VictorJuiz/thesis huggingface dataset:
Diapers and Downloads: How Young Mothers Negotiate the Pressures of Finishing their Secondary School Education Online

Online learning is increasingly regarded as a way to accommodate the needs of students who are compromised by geography, health, and socio-economic status. This research examines the experiences of young single mothers who are enrolled in online courses in order to graduate from secondary school. With the promise of anytime, anywhere education, women who have not been able to complete secondary school enroll in online courses with an expectation that they will be able to care for their children and complete courses while at home with relative ease. Using the dual lenses of poststructuralism and critical theory, this research investigates how the prevailing assumptions concerning the benefits of online learning accord with the experiences of this particular group of women and how the dominant societal discourses surrounding educative technologies are reflected in the women's utterances.

Keywords: adult education
critical theory
discourse analysis
online learning
poststructuralism
Advisor: Brett, Clare
The Challenges of Restoring Binaural Hearing: A Study of Binaural Fusion, Listening Effort, and Music Perception in Children using Bilateral Cochlear Implants

Benefits from bilateral implantation vary and are limited by mismatched devices, stimulation schemes, and abnormal development. We asked whether bilateral implant use promotes binaural fusion, reduces listening effort, or enhances music perception in children. Binaural fusion (perception of 1 vs. 2 sounds) was assessed behaviourally and reaction times and pupillary changes were recorded simultaneously to measure effort. The child's Montreal Battery of Evaluation of Amusia was modified and administered to evaluate music perception. Bilaterally implanted children heard a fused percept less frequently than normal hearing peers, possibly due to impaired cortical integration and device limitations, but fusion improved in children who were older and had less brainstem asymmetry and when there was a level difference. Poorer fusion was associated with increased effort, which may have resulted from diminished bottom-up processing. Children with bilateral implants perceived music as accurately as unilaterally implanted peers and improved performance with greater bilateral implant use.

Keywords: binaural hearing
children
cochlear implants
deafness
listening effort
music perception
Advisor: Gordon, A Karen
The Spectrum of Hepatic Involvement in Pediatric Inflammatory Bowel Disease: An Analysis of the Development of Abnormal Liver Enzymes and Associated Clinical Variables

Hepatic involvement in pediatric Inflammatory Bowel Diseases (IBD) includes presentation with abnormal liver enzymes (LEs). A proportion of these children do not develop serious hepatic consequences. We sought to describe the natural history of the development of abnormal LEs and associated clinical variables. A carefully phenotyped cohort of 300 children with IBD (

Keywords: Autoimmune sclerosing cholangitis
Inflammatory bowel diseases
Liver enzymes
Primary sclerosing cholangitis
Advisor: Brian, M Feldman
Effectiveness of Educational Materials about Reducing Pain in Infants Receiving Immunizations in a Paediatric Outpatient Setting: A Cluster Randomized Trial

Background: Immunizations are common painful medical procedures for infants and educating parents at their paediatrician's office on pain management (PM) can help improve utilization of strategies.Objective: To determine the effectiveness of educating parents at the paediatric clinic on increasing the number of PM strategies utilized during their infant's immunization appointments.Methods: This was a partially blinded cluster randomized controlled trial at a paediatric clinic at St. Michael's Hospital where parents were randomized by groups according to their paediatrician. Parents in the intervention group received written and video information on immunization PM and parents in the control group did not.Results: 160 parent-infant dyads from 4 physician clinics were observed during their immunization procedure. A statistically significant increase (p

Keywords: immunization pain
infants
injection pain
pain management
vaccine
Advisor: Taddio, Anna
A Pilot Study to Compare the Activity of Different Bone Morphogenetic Protein Bioimplants In Vivo

The challenge in BMP delivery is maintaining adequate amounts at the healing site over time. Burst release from absorbable collagen sponge (ACS) provides inefficient delivery. The aim of this study was to investigate biphasic calcium phosphates (BCP), calcium sulfate (CaS) and poloxamer in combination to deliver BMP. Different ratios of BCP to CaS were combined with rhBMP-2 divided between the scaffold and poloxamer and implanted in mice. Induced bone was quantified by microCT and confirmed by histology. Statistical analysis was performed using ANOVA.More bone was formed when CaS and BCP combined with poloxamer than compared to ACS (p

