Growing interfaces: A brief review on the tilt method

The tilt method applied to models of growing interfaces is a useful tool to characterize the nonlinearities of their associated equation. Growing interfaces with average slope $m$, in models and equations belonging to Kardar-Parisi-Zhang (KPZ) universality class, have average saturation velocity $\mathcal{V}_\mathrm{sat}=\Upsilon+\frac{1}{2}\Lambda\,m^2$ when $|m|\ll 1$. This property is sufficient to ensure that there is a nonlinearity type square height-gradient. Usually, the constant $\Lambda$ is considered equal to the nonlinear coefficient $\lambda$ of the KPZ equation. In this paper, we show that the mean square height-gradient $\langle |\nabla h|^2\rangle=a+b \,m^2$, where $b=1$ for the continuous KPZ equation and $b\neq 1$ otherwise, e.g. ballistic deposition (BD) and restricted-solid-on-solid (RSOS) models. In order to find the nonlinear coefficient $\lambda$ associated to each system, we establish the relationship $\Lambda=b\,\lambda$ and we test it through the discrete integration of the KPZ equation. We conclude that height-gradient fluctuations as function of $m^2$ are constant for continuous KPZ equation and increasing or decreasing in other systems, such as BD or RSOS models, respectively.Comment: 11 pages, 4 figure

Intervención psicológica en el entrenamiento deportivo : estrategias para optimizar el funcionamiento de jugadores de baloncesto en sesiones de ensayo repetitivo

Entre otros objetivos, la intervención psicológica en el ámbito del deporte de competición, puede contribuir a optimizar el funcionamiento de los deportistas en las sesiones de entrenamiento deportivo, favoreciendo el máximo aprovechamiento del tiempo de práctica. En este contexto, la incorporación de estrategias psicológicas al método habitual de entrenamiento, puede mejorar el rendimiento de los deportistas en los ejercicios de ensayo repetitivo de habilidades que se dominan, al incidir, favorablemente, en su motivación y atención durante estos ejercicios. El propósito de este estudio consistió en investigar si la combinación de tres estrategias psicológicas: establecimiento de objetivos de resultado intra-sujeto, registro de resultados y aplicación de contingencias relacionadas con el resultado, afectaba al funcionamiento de jugadoras de baloncesto de alto nivel durante las sesiones de ensayo repetitivo de tiros a canasta. Para ello, se dividió a la muestra en tres grupos y se utilizó un diseño de línea-base múltiple. Los tres grupos fueron expuestos a una fase de línea-base y a una fase de intervención de diferente duración para cada grupo; y en la fase de intervención, a una condición de tratamiento, en la que se aplicaron las técnicas psicológicas, y a una condición de control. Los resultados mostraron que el rendimiento más alto se produjo en la condición de tratamiento durante la fase de intervención, sugiriendo la eficacia de las estrategias psicológicas para mejorar el funcionamiento de las deportistas. En la discusión se comentan las implicaciones de los datos hallados y el procedimiento utilizado en el contexto del entrenamiento deportivo.A major contribution of psychological intervention to competitive sport may be to enhance athletes' functioning during training sessions. In this context, to include psychological strategies within coaches' usual method of training may improve performance in sessions of mastered skills repetitive rehearsal, by increasing athletes' motivation and attention. The purpose of the present study consisted on investigating if a package of three psychological strategies: within-subject outcome goal-setting, outcome recording, and contingency management related to outcome, may affect performance of elite female basketball players during training sessions of shooting repetitive rehearsal. The sample was distributed in three groups of players, and a multiple baseline design was used including a baseline phase and an intervention phase both with different duration for each group, and also a treatment condition and a control condition within the intervention phase. Results showed the highest performance under the treatment condition during the intervention phase, suggesting the influence of the psychological strategies to enhance athletes' functioning. The author discusses the implications of these results and the procedure of the intervention in the context of sport training

Intervención psicológica con el equipo nacional olímpico de hockey hierba femenino

