VictorJuiz/thesis huggingface dataset:
What's "Quickest and Easiest?" Parental Perspectives of the Trip To and From School

This study examined perspectives of the trip to/from school and travel mode choice among parents who differed in socio-economic status (SES), and whose children attended schools located in different areas (i.e., urban vs. inner-suburban) across Toronto. Thirty-seven parents (20 active and 17 non-active travelers) of grade four to six students from four elementary schools (capturing diversity with respect to built environment and SES) participated in qualitative interviews after taking photos of their trip to/from school. Data were analyzed using thematic analysis linking the text and visual data. School travel was a habitual behaviour involving a 2-step parental decision-making process; these decisions were influenced by different factors. While escort decisions were dictated by safety concerns, the behavioural cost and reinforcing value of travel mode alternatives dictated mode choice. Strategies addressing these behavioural cost and reinforcing value factors may be helpful in making walking to/from school the quickest and most convenient choice.

Keywords: Active School Transport
Advisor: Faulkner, Guy
Women’s Cricket Spaces: An Examination of Female Players’ Experiences in Canada

Presently the literature available on women’s cricket is very limited. This thesis attempts to redress this gap by telling a story about the experiences of women’s club cricket in Toronto and Victoria. The player’s social spaces were examined, as were the intersections of gender, race and culture.. Using qualitative methods, narratives were interpreted and analyzed using post-colonial, spatial and feminist theoretical frameworks. Major findings indicated that there are specific challenges to women’s participation in cricket in Canada and revealed differences between players due to geography, access to resources, ethnicity and race. Women also experienced inclusions and exclusions based on gendered reproductions. The results indicate that much more support is needed for women’s cricket to flourish in Canada. One strong recommendation this study makes is that we pay more attention to, and develop better strategies for, the integration of Canadian immigrant and racialized women into the Canadian sport and recreation system.

Keywords: women's
cricket
sport
Canada
gender
experiences
racialized
space
race
Advisor: MacNeill, Margaret
Fusco, Caroline
Finite Element Modeling of Extensor Carpi Radialis Longus and Brevis: Computation of Architectural Parameters and Physiological Cross Sectional Area as Whole Muscles and Regions

Physiological cross sectional area (PCSA) is used to compare force-producing capabilities of skeletal muscles. PCSA has been defined as the summation of the cross sectional area of the fiber bundles composing the muscle. As PCSA cannot be measured directly from a specimen, a formula requiring averaged muscle architectural parameters has traditionally been used. The purpose of this study was to develop a finite element method (FEM) to calculate PCSA of extensor carpi radialis longus (ECRL) and brevis (ECRB) directly from digitized fiber bundle data obtained throughout the volume of the muscle and to compare the PCSAs calculated using the FEM and formula methods. Differences were found between the FEM and formula method for both muscles. The FEM provides an approach that takes into account architectural variances while minimizing the need for averaged architectural parameters.

Keywords: computer modeling
muscle architecture
physiological cross sectional area
fiber bundle length
pennation angle
muscle volume
finite element modeling
skeletal muscles
ECRL
ECRB
biomechanics
computer graphics
3D modeling
anatomy
Advisor: Agur, Anne M. R.
McKee, Nancy
General Base Catalyzed Deprotonation of a Thiamin-derived Intermediate: Evidence for Sequential Proton Transfer in Pyridine Catalyzed Decarboxylation

The conjugate acid of pyridine had been found to catalyze decarboxylation of alpha-mandelylthiamin (MTh). It was proposed this occurs by association between the substrate and pyridinium ion in a pi-stacked complex prior to cleavage of the C-C bond. Despite the evidence for selective acid catalyzed decarboxylation of MTh with pyridine and its derivatives, the nature of proton transfer occuring after the C-C bond breaks and before the final products form had not been investigated. General base catalyzed deprotonation of hydroxybenzylthiamin (HBnTh) has been applied as a model for the reverse reaction of acid-catalyzed decarboxylation. Kinetic analysis of this process suggests the acceleration by a preassociated pyridinium ion and the product-determining step in the decarboxylation of MTh are facilitated by independent sequential proton transfers.

