Under-Sampled Reconstruction Techniques For Accelerated Magnetic Resonance Imaging, Mohammad H. Kayvanrad

Electronic Thesis and Dissertation Repository

Due to physical and biological constraints and requirements on the minimum resolution and SNR, the acquisition time is relatively long in magnetic resonance imaging (MRI). Consequently, a limited number of pulse sequences can be run in a clinical MRI session because of constraints on the total acquisition time due to patient comfort and cost considerations. Therefore, it is strongly desired to reduce the acquisition time without compromising the reconstruction quality. This thesis concerns under-sampled reconstruction techniques for acceleration of MRI acquisitions, i.e., parallel imaging and compressed sensing.

While compressed sensing MRI reconstructions are commonly regularized by penalizing the decimated wavelet …

Risk Of Kidney Stones In Living Kidney Donors: A Matched Cohort Study, Sonia Thomas

Electronic Thesis and Dissertation Repository

A kidney stone in a person with one kidney requires urgent attention which may result in surgical and/or hospital attention. We conducted a matched retrospective cohort study to determine if living kidney donors compared to healthy non-donors have a higher risk of: 1) kidney stones with surgical intervention, and 2) hospital encounters for kidney stones. We reviewed and linked information from pre-donation charts to Ontario healthcare databases. We selected healthy non-donors from the general population, matching ten non-donors to every donor, to generate a cohort of 2,019 donors and 20,190 non-donors. There was no difference in the rate of 1) …

Placed-Based Rural Public Health Policy, Angela M. Jurich

Electronic Thesis and Dissertation Repository

Abstract

Attention to place in public health policy development at the provincial level often overlooks the specific and unique needs of rural places. The principle aim of this research was to explore whether and how “place” was considered in the context of rural Ontario public health policy implementation for chronic disease prevention (CDP) programs. A secondary analysis of focus group and interview data along with the policy documents from three rural Ontario public health unit sites for the primary Renewal of Public Health Systems (RePHS) study was conducted. Based on a review of the literature on rural health policy and …

Word-Finding Difficulties: Exploring Tip-Of-The-Tongue States In Young And Old Adults, Allison J. Partridge

Electronic Thesis and Dissertation Repository

A Tip-of-the-Tongue (TOT) occurs when you are trying to think of a specific word but lack the ability to bring it to mind. The present study examined implicit learning processes operating under errorful (20-second delay) or errorless (0-second delay) learning conditions in TOT states. Participants included 15 young (20-30 years) and 15 old (65-88 years) adults who were tested twice a week for four weeks on a definition-word pair task. For young participants, results indicated that a TOT was more likely and older participants were more likely to indicate they did not know the word on a consecutive session after …

Development Of A Translational Animal Model Of Sepsis, Nathaniel E. Hayward

Electronic Thesis and Dissertation Repository

Sepsis is an excessive inflammatory response to infection that leads to multiple organ failure. The high mortality rates in the intensive care unit have remained stagnant, which can be attributed to the disconnect between the bench and the bedside. There is a global need for an animal model of sepsis that is more relevant to the clinical scenario. We developed an in vivo rat model of sepsis, with a high level of instrumentation, to monitor macrovascular and microvascular changes over the course of a feces-induced peritonitis (FIP) .

In addition, early fluid resuscitation of septic patients is associated with better …

The Impact Of Intrauterine Exposure To Gestational Diabetes Mellitus On Early Childhood Body Mass Index Trajectories, Aniq Anam

Electronic Thesis and Dissertation Repository

Background: Although gestational diabetes mellitus (GDM) has been linked to pediatric obesity, there is limited research on the impact of intrauterine exposure to GDM on trajectories of childhood growth. Objective: To assess the effect of prenatal GDM exposure on childhood body mass index (BMI) trajectories. Design: Analyses were conducted using data from cycles 2 to 6 (1994-2004; N=3412 children) of the National Longitudinal Survey of Children and Youth. Latent growth curve modelling (LGCM) was used to model BMI trajectories from age 2 to 10 years with prenatal exposure to GDM as a predictor. Effect modification by breastfeeding was assessed. Results: …

How Age Friendly Is This City? Strategies For Assessing Age-Friendliness, Michelle Dellamora

