Differences in conditions of employment between sport managers with and without degree in physical activity and sport sciences

Objetivo: Analizar las diferencias laborales existentes entre los gestores deportivoscon estudios universitarios relacionados con las Ciencias de la Actividad Física y el Deporte respecto a los que no tienen esta titulación. Material y métodos: La muestra estuvo compuesta por 268gestores que desarrollan su actividadprincipal en centros deportivosen España (=34,38 años; DT=6,68). Se segmentó la muestra en dos grupos: profesionales con titulación Universitariaen Ciencias de la Actividad Física y el Deporte (n=104) y; profesionales que no poseíanesta titulación (n=164).Resultados:Los titulados universitarios son significativamente (p2.000 m2). Además,presentan una mayor intención de abandono de la empresa o del sector. Por el contrario, la formación no es un factor determinante en el género de los sujetos o en la cantidad de salario mensual percibido. Conclusiones:Para evitar el modelo de intrusismo desleal que incorpora a gestores deportivos poco cualificados y perjudica la imagen y derecho de los profesionales con titulación, se precisa de una adecuada regulación de favor del profesional con titulación de Ciencias de la Actividad Física y el Deporteen España que aglutine los mismos criterios.Esto ayudaría a las organizaciones deportivas a fidelizar a su personal con titulación universitaria en Ciencias de la Actividad Física y el Deporte.ObjectiveAnalyze existing in bachelor ́s degree labor differences between managers with college sports related Sciences of Physical Activity and Sport compared to those without this degree. Methods:The sample composed by268 managers who carry out their main activity in sports centers in Spain(=34.38 years, SD=6.68). The sample was segmented into two groups: professional that are graduates in Sport Sciences Degree (n=104) and, professionals who did not have this degree (n=164). Results:Graduates are significantly (p2,000 m2). Also, they have a higher intention to leave the company or the working sector. On the contrary, education is not a determining factor in the gender of the subjects or in the monthly salary. Conclusions:In order to avoid the unfair professional intrusion model that incorporates low-skilled managers and damage the image and rights of managers with university degree, a proper regulation that gathers the same criteria of the professional qualifications of Sciences of Physical Activity and Sport in Spain is required. This would help to sports organizations to retain their staff with university degree in Sciences of Physical Activity and Sport

Aplicación de la dinamometría isocinética para establecer perfiles de riesgo de lesión isquiosural en futbolistas profesionales. [The use of isokinetic dynamometry to establish risk profiles of hamstring injury in professional football players].

<p align="justify">Las lesiones en la musculatura isquiosural son frecuentes en el fútbol profesional y han sido relacionadas con el desequilibrio entre la fuerza de los flexores y extensores de rodilla. El objetivo de nuestro estudio fue comprobar si la ratio de fuerza máxima excéntrica de flexores/concéntrica de extensores (ratio Flexexc30/Extcon240) y el ángulo de rodilla donde la musculatura isquiosural alcanza su máximo momento de fuerza, son variables útiles para establecer perfiles de riesgo de lesión isquiosural en futbolistas profesionales. Veinte jugadores de un equipo de la Segunda División de la Liga de Fútbol Profesional realizaron bilateralmente un test isocinético de flexión excéntrica de rodilla a 30º/s y extensión concéntrica de rodilla a 240º/s durante la pretemporada. Tras calcular la ratio Flexexc30/Extcon240 y el ángulo de máximo momento de fuerza, se registraron las lesiones sufridas por los jugadores a lo largo de la temporada. Los resultados mostraron que dos de los cinco jugadores lesionados presentaron ratios Flexexc30/Extcon240 menores de 0.89, valor que ha sido utilizado previamente para determinar el desequilibrio entre la musculatura flexora y extensora de rodilla y el riesgo de lesión (Croisier, Ganteaume, Binet, Genty, y Ferret, 2008). Además, otros dos de los jugadores lesionados obtuvieron ratios entre 0.93 y 1.00. Por otro lado, no se encontraron diferencias en el ángulo de máximo momento de fuerza entre jugadores lesionados y no lesionados. Estos resultados indican que la ratio Flexexc30/Extcon240 puede ser un índice útil para determinar el riesgo de lesión isquiosural en futbolistas profesionales.</p>Abstract<p align="justify">Hamstring injuries are common in professional football and have been related to the imbalance between knee flexor and extensor strength. The aim of our study was to establish whether the flexor eccentric/extensor concentric strength ratio (Flexexc30/Extcon240 ratio) and the knee angle where the peak torque of the hamstring musculature was found, are useful variables to establish risk profiles for hamstring injury in professional football players. Twenty players of a Second Division team of the Liga de Fútbol Profesional bilaterally performed an isokinetic test of eccentric knee flexion at 30º/s and concentric knee extension at 240º/s during the pre-season. The Flexexc30/Extcon240 ratio and the knee angle of peak torque were calculated, and the players’ injuries were registered throughout the season. The results showed that two of the five injured players had Flexexc30/Extcon240 ratios lower than 0.89, value that has been previously used to determine the imbalance between knee flexor and extensor strength and the risk of injury (Croisier, Ganteaume, Binet, Genty, and Ferret, 2008). In addition, another two injured players obtained ratios between 0.93 and 1.00. On the other hand, no differences in the knee angle of peak torque between injured and non-injured players were found. These results indicate that the Flexexc30/Extcon240 ratio may be a useful index to determine the risk of hamstring injury in professional football players.</p>http://dx.doi.org/10.5232/ricyde2013.0340

