12 research outputs found
The effect of a 2-week ischaemic preconditioning intervention on anaerobic performance in male academy football players: a randomized, single-blinded, SHAM-Controlled study
Ischaemic preconditioning (IPC), brief periods of ischaemia immediately followed by reperfusion applied to a vascular bed, has emerged as a method to improve exercise performance. There is, however, a lack of research exploring repeated episodes of IPC on anaerobic performance. The aim of this study was to determine if a 2-week repeated IPC intervention could enhance anaerobic performance in male academy football players. Eight male academy football players completed two, 2-week intervention trials: six IPC episodes (4 × 5 min at 220 mmHg per episode), and six SHAM episodes (4 × 5 min at 20 mmHg per episode). Prior to and following each intervention trial, the participants completed assessments of anaerobic performance (Running Anaerobic Sprint Test [RAST]), and superficial femoral artery endothelial function (flow-mediated dilation [FMD]). IPC significantly enhanced peak and mean power output by 12% (p = 0.026) and 11% (p = 0.019) and significantly improved superficial femoral artery FMD (p = 0.049). The increase in endothelial function suggests that this may be a mechanism contributing to this enhancement of anaerobic performance. The present study supports the use of repeated IPC prior to matches and training sessions to enhance anaerobic performance
The James Webb Space Telescope Mission
Twenty-six years ago a small committee report, building on earlier studies,
expounded a compelling and poetic vision for the future of astronomy, calling
for an infrared-optimized space telescope with an aperture of at least .
With the support of their governments in the US, Europe, and Canada, 20,000
people realized that vision as the James Webb Space Telescope. A
generation of astronomers will celebrate their accomplishments for the life of
the mission, potentially as long as 20 years, and beyond. This report and the
scientific discoveries that follow are extended thank-you notes to the 20,000
team members. The telescope is working perfectly, with much better image
quality than expected. In this and accompanying papers, we give a brief
history, describe the observatory, outline its objectives and current observing
program, and discuss the inventions and people who made it possible. We cite
detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space
Telescope Overview, 29 pages, 4 figure
Genomic Dissection of Bipolar Disorder and Schizophrenia, Including 28 Subphenotypes
publisher: Elsevier articletitle: Genomic Dissection of Bipolar Disorder and Schizophrenia, Including 28 Subphenotypes journaltitle: Cell articlelink: https://doi.org/10.1016/j.cell.2018.05.046 content_type: article copyright: © 2018 Elsevier Inc
The Effect of a 2-Week Ischemic Preconditioning Intervention on Anaerobic Performance in Non-Elite Male Soccer Players
Introduction: Ischemic preconditioning (IPC), brief periods of ischemia immediately followed by reperfusion applied to a vascular bed, has emerged as a method to improve athletic performance across various types of exercise (aerobic and anaerobic). Although there has been a great deal of literature investigating IPC on exercise performance, there is a lack of focus on the effect of repeated episodes of IPC along with measuring anaerobic performance via repeated sprint ability (RSA). IPC has been reported to improve blood flow and enhance endothelial function, which could be mechanisms to explain enhanced RSA performance. The aim of this thesis was to: 1) determine if a 2-week repeated IPC intervention could enhance anaerobic performance in RSA in non-elite soccer players; 2) assess whether improvements in endothelial function is a mechanism explaining any performance enhancement. Methods: Using a randomised, single-blinded crossover design, 8 non-elite male academy soccer players completed two, 2-week intervention trials: six IPC episodes (4 x 5 mins at 220mmHg per episode), and six SHAM episodes (4 x 5 mins at 20mmHg per episode). Prior to and following each intervention trial, participants completed
assessments of anaerobic performance (Running Anaerobic Sprint Test [RAST]), and femoral
artery endothelial function (flow-mediated dilation [FMD]). Results: IPC significantly enhanced peak power output (PPO) in the RAST by 11.30% (p=0.010) and significantly increased femoral artery FMD by 1.72% (p=0.018). Discussion: A 2-week repeated IPC intervention can improve anaerobic performance by means of increased PPO during repeated sprints. The increase in endothelial function following the repeated IPC intervention suggests this may be a mechanism contributing to this enhancement of anaerobic performance. Conclusion: The present study supports the use of repeated IPC prior to matches and training sessions in order to enhance anaerobic performance and encourages coaches to implement the cost-effective method into their teams’ daily schedule
Recommended from our members
Specimen collection is essential for modern science.