Electronic Thesis and Dissertation Repository

The Age-Friendly Cities framework, created by the World Health Organization (WHO), has emerged as a community-based response to the challenges of demographic aging and increasing urbanization. In 2010, London, Ontario, became the first city in Canada to join the WHO Global Network of Age-Friendly Communities. Network milestones require the measurement of the baseline age-friendliness of the community. The objectives of this thesis are: 1. Determine the best available assessment tools for measuring the age-friendliness of a community, and 2. Establish the baseline age-friendliness of London, Ontario. A scoping review was utilized to collect and assess available surveys and questionnaires. A …

The Development Of A New Dry Powder Inhaler, Xi Zhang

Electronic Thesis and Dissertation Repository

A new dry powder inhaler (DPI) for respiratory drug delivery was developed. This novel device is characterized by a micro-dose, passive delivery and multiple doses individually sealed in one replaceable disk. The micro-dose delivery system uses only a small amount of excipient, such as 2-3mg lactose, thereby improving the drug delivery efficiency. The passive delivery method eliminates the need for coordination between breath and device actuation such as the pressure metered dose inhaler (pMDI). Finally, 14 doses on a disk reduce the need to frequently change dosage disks. In addition, each dose is effectively protected by a blister package to …

Mitigating Risk Factors For Disease Progression In Patients With Varus Gonarthrosis, Angelo Boulougouris

Electronic Thesis and Dissertation Repository

Knee osteoarthritis (OA) is a leading cause of disability worldwide. Its growing burden is related to an aging population, obesity and physical inactivity. The progression of knee OA involves both biomechanical and systemic mechanisms. Known risk factors that might be altered through interventions include lower limb alignment, the distribution of loads across the knee during walking, body composition and muscular strength. The overall purpose of this thesis was to evaluate the effects of multi-modal, rehabilitative and surgical interventions that target different risk factors for disease progression in patients with medial compartment knee OA and varus mal-alignment (varus gonarthrosis). The thesis …

Academic Achievement Of Children And Adolescents With High-Functioning Autism Spectrum Disorder With In-Depth Focus On Written Expression, Heather M. Brown

Electronic Thesis and Dissertation Repository

The goal of this research was to identify areas of strength and need in the academic abilities of students with high functioning autism spectrum disorder (HFASD).

Three studies were undertaken: 1) six meta-analyses investigated whether nonverbal IQ was in accordance with academic achievement scores in the areas of reading, writing, and math for students with HFASD; 2) the narrative writing skills of students with HFASD were examined in order to describe the ways their writing may differ from their typically developing (TD) peers; and 3) the persuasive writing of students with HFASD was examined to determine whether their texts resembled …

Children At-Risk For Hearing Impairment: A Retrospective Study Of The Ontario Infant Hearing Program Population, Katherine M. Smith

Electronic Thesis and Dissertation Repository

There is widespread agreement that infant hearing screening programs are effective but such programs may fail to detect all hearing impairment and children can develop subsequent hearing loss after passing the initial screen. This is the core rationale for surveillance programs that are analyzed in this thesis. Infants with hearing risk factors are followed using surveillance programs that include monitoring by audiological assessment.

The study population in this thesis consists of 2,390 children with normal hearing and 248 children with hearing impairment from different referral routes. The Infant Hearing Program Surveillance group is 1.48% of the number of hearing-impaired children. …

Characterizing The Human Vaginal Microbiome Using High-Throughput Sequencing, Jean Megan E. Macklaim

Electronic Thesis and Dissertation Repository

The human vaginal microbiome undoubtedly has a significant role in reproductive health and for protection from infectious organisms. Recent efforts to characterize the bacterial species of the vagina using molecular techniques have uncovered an unexpected diversity. Using high-throughput sequencing I sought to describe the structure and function of the vaginal microbiome under different physiological states including healthy, bacterial vaginosis (BV), post-menopausal vaginal atrophy, and acute vulvovaginal candidiasis (VVC).

Partial 16S rRNA gene sequencing revealed that healthy, asymptomatic women most often have vaginal biotas dominated by Lactobacillus iners or L. crispatus. In contrast, BV is a heterogeneous, highly diversified condition …

Resilience As Health Promotion In Action: University Students Who Grew Up Amid Violence Directed Towards Their Mothers, Tatiana Murkin (Zdyb)

Electronic Thesis and Dissertation Repository

Abstract

Violence against women is among the greatest threats to the health of our population. An estimated three hundred and sixty thousand children in Canada, and over two million worldwide are exposed to violence in their homes (UNICEF, 2006). Growing up amidst such violence seriously compromises children’s capacities for healthy development. Violence against women is not limited by culture, geography or socioeconomic status. It constitutes one of the most pervasive and yet least openly discussed human rights violations and public health issues known today.

