Amphibian skin defences show variation in ability to inhibit growth of Batrachochytrium dendrobatidis isolates from the Global Panzootic Lineage

The fungal pathogen Batrachochytrium dendrobatidis has caused declines and extinctions in hundreds of amphibian species across the world. Virulence varies among and within lineages; the Global Panzootic Lineage (GPL) is the most pathogenic, although there is also variation in lethality between GPL isolates. Amphibians have a number of defences against pathogens, and skin products including the microbiota and host peptides have been shown to have considerable influence over disease progression. Here we show the collective skin products (the mucosome) of two amphibian species show significant variation in their ability to inhibit different globally- distributed isolates of GPL. This may in part explain the variation in disease susceptibility of hosts to different strains of Batrachochytrium dendrobatidis. More work is required to identify particular traits associated with mucosomes that confer broad- spectrum inhibition across GPL in order to facilitate the development of prophylaxis and/or treatments for chytridiomycosis in situ

Gauge Independence of Limiting Cases of One-Loop Electron Dispersion Relation in High-Temperature QED

Assuming high temperature and taking subleading temperature dependence into account, gauge dependence of one-loop electron dispersion relation is investigated in massless QED at zero chemical potential. The analysis is carried out using a general linear covariant gauge. The equation governing the gauge dependence of the dispersion relation is obtained and used to prove that the dispersion relation is gauge independent in the limiting case of momenta much larger than $eT$. It is also shown that the effective mass is not influenced by the leading temperature dependence of the gauge dependent part of the effective self-energy. As a result the effective mass, which is of order $eT$, does not receive a correction of order $e^2T$ from one loop, independent of the gauge parameter.Comment: Revised and enlarged version, 14 pages, Revte

Thermal Pions ns Isospin Chemical Potential Effects

The density corrections, in terms of the isospin chemical potential $\mu_I$, to the mass of the pions are investigated in the framework of the SU(2) low energy effective chiral invariant lagrangian. As a function of temperature and $\mu_I =0$, the mass remains quite stable, starting to grow for very high values of $T$, confirming previous results. However, the dependence for a non-vanishing chemical potential turns out to be much more dramatic. In particular, there are interesting corrections to the mass when both effects (temperature and chemical potential) are simultaneously present. At zero temperature the $\pi ^{\pm}$ should condensate when $\mu_{I} = \mp m_{\pi}$. This is not longer valid anymore at finite $T$. The mass of the $\pi_0$ acquires also a non trivial dependence on $\mu_I$ at finite $T$.Comment: 5 pages, 2 figures. To appear in the proceedings of the International High-Energy Physics Conference on Quantum Chromodynamics QCD02, Montpellier, 2-9 July (2002

Practices of strength and conditioning coaches across Chinese high–performance sports

This study used an online survey to investigate the practices and perspectives of strength and conditioning coaches (SCCs) across different high–performance sports in China. The survey comprised of the following sections: (a) background information, (b) muscular strength and power, (c) speed, (d) endurance, (e) plyometrics, (f) flexibility, (g) physical testing, (h) technology use, and (i) programing. In total, 93 SCCs from 44 high–performance sports across 25 provinces/municipalities participated in this study (age 31.5 ± 6.9 yrs, experience as a SCC 5.5 ± 4.4 yrs). Periodization strategies were used by 97% of SCCs. Clean and derivatives (37%) were deemed the most important exercises for strength and power development. Heart rate (85%) and repetition maximum (72%) were the most used methods for determining set loads in endurance and strength training, respectively. Box drills (91%) were the most prescribed plyometric exercise, and dynamic stretching (91%) was the most prescribed flexibility exercise. All SCCs physically tested their athletes and 95% frequently used technology–based equipment. For open–ended questions, 30% of SCCs would change their programs by improving monitoring, testing, equipment, and facilities. Thirty-nine percent of SCCs believed digitization and monitoring will be prominent future trends. The results indicated that most practices of SCCs in Chinese high performance–sports were dissimilar to those of SCCs in other countries. SCCs generally prescribe training according to the needs of sports. However, the interferences of many external factors also affected the scientific nature of training prescription

Physical profiling of international cricket players: an investigation between bowlers and batters

