An extended admixture pulse model reveals the limitations to human-Neandertal introgression dating

Neandertal DNA makes up 2–3% of the genomes of all non-African individuals. The patterns of Neandertal ancestry in modern humans have been used to estimate that this is the result of gene flow that occurred during the expansion of modern humans into Eurasia, but the precise dates of this event remain largely unknown. Here, we introduce an extended admixture pulse model that allows joint estimation of the timing and duration of gene flow. This model leads to simple expressions for both the admixture segment distribution and the decay curve of ancestry linkage disequilibrium, and we show that these two statistics are closely related. In simulations, we find that estimates of the mean time of admixture are largely robust to details in gene flow models, but that the duration of the gene flow can only be recovered if gene flow is very recent and the exact recombination map is known. These results imply that gene flow from Neandertals into modern humans could have happened over hundreds of generations. Ancient genomes from the time around the admixture event are thus likely required to resolve the question when, where, and for how long humans and Neandertals interacted

Auditory environmental context affects visual distance perception

In this article, we show that visual distance perception (VDP) is influenced by the auditory environmental context through reverberation-related cues. We performed two VDP experiments in two dark rooms with extremely different reverberation times: an anechoic chamber and a reverberant room. Subjects assigned to the reverberant room perceived the targets farther than subjects assigned to the anechoic chamber. Also, we found a positive correlation between the maximum perceived distance and the auditorily perceived room size. We next performed a second experiment in which the same subjects of Experiment 1 were interchanged between rooms. We found that subjects preserved the responses from the previous experiment provided they were compatible with the present perception of the environment; if not, perceived distance was biased towards the auditorily perceived boundaries of the room. Results of both experiments show that the auditory environment can influence VDP, presumably through reverberation cues related to the perception of room size.Fil: Etchemendy, Pablo Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Acústica y Percepción Sonora; ArgentinaFil: Abregú, Ezequiel Lucas. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Acústica y Percepción Sonora; ArgentinaFil: Calcagno, Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Acústica y Percepción Sonora; ArgentinaFil: Eguia, Manuel Camilo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Acústica y Percepción Sonora; ArgentinaFil: Vechiatti, Nilda. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Acústica y Percepción Sonora; ArgentinaFil: Iasi, Federico. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Acústica y Percepción Sonora; ArgentinaFil: Vergara, Ramiro Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Acústica y Percepción Sonora; Argentin

Direito e emancipação humana

O artigo trata da relação entre o conceito de emancipa­ção humana e o Direito. Partindo do pressuposto que as formas jurídicas estão em profunda vinculação com as formas societárias das quais fazem parte, reflete-se sobre como o caráter estranhado das relações que cons­tituem a base da sociedade capitalista, determinam igualmente um estranhamento (alienação) no próprio Direito. Analisando o papel do Direito no processo e emancipação política, reflete-se sobre as condições de uma emancipação humana e as transformações que daí resultam sobre o fenômeno jurídico e o Estado

Tres originalidades y uno viejo camino

Análise da trajetória da Revolução Cubana tomando como hipótese três aspectos particulares que atribuem a esta experiência histórica sua originalidade e a reflexão sobre elementos de sua universalidade como manifestação histórica fundada na concepção socialista e nos pressupostos marxianos.Analysis of Cuban Revolution trajectory taking as hypothesis three particular aspects that attribute to this historical experience its originality and the reflection about elements of its universality as a historical manifestation which was established in the socialist conception and in the marxist presuppose.Análisis de una trayectoria de la Revolución Cubana,  tomando como hipótesis tres aspectos particulares que atribuyen a esta experiencia histórica, su originalidad y la reflexión  sobre elementos de suya universalidad como manifestación histórica fundada en  la concepción  socialista y en las propuestas  marxianos

O Marxismo diante de um novo século

A reestruturação produtiva do capital e a ofensiva ideológica contra o marxismo são analisadas como base para refletir sobre  a atualidade e validade das teses marxianas. O fundamento das afirmações sobre o fim do trabalho, da centralidade das classes sociais e da possibilidade de mudanças sociais na direção socialista, são analisadas à luz das determinações de uma contemporaneidade subssumida ao capital, que exige na perspectiva da analise a categoria da totalidade com suas implicações econômicas, políticas, sociais e ideológicas, no quadro de uma consciência social cética como expressão de um pensamento pós-moderno

Eflorescencia de ladrillos cerámicos comunes

En la superficie expuesta de ladrillos cerámicos comunes pueden aparecer luego de ciclos de mojado y secado, depósitos blanquecinos originados en la lixiviación de sales contenidas en los mismos. En este trabajo se informan experiencias realizadas para evaluar los condicionantes del proceso de lixiviación, en particular los vínculos con las características del material.White deposits due to the lixiviation of salts can appear at the exposed surface of ceramic bricks when they are submitted to several cycles of wetting and drying. This paper presents experiences realized to evaluate the characteristics and factors that affect this process