Researchers and allied health professionals generally agree that children whose development has been interfered with by …

Glass-Ceramics For Non-Metallic Dental Implant Applications, Selma Saadaldin

Electronic Thesis and Dissertation Repository

Metallic dental implants are an important treatment for the replacement of missing teeth. However, for esthetic and environmental issues, there is a need to develop non-metallic dental implant materials. In this thesis, two novel glass-ceramics (GCs), miserite and wollastonite, were synthesized for one-piece dental implant applications. Glasses were synthesized by wet chemical methods, followed by calcination, melting and quenching. The crystallization kinetics of these glasses were determined by differential thermal analysis (DTA). GC specimens were produced by cold pressing of the glass powder and sintering using schedules determined by DTA. The crystalline phases and microstructure of the GC samples were …

Investigating The Effects Of Custom Made Orthotics On Brain Forms: A Pilot Study, Lindsay Carey

Electronic Thesis and Dissertation Repository

OBJECTIVES: To determine (1) the feasibility of this novel approach and technique of recording brain activity, wirelessly and continuously, during human gait, and (2) if custom made orthotics will alter the brain activity patterns recorded. METHODS: Gait trials were performed on 16 participants walking with and without orthotic devices in their shoes while simultaneously collecting EEG data through the Emotiv wireless neuroheadset. RESULTS: The Emotiv neuroheadset was capable of detecting changes in brain activity between the two gait trials. The differences in brain activity identified between conditions were not statistically significant. CONCLUSION: The findings suggest the Emotiv EEG device is …

An Exploration Of Early Childhood Education Students' Knowledge And Preparation To Facilitate Physical Activity For Preschoolers, Olivia Martyniuk

Electronic Thesis and Dissertation Repository

Early childhood educators play an important role in influencing preschoolers’ physical activity levels. The current study sought to explore Early Childhood Education (ECE) students’ physical activity (PA)-related knowledge and educational experience. A total of 1,113 ECE students from 20 Ontario Colleges completed the study survey (online or on paper), which examined students’ PA course content; awareness of PA guidelines; understanding of health-related benefits of PA; self-efficacy to facilitate PA for preschoolers; as well as PA resource needs. Survey results identified that 72.1% of ECE students had not completed any PA/physical education specific courses, while only 28.7% were familiar with, and …

Exploring The Structure And Biochemistry Of Oxidation-Mediated Inhibitation Of The Peptidyl-Prolyl Isomerase Pin1, Brendan T. Innes

Electronic Thesis and Dissertation Repository

Pin1 is a phosphorylation-dependent peptidyl-prolyl isomerase that has been shown to be neuroprotective in aging-related neurodegenerative diseases such as Alzheimer's disease (AD). However, it is not active in AD brain, and a recent proteomic screen of Mild Cognitive Impairment (MCI) brain samples revealed that Pin1 is oxidized in the brains of these pre-AD patients. This suggests that this oxidation may be the cause of the loss of the neuroprotective Pin1 function in AD. The Pin1 active site contains a functionally critical cysteine residue (Cys113) with a low predicted pKa, making it highly susceptible to oxidation. We hypothesize that Pin1 is …

A Pilot Study To Investigate Concerns In Patients Undergoing Neck Dissection Surgery, Daniel Sundar Raj Arulananda Doss

Electronic Thesis and Dissertation Repository

Abstract:

This study investigates concerns in patients undergoing neck dissection surgery. Forty patients were recruited at Pre-surgery, Discharge and 1-month Post-surgery. The Patient Concerns Inventory - Level of Importance questionnaire (PCI-LOI), Shoulder Pain and Disability Index (SPADI), Neck Dissection Impairment Index (NDII) and the University of Washington - Quality of Life questionnaire (UWQOL) were used.

