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Walking Assist Exoskeletons are wearable devices that can allow individuals with mobility impairments to maintain their autonomy. The growing elderly population has benefited from these devices by receiving assistance at joints where their muscle function has declined. Typically, the primary objective of these exoskeletons has been to reduce the metabolic cost of walking, allowing users to walk for extended periods of time while reducing fatigue. However, this strategy does not directly address the growing concern that seniors are at an increased risk of falling and sustaining severe injuries due to falls. Gait and balance disorders are among the most common causes of falls in the elderly. As the Canadian population ages, it is increasingly important to investigate the musculoskeletal changes contributing to frontal-plane instability, as mediolateral and posterolateral falls are correlated with higher incidences of severe injuries. Specifically, the hip abductor and hip adductor muscles are essential in maintaining balance in the frontal plane, yet little research has been conducted on the effect of hip abduction-adduction exoskeleton assistance on the stability of elderly individuals. This thesis investigates the effect of introducing an assistive torque with a specific magnitude, timing, and location (i.e. applied to one or both legs) on the margin of stability of elderly individuals using the OpenSim biomechanics software. Simulations of four elderly subjects were conducted while the subjects stood in a quiet standing position with both feet on the ground. A lateral perturbation force of magnitude 5%, 10% or 15% of bodyweight was applied to the pelvis of each subject. The simulations were designed to provide elderly subjects with contralateral (i.e. the limb on the opposite side of the body as the perturbation), ipsilateral (i.e. the limb on the same side as the perturbation), or bilateral hip abduction-adduction assistive torque from a hip exoskeleton device after a perturbation force was applied to the pelvis. The simulated actuators mounted at the hip joints were massless, applied torque in the frontal plane, and could generate torque instantaneously based on user-defined inputs. The change in margin of stability was used to measure the effectiveness of each assistive strategy and for comparison across all subjects. The results of this study suggest that, as the perturbation magnitude increases, the hip abduction-adduction assistive exoskeleton should prioritize assistance applied to the contralateral limb. Regardless of the perturbation magnitude, each assistive strategy that was simulated (i.e. contralateral, ipsilateral and bilateral assistance) was able to improve the margin of stability. The greatest mean improvement on the margin of stability compared to the unassisted condition occurred when using the contralateral assistance strategy. For the 5%, 10% and 15% bodyweight perturbations, a contralateral assistance of 0.75 N·m/kg (torque normalized by the subject's mass) resulted in an improvement in the margin of stability of 13.1 ± 0.987 mm, 13.0 ± 0.946 mm and 13.1 ± 0.816 mm, respectively. The simulations also suggested that similar improvements on the margin of stability were experienced at smaller assistive torque magnitudes when the actuators provided torque to the body quicker following a perturbation. The results of this study can be used by exoskeleton designers to guide their decisions when developing abduction-adduction assistive exoskeletons that target mediolateral stability assistance in the elderly population.

The purpose of this study was to examine the relationships between family differentiation, family recreation and symptoms of eating disorders. The Family Intrusiveness Scales, the Perceived Social Support from Family, the Family Leisure Activity Profile and the Eating Attitudes Test were used. Participants were students at two large universities, one in the East and one in the West. Data were analyzed using correlation and ANCOVA. Findings supported the hypothesis that a positive relationship exists between family leisure involvement and family differentiation. In addition, a negative relationship between family differentiation and symptoms of eating disorders for individuals whose parents are not in their first marriage was indicated by the results.

The purpose of this study was to determine the reliability of sixteen balance tests in individuals with Down syndrome (DS). The following tests were performed on 21 participants with DS, aged 5-31 years of age; standing test on firm and soft surfaces with the eyes opened and closed, a balance subset of the Bruininks-Oseretsky test, full turn, timed-up-and-go test, forward reach, and sit-to-stand. Each participant completed all 16 assessments twice on one day and then again on a subsequent day for a total of four trials. Seven tests had reliability coefficients greater than 0.55; one-leg stand on floor (0.76), on balance beam with eyes opened (0.62) and eyes closed (0.69), heel-to-toe walk on balance beam (0.63), straight line walk on floor (0.57), and CGS on firm (0.63) and soft (0.86) surfaces with eyes opened. We recommend these seven tests for use in clinical and non clinical settings.

