Velocity Statistics in the Two-Dimensional Granular Turbulence

We studied the macroscopic statistical properties on the freely evolving quasi-elastic hard disk (granular) system by performing a large-scale (up to a few million particles) event-driven molecular dynamics systematically and found that remarkably analogous to an enstrophy cascade process in the decaying two-dimensional fluid turbulence. There are four typical stages in the freely evolving inelastic hard disk system, which are homogeneous, shearing (vortex), clustering and final state. In the shearing stage, the self-organized macroscopic coherent vortices become dominant. In the clustering stage, the energy spectra are close to the expectation of Kraichnan-Batchelor theory and the squared two-particle separation strictly obeys Richardson law.Comment: 4 pages, 4 figures, to be published in PR

Earliest Pragian (Early Devonian) corals and stromatoporoids from reefal settings in the Cantabrian Zone (N Spain)

The oldest reefal episode in the Cantabrian Zone (earliest Pragian) consists of small biostromal patch reefs, mainly built by corals and stromatoporoids, and developed on a storm-dominated ramp. Four outcrops provide the stratigraphic framework in which these reef facies developed, and these permitted an interpretation of their depositional setting in terms of a relatively distal or protected shelf. We systematically describe three species of rugose corals, five species of tabulate corals, and six species of stromatoporoids. This fauna is allocated to three Pragian fossil associations. Association 1 is mainly composed of massive tabulate corals and stromatoporoids. Association 2 contains dominant branching rugose and tabulate corals. Finally, association 3 is represented by tiny massive tabulate corals. Each association occurs at a specific location within a framework of high-frequency deepening upward cycles, being related to a specific depositional setting. This mode of occurrence suggests that their development was tuned by relative base-level oscillations, forming during rises that took the sea-bottom to relatively deep or sheltered conditions, with rare reworking by storm-related currents. Finally, a comparison of this reefal fauna with examples of similar age from elsewhere is presented in order to explore their affinities

Desarrollo de un sistema fotogramétrico tridimensional computerizado no invasivo para el análisis de la columna vertebral humana

El presente trabajo expone el desarrollo de un sistema fotogramétri- co tridimensional (3D) no invasivo basado en la utilización de imágenes radiológicas que permite el análisis de la columna vertebral humana para su aplicación en el ámbito de la investigctción básica acerca del comportamiento de la columna y su utilización práctica para facilitar el diagnóstico clínico en los centros médi- -cos. A pártir de Ia información obtenida mediante imágenes radio- tógicai son aplicadas técnicas fotogramétricas 3D computerizadas que permiten con una adecuada metodología no invasiva la obtención de diversos parámetros biomectínicos que permiten detetminar el comportamiento estático y dinámico de la columna. Asimismo se desarrollan ciertos algoritmos de representación gráfica tri- dimensional de la columna vertebral humana que la simulan de forma realista; esto puede suponer un avance importante para su utilización en el perfeccionamiento del diagnóstico clínico. El sistema desarrollado ha sido aplicado de forma práctica sobre una muestra de pacientes afectados por diversos grados de escoliosis.Peer Reviewe

Velocity Fluctuations in Electrostatically Driven Granular Media

We study experimentally the particle velocity fluctuations in an electrostatically driven dilute granular gas. The experimentally obtained velocity distribution functions have strong deviations from Maxwellian form in a wide range of parameters. We have found that the tails of the distribution functions are consistent with a stretched exponential law with typical exponents of the order 3/2. Molecular dynamic simulations shows qualitative agreement with experimental data. Our results suggest that this non-Gaussian behavior is typical for most inelastic gases with both short and long range interactions.Comment: 4 pages, 4 figure

Gravitational Wave Spectrum in Inflation with Nonclassical States

The initial quantum state during inflation may evolve to a highly squeezed quantum state due to the amplification of the time-dependent parameter, $\omega_{phys}(k/a)$, which may be the modified dispersion relation in trans-Planckian physics. This squeezed quantum state is a nonclassical state that has no counterpart in the classical theory. We have considered the nonclassical states such as squeezed, squeezed coherent, and squeezed thermal states, and calculated the power spectrum of the gravitational wave perturbation when the mode leaves the horizon.Comment: 21 page

