489 research outputs found
Associations of Health Club Membership with Physical Activity and Cardiovascular Health
Introduction This study evaluates whether a health club membership is associated with meeting the US physical activity (PA) guidelines and/or favorable cardiovascular health.
Methods Using cross-sectional data of health club members (n = 204) and non-members (n = 201) from April to August 2013, this is the first study to our knowledge to examine a health club membership in relation to objectively measured cardiovascular health indicators including resting blood pressure, resting heart rate, body mass index, waist circumference, and cardio respiratory fitness based on a non-exercise test algorithm. To determine the total PA and sedentary time, this study used a comprehensive PA questionnaire about both aerobic and resistance activities at the health club, as well as lifestyle activities in other settings, which was developed based on the International Physical Activity Questionnaire (IPAQ).
Results The odds ratios (95% confidence interval) of meeting either the aerobic, resistance, or both aerobic and resistance PA guidelines for members compared to non-members were 16.5 (9.8–27.6), 10.1 (6.2–16.3), and 13.8 (8.5–22.4), respectively. Significant associations of health club membership with more favorable cardiovascular health outcomes and sedentary behavior were observed for resting heart rate (B: -4.8 b/min, p\u3c0.001), cardiorespiratory fitness (B: 2.1 ml/kg/min, p\u3c0.001), and sedentary time (B: -1.4 hours, p\u3c0.001). Participants with a health club membership of \u3e1 year had more favorable health outcomes, with a smaller waist circumference (men, B: -4.0 cm, p = 0.04; women, B: -3.4 cm, p = 0.06), compared to non-members.
Conclusions Health club membership is associated with significantly increased aerobic and resistance physical activity levels and more favorable cardiovascular health outcomes compared to non-members. However, longitudinal, randomized controlled trials would be clearly warranted as cross-sectional data prohibits causal inferences
Graduated Stress Exposure of Spaceflight Hazards in a Virtual Environment
Stress experienced by astronauts during high-level hazardous situations may poses risk to personnel wellbeing and to mission success. Stress inoculation training (SIT) provides individuals with experience of minor stressors and coping skills during non-critical times to enhance their resistance to stress. This study evaluates the effect of exposure to a low level stressor on physiological response and cognitive load in high level stressor setting. Simulation of fire emergency on the International Space Station (ISS) in a full-scale, immersive, interactive, 3D virtual reality environment facilitated a process for stress inoculation. The experimental settings included two groups that have been exposed to either virtual no-smoke or to virtual light-smoke conditions. The two groups then experienced a subsequent stress exposure in a later trail to heavy-smoke conditions. Physiological responses and cognitive load measure were collected during the trials. The results indicated weak differences in physiological responses between the two groups, in the heavy smoke conditions. Overall, no significant differences have been detected on cognitive load categories according to NASA TLX
Relationships Among Stress Measures, Risk Factors, and Inflammatory Biomarkers in Law Enforcement Officers
Law enforcement officers suffer higher morbidity and mortality rates from all causes than the general population. Cardiovascular disease (CVD) accounts for a significant portion of the excess illness, with a reported prevalence as high as 1.7 times that of the general population. To determine which occupational hazards cause this increased risk and morbidity, it is imperative to study law enforcement officers before they retire. The long-range goal of our research is to reduce the incidence of CVD-related illness and death among aging law enforcement officers. The purpose of the present study was to measure pro- and anti-atherogenic inflammatory markers in blood samples from law enforcement officers (n = 71) and determine what types of occupation-related stress correlate with differences in these markers. For each outcome variable of interest, we developed separate regression models. Two groups of potential predictors were examined for inclusion in the models. Selected measures of stress were examined for inclusion in the models, in addition to general covariates, such as gender, ethnicity, years in law enforcement, and body mass index. Our results revealed statistically significant relationships between several physiologic variables and measures of stress
Intergenerational Service Learning Program Improves Aging Knowledge and Expectations and Reduces Ageism in Younger Adults
This article discusses a study which evaluated the effects of an intergenerational service-learning exergaming program for older adults on younger adults’ aging knowledge, expectations, and perceptions. Eighteen college students (ages 19-26 years) served as trainers for an 8-week exergaming physical activity program for older adults (12 contact hours). Questionnaires assessing aging knowledge, ageist attitudes and aging expectations were completed at Weeks 1, 8, and 25 (follow-up); program evaluations were completed at Weeks 8 and 25. Significant improvement from Week 1 to Week 25 was found for: Aging knowledge scores (
Hyperpolarization-Activated Current (Ih) in Ganglion-Cell Photoreceptors
Intrinsically photosensitive retinal ganglion cells (ipRGCs) express the photopigment melanopsin and serve as the primary retinal drivers of non-image-forming visual functions such as circadian photoentrainment, the pupillary light reflex, and suppression of melatonin production in the pineal. Past electrophysiological studies of these cells have focused on their intrinsic photosensitivity and synaptic inputs. Much less is known about their voltage-gated channels and how these might shape their output to non-image-forming visual centers. Here, we show that rat ipRGCs retrolabeled from the suprachiasmatic nucleus (SCN) express a hyperpolarization-activated inwardly-rectifying current (Ih). This current is blocked by the known Ih blockers ZD7288 and extracellular cesium. As in other systems, including other retinal ganglion cells, Ih in ipRGCs is characterized by slow kinetics and a slightly greater permeability for K+ than for Na+. Unlike in other systems, however, Ih in ipRGCs apparently does not actively contribute to resting membrane potential. We also explore non-specific effects of the common Ih blocker ZD7288 on rebound depolarization and evoked spiking and discuss possible functional roles of Ih in non-image-forming vision. This study is the first to characterize Ih in a well-defined population of retinal ganglion cells, namely SCN-projecting ipRGCs
Transfer origins in the conjugative Enterococcus faecalis plasmids pAD1 and pAM373: identification of the pAD1 nic site, a specific relaxase and a possible TraG-like protein
The Enterococcus faecalis conjugative plasmids pAD1 and pAM373 encode a mating response to the peptide sex pheromones cAD1 and cAM373 respectively. Sequence determination of both plasmids has recently been completed with strong similarity evident over many of the structural genes related to conjugation. pAD1 has two origins of transfer, with oriT1 being located within the repA determinant, whereas the more efficiently utilized oriT2 is located between orf53 and orf57 , two genes found in the present study to be essential for conjugation. We have found a similarly located oriT to be present in pAM373. oriT2 corresponds to about 285 bp based on its ability to facilitate mobilization by pAD1 when ligated to the shuttle vector pAM401; however, it was not mobilized by pAM373. In contrast, a similarly ligated fragment containing the oriT of pAM373 did not facilitate mobilization by pAD1 but was efficiently mobilized by pAM373. The oriT sites of the two plasmids each contained a homologous large inverted repeat (spanning about 140 bp) adjacent to a series of non-homologous short (6 bp) direct repeats. A hybrid construction containing the inverted repeat of pAM373 and direct repeats of pAD1 was mobilized efficiently by pAD1 but not by pAM373, indicating a significantly greater degree of specificity is associated with the direct repeats. Mutational (deletion) analyses of the pAD1 oriT2 inverted repeat structure suggested its importance in facilitating transfer or perhaps ligation of the ends of the newly transferred DNA strand. Analyses showed that Orf57 (to be called TraX) is the relaxase, which was found to induce a specific nick in the large inverted repeat inside oriT ; the protein also facilitated site-specific recombination between two oriT2 sites. Orf53 (to be called TraW) exhibits certain structural similarities to TraG-like proteins, although there is little overall homology.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72536/1/j.1365-2958.2002.03007.x.pd
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