3,142 research outputs found
Effects of Motivation, Basic Psychological Needs, and Teaching Competence on Disruptive Behaviours in Secondary School Physical Education Students
Currently, disruptive and aggressive behaviours of a physical and verbal nature are a reality among adolescent students and a concern in the educational context. Therefore, the main objective of this research was to analyse the effects of perceived teaching competence, motivation and basic psychological needs on disruptive behaviours in secondary school PE students. The sample was composed of 758 adolescent students from seven public secondary schools. The following instruments adapted to physical education were used: The Disruptive Behaviours Questionnaire, The Evaluation of Teaching Competencies Scale, The Sport Motivation Scale, and The Basic Psychological Needs Scale. Multilevel regression models with the MIXED procedure were performed for data analysis. The results show that misbehaviour is more likely among male students and that disruptive behaviours decrease when a teacher is perceived as competent. Students with greater self-determined motivation are more likely to exhibit fewer behaviours related to low engagement and irresponsibility while amotivation increases the different disruptive behaviours in the classroom. In conclusion, it is proposed that educators work in line with the students’ needs by responding to their interests and that this will increase self-determined motivation
Transformation of anthropological status in elderly with type II diabetes through exercise: pilates and aerobic exercise
Las estadísticas muestran que 285 millones de personas sufren de Diabetes Tipo II, esto es el 6% de la población mundial adulta y 60 millones de personas en los Estados Unidos (10% de la población). De los 47 millones de habitantes que posee España, mas de 3 millones de personas sufren de diabetes (6.4%). En el año 2010 se gastaron más de 106 mil millones de dólares en salud por causa de la diabetes en los Estados Unidos. El ejercicio físico es una manera de evitar la diabetes en la población a través de: un mejor uso de la propia insulina producida por el cuerpo, de la quema de grasas, del control del peso corporal, del aumento de la fuerza muscular y del aumento en la densidad y calidad ósea. Una frecuencia semanal de 250 a 300 minutos de actividad física puede resultar de gran ayuda en el control de esta patología. La práctica de Pilates es un ejercicio que puede ser utilizado para lograr fácilmente un estado físico saludable. Puede ser realizado en el hogar, aprendiendo la técnica a través de la TV o de DVDs, es conveniente y sin costos. Además no presenta riesgos para las personas con diabetes tipo II, quienes son vulnerables por presentar una biomecánica disminuida en los miembros inferiores y/o una disfunción de la marcha
Steady self-diffusion in classical gases
A steady self-diffusion process in a gas of hard spheres at equilibrium is
analyzed. The system exhibits a constant gradient of labeled particles. Neither
the concentration of these particles nor its gradient are assumed to be small.
It is shown that the Boltzmann-Enskog kinetic equation has an exact solution
describing the state. The hydrodynamic transport equation for the density of
labeled particles is derived, with an explicit expression for the involved
self-diffusion transport coefficient. Also an approximated expression for the
one-particle distribution function is obtained. The system does not exhibit any
kind of rheological effects. The theoretical predictions are compared with
numerical simulations using the direct simulation Monte Carlo method and a
quite good agreement is found
Anomalous self-diffusion in a freely evolving granular gas near the shearing instability
The self-diffusion coefficient of a granular gas in the homogeneous cooling
state is analyzed near the shearing instability. Using mode-coupling theory, it
is shown that the coefficient diverges logarithmically as the instability is
approached, due to the coupling of the diffusion process with the shear modes.
The divergent behavior, which is peculiar of granular gases and disappears in
the elastic limit, does not depend on any other transport coefficient. The
theoretical prediction is confirmed by molecular dynamics simulation results
for two-dimensional systems
Uniform self-diffusion in a granular gas
A granular gas composed of inelastic hard spheres or disks in the homogeneous
cooling state is considered. Some of the particles are labeled and their number
density exhibits a time-independent linear profile along a given direction. As
a consequence, there is a uniform flux of labeled particles in that direction.
It is shown that the inelastic Boltzmann-Enskog kinetic equation has a solution
describing this self-diffusion state. Approximate expressions for the transport
equation and the distribution function of labeled particles are derived. The
theoretical predictions are compared with simulation results obtained using the
direct Monte Carlo method to generate solutions of the kinetic equation. A
fairly good agreement is found
The shearing instability of a dilute granular mixture
The shearing instability of a dilute granular mixture composed of smooth
inelastic hard spheres or disks is investigated. By using the Navier-Stokes
hydrodynamic equations, it is shown that the scaled transversal velocity mode
exhibits a divergent behaviour, similarly to what happens in one-component
systems. The theoretical prediction for the critical size is compared with
direct Monte Carlo simulations of the Boltzmann equations describing the
system, and a good agreement is found. The total energy fluctuations in the
vicinity of the transition are shown to scale with the second moment of the
distribution. The scaling distribution function is the same as found in other
equilibrium and non-equilibrium phase transitions, suggesting the existence of
some kind of universality
Vibrated granular gas confined by a piston
The steady state of a vibrated granular gas confined by a movable piston on
the top is discussed. Particular attention is given to the hydrodynamic
boundary conditions to be used when solving the inelastic Navier-Stokes
equations. The relevance of an exact general condition relating the grain
fluxes approaching and moving away from each of the walls is emphasized. It is
shown how it can be used to get a consistent hydrodynamic description of the
boundaries. The obtained expressions for the fields do not contain any
undetermined parameter. Comparison of the theoretical predictions with
molecular dynamics simulation results is carried out, and a good agreement is
observed for low density and not too large inelasticity. A practical way of
introducing small finite density corrections to the dilute limit theory is
proposed, to improve the accuracy of the theory
Power-law decay of the velocity autocorrelation function of a granular fluid in the homogeneous cooling state
The hydrodynamic part of the velocity autocorrelation function of a granular
fluid in the homogeneous cooling state has been calculated by using
mode-coupling theory for a finite system with periodic boundary conditions. The
existence of the shearing instability, leading to a divergent behavior of the
velocity flow fluctuations, is taken into account. A time region in which the
velocity autocorrelation function exhibits a power law decay, when time is
measured by the number of collisions per particle, has been been identified.
Also the explicit form of the exponential asymptotic long time decay has been
obtained. The theoretical prediction for the power law decay is compared with
molecular dynamics simulation results, and a good agreement is found, after
taking into account finite size corrections. The effects of approaching the
shearing instability are also explored
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