VictorJuiz/thesis huggingface dataset:
Assessment of Flatbed Scanner Method for Quality Assurance Testing of Air Content and Spacing Factor in Concrete

The flatbed scanner method for air void analysis of concrete is investigated through a comparison study with the standard ASTM C457 manual and Rapid Air 457 test methods. Air void parameters including air content and spacing factor are determined by image analysis of a large population of scanned samples through contrast enhancement and threshold determination procedures. It is shown that flatbed scanner method is giving comparable results to manual and Rapid Air 457 methods. Furthermore, a comparison of the air void chord length distributions obtained from the two methods of flatbed scanner and Rapid Air 457 has been implemented in this research. The effect of having different settings in the scanning process of scanner method is also investigated. Moreover, a threshold study has been performed that showed the flatbed scanner method can be employed in combination with manual and Rapid Air 457 methods as a time and cost saving strategy.

Keywords: Air void analysis
Flatbed scanner
Advisor: Peterson, Karl
Processing of Tactile Stimuli in Children with Tourette Syndrome and Attention Deficit Hyperactivity Disorder: An ERP Investigation

Purpose: To investigate and characterize sensory sensitivity in Tourette syndrome (TS) through an evaluation of behaviour, perception and processing of tactile stimuli in children with TS and co-morbid Attention Deficit Hyperactive Disorder (ADHD) compared to typically developing controls (TDC). Methods: Somatosensory evoked P3 potentials were recorded in TS+ADHD and in TDC children aged 6-12 and compared at midline electrodes. Reported sensory sensitivity was measured using the Sensory Profile, while Semmes-Weinstein filaments were used to determine tactile threshold in the same area stimulated during P3 testing. Results: 13 TS+ADHD and 12 TDC were studied. TS+ADHD children reported significantly higher sensory sensitivity (p=.001) and demonstrated a significantly lower tactile threshold (p=.027) than TDC. Furthermore, the amplitude of electrophysiological responses to repetitive tactile stimuli was significantly larger in TS+ADHD (p=.0009). Conclusion: TS+ADHD children are significantly more sensitive to tactile stimulation than controls. ERP differences suggest that central processing alterations could mediate sensory hypersensitivity.

Keywords: Tourette syndrome
ADHD
sensory sensitivity
sensory phenomena
ERP
P300
sensory
threshold
Attention Deficit Hyperactive Disorder
Advisor: Sandor, Paul
Nutrient Availability in the Rhizosphere of Coffee: Shade-tree and Fertilization Effects

Shade tree incorporation is beneficial in coffee cropping systems under sub-optimal conditions. This study was performed in lowland Costa Rica, at a 12-year-old experimental coffee farm. The main objective was to compare the effect of a nitrogen fixing shade tree, Erythrina poeppigiana, on nutrient availability in the rhizosphere of coffee under conventional fertilization. Accumulation of nutrients (mineral N, available P, and exchangeable base cations) in rhizosphere relative to bulk soil was greater under shade than full sun. Low nitrate availability in rhizosphere soil of full sun coffee was explained by root-induced acidification relative to bulk soil, as abundance of ammonia-oxidizing bacteria (AOB), which mediate nitrification, were positively correlated with pH. Organic fertilization enhanced AOB abundance and altered soil bacterial community structure relative to conventional fertilization. This study indicates clear effects of shade-tree presence on nutrient availability at the micro-scale, management of which is critical for stability of coffee agroforestry systems.

Keywords: Coffee
Agroforestry
Rhizosphere
Nutrient dynamics
Real-time PCR
Advisor: Isaac, Marney E.
Disclosure of Safety Incidents Involving Pediatric Patients: A Review of Federal, Provincial, and Territorial Legislation and Related Policies of Health Care Organizations Providing Care to Pediatric Patients

Law and health policy converge with pediatric patient safety incident (PPSI) disclosure. Disclosure is vital for patient safety efforts, while respecting the decision-making autonomy of pediatric patients involves balancing parental and legal obligations with the developing independence of children. This study examined legislation potentially relevant to PPSI disclosure, along with disclosure policies from organizations providing pediatric care. Health professionals have limited legislative guidance for disclosing PPSIs and developing institutional policies. Relevant legislation is complex and varies between jurisdictions. Three jurisdictions legislatively require disclosure, including PPSI disclosure to substitute decision makers. In jurisdictions without disclosure legislation, guidance may be obtained from other legislation, including consent and capacity, substitute decision making, and child welfare. Organizations in jurisdictions with disclosure legislation may be more likely to have policies. Such policies vary between organizations. Within the policies reviewed, PPSI disclosure is based on capacity, made to a substitute decision maker, or not addressed.

