406 research outputs found

    Physical rehabilitation in football by mechanical vibration and hypoxia

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    Las acciones explosivas en el fútbol se triplican respecto a los años 60, llegando a las 200-215 acciones explosivas/partido. Esto supone que la potencia muscular y la capacidad de recuperación sean factores limitantes, pudiendo ser frecuentes las lesiones musculares. Durante la lesión se pierden las cualidades condicionales, menos cuanto más corto sea este periodo. Existen diversos métodos para la mejora de la fuerza y capacidad de recuperación mediante las plataformas vibratorias y la hipoxia intermitente (HI). Mostramos resultados de una intervención con plataforma vibratoria y HI en futbolistas convalescientes de una rotura fibrilar. Este nuevo modelo de entrenamiento puede permitir mejoras la fuerza máxima (p<0,05) y capacidadde recuperación (p<0,05) ayudando en gran medida a no perder las cualidades condicionales.Explosive actions in football are three times over 60 years, reaching 200-215 explosive actions /match. This means that for an elite player, muscular power and resilience are performance limiting factors, which may be frequent muscular injuries. During the injury, conditional qualities are lost, the less the shorter the period. There are several methods for improving the strength and resilience, emphasizing the body vibration training and intermittent hypoxia (IH). In this study, results of an intervention HI vibrating platform and players who have been convalescing from a hamstring injury are shown. The results obtained suggest that this new training model allows for improvements in the levels of maximum force (p <0.05) and resilience (p <0.05). This helps keep the conditional qualities greatly

    Graben formation and dike arrest during the 2009 Harrat Lunayyir dike intrusion in Saudi Arabia: Insights from InSAR, stress calculations and analog experiments

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    Detailed spatial and temporal accounts of propagating dikes from crustal deformation data, including their interplay with faulting, are rare, leaving many questions about how this interplay affects graben formation and the arrest of dikes unanswered. Here we use interferometric synthetic aperture radar (InSAR) observations, stress calculations, and analog experiments to investigate the interaction between an intruding dike and normal faulting during the 2009 Harrat Lunayyir dike intrusion in western Saudi Arabia. We generated five displacement maps from InSAR data to unravel the temporal evolution of deformation covering the majority of the intrusion. We find that the observed surface displacements can be modeled by a ~2 m thick dike with an upper tip ~2\u2009km below the surface on 16 May 2009, 4\u2009weeks after the onset of seismic unrest. In the following three days, the dike propagated to within ~1\u2009km of the surface with graben\u2010bounding normal faulting dominating the near\u2010field deformation. The volume of the dike doubled between mid\u2010May and mid\u2010June. We carried out analog experiments that indicate that the wedge\u2010shaped graben grew outward with the faulting style changing progressively from normal faulting to oblique. Coulomb failure stress change calculations show that the intruding dike caused two zones of shallow horizontal tension on both sides of the dike, producing two zones of fissuring and normal faulting at the surface. In return, the faulting provoked compression around the upper tip of the dike, holding back its vertical propagation

    Machine Learning Can Predict the Timing and Size of Analog Earthquakes

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    Despite the growing spatiotemporal density of geophysical observations at subduction zones, predicting the timing and size of future earthquakes remains a challenge. Here we simulate multiple seismic cycles in a laboratory‐scale subduction zone. The model creates both partial and full margin ruptures, simulating magnitude M_w 6.2–8.3 earthquakes with a coefficient of variation in recurrence intervals of 0.5, similar to real subduction zones. We show that the common procedure of estimating the next earthquake size from slip‐deficit is unreliable. On the contrary, machine learning predicts well the timing and size of laboratory earthquakes by reconstructing and properly interpreting the spatiotemporally complex loading history of the system. These results promise substantial progress in real earthquake forecasting, as they suggest that the complex motion recorded by geodesists at subduction zones might be diagnostic of earthquake imminence

    Effect of training load on post-exercise cardiac troponin T elevations in young soccer players

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    Training load (TL) metrics are usually assessed to estimate the individual, physiological and psychological, acute, and adaptive responses to training. Cardiac troponins (cTn) reflect myocardial damage and are routinely analyzed for the clinical diagnosis of myocardial injury. The association between TL and post-exercise cTn elevations is scarcely investigated in young athletes, especially after playing common team sports such as soccer. The objective of this study was to assess the relationship between TL measurements during a small-sided soccer game and the subsequent increase in cTn in young players. Twenty male soccer players (age 11.9 ± 2 years, height 151 ± 13 cm, weight 43 ± 13 kg) were monitored during a 5 × 5 small-sided game and had blood samples drawn before, immediately after, and 3 h after exercise for a posterior analysis of high-sensitivity cardiac troponin T (hs-cTnT). Internal, external, and mixed metrics of TL were obtained from the rating of perceived exertion (RPE), heart rate (HR), and GPS player tracking. The results show that the concentration of hs-cTnT peaked at 3 h post-exercise in all participants. The magnitude of hs-cTnT elevation was mainly explained by the exercise duration in the maximal heart rate zone (Maximum Probability of Effect (MPE) = 92.5%), time in the high-speed zone (MPE = 90.4 %), and distance in the high-speed zone (MPE = 90.45%). Our results support the idea that common metrics of TL in soccer, easily obtained using player tracking systems, are strongly associated with the release of hs-cTnT in children and adolescents

