The Impact Of Combined Flexion And Compression On The Mechanical Integrity Of The Annulus Fibrosus, Keaton Briar

Theses and Dissertations (Comprehensive)

Introduction: Intervertebral disc (IVD) herniation is characterized by an expulsion of nucleus pulposus (NP) material through the annulus fibrosus (AF). The AF contains two major adhesive structures, the intralamellar matrix and the interlamellar matrix, which act to maintain the strength of the AF and prevent NP material migration. As a herniation occurs, clefts form within the intralamellar matrix, pushing the NP between adjacent collagen fibres; meanwhile, delamination of the interlamellar matrix causes the NP to pool between layers of the AF. Further, herniation more readily occurs in a combined loading scenario of both compression and flexion. Flexion, and in particular …

Spatial Memory And Executive Functioning In The Goto-Kakizaki Rat Model Of Diabetes, Lorielle Dietze

Theses and Dissertations (Comprehensive)

Type 2 diabetes mellitus is a disease that adversely affects cognitive function in areas extending to memory and executive functioning. The Goto-Kakizaki (GK) rat provides a model of type 2 diabetes that can illustrate the mechanisms by which this disease works. The present study compared hyperglycaemic GK rats and age-matched Wistar rats in the Morris water maze to assess spatial memory, and in a perceptual attentional set-shifting task to assess putative prefrontal-dependent executive functioning. Results showed there was no difference in path length during training trials, however, GK and Wistar rats differed in the path length travelled in the target …

Fall Reading Week: Exploring The Effects On Student Well-Being, Roobina Medhizadah

Theses and Dissertations (Comprehensive)

Mental health is a concerning issue in post-secondary institutions across Ontario. Post-secondary students are challenged with many stressors such as time management and living independently for the first time (Wagner & Rhee, 2013). In an attempt to help students, maintain or improve their mental health, universities across Ontario have implemented fall reading week, a mid-semester break (Poole et al., 2017). Previous studies (Cramer & Pschibul, 2017; Poole et al., 2017) provided mixed results in whether fall reading week positively influences student mental health and well-being. To date, few studies have explored the influence of fall reading week on student health …

Spinal Motor Neuron Excitability And Balance Control Changes Following Downslope Walking, Nikki Aitcheson-Huehn

Theses and Dissertations (Comprehensive)

Downslope walking (DSW) has been proposed as a rehabilitation tool for people with Multiple Sclerosis (PwMS) although there are mixed findings in young adults (YA) regarding the balance control changes, despite both populations experiencing depressed spinal motor neuron (MN) pool excitability. Our aim was to determine whether YAs could demonstrate improved balance control in conjunction with SOL H reflex depression (estimate of spinal MN excitability) following DSW. We also aimed to determine whether reciprocal inhibition was a potential mechanism for H reflex depression via conditioned SOL H reflexes. Thirty young adults (23±1.4y, 6 males) were assigned to 30-minutes of DSW …

A Qualitative Investigation Into The Influence Of A Mental Health Physical Activity Intervention On University Students, Heather M. Tunks

Theses and Dissertations (Comprehensive)

Objective

Among the university student population, mental illnesses are highly prevalent. Adults aged 20-30 years have the highest rates of mood and anxiety disorders than any other age group, with approximately 12.0% diagnosed with an anxiety disorder and 7.0 to 9.0% experiencing clinical depression (Nunes et al., 2014; Pedrelli, Nyer, Yeung, Zulauf, & Wilens, 2015). Reducing or preventing the effects of mental illness among this population may have lifelong implications including improvements in coping and management of mental illness throughout the lifespan(Jaworska, DeSomma, Fonseka, Heck, & MacQueen, 2016). This research examines the lived experiences of volunteers and participants in a …

What Makes An Image Memorable? Effects Of Encoding On The Mechanism Of Recognition, Asiya Gul

Theses and Dissertations (Comprehensive)

Memory is undoubtedly one of the most important processes of human cognition. A long line of research suggests that recognition relies on the assessment of two explicit memory phenomena: familiarity and recollection. Researchers who support the Dual Process Signal Detection (DPSD) model of recognition memory link the FN400 component (a negative ERP deflection peaking around 400 ms at frontal electrodes) with familiarity; however, it is currently unclear whether the FN400 reflects familiarity or implicit memory. Three event-related potentials (ERP) studies were conducted to determine whether implicit memory plays a role in setting up encoding strategies, and how these encoding strategies …