The study identified "Anxiety" at Pre-surgery and "Appearance" at Discharge and 1-month Post-surgery as the important patient concerns. Patients’ concerns were found to change over time. Support for cross-sectional convergent validity of the PCI-LOI was evidenced by significant correlations between the PCI-LOI and the UWQOL …

Exploring Accuracy In Journalism Stories Reporting On Neuroscience Research Findings: A Comparative Case Study, Andrea M. Campbell-Davison

Electronic Thesis and Dissertation Repository

Abstract

Neuroscience has seen explosive growth in research and public interest, but research findings are often reported inaccurately, impacting public understanding. Exploratory descriptive case study methods were used to analyze two peer reviewed research articles, one on brain imaging for patients in a Persistent Vegetative State (PVS), and another on Brain Training (BT), and all journalism stories regarding these two studies. Statistical and content analyses were used to analyze the accuracy of the translation of the research into journalism stories. PVS research received more media attention and this reporting was less accurate than for BT research; the information was also …

The Effect Of Pacing Strategies On Oxygen Kinetics And Muscle Hemoglobin Status And Energy System Contribution In A 6 Min Exercise Performance, John D. Murray

Electronic Thesis and Dissertation Repository

ABSTRACT

The purpose of this study was to compare the effects of two different pacing strategies during a 6 min exercise performance on average power output, VO₂ kinetics, deoxygenation in the vastus lateralis muscle, energy system contribution, average power output and blood lactate concentration. Eight young, healthy, male subjects (age 24 ± 3) completed two 6 min pacing strategies on a cycle ergometer; one bout was paced at a calculated fatigue threshold (FT) and the other began with a 12 s sprint and was paced 5 % below FT pace (5%2, work rate, anaerobic energy system contribution and energy …

Intermittent Hypoxia Alters Metabolic And Cardiovascular Neural Pathways, Jason Michael Moreau

Electronic Thesis and Dissertation Repository

Intermittent hypoxia (IH) is a major pathophysiological manifestation of obstructive sleep apnea (OSA). Previous studies have implicated IH in mediating many pathophysiological outcomes associated with OSA. Only few studies have examined IH-induced alterations to central signaling pathways important in cardiovascular and metabolic phenotypes associated with OSA. This thesis employed a rodent model of IH to examine changes to molecular neural pathways associated with metabolic and cardiovascular pathophysiological outcomes of OSA. Acute IH induces a specific negative body energy balance phenotype. This is concomitant to a reduction in body weight and food intake, with an elevation in food conversion efficiency. Increased …

Effects Of A Power-Line Frequency Magnetic Field On Human Cognitive Processing, Michael Corbacio

Electronic Thesis and Dissertation Repository

Extremely low frequency (ELF, < 300 Hz) magnetic fields (MFs) have been reported to modulate human cognitive performance. However, little research has investigated MF exposures comparable to the highest levels experienced in some occupations. This research evaluated the impact of a 60 Hz, 3 mT MF on human cognitive performance. Ninety-nine participants completed the double-blind protocol performing a selection of psychometric tests under two consecutive MF exposure conditions (exposure vs. no exposure). A significant interaction effect on a working memory test (digit span forward - F=5.21, p

Prenatal Programming Of Hepatic Glucose And Cholesterol Regulation In Male Rat Offspring By Chronic Intermittent Hypoxia, Waseem Iqbal

Electronic Thesis and Dissertation Repository

Obstructive sleep apnea (OSA) is a chronic disorder involving repetitive interruptions in breathing during sleep. Sufferers of OSA are exposed to chronic intermittent hypoxia (CIH), characterized by cyclical reductions in oxygen availability. A number of studies have established a link between OSA and various cardiovascular and metabolic comorbidities in adulthood, including hypertension, obesity, and type II diabetes. While the consequences of OSA in adults have been well described, the cross-generational impact of this condition and potential effects on fetal development are not known. Epidemiological and animal studies have demonstrated that physiological insults during pregnancy lead to diminished growth of offspring …

The Effective Dose Of Different Scanning Protocols Using The Sirona Galileos® Comfort Cbct Scanner, David R. Chambers

Electronic Thesis and Dissertation Repository

Introduction: Cone Beam CT imaging is prevalent in dentistry yet much is unknown with regard to how radiation dose to the patient varies between different CBCT scanners and imaging protocols. Scanner and protocol specific effective dose calculations will aid in optimizing individualized protocols for clinical applications.

Purpose: To determine the effective dose for a range of imaging protocols using the Sirona GALILEOS Comfort CBCT scanner.

