This investigation assessed the effects of acute aerobic exercise (AE) on cardiovascular reactivity (CVR) to a non-exercise stressor. Nineteen untrained, healthy male volunteers were stratified on diastolic blood pressure (DBP) response to the cold pressor test (CPT), then randomly assigned to either a minimal exercise condition (5 min of freewheel cycling) or 30 min of exercise on a bicycle ergometer at 55-60% V02max. Heart rate (HR) and BP were monitored during the resting, arousal, and recovery phases of the CPT at 1 hr, 3 hr, and 24 hr post-exercise. Results revealed statistically non-significant response and recovery effects; however, two important trends emerged. The 30 minute exercise group exhibited a tendency toward a reduced DBP response to the CPT during the 1 hour post-exercise session (p=0.08) and SBP response to the CPT was lower in the 30 minute exercise group at 3 hours post-exercise (p=0.08). These findings provide only minimal support for the effectiveness of 30 minutes of AE at 55-60% V02max in attenuating physiological response to the CPT in untrained males. / Master of Science

This research investigates the question of how people undertake health behavior change. It attempts to define what people experience and do during the process of changing health related aspects of their lives. The question of how people make health relevant changes in, their habits and actions has become increasingly important as the responsibility for one's health has shifted from the medical care system to the individual... / Ph. D.

This study describes the effects of a structured employee wellness program as related to stress management in an elementary school of thirty-eight staff members. The study was designed to measure the residual effects of the intervention program after subjects completed the sustained personal program of stress management with emphasis on relaxation techniques. The research design in which the wellness program tested was a behavioral modification study which used subjects as their own controls across two baseline stress assessments. The instruments used to measure the perceived sources of stress, levels of stress, subjects knowledge of stress, and identified symptoms of stress were: 1)the General Well·Being Schedule; 2)How to Manage Stress Computer Program Tests; 3)State-Trait Anxiety Inventory and 4) Personal Exit Interviews. These assessment instruments, except for the interviews, were used before and after each intervention treatment. In addition to the above measures, other criterion data included observations during the intervention program and after individual and group activities. These observations were done to show how school employees succeed in using stress management and relaxation techniques after exposure to the specific interventions. Analysis was made using network comparisons across both assessment periods. The networking included the implementation of Stress Managing Techniques and How to Manage Stress Computer Program. / Ed. D.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Orientador: Danísio Prado Munari / Coorientador: Clara Díaz Martín / Banca: Rodrigo Pelicioni Savegnago / Banca: Larissa Fernanda Simielli Fonseca / Banca: Tatiane Cristina Seleguim Chud / Banca: Daniel Guariz Pinheiro / Resumo: Na produção de carne bovina, os animais são expostos a condições de abate que induzem diferentes respostas ao estresse e essas diferenças podem ser genéticas. Os objetivos deste estudo foram: (1) caracterizar o padrão de resposta de genes de proteínas de choque térmico (HSP) entre Psoas major (PM) e Flexor digitorum superficialis (FD) em resposta ao estresse ao abate em duas estações diferentes (verão e inverno). Isso foi feito para determinar se a resposta das HSPs ao estresse ao abate estava condicionada ao tipo muscular e ao estresse térmico; (2) (a) caracterizar a resposta fisiológica ao estresse gerado pelo manejo dos animais em dois períodos distintos no tempo, manejo em confinamento (F) e manejo ao abate (S) com um conjunto de biomarcadores; (b) identificar um subgrupo dos biomarcadores de estresse que melhor discriminam entre os dois períodos e avaliar se a resposta inicial em F poderia ser usada para antecipar a resposta em S, e (c) encontrar evidências de um componente genético na resposta fisiológica ao estresse em bovinos de corte. Estimativas das diferenças de expressão entre FD e PM para oito genes de proteínas de choque térmico foram usadas neste estudo. Os resultados mostraram que ambos os músculos parecem ter padrões semelhantes na expressão de HSPs sob estímulos térmicos, exceto HSPB6 e HSPB8, que mostraram maior nível de expressão no músculo PM de animais abatidos no verão em relação aos mesmos abatidos no inverno. A suscetibilidade e, portanto, a resposta ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In beef production, animals are exposed to slaughter conditions that induce different responses to stress and these differences may be are genetics. Therefore, this study aimed: (1) to characterize the pattern of response of heat shock protein genes (HSP) between Psoas major (PM) and Flexor digitorum superficialis (FD) in response to stress at slaughter in two different seasons (summary and winter). This was so to determine if response of HSP to the stress of slaughter was conditioned on muscle type and thermal stress; (2) (a) to characterize the physiological response to stress generating by handling the animals at two different periods in time, feedlot (F) and slaughter (S) with a set of biomarkers; (b) to identify a subset of the biomarkers of stress that best discriminate between these two stress periods and to evaluate if the early response in F could be used to anticipate response at S, and (c) find evidences of a genetic component in the physiological response to stress in beef cattle. Estimate expression differences between FD and PM for eight heat shock protein genes were used in HSPs study. Results showed that both muscles seem to have similar patterns in the expression of HSPs at the thermal stimuli except the HSPB6 and HSPB8 that seemed to show a larger level of expression in PM muscles of animals slaughtered at summer than those that were sampled in the winter slaughter. The susceptibility and, therefore, the response to thermal stress seems to be differentially ... (Complete abstract click electronic access below) / Doutor