Waiting for Unruh

How long does a uniformly accelerated observer need to interact with a quantum field in order to record thermality in the Unruh temperature? We address this question for a pointlike Unruh–DeWitt detector, coupled linearly to a real Klein–Gordon field of mass and treated within first order perturbation theory, in the limit of large detector energy gap . We first show that when the interaction duration is fixed, thermality in the sense of detailed balance cannot hold as , and this property generalises from the Unruh effect to any Kubo–Martin–Schwinger state satisfying certain technical conditions. We then specialise to a massless field in four spacetime dimensions and show that detailed balance does hold when grows as a power-law in as , provided the switch-on and switch-off intervals are stretched proportionally to and the switching function has sufficiently strong Fourier decay. By contrast, if grows by stretching a plateau in which the interaction remains at constant strength but keeping the duration of the switch-on and switch-off intervals fixed, detailed balance at requires to grow faster than any polynomial in , under mild technical conditions. The results also hold for a static detector in a Minkowski heat bath. The results limit the utility of the large regime as a probe of thermality in time-dependent versions of the Hawking and Unruh effects, such as an observer falling into a radiating black hole. They may also have implications on the design of prospective experimental tests of the Unruh effect

Entropy bounds in terms of the w parameter

In a pair of recent articles [PRL 105 (2010) 041302 - arXiv:1005.1132; JHEP 1103 (2011) 056 - arXiv:1012.2867] two of the current authors have developed an entropy bound for equilibrium uncollapsed matter using only classical general relativity, basic thermodynamics, and the Unruh effect. An odd feature of that bound, S <= A/2, was that the proportionality constant, 1/2, was weaker than that expected from black hole thermodynamics, 1/4. In the current article we strengthen the previous results by obtaining a bound involving the (suitably averaged) w parameter. Simple causality arguments restrict this averaged parameter to be <= 1. When equality holds, the entropy bound saturates at the value expected based on black hole thermodynamics. We also add some clarifying comments regarding the (net) positivity of the chemical potential. Overall, we find that even in the absence of any black hole region, we can nevertheless get arbitrarily close to the Bekenstein entropy.Comment: V1: 14 pages. V2: One reference added. V3: This version accepted for publication in JHE

Particle creation rate for dynamical black holes

We present the particle creation probability rate around a general black hole as an outcome of quantum fluctuations. Using the uncertainty principle for these fluctuation, we derive a new ultraviolet frequency cutoff for the radiation spectrum of a dynamical black hole. Using this frequency cutoff, we define the probability creation rate function for such black holes. We consider a dynamical Vaidya model, and calculate the probability creation rate for this case when its horizon is in a slowly evolving phase. Our results show that one can expect the usual Hawking radiation emission process in the case of a dynamical black hole when it has a slowly evolving horizon. Moreover, calculating the probability rate for a dynamical black hole gives a measure of when Hawking radiation can be killed off by an incoming flux of matter or radiation. Our result strictly suggests that we have to revise the Hawking radiation expectation for primordial black holes that have grown substantially since they were created in the early universe. We also infer that this frequency cut off can be a parameter that shows the primordial black hole growth at the emission moment.Comment: 10 pages, 1 figure. The paper was rewritten in more clear presentation and one more appendix is adde

Environmental Wireless Sensor Network Deployment in Food Industry: from Theory to Practice

The difficulty behind Wireless Sensor Network deployments in industrial environments not only resides in the number of nodes or the communication protocols but also in the real location of the sensor nodes and the parameters to be monitored. Sensor soiling, high humidity and unreachable locations, among others, make real deployments a very difficult task to plan. Even though it is possible to find myriad approaches for floor planners and deployment tools in the state of the art, most of these problems are very difficult to model and foresee before actually deploying the network in the final scenario. This work shows two real deployments in food factories and how their problems are found and overcome