Materials and Methods: Calibrated InLight nanoDot OSL dosimeters (Landauer, Glenwood, Ill) were placed at 26 select sites in the head and neck of a modified, human tissue-equivalent RANDO phantom. Effective dose was calculated using …

Examining The Shift In Occupational Identity After A Brain Injury, Mikelle Bryson-Campbell

Electronic Thesis and Dissertation Repository

Occupational identity is defined by Kielhofner (2002) as a sense of who we are as an occupational being, based on our past, current, and future occupational roles. When a life disruption occurs such as a brain injury (BI) and the disruption impacts the ability to conduct an occupation deemed meaningful an important process of transition occurs (Muenchberger, Kendall, & Neal, 2008). In turn occupational identity may shift to reflect the current health and economic status of the individual and what occupations are judged as meaningful.

The current study examined the shift in occupational identity in BI survivors in a two …

An Evaluation Of The Frankfort Mandibular Plane Angle Bisector (Fmab) Wits Appraisal In The Assessment Of Anteroposterior Jaw Relationships, Natalie Swoboda

Electronic Thesis and Dissertation Repository

An accurate anteroposterior measurement of jaw relationships is essential in orthodontic diagnosis and treatment planning. The purpose of this longitudinal study was to establish a new cephalometric Wits appraisal using a bisector of the mandibular plane angle, named the Frankfort Mandibular Plane Angle Bisector (FMAB). The FMAB was used to assess the sagittal jaw relationship in a sample of Class I individuals, and compare this measurement to the ANB angle and the Wits appraisal using the Maxillomandibular Bisector (MMB).

The data were collected from pre-treatment (T0), immediate post-treatment (T1) and two year post-retention (T2) lateral cephalograms of 61 male and …

The Effects Of Pre- And Postnatal Administration Of Propionic Acid And Lipopolysaccharide On The Behaviour Of Adolescent Male And Female Rats, Kelly A. Foley

Electronic Thesis and Dissertation Repository

The gut microbiome plays an important role in immune functioning and neurodevelopment. Altered microbiome composition, leading to short chain fatty acid, and/or immune system dysfunction has been observed in children with autism spectrum disorders (ASD). This thesis describes the developmental influence of prenatal exposure to propionic acid (PPA), a metabolic fermentation product of enteric bacteria, or prenatal exposure to lipopolysaccharide (LPS), a bacterial mimetic and product of enteric bacteria, on a range of behaviours in male and female neonatal, adolescent and adult rats. Study one evaluated the effects of prenatal PPA and LPS, and postnatal PPA, on developmental milestones in …

Interprofessional Socialization And Dual Identity Development Amongst Cross-Disciplinary Students, Hossein Khalili

Electronic Thesis and Dissertation Repository

The purpose of this study was to develop and test an interprofessional socialization (IPS) framework through assessing the impact of an IPS-based interprofessional education program on interprofessional socialization and dual identity development among health professional students. Although health professional educational programs have been successful in equipping graduates with skills, knowledge and professionalism, the emphasis on specialization and profession-specific education has enhanced the development of a uniprofessional identity, which has been found to be a major barrier towards Interprofessional Person-Centered Collaborative Practice (IPCPCP). Despite the growing acknowledgment of IPS in the current IPE and collaborative practice literature, there is a lack …

Cholesterol-Mediated Dysfunction Of Surfactant Effects Of Surfactant Protein-A And Diet-Induced Hypercholesterolemia, Joshua Qua Hiansen

Electronic Thesis and Dissertation Repository

This thesis explored the effects of cholesterol and SP-A on surfactant function in vitro, and lung function in vivo. In the first experiment, we determined whether SP-A could mitigate cholesterol-mediated surfactant dysfunction. We hypothesized that SP-A can mitigate the surfactant inhibition caused by high cholesterol. In the second experiment, we tested the contribution of diet-induced serum hypercholesterolemia to surfactant composition and the development of lung injury in rats. We hypothesized that serum hypercholesterolemia would increase the amount of cholesterol in surfactant and would cause rats to develop more severe lung injury. Our results indicate that SP-A mitigates cholesterol-mediated surfactant …

Orthodontic Retainers: A Survey Of Patient Compliance And Satisfaction, Bhavana Sawhney

Electronic Thesis and Dissertation Repository

PURPOSE

Retention is an important aspect of orthodontics, which may influence the long-term outcome and satisfaction level of patients who undergo orthodontic treatment. The objective of this study was to identify commonly used orthodontic retainers and retention protocols, and assess patients’ opinions and satisfaction levels with these regimens in relation to several pre-defined variables.

METHODS:

A 149 question survey was created with advanced skip and branching logic. The survey was administered to orthodontic patients at either the one or two year regularly scheduled retention appointment and the overall response rate was 99% (n=131). Data collection included queries on demographics, treatment …