Advisor: Peel, Sean
Qualitative Analysis of Precipitate Formation on the Surface and in the Tubules of Dentin Irrigated with Chlorhexidine or QMiX® as a Final Rinse

This study examined the presence of precipitate and para-chloroaniline (PCA) in dentinal tubules (DT), after irrigation with NaOCl and CHX, or with NaOCl and QMiX®, using of Time-of-flight secondary ion mass spectrometry (TOF-SIMS). Human upper molars dentin blocks were embedded in resin. Group 1 was irrigated with 2.5%NaOCl, followed by 17%EDTA, 2.5%NaOCl, and 2%CHX. Group 2 was irrigated with 2.5%NaOCl, saline and QMiX®. TOF-SIMS spectra were obtained. Longitudinal sections of the irrigated blocks were exposed and examined with TOF-SIMS. All samples and analyses were triplicated for confirmation. Group 1 samples had irregular precipitate containing PCA on the surface and extending into DT. In group 2, no precipitate was seen on the surface or in DT. PCA and precipitate were present in the tubules of dentin irrigated with NaOCl followed by CHX. No precipitate or PCA were detected in the tubules of dentin irrigated with NaOCl followed by saline and QMiX®.

Keywords: chlorhexidine
dentin
parachloroaniline
precipitate
QMiX
sodium hypochlorite
Advisor: Basrani, R Bettina
Development of Thermographic Phosphor Diagnostics For Gas Turbine Temperature Measurements

Laser induced phosphorescence (LIP) thermometry can provide spatially and temporally resolved temperature fields in harsh environment like gas turbine combustors with high-accuracy and a relatively simple setup. For measurement in gas turbine combustor, the employed thermographic phosphor (TP) should have high sensitivity and signal yield at high temperatures. It is known that phosphor composition, crystallinty, and morpholgy can affect the TP phosphorescence properties. Four high-temperature phosphors with different composition were prepared with sol-gel synthesis (SGS) here, viz. YAG:Dy, YAG:Dy:Er, YABNG:Dy, and YABG:Dy. The phosphor crystallinity and morphology were determined by x-ray diffraction spectroscopy (XRD) and scanning electron microscopy (SEM), respectively. The phosphor emissions were measured with a setup consisted of a UV laser, high temperature oven, and spectrometer. The integral of YABNG:Dy emission was 1.5 to 2 times higher than other investigated phosphors at temperatures above 1200 K. The increment in emission intensity improved the precision at high temperatures.

Keywords: SEM
Thermographic Phosphor
XRD
YABNG:Dy
YAG:Dy
YAG:Dy:Er
Advisor: Steinberg, M. Adam
Antipsychotic Tolerance: Evaluating the Behavioural Effects of Continuous Versus Intermittent Haloperidol Exposure

There are several lines of investigation, both preclinical and clinical, that suggest antipsychotic drug (APD) tolerance may occur. Using a behavioural animal model, the present study examined whether the amount of APD exposure (i.e. continuous versus intermittent) significantly impacts APD efficacy. More specifically, it was investigated whether continuous haloperidol (an APD) exposure, in comparison to intermittent, would lead to a decrease in response over time. Catalepsy, locomotor activity, and exploratory behaviour were assessed weekly, over the course of 21 days, in rats receiving haloperidol continuously or intermittently. Our findings are consistent with earlier preclinical reports that have implicated chronic and continuous APD therapy in reduced drug effect. This line of investigation has immediate and direct implications in terms of current guidelines regarding maintenance antipsychotic treatment. Moving forward, we are in a position to translate these results to clinical studies that can further examine this issue in humans.

Keywords: Antipsychotic tolerance
Behavioural animal model
Haloperidol
Intermittent therapy
Maintenance therapy
Schizophrenia
Advisor: Remington, J Gary
Measurement of Pulmonary Arterial Impedance and Reflection from Single-slice Phase-Contrast and Steady-state Free Precession MRI

Pulmonary arterial hypertension (PAH) alters vessel wall mechanics and vasomotor tone, driving up pulmonary hemodynamic variables such as pulse wave velocity, input and characteristic impedance, and pulse wave reflection magnitude. Heterogeneous treatment response necessitates frequent hemodynamic evaluation, for which right-heart catheterization (RHC) remains the gold standard; however, several disadvantages limit its frequency of use. In this work, a non-invasive magnetic resonance (MR) imaging protocol is developed to address the shortcomings of invasive hemodynamic monitoring and may support existing diagnostic procedures. First, accuracy and precision of the proposed method is characterized through linear uncertainty propagation and numerical simulation of the data-processing pipeline. Second, the MR protocol is tested in seven healthy adult volunteers. Third, a rapid version of the MR protocol is tested in a healthy volunteer, yielding good agreement with mean values obtained in the seven-volunteer study.

