VictorJuiz/thesis huggingface dataset:
Eye movements as a Predictor of the Perception and Memory of Scenes

We investigated how eye gaze patterns are implicated in the perception and memory of scenes. Firstly, we explored whether eye movements during scene perception reflect scene-specific information. Furthermore, we tested whether these specific patterns of eye movements are beneficial for successful memory encoding and retrieval. Participants studied photographs and line drawings of real-world scenes while their eye movements were tracked. Eye gaze patterns during study are predictive of both scene category and subsequent memory of the scene. Moreover, gaze patterns during study are more similar to gaze patterns during test when the image is successfully recognized than when it is forgotten. In experiment 2, recognition rate was not affected by disrupting the spatial or temporal context of the repeated eye movements. Thus we conclude that eye movements serve to access and select the most relevant content in a scene, namely, distinct objects and contour junctions, in order to cue memory.

Keywords: Attention
Eye Tracking
Memory
Scene Perception
Advisor: Bernhardt-Walther, Dirk
A Dynamics Systems Approach to Interpersonal Behavior as a Function of Interpersonal Values

According to the cybernetic theory of self-regulation proposed by Carver and Scheier (1998), a value serves as a reference point toward which an individual’s behavior will gravitate. The current study examined this hypothesis through the recruitment of 140 undergraduate students at a southern Ontario university. Participants self-reported their interpersonal values and were then divided into four-person groups that cooperated to solve the “Lost on the Moon” puzzle. The behaviour of each participant during interaction was videotaped and coded using the joystick technique (Sadler, Ethier, Gunn, Duong, Woody, 2009) and then subjected to attractor analyses using GridWare (Lamey, Hollenstein, Lewis, Granic, 2004). Contrary to our hypothesis, no attractors were identified, although average agentic behavior was significantly associated with agentic values. The failure to identify attractors was perhaps due to a lack of within person variability, as the participants were more strongly influenced by individual differences and group characteristics.

Keywords: attractor
interpersonal behavior
interpersonal value
self-regulation
state space grid
Advisor: Fournier, Marc A.
Effectiveness of the Lorodent Probiotic Lozenge in Reducing Plaque and S. Mutans Levels in Orthodontic Patients: a Randomized, Double-blind, Placebo-controlled Trial

Background/Objectives: To determine the efficacy of the Lorodent probiotic complex at reducing plaque accumulation and Streptococcus mutans levels in adolescent orthodontic patients. Methods: 60 adolescent orthodontic patients were randomized in a double-blind, parallel-group, placebo-controlled trial to receive either the Lorodent probiotic or placebo lozenge orally every day for a 28-day administration period. Plaque scores, supragingival plaque samples and saliva samples were assessed over a total of 56 days. Results: Participants receiving the placebo lozenge had a greater improvement in plaque scores compared to those receiving the Lorodent probiotic lozenge. There were no significant changes in S. mutans and total lactobacilli levels between the probiotic and placebo groups. Lozenge consumption compliance was over 90% and no adverse events were observed in the probiotic group. Conclusions: The Lorodent probiotic lozenge did not decrease plaque or S. mutans levels in adolescent patients undergoing fixed orthodontic appliance treatment. Funding: Ontario Centres of Excellence.

Keywords: clinical trial
orthodontics
plaque
probiotics
s. mutans
white spot lesions
Advisor: Gong, Siew-Ging
A Multi-domain Co-simulator for Smart Grid: Modeling Interactions in Power, Control and Communications

Smart grid studies have been generating a lot of interest both in the business and research community as it is now seen as the future power grid. However, understanding the interactions amongst different components that form the smart grid is a Herculean task. Researchers rely on simulations as one of the means of understanding the effects of coupling the distributed control systems, communication networks and power system to form the smart grid, but synchronization of the simulation times of the various simulators, and data exchange amongst the different components are challenges that must be overcome. Fixed-time-step and queuing system synchronization schemes have been proposed, but the fixed-time-step synchronization scheme suffers from accumulation errors and the proposed queuing method does not scale well. In this thesis, we present a synchronization scheme that eliminates accumulated synchronization errors, and efficient data exchange scheme which enhances the scalability of the platform.