Keywords: Thiamin
decarboxylation
Advisor: Kluger, Ronald
Clone History Shapes the Populus Drought Transcriptome

The genus Populus is ideally suited to investigate questions related to the interplay between an individual’s environmental history and its capacity to respond to external stimuli. In order to dissect the influence of individual history on subsequent plant responses, transcriptome level changes due to water deficit were assessed in clonal populations of Populus hybrids. Results indicate variation in the drought transcriptomes of genetically identical clones originating from different locations can be shaped by the individual history of the clone. Additionally, yearly variations in drought transcriptome patterns showed specific trends associated with a clonal population that were not related to an unknown influence at a location, nor with the biological source of cuttings. Despite these sources of transcriptome variation, a common shared response was identified across all populations. The findings hint at the influence of the environment and epigenetic factors in the dynamic regulation of transcriptome level responses in clonal individuals.

Keywords: clone
clonal populations
clonal variation
transcriptome
gene expression
microarray
genomics
transcriptomics
plants
trees
water relations
drought
clonal differences
epigenetics
somatic mutations
somaclonal variation
clonal variation
genetically identical individuals
intra-individual variation
Advisor: Campbell, Malcolm M.
Calcium Regulates Cyclic Compression-induced Early Changes In Chondrocytes During In Vitro Tissue Formation

A single application of cyclic compression to bioengineered cartilage improves tissue formation through cell shape changes that are mediated by α5β1 integrin and membrane-type metalloprotease (MT1-MMP). To determine if this response is controlled by calcium, we investigated how calcium regulated cell shape changes, MT1-MMP and integrin activity in response to stimulation. Stimulation-induced changes in cell shape and MT1-MMP expression were abolished with chelation of extracellular calcium, and reinstated with its re-introduction. Spreading and retraction were inhibited by blocking the stretch-activated and L-Type voltage-gated channels, respectively; channel blocking also inhibited MT1-MMP upregulation. Channels’ role was confirmed through treatment with calcium A23187 ionophore, which alleviated the effects of channel blocking. Calcium regulated the integrin-mediated signalling pathway, which was facilitated through the kinase Src. Both calcium- and integrin-mediated pathways converged on activating ERK in response to stimulation. Understanding the molecular mechanisms regulating chondrocyte mechanotransduction may lead to the development of improved bioengineered cartilage.

Keywords: Mechanotransduction
Chondrocytes
Advisor: Kandel, Rita A.
Performance Measures for Forest Fire Management Organizations

Evaluating options, making informed decisions, measuring performance, and achieving management objectives in forest fire management organizations (FFMO) requires the development and application of measures that reflect how an organization has managed challenges presented. This thesis makes use of historical fire records from 1961 – 2008 to assess the impact of weather and management interventions on fire suppression effectiveness and annual area burned (AAB) within Alberta’s Boreal Natural Region. Statistical models relating AAB to variations in the proportion of extreme fire behaviour potential days suggest a significant portion of inter-annual variation in AAB (82 %) can be explained by the proportion of days when the Build-Up Index exceeds its 95th percentile. Probability of containment and large fire occurrence models are also developed that provide the framework for a new approach to presuppression planning in Alberta that can account for factors significantly influencing fire occurrence and containment outcome.

Keywords: Forest Fire Management
Initial Attack
Advisor: Martell, David Lee
Crossmodal Modulation as a Basis for Visual Enhancement of Auditory Performance

The human sensory system processes many modalities simultaneously. It was believed that each modality would be processed individually first, and their combination deferred to higher-level cortical areas. Recent neurophysiological investigations indicate interconnections between early visual and auditory cortices, areas putatively considered unimodal, but the function remains unclear. The present work explores how this cross-modality might contribute to a visual enhancement of auditory performance, using a combined theoretical and experimental approach. The enhancement of sensory performance was studied through a signal detection framework. A model was constructed using principles from signal detection theory and neurophysiology, demonstrating enhancements of roughly 1.8dB both analytically and through simulation. Several experiments were conducted to observe e ects of visual cues on a 2-alternative-forced-choice detection task of an auditory tone in noise. Results of the main experiment showed an enhancement of 1.6dB. Better enhancement also tended to occur for more realistic relationships between audio to visual stimuli.