PURPOSE/BACKGROUND: Cryotherapy is commonly used in physical therapy with many known benefits; however several investigations have reported decreased functional performance following therapeutic application thereof. The purpose of this study was to determine the effect of cryotherapy applied to the ankle on static and dynamic standing balance. It was hypothesized that balance would be decreased after cryotherapy application. METHODS: Twenty individuals (aged 18 to 40 years) participated in this research project. Each participant was tested under two conditions: an experimental condition where subjects received ice water immersion of the foot and ankle for 15 minutes immediately before balance testing and a control condition completed at room temperature. A Biodex® Balance System was used to quantify balance using anterior/posterior (AP), medial/lateral (ML), and overall balance indices. Paired t-tests were used to compare the balance indices for the two conditions with alpha set at 0.05 a priori. Effect size was also calculated to account for the multiple comparisons made. RESULTS: The static balance indices did not display statistically significant differences between the post-cryotherapy and the control conditions with low effect sizes. Dynamic ML indices significantly increased following the cryotherapy application compared to the control exhibiting a moderate effect size indicating decreased balance following cryotherapy application. No differences were noted between experimental and control conditions for the dynamic AP or overall balance indices while a small effect size was noted for both. CONCLUSIONS: The results suggest that cryotherapy to the ankle has a negative effect on the ML component of dynamic balance following ice water immersion. CLINICAL RELEVANCE: Immediate return to play following cryotherapy application is cautioned given the decreased dynamic ML balance and potential for increased injury risk. LEVEL OF EVIDENCE: 3b Case-control study.

Due to changes in workforce structure, household structure and the nature of jobs, today's working adults face the challenge of balancing their work and life. However, employees do not only passively react to the incompatible demands from work and life - they are active agents who make decisions about their own total life. For example, individuals make decisions about the amount of energy that they spend on work/life (WL) activities. Thus, I write three essays to understand the antecedents and consequences of employees' personal resource allocation decisions. In the first essay, I study the decision itself. That is, I identify and examine four profiles of employees' WL behavioral involvement. The studied behaviors include job behavioral involvement, organizational citizenship behavior, and life involvement. In Essay 2, I examine the antecedent of the behavioral involvement decisions – WL value, which is expressed as centrality, importance, and priority. Although an individual's behavior is argued to be directed by value, it cannot be fully understood without considering the context. Thus, I examine the influences of three external factors, including financial pressure, job demands, and perceived organizational supportive culture, on the value-behavioral involvement relationship. In Essay 3, I focus on the consequences of individuals being involved in different combinations of WL behaviors. Based on the conservation of resource (COR) theory, I argue that individuals who allocate a great amount of resources to life are more likely to utilize WL benefits offered by the organization. Furthermore, understanding work-life balance (WLB) as a psychological construct, I argue that when an individual's behavioral involvement is consistent with their WL value, he or she is more likely to experience satisfaction with regards to his or her WLB.

This study was designed to determine the effects of stage of lactation and subsequent energy status on metabolic and endocrine measures, follicular development, and the quality of oocytes obtained from Holstein cows. Holstein cows were selected prior to calving and assigned to the early lactation (EL) group (n=8) while, cows at d 90 postpartum were selected for the mid-lactation (ML) group (n=7). Blood samples were taken twice weekly from 4 wk prior to the start of follicular aspirations and then on through the aspiration periods for metabolite and hormone determination. Ultrasound-guided transvaginal follicular aspiration (TVFA) was conducted twice weekly for a 10-wk period on all cows. Follicular fluid samples were obtained from the largest follicle, > 10 mm in diameter, for hormone determination. All data were analyzed by ANOVA, using the general linear model procedures. Mean energy balance was positive for (2.43 ± 0.32 Mcal/kg) for ML cows and negative (-1.55 ± 0.33 Mcal/kg) for EL cows. In ML cows serum progesterone (P4) decreased rapidly from 2.7 ± 0.1 ng/ml at the first aspiration session to a nadir of 0.33 ± 0.1 ng/ml at wk 8, while follicular fluid P4 increased from 0.9 ± 0.5 to 5.6 ± 0.5 ng/ml. In the EL cows serum and follicular fluid P4 remained relatively constant over the course of aspirations. There was a linear increase in follicular fluid insulin-like growth factor I (IGF-I) for EL and ML cows, however the increase was more rapid for ML cows (159 ± 36 to 200 ± 36 ng/ml) than for EL cows (145 ± 36 to 164 ± 36 ng/ml). Over the aspiration period nonesterified fatty acids (NEFA) declined rapidly for the EL cows (0.32 ± 0.2 to 0.22 ± 0.2 mEq/L), while serum NEFA for the ML cows were relatively stable (0.19 ± 0.2 to 0.22 ± 0.2 mEq/L). The number of follicles observed during the aspiration sessions increased linearly for both EL and ML cows (P < 0.05) over the 10-wk period. However, the increase was larger for the ML cows than for the EL cows, going from 14.2 ± 0.5 to 18.1 ± 0.5 and 14.9 ± 0.3 to 15.7 ± 0.5, respectively. These results show that cows in early lactation are physiologically under more production stress than cows in mid lactation. Furthermore, increasing levels of serum and follicular fluid IGF-I in mid lactation may reflect differences in follicle and oocyte measures. / Master of Science

