Riqueza de espécies, estrutura e composição florística de uma floresta secundária de 40 anos no leste da Amazônia.

A perda de florestas naturais devido a pressões antrópicas levou as florestas secundárias a ocupar uma grande proporção de áreas no leste da Amazônia. Com o objetivo de conhecer as características de uma comunidade arbórea e a estrutura populacional das espécies mais representativas, foram investigadas a riqueza de espécies, a estrutura e a composição florística de uma floresta secundária de 40 anos no município de Bragança (01°11'S e 46°40'W), Estado do Pará, Brasil. A amostragem contou com todos os indivíduos de espécies arbóreas (exceto Arecaceae) com DAP > 5 cm em 150 quadrados de 10×10 m. Foram registrados 2.934 indivíduos em 154 espécies, 101 gêneros e 40 famílias. A densidade foi de 1.956,00 ± 643,45 ind ha-1 e a área basal de 17,358 ± 7,952 m2 ha-1 com um índice de diversidade de Shannon de 4,030 nats. ind.-1. As espécies com a maior abundância de indivíduos foram Myrcia bracteata, Casearia arborea e Maprounea guianensis. As com maior área basal foram Tapirira guianensis, Croton matourensis e Maprounea guianensis. A riqueza de espécies adaptou-se ao modelo de distribuição lognormal apenas para área basal e não para número de indivíduos. Em 40 anos de sucessão, esta floresta mostra uma grande diversidade de espécies e baixa área basal

Bilingual access of homonym meanings : individual differences in bilingual access of homonym meanings

The goal of the present study was to identify the cognitive processes that underlie lexical ambiguity resolution in a second language (L2). We examined which cognitive factors predict the efficiency in accessing subordinate meanings of L2 homonyms in a sample of highly-proficient, Spanish–English bilinguals. The predictive ability of individual differences in (1) homonym processing in the L1, (2) working memory capacity and (3) sensitivity to cross-language form overlap were examined. In two experiments, participants were presented with cognate and noncognate homonyms as either a prime in a lexical decision task (Experiment 1) or embedded in a sentence (Experiment 2). In both experiments speed and accuracy in accessing subordinate meanings in the L1 was the strongest predictor of speed and accuracy in accessing subordinate meanings in the L2. Sensitivity to cross-language form overlap predicted performance in lexical decision while working memory capacity predicted processing in sentence comprehension

A expressividade na dança: visão do profissional

Este estudo, de natureza qualitativa, teve como objetivo verificar como o conteúdo expressivo é inserido em aulas de dança em academias, na visão dos profissionais da área e foi desenvolvido em duas etapas, sendo a primeira uma revisão de literatura sobre as definições, procedimentos pedagógicos e objetivos relativos às temáticas da dança e expressividade, e a segunda referente a uma pesquisa exploratória, utilizando-se como instrumento um questionário com perguntas abertas, aplicado aos professores de dança das academias da Cidade de Rio Claro, S.P. Os dados coletados foram analisados descritivamente, através de análise de conteúdo e indicam que a expressividade fica em segundo plano, em função de uma possível prioridade dada ao trabalho técnico, indicando uma dissonância entre a atitude positiva dos próprios profissionais em relação à aceitação do valor da expressividade na dança, e a ação pedagógica, na qual é observada a ausência de trabalho especificamente expressivo

Simplified stress analysis of hybrid (bolted/bonded) joints

The load transfer in hybrid (bolted/bonded) – denoted HBB – single-lap joints is complicated due to the association of two different transfer modes (discrete and continuous) through elements with different stiffnesses. The Finite Element (FE) method can be used to address the stress analysis of those joints. However, analyses based on FE models are computationally expensive and it would be profitable to use simplified approaches enabling extensive parametric studies. Two among the authors of this paper participated in the development of a dedicated 1D-beam approach (Paroissien 2007). This paper presents an extension of this framework enabling (i) the analysis of HBB joints made of dissimilar laminated or monolithic adherends, and (ii) the introduction of non linear material behaviour for both the adhesive layer and the fasteners. The output data are the distributions of displacements and forces in the adherends and fasteners, as well as those of adhesive shear and peeling stresses, allowing for a fast assessment of the material behaviour and strength prediction of HBB joints. The use of this model is illustrated in the identification of the failure mechanisms of HBB joints under quasistatic loadings, based on experimental and numerical tests on single-lap HBB joint. It is worth mentioning that the model can support pure bonded and pure bolted configurations. It can be used during the presizing phase at the design office (possibly independently on commercial software), to obtain quickly mechanical performances and to help in decision making. Moreover, it was shown that the judicious choice of the adhesive material allows for a significant increase of the static and fatigue strength compared to pure bolted or bonded corresponding configurations (Kelly 2006) (Paroissien 2006). The model can then be used to formulate at best adhesive materials to optimize the mechanical performance of HBB joints according to work specifications

