zamble, Deborah B
Application of High-order Summation-by-parts Operators to the Steady Reynolds-averaged Navier-Stokes Equations

Third- and fourth-order methods have been implemented to solve the steady Reynolds-averaged Navier-Stokes equations with the Spalart-Allmaras turbulence model. Summation-by-parts operators are used for spatial discretization along with simultaneous approximation terms to enforce boundary and interface conditions in a weak sense. Two validation cases are tested to verify the high-order implementation of the turbulence model and to examine the efficiency and robustness of the high-order methods. It is shown that the third-order method generally produces the most accurate results on a given mesh. The use of the fourth-order method also shows the potential of increasing numerical accuracy over the second-order method on coarse meshes. In terms of computational cost, the results demonstrate that the high-order methods are more efficient as the same level of accuracy can be achieved within less computational time on a coarser mesh.

Keywords: High-Order Methods
Turbulence Modelling
Advisor: Zingg, David W
Body Composition of Infants with Gastroschisis Assessed by Air Displacement Plethysmography

Background: Measuring body composition (BC) in infants enables monitoring their growth pattern. Air displacement plethysmography (ADP), a BC technique that is practical for infants, but has not been adequately assessed in different infant populations. Objective: To demonstrate the suitability of the ADP in a high-risk population and to evaluate their BC. Methodology: The study was observational; subjects were recruited from the Hospital for Sick Children. A total of 12 Infants â Ľ 33 weeks corrected gestational age at birth, diagnosed with gastroschisis, were studied. BC was measured post-surgery and a month thereafter. Results: fat mass (FM) did not show a significant difference in our study group compared to healthy infants at both measurements. However, fat free mass (FFM) was significantly lower in our study group than healthy infants at both measurements. Conclusion: There were no procedure-related complications. A smaller gain in FFM than expected was shown in this group of patients.

Keywords: Air Displacement Plethysmography
Body Composition
Gastroschisis
Infants
Nutrition
Pediatrics
Advisor: Tomlinson, Christopher
Pencharz, Paul
A Design Framework for Collective Inquiry Learning Environments

This thesis describes a design-based research study of a recent KCI implementation in a whole-class inquiry elementary science curriculum called WallCology, focusing on the interaction design aspects of its technological support. From that, the thesis builds a framework for HCI design for the specific context of Knowledge Community and Inquiry (KCI), a CSCL model that guides the design of collective inquiry curriculum in which students work together to advance their collective progress on a set of well defined learning goals. This design framework comprises a series of conceptual design principles, guidelines for implementing a visual language for interface design, and an ontology of human-computer interactions that could emerge in a KCI enactment, with examples of GUI design solutions to support them.

Keywords: Collective Inquiry
Computer-Supported Collaborative Learning
Educational Technology
Human-Computer Interactions
Interaction Design
Technology-Enhanced Learning
Advisor: Slotta, James D
Simvastatin Prevents and Reverses Chronic Pulmonary Hypertension in Newborn Rats via Pleiotropic Inhibition of RhoA Signaling

Chronic neonatal pulmonary hypertension (PHT) frequently results in early death. Systemically administered Rho-kinase (ROCK) inhibitors prevent and reverse chronic PHT in neonatal rats, but with side effects including systemic hypotension and growth restriction. Simvastatin has pleiotropic inhibitory effects on isoprenoids that may limit activity of RhoA, which signals ROCK. We examined the preventive and rescue effects of simvastatin on chronic hypoxia-mediated chronic PHT. Newborn rats were exposed to normoxia (room air) or moderate hypoxia (13% O2) from postnatal day 1 and received simvastatin (2 mg/kg/day i.p.) from postnatal days 1-14 (prevention) or from postnatal days 14-21 (rescue). Simvastatin decreased RhoA/ROCK signaling in the hypoxiaexposed lung. Treatment of chronic hypoxia-exposed animals with simvastatin decreased pulmonary vascular resistance, right ventricular hypertrophy, and pulmonary arterial remodeling. We conclude that simvastatin limits RhoA/ROCK activity in the chronic hypoxia-exposed lung, thus ameliorating hemodynamic and structural markers of chronic PHT, without causing adverse systemic effects.

Keywords: Echocardiography
Newborn
Pleiotropic
Pulmonary Hypertension
ROCK/RhoA
Statins
Advisor: Jankov, Robert P
Effects of Concurrent Exposure of Diesel Exhaust Particles and House Dust Mite on the Development of Allergen-Induced Airways Inflammation

Chronic air pollution exposure is associated with accelerated lung function decline and increased prevalence and exacerbations of chronic inflammatory lung diseases, such as asthma. However, its pathological effects have not been studied extensively. Therefore we assessed the physiological and immune responses induced by chronic exposure to low concentrations of diesel particles (freshly-generated particles [DEP] or diesel standard reference material [SRM]) in both healthy mice and those with house dust mite (HDM)-induced allergic airways inflammation (reflective of asthma). We found that SRM exposure led to subtle neutrophilic inflammation in healthy mice, and that DEP increased central airway reactivity without affecting resultant airway constriction to methacholine in the asthma model. Results suggest that chronic exposure leads to immune changes in mice representing healthy individuals that may enhance the adverse effects of future allergen encounter; the low dose of particulate matter exposure has no effect in asthmatic background.

Keywords: allergen
asthma
particulate matter
pollution
Advisor: Chow, Chung-wai
The Influence of Selective Attention on Auditory Localization in Younger and Older Adults

Auditory localization, the ability to locate sounds, declines with age due to changes in peripheral and central auditory processing. As selective attention is typically preserved in older adults, drawing their attention towards the stimulus before it occurs may improve auditory localization. This study evaluated this hypothesis by precueing younger and older participants towards a likely location of the upcoming target (a broadband noise) with a visual attentional cue. The attentional cues either provided a) correct information about the upcoming target location (valid) b) incorrect information about the upcoming target location (invalid), or c) no information about the upcoming target location (neutral). Participants estimated the targetâ s location on a schematic drawing of the testing environment. Akin to younger adults, older adults made less errors and biases, and faster responses with valid cues. This suggests that older adults can employ selective attention to improve auditory localization, similar to younger adults.

Keywords: aging
Auditory localization
cognition
perception
Selective attention
spatial perception
Advisor: Campos, Jennifer
Spence, Ian
Non-Invasive Methods of Human Embryo Quality Assessment: Exploring Morphokinetic, Metabolomic and Secretome Parameters That Predict Pregnancy Outcome in IVF

In-vitro fertilization (IVF) is a commonly used infertility treatment involving fertilization of the oocyte by sperm outside of the body. Morphological assessment is the primary non-invasive criteria used to select embryos for uterine transfer, however, using this method, the current success rate is around 30%. Thus, more non-invasive tools are needed to improve the process of embryo selection. The objective of this thesis is to explore and assess additional non-invasive methods, including morphokinetics, metabolic profiling and extracellular vesicle release, as biomarkers for selecting the embryo with the highest implantation potential. Results show some morphokinetic parameters are correlated with implantation and metabolomic analysis can provide further insight in understanding embryo physiology. Moreover, we show for the first time, the possibility of the release of extracellular vesicles from human pre-implantation embryos. This data provides validation that these techniques have the potential to be brought into routine clinical use for embryo selection.

Keywords: Embryo Selection
Extracellular Vesicles
Human
IVF
Metabolomics
Morphokinetics
Advisor: Librach, Clifford Lawrence