    Cardiac troponin T release after football 7 in healthy children and adults

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    The objective of this study was to compare the release of cardiac troponin T (cTnT) after a football 7 match between two cohorts of children and adult players. Thirty-six male football players (children = 24, adult = 12) played a football 7 match, and cTnT was measured before, and 3 h after exercise. Concentrations of cTnT were compared between groups and time, and correlated with participants’ characteristics, as well as internal and external exercise load. Cardiac troponin T was elevated in all participants (p < 0.001), and exceeded the upper reference limit for myocardial infarction in 25 (~70%) of them. Baseline concentrations were higher in adults (p < 0.001), but the elevation of cTnT was comparable between the groups (p = 0.37). Age (p < 0.001), body mass (p = 0.001) and height (p < 0.001), and training experience (p = 0.001) were associated to baseline cTnT values, while distance (p < 0.001), mean speed (p < 0.001), and peak (p = 0.013) and mean (p = 0.016) heart rate were associated to the elevation of cTnT. The present study suggests that a football 7 match evoked elevations of cTnT during the subsequent hours in healthy players regardless of their age. However, adults might present higher resting values of cTnT than children. In addition, results suggest that the exercise-induced elevations of cTnT might be mediated by exercise load but not participant characteristics

    Binding site plasticity in viral PPxY Late domain recognition by the third WW domain of human NEDD4

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    The recognition of PPxY viral Late domains by the third WW domain of the HECT-E3 ubiquitin ligase NEDD4 (hNEDD4-WW3) is essential for the completion of the budding process of numerous enveloped viruses, including Ebola, Marburg, HTLV1 or Rabies. hNEDD4-WW3 has been validated as a promising target for the development of novel host-oriented broad spectrum antivirals. Nonetheless, finding inhibitors with good properties as therapeutic agents remains a challenge since the key determinants of binding affinity and specificity are still poorly understood. We present here a detailed structural and thermodynamic study of the interactions of hNEDD4-WW3 with viral Late domains combining isothermal titration calorimetry, NMR structural determination and molecular dynamics simulations. Structural and energetic differences in Late domain recognition reveal a highly plastic hNEDD4-WW3 binding site that can accommodate PPxY-containing ligands with varying orientations. These orientations are mostly determined by specific conformations adopted by residues I859 and T866. Our results suggest a conformational selection mechanism, extensive to other WW domains, and highlight the functional relevance of hNEDD4-WW3 domain conformational flexibility at the binding interface, which emerges as a key element to consider in the search for potent and selective inhibitors of therapeutic interest.This research has been financed by grants BIO2009-13261-C02, BIO2012-39922-CO2 and BIO2016-78746-C2-1-R from the Spanish Ministry of Education and Science (I.L.) including AEI/FEDER EU funds, by CTQ2017-83810-R grant (F.J.B) and by BFU2014-53787-P, the IRB Barcelona and the BBVA Foundation (M.J.M)

    Relationship Between Jump Capacity and Performance in BMX Cycling

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    The objective of this study is to assess the relationship between the results obtained on different vertical jump tests and the top score recorded during a BMX (Bicycle Moto-Cross) test and the rider''s performance. To do so, 10 BMX pilots participated in this study; 5 regarded as the elite group (EG) (age: 18.8 +/- 3.7, weight: 68.4 +/- 8.5 kg, height: 174 +/- 9 cm and previous BMX experience: 8 +/- 3.8 years) and 5 regarded as the recreational group (RG) (age: 19.8 +/- 4.8, weight: 69.2 +/- 11.7 kg, height: 170 +/- 9 cm, previous BMX experience: 4.2 +/- 1.3 years). Vertical jump capacity was obtained using the Bosco protocol, i.e. vertical squat jump (SJ), vertical countermovement jump (CMJ), drop jump (DJ) and repetitive jump (RJ), and time in race in a BMX circuit was determined. The results indicate a direct relationship between the time used to complete the circuit and the height of the jump reached in SJ (r: -.801; p:.017), CMJ (r : -.798; p :.018) and DJ (r : -.782; p:.022). This all suggests that assessing jump capacity using the Bosco test may be a useful tool for assessing BMX performance
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