Tensorpac: An open-source Python toolbox for tensor-based phase-amplitude coupling measurement in electrophysiological brain signals

Despite being the focus of a thriving field of research, the biological mechanisms that underlie information integration in the brain are not yet fully understood. A theory that has gained a lot of traction in recent years suggests that multi-scale integration is regulated by a hierarchy of mutually interacting neural oscillations. In particular, there is accumulating evidence that phase-amplitude coupling (PAC), a specific form of cross-frequency interaction, plays a key role in numerous cognitive processes. Current research in the field is not only hampered by the absence of a gold standard for PAC analysis, but also by the computational costs of running exhaustive computations on large and high-dimensional electrophysiological brain signals. In addition, various signal properties and analyses parameters can lead to spurious PAC. Here, we present Tensorpac, an open-source Python toolbox dedicated to PAC analysis of neurophysiological data. The advantages of Tensorpac include (1) higher computational efficiency thanks to software design that combines tensor computations and parallel computing, (2) the implementation of all most widely used PAC methods in one package, (3) the statistical analysis of PAC measures, and (4) extended PAC visualization capabilities. Tensorpac is distributed under a BSD-3-Clause license and can be launched on any operating system (Linux, OSX and Windows). It can be installed directly via pip or downloaded from Github (https://github.com/EtienneCmb/tensorpac). By making Tensorpac available, we aim to enhance the reproducibility and quality of PAC research, and provide open tools that will accelerate future method development in neuroscience

Bifurcations of a driven granular system under gravity

Molecular dynamics study on the granular bifurcation in a simple model is presented. The model consists of hard disks, which undergo inelastic collisions; the system is under the uniform external gravity and is driven by the heat bath. The competition between the two effects, namely, the gravitational force and the heat bath, is carefully studied. We found that the system shows three phases, namely, the condensed phase, locally fluidized phase, and granular turbulent phase, upon increasing the external control parameter. We conclude that the transition from the condensed phase to the locally fluidized phase is distinguished by the existence of fluidized holes, and the transition from the locally fluidized phase to the granular turbulent phase is understood by the destabilization transition of the fluidized holes due to mutual interference.Comment: 35 pages, 17 figures, to be published in PR

Retrospective study of pre-anesthetic electrocardiogram examination of 700 dogs conducted at the Veterinary Hospital of UFMG (2013-2014)

Abstract: Pre-operative electrocardiograms performed in 700 dogs were analyzed in order to establish correlation between sex, age, indication for surgery, body condition score, breed and weight. Initially a clinical questionnaire was filled out from each owner, including age, breed, sex, weight, clinical history and surgical indication. Dogs above 6 years of age or those showing any kind of cardiac auscultation disturbances were referred to electrocardiogram (ECG) evaluation. All ECG were performed and analyzed by the same veterinary specialist. Abnormalities at ECG were founnd in 364 of 700 (52%) evaluated dogs, and the most frequent variation was sinus arrhythmia, observed in 293 dogs (25.4%). No significant correlation was found between the electrocardiographic alterations with weight, sex and age of the animals. Therefore ECG should be conducted routinely regardless of age, sex, breed or surgical indication, highlighting its value for determining a safe anesthetic protocol that promotes minimal cardiopulmonary depression and allows rapid post-surgical recovery

The Psychological Science Accelerator’s COVID-19 rapid-response dataset

In response to the COVID-19 pandemic, the Psychological Science Accelerator coordinated three large-scale psychological studies to examine the effects of loss-gain framing, cognitive reappraisals, and autonomy framing manipulations on behavioral intentions and affective measures. The data collected (April to October 2020) included specific measures for each experimental study, a general questionnaire examining health prevention behaviors and COVID-19 experience, geographical and cultural context characterization, and demographic information for each participant. Each participant started the study with the same general questions and then was randomized to complete either one longer experiment or two shorter experiments. Data were provided by 73,223 participants with varying completion rates. Participants completed the survey from 111 geopolitical regions in 44 unique languages/dialects. The anonymized dataset described here is provided in both raw and processed formats to facilitate re-use and further analyses. The dataset offers secondary analytic opportunities to explore coping, framing, and self-determination across a diverse, global sample obtained at the onset of the COVID-19 pandemic, which can be merged with other time-sampled or geographic data