Conformally rescaled spacetimes and Hawking radiation

We study various derivations of Hawking radiation in conformally rescaled metrics. We focus on two important properties, the location of the horizon under a conformal transformation and its associated temperature. We find that the production of Hawking radiation cannot be associated in all cases to the trapping horizon because its location is not invariant under a conformal transformation. We also find evidence that the temperature of the Hawking radiation should transform simply under a conformal transformation, being invariant for asymptotic observers in the limit that the conformal transformation factor is unity at their location.Comment: 22 pages, version submitted to journa

Onset and decay of the 1 + 1 Hawking–Unruh effect: what the derivative-coupling detector saw

We study an Unruh–DeWitt particle detector that is coupled to the proper time derivative of a real scalar field in 1 + 1 spacetime dimensions. Working within first-order perturbation theory, we cast the transition probability into a regulator- free form, and we show that the transition rate remains well defined in the limit of sharp switching. The detector is insensitive to the infrared ambiguity when the field becomes massless, and we verify explicitly the regularity of the massless limit for a static detector in Minkowski half-space. We then consider a massless field for two scenarios of interest for the Hawking–Unruh effect: an inertial detector in Minkowski spacetime with an exponentially receding mirror, and an inertial detector in (1 + 1)-dimensional Schwarzschild spacetime, in the Hartle–Hawking–Israel and Unruh vacua. In the mirror spacetime the transition rate traces the onset of an energy flux from the mirror, with the expected Planckian late time asymptotics. In the Schwarzschild spacetime the transition rate of a detector that falls in from infinity gradually loses thermality, diverging near the singularity proportionally to r−3 2

Variations in task constraints shape emergent performance outcomes and complexity levels in balancing

This study investigated the extent to which specific interacting constraints of performance might increase or decrease the emergent complexity in a movement system, and whether this could affect the relationship between observed movement variability and the central nervous system's capacity to adapt to perturbations during balancing. Fifty-two healthy volunteers performed eight trials where different performance constraints were manipulated: task difficulty (three levels) and visual biofeedback conditions (with and without the center of pressure (COP) displacement and a target displayed). Balance performance was assessed using COP-based measures: mean velocity magnitude (MVM) and bivariate variable error (BVE). To assess the complexity of COP, fuzzy entropy (FE) and detrended fluctuation analysis (DFA) were computed. ANOVAs showed that MVM and BVE increased when task difficulty increased. During biofeedback conditions, individuals showed higher MVM but lower BVE at the easiest level of task difficulty. Overall, higher FE and lower DFA values were observed when biofeedback was available. On the other hand, FE reduced and DFA increased as difficulty level increased, in the presence of biofeedback. However, when biofeedback was not available, the opposite trend in FE and DFA values was observed. Regardless of changes to task constraints and the variable investigated, balance performance was positively related to complexity in every condition. Data revealed how specificity of task constraints can result in an increase or decrease in complexity emerging in a neurobiological system during balance performance

Heme oxygenase-1 regulates cell proliferation via carbon monoxide-mediated inhibition of T-type Ca2+ channels

Induction of the antioxidant enzyme heme oxygenase-1 (HO-1) affords cellular protection and suppresses proliferation of vascular smooth muscle cells (VSMCs) associated with a variety of pathological cardiovascular conditions including myocardial infarction and vascular injury. However, the underlying mechanisms are not fully understood. Over-expression of Cav3.2 T-type Ca2+ channels in HEK293 cells raised basal [Ca2+]i and increased proliferation as compared with non-transfected cells. Proliferation and [Ca2+]i levels were reduced to levels seen in non-transfected cells either by induction of HO-1 or exposure of cells to the HO-1 product, carbon monoxide (CO) (applied as the CO releasing molecule, CORM-3). In the aortic VSMC line A7r5, proliferation was also inhibited by induction of HO-1 or by exposure of cells to CO, and patch-clamp recordings indicated that CO inhibited T-type (as well as L-type) Ca2+ currents in these cells. Finally, in human saphenous vein smooth muscle cells, proliferation was reduced by T-type channel inhibition or by HO-1 induction or CO exposure. The effects of T-type channel blockade and HO-1 induction were non-additive. Collectively, these data indicate that HO-1 regulates proliferation via CO-mediated inhibition of T-type Ca2+ channels. This signalling pathway provides a novel means by which proliferation of VSMCs (and other cells) may be regulated therapeutically