Natural history museums are vital repositories of specimens, samples and data that inform about the natural world; this Formal Comment revisits a Perspective that advocated for the adoption of compassionate collection practices, querying whether it will ever be possible to completely do away with whole animal specimen collection
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Probing Galaxy Evolution in Massive Clusters Using ACT and DES: Splashback as a Cosmic Clock
We measure the projected number density profiles of galaxies and the splashback feature in clusters selected by the Sunyaev–Zel’dovich effect from the Advanced Atacama Cosmology Telescope (AdvACT) survey using galaxies observed by the Dark Energy Survey (DES). The splashback radius is consistent with CDM-only simulations and is located at -
+ -h2.4 Mpc0.4 0.3 1. We split the galaxies on color and find significant differences in their profile shapes.
Red and green-valley galaxies show a splashback-like minimum in their slope profile consistent with theory, while the bluest galaxies show a weak feature at a smaller radius. We develop a mapping of galaxies to subhalos in simulations and assign colors based on infall time onto their hosts. We find that the shift in location of the steepest slope and different profile shapes can be mapped to the average time of infall of galaxies of different colors. The steepest slope traces a discontinuity in the phase space of dark matter halos. By relating spatial profiles to infall time, we can use splashback as a clock to understand galaxy quenching. We find that red galaxies have on average been in clusters over 3.2 Gyr, green galaxies about 2.2 Gyr, while blue galaxies have been accreted most recently and have not reached apocenter. Using the full radial profiles, we fit a simple quenching model and find that the onset of galaxy quenching occurs after a delay of about a gigayear and that galaxies quench rapidly thereafter with
an exponential timescale of 0.6 Gyr
Probing Galaxy Evolution in Massive Clusters Using ACT and DES: Splashback as a Cosmic Clock
International audienceWe measure the projected number density profiles of galaxies and the splashback feature in clusters selected by the Sunyaev-Zel'dovich effect from the Advanced Atacama Cosmology Telescope (AdvACT) survey using galaxies observed by the Dark Energy Survey (DES). The splashback radius is consistent with CDM-only simulations and is located at . We split the galaxies on color and find significant differences in their profile shapes. Red and green-valley galaxies show a splashback-like minimum in their slope profile consistent with theory, while the bluest galaxies show a weak feature at a smaller radius. We develop a mapping of galaxies to subhalos in simulations and assign colors based on infall time onto their hosts. We find that the shift in location of the steepest slope and different profile shapes can be mapped to the average time of infall of galaxies of different colors. The steepest slope traces a discontinuity in the phase space of dark matter halos. By relating spatial profiles to infall time, we can use splashback as a clock to understand galaxy quenching. We find that red galaxies have on average been in clusters over 3.2 Gyr, green galaxies about 2.2 Gyr, while blue galaxies have been accreted most recently and have not reached apocenter. Using the full radial profiles, we fit a simple quenching model and find that the onset of galaxy quenching occurs after a delay of about a gigayear and that galaxies quench rapidly thereafter with an exponential timescale of 0.6 Gyr
Genetic influences on schizophrenia and subcortical brain volumes:Large-scale proof of concept
Schizophrenia is a devastating psychiatric illness with high heritability. Brain structure and function differ, on average, between people with schizophrenia and healthy individuals. As common genetic associations are emerging for both schizophrenia and brain imaging phenotypes, we can now use genome-wide data to investigate genetic overlap. Here we integrated results from common variant studies of schizophrenia (33,636 cases, 43,008 controls) and volumes of several (mainly subcortical) brain structures (11,840 subjects). We did not find evidence of genetic overlap between schizophrenia risk and subcortical volume measures either at the level of common variant genetic architecture or for single genetic markers. These results provide a proof of concept (albeit based on a limited set of structural brain measures) and define a roadmap for future studies investigating the genetic covariance between structural or functional brain phenotypes and risk for psychiatric disorders