Keywords: crossmodal
audio-visual
multisensory
auditory detection
visual enhancement
sensory modelling
Advisor: Wong, Willy
Validation of an Enhanced Questionnaire Designed to Assess Stress and Social Support in Patients with Chronic Periodontitis

Background: In this study, we enhanced a diagnostic questionnaire which had been previously developed to measure stress and social support. Methods: 101 patients with chronic periodontitis and 50 healthy control subjects completed our questionnaire package after which we analyzed the data for trends and associations. Results: Our enhanced questionnaire provided a valid and reliable measure of stress and social support in patients with chronic periodontitis. Conclusion: Our enhanced questionnaire provided both a valid and a reliable measure of stress and social support in patients with chronic periodontitis however requires further refinement to predict periodontal disease experience and severity.

Keywords: Chronic Periodontitis
Stress
Social Support
Questionnaire
Advisor: Glogauer, Michael
A Study of Melatonin for Premedication Prior to Anesthesia

Background: Anxiety is a barrier to dental care for many people. Preliminary studies suggest that melatonin may possess anxiolytic and sedative properties. Methods: Twelve subjects were selected for this study which compared melatonin, at a dose of 0.14 mg/kg, with placebo, as an oral premedication for anxious dental patients prior to receiving a general anesthetic. A visual analog scale (VAS) was used to measure anxiety. The Richmond Agitation Sedation Scale (RASS) was used to assess sedation, the Trieger Dot Test (TDT) for psychomotor impairment, and Digit Symbol Substitution Test (DSST) for cognitive impairment. A Quality of Recovery Questionnaire (QoR) was completed 24 hours after each appointment. Results: There were no significant differences in VAS scores for melatonin and placebo between baseline and at 30, 60, and 90 minutes. Similar results were found for RASS scores, TDT, DSST, and the QoR. Conclusion: At the doses used in this study, melatonin was not significantly different from placebo in anxiolysis, sedation, cognitive impairment, psychomotor impairment, and quality of recovery from anesthesia, for anxious dental patients.

Keywords: Melatonin
Premedication
Adults
Anesthesia
Dentistry
Anxiety
Advisor: Haas, Daniel
The Effect of Glucagon-like Peptide-2 on Insulin-like Growth Factor-1 in Murine Intestinal Subepithelial Myofibroblasts

Insulin-like growth factor-1 (IGF-1), a known secretory product of intestinal subepithelial myofibroblasts (ISEMF), is essential for the intestinotrophic effects of glucagon-like peptide-2(GLP-2). I hypothesized that GLP-2 increases the production of IGF-1 by primary murine ISEMF in culture. Immunocytochemistry showed that the ISEMF stained appropriately for α smooth muscle actin and vimentin but not for desmin. The ISEMF also expressed GLP-2 receptor and IGF-1 mRNA transcripts. ISEMF treated with GLP-2 revealed a maximal increase in IGF-1 mRNA transcript levels at 10-8 M GLP-2 and 2hr. Interestingly, immunoblotting revealed an increase in P-AKT/T-AKT with GLP-2, but no changes in cAMP, P-ERK/T-ERK or calcium were detected. PI3K inhibition and kinase-dead AKT over-expression abrogated GLP-2-induction of IGF-1 mRNA, and ISEMF from GLP-2R null mice demonstrated reductions in IGF-1 mRNA and cellular IGF-1, but not in media IGF-1, vs. wild-type ISEMF. These findings suggest a possible mechanism by which GLP-2 increases intestinal growth in-vivo.

Keywords: Cell cultures
Glucagon-like peptide-2
Subepithelial myofibroblasts
Insulin-like growth factor-1
PI3K/AKT signaling
Intestinal growth
Real time RT-PCR
Western blots
Immunocytochemistry
RIA
Advisor: Brubaker, Patricia
Parliamentary Privilege: A Relational Approach

Parliamentary privilege encompasses certain special rights and immunities deemed necessary to protect legislatures and members from undue interference so that they can effectively carry out their functions of inquiring, debating and legislating. The doctrine has engendered conflicts that have never been wholly resolved between courts and legislatures, and between individual rights and parliamentary privileges. The advent of modern human rights and emphasis on democratic values such as accountability and transparency has brought a new urgency to this problem. The current passive and defensive approach of Canadian legislatures is unsustainable, as is the approach taken by the SCC in recent jurisprudence. The paper argues against expanding the scope of judicial review of privilege claims as a solution, and in favour of open modernization processes led by parliamentarians, and involving public participation. Further, the paper advocates for the application of a “relational approach” versus the traditional “contest approach” to parliamentary privilege.

