Microscopic description for the emergence of collective dissipation in extended quantum systems

Practical implementations of quantum technology are limited by unavoidable effects of decoherence and dissipation. With achieved experimental control for individual atoms and photons, more complex platforms composed by several units can be assembled enabling distinctive forms of dissipation and decoherence, in independent heat baths or collectively into a common bath, with dramatic consequences for the preservation of quantum coherence. The cross-over between these two regimes has been widely attributed in the literature to the system units being farther apart than the bath's correlation length. Starting from a microscopic model of a structured environment (a crystal) sensed by two bosonic probes, here we show the failure of such conceptual relation, and identify the exact physical mechanism underlying this cross-over, displaying a sharp contrast between dephasing and dissipative baths. Depending on the frequency of the system and, crucially, on its orientation with respect to the crystal axes, collective dissipation becomes possible for very large distances between probes, opening new avenues to deal with decoherence in phononic baths

Avaliação dos Fatores Influentes na Vulnerabilidade à Erosão do Solo por Meio de Decisão Multicritério e de Técnicas de Geoprocessamento no Município de Piratini – RSV

The land degradation is the loss of their natural , physical and biochemical qualities , caused mostly by erosion , which leads into a socioeconomic and environmental problem. The objective was to assess the vulnerability of soil erosion in Piratini-RS, according to some potentially influence environmental characteristics of this occurrence anthropogenic. For this environmental assessment we used maps of the following themes: land use, soil science, geology and slope. According to the methodology proposed by Xavier-da-Silva (2001), which considers the multicriteria analysis, the scores were assigned from 1 (very low vulnerability) to 10 (highest vulnerability) to the constituent classes of these maps. The results showed that the use of classes " above ground " and " field " are the most vulnerable to erosion, as well as the slopes of class " 12-20 %" and " 5-12 %". The areas with high vulnerability of erosion represent 72,07 % of the Piratini municipal area, while 26,71 % represent areas of highest vulnerability of erosion and 1,22 % median vulnerability of soil loss.O objetivo foi avaliar o risco de erosão do solo no município de Piratini-RS, segundo algumas características ambientais potencialmente influenciadoras dessa ocorrência antrópica. Para essa avaliação ambiental utilizou-se mapas dos seguintes temas: uso do solo, pedologia, declividade e geologia.  Segundo a metodologia proposta por Xavier-da-Silva (2001), a qual considera a análise multicritério, foram atribuídas as notas de 1 (baixíssimo risco) a 10 (altíssimo risco) às classes constituintes desses mapas. Os resultados evidenciaram que as classes de uso “solo exposto” e o “campo” são as mais vulneráveis à erosão, assim como as classes de declividades de “12 a 20%” e “5 a 12%”. As áreas com alto risco de erosão representam 72,07% da área do município de Piratini, enquanto que 26,71% representam áreas de altíssimo risco de erosão e com 1,22% possui risco de perdas de solo medianas

An Overview of the Main Genetic, Epigenetic and Environmental Factors Involved in Autism Spectrum Disorder Focusing on Synaptic Activity

Autism spectrum disorder (ASD) is a neurodevelopmental disorder that aects social interaction and communication, with restricted interests, activity and behaviors. ASD is highly familial, indicating that genetic background strongly contributes to the development of this condition. However, only a fraction of the total number of genes thought to be associated with the condition have been discovered. Moreover, other factors may play an important role in ASD onset. In fact, it has been shown that parental conditions and in utero and perinatal factors may contribute to ASD etiology. More recently, epigenetic changes, including DNA methylation and micro RNA alterations, have been associated with ASD and proposed as potential biomarkers. This review aims to provide a summary of the literature regarding ASD candidate genes, mainly focusing on synapse formation and functionality and relevant epigenetic and environmental aspects acting in concert to determine ASD onset