A dissertation submitted in fulfilment of the requirements for the degree Master of Science in Engineering, in the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg. January 2017 Johannesburg / It is well known that emotional stress has a negative impact on people’s health and physical, emotional and mental performance. Previous research has investigated the effects of stress on various aspects of physiology such as respiration, heart rate, heart rate variability (HRV), skin conductance, skin temperature and electrical activity in the brain. Essentially, HRV, Electroencephalography (EEG), skin conductance and skin temperature appear to reflect a stress response or state of arousal. Whilst the relationship between respiration rate, respiration rhythm and HRV is well documented, less is known about the relationship between respiration rate, EEG, skin conductance and skin temperature, whilst HRV is maximum (when there is resonance between HRV and respiration i.e. in phase with one another). This research project aims to investigate the impact that one session of slow paced breathing has on EEG, heart rate variability (HRV), skin conductance and skin temperature. Twenty male participants were randomly assigned to either a control or intervention group. Physiological data were recorded for the intervention and control group during one breathing session, over a short initial baseline (B1), a main session of 12 minutes, and a final baseline (B2). The only difference between the control and intervention groups was that during the main session, the intervention group practiced slow paced breathing (at 6 breaths per minute), while the control group breathed spontaneously. Wavelet transformation was used to analyse EEG data while Fourier transformation was used to analyse HRV. The study shows that slow-paced breathing significantly increases the low frequency and total power of the HRV but does not change the high frequency power of HRV. Furthermore, skin temperature significantly increased for the control group from B1 to Main, and was significantly higher for the control group when compared to the intervention group during the main session. There were no significant skin temperature changes between sessions for the intervention group. Skin conductance increased significantly from Main to B2 for the control group. No significant changes were found between sessions for the intervention group and between groups. EEG theta power at Cz decreased significantly from Main to B2 for the control group only, while theta power decreased at F4 from Main to B2 for both groups. Lastly, beta power at Cz decreased from B1 to B2 for the control group only. This significant effect that slow-paced breathing has on HRV suggests the hypothesis that with frequent practice, basal HRV would increase, and with it, potential benefits such as a reduction in anxiety and improved performance in specific tasks. Slow-paced breathing biofeedback thus shows promise as a simple, cheap, measurable and effective method to reduce the impact of stress on some physiological signals, suggesting a direction for future research. / MT2017

A research report submitted to the Department of Social Work, School of Human and Community Development, Faculty of Humanities, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Master of Arts in Occupational Social Work, 2016 / The primary purpose of this study was to explore the experiences of occupational stress among social workers employed by the Department of Social Development in Mpumalanga Province, Ehlanzeni District. Mpumalanga Province is predominantly rural and the assumption is that work-related challenges for social workers in rural areas are different from urban areas. There are theoretical basis suggesting that people view and respond to stress differently thus their coping strategies even in identical situations are different. The study has therefore focused on the experiences of occupational stress among social workers, the contributory factors that led to occupational stress, the impact of occupational stress, the social workers’ coping strategies with occupational stress; and the availability and effectiveness of organisational support offered to employees experiencing occupational stress as perceived by social workers. The research used both qualitative and quantitative methods. The researcher utilised a questionnaire consisting of open-ended questions, together with the Work-Related Quality of Life scale consisting of closed questions that measured work stress, administered to 40 social workers employed at Ehlanzeni District offices. One year’s working experience as a social worker in the Department of Social Development was a qualifying criterion in the study. Thematic content analysis and descriptive statistical analysis were used to analyse data. The findings of the study suggested that unsatisfactory salaries, working conditions, high workload, lack of recognition and a lack of support were the main stressors for social workers in this study. The research concluded with recommendations that will hopefully assist in improving the quality of work-life of the sound workers and facilitate a balanced understanding between the employees and the employer. / GR2017

