Oxygen consumption remains elevated above resting values for a variable period of time after exercise. Exercise intensity and duration, food intake, laboratory conditions, metabolic measurements, gender and age are all major factors affecting the duration and magnitude of excess post-exercise oxygen consumption (EPOC). In the present study, the influence of age on EPOC was studied in men of various fitness levels. Various metabolic measurements were collected for three distinct age groups, 18-25, 35-45, and 55-67 at rest and during exercise at 60% of maximal oxygen consumption until 200 ± 10 kilocalories were expended. Immediately after the exercise bout, subjects walked on the treadmill for one minute and then were seated until oxygen consumption returned to within .01 liters of the recorded resting values.Percent body fat, V02 max and exercise V02 were significantly different between age groups. The duration (23-25 minutes) and magnitude (7-11 kilocalories) of EPOC did not differ significantly between groups. However, heart rate and minute ventilation were significantly elevated above resting measurements when V02 reached resting values. In conclusion, the physiological differences associated with the aging process were not found to significantly affect the duration and magnitude of EPOC. / School of Physical Education

<p> The purpose of this project was to demonstrate whether a multifaceted quality improvement intervention program would improve hand hygiene compliance of healthcare providers (HCPs) in the Emergency Department (ED). A descriptive design with an observational approach was used with a convenience sample of ED healthcare personnel at a large, 500 bed community hospital. Seven hundred and fifty-eight hand hygiene compliance direct observations were collected during 3 time periods (baseline, pre-intervention and post-intervention observation periods). Descriptive and inferential statistics were used to analyze differences in hand hygiene compliance across the observation periods and by HCP job category. </p><p> The results indicated a statistically significant increase in hand hygiene compliance among all groups combined after a multifaceted intervention program was implemented. Efforts to change behavior, lifestyle and the environment must be varied and the target audience must be involved to be effective. This model can be applied to HCPs in other healthcare settings to improve compliance with hand hygiene, a fundamental infection prevention practice to prevent healthcare acquired infections.</p>

<p><i>Bone Garden</i> is a collection of poetry that inspects interpersonal communication and an often misguided sense of connection with others. Through investigations of memory, disaster, aging, and gender, the collection depicts a world in which many of us fruitlessly search for empathy and a sense of solidarity. Leading this investigation is a narrator whose frustrations with isolation often result in passive aggressive behavior or violence that furthers her separation from others. <i>Bone Garden</i> proposes solidarity as a salted plot and despair as the bitter fruit harvested by those who believe in it. </p>

To investigate the possible changes in pyruvate oxidation during the rapid growth period in an animal model, the oxidation of radioactive labeled pyruvate was measured in mitochondria isolated from the gastrocnemius muscle of Sprague--Dawley rats between 4 and 16 weeks of age. The influence of the fatty acid derivative palmitylcarnitine, as an inhibitor of pyruvate oxidation, was also tested.The gastrocnemius muscle was removed from anesthesized animals at 4, 8 and 16 weeks of age. Isolated mitochondria from the muscle samples were incubated with C1--14C] pyruvate and E1-14C] pyruvate + palmitylcarnitine in a KC1 medium. The decarboxylation of pyruvate was measured by the evolution of radioactive labeled carbon dioxide. Pyruvate oxidation significantly (p .; 0.0001) increased from ages 4 to 16 weeks. The initial low rate of pyruvate oxidation was attributed to the residual metabolic effects of the pre-weaned animal' high-fat diet. The subsequent increase in the capacity of pyruvate oxidation was then explained by the shift in the animaldiet to high-carbohydrate lab chow. These results may also be attributed to the maturation of the hindlimb muscle fibers during this period: the differentiation of predominately red, oxidative fibers to an increase in the percentage of white, glycolytic fibers, common in the adult hindlimb. The fatty acid derivative, palmitylcarnitine, failed to inhibitpyruvate oxidation at the level of decarboxylation. This finding supports the proposal that fatty acids do not inhibit glucose oxidation directly, but instead suppress glycogen breakdown. Thus, the findings indicate an increase in the capacity for- pyruvate oxidation during the rapid growth period without inhibition by the fatty acid derivative, palmitylc_arnitine. / Department of Biology