Keywords: Co-Simulation
OMNeT++
PSCAD/EMTDC
Scheduler
Smart Grid

Synchronization
Advisor: Kundur, Deepa
Investigating the Evolutionary Forces Acting on Mammalian Transcription Factor Binding

Transcription factors (TFs) transcriptionally regulate genes by binding nearby sequence elements. The evolutionary mechanisms driving the evolution of TF binding events between species are unclear. This thesis addresses three disparate predictions of natural selection acting on different sets of mammalian TF binding events: TF binding events predicted to be degenerating, deeply shared binding events that are predicted to be under stabilizing selection and recently gained and lost binding events which could be targets of positive selection. I begin by showing that TF binding levels nearby primate pseudogenes have recently decreased relative to functional liver genes, but there is no clear evidence of degeneration at the sequence level. I next demonstrate with a likelihood ratio test that binding events shared across mammals are under stabilizing selection. Lastly, I show that there is no evidence for positive selection driving binding turnover based upon a modified McDonald-Kreitman test.

Keywords: ChIP-seq
Natural selection
Regulatory evolution
Transcription factor
Advisor: Moses, Alan M
Musculo-aponeurotic Architecture of the Human Masseter Muscle: A Three-dimensional Cadaveric Study

Masseter muscle (MM) has been found to undergo morphological changes in temporomandibular disorders (TMDs). These changes are poorly understood even though muscle architecture is an important determinant of function. The purpose was to model and quantify the musculo-aponeurotic architecture of MM in 3D. In total, 9300 FBs were digitized and modeled from 8 formalin-embalmed specimens (mean age 74.9±15.9 years). Each MM consisted of multi-laminar superficial (SH) and deep heads (DH), with FBs spanning between superior and inferior aponeuroses. Superficial head had FBs that were on average 12mm longer than DH, 3 times the physiological cross-sectional area and 4 times the volume. On average SH had 3 laminae with 5 aponeuroses, while DH had 2 laminae with 2 aponeuroses. The results of this study can be used to develop in vivo ultrasound protocols for studying normal and pathologic muscle architecture and construct finite element models for simulating functional biomechanics in the muscle.

Keywords: Architecture
Masseter
Modeling
Temporomandibular Disorders
Advisor: Agur, Anne M
Heterogeneity in the Reporting of Mortality in Critically Ill Patients during the 2009-10 Influenza A (H1N1) Pandemic: A Systematic Review and Meta-regression Exploring the Influence of Patient, Healthcare System and Study-specific Factors

Introduction: A systematic review with meta-regression to determine heterogeneity in reported mortality associated with critical illness during the 2009-2010 Influenza A (H1N1) pandemic. Results: We identified 219 studies from 50 countries that met our inclusion criteria. There were significant differences in the reported mortality based on the geographic region and economic development of a country. Mortality for the first wave of the H1N1 pandemic was non-significantly higher than wave 2. In our hierarchical model the reported mortality was heavily influenced by the need for mechanical ventilation. Conclusion: While patient-based factors are influential in determining outcomes during outbreaks and pandemics, the region and system of care delivery also influence survival. Outcomes from a relatively small number of patients, early in an outbreak and from specific regions may lead to biased estimates of outcomes on a global scale. This may have important implications for global disease outbreak responses.

Keywords: Critical Illness
Influenza A (H1N1)
Mechanical Ventilation
Metaregression
Pandemic
Advisor: Fowler, Rob
The Significance of Pearls in Premodern China

Pearls have played a significant role in the lives of the premodern Chinese people for over two thousand years, and are still very much treasured nowadays. Many general Chinese beliefs, customs, and practices surrounding pearls have been taken for granted as received knowledge, without careful examination to explain the long-lasting admiration and reverence that pearls have received in Chinese history. This thesis demonstrates that pearls were more than just gems used in jewelry making for the premodern Chinese people. It explains the reasons behind assumed knowledge such as the high prices, the perceived magical power, and the medicinal value of pearls in premodern Chinese culture in order to help us understand why pearls have enjoyed an unrivaled significance in premodern China, thus allowing us to further develop our understanding and appreciation for premodern Chinese culture as a whole.