Keywords: magnetic resonance imaging
pulmonary arterial hypertension
pulmonary vascular resistance
pulse wave reflection
pulse wave velocity
vascular impedance
Advisor: Macgowan, K Christopher
Factors That Influence Force Steadiness in Individuals with Upper Limb Spasticity after Stroke

Individuals with post-stroke spasticity are disabled by paresis, soft-tissue shortening and muscle over-activity, which significantly affect functional motor output (FMO). Force steadiness (FS) describes the ability to maintain an isometric contraction, and is associated with functional task performance in healthy individuals. The coupling between FS and FMO suggests that FS may be a sensitive metric of FMO deficits that accompany spasticity that may not be captured using clinical scales. This thesis examined muscle weakness, muscle over-activity, and electromechanical coupling as potential factors influencing FS in upper limb spasticity. The affected limb was significantly less steady than the less-affected limb. Absolute force was negatively correlated with CV of force. However, co-activation indices were not different between limbs. Finally, flexor EMG was temporally correlated with force output. These measures may provide sensitive metrics of functional motor deficits that could be used as a tool to characterize effect of spasticity management interventions.

Advisor: Mochizuki, George
Investigation of the Role of JAK2 in SOCS1-mediated Granulocyte-macrophage colony-stimulating Factor Receptor Turnover

Our lab has recently shown that SOCS1 binds and degrades the granulocyte-colony stimulating factor receptor beta common subunit (GMRBc) in a proteasome-dependent manner. The focus of this project was to determine the role of JAK2 in SOCS1-mediated GMRBc turnover. Results: The binding of SOCS1 to GMRBc was observed in the JAK2-null gamma2A fibrosarcoma cell line. In TF1s, an erythroleukemic cell line that endogenously expresses GMRBc, transient knockdown of JAK2 resulted in the marked stabilization of GMRBc levels by thirty minutes. Using the kinase-dead K882E JAK2 mutant and the Y1007F JAK2 mutant, which abrogates SOCS1-binding as well as JAK2 activation because it is a key phosphorylation site, it was determined that the kinase activity of JAK2 is required SOCS1-mediated degradation of GMRBc. Lastly, SOCS1 has been predicted to bind Y468 on GMRBc.Conclusions: JAK2 is not necessary for SOCS1 to bind GMRBc; however, active JAK2 is necessary for substantial GMRBc degradation.

Keywords: GM-CSF receptor
JAK2
JMML
SOCS1
Advisor: Elsholtz, Harry
Investigating the oral microbiome in health and periodontal disease

16S rRNA was used to determine the microbiome associated with health and chronic periodontitis (CP). We hypothesized that a comparison of plaque in health and disease will help identify CP-associated bacteria to develop novel diagnostics for CP. NGS was done against the V3 hypervariable region of the 16S rRNA gene and sequences were clustered based on 97% similarity. Taxonomic assignment and distance measures were used to assess bacterial composition. We identified disease indicators: Filifactor alocis, Synergistes, Tanerella forsythia and TM7 taxa in SupG and SubG sites. Health indicators included Rothia dentocariosa, TM7_7BB428, Selenomonas noxia, Fusobacteriales and Campylobacter. Surprisingly, `classic' periodontal pathogens could be isolated from the tongue in CP patients, which may provide a novel sampling site for prognostic tests. We have identified known periodontal pathogens, including F. alocis, a strong indicator of CP, which could be included as a novel member in the Red complex of periodontal pathogens.