Keywords: Pediatric
Patient Safety
Disclosure
Patient Safety Incidents
Law
Legislation
Advisor: Deber, Raisa Berlin
Predictors of Muscle Function in Hemodialysis Patients

Decreased skeletal muscle function (MF) is ubiquitous in hemodialysis (HD) patients and linked to functional decline. Serum vitamin D (25-OHD) and habitual physical activity (PA) are decreased in HD and linked to reduced MF in other populations. The associations between 25-OHD, PA, and MF were investigated in 81 stable HD patients. PA intensity was quantified using accelerometery, MF using handgrip strength dynamometery, 25-OHD via serum measures, and dietary and supplementation of vitamin D intake via three-day food records. MF correlated with PA (r =0.411, p = 0.003) when controlled for body mass (BM) and with 25-OHD (r =0.298, p = 0.023) when controlled for BM, age, and sex. Both MF (r=0.285, p=0.025) and 25-OHD (r=0.314, p=0.005) correlated with vitamin D supplementation. MF remained correlated with supplementation after controlling for 25-OHD (r=0.269, p=0.037). These findings should be further explored in interventional studies to assess how their manipulation influences MF in HD.

Keywords: Exercise
Physiology
Nutrition
Dialysis
Hemodialysis
Chronic Kidney Disease
Kidney
Physical Activity
Physical Function
Muscle
Handgrip
Dynamometer
Accelerometer
Food Record
Nutrition Analysis
Vitamin D
Strength
25-OHD
Advisor: Amara, Catherine
Neuropsychological Outcome following Cranio-spinal Radiation in Medulloblastoma Patients: A Longitudinal Analysis of Predictors

Medulloblastoma is the most common malignant central nervous system (CNS) tumor in childhood. The cranio-spinal radiation (CSR) required to treat this disease results in long-term cognitive and neurologic impairments. Medulloblastoma was recently categorized into four genetic subgroups (WNT, SHH, Group 3, and Group 4). This study examined neuropsychological and intellectual functioning in 91 medulloblastoma patients (41 Group 4; 20 Group 3; 18 SHH; 12 WNT) following treatment, and examined the impact of several medical, treatment and demographic factors on functioning over time. Longitudinal growth curve analyses revealed hydrocephalus most clearly predisposes to poor neuropsychological functioning. Results also indicate medulloblastoma subgroups have heterogeneous intellectual outcomes following treatment. All subgroups experience intellectual declines following treatment; however, comparing between subgroups revealed Group 4 performs most poorly, and Group 3 has the best overall intellectual outcome. Lastly, qualitative analyses suggest treatment with a larger CSR dose may contribute to poor intellectual functioning.

Keywords: Medulloblastoma
Neuropsychology
Pediatric
Advisor: Mabbott, Donald
Exploration of Peptide Recognition using Directed Evolution of the PDZ Domain Fold

The PDZ domain family is one of the most abundant peptide recognition modules in metazoan proteomes. Characterization of natural PDZ domains has provided insight into the structural basis and diversity of peptide recognition by this fold. In order to test the limits of the current model, I evolved synthetic PDZ domains. Based on the Erbin PDZ domain and selected for binding to pep- tides with different position-2 residues, synthetic variants were characterized using high throughput peptide profiling. This approach generated insight into subclass specificities in the most common natural specificity classes (I [ST]-2 and II Φ-2), demonstrated an alternative basis for a rare specific- ity (Class III D-2) and predicted that some natural domains may exhibit an easily-evolved novel specificity (Class IV R-2). These results also emphasize that some non-contact residues may have a disproportionate effect on position-2 specificity, contrary to the predictions of the original model.