Keywords: China
Chinese culture
pearls
Advisor: Sanders, Graham
Global Visual Motion Affects the Distribution of Spatial Attention

Decades of research has established that spatial attention concentrates near the centre of the visual field, attenuating sharply toward the periphery. In a static scene, humans are better at deploying attention to objects among clutter that appear near central vision. However, while walking or driving people often encounter global motion of the visual environment. Little is known about this motion’s impact on spatial attention, or whether the arrangement of distractor objects impacts target detection. The current study investigated whether (1) a random distractor arrangement and (2) target and distractor motion impact the distribution of spatial attention. Experiment 1 shows that distractor arrangement does not affect spatial attention. Experiment 2 shows that humans are better at detecting targets across the visual field when there is global motion. Spatial attention in a static context differs from spatial attention in a dynamic context; thus, previous knowledge may not generalize to some contexts.

Keywords: attentional visual field
global motion
motion
optic flow
spatial attention
UFOV
Advisor: Spence, Ian
Campos, Jennifer
Accelerometric Detection of Intentional Movements in the Presence of Dyskinesia

This study investigated the potential to automatically decode unidirectional arm movements (up, down, left, and right), using an array of six muscle-situated tri-axial accelerometers in children with and without movement disorders. Fifteen typically developing children (aged 11±2 years) and four children with movement disorders (aged 9 ± 1.2 years) participated in the study. Participants repeatedly drew horizontal and vertical lines on the tablet using a digital stylus. In the typically developing group, the four movements could be discriminated with participant-independent classifiers (~80% accuracy) using either motion signals or their combination with low frequency MMG. For participants with movement disorders, neither motion nor its combination with low frequency MMG yielded high accuracy, possibly due to muscle atrophy and inconsistent muscle tone. In both groups, MMG alone provided the lowest accuracy. Low force contractions and developmental variations in the mechanical properties of muscles were likely contributing factors.

Keywords: Children
Dyskinesia
Hidden Markov Models
Mechanomyography
movement prediction
upper extremity
Advisor: Chau, Tom
The Role of Bacterial Products and Intestinal Microbiota in Non-alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) includes simple steatosis (SS) and non-alcoholic steatohepatitis (NASH), which can progress to cirrhosis. NAFLD pathogenesis is complex. Recent research suggests a role for the intestinal microbiota (IM) with various potential mechanisms involving bacterial metabolism and products. This cross-sectional study compared bacterial products and metabolites in the blood and feces, and fecal levels of total bacteria, Bacteroidetes, C. coccoides, C. leptum, Bifidobacteria, Lactobacilli, E. coli and Archaea in biopsy confirmed SS, NASH, and healthy controls (HC). NAFLD patients (SS+NASH) had higher levels of bacterial fecal metabolites, including choline, trimethylamine, total short-chain fatty acids, propionate, isobutyric acid, and higher serum 2-hydroxybutyrate than HC. NASH patients had lower proportions of fecal C. leptum and higher amounts of E. coli than HC. Several bacterial metabolites correlated with histological findings, and with specific bacteria and diet. These findings suggest a potential role for bacteria and bacterial metabolism in NAFLD pathogenesis.

