Quantum networks reveal quantum nonlocality

The results of local measurements on some composite quantum systems cannot be reproduced classically. This impossibility, known as quantum nonlocality, represents a milestone in the foundations of quantum theory. Quantum nonlocality is also a valuable resource for information processing tasks, e.g. quantum communication, quantum key distribution, quantum state estimation, or randomness extraction. Still, deciding if a quantum state is nonlocal remains a challenging problem. Here we introduce a novel approach to this question: we study the nonlocal properties of quantum states when distributed and measured in networks. Using our framework, we show how any one-way entanglement distillable state leads to nonlocal correlations. Then, we prove that nonlocality is a non-additive resource, which can be activated. There exist states, local at the single-copy level, that become nonlocal when taking several copies of it. Our results imply that the nonlocality of quantum states strongly depends on the measurement context.Comment: 4 + 3 pages, 4 figure

Evolutionary plasticity determination by orthologous groups distribution

<p>Abstract</p> <p>Background</p> <p>Genetic plasticity may be understood as the ability of a functional gene network to tolerate alterations in its components or structure. Usually, the studies involving gene modifications in the course of the evolution are concerned to nucleotide sequence alterations in closely related species. However, the analysis of large scale data about the distribution of gene families in non-exclusively closely related species can provide insights on how plastic or how conserved a given gene family is. Here, we analyze the abundance and diversity of all Eukaryotic Clusters of Orthologous Groups (KOG) present in STRING database, resulting in a total of 4,850 KOGs. This dataset comprises 481,421 proteins distributed among 55 eukaryotes.</p> <p>Results</p> <p>We propose an index to evaluate the evolutionary plasticity and conservation of an orthologous group based on its abundance and diversity across eukaryotes. To further KOG plasticity analysis, we estimate the evolutionary distance average among all proteins which take part in the same orthologous group. As a result, we found a strong correlation between the evolutionary distance average and the proposed evolutionary plasticity index. Additionally, we found low evolutionary plasticity in <it>Saccharomyces cerevisiae </it>genes associated with inviability and <it>Mus musculus </it>genes associated with early lethality. At last, we plot the evolutionary plasticity value in different gene networks from yeast and humans. As a result, it was possible to discriminate among higher and lower plastic areas of the gene networks analyzed.</p> <p>Conclusions</p> <p>The distribution of gene families brings valuable information on evolutionary plasticity which might be related with genetic plasticity. Accordingly, it is possible to discriminate among conserved and plastic orthologous groups by evaluating their abundance and diversity across eukaryotes.</p> <p>Reviewers</p> <p>This article was reviewed by Prof Manyuan Long, Hiroyuki Toh, and Sebastien Halary.</p

O ENFERMEIRO ATUANDO NA PREVENÇÃO DAS ÚLCERAS DE PRESSÃO

Las úlceras de decúbito fueron y siguen siendo un cuidado importante en la enfermería. Sin embargo, comprender hoy la práctica del cuidar solo es posible a partir de una visión holística, un cuidar que ve a la persona integralmente. Por ese motivo, cuando se habla de prevención de úlceras es preciso conocer la estructura de la piel y su función para comprender mejor los fundamentos de prevención y cuidados eficaces. La manutención de la integridad de la piel es responsabilidad del Enfermero. Los mecanismos que causan las úlceras son innumerables y precisan ser atenuados o prevenidos completamente para que la integridad cutánea sea mantenida. Ante eso trazamos como objeto de estudio: El conocimiento por la Enfermería de la Escala Predictiva de Braden en la prevención de las úlceras de presión. Y como problema el siguiente cuestionamiento: ¿Cómo la enfermería sistematiza la asistencia en la prevención de las úlceras de presión? Objetivos: Identificar lo que la Enfermería conoce al respecto de la Escala predictiva de Braden (“Escala pronóstica de Braden); Comparar lo que saben con lo que hacen para prevenir las úlceras de presión. Metodología: En cuanto al tipo se trata de un estudio de caso, descriptivo, y utilizaremos el abordaje cuantitativo. La pesquisa tuvo como escenario la Unidad de Terapia Intensiva de una institución pública, de medio porte, clasificada como hospital general.As úlceras de decúbito foram e continuarão sendo um cuidado importante na enfermagem. Porém, hoje compreender a prática do cuidar, só é possível a partir de uma visão holística, um cuidar que veja a pessoa integralmente. Por esse motivo, quando se fala em prevenção de úlceras é preciso conhecer a estrutura da pele e sua função para compreender melhor os fundamentos de prevenção e cuidados eficazes com pele. A manutenção da integridade da pele é responsabilidade do Enfermeiro. Os mecanismos que causam as úlceras são inúmeros e precisam ser atenuados ou prevenidos completamente para que a integridade cutânea seja mantida. Diante disso, traçamos como objeto de estudo: O conhecimento pela Enfermagem da Escala Preditiva de Braden na prevenção das úlceras de pressão. E como problema o seguinte questionamento: Como a enfermagem sistematiza a assistência na prevenção das úlceras de pressão? Objetivos: Identificar o que a Enfermagem conhece a respeito de Escala preditiva de Braden; Comparar o que sabem com o que fazem para prevenir as úlceras de pressão. Metodologia: quanto à tipologia trata-se de um estudo de caso, descritivo e utilizaremos a abordagem quantitativa. A pesquisa teve como cenário a Unidade de Terapia Intensiva, de uma instituição pública, de médio porte, classificada como hospital geral