It has been widely recognized that aging will cause a profound decrease in glucose tolerance end increase insulin resistance. These changes have been found to occur at a relatively early age. Narimiya [54], has documented these changes in younger rots end has shown alterations in glycogen metabolism to occur prior to nine months of age. Exercise in the form of running has been shown to attenuate these changes. In Vivo, glucose, insulin end muscle glycogen have interrelated functions. The role of muscle glycogen is to provide energy for the muscle's contractile process. Insulin is needed at rest to allow glucose to enter the muscle and be stored as glycogen. The purpose of this study is to pinpoint when changes in glycogen metabolism occur while looking at the influence of exercise end weight restriction on the process. METHODS: Male Sprague Dawley rats ages 1.5-4.0 months of age were divided into three groups control (CN), pairfed (PF), and exercise trained (ET). The ET cages were equipped with voluntary running wheels attached to an automatic revolution counter. At 1.5 months, a group of controls were sacrificed and treated as the 4 mo. animals described below. Following training the hindlimbs of CN, ET, end PF were surgically isolated and glucose uptake examined by perfusing them with a bovine blood preparation, which contained insulin and glucose. Pre and post samples of the soleus, plantaris, and red and white vastus were removed and assayed for glycogen. RESULTS: The 1.5 mo. CN had significantly greater glucose uptake then any other group for both the insulin and non-insulin infused groups. The ET had significantly greater uptake than the other 4 mo. groups at 90 and 120 min in the insulin infused group. In the 1.5 mo. CN when insulin is not present all muscles will break down glycogen. When insulin is present, glycogen is used in all but the white vastus. In the 4 mo. CN all muscles except the soleus break down glycogen. In the ET the glycogen breakdown pattern is similar regardless of whether insulin is present or not. In the PF, glycogen breakdown is depressed and decidely different from the other treatment groups. CONCLUSIONS: There is an age dependent decrease in glucose tolerance and insulin resistance at or before 4 mo. of age. Training prevented some of this loss but did not stop the decline. Weight restriction had a nominal, if any, benefit in reducing insulin resistance and raising glucose tolerance with aging.

This study investigated the effects of an intervention designed to reduce the wandering of an 80 year old female resident of a long term care facility. A behavioral analysis of natural contingencies which maintained behaviors incompatible with wandering was conducted and the data from this analysis used to develop an intervention. The intervention simulated a dining room table and coffee break which naturally maintained sitting. An ABAC design revealed that this intervention was functionally related to a reduction in the proportion of a twenty minute interval spent wandering. The discussion focuses on possible causes of wandering and future directions for establishing a behavioral technology to control wandering.

According to the Socioemotional Selectivity Theory (SST), the normal aging process is associated with a greater emphasis on self-regulation of emotional states, and this fosters a bias in cognitive processing for information that is positively valenced (e.g., pleasant images and autobiographical events, happy faces), such that older adults have better memory for, and pay greater attention to, positive relative to negative valenced information (a ???positivity effect???). Two hypotheses have recently emerged which differ in the cognitive mechanism proposed to account for the emergence of aging-related positivity effects. The first, termed the ???cognitive control??? hypothesis, suggests that positivity effects arise from older adults' directed application of cognitive efforts to preferentially process positive information, essentially a top-down explanation. The second is a bottom-up hypothesis, suggesting that positive information is relatively easier (more fluent) for older adults to detect and process, compared to negative information, due to changes in amygdala reactivity to negative stimuli, and is termed the "processing fluency" hypothesis. To evaluate these hypotheses, I conducted a suite of memory and attention experiments and compared performance of younger and older adults. I used five different tasks (three different memory tasks, and two different attention tasks) which varied with respect to the degree to which each allowed for the use of cognitive control, and was reflective in nature, or emphasized fluency (i.e., speed of processing and output). In Experiments 1 and 2, I examined the effect of age on two different types of memory task that differed with respect to the degree to which participants must rely on cognitive control/reflective processing or processing fluency to successfully complete the task. Clear positivity effects were found on the task that was reflective in nature (autobiographical memory task) but not on the task that relied more heavily on fluency (phonemic fluency task). In Experiment 3, I examined whether older adults strategically select positive information to later remember (i.e., use cognitive control to regulate encoding of positive material), by asking participants to judge the likelihood of remembering positive, negative, and neutral pictures for a later memory test. In line with a strategic bias, older, but not younger, adults showed a positivity effect in terms of the number of pictures selected as particularly memorable, though both age groups showed a positivity effect in picture recall. Within the domain of attention-based tasks, in Experiments 4a and 4b I used a Rapid Serial Visual Presentation (RSVP) paradigm to examine whether older adults were more likely to detect (or have attention captured by) rapidly presented positive, than negative or neutral, pictures compared to younger adults. Given the rapid rate of presentation in this paradigm, it is unlikely that participants would be able to use cognitive control to strategically direct attention to positive stimuli, thus performance was taken to measure fluency-mediated biases for the pictures of different valence. Results showed little evidence for a positivity effect. In Experiments 5a and 5b, again within the domain of attention, I examined whether older adults preferentially oriented attention toward positive, and/or away from negative, relative to neutral stimuli, on a dot probe task in which trial timings were long enough to allow for strategic control. Experiment 5a used faces whereas Experiment 5b used pictures as stimuli, in an effort to determine whether findings could generalize across different types of stimuli. Some evidence of positivity effects were found, as older adults were less biased to attend to negative (angry) faces compared to younger adults. Results across this series of experiments are consistent with the hypothesis that positivity effects in older adults' memory and attention stem from the strategic application of effortful, reflective, cognitive processing, rather than a bottom-up difference in processing fluency.