El equipo nacional olímpico de hockey hierba femenino de España ha llevado a cabo un intenso y completo plan de preparación con vistas a su participación en los Juegos Olímpicos de Barcelona. Entre las parcelas de trabajo que ha contemplado el plan, la intervención psicológica ha ocupado un destacado lugar, con un psicólogo, el primer autor, formando parte, permanentemente, del cuadro técnico bajo la responsabilidad global del entrenador principal y otro especialista, el segundo autor, actuando como asesor. La intervención ha estado coordinada, en todo momento, con el plan de entrenamiento deportivo del equipo, teniendo en cuenta las necesidades psicológicas existentes a nivel individual y colectivo y las posibilidades de intervenir en cada periodo de preparación. El trabajo psicológico ha sido realizado utilizando la vía directa entre psicólogos y deportistas y empleando la vía indirecta mediante las decisiones y actuaciones del entrenador principal, de los restantes miembros del cuadro técnico y, en ocasiones, de algunas jugadoras más veteranas como intermediarios. Los servicios prestados han sido de diversa índole, abarcando los dos grandes núcleos de trabajo en el deporte de competición: el entrenamiento y la propia competición, debiendo considerarse bastante positiva la valoración de los mismos al haberse estimado que lintervenciónpsicológica ha favorecido una notable mejora en el funcionamiento psicológico del equipo y ha contribuído al éxito deportivo individual y colectivo. Las principales dificultades encontradas y los puntos positivos del ptograma de intervención empleado, conducen a interesantes sugerencias y conclusiones que pueden ser de gran utilidad a las futuras aplicaciones de la ciencia psicológica para la mejora del rendimiento deportivo, sobre todo en las especialidades de equipoSpain's Olympic National Women's Field Hockey Team has carried our an inrensive and comprehensive training programme with the aim of preparing the Olympic Games of Barcelona. Within the various fields of this programme, psychological intervenrion has taken up an outstanding place with one sport psychologist, the first author, being a permanent member of the staff under the global responsability of the head coach and other sport psychologist, the second author, working as active advicer. Psychological intervention has been all the time well coordinated with the athletic training programme, considering individual and group psychological needs and the priority and feasibility of psychological work in each training period. Likewise, psychological work has been carried out both through a direct channel beetween psychologists and athletes and through an indirect channel using coaches, other members of the staff and even some of rhe oldest players as active mediators. Different kind of psychological services have been provided, covering the two main areas of work in competitive sport: training and competition. In general terms, psychological work should be considered highly positive, due to its observed contribution to a considerable improvement of psychological functioning and, further, to individual and group athletic success. Both the main difficulties and the positive aspects of the programme utilized lead to interesting suggestions and conclusions for rhe application of psychological science to the field of sport performance in the future, especially concerning team sport

Comprehensive study of phase transitions in relaxational systems with field-dependent coefficients

We present a comprehensive study of phase transitions in single-field systems that relax to a non-equilibrium global steady state. The mechanism we focus on is not the so-called Stratonovich drift combined with collective effects, but is instead similar to the one associated with noise-induced transitions a la Horsthemke-Lefever in zero-dimensional systems. As a consequence, the noise interpretation (e.g., Ito vs Stratonvich) merely shifts the phase boundaries. With the help of a mean-field approximation, we present a broad qualitative picture of the various phase diagrams that can be found in these systems. To complement the theoretical analysis we present numerical simulations that confirm the findings of the mean-field theory

KPZ models: Height gradient fluctuations and the tilt method

When an interface model belonging to the KPZ universality class is tilted with average slope m, its average velocity increases in Λ/2 m2. The coefficient Λ can only be related to the non-linear coefficient λ from the KPZ equation if the mean square of the height gradient also increases in bm2 when the interface is tilted. For the continuous KPZ equation, b = 1 and the relation Λ = λ is achieved. In this work, we study the local fluctuations of the height gradient through an analysis of the values of b. We show that, for one-dimensional discrete KPZ models, 1-b ∼ sγb, where s is the discretization step chosen to calculate the height gradient. The exponent γb that we measure matches the power-law exponent associated with the finite-size corrections of the interface average velocity, i.e. γb = 2(ζ- 1), where ζ is the global roughness exponent. Lastly, we show how, for restricted (unrestricted) growth models, the value of b goes to 1 from below (above) as s increases.Fil: Torres, M. F.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Física; ArgentinaFil: Buceta, Ruben Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Física; Argentin

Development of a child with Joubert syndrome.