Keywords: parliamentary privilege
Advisor: Sossin, Lorne
Evaluation of a Colorimetric Assay as a Screening Test for Peridontal Disease

Background: Periodontal diagnosis relies on intraoral observable clinical factors including bleeding, probing depths, attachment loss, bone loss, and amount of plaque and calculus. Objective: To correlate neutrophil quantity and a colorimetric assay from an oral rinse with level of periodontal disease. To use this assay as a screening test for periodontal disease. Methods: Periodontal examinations of patients with healthy periodontium and periodontal disease were performed (n=125). Two concurrent saline rinses, 20 seconds each, were collected. Neutrophils were counted in each rinse. ABTS, a colour changing redox reagent, was added. The colour change was documented. Descriptive statistics, Spearman’s correlation, PPV, NPV, sensitivity and specificity were calculated. Results: Statistically significant correlation was found between neutrophils and colour change (rs=0.80, p<0.001); PPV and NPV for bleeding were 0.74 and 0.73, respectively. Conclusions: There is a correlation between neutrophils, colour change, and periodontal disease. The colorimetric assay can be used as a screening test for periodontal inflammation.

Advisor: Glogauer, Michael
Central Nervous System Nutrient-sensing and the Regulation of Energy and Glucose Homeostasis

Hypothalamic lactate metabolism regulates hepatic glucose and lipid homeostasis, however it remains unclear whether hypothalamic lactate also controls energy homeostasis. Furthermore, the precise downstream molecular and signaling pathway(s) involved in hypothalamic lactate-sensing is yet to be fully elucidated. To specifically address these two questions, we tested the hypothesis that hypothalamic lactate metabolism regulates energy homeostasis (Study 1) and assessed whether the activation of N-methyl-D-aspartate (NMDA) receptors in the nucleus of the solitary tract (NTS) of the brainstem is required for hypothalamic lactate, and sufficient per se, to regulate glucose homeostasis (Study 2). In an in vivo rat model, we reported in Study 1 that central lactate lowers food intake and body weight through its metabolism into pyruvate. In Study 2, we identified that hypothalamic lactate metabolism requires the activation of NMDA receptors in the NTS to lower hepatic glucose production. Moreover, we showed that the activation of NTS NMDA receptors per se lowers hepatic glucose production. In summary, these findings advance the understanding of central nutrient-sensing in the regulation of energy and glucose homeostasis, which is critical in bridging the therapeutic gap of obesity and type 2 diabetes.

Keywords: Diabetes
Obesity
Central Nervous System
Nutrient-Sensing
Glucose Homeostasis
Energy Homeostasis
Advisor: Lam, Tony K. T.
The Effects of Maternal and Postnatal Folic Acid Supplementation on Mammary Tumor Risk in the Offspring in a Chemical Carcinogen Rodent Model

Intrauterine exposures to environmental factors have been hypothesized to influence the risk of breast cancer in adulthood. The majority of epidemiological studies suggest that dietary folate intake is inversely related to breast cancer, however, the evidence have been inconsistent. An animal study was performed to determine the relationship between in utero and postnatal dietary folate intervention and the risk of breast cancer in the DMBA rodent model. Supplementation of maternal and offspring diet with folic acid (5 mg/kg diet) was observed to significantly increase the risk of mammary tumor development in the offspring compared to controls (2 mg/kg diet). Maternal diet and tumor status were also found to be significant predictors of global DNA methylation. Our data suggests that high intrauterine and postnatal exposures to folic acid increases the risk of breast cancer development. Epigenetic modifications may be an underlying mechanism by which folate mediates mammary tumorigenesis in the offspring.

