191 research outputs found
Rapidity gaps at HERA and the Tevatron from soft colour exchanges
Models based on soft colour exchanges to rearrange colour strings in the
final state provide a general framework for both diffractive and
non-diffractive events in ep and hadron-hadron collisions. We study two such
models and find that they can reproduce rapidity gap data from both HERA and
the Tevatron. We also discuss the influence of parton cascades and multiple
interactions on the results.Comment: 4 pages, 4 EPS figures, presented at UK Phenomenology Workshop on
Collider Physics, Durham. Uses iopart.cl
Efficacy of different recovery strategies in elite soccer players
Una correcta estrategia de recuperación (ER) tras la competición o el entrenamiento de alta intensidad en fútbol ayudará a no disminuir el rendimiento y a prevenir lesiones. El objetivo de este trabajo fue estudiar la eficacia de diferentes estrategias de recuperación combinadas en comparación con una simple, tras una sesión de entrenamiento específico de fútbol. Participaron 20 jugadores de fútbol de élite y se utilizaron cuatro estrategias de recuperación de forma aleatoria y contrabalanceada a lo largo de 4 semanas de entrenamiento. Se midió temperatura timpánica y las escalas subjetiva Total
Quality Recovery (TQR) y Category Ratio Scale (CR10). Los resultados exponen que ninguna de las ER estudiadas muestra ser más eficaz que las demás. No obstante, la realización de protocolos de recuperación combinados llevados a cabo tras la sesión de entrenamiento de fútbol, tiende a una mayor eficacia respecto al protocolo que incluía únicamente estiramientosAfter a soccer match or high intensity training, suitable recovery will help not to decrease performance and to prevent injuries. The aim of this study was to test the effectiveness of different combined recovery strategies in comparison with a simple one, after a specific soccer training session. Twenty elite players participated in the study. A randomized crossover design was used to determine the effect of 4 post-training session recovery strategies. Tympanic temperature was measured, as well as Total Quality Recovery (TQR) and Category Ratio Scale (CR10) subjective scales. Results show that none of the recovery strategies proved more effective than others. However, the use of combined strategies tended to be more effective than a simple strategy after a high intensity training session in socce
Physiological responses in a simulated canarian wrestling contest
La Lucha Canaria (LC) ha sido recientemente reconocida como deporte por el Consejo Superior de Deportes, aunque su origen se pierde en el tiempo. Sin embargo, no hay ningún trabajo en la bibliografía científica que describa qué ocurre fisiológicamente durante la competición en esta modalidad de lucha, y éste es el objetivo del presente trabajo. Con una muestra de 12 luchadores de alto nivel (puntales) simulamos el sistema de competición actual en Lucha Canaria. Se estudió la frecuencia cardiaca, la tensión arterial y la concentración de lactato en sangre en diferentes momentos de la simulación. Los patrones observados de respuesta de FC, TA y lactato, caracterizan a la competición en LC como un ejercicio intermitente, con picos de intensidad que superan el umbral láctico y determinan incrementos importantes de FC y TA sistólica. Este estudio es el primero en que se valora la respuesta fisiológica del luchador canario en competición.The aim of this article is to describe what happens from a physiological point of view in a Canarian Wrestling (CW) contest. The Spanish National Sports Council recognized Canarian Wrestling as a sport on June 1st, 2009, although its origin is not very well documented. No scientific article exists in the scientific literature to describe what happens physiologically during a CW contest. Twelve high level wrestlers were recruited to simulate a CW match. The study involved data about heart rate (HR), blood pressure (BP) and blood lactate levels (L) at different moments of the combat. The conclusions of the data observed concerning HR, BP and L classify Canarian Wrestling as an intermittent exercise, with intensity peaks that exceed the lactic threshold and high levels of HR and systolic BP. This is the first paper in which the physiological responses in a Canarian Wrestling competition are reported
Applications of QCD
Talk given at XIXth International Symposium on Lepton and Photon Interactions
at High Energies (LP 99), Stanford, California, 9-14 August 1999.Comment: latex, 26 page
Regge Analysis of Diffractive and Leading Baryon Structure Functions from DIS
In this paper we present a combined analysis of the H1 data on leading baryon
and diffractive structure functions from DIS, which are handled as two
components of the same semi-inclusive process. The available structure function
data are analyzed in a series of fits in which three main exchanges are taking
into account: pomeron, reggeon and pion. For each of these contributions, Regge
factorization of the correspondent structure function is assumed. By this
procedure, we extract information about the interface between the diffractive,
pomeron-dominated, region and the leading proton spectrum, which is mostly
ruled by secondary exchanges. One of the main results is that the relative
reggeon contribution to the semi-inclusive structure function is much smaller
than the one obtained from a analysis of the diffractive structure function
alone.Comment: ps file, 22 pages, 5 figures. Totally revised version with major
changes, to appear in Physical Review
Charged Particle Multiplicity in Diffractive Deep Inelastic Scattering
The recent data from H1 Collaboration on hadron multiplicity in diffractive
DIS has been studied in the framework of perturbative QCD as a function of
invariant diffractive mass. The formulas obtained explain the observed excess
of particle production in diffractive DIS relative to that in DIS and
annihilation. It is shown that the results are sensitive to the quark--gluon
structure of the Pomeron. Namely, the data say in favour of a super-hard gluon
distribution at the initial scale.Comment: 12 pages, 3 figures; to be published in Phys. Rev.