“This Is My Little World…”: Navigating The Group Exercise Experience Of Stay-Fit Members, Olivia Jones

Theses and Dissertations (Comprehensive)

Objective

Cancer is the leading cause of death in Canada, with one in two Canadians expected to develop cancer over their lifetime (Canadian Cancer Society, 2019). Exercise is reportedly a safe therapy to help ease the common side effects of cancer and its treatments (Schmitz et al., 2010). Past research has shown the benefits of group exercise while in treatment for cancer, but there is a dearth of research regarding the impact of long-term group exercise programming for cancer survivors. This phenomenological study explored the lived experiences of group exercise participation for individuals who previously had cancer and were enrolled …

Characterization Of The Microbial Phosphonate-Activating Pntc Enzymes, Kyle Rice

Theses and Dissertations (Comprehensive)

New strategies are urgently needed to combat infectious diseases in an era of rising antibiotic resistance. Furthermore, an emerging appreciation for the human microbiome’s role in maintaining health motivates discovery of species-specific antibiotics that minimally disrupt our native bacterial communities. Small molecule modifications to bacterial cell surfaces represent a potentially rich source of new targets for next generation antibiotics, as these molecules mediate virulence and evasion of the host immune response. Phosphocholine (PCho) is a rare cell surface modification that contributes to virulence, and modifications with phosphonates like 2-aminoethylphosphonate (AEP) are even more unusual and therefore provide opportunities for species- …

Charecterization Of The Innate Immune Response In The Rat Intervertebral Disc At The Tissue And Cellular Level, Matthew Guerreiro

Theses and Dissertations (Comprehensive)

Low back pain (LBP) affects up to 80% of the global population at some point during their life. The costs associated with LBP are estimated at $100 billion per year, putting significant strains on our healthcare system. As intervertebral disc (IVD) herniation is one of the major causes of LBP we decided to focus on herniation facilitated inflammatory responses, where damage caused by herniation triggers an innate immune response which likely results in pain, inflammation, and recruitment of specialized innate immune cells like macrophages to the affected area. Since the role of the inflammatory response is relatively uncharacterized in the …

Spatial Modelling And Wildlife Health Surveillance: A Case Study Of White Nose Syndrome In Ontario, Lauren Yee

Theses and Dissertations (Comprehensive)

Wildlife data is often limited by survey effort, small sample sizes, and spatial biases associated with collection and missing data. These factors can create unique challenges from a surveillance perspective when trying to extract spatial patterns of habitat suitability and disease distributions for conservation and management purposes. This thesis examined data quality from a wildlife health database in the context of spatial analysis of wildlife disease. Spatial analysis of the data to predict habitat suitability of bats and white nose syndrome afflicted bats was examined by using the MaxEnt modelling method. Methods to reduce spatial bias were examined and specific …

The Effects Of Orthotics And Increased Plantar Sole Mechanoreceptor Activation On Turning Performance In Individuals With Parkinson’S Disease, Kelly A. Robb

Theses and Dissertations (Comprehensive)

Locomotion and turning are complex movement patterns essential to activities of daily living. Individuals with Parkinson’s disease (PD) report difficulties turning, often coupled with impaired balance and increased fear of falling. The purpose of this within-subject study was to determine if orthotics, with and without a textured top cover, can improve gait stability and turning performance within Parkinson’s participants. Seven participants with a diagnosis of idiopathic Parkinson’s disease, aged 55-80 years old, participated in the study. Participants completed three testing sessions; baseline, 4 weeks post-baseline, and 5 weeks post-baseline. The ‘footwear only’ and ‘footwear + non-textured orthotic’ conditions were tested …

Structure-Function Investigation Of Proteins Involved In Cellulose Biosynthesis By Escherichia Coli, Thomas Brenner

Theses and Dissertations (Comprehensive)

Bacteria thrive within multicellular communities called biofilms consisting of a self-produced matrix. Biofilm matrices improve bacterial adherence to surfaces while creating a barrier from host immune responses, disinfectants, antibiotics and other environmental factors. Persistent colonization by the widely distributed pathogens, Escherichia coli and Salmonella spp., has been linked to production of biofilms composed of the exopolysaccharide cellulose. Cellulose-containing biofilms are also important to Acetobacter, Sarcina, Rhizobium and Agrobacterium species to form symbiotic and pathogenic interactions. In Enterobacteriaceae, two operons (bcsABZC and bcsEFG) are proposed to encode for proteins that form a cellulose biosynthetic complex that spans the …