Keywords: Folic Acid
Breast Cancer
Advisor: Kim, Young-In
Behavioural Analysis of Zebrafish: Shoaling and Fear Responses

Zebrafish, a novel vertebrate model organism, has a high nucleotide sequence homology with human genes. Its transparent and fast developing embryo allows the analysis of physiological and anatomical characteristics, many of which are similar to those of mammals. Although the prolific nature of zebrafish can facilitate genetic studies, linking genes and behaviour is difficult because behaviour is not well investigated in zebrafish. The aim of this project is to develop robust behavioural tests that can quantify shoaling with conspecifics and fear responses to natural predators. Eight conditions using different computer-animated stimuli were used to induce behavioural responses. The results demonstrate that shoaling behaviours and fear responses can be successfully induced. More importantly, the behaviours caused by the computer-animated images confirm previous research findings using natural conspecifics and predators. Thus, computer-animated images will help standardize behavioural tests in zebrafish and will lead the way to more sophisticated and better controlled experiments.

Keywords: behaviour
behavior
zebrafish
fear
shoaling
computer animated images
computer-animated
conspecifics
predators
anxiety
behavioural analysis
model organism
social paradigm
Indian Leaf fish
Needle fish
Advisor: Gerlai, Robert
Hardware Acceleration of a Monte Carlo Simulation for Photodynamic Therapy Treatment Planning

Monte Carlo (MC) simulations are widely used in the field of medical biophysics, particularly for modelling light propagation in biological tissue. The iterative nature of MC simulations and their high computation time currently limit their use to solving the forward solution for a given set of source characteristics and tissue optical properties. However, applications such as photodynamic therapy treatment planning or image reconstruction in diffuse optical tomography require solving the inverse problem given a desired light dose distribution or absorber distribution, respectively. A faster means for performing MC simulations would enable the use of MC-based models for such tasks. In this thesis, a gold standard MC code called MCML was accelerated using two distinct hardware-based approaches, namely designing custom hardware on field-programmable gate arrays (FPGAs) and programming commodity graphics processing units (GPUs). Currently, the GPU-based approach is promising, offering approximately 1000-fold speedup with 4 GPUs compared to an Intel Xeon CPU.

Keywords: Photodynamic therapy
Hardware acceleration
Monte Carlo simulation
MCML
Treatment planning
Graphics processing unit (GPU)
Field programmable gate array (FPGA)
Advisor: Lilge, Lothar
Rose, Jonathan S.
Effects of Emotional Expressions on Eye Gaze Discrimination and Attentional Cuing

Recent evidence has shown that our emotional facial expressions evolved to functionally benefit the expression’s sender, in particular fear increasing and disgust decreasing sensory acquisition. Using schematic eyes only that lack emotional content, but taken from actual participant fear and disgust expressions, we examined the functional action resonance hypothesis that adaptive benefits are also conferred to the expression’s receiver. Participants’ eye gaze discrimination was enhanced when viewing wider, “fear” eyes versus narrower, “disgust” eyes (Experiment 1). Using a gaze cuing paradigm, task facilitation by way of faster responses to target was found when viewing wider versus narrower eyes (Experiment 2). Contrary to our hypothesis, a null attention modulation for wider versus narrower eyes was found (Experiments 2 and 3). Nonetheless, the evidence is argued for the functional action resonance hypothesis.

Keywords: Emotions
Eye Gazes
Facial Expressions
Advisor: Anderson, Adam K.
Pratt, Jay
Exploring the Neural Basis of Working Memory: Using Probabilistic Tractography to Examine White Matter Integrity and its Association to Working Memory in Paediatric Brain Tumor Patients

Paediatric posterior fossa tumors are often effectively controlled with a combination of radiation, chemotherapy and surgery. However, therapeutic craniospinal radiation has been associated with widespread cognitive late effects. Working memory is one such cognitive ability that has yet to be fully examined in this clinical population. Bilateral tracts connecting the cerebellum with the DLPFC were delineated using DTI tractography in all participants, replicating the cerebrocerebellar pathway outlined in an animal model. There were observable differences in white matter integrity (quantified by DTI measures of anisotropy, and mean, axial, and radial diffusivity) of the cerebellum-DLPFC pathway in patients versus controls. Additionally, working memory deficits that were found in patients were correlated with DTI indices pertaining to the cerebellum-DLPFC pathway. Therefore, this thesis is the first to explore the possible relations between white matter integrity of this pathway following treatment for paediatric posterior fossa tumors and working memory function.

Keywords: posterior fossa tumors
DTI tractography
working memory
craniospinal radiation therapy
Advisor: Mabbott, Donald