When is a proxy not a proxy? The foibles of studying non‐image forming light

The Journal of Physiology, EarlyView.


from Physiology via xlomafota13 on Inoreader https://ift.tt/2rflVqI
via IFTTT

Functional decoupling of melatonin suppression and circadian phase resetting in humans

The Journal of Physiology, EarlyView.


from Physiology via xlomafota13 on Inoreader https://ift.tt/2KugX1S
via IFTTT

Issue Information

The Journal of Physiology, Volume 596, Issue 9, Page 1529-1530, 1 May 2018.


from Physiology via xlomafota13 on Inoreader https://ift.tt/2KxjnwP
via IFTTT

Altered autonomic control of heart rate variability in the chronically hypoxic fetus

The Journal of Physiology, EarlyView.


from Physiology via xlomafota13 on Inoreader https://ift.tt/2rgvntR
via IFTTT

Electromagnetic field exposure (50 Hz) impairs response to noxious heat in American cockroach

Abstract

Exposure to electromagnetic field (EMF) induces physiological changes in organism that are observed at different levels—from biochemical processes to behavior. In this study, we evaluated the effect of EMF exposure (50 Hz, 7 mT) on cockroach's response to noxious heat, measured as the latency to escape from high ambient temperature. We also measured the levels of lipid peroxidation and glutathione content as markers of oxidative balance in cockroaches exposed to EMF. Our results showed that exposure to EMF for 24, 72 h and 7 days significantly increases the latency to escape from noxious heat. Malondialdehyde (MDA) levels increased significantly after 24-h EMF exposure and remained elevated up to 7 days of exposure. Glutathione levels significantly declined in cockroaches exposed to EMF for 7 days. These results demonstrate that EMF exposure is a considerable stress factor that affects oxidative state and heat perception in American cockroach.

from Physiology via xlomafota13 on Inoreader https://ift.tt/2jpIipZ
via IFTTT

Association of Lower Limb Compression Garments During High-Intensity Exercise with Performance and Physiological Responses: A Systematic Review and Meta-analysis

Abstract

Background

Although compression garments are used to improve sports performance, methodological approaches and the direction of evidence regarding garments for use in high-intensity exercise settings are diverse.

Objectives

Our primary aim was to summarize the association between lower-limb compression garments (LLCGs) and changes in sports performance during high-intensity exercise. We also aimed to summarize evidence about the following physiological parameters related to sports performance: vertical jump height (VJ), maximal oxygen uptake (VO₂max), submaximal oxygen uptake (VO₂submax), blood lactate concentrations ([La]), and ratings of perceived exertion (RPE, 6–20 Borg scale).

Methods

We searched electronic databases (PubMed, EMBASE, Cochrane Library, and ClinicalTrials.gov) and reference lists for previous reviews. Eligible studies included randomized controlled trials with athletes or physically active subjects (≥ 18 years) using any type of LLCG during high-intensity exercise. The results were described as weighted mean difference (WMD) with a 95% confidence interval (95% CI).

Results

The 23 included studies showed low statistical heterogeneity for the pooled outcomes. We found that LLCGs yielded similar running performance to controls (50–400 m: WMD 0.06 s [95% CI − 1.99 to 2.11]; 800–3000 m: WMD 6.10 s [95% CI − 7.23 to 19.43]; > 5000 m: WMD 1.01 s [95% CI − 84.80 to 86.82]). Likewise, we found no evidence that LLCGs were superior in secondary outcomes (VJ: WMD 2.25 cm [95% CI − 2.51 to 7.02]; VO₂max: WMD 0.24 mL.kg⁻¹.min⁻¹ [95% CI − 1.48 to 1.95]; VO₂submax: WMD − 0.26 mL.kg⁻¹.min⁻¹ [95% CI − 2.66 to 2.14]; [La]: WMD 0.19 mmol/L [95% CI − 0.22 to 0.60]; RPE: WMD − 0.20 points [95% CI − 0.48 to 0.08]).

Conclusions

LLCGs were not associated with improved performance in VJ, VO₂max, VO₂submax, [La], or RPE during high-intensity exercise. Such evidence should be taken into account when considering using LLCGs to enhance running performance.

from Sports Medicine via xlomafota13 on Inoreader https://ift.tt/2rdWc1C
via IFTTT

Relationships Between Neighbourhood Physical Environmental Attributes and Older Adults’ Leisure-Time Physical Activity: A Systematic Review and Meta-Analysis

Abstract

Background

Activity-friendly neighbourhood physical environments with access to recreational facilities are hypothesised to facilitate leisure-time physical activity (LTPA) among older adults (≥ 65 years old). The aim of the current study was to systematically review and quantitatively summarise study findings on the relationships between physical environmental attributes and LTPA among older adults.

Methods

An extensive search of literature, including grey literature, yielded 72 articles eligible for inclusion. The reported associations between seven categories of environmental attributes and six LTPA outcomes were extracted, weighted by sample size and study quality, and quantitatively summarised. Reported moderating effects of individual and environmental characteristics and neighbourhood definition were also examined.

Results

We observed positive associations for walkability (p = 0.01), land-use mix—access (p = 0.02) and aesthetically pleasing scenery (p < 0.001) with leisure-time walking. For leisure-time walking within the neighbourhood, evidence was found for positive associations with land-use mix—access (p = 0.03) and access to public transit (p = 0.05), and a negative association with barriers to walking/cycling (p = 0.03). Evidence for positive relationships between overall LTPA and access to recreational facilities (p = 0.01) and parks/open space (p = 0.04) was found. Several environmental attribute–LTPA outcome combinations were insufficiently studied to draw conclusions. No consistent moderating effects were observed for individual and environmental characteristics and neighbourhood definition.

Conclusions

The observed significant relationships can be used to inform policy makers and planners on how to (re-)design neighbourhoods that promote LTPA among older adults. Many environmental attribute–LTPA outcome relationships have been studied insufficiently and several methodological issues remain to be addressed.

Systematic Review Registration Number

PROSPERO 2016:CRD42016051180.

from Sports Medicine via xlomafota13 on Inoreader https://ift.tt/2KxZhCu
via IFTTT