Global practitioner assessment and management of mental fatigue and mental recovery in high-performance sport : A need for evidence-based best-practice guidelines

Background Mental fatigue and mental recovery have gained scientific attention in relation to sporting performance, yet best practice assessment and management methods are lacking. A greater understanding of current knowledge and practices in high-performance sport are necessary. Objective To understand the contemporary knowledge, beliefs, monitoring processes, management strategies, perceived responsibility, sources of evidence, and challenges, when assessing the mental fatigue and mental recovery of athletes in high-performance sport. Methods A mixed-methods survey approach obtained information from 156 multi-disciplinary high-performance sport practitioners. Descriptive outputs were reported and potential differences between key concepts were detected using Wilcoxon-signed rank analysis. Thematic analysis interpreted open-text responses. Results Only 11.5% and 5.1% of respondents indicated they were “very” knowledgeable about mental fatigue and mental recovery, respectively. Knowledge (p < 0.001) and confidence in application (p = 0.001) were significantly greater for mental fatigue than mental recovery. Nearly all respondents perceived mental fatigue and mental recovery impacted training and competition performance, with a greater negative impact during competition (p < 0.001). A limited number of respondents reported deliberate assessment (31.1%) or management (51.2%) of mental fatigue and mental recovery. A combination of sources of evidence were used to inform practice, with common challenges to implementation including staff knowledge, athlete-buy in, time-availability, and a lack of evidence. Practitioners reported that assessing and managing mental fatigue and mental recovery was multi-disciplinary in nature. Conclusion Practitioners reported that mental fatigue and mental recovery did impact performance, yet this was not reflected in the implementation of evidence-based assessment and management practices in high-performance sport

Scattering of Cosmic Rays by Magnetohydrodynamic Interstellar Turbulence

Recent advances in understanding of magnetohydrodynamic (MHD) turbulence call for substantial revisions in our understanding of cosmic ray transport. In this paper we use gyroresonance recently obtained scaling laws for MHD modes to calculate the scattering frequency for cosmic rays in the ISM. We consider gyroresonance with MHD modes (Alfvenic, slow and fast) and transit-time damping (TTD) by fast modes. We conclude that the gyroresonance with fast modes is the dominant contribution to cosmic ray scattering for the typical interstellar conditions. In contrast to earlier studies, we find that Alfvenic and slow modes are inefficient because they are far from isotropy usually assumed.Comment: 4 pages, 2 figures, Phys. Rev. Lett. in press, minor change

Mueller Matrix Parameters for Radio Telescopes and their Observational Determination

Modern digital crosscorrelators permit the simultaneous measurement of all four Stokes parameters. However, the results must be calibrated to correct for the polarization transfer function of the receiving system. The transfer function for any device can be expressed by its Mueller matrix. We express the matrix elements in terms of fundamental system parameters that describe the voltage transfer functions (known as the Jones matrix) of the various system devices in physical terms and thus provide a means for comparing with engineering calculations and investigating the effects of design changes. We describe how to determine these parameters with astronomical observations. We illustrate the method by applying it to some of the receivers at the Arecibo Observatory.Comment: 23 pages, 2 figures; accepted for PAS

Detection and analysis of new psittacine beak and feather disease virus (PBFDv) nucleotide sequences

ΔΕΝ ΥΠΑΡΧΕΙ ΠΕΡΙΛΗΨΗPsittacine beak and feather disease (PBFD) affects a large number of Psittaciformes species. In this study, five White Cockatoo parrots (Cacatua alba) with clinical signs of PBFD were examined. After euthanasia, a full necropsy of parrots was performed and organs with macroscopic changes were sampled for routine histopathological evaluation. To confirm the presence of psittacine beak and feather disease virus (PBFDv), feather samples were analyzed with the PCR method. Sequence analysis of the obtained PCR products indicated their close relationship (99%) to other PBFDv isolates. Six variable nucleotide sites were discovered, two missense and four silent mutations. This paper presents the evidence of new PBFDv sequence in Cockatoo species