A educação física e o cuidado à saúde mental de adolescentes

As residências multiprofissionais em saúde têm como objetivo a formação qualificada dos profissionais voltados para as diretrizes do SUS. Diversos núcleos profissionais são aptos para tal formação. Entretanto, particularmente na área da Saúde Mental, o núcleo da Educação Física ainda busca um lugar e possui pouco espaço nos programas de residências vigentes. A atividade física tem seus benefícios comprovados na literatura, tanto em aspectos físicos, emocionais e sociais quanto para diferentes populações. A adolescência que compreende um período de mudanças também se beneficia com a prática. Ao ingressar, enquanto profissional de Educação Física, na Residência Multiprofissional em Saúde Mental Coletiva da Universidade Federal do Rio Grande do Sul, me deparei com diversos serviços que tinham os adolescentes como seu principal usuário. Durante minha prática, pude perceber o quanto as ferramentas da Educação Física podem ser importantes para o cuidado em saúde mental dessa população. Este trabalho traz alguns recortes de experiências vividas e uma reflexão teórica acerca do mesmo, para assim poder compreender o papel do profissional de Educação Física na área da saúde mental coletiva

Development of a computational tool to analyze sounds: A biological study with anuran

The emission of underwater sounds in anuran tadpoles has been documented in only two species from Argentina and one from Madagascar. Underwater sound emission by Ceratophrys ornata (Anura: Ceratophryidae) tadpoles was a novel finding reporting the first evidence in anuran larvae. The sound has been described as part of an antipredator mechanism that diminishes the frequency of predation between conspecifics. The aim of the study was to describe sound variability from tadpoles to adults with a novel technique in bioacoustics. Sounds emitted by tadpoles were both recorded underwater and out of water. The recording system consisted of a microphone and an interface coupled with a laptop. It was first calibrated with an acoustic reference source and compensated in order to obtain a recording system with flat frequency response. Audio recordings were digitalized, and post processed by a computational tool specifically developed in a numerical environment software. Variables selected to describe basic structure of sounds were: sound duration, number of pulses, number of inter pulses and dominant frequency. These variables were supplemented with typical acoustic parameters, such as equivalent continuous pressure level, peak sound pressure level, and spectral analysis with constant bandwidth filters. The interdisciplinary experience allowed developing a reliable system of recording, analysing thousand of sounds in a short period and therefore characterizing the sound of a species considering all variability

Auditory environmental context affects visual distance perception

To perceive the distance to an object through the visual modality, an observer uses a variety of cues, many of which may not be directly related to the target. This is illustrated by the fact that in a well-lit environment (with multiple visual cues) visual distance perception (VDP) is relatively accurate, whereas in a dark environment (where the observer can only see the target) VDP be- comes inaccurate. Besides, a number of recent studies indicate that VDP is not only affected by the availability and reliability of depth cues, but also can be influenced by the context even in the presence of multiple visual cues. Here we provide evidence that VDP is influenced by the auditory environmental context through reverberation-related cues. We conducted VDP experi- ments in two dark rooms with extremely different reverberation times: an anechoic chamber and a reverberant room. We first show that the distance to a visual object located in the reverberant chamber was perceived significantly farther than the same target located at the same distance in the anechoic chamber. The results also show that the maximum distance perceived by partic- ipants correlated significantly with the perceived size of the room. In addition, participants who performed the experiment in the reverberant room reported a perceived size greater than those who performed the experiment in the anechoic chamber although both rooms are of similar sizes. Secondly we note that by separating participants between musicians and non-musicians only the former group perceived differences in the size of the room through auditory modality; moreover, only this group perceived the distance to the visual object in the reverberant chamber farther than in the anechoic chamber. On the other hand, the group of non-musicians did not perceive dif- ferences in the size of both rooms or in the perceived distance in both chambers. These results show that the auditory environment can influence the VDP, presumably by reverberation cues related to auditory perception of the size of a room

Ventana temporal representativa para la medición del ruido urbano en la ciudad de La Plata

El objetivo de este trabajo es obtener una ventana temporal, a lo largo de un día típico en la ciudad, que sea representativa de parámetros diarios del ruido urbano (como por ejemplo el LDAY), dentro de un error conocido y aceptable. Para esto, primeramente se realiza un muestreo continuo, en campo, del ruido urbano durante 12 horas, sin interrupciones y en horario diurno; almacenándose en forma digital. Este procedimiento se repite en varias locaciones de la ciudad de La Plata, escogiéndose las mismas de modo que tengan, entre ellas, diferentes características de actividad urbana. De ese modo se consigue abarcar, en cierta forma, las diferentes condiciones de ruido que puedan encontrarse en la ciudad. Posteriormente se realiza un procesamiento en laboratorio de esos datos, analizándose exhaustivamente el comportamiento de diferentes parámetros acústicos, para intervalos de medición con diferentes duraciones temporales, y realizados en diferentes momentos del día. Asimismo, se comparan los resultados con los obtenidos en años anteriores en las mismas locaciones.This work attempts to know a temporal window, throughout a typical day in the city, which is representative of daily urban noise parameters (such as the Lday), within a known and acceptable deviation. To do this, a continuous on field sampling of the urban noise throughout 12 daytime hours and without interruption are carried out. Then is stored the data in a digital form. This procedure is repeated in several locations in the city of La Plata, picking them so that, between them, have different characteristics of urban activity. That can cover, in some way, the different conditions of noise that can be found in the city. Later a laboratory processing is performed, analyzing the behavior of different acoustic parameters for various intervals of measurement and with different durations of time, and performed at different times of the day. Also, the results are compared with those obtained in previous years at the same locations