Uniform semiclassical trace formula for U(3) --> SO(3) symmetry breaking

We develop a uniform semiclassical trace formula for the density of states of a three-dimensional isotropic harmonic oscillator (HO), perturbed by a term $\propto r^4$. This term breaks the U(3) symmetry of the HO, resulting in a spherical system with SO(3) symmetry. We first treat the anharmonic term in semiclassical perturbation theory by integration of the action of the perturbed periodic HO orbits over the manifold $\mathbb{C}$P$^2$ which characterizes their 4-fold degeneracy. Then we obtain an analytical uniform trace formula which in the limit of strong perturbations (or high energy) asymptotically goes over into the correct trace formula of the full anharmonic system with SO(3) symmetry, and in the limit $\epsilon$ (or energy) $\to 0$ restores the HO trace formula with U(3) symmetry. We demonstrate that the gross-shell structure of this anharmonically perturbed system is dominated by the two-fold degenerate diameter and circular orbits, and {\it not} by the orbits with the largest classical degeneracy, which are the three-fold degenerate tori with rational ratios $\omega_r:\omega_\phi=N:M$ of radial and angular frequencies. The same holds also for the limit of a purely quartic spherical potential $V(r)\propto r^4$.Comment: LaTeX (revtex4), 26pp., 5 figures, 1 table; final version to be published in J. Phys. A (without appendices C and D

Stronger diversity effects with increased environmental stress : a study of multitrophic interactions between oak, powdery mildew and ladybirds

Recent research has suggested that increasing neighbourhood tree species diversity may mitigate the impact of pests or pathogens by supporting the activities of their natural enemies and/or reducing the density of available hosts. In this study, we attempted to assess these mechanisms in a multitrophic study system of young oak (Quercus), oak powdery mildew (PM, caused by Erysiphe spp.) and a mycophagous ladybird (Psyllobora vigintiduo-punctata). We assessed ladybird mycophagy on oak PM in function of different neighbourhood tree species compositions. We also evaluated whether these species interactions were modulated by environmental conditions as suggested by the Stress Gradient Hypothesis. We adopted a complementary approach of a field experiment where we monitored oak saplings subjected to a reduced rainfall gradient in a young planted forest consisting of different tree species mixtures, as well as a lab experiment where we independently evaluated the effect of different watering treatments on PM infections and ladybird mycophagy. In the field experiment, we found effects of neighbourhood tree species richness on ladybird mycophagy becoming more positive as the target trees received less water. This effect was only found as weather conditions grew drier. In the lab experiment, we found a preference of ladybirds to graze on infected leaves from trees that received less water. We discuss potential mechanisms that might explain this preference, such as emissions of volatile leaf chemicals. Our results are in line with the expectations of the Natural Enemies Hypothesis and support the hypothesis that biodiversity effects become stronger with increased environmental stress

Model Consistency for Distributed Collaborative Modeling

International audienceCurrent collaborative modeling tools use a centralized architecture , based on version control system, where models are updated asynchronously. These tools depend on a single server and are not completely adapted for collaborative modeling, where update reactivity is essential. In this paper, we propose a framework for building collabo-rative modeling tools which provides synchronous model update. The framework is based on a peer-to-peer architecture and uses a consistency algorithm for model updating

Ensemble Place Codes in Hippocampus: CA1, CA3, and Dentate Gyrus Place Cells Have Multiple Place Fields in Large Environments

Previously we reported that the hippocampus place code must be an ensemble code because place cells in the CA1 region of hippocampus have multiple place fields in a more natural, larger-than-standard enclosure with stairs that permitted movements in 3-D. Here, we further investigated the nature of hippocampal place codes by characterizing the spatial firing properties of place cells in the CA1, CA3, and dentate gyrus (DG) hippocampal subdivisions as rats foraged in a standard 76-cm cylinder as well as a larger-than-standard box (1.8 m×1.4 m) that did not have stairs or any internal structure to permit movements in 3-D. The rats were trained to forage continuously for 1 hour using computer-controlled food delivery. We confirmed that most place cells have single place fields in the standard cylinder and that the positional firing pattern remapped between the cylinder and the large enclosure. Importantly, place cells in the CA1, CA3 and DG areas all characteristically had multiple place fields that were irregularly spaced, as we had reported previously for CA1. We conclude that multiple place fields are a fundamental characteristic of hippocampal place cells that simplifies to a single field in sufficiently small spaces. An ensemble place code is compatible with these observations, which contradict any dedicated coding scheme