Over the past century, the role of the vice presidency has increased drastically, to the point that some view the president and the vice president as a co-presidency. When this started and who perpetuated the change is up to debate, but the fact that the vice presidency and the vice-presidential selection process have increased in visibility and importance is not. This project analyzes the changes that occurred in the selection of the vice-presidential running mates in the last four decades by comparing the news coverage of the vice-presidential selection process in the years 1968 and 2000. What characteristics (such as ideology, compatibility, moral character, experience, etc.) do the media value most when reporting on the vice-presidential selection? The study observes the presidential election-year months of March through December in order to acquire data from the time the veepstakes speculation starts—after a presidential candidate secures enough delegates to win the nomination—to after the general election—where the electoral impact of the vice-presidential choice can be interpreted. / Master of Arts

No / Convergence properties are established for the piecewise linear heat balance integral solution of a benchmark moving boundary problem, thus generalising earlier results [Numer. Heat Transfer 8 (1985) 373]. A convergence rate of O(n¿1) is identified with minor effects at large values of the Stefan number ß (slow interface movement). The correct O(n¿1/2) behaviour for incident heat flux is recovered for ß ¿ 0 (pure heat conduction) as previously found [Numer. Heat Transfer 8 (1985) 373¿382]. Numerical illustrations support the theoretical findings.

As adults age, skeletal muscles become smaller and weaker, which can ultimately lead to declines in physical function and disability. In general, older adults produce less isometric force and dynamic power than younger adults. The effects of this weakness are amplified following a series of muscle contractions that result in muscle fatigue. Since daily routines consist of repeated series of activity followed by rest, it is important to understand how muscle recovers from fatigue. In particular, muscle power has been shown to be related to physical function and balance. Thus, understanding the process of recovery from muscle fatigue will help in preventing declines in physical function in older adults. This dissertation consisted of two studies designed to understand how muscle recover following fatigue and the implications of that recovery on physical function. Study one examined recovery from muscle fatigue following a constrained task. Young and older adults were fatigued to a similar degree using a dynamometer, and recovery of power at 4 velocities, central activation, pre-motor signaling, neural efficiency and contractile properties were recorded over an hour. To evaluate the functional implications of the recovery, ratings of perceived exertion were collected and the amount of fatigue following a second fatigue bout was also recorded. The second study associated changes in physical function and balance with power following an ecologically-relevant fatiguing exercise. Following a 30 minute treadmill walk, chair rise time and balance were measured during the period of recovery from this task. As a result of fatigue, we saw increased power loss at high-velocities that did not recover over the course of an hour in older adults. . This finding was concurrent with other velocity specific changes in rates of force development, muscle acceleration, and pre-motor neural signaling. Functionally, we saw an increased in perceived effort during contraction in older adults, and an increased fatigue during a second fatigue bout. While chair rise didn't differ as a group with fatigue, there was a significant relationship with loss of high-velocity power and change in chair rise time over the hour recovery period. Balance declined immediate post-fatigue but appeared to recover to a point of greater stability over an hour. This dissertation provides novel insight about alterations in the recovery process following an acute bout of muscle fatigue, and ultimately provides data that may be useful for developing strategies to prevent disability in older adults.