Keywords: endotoxin
intestinal microbiota
non-alcoholic fatty liver disease
non-alcoholic steatohepatitis
short-chain fatty acids
Advisor: Allard, Johane P
Catecholamines as Independent Predictors of Outcome in Moderate and Severe Traumatic Brain Injury (TBI). The COMA-TBI Study

Introduction: High levels of catecholamines post brain trauma are associated with severity of injury and neurological outcome. We aimed to overcome methodological limitations of previous studies and demonstrate an independent association between circulating catecholamine levels with neurological outcome in patients with isolated brain injury. Methods: Multi site, prospective observational blinded cohort study. After enrollment, patients had catecholamine levels measured on admission and the independent association with a 6-month neurological outcome was assessed using the Glasgow Outcome Scale Extended. Multivariate logistic regression models estimated the adjusted odds ratio for prediction of unfavorable outcome. Results: 181 patients were enrolled and admission catecholamines were measured. High admission levels were independently associated with severity of injury and with unfavorable outcome. Conclusion: We demonstrated the natural history of catecholamine release early post brain injury and an independent association with unfavorable outcome in a dose response fashion. Catecholamines are biomarkers of outcome in moderate to severe traumatic brain injury.

Keywords: Biomarkers
Brain injury
Catecholamines
Epinephrine
Norepinephrine
Prognosis
Advisor: Rizoli, Sandro b
Soot Formation at High Pressures in Laminar Liquid and Gaseous Fuel Flames

Laminar co-flow diffusion flames were studied in 1) nitrogen-diluted ethylene flames at 1:1, 1:2, and 1:4 mass ratios (C2H4: N2) at 10 atm (compared to previous results at a 1:3 ratio), and 2) liquid-doped methane flames with 7.4% of carbon from liquid fuel using ethanol and n-heptane up to 8 atm and toluene up to 6 atm. Soot spectral emission measurements were deconvoluted using Abel inversion to provide radially resolved soot volume fraction and temperature profiles. In the former, soot production was proportional to fuel concentration, and flame temperatures increased at higher dilution ratios. In the latter, toluene-doped flames produced the most soot, followed by n-heptane- and ethanol-doped flames. Soot production in ethanol-doped flames was higher than expected, and possible mechanisms for this are discussed including synergistic effects. Flame temperatures were inversely proportional to soot concentration, and the pressure dependence of soot formation is compared to previous measurements.

Keywords: aviation
biofuel
combustion
flame
pressure
soot
Advisor: Gülder, Ömer L
Teaching about Race and Racism: History Education, Teacher Subjectivity, and Pedagogical Practices

This Master’s thesis examines how a history teacher subject position emerges from the discursive practices of history teachers teaching about race and racism in Canadian history. It use semi-structured and focus group interviews, classroom observations, and analysis of documents and cultural-visual material to track the formation of the subject position across a range of discursive and material contexts. Through Foucault’s theories on power/knowledge and governmentality, the researcher identifies how the role of the history teacher subject serves as rationalization to the deployment of history as moral education for students. She illustrates how the history teacher subject produces and mediates knowledge of race and racism in curriculum and manages their own conduct in order to mobilize student affect, while considering how pedagogy inherently fails as a practice of prediction and control. These findings have implications for educators and researchers interested in history education, teacher identity, and teaching about race and racism.

Keywords: Canadian history
History education
Pedagogy
Poststructuralism
Secondary education
Teacher Identity
Advisor: Sintos Coloma, Roland
Where is Queer? Migration Experiences of Sexual Minority International Students in Toronto

This qualitative study uses queer standpoint and queer oral history methods to examine the migration experiences of nine globally mobile LGBTQ international students currently studying or recently graduated from post-secondary institutions within the Greater Toronto Area (GTA) and southern Ontario. I employ Lionel Cantú’s queer materialist paradigm to interrogate the ways in which queer international students are subject to and disciplined by dominant relations of ruling within specific educational and queer sites of citizenship. In particular, I attend to the ways in which intersections of race, gender, class, language, and other identity markers mediate experiences of home and belonging in both physical and virtual worlds within these citizenship spaces, and how these students engage in forms of “border-crossing” to consciously re-articulate or redeploy aspects of their identity in order to strategically negotiate particular regimes of power and privilege.