The Effects Of A 12-Week Custom Foot Orthotic Intervention On The Intrinsic Muscles Of The Foot, And Dynamic Stability During Unexpected Gait Termination In Healthy Young Adults, Katrina Protopapas

Theses and Dissertations (Comprehensive)

Introduction: Custom-made foot orthotics (CFO’s) are a commonly prescribed intervention to help individuals that are suffering from foot pain and foot disorders. However, the mechanisms of CFO’s are still poorly understood and are not well known. With the plantar intrinsic muscles of the foot being in direct contact with the CFO, it puts these structures at risk for disuse muscle atrophy as a result of being offloaded. Therefore, the purpose of the current study was to determine the effect of a 12-week custom-made foot orthotic intervention on the intrinsic muscles of the foot and dynamic stability during unexpected gait termination. …

What Lies Past Remission: The Perceived Late Effects Of Pediatric Cancer, Monica L. Molinaro

Theses and Dissertations (Comprehensive)

Objective

Pediatric cancer survival rates are increasing (Childhood Cancer Canada Foundation, 2011) and with this, so are the late effects of pediatric cancer (Oeffinger et al., 2006). This research examines the lived experiences of the perceived long-term effects of pediatric cancer on adult survivors and their primary support persons in order to understand the multifaceted nature of the illness on adults, and how it affects others close to them.

Methods

The theoretical orientation used to guide the research was phenomenology in order to present an accurate depiction of all the participants’ lived experiences. Specifically, background questionnaires were administered and one-on-one …

The Role Of Oxidative Stress In The Mechanisms Of Ammonia-Induced Brain Swelling And Tolerance In The Goldfish (Carassius Auratus), David F. Jones Lisser Mr.

Theses and Dissertations (Comprehensive)

Toxic build-ups of ammonia can cause potentially fatal brain swelling in mammals, but such swelling is reversible in the anoxia- and ammonia-tolerant goldfish (Carassius auratus). The mechanisms of ammonia-induced brain swelling and tolerance remain elusive, but several studies have suggested a role for reactive oxygen species (ROS), which may damage proteins and lipids in the plasma membrane of astrocytes in the brain. As a result, osmotic gradients across cell membranes may be altered leading to water uptake by astrocytes and swelling. While a role for ROS has been proposed in mammals, no studies have addressed this question in …

The Effects Of External Focus Of Attention Exercise Rehabilitation On Dual Task Walking In Parkinson's Disease, Eric N. Beck

Theses and Dissertations (Comprehensive)

Parkinson’s disease impairs control of well-learned movements, and therefore, individuals with Parkinson’s disease are forced to walk with greater conscious control. This causes difficulties while walking and completing a secondary task simultaneously (dual tasking), in that distractions from conscious control of walking increase the risk of falls and injury. Although, attention-based exercise may be a potential avenue to decrease the demands associated with walking in Parkinson’s disease. For example, an external focus of attention (on manipulated objects) has been found to recruit the networks that are important for walking with little conscious control (automatic control networks). In contrast, an internal …

The Influence Of Hip Mobility And Fatigue On Spinal Flexion And Muscle Activation In Rugby Scrum Performance, Joshua D. Clayton

Theses and Dissertations (Comprehensive)

Introduction: Rugby scrumming is a means of restarting play following a minor rule infringement that can occur up to 28 times per game. The scrum poses a significant injury risk, with more days missed due to injury per event than any other rugby activity. Rugby players also have a significantly higher rate of spine injury than the general population, perhaps due to flexion in combination with high compression forces, which has been cited as the main mechanism of injury. Flexion of the spine has also been associated with poor hip mobility and quadriceps fatigue in other athletic tasks and may …

Influence Of Planning Resources On Gait Control In Parkinson’S Disease, Frederico P. Faria

Theses and Dissertations (Comprehensive)

Movement disturbances in individuals with Parkinson’s disease (PD) have been associated with difficulties to plan complex actions. Performance of simple and complex actions overloads resources for individuals with Parkinson’s disease (PD). However, it is unclear if central resources required to plan gait adjustments while walking exacerbate gait disturbances of patients with PD. More specifically, it is unclear how gait impairments, sensory processing, and the dopaminergic system influence the load on processing resources (e.g. cognitive load) during the planning of step modifications. In order to investigate the relative influence of these factors on cognitive load and its impact on gait control, …

An Athletic Approach To Studying Perception-Action Integration: Does Sport-Specific Training, And The Impact Of Injury, Influence How Individuals Visually Guide Navigation?, Carmen Baker, Jennifer Campos Ph.D, Michael E. Cinelli Ph.D.