Keywords: microbiome
periodontal
Advisor: Cvitkovitch, G Dennis
Development of Bio-based Phenol Formaldehyde Novolac Resins Using Mountain Pine Beetle Infested Lodgepole Pine Barks

In this study, mountain pine beetle (MPB; Dendroctonus ponderosae) infested lodgepole pine (Pinus contorta) barks were converted to phenol substitutes using bark phenol liquefaction with sulfuric acid and hydrochloric acid catalysts. The bio-based phenol formaldehyde novolac resins were synthesized and characterized. The applications of these synthesized bio-based novolac PF resins in preparing thermal molding composites were also investigated.It was found that both acid catalysts were effective in the bark-phenol liquefaction for obtaining the adequate phenol substitutes from MPB infested lodgepole pine bark. The synthesized bio-based novolac PF resins have higher molecular weight, more complex resin structures and comparable curing behavior and thermal stability to the reference novolac PF resins without liquefied bark components. The HCl acid-catalyzed liquefied bark novolac PF resins were successfully molded into composites with comparable mechanical properties, thermal stability, bonding performance, and enhanced water resistance in comparison to the lab-made control novolac PF resin.

Keywords: Adhesive
Liquefaction
Molidng
MPB infested lodgepole pine bark
Novolac resins
Resin synthesis
Advisor: Farnood, R Ramin
Exploring the Relationship Between Principal Behaviour and Student Achievement

Leadership is critical in initiating and maintaining school improvement, yet the nature of that leadership, and its impact on school improvement remains a contentious issue. The following case study investigates how the leadership behaviour of a secondary school principal in Ontario relates to the improvement of student achievement as measured by the grade 10 Ontario Secondary School Literacy Test (OSSLT). This case study was undertaken as a result of remarkably good performance on Ontario's standardized literacy test over a period of four years. It takes into account the perceptions of both the principal and of teachers with respect to school culture and the subsequent effect on student achievement. Leithwood and Louis' (2012) four core leadership practices; setting direction, developing people, redesigning the organization, and improving the instructional program guided the study's framework.

Keywords: Leadershp
Literacy
Student Achievement
Advisor: Mascall, Blair
Imaging Alcohol Induced Dopamine Release in the Human Brain: a PET/[11C]-(+)-PHNO Study

Findings from previous positron emission tomography studies exploring the effect of acute alcohol on dopamine levels within the reward circuitry are inconsistent. However, the recently developed radiotracer, [11C]-(+)-propyl-hexahydro-naphtho-oxazin ([11C]-(+)-PHNO), may detect fluctuations in dopamine levels with greater sensitivity than previously used radiotracers. Seven social drinkers underwent two [11C]-(+)-PHNO PET scans following alcohol or placebo consumption in a randomized, single blind, crossover design. The non-displaceable binding potential (BPND) was examined in the striatum and extra-striatal regions (substantia nigra, globus pallidus, ventral pallidum) and compared between the two scans. There were no significant reductions in BPND in the alcohol scan compared to the placebo scan in any regions of interest, indicating no significant changes in dopamine levels. This is the first study to explore the alcohol-induced dopaminergic response in social drinkers using [11C]-(+)-PHNO. Our findings suggest that this response may be heterogeneous and the various factors influencing this response warrant further investigation.

Advisor: Foll, Bernard Le
Near-infrared Triggered Anti-Cancer Drug Release from Upconverting Nanoparticles

Externally-triggered drug delivery using functional nanoparticles has provided new strategies to improve therapeutic efficacy while concurrently minimizing toxicity. This thesis describes an investigation of photocleavage at the surface of UCNPs to release the chemotherapeutic 5-Fluorouracil (5-FU). Core-shell UCNPs composed of β-NaYF4: 4.95%Yb, 0.08%Tm / β-NaYF4 were decorated with o-phosphorylethanolamine ligands that were coupled to an o-nitrobenzyl (ONB) derivative of 5-FU. The UV photoluminescence (PL) was in resonance with the absorption band of the ONB-FU derivative and energy transfer resulted in photocleavage and subsequent release of 5-FU from the surfaces of UCNPs for these in vitro studies. Release of 5-FU was complete within minutes using a 980 nm NIR laser source that operated below 100 mW in power. The efficiency of triggered release was as high as 80% of the total conjugated ONB-FU. This work provides an important first step toward the development of a UCNP platform capable of targeted chemotherapy.