The simulation of action disorganisation in complex activities of daily living

Action selection in everyday goal-directed tasks of moderate complexity is known to be subject to breakdown following extensive frontal brain injury. A model of action selection in such tasks is presented and used to explore three hypotheses concerning the origins of action disorganisation: that it is a consequence of reduced top-down excitation within a hierarchical action schema network coupled with increased bottom-up triggering of schemas from environmental sources, that it is a more general disturbance of schema activation modelled by excessive noise in the schema network, and that it results from a general disturbance of the triggering of schemas by object representations. Results suggest that the action disorganisation syndrome is best accounted for by a general disturbance to schema activation, while altering the balance between top-down and bottom-up activation provides an account of a related disorder - utilisation behaviour. It is further suggested that ideational apraxia (which may result from lesions to left temporoparietal areas and which has similar behavioural consequences to action disorganisation syndrome on tasks of moderate complexity) is a consequence of a generalised disturbance of the triggering of schemas by object representations. Several predictions regarding differences between action disorganisation syndrome and ideational apraxia that follow from this interpretation are detailed

Frisbee – A Platform for a Small Satellite Science Swarms

The FRISBEE multi-mission platform is presented, alongside the mission concept for SWARM (Space Weather Advanced Research Mission), a fleet of 30 or more microsatellites launched in groups of 5 and covering a range of local times and inclinations. The aim of this mission is to develop an understanding of the dynamic, global, and multiscale solar terrestrial interactions. The scientific payload is restricted to a dc magnetometer and electrostatic charged particle (ion and electron) analyser, providing both high time resolution and characterisation of collisionless plasma processes. The baseline satellite swarm can be launched in a variety of configurations and be augmented by future launches of identical satellites to provide greater coverage and density of measurement. The satellites require only loose formation control to ensure equal separation throughout the set of orbits defined in this document. The individual satellites are spin stabilized and each have a mass \u3c 25 kg. This mission represents the next step in understanding the solar terrestrial interaction and the potential results will be of great interest to the space science community at large. This mission has a true requirement for a swarm such that it can sample the magnetosphere in three dimensions and with sufficient density of measurements. The spacecraft required for this proposed mission could be designed and built within 24 months as most of the platform and payload technologies are re-used from previous missions. The mission has the potential for international collaboration, with provision of spacecraft platforms and world-leading scientific research. A demonstration of this mission has been down-selected by the Particle Physics and Astronomy Research Council (PPARC) for potential funding in the UK National MOSAIC small satellite programme

On the well-posedness of the stochastic Allen-Cahn equation in two dimensions

White noise-driven nonlinear stochastic partial differential equations (SPDEs) of parabolic type are frequently used to model physical and biological systems in space dimensions d = 1,2,3. Whereas existence and uniqueness of weak solutions to these equations are well established in one dimension, the situation is different for d \geq 2. Despite their popularity in the applied sciences, higher dimensional versions of these SPDE models are generally assumed to be ill-posed by the mathematics community. We study this discrepancy on the specific example of the two dimensional Allen-Cahn equation driven by additive white noise. Since it is unclear how to define the notion of a weak solution to this equation, we regularize the noise and introduce a family of approximations. Based on heuristic arguments and numerical experiments, we conjecture that these approximations exhibit divergent behavior in the continuum limit. The results strongly suggest that a series of published numerical studies are problematic: shrinking the mesh size in these simulations does not lead to the recovery of a physically meaningful limit.Comment: 21 pages, 4 figures; accepted by Journal of Computational Physics (Dec 2011

Strong correlations between text quality and complex networks features

Concepts of complex networks have been used to obtain metrics that were correlated to text quality established by scores assigned by human judges. Texts produced by high-school students in Portuguese were represented as scale-free networks (word adjacency model), from which typical network features such as the in/outdegree, clustering coefficient and shortest path were obtained. Another metric was derived from the dynamics of the network growth, based on the variation of the number of connected components. The scores assigned by the human judges according to three text quality criteria (coherence and cohesion, adherence to standard writing conventions and theme adequacy/development) were correlated with the network measurements. Text quality for all three criteria was found to decrease with increasing average values of outdegrees, clustering coefficient and deviation from the dynamics of network growth. Among the criteria employed, cohesion and coherence showed the strongest correlation, which probably indicates that the network measurements are able to capture how the text is developed in terms of the concepts represented by the nodes in the networks. Though based on a particular set of texts and specific language, the results presented here point to potential applications in other instances of text analysis.Comment: 8 pages, 8 figure

Antiviral activity of animal venom peptides and related compounds

Viruses exhibit rapid mutational capacity to trick and infect host cells, sometimes assisted through virus-coded peptides that counteract host cellular immune defense. Although a large number of compounds have been identified as inhibiting various viral infections and disease progression, it is urgent to achieve the discovery of more effective agents. Furthermore, proportionally to the great variety of diseases caused by viruses, very few viral vaccines are available, and not all are efficient. Thus, new antiviral substances obtained from natural products have been prospected, including those derived from venomous animals. Venoms are complex mixtures of hundreds of molecules, mostly peptides, that present a large array of biological activities and evolved to putatively target the biochemical machinery of different pathogens or host cellular structures. In addition, non-venomous compounds, such as some body fluids of invertebrate organisms, exhibit antiviral activity. This review provides a panorama of peptides described from animal venoms that present antiviral activity, thereby reinforcing them as important tools for the development of new therapeutic drugs