Vlasov simulations of Kinetic Alfv\'en Waves at proton kinetic scales

Kinetic Alfv\'en waves represent an important subject in space plasma physics, since they are thought to play a crucial role in the development of the turbulent energy cascade in the solar wind plasma at short wavelengths (of the order of the proton inertial length $d_p$ and beyond). A full understanding of the physical mechanisms which govern the kinetic plasma dynamics at these scales can provide important clues on the problem of the turbulent dissipation and heating in collisionless systems. In this paper, hybrid Vlasov-Maxwell simulations are employed to analyze in detail the features of the kinetic Alfv\'en waves at proton kinetic scales, in typical conditions of the solar wind environment. In particular, linear and nonlinear regimes of propagation of these fluctuations have been investigated in a single-wave situation, focusing on the physical processes of collisionless Landau damping and wave-particle resonant interaction. Interestingly, since for wavelengths close to $d_p$ and proton plasma beta $\beta$ of order unity the kinetic Alfv\'en waves have small phase speed compared to the proton thermal velocity, wave-particle interaction processes produce significant deformations in the core of the particle velocity distribution, appearing as phase space vortices and resulting in flat-top velocity profiles. Moreover, as the Eulerian hybrid Vlasov-Maxwell algorithm allows for a clean almost noise-free description of the velocity space, three-dimensional plots of the proton velocity distribution help to emphasize how the plasma departs from the Maxwellian configuration of thermodynamic equilibrium due to nonlinear kinetic effects

The perception of the poetic process to Greek and French writers, a basic lever of launching creative writing in education

"Poetry is the expression of the beautiful, through words elaborately woven with each other", according to the Argentine writer Borges Jorge-Luis. Poetic process, the complicated art of creating poetry becomes perceived in different ways by every author. Thus, for others, it consists a sacramental route where the creator-poet exposes his internal world, his thoughts, his personal experiences, through verses, being in a situation of daydreaming or vision. Certainly, this clearly individual element in poetry is inevitably influenced from external factors, such as the common ideology of the times, the socio-political status and the moral perception of society. This emotive experience is especially arduous and suppressive and for the person who tastes it. However, this traumatic experience is simultaneously a curative treatment for the poet. For most poets, writhing poems reflects a situation of liberty, autonomy, promotion of ego and personal feelings, which are suppressed by the conservative look of the society whereas they, finally, find outlet through creation. French Surrealists move towards this spirit, and, generally, creators. For the beginning of this ceremony of poetic action, the boost, the stimulus, the spark that will penetrate the spirit of the poet enabling him to create poetry are necessary. And surely, the conception of many poems takes place during the evolution of a dream, where the poet’s spirit is free to express as it wishes itself. A basic resource of inspiration for the majority of poets is the past, pleasant or traumatic, a stone corner of the past, however, and a guide towards the uncertain future. The concept of "Creative Writing" is placed on the same wavelength with the poetic process. In reality, it is integrated into it. All these who adopt and get involved with creative writing, are possessed with the same feelings and worries. The pleasure of creation, the new. The individual expression, the mental amalgamation with the receiver-reader are diffused. Furthermore, the person discovers new, until then, possibilities of himself. In parallel, there is an extroversion in the whole procedure. Positive experience creates the will for further continuation of this attempt. Regarding the cultivation and promotion of the trainees’ abilities of creative writing, the role of the teacher is extremely important. The analyses of the texts of respected creators from the teacher function in a helpful way , as well as the perceptions related to writing of the writers themselves. What is more, this is intensified when common points of writers’ assembly (Greeks and foreigners) about poetic creation are located. Teachers should present the positive elements of creative writing if they wish to reach its desired result and cultivation. After all this analysis and contact of trainees with the thoughts and way of writing of known writers, the need and desire for an attempt of trying this experience will, gradually, take place. This attempt of trial functions as a basic lever for the launch of creative writing. Besides, "writing is nothing else but a guided dream" (Borges Jorge- Luis). A "dream" that we all of us should live

Cepstral analysis based on the Glimpse proportion measure for improving the intelligibility of HMM-based synthetic speech in noise

In this paper we introduce a new cepstral coefficient extraction method based on an intelligibility measure for speech in noise, the Glimpse Proportion measure. This new method aims to increase the intelligibility of speech in noise by modifying the clean speech, and has applications in scenarios such as public announcement and car navigation systems. We first explain how the Glimpse Proportion measure operates and further show how we approximated it to integrate it into an existing spectral envelope parameter extraction method commonly used in the HMM-based speech synthesis framework. We then demonstrate how this new method changes the modelled spectrum according to the characteristics of the noise and show results for a listening test with vocoded and HMM-based synthetic speech. The test indicates that the proposed method can significantly improve intelligibility of synthetic speech in speech shaped noise. Index Terms — cepstral coefficient extraction, objective measure for speech intelligibility, Lombard speech, HMM-based speech synthesis 1

POSTURAL CONTROL IN CHILDREN BORN AT TERM ACCORDING TO THE ALBERTA INFANT MOTOR SCALE: COMPARISON BETWEEN SEXES

Introduction: acquisitions and changes in the motor and cognitive development of boys and girls are related not only to existing biological differences between both sexes, but also to socio-economic, cultural and family factors. Objective: to investigate the differences between sexes in the acquisition of anti-gravitational postures. Methods: the participants in this study were 638 children born at term (324 males and 314 females), from 0 to 18 months, coming from Infant Education Schools in the south of Brazil. The Alberta Infant Motor Scale (AIMS) was used to evaluate motor performance. Results: most of the evaluated children showed normal motor performance for their age (69.7%), with nonlinear development and plateaus in postural acquisition from 15 months. There were not significant differences (p>0.05) in motor performance between boys and girls from 0 to 18 months. Conclusion: motor development was similar between the sexes in the first months of life. However, throughout childhood, sociocultural differences and parents’ practices seem to influence differently the process of motor acquisition and development of skills, since children are exposed to experiences in conformity with sex expectations

General Recursion and Formal Topology.

Comment: In Proceedings PAR 2010, arXiv:1012.455