Theses and Dissertations (Comprehensive)

The objective of this thesis was to investigate perception-action integration capabilities of individuals during a choice navigation task. This task assessed navigation strategies in open space while individuals avoided colliding with two vertical obstacles that created a body-scaled, horizontal gap, at three varying obstacle distances from the starting location (3m, 5m, 7m). The two studies completed in this thesis employed the same paradigm to assess the hypothesized group differences. Gaze behaviours and kinematics of navigation strategies were compared between: 1) athletes specifically trained in navigating in open space versus non-athletes; and 2) athletes with post-concussion syndrome (PCS) versus non-concussed, specifically …

The Effect Of Training Older Adults In Tai Chi And Compensatory Stepping On Balance Control, Hannah L. Moore Miss

Theses and Dissertations (Comprehensive)

Abstract

Introduction: In Canadian society, there is a growing prevalence of older adults and one of the main problems facing this generation today is the risk of falling. Tai Chi (TC) is a martial art that has demonstrated improvements in balance control. It uses a series of fluid movements that engage head, neck and trunk rotation while simultaneously reducing base of support. In addition, it has been demonstrated that training older adults by administering unpredictable perturbations to challenge balance better equips them to react successfully in response to balance perturbations. This study aims to determine the potential balance specific benefits …

An Exploratory Examination Of Families Engaged In An Adventure Running Kids Program, Heather Isnor

Theses and Dissertations (Comprehensive)

Academics and practitioners have only just begun to delve into the health benefits of outdoor activities in the last few years. In general, the forested settings of these activities have been documented to decrease stress levels, increase recovery rates from disease, and lessen the symptoms of mental illnesses (Kuo & Faber Taylor, 2004). It is believed that the natural environment acts as a setting where humans can engage in physical activity, aesthetic experiences, and social interactions that, in turn, release stress and lead to improved well-being (Bird, 2012). Currently, however, children are experiencing limited exposure to nature and which has …

Physical Fitness Characteristics Of An Active Firefighter Population Serving An Urban Area, Michael R. Antolini

Theses and Dissertations (Comprehensive)

Firefighters require a high level of physical fitness in order to meet the demands of their profession. While physical fitness testing is required to join the department, firefighters are not subject to further formal exercise testing throughout the duration of their careers. Active, career firefighters were tested on a variety of physical fitness measures related to body composition, strength, power, and endurance over three testing sessions. 49 firefighters (40.5 ± 8.3 yr, 89.5 ± 13.0 kg, 27.8 ± 3.6 kg/m2) were found to have a resting heart rate of 57.7 ± 8.2 bpm, blood pressure of 121.5 ± 11.9/71.5 ± …

The Effects Of 17Α-Ethynylestradiol (Ee2) On Gonadal Development And Differentiation In The Estuarine Killifish, Fundulus Heteroclitus, Ibrahim Chehade

Theses and Dissertations (Comprehensive)

Endocrine disrupting substances (EDSs) comprise a wide variety of chemicals that perturb normal endocrine function including developmental and reproductive processes in vertebrates. The synthetic estrogen 17α-ethynylestradiol (EE₂) is a commonly-used model EDS because of its environmental relevance and its effects on the reproductive endocrine system. Early life-stage exposure of fish to estrogenic EDSs causes effects such as intersex (ovotestes in males) and feminization. This study aims to confirm the period of gonadal differentiation in the estuarine killifish or mummichog (Fundulus heteroclitus) and to determine the sensitivity of gonadal development to EE₂. Artificially-regressed mummichog were spawned, and …

The Effect On Feeding And Wheel Running Behaviours Of Housing Rats In Pairs, Roison M. O'Connor

Theses and Dissertations (Comprehensive)

The effects on feeding of moving animals from individual- to pair-housing were explored in the present three experiments. Wheel access is known to result in a temporary suppression of feeding. The move to pair-housing was compared with the effect of wheel access. In Experiment l, a group of rats was moved from individual to pair-housing (IP group) and compared to a group of individually-housed rats (IND group) and a group of chronically pair-housed rats (PAIR group). The animals in the IP group showed a temporary (three days) suppression in feeding (initially 23%). When half of the IND and PAIR group …