The purpose of this study was to examine whether perceived neighbourhood characteristics and personal characteristics in 2007/2008 predicted health-related outcomes: steps taken per day, life-space mobility, physical function, body mass index (BMI), and body composition-related health benefits in 2010/2011 among community-dwelling older adults. The total sample consisted of 341 men and women above the age of 62 years. Steps per day were measured using pedometers for a 3-day period and the change score was reported as a binary outcome: increased steps and decreased steps. Life-space mobility was assessed using the Life-Space Assessment and the outcome was the life-space score as a continuous variable. Physical function was assessed using the Late Life Function and Disability Instrument. The outcome was the total score as a continuous variable. BMI was assessed using the index of the participants’ self-reported weight divided by the height squared. Body composition-related health benefits were assessed using the participants’ BMI refined by the participants’ self-assessed waist circumference. The independent variable was the perception of the neighbourhood environment assessed using select items of the Neighbourhood Environment Walkability Scale in four categories: presence and maintenance of sidewalks; aesthetics; walkability safety; and traffic safety. Demographic and health information (sex, age, self-rated health, physical function limitations, number of chronic conditions and body mass index) were also collected. Regression analysis showed that although more positive perceptions of neighbourhood characteristics such as walkability safety, traffic safety and sidewalks were associated with health-related outcomes, overall, the perceived neighbourhood environment was not a strong predictor of health-related outcomes among community-dwelling older adults. These outcomes were mostly predicted by demographic and health status variables (i.e. chronic conditions, self-rated health, body mass index, physical function limitations). Initiatives targeted at the neighbourhood environment should consider the health-related outcome of interest (i.e. walking, mobility, physical function or obesity), the specific age group (i.e. old age or very old age and oldest old age), and the importance of demographic and health variables in shaping the relationship between the neighbourhood environment and these outcomes.

This thesis investigates the differential effects of muscle fatigue on center of pressure (COP) sway and associated central processes (attentional demands and sensory re-weighting) in older compared with young adults. More specifically, we first sought to determine whether the effect of muscle fatigue on unipedal stance was greater during a dual-task in older versus young adults, and second, to determine whether the effect of muscle fatigue on bipedal stance was greater in a condition with less reliable proprioceptive information in older versus young adults. Our main results show that with different muscle groups fatigued (ankle or hip) and postural tasks with varying difficulty (unipedal stance or bipedal stance on compliant surface), young adults increased their COP sway displacement and velocity with muscle fatigue, but not the associated attentional demands. When the central nervous system needed to increase the weight of the vestibular inputs due to sensory information being less reliable at the ankle joints from standing on a compliant surface (peripheral somatosensory information), COP sway displacement and velocity in young adults were greater with ankle muscle fatigue. We also found that healthy older adults were able to compensate for muscle fatigue just as well as young adults when visual information was available during a unipedal stance or when visual information was not available during a bipedal stance on a firm surface. However, when standing on a compliant surface, older adults showed a greater increase in COP sway displacement compared to young adults and increased attentional demands when visual information was not available during a bipedal stance. Our results suggest that healthy young and older adults are able to compensate for ankle muscle fatigue to limit postural control alterations during quiet standing under different conditions, and that the extent of postural control alterations largely depends on the tasks performed. The compensation strategies may be less efficient for older adults with less reliable proprioceptive information and without vision. Thus, a frailer group of older adults, with already reduced proprioception and/or reduced vision could possibly have more difficulty to efficiently use the same compensation strategies, and may be more at risk of falling when fatigued.

Recent neuropsychological research has stressed the sensitivity of the Prefrontal Cortex, mostly the Dorsolateral region, in relation to aging (Darowski et al., 2008). Prefrontal Cortex functions, such as Inhibitory Control (IC), are thought to wane steadily after the ages of 60-65 (Craik & Bialystok, 2006). Little is known about what changes occur between the stages of prefrontal optimal performance (i.e., ages 20-25), and the later periods of functional decline. The present study aimed to investigate performance differences between younger (ages 30-40; n=9), middle-aged (ages 50-60; n=10), and older adults (ages 70 and up; n=13), on five tasks of Executive Functions (EFs); specifically, assessing the abilities of problem representation, shifting, updating working memory, inhibition, and integrating valence and rewards into pursuing a goal. It was hypothesized that (a) quantitative age trends differentiating the three groups on the tasks would be found, (b) IC would be particularly targeted by the hypothesized age trends, and (c) the devolution of IC across the adult lifespan would be linear. MANOVA tests with all tasks of EFs representing the Dependent Variables and age serving as the Independent Variable revealed no significant main effect. Follow-up separate ANOVA tests however, suggested a statistically significant difference between the means of Groups 2 and 3 for the Updating Working Memory task, F(2,29)=5.374, p=.010, Scheffe (p=.012) and Bonferroni (p=.010). The contributions of interactions among EFs to the present results, recruitment challenges, and potential age effects are discussed. / Graduate / 0622 / emiliecq@uvic.ca