Sin resume

Situaciones estresantes y vulnerabilidad a las lesiones deportivas : un estudio con deportistas de equipo

El objetivo de este estudio es analizar la influencia de sucesos vitales y circunstancias deportivas estresantes en el riesgo de lesiones de deportistas practicantes de deportes colectivos con oposición directa. Ciento sesenta y ocho deportistas participaron en la investigación. Al comienzo de la temporada deportiva los sujetos cumplimentaron un cuestionario de sucesos vitales y un informe de lesiones sufridas durante la última temporada deportiva. Posteriormente, a lo largo de todo el período de competición se recogió información sobre la presencia de diversas circunstancias deportivas potencialmente estresantes y se registraron las lesiones padecidas por los sujetos participantes. Los resultados indican la influencia de acontecimientos vitales y circunstancias estresantes deportivas en el aumento de la vulnerabilidad a las lesiones, especialmente cuando ambas variables son medidas en relación al mismo período temporal.The aim of this study is to analyse the effects of life events and stressful sport situations on the risk of sport injuries in athletes practising team sports against other teams. One hundred and sixty-eight athletes took part in the investigation. The subjects completed a questionnaire on life events and a report on injuries sustained during the previous sport season at the beginning of the sports season. Subsequently, information on potentially stressful sport situations and injuries sustained by the participants was gathered throughout the entire competition period. Results indicate the effects of life events and stressful sport situations on increased vulnerability to injuries, especially when both variables are related to the same temporary period

Microemulsions as Nanoreactors to Obtain Bimetallic Nanoparticles

Microemulsions are frequently used as nanoreactors for the synthesis of bimetallic nanoparticles. The ability to manipulate the metal distribution in bimetallic nanoparticles is essential for optimizing applications, and it requires a deeper understanding of how compartmentalization of reaction medium affects nanoparticle synthesis. A simulation model was developed to predict the atomic structure of bimetallic nanoparticles prepared via microemulsion in terms of metals employed and microemulsion composition. The model was successfully proved by comparing theoretical and experimental Au/Pt STEM profiles. On this basis, the model becomes a strong tool to further enhance our knowledge of the complex mechanisms governing reactions in microemulsions and its impact on final nanostructures. The purpose of this study is to perform a comprehensive kinetic analysis of coreduction of different couple of metals in the light of the interplay between three kinetic parameters: intermicellar exchange rate, chemical reduction rates of the two metals, and reactants concentration. The particular combination of these factors determines the reaction rate of each metal, which in turn determines the final metal arrangement

Beneficios percibidos de las lesiones deportivas : estudio cualitativo en futbolistas profesionales y semiprofesionales

El objetivo del estudio fue identificar y analizar los beneficios percibidos asociados a la lesión deportiva, en 16 futbolistas profesionales y semiprofesionales que se habían lesionado durante su práctica deportiva. Para la recogida de datos se realizaron entrevistas semiestructuradas, siendo el análisis de contenido efectuado través del software QSR Nvivo 2.0. Los participantes reportaron 31 beneficios percibidos en todo su proceso de lesión, siendo el apoyo social y la educación deportiva los más referidos. Las conclusiones apuntan para la importancia de incluir aspectos positivos para una comprensión más clara y completa del impacto global de las lesiones deportivas.The aim of the study was to identify and analyze the perceived benefits associated with sports injury in 16 professional and semi-professional players who were injured during sports practice. For data collection semi-structured interviews were conducted, content analyses being performed through the QSR Nvivo 2.0 software. 31 participants reported perceived benefits throughout the injury process, with social support and sports education referrals. The findings point to the importance of including positive aspects for a clearer and more complete understanding of the overall impact of sports injuries.O objectivo do estudo foi identificar e analisar os benefícios percebidos associados à lesão desportiva em 16 jogadores profissionais e semiprofissionais que se lesionaram durante a prática desportiva. Para a recolha de dados foram realizadas entrevistas semi-estruturadas, sendo a análise de conteúdo efectuada através do software QSR Nvivo 2.0. Os participantes reportaram 31 benefícios percebidos durante todo o processo de lesão, sendo o suporte social e a educação desportiva os mais referidos. As conclusões apontam para a importância de incluir aspectos positivos para uma compreensão mais clara e mais completa do impacto global das lesões desportivas