The Large Magellanic Cloud: A power spectral analysis of Spitzer images

We present a power spectral analysis of Spitzer images of the Large Magellanic Cloud. The power spectra of the FIR emission show two different power laws. At larger scales (kpc) the slope is ~ -1.6, while at smaller ones (tens to few hundreds of parsecs) the slope is steeper, with a value ~ -2.9. The break occurs at a scale around 100-200 pc. We interpret this break as the scale height of the dust disk of the LMC. We perform high resolution simulations with and without stellar feedback. Our AMR hydrodynamic simulations of model galaxies using the LMC mass and rotation curve, confirm that they have similar two-component power-laws for projected density and that the break does indeed occur at the disk thickness. Power spectral analysis of velocities betrays a single power law for in-plane components. The vertical component of the velocity shows a flat behavior for large structures and a power law similar to the in-plane velocities at small scales. The motions are highly anisotropic at large scales, with in-plane velocities being much more important than vertical ones. In contrast, at small scales, the motions become more isotropic.Comment: 8 pages, 4 figures, talk presented at "Galaxies and their Masks", celebrating Ken Freeman's 70-th birthday, Sossusvlei, Namibia, April 2010. To be published by Springer, New York, editors D.L. Block, K.C. Freeman, & I. Puerar

Discovery of a new Transient X-ray Pulsar in the Small Magellanic Cloud

Rossi X-Ray Timing Explorer observations of the Small Magellanic Cloud have revealed a previously unknown transient X-ray pulsar with a pulse period of 95s. Provisionally designated XTE SMC95, the pulsar was detected in three Proportional Counter Array observations during an outburst spanning 4 weeks in March/April 1999. The pulse profile is double peaked reaching a pulse fraction \~0.8. The source is proposed as a Be/neutron star system on the basis of its pulsations, transient nature and characteristically hard X-ray spectrum. The 2-10 keV X-ray luminosity implied by our observations is > 2x10^37 erg/s which is consistent with that of normal outbursts seen in Galactic systems. This discovery adds to the emerging picture of the SMC as containing an extremely dense population of transient high mass X-ray binaries.Comment: Accepted by A&A. 7 pages, 6 figure

A high fat diet induces sex-specific differences in hepatic lipid metabolism and nitrite/nitrate in rats

This work is supported by the grants No.173033 and III41028 from the Ministry of Science, Republic of Serbia.Men and women differ substantially in regard to the severity of insulin resistance (IR) but the underlying mechanism(s) of how this occurs is poorly characterized. We investigated whether a high fat (HF) diet resulted in sex-specific differences in nitrite/nitrate production and lipid metabolism and whether these variances may contribute to altered obesity-induced IR. Male and female Wistar rats were fed a standard laboratory diet or a HF diet for 10 weeks. The level of plasma nitrite/nitrate, as well as free fatty acid (FFA), in both plasma and liver lysates were assessed. The levels of inducible nitric oxide (NO) synthase (iNOS), p65 subunit of NFκB, total and phosphorylated forms of Akt, mTOR and PDK-1 in lysates, and the levels of glucose transporter 2 (Glut-2) and fatty acid translocase/cluster of differentiation 36 (FAT/CD36) in plasma membrane fractions of liver were assessed. HF-fed male rats exhibited a significant increase in plasma nitrite/nitrate, and hepatic FFA and FAT/CD36 levels compared with controls. They also displayed a relative decrease in iNOS and Glut-2 levels in the liver. Phosphorylation of Akt (at Ser473 and Thr308), mTOR and PDK-1 was also reduced. HF-fed female rats exhibited increased levels of NFκB-p65 in liver compared with controls, while levels of Glut-2, FAT/CD36 and Akt phosphorylation at Thr308 and PDK-1 were decreased. Our results reveal that altered lipid and glucose metabolism in obesity, lead to altered iNOS expression and nitrite/nitrate production. It is likely that this mechanism contributes to sex-specific differences in the development of IR.PostprintPeer reviewe