Objective: This study aims to develop a physical profile of international cricketers, and investigate if positional differences exist between bowlers and batters. Methods: Nineteen, international male cricketers, eleven bowlers (age 24.1 ± 5.2 years; height 179.73 ± 5.27 cm; weight 73.64 ± 6.65 kg), and eight batters (age 22.9 ± 3.8 years; height 180.25 ± 5.57 cm; weight 77.01 ± 8.99 kg) participated in this study. The physical test battery included; power, speed, strength and aerobic fitness tests. Results: Batters demonstrated significantly higher scores for the countermovement jump (p < 0.03; ES = -1.55) and squat jump (p < 0.03; ES = -0.98). Batters showed non-significant but small ES for faster 0-5 m (ES = 0.40) and 0-10 m (ES = 0.35) sprint times, superior hand grip strength (ES = -0.20), and higher Yo-Yo intermittent recovery test scores (ES = -0.46). Bowlers showed non-significant but small ES for faster 5 km time trials (ES = -0.51), lower bodyweight (ES = -0.42) and body fat percentage (ES = -0.30). Intra-positional (i.e., seam and spin bowlers) and individual differences amongst players were observed. Conclusion: This study provides a physical profile of international cricketers. Batters demonstrated superior lower-body power compared to bowlers and other physical test results were similar across positions. However, individual scores for each physical test demonstrated that differences exist amongst players. This should be accounted for by strength and conditioning coaches when using physical profiling data to inform the design and evaluation of their programs

Light-front Schwinger Model at Finite Temperature

We study the light-front Schwinger model at finite temperature following the recent proposal in \cite{alves}. We show that the calculations are carried out efficiently by working with the full propagator for the fermion, which also avoids subtleties that arise with light-front regularizations. We demonstrate this with the calculation of the zero temperature anomaly. We show that temperature dependent corrections to the anomaly vanish, consistent with the results from the calculations in the conventional quantization. The gauge self-energy is seen to have the expected non-analytic behavior at finite temperature, but does not quite coincide with the conventional results. However, the two structures are exactly the same on-shell. We show that temperature does not modify the bound state equations and that the fermion condensate has the same behavior at finite temperature as that obtained in the conventional quantization.Comment: 10 pages, one figure, version to be published in Phys. Rev.

Suppression of Bremsstrahlung at Non-Zero Temperature

The first-order bremsstrahlung emission spectrum is $\alpha d\omega/\omega$ at zero temperature. If the radiation is emitted into a region that contains a thermal distribution of photons, then the rate is increased by a factor $1+N(\omega)$ where $N(\omega)$ is the Bose-Einstein function. The stimulated emission changes the spectrum to $\alpha Td\omega/\omega^{2}$ for $\omega\ll T$. If this were correct, an infinite amount of energy would be radiated in the low frequency modes. This unphysical result indicates a breakdown of perturbation theory. The paper computes the bremsstrahlung rate to all orders of perturbation theory, neglecting the recoil of the charged particle. When the perturbation series is summed, it has a different low-energy behavior. For $\omega\ll\alpha T$, the spectrum is independent of $\omega$ and has a value proportional to $d\omega/\alpha T$ .Comment: 16 pages (plain TeX), figures available on reques

Contemporary practices of strength and conditioning coaches in professional cricket

This study describes the contemporary practices of strength and conditioning (S&C) coaches in male professional cricket. Thirty-three S&C coaches working with international and professional club teams across seven countries completed an online survey. The survey consisted of 45 questions (35 fixed responses and 10 open-ended), with eight sections: (a) background information, (b) muscular strength and power development, (c) speed development, (d) plyometrics, (e) flexibility development, (f) physical testing, (g) technology use, and (h) programing. Most S&C coaches were educated to degree level (97%) or higher, with 91% of degrees being in a sports science related field. Whereas, 73% held S&C and 40% cricket coaching certifications. Isometric type resistance training exercises (94%) were frequently programed by S&C coaches, with squats and deadlifts (including variations) deemed the most important strength development exercises. Ratings of perceived exertion (58%) was most used for determining set loads. Hang clean (64%) and multiple hops/lunges (85%) were the most prescribed Olympic weightlifting and plyometric exercises. Speed gates (85%) were the most used technology-based equipment. Open-ended questions revealed, 45% of S&C coaches believed time constraints, scheduling and fixtures are the main issues faced in their role. Position specific demands (61%) was the predominant method used for individualizing players training strategies. The information presented in this study is valuable for those pursuing or currently working as a S&C coach in professional cricket to align, compare and explain their practices. Furthermore, will provide insight for the wider athlete support team (i.e., sports coaches, physiotherapists) on the practices of S&C coaches

Apparatus and method for deforming a workpiece

An apparatus and method is provided for controlling the temperature of dies and workpiece throughout a deformation process. Dies are capable of receiving external current to resistively heat the workpiece and dies during the deformation operation, the external current being modulated by feedback temperature readings taken from the workpiece. External current may be provided from a homopolar generator capable of producing pulsed dc current at controllable intervals and magnitudes simultaneously through the dies and workpiece.Board of Regents, University of Texas Syste

3-dimensional Rules for Finite-Temperature Loops

We present simple diagrammatic rules to write down Euclidean n-point functions at finite temperature directly in terms of 3-dimensional momentum integrals, without ever performing a single Matsubara sum. The rules can be understood as describing the interaction of the external particles with those of the thermal bath.Comment: 12 pages, 4 figures, to appear in Physics Letters