8,980 research outputs found
Ergodic Transport Theory, periodic maximizing probabilities and the twist condition
The present paper is a follow up of another one by A. O. Lopes, E. Oliveira
and P. Thieullen which analyze ergodic transport problems. Our main focus will
a more precise analysis of case where the maximizing probability is unique and
is also a periodic orbit.
Consider the shift T acting on the Bernoulli space \Sigma={1, 2, 3,..,
d}^\mathbb{N} A:\Sigma \to \mathbb{R} a Holder potential.
Denote m(A)=max_{\nu is an invariant probability for T} \int A(x) \; d\nu(x)
and, \mu_{\infty,A}, any probability which attains the maximum value. We assume
this probability is unique (a generic property). We denote \T the bilateral
shift. For a given potential Holder A:\Sigma \to \mathbb{R}, we say that a
Holder continuous function W: \hat{\Sigma} \to \mathbb{R} is a involution
kernel for A, if there is a Holder function A^*:\Sigma \to \mathbb{R}, such
that, A^*(w)= A\circ \T^{-1}(w,x)+ W \circ \T^{-1}(w,x) - W(w,x). We say that
A^* is a dual potential of A. It is true that m(A)=m(A^*). We denote by V the
calibrated subaction for A, and, V^* the one for A^*. We denote by I^* the
deviation function for the family of Gibbs states for \beta A, when \beta \to
\infty.
For each x we get one (more than one) w_x such attains the supremum above.
That is, solutions of V(x) = W(w_x,x) - V^* (w_x)- I^*(w_x).
A pair of the form (x,w_x) is called an optimal pair. If \T is the shift
acting on (x,w) \in {1, 2, 3,.., d}^\mathbb{Z}, then, the image by \T^{-1} of
an optimal pair is also an optimal pair.
Theorem - Generically, in the set of Holder potentials A that satisfy
(i) the twist condition,
(ii) uniqueness of maximizing probability which is supported in a periodic
orbit, the set of possible optimal w_x, when x covers the all range of possible
elements x in \in \Sigma, is finite
Regulation of Marginal Zone B-Cell Differentiation by MicroRNA-146a.
B-cell development in the bone marrow is followed by specification into functional subsets in the spleen, including marginal zone (MZ) B-cells. MZ B-cells are classically characterized by T-independent antigenic responses and require the elaboration of distinct gene expression programs for development. Given their role in gene regulation, it is not surprising that microRNAs are important factors in B-cell development. Recent work demonstrated that deficiency of the NFκB feedback regulator, miR-146a, led to a range of hematopoietic phenotypes, but B-cell phenotypes have not been extensively characterized. Here, we found that miR-146a-deficient mice demonstrate a reduction in MZ B-cells, likely from a developmental block. Utilizing high-throughput sequencing and comparative analysis of developmental stage-specific transcriptomes, we determined that MZ cell differentiation was impaired due to decreases in Notch2 signaling. Our studies reveal miR-146a-dependent B-cell phenotypes and highlight the complex role of miR-146a in the hematopoietic system
Decision making and skill development In youth football players
Este artículo presenta como se desarrolla la toma de decisiones y la habilidad técnica en jugadores con alto nivel de pericia desde los 6-7 a 13-14 años. El marco teórico está basado en la perspectiva de los sistemas dinámicos y la enseñanza comprensiva de los deportes. Se tomó como muestra a 57 jugadores del primer equipo de cada categoría de edad del Albacete Balompié: prebenjamín, benjamín, alevín e infantil. El instrumento usado fue la Herramienta de Evaluación del Rendimiento de Juego (HERJ), que mide la toma de decisiones y la ejecución, incluyendo el análisis ecológico atendiendo a principios tácticos (Bayer, 1992), comparando la situación en el juego con la decisión aplicada. Los resultados se basan en el análisis inferencial y correlacional. La evolución del rendimiento de juego se orienta desde el ataque hasta la defensa. Se han encontrado diferencias significativas en las variables entre las cuatro categorías de formación estudiadas, especialmente en el
principio táctico de progresar hacia la portería contraria y en el desmarque, así como en el marcaje y la ayuda en defensa.This paper presents how decision-making and skills are developed in high level of expertise players from 6-7 to 13-14 years. The framework is based on the dynamical systems and teaching games for understanding approaches. Participants were 57 first team players of each age (n = 13 to 16) of Albacete Balompié: U-8, U-10, U-12 and U-14. The Game Performance Assessment Tool (GPET) was the instrument used for assessment, which measures decision-making and execution from an ecological view in relation to tactical principles (Bayer, 1992), comparing the game situation with the decision applied. The results are based on inferential and correlation analysis. The evolution of knowledge evolves attack to defensive. We have found significant differences in variables between the four age categories studied. These differences have been shown in attack: the progress toward goal tactical principle and shake off; on defence: marking and cover (off-ball defenders)