Advisor: Sachdev, Sidhu
Publicly Funded Dental Care in Ontario: Rationing Principles and Rules

Objective: To identify principles and rules used by stakeholders in making limit-setting decisions for publicly funded dental care. Methods: A purposive sample, including administrators, academics, funders, clinicians and community representatives was surveyed using a 28-item questionnaire, in the first round of a proposed three-round modified Delphi study. Using open and closed-ended questions participants made and explained decisions on prioritizing populations and services. Open-ended text was analyzed with a thematic qualitative approach using open and axial coding. Results: Consensus emerged on two rationing principles; achieving equity and providing essential care. Rules for eligibility were defined as the inability to pay and/or assume full personal responsibility for securing dental care. Inclusion/exclusion of treatment categories rested on relieving pain/infection, preventing disease and maintaining/restoring function. Conclusions: Stakeholders presented principles and rules that suggest extending the distribution of publicly funded dental care to include, at a minimum, essential services for those unable to afford care.

Keywords: rationing health care
publicly funded dental care
Advisor: Quiñonez, Carlos
Hypoglycemic Seizures in Juvenile Rats: Acute Mortality is Associated with Severe Seizures in Diabetic and Non-diabetic Subjects

Iatrogenic hypoglycemia is a limiting factor for managing diabetes mellitus and can have severe outcomes such as seizures and coma. Although several studies have investigated the central nervous system consequences of hypoglycemia, the effects of seizures, as well as possible treatment strategies, have yet to be elucidated in juvenile animals. The objective of this thesis was to establish an in vivo model of severe hypoglycemia and seizures in juvenile diabetic and non-diabetic rats. In both groups there existed a similar blood glucose threshold for seizures, and mortality only occurred following severe seizures, particularly with repeated seizures that were unresponsive to treatment. While the administration of anticonvulsants temporarily mitigated seizures, glucose administration was required to prevent mortality. Abnormalities in the hippocampal and brainstem electroencephalograms (EEG) were observed in hypoglycemic animals without a clear correlate to convulsive activity.

Keywords: Hypoglycemic seizure
juvenile diabetes
EEG
Advisor: Carlen, Peter Louis
Active Hedgehog Signaling Regulates Renal Capsule Morphogenesis

The renal capsule is a flattened layer of cells which surround the kidney. Expression of the transcription factor Foxd1 is required for normal development of the capsule. Furthermore, current evidence suggests that during development the capsule progenitors are in a state of active hedgehog signaling. We hypothesize that hedgehog plays a role in modulating capsule morphogenesis in the embryonic kidney. To test the hypothesis hedgehog signaling was inhibited in the capsule via Foxd1Cre mediated deletion of Smoothened (Smo), the activator of the pathway. Mutant kidneys were approximately 48% smaller in volume and had a 42% decrease in nephron number. Furthermore, mutants displayed abnormal patterning of the capsule where regions on the surface of the kidney had no capsule cells. The discontinuous capsule phenotype was observed only after E13.5. Additionally, capsule cells progressively lost expression of known markers Foxd1 and Raldh2 and their proliferative capacity was decreased by 54% at E13.5.

Keywords: developmental biology
kidney development
renal capsule
stroma
Advisor: Rosenblum, Norman D.
Effects of a Feedback-reward System on Speeding and Tailgating Behaviours

This thesis investigates the effect of a feedback-reward system on speeding and tailgating behaviours. Data utilized in this study were collected from 37 participants through a field trial commissioned by Transport Canada. In this trial, a feedback-reward system was investigated, which provided feedback and rewards to the drivers based on speed limit compliance and safe headway maintenance. The trial consisted of three phases: baseline, intervention, and post-intervention. During the intervention phase, real-time feedback was provided on an in-vehicle display. Participants also accumulated reward points and could view related information on a website. Results indicate that the intervention resulted in a significant increase in speed limit compliance, and this positive effect, although dampened, was still apparent after system removal. Similarly, results on headway compliance rate indicate a positive intervention effect, however, this effect did not sustain after system removal. These findings have implications for developing better aids to improve driving behaviour.