Rhodopseudomonas palustris is a metabolically versatile phototrophic α-proteobacterium. The organism experiences a wide range of stresses in its environment and during metabolism. The oxidative an pH stresses of four ECF (extracytoplasmic function) σ-factors are investigated. Three of these, σ0550, σ1813, and σ1819 show responses to light-generated singlet oxygen and respiration-generated superoxide reactive oxygen species (ROS). The EcfG homolog, σ4225, shows a high response to superoxide and acid stress. Two proteins, one containing the EcfG regulatory sequence, and an alternative exported catalase, KatE, are presented to be regulated by σ4225. Transcripts of both genes show similar responses to oxidative stress compared to σ4225, indicating it is the EcfG-like σ-factor homolog and controls the global stress response in R. palustris.

Poor semen quality is an indicator of male infertility and is also associated with a variety of adverse health outcomes in men. It is therefore important from both clinical and public health perspectives to discover predictors of poor semen quality, especially those that are potentially modifiable. My dissertation research focuses on two of these potential risk factors: adiposity and stress. Unlike most studies to date, which have only considered the relationship between these exposures and semen quality cross-sectionally, my research takes a life course approach. I explore associations between birth weight, adiposity in both childhood and adulthood, and allostatic load—a construct representing the effect of cumulative stress on the body’s regulatory systems—and three commonly-used semen outcome parameters: sperm concentration, percent progressive motility, and percent normal morphology. The logic that underlies this approach is that while sperm are constantly being produced from sperm stem cells in the testes, which would argue in favor of cross-sectional studies, the sperm stem cells themselves and the Sertoli and Leydig cells that stimulate and nurture that metamorphosis are laid down in the fetal period and undergo important developmental and proliferative phases during early childhood and puberty that affect their number and functional health in adulthood. Using data from 193 participants in the Study of the Environment and Reproductive health follow-up to the Child Health and Development Studies birth cohort, I was able to calculate birth weight for gestational age percentile (bw/ga) and six age-appropriate adiposity measures (at 4 months, 12 months, and 4 years, and in participants’ 20s, 30s, and at the time of semen collection), then test for their independent, critical period, and cumulative associations with the three semen outcomes as well as a combined outcome measure of subfertility based on World Health Organization reference levels. While bw/ga was positively associated with sperm concentration, subsequent childhood adiposity measures showed increasingly negative associations, and none of the adult measures were significantly associated with concentration. By contrast, only adult measures were associated with motility and morphology. This suggests that there may be critical periods in childhood when adiposity negatively affects sperm concentration by interfering with the development and proliferation of Sertoli and Leydig cells. Accumulation of oxidative stress in the testes due to overweight/obesity may explain the negative relationships between adult adiposity and sperm motility and morphology. To investigate allostatic load’s relationship to semen quality, I conducted a pilot study at Columbia University’s Center for Women’s Reproductive Care that enrolled 61 men who were having their initial diagnostic semen analysis and blood draw on the same day. Blood samples were analyzed for 7 biomarkers associated with homeostatic regulation across several physiologic domains. I then created an allostatic load scale in which participants were assigned 1 point for being in the high-risk quartile for systolic blood pressure, diastolic blood pressure, body mass index, or any of the biomarkers. In regression analyses, allostatic load was not associated with either sperm concentration or morphology, but showed an unexpected positive association with motility. This association was entirely driven by the six participants who scored 0 on the allostatic load scale and who did not differ from the rest of the sample in any way that could plausibly be linked to reduced motility. I therefore concluded that this was a spurious finding. In further analysis of the allostatic load variable itself, I found that few of its individual components were correlated with the semen outcomes. This contrasts with other studies of allostatic load and adverse health outcomes, but these have generally been conducted in either elderly or stressed populations, neither of which described my cohort. Allostatic load may not be a reliable measure of stress in reproductive age populations and may not capture regulatory systems appropriate to reproductive health outcomes. My dissertation highlights the value and challenges of conducting semen quality research from a life course perspective. Future studies should consider collecting longitudinal data on adiposity and stress, as well as repeated semen samples beginning in adolescence in order to further our understanding of the natural progression of semen quality across the reproductive life span and provide the opportunity to explore whether modifying these risk factors affects semen quality.

Includes bibliographical references (leaves 183-207) A local intradermal technique using colchicine to estimate cell division rate in wool follicles is refined and used throughout the thesis. Statistical methods used to analyse data obtained with this method are described and discussed. The implications of the findings are of great significance to research into the influence of physiological changes on wool production, and suggest experiments should be conducted under controlled environmental conditions, with a minimum of stress imposed on the animals.