Pulsar Prospects for the Cherenkov Telescope Array
In the last few years, the Fermi-LAT telescope has discovered over a 100
pulsars at energies above 100 MeV, increasing the number of known gamma-ray
pulsars by an order of magnitude. In parallel, imaging Cherenkov telescopes,
such as MAGIC and VERITAS, have detected for the first time VHE pulsed
gamma-rays from the Crab pulsar. Such detections have revealed that the Crab
VHE spectrum follows a power-law up to at least 400 GeV, challenging most
theoretical models, and opening wide possibilities of detecting more pulsars
from the ground with the future Cherenkov Telescope Array (CTA). In this
contribution, we study the capabilities of CTA for detecting Fermi pulsars. For
this, we extrapolate their spectra with "Crab-like" power-law tails in the VHE
range, as suggested by the latest MAGIC and VERITAS results.Comment: 4 pages, 3 figures. In Proceedings of the 2012 Heidelberg Symposium
on High Energy Gamma-Ray Astronomy. All CTA contributions at arXiv:1211.184
Perceptive training of youth volleyball blockers
Este estudio analiza la eficacia de un programa de entrenamiento
perceptivo basado en la orientación de la atención para la mejora de la toma de
decisiones y el rendimiento en la acción de bloqueo de voleibol. 16 jugadoras
juveniles fueron distribuidas en tres grupos: vídeo (n=6), que recibió ocho
sesiones de entrenamiento en vídeo; mixto (n=5), que recibió 4 sesiones en
vídeo y 4 sesiones de práctica en campo; y control (n=5), que completó las
pruebas de evaluación. Los resultados muestran cómo el programa de
entrenamiento mejoró la toma de decisiones de las jugadoras, ya que redujeron
su tiempo de reacción (F(1,13)=9,237, p=0,009, ηp
2=0,415) manteniendo el
mismo porcentaje de aciertos. Sin embargo, es necesaria la práctica en campo
para lograr transferir dichos aprendizajes al juego real, ya que sólo el grupo mixto
mejora el porcentaje de aciertos en el test de rendimiento en campo
(F(2,13)=8,608, p=0,004, ηp2=0,570; t(4) =-6,216, p=0,003)This study examines the effectiveness of a training program based on
perceptual orientation of attention for improving decision-making and
performance in the blocking action of volleyball. 16 youth players were divided
into three groups: video (n=6), which received eight perceptual training sessions
by video; mixed (n=5), which received only half of the sessions by video,
combined with practical training in the field; and control (n=5), which just
completed pre-test and post-test tests. Results show how orientation of
attention to relevant areas of information improved decision-making of the youth
volleyball players because they reduced their reaction time (F(1,13)=9,237,
p=0,009, ηp2=0,415) maintaining the same percentage of success. However,
the practice on the field is necessary to achieve transfer those learning to the
real game, because only mixed group improves the percentage of success in
the field performance test (F(2,13)=8,608, p=0,004, ηp2=0,570; t(4)=-6,216,
p=0,003
Interception of a corner kick in football: A task analysis
Debido a la inexistencia de estudios previos, la presente investigación tiene como objetivo realizar un análisis de la tarea, que es atrapar un balón procedente de un lanzamiento de córner. Para ello se analizó el rendimiento, el comportamiento motor y los movimientos oculares de jóvenes porteros cuando realizaban esta tarea. Además se compararon las variables en función de los aciertos o fallos durante el blocaje. Los resultados muestran que los fallos en el blocaje se deben a que los porteros iniciaron su carrera demasiado pronto y además utilizaron un patrón inadecuado del movimiento de sus manos y salto. El análisis de los movimientos oculares muestra que el balón es la zona informativa más importante, pero no se obtienen diferencias entre los aciertos y los fallos en el blocajeDue to the inexistence of previous studies, the present research is aimed at performing an analysis of the task of intercepting a ball coming from a corner kick. With that objective in mind, the motor behaviour and eye movements of young goalkeepers were analysed when performing the aforementioned task. Also, variables dependent on the number of right and wrong movements during the interception were compared. Results show that errors in blocking are due to the fact that goalkeepers began their run too early and also used an inadequate pattern of hand movement and jump. The analysis of eye movements shows that the ball is the most important informational zone, but no differences were found between hits and misses in the interception.La presente investigación se llevo a cabo mientras el primer autor disfrutaba de una beca FPU (Formación del Profesorado Universitario) otorgada por el Ministerio de Educación, Cultura y Deporte del Gobierno de Españ