Keywords: Driving behaviour
Feedback
Speeding
Tailgating
Headway
Speedlimit
Reward
Incentive
Driving
Advisor: Donmez, Birsen
Wastewater Contaminant Sorption and Dissolved Organic Matter Characterization

Irrigation using reclaimed wastewater can introduce organic contaminants and dissolved organic matter (DOM) to soils. Sorption of three common organic wastewater contaminants to five soils of diverse organic matter composition was studied both before and after the removal of soil carbohydrate and peptide components using acid hydrolysis. Results suggest that these polar components may block organic contaminants from accessing higher affinity sorption sites in soil organic matter. The sorptive fractionation of DOM by three mineral soils was studied to assess the terrestrial fate of this complex environmental matrix. Carboxyl- and aromatic-containing moieties appear to preferentially and reversibly sorb to mineral soils. Conversely, carbohydrate and peptide components of DOM preferentially remain in the aqueous phase while aliphatic moieties were selectively retained only by a soil with high surface area. This thesis illustrates that reclaimed wastewater should be applied to soils cautiously as it may degrade soil and groundwater quality.

Keywords: organic contaminants
dissolved organic matter
sorption
organic geochemistry
soil
soil organic matter
Advisor: Simpson, Myrna J.
The Expression and Regulation of CYP2D in a Monkey Model of Ethanol and Nicotine Exposure

CYP2D6 metabolizes a range of centrally acting drugs, neurotoxins, and endogenous neurochemicals. Higher levels of brain, but not liver, CYP2D6 have been identified in alcoholics and smokers, suggesting exposure to ethanol and/or nicotine may induce brain CYP2D6. We investigated the independent and combined effects of chronic ethanol self-administration and nicotine treatment on CYP2D expression. METHODS: Monkeys were randomized into 4 groups of 10/group consisting of a control group, ethanol-only group, nicotine-only group, and a combined ethanol and nicotine group; treatments occurred for 64 days. RESULTS: Exposure to chronic ethanol and nicotine induced CYP2D across various brain regions and cell types, particularly when both drugs were given in combination. No changes in protein levels were observed in liver or in CYP2D mRNA levels in liver and brain. CONCLUSIONS: Ethanol and nicotine increase brain CYP2D levels, which may affect CNS drug response, neurodegeneration and personality among those exposed to alcohol and/or nicotine.

Keywords: CYP2D6
Nicotine
Ethanol
African green monkey
Induction
Brain
Liver
Smokers
Alcoholics
Parkinson's disease
Personality
Brain drug metabolism
Advisor: Tyndale, Rachel
Characterization of the Minimalist Hybrid Protein Inhibitor ME47 as a Potential Anti-tumour Agent Designed to Target Myc Activity in Cancer

Effective therapeutics are urgently needed to improve the treatment and survival of cancer patients and we believe that targeting the MYC oncogene would fill this gap. Our strategy to achieve this goal involves the design of minimalist hybrid protein inhibitors (MHP) - 25-75 amino acid proteins composed of subdomains of known transcription factor families to generate hybrids that act as structural competitive inhibitors of the Myc/Max:DNA E-box interaction. We have established cell systems, reagents and assays using our prototype MHP, ME47 to evaluate the biological effectiveness of this putative inhibitor as well as subsequently designed MHPs using cell-based proliferation and transformation assays. Omomyc was included as a proof-of-concept control to optimize our systems and gauge the performance of ME47. This research demonstrates for the first time that ME47 exerts desirable biological effects in human cells lines and provides support for the validity of our MHP strategy thus warranting further investigation.

Keywords: Myc
Omomyc
Max-E47
Cancer
Advisor: Penn, Linda Z.
A Look at Model Uncertainty in the Evaluation of Commodity Contingent Claims: A Practitioner's Guide

Model uncertainty in financial markets is prevalent by the very nature of how models are constructed and used by financial practitioners. As such, a proper characterization of model uncertainty should be paramount in the eyes of every practitioner, and furthermore, a proper framework for implementing such a characterization towards financial activities should be implicit. While model uncertainty is acknowledged by practitioners, a cohesive and robust framework for determining a model uncertainty risk measure that is broadly accepted by practitioners is missing. We acknowledge this deficiency and provide a practitioner's guide for evaluating a modern characterization of model uncertainty, specifically that of Li and Kwon, as applied to a subset of derivative related calculations, with the goal of promoting its implementation by practitioners. We promote its implementation by demonstrating the utility and flexibility of such a characterization relative to another modern model uncertainty risk measure, specifically that of Cont.