Keywords: Adult education
Border-crossing
Higher education
International students
Migration experiences
Queer
Advisor: Mirchandani, Kiran
Examing the Influence of Parental Pressure and Perceived Control on Young Adults' Career Exploration

This study explored the career development and exploration experiences of young adults in Canada, through the lens of parental pressure experiences and perceptions of control. Using a grounded theory approach and a qualitative methodology, in-depth interviews were conducted to analyze participant narratives. Key themes emerged. Participants experienced more parental pressure in their university years compared to childhood or high school years. They engaged in more career exploration and placed a higher emphasis on person-career and person-academic fit during university years. Parental pressure did not seem to affect career exploration in later years, when other factors were contributing to career exploration. With regard to perceived control, most participants held a moderate to high level of perceived control over their overall and career environments, but felt that parental pressure reduced control over their career future. The results have implications for vocational psychology and career counselling with young adults.

Keywords: career
career development
career exploration
parental pressure
perceived control
young adults
Advisor: Chen, Charles
A Comparative Study of Repetitive Behaviours in Pediatric Obsessive-compulsive Disorder and Autism Spectrum Disorder

Repetitive behaviours are a core feature and source of impairment in two neurodevelopmental disorders: obsessive-compulsive disorder (OCD) and autism spectrum disorder (ASD). However, few studies have systematically examined repetitive behaviours across these two disorders. As part of the Province of Ontario Neurodevelopmental Disorders network we compared repetitive behaviour subtypes in children and adolescents with OCD and ASD using several instruments. Findings revealed marked heterogeneity of repetitive behaviour subtypes in children and adolescents with OCD and ASD. Results suggest repetitive behaviour subtypes that are more common in OCD, ASD, and equally prevalent across disorders. Findings will help guide future pathophysiological studies by localizing dimensional traits of repetitive behaviours across disorders.

Advisor: Arnold, Paul D
How is International Experience Considered during Local Teacher Hiring?

Many Canadian Ontario-educated teachers are gaining international experience—either prior to entering a faculty of education, during their degree programs, or upon graduation—before seeking teaching jobs “at home.” For this study, 131 administrators from Ontario public, Catholic and private/independent schools completed a quantitative, online anonymous survey, which sought to see if international experience is an advantage during the local hiring process. Participants were recruited through school boards, schools, e-newsletters and directly. Results were reviewed for a central tendency. Administrators generally indicated that they are aware of international opportunities available, and that they believe these experiences can develop teachers’ knowledge, skills and abilities; however, when hiring, international experience is not necessarily an advantage on its own, including for those who have completed international experiences themselves. Other legislative requirements and board policies may also play a role in determining the hiring decisions, particularly in publicly-funded schools and school boards.

Keywords: education
experience
hiring
international
principal
teacher
Advisor: Gaskell, Jane
Magnetic Resonance Enterography for the Assessment of Inflammation in Pediatric Crohn’s Disease

Magnetic resonance enterography (MRE) is an emerging method of assessment in Crohn’s disease (CD) and this thesis represents the first steps (item generation) in developing 2 new MRE-based, multi-item measures of inflammation and damage. Through a systematic-review and meta-analysis, 22 MRE signs used to reflect inflammation and 9 to reflect damage were discovered. The most accurate signs for inflammation were wall enhancement, mucosal lesions and wall T2 hyperintensity (most sensitivities>80% and specificities>90%), and the most accurate signs for damage were abscess and fistula (most sensitivities>90%, specificities>95%). A cross-sectional study found that among 49 patients with CD at SickKids, wall enhancement, wall T2 hyperintensity, wall thickening, and wall diffusion restriction were commonly identified and had highest sensitivity and specificity. Additionally, although not as commonly identified, mucosal lesions were also accurate. These 5 MRE signs should be included in multi-item indices for CD.

Keywords: Crohn's disease
damage
diagnostic test accuracy
inflammation
magnetic resonance enterography
pediatrics
Advisor: Feldman, Brian M