Keywords: 5-Fluorouracil
Chemotherapy
Nanoparticle
o-nitrobenzyl
Triggered
Upconverting
Advisor: Krull, J Ulrich
Re-engaging students with nature: Using local settings as a context for learning

The aim of this case study was to determine how place-based learning in a natural environment impacted disengaged students. Intermediate students at a large suburban high school were provided with an opportunity to engage in a field study that investigated a local creek. Participating students shared their knowledge with a class from a local elementary school and engaged in action that created a greater awareness of environmental issues. The results of this study indicate that place-based learning in a local forest coupled with mentoring opportunities had a positive impact on student perceptions of school and learning. In addition, findings suggest that students developed more of an understanding of ecological principles and gained a greater awareness of local environmental issues.

Keywords: environmental education
environmental literacy
experiential learning
outdoor learning
place-based education
student engagement
Advisor: Pedretti, Erminia
Serologically Active Clinically Quiescent Systemic Lupus Erythematosus: Clinical and Immunological Correlates

Aim: Some remitted systemic lupus erythematosus (SLE) patients are serologically active (by elevated anti-double-stranded DNA antibodies and/or hypocomplementemia) despite longstanding clinical quiescence ("SACQ"), thus presenting a management dilemma. We described the SACQ period and its patients, and sought biomarkers heralding disease flare in them. Methods: Patients with a prolonged SACQ period were followed prospectively, with clinical and laboratory data collected at each visit. Serologically and clinically active (SACA) and serologically and clinically quiescent (SQCQ) patients served as positive and negative controls, respectively. Descriptive statistics and logistic regression analyses were utilized.Results: SACQ patients were phenotypically unique prior to remission onset, and did not accrue subclinical organ damage over the quiescent period. Fluctuation in immunoglobulin isotype did not predict flare. The SACQ interferon and cytokine/chemokine profiles mirror SQCQ patients.Conclusions: SACQ patients' active serology should not guide treatment decisions, and these patients are best managed conservatively. Alternate biomarkers must be sought.

Keywords: Biomarkers
Epidemiology
Remission
Systemic lupus erythematosus
Advisor: Urowitz, B Murray
Modeling the Gynecologic Oncology Workforce Using System Dynamics

This research seeks to better understand the workforce needs within gynecologic oncology using health human resource planning and system dynamics modeling. Historical cancer surgeries were obtained from CIHI for 2004-2011 and forecasted for 2012-2032 using double exponential smoothing. A system dynamics model consisting of the fellowship population, aging provider population, and patient need population was developed. The model predicted that 94 new FTEs will need to be hired during 2012-2032. We assumed that in the current environment, the enrolment rate changes based on the workforce shortage or surplus, which results in an oscillating effect between these variables. Therefore, predetermining the fellowship enrolment rate should be undertaken to reduce the oscillation. Transferring follow-up appointments to nurse practitioners proved effective for reducing the workforce shortage, but more research is required into implementation. A similar approach could be used to model the workforce in other medical specialties.

Keywords: Forecasting
Gynecologic oncology
Health human resource planning
Surgical oncology
System dynamics
Workforce planning
Advisor: Carter, W Michael
Oxidative Stress in Bipolar Disorder: a Meta-analysis of Oxidative Stress Markers and an Investigation of the Hippocampus

Bipolar disorder is a prevalent and debilitating disease, however, its pathophysiology remains unknown. There is substantial evidence of oxidative damage in bipolar disorder from both peripheral and post-mortem samples, especially in the prefrontal cortex. It is the objective of this study to consolidate research measuring oxidative stress biomarkers in bipolar disorder through a meta-analysis and to determine if the hippocampus region is a specific target of oxidative damage through a biochemical study using post-mortem samples. Results from this study further confirm the presence of oxidative damage in bipolar disorder, but suggest that the hippocampus is not a target. We have also shown a global increase of 5-hydroxymethylcytosine in the hippocampus of patients with schizophrenia, suggesting a possible alteration in the demethylation pathway. Determining the exact targets of oxidative stress in bipolar disorder may lead to biomarker development, better treatment and diagnostic options, and ultimately, a better quality of life for patients.

Keywords: 5-hydroxymethylcytosine
Bipolar disorder
Hippocampus
Lipid peroxidation
Oxidative stress
Schizophrenia
Advisor: Young, L. Trevor