Keywords: uncertainty
commodity
Advisor: Kwon, Roy H.
Analysis of District Heating Potential in Toronto Using Geographical Information Systems

New district heating systems in Toronto have the potential for significant financial and environmental gains. Through the use of Geographical Information Systems (GIS) and the data required to estimate heating loads, heat maps were generated on a building-by-building basis for over 4400 buildings at nine different intersections in Toronto. School locations and planned construction maps were used to enhance the data and demonstrate the benefit of considering factors beyond finance and the environment. Out of the intersections studied, Yonge and Eglinton; Yonge and Sheppard; and Yonge and Empress held the largest heating loads. Individual building data allowed for plant locations to be suggested based on their proportional distance to the highest loads. GIS allowed for the visualization of the vast quantity of data. The opportunities for improvement include increasing the availability of location-based data and the application of the methodology to other areas of infrastructure planning and decision making.

Keywords: district heating
toronto
energy efficiency
GIS
geographical information systems
sustainability
Advisor: Karney, Bryan William
An Economic Evaluation of Conception Strategies for Heterosexual Serodiscordant Couples with HIV-positive Male Partners

An economic evaluation of the three interventions to conceive without the sexual transmission of HIV between heterosexual, HIV-discordant couples with positive male partners can inform policy decisions to subsidize pregnancy planning in this setting, as there is currently no coverage as such in Ontario. A decision tree and Markov model were designed to determine the short and long-term outcomes of unprotected intercourse restricted to timed ovulation (UIRTO), sperm washing with intrauterine insemination (SWIUI), and unprotected intercourse restricted to timed ovulation with pre-exposure prophylaxis (UIRTO-PrEP). In the short-term, UIRTO was the most cost-effective strategy. In the long-term, cases of negligible HIV transmission risk determined UIRTO-PrEP as the preferred option, while SWIUI was the choice method when this risk was high. There remains a viable risk of HIV transmission between discordant couples during attempts to conceive that require the concurrent and subsidized use of UIRTO-PrEP or SWIUI to protect against HIV infection.

Keywords: cost-effectiveness analysis
cost-utility analysis
markov model
HIV
conception
Advisor: Loutfy, Mona
Coyte, Peter C.
The Association between Metformin Therapy and Mortality Following Breast Cancer: A Population-based Study

Metformin has been associated with a reduction in breast cancer incidence, however its effect on mortality following cancer has not been adequately examined. The purpose of this study was to evaluate the impact of metformin therapy on mortality in women with breast cancer. Using Ontario health databases, this retrospective cohort examined the impact of metformin on mortality among women aged 66 years or older with diabetes and breast cancer. After a mean follow-up of 4.5 years, there was no association between cumulative metformin use and either all-cause or breast cancer-specific mortality (HR 0.97, 95% CI 0.92-1.07; HR 0.91, 95% CI 0.81-1.03 respectively per additional year of cumulative metformin use). Though metformin was not associated with a reduction in mortality in our study of older women with breast cancer, there is still a need to examine whether metformin has an effect on mortality in other breast cancer populations.

Keywords: General 0566
Advisor: Rochon, Paula A.
Sources of Spatial Variation in Herbivory and Performance of an Invasive Non-native Plant, Common Burdock (Arctium minus)

The herbivory experienced by non-native invasive plants may depend on their local environments, such as herbivore abundance. In this study, I performed a common garden experiment with plants sampled from 11 populations of Arctium minus, from southern Ontario to near its northern range limit. I also compared performance and herbivory of burdock in open and understory habitats. Finally, I conducted freezing tolerance experiments with the lepidopteran seed predator Metzneria lapella, and palatability tests with plants from different populations. Results suggested that the previously described latitudinal trends in herbivore damage among populations are due to environmental differences rather than genotypic differences among populations. At a local scale, plants of open habitat were less damaged and had better performance than understory plants. Burdock has not escaped damage by herbivores in its invaded range; instead variation among sites in herbivore populations and impacts may significantly affect the invasiveness of this species.

Keywords: Herbivory
Invasive Species
Species Ranges
Advisor: Kotanen, Peter M.