The interception of a corner kick from the contraints-led perspective
El comportamiento motor surge de la continua interacción entre tres limitadores (organismo, entorno y tarea), que nunca actúan de forma aislada. Este artículo estudia su efecto en el rendimiento, comportamiento motor y comportamiento visual de porteros de fútbol durante el lanzamiento de córner. 31 participantes, divididos en tres grupos en función del nivel de juego, intentaron atrapar el balón procedente del lanzamiento de córner en dos situaciones (estática y dinámica), mientras que se registraron sus movimientos oculares. Entre los resultados se observa que los expertos tienen un rendimiento más estable, mientras que los otros grupos rinden peor en la situación más difícil; que los expertos realizan un inicio más tardío de la carrera hacia el balón y un patrón motor más rápido para atraparlo; y que la información contenida en los jugadores implicados no es relevante, ya que los porteros dedican valores cercanos al 0% del tiempo total a su fijaciónMotor behavior arises from the continuous interaction between three constraints (organism, environment and task), which never act in isolation. This paper studies the effect of the constraints on the performance, motor behavior and visual search behavior of soccer goalkeepers during the corner kick. 31 participants, divided into three groups depending on the level of play, tried to catch the ball out of a corner kick in two situations (static and dynamic), while their eye movements were recorded. Among the results it is observed that the experts have a more stable performance, while the other groups perform worse in the most difficult situation; that the experts make a later start of their run up towards the ball and a faster motor pattern to catch it; and that the that the information of the players involved is not relevant, goalkeepers dedicate values close to 0% of their visual total time to themLa presente investigación se llevó a cabo mientras el primer autor y la segunda autora disfrutaban de una beca FPU (Formación del Profesorado Universitario) otorgada por el Ministerio de Educación, Cultura y Deporte del Gobierno de España
Visual behavior influence on decision in volleyball blocking
El objetivo del presente estudio fue conocer la influencia del comportamiento visual (localización, número y duración de las fijaciones visuales) sobre la toma de decisiones en la acción del bloqueo en voleibol. Se analizó el comportamiento visual de 38 jugadoras de voleibol (23.9 4.2 años), que competían de manera federada, mediante el sistema de registro de movimientos oculares (Mobile Eye) durante la visualización de secuencias de video proyectadas a tamaño real. Los modelos de regresión obtenidos muestran que se obtienen mayores porcentajes de acierto cuando la duración de las fijaciones es reducida en las zonas HC y CB, y cuando aumenta el número de fijaciones en la zona BM y disminuye en la zona CBThe purpose of this study was to determine the influence of visual behaviour (visual fixation location, number and duration) on decision-making in volleyball blocking. The visual behavior of 38 volleyball players (23.9 4.2 years), who took part in federated competition, was analyzed with the eye tracking system (Mobile Eye) during visualization of real size video sequences. Regression models show that higher success percentages were obtained when the duration of fixations is low in HC and CB areas, and when the number of fixations increases in BM zone and decreases in CB zon
The Analyticity of a Generalized Ruelle's Operator
In this work we propose a generalization of the concept of Ruelle operator
for one dimensional lattices used in thermodynamic formalism and ergodic
optimization, which we call generalized Ruelle operator, that generalizes both
the Ruelle operator proposed in [BCLMS] and the Perron Frobenius operator
defined in [Bowen]. We suppose the alphabet is given by a compact metric space,
and consider a general a-priori measure to define the operator. We also
consider the case where the set of symbols that can follow a given symbol of
the alphabet depends on such symbol, which is an extension of the original
concept of transition matrices from the theory of subshifts of finite type. We
prove the analyticity of the Ruelle operator and present some examples
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