Diffractive Photoproduction in the Framework of Fracture Functions
Recent data on diffractive photoproduction of dijets are analyzed within the
framework of fracture functions and paying special attention to the
consequences of the use of different rapidity gap definitions in order to
identify diffractive events. Although these effects are found to be
significant, it is shown that once they are properly taken into account, a very
precise agreement between diffractive DIS and diffractive dijet photoproduction
emerges without any significant hint of hard factorization breaking.Comment: 13 pages, 4 figures. To appear in Phys.Rev.
The QCD description of diffractive processes
We review the application of perturbative QCD to diffractive processes. We
introduce the two gluon exchange model to describe diffractive qq(bar) and
qq(bar)g production in deep inelastic scattering. We study the triple Regge
limit and briefly consider multiple gluon exchange. We discuss diffractive
vector meson production at HERA both at t = 0 and large |t|. We demonstrate the
non-factorization of diffractive processes at hadron colliders.Comment: 39 pages, 14 figures, LaTeX, new references added and some discussion
clarifie
A Short-Term Resistance Training Circuit Improved Antioxidants in Sedentary Adults with Down Syndrome
Previous studies have found aerobic training improved oxidative damage in people with Down syndrome (DS). However, there is a lack of information regarding the influence of resistance training on redox imbalance in this population. Accordingly, this study was conducted to determine the effect of resistance training (RT) on antioxidant defence system in sedentary adults with DS. Thirty-six male adults with DS were recruited through different community support groups. Eighteen were randomly assigned to perform a circuit RT program with 6 stations, 3 days/week for 12 weeks. Plasma total antioxidant status (TAS), reduced glutathione (GHS), ascorbate, serum alpha-tocopherol, and erythrocyte glutathione reductase activity were assessed. Plasma malondialdehyde (MDA) and carbonyl groups (CG) were assessed as markers of oxidative damage. Muscle strength was also measured. Dynamic torque of knee extensors and flexors as well as maximal handgrip strength was significantly improved after the completion of the training program. Plasma levels of TAS and erythrocyte glutathione reductase (GR) activity were significantly increased. Conversely, MDA and CG levels were significantly reduced. It was concluded RT improved antioxidant defence system and reduced oxidative damage in adults with DS. Further, long-term studies are required to determine whether the increased antioxidant system may improve clinical outcomes of adults with DS
Soft Color Interactions and Diffractive Hard Scattering at the Fermilab Tevatron
An improved understanding of nonperturbative QCD can be obtained by the
recently developed soft color interaction models. Their essence is the
variation of color string-field topologies, giving a unified description of
final states in high energy interactions, e.g., diffractive and nondiffractive
events in ep and ppbar. Here we present a detailed study of such models (the
soft color interaction model and the generalized area law model) applied to
ppbar, considering also the general problem of the underlying event including
beam particle remnants. With models tuned to HERA ep data, we find a good
description also of Tevatron data on production of W, beauty and jets in
diffractive events defined either by leading antiprotons or by one or two
rapidity gaps in the forward or backward regions. We also give predictions for
diffractive J/psi production where the soft exchange mechanism produces both a
gap and a color singlet ccbar state in the same event. This soft color
interaction approach is also compared with Pomeron-based models for
diffraction, and some possibilities to experimentally discriminate between
these different approaches are discussed.Comment: 35 pages, 15 figures, uses REVTeX. Minor changes, version to appear
in Phys. Rev.
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