Efeito de extratos de plantas sobre a mortalidade de ninfas de Bemisia tabaci (Genn.) biótipo B (Hemiptera: Aleyrodidae) em feijoeiro (Phaseolus vulgaris L.).

Neste trabalho, avaliou-se o efeito do nim indiano, fumo, arruda e açafrão sobre a mortalidade de ninfas de B. tabaci biótipo B, em casa de vegetação.bitstream/CNPAF/23009/1/comt_95.pd

Fluxo gênico em feijoeiro comum: ocorrência e possíveis conseqüências.

Neste documento é apresentada uma revisão sobre a capacidade de hibridização natural em Phaseolus vulgaris e suas conseqüências com relação à segurança ambiental do feijoeiro geneticamente modificado.bitstream/CNPAF/23818/1/doc_185.pd

ALTERNATIVE DIRECT INTERPOLATION BOUNDARY ELEMENT METHOD APPLIED TO ADVECTIVE-DIFFUSIVE PROBLEMS WITH VARIABLE VELOCITY FIELD

The wide range of physical phenomena of industrial interest which can be properly represented by advection-diffusion transport models motivates a constant effort in the development of new numerical methods capable of dealing with strong advective effects such as compressibility ones. The recent direct interpolation technique (DIBEM) proved to be an accurate and reliable tool for the representation of problems with constant velocity field and initial tests were also performed for problems with variable velocity field, where the results are reasonably satisfactory, but not so robust, since the integral relative to the velocity divergence, in general, seems to disturb the performance of the formulation. The current article presents a new formulation of the direct interpolation technique for solving variable velocity problems with non-zero velocity divergence. The accuracy of the new proposal is measured against a known analytical solution and, also, contrasted with the classical formulation of DIBEM and dual reciprocity technique (DRBEM) for the same case. Preliminary results show that the alternative DIBEM formulation proposed promotes a consistent improvement in precision, outperforming the two techniques in cross-comparison

Aplicação do Método de Elementos de Contorno Com Integração Direta Regularizada a Problemas Advectivo-difusivos Bidimensionais

As formulações mais usuais do método dos elementos de contorno para resolver problemas advectivos difusivos apresentam dificuldades significativas no tratamento do termo de transporte, por distintas razões. Enquanto a formulação clássica, que usa a solução fundamental advectivo-difusiva, é limitada para casos de campos de velocidade variável, a formulação de dupla reciprocidade (MECDR) apresenta problemas de precisão, sendo incapaz de produzir resultados satisfatórios, mesmo em problemas com números Peclét apenas moderados. Este trabalho aplica a recente técnica de interpolação direta regularizada com funções de base radial (MECIDR) para modelar o termo advectivo, permitindo assim uma boa precisão em problemas dominados pela advecção. O MECID apresentou resultados superiores à formulação com dupla reciprocidade em várias aplicações, como nos casos regidos pelas equações de Poisson e Helmholtz e, portanto, a sua extensão aos problemas advectivos-difusivos é uma consequência natural do seu desenvolvimento. Para avaliar o desempenho desta formulação, este projeto traz problemas-teste com solução analítica conhecida e já simulados pelas formulações anteriormente mencionadas, para expor a aplicabilidade e adequação do MECIDR neste contexto. Palavras chave: Integração Direta, Problemas Advectivos-Difusivos, Processo de Regularização, Método de Elementos de Contorn

Entropy and Poincar\'e recurrence from a geometrical viewpoint

We study Poincar\'e recurrence from a purely geometrical viewpoint. We prove that the metric entropy is given by the exponential growth rate of return times to dynamical balls. This is the geometrical counterpart of Ornstein-Weiss theorem. Moreover, we show that minimal return times to dynamical balls grow linearly with respect to its length. Finally, some interesting relations between recurrence, dimension, entropy and Lyapunov exponents of ergodic measures are given.Comment: 11 pages, revised versio

Both Palatable And Unpalatable Butterflies Use Bright Colors To Signal Difficulty Of Capture To Predators

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Birds are able to recognize and learn to avoid attacking unpalatable, chemically defended butterflies after unpleasant experiences with them. It has also been suggested that birds learn to avoid prey that are efficient at escaping. This, however, remains poorly documented. Here, we argue that butterflies may utilize a variety of escape tactics against insectivorous birds and review evidence that birds avoid attacking butterflies that are hard to catch. We suggest that signaling difficulty of capture to predators is a widespread phenomenon in butterflies, and this ability may not be limited to palatable butterflies. The possibility that both palatable and unpalatable species signal difficulty of capture has not been fully explored, but helps explain the existence of aposematic coloration and escape mimicry in butterflies lacking defensive chemicals. This possibility may also change the role that putative Mullerian and Batesian mimics play in a variety of classical mimicry rings, thus opening new perspectives in the evolution of mimicry in butterflies.452107113FAPDF/CNPq/Pronex [563/2009]Brazilian Research Council [302585/2011-7]Brazilian Research Council (SISBIOTA-Brasil/CNPq) [563332/2010-7]National Science Foundation [DEB-1256742]FAPESP (BIOTA-FAPESP Program) [2011/50225-3]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Toxicity of neem oil to Bemisia tabaci biotype B nymphs reared on dry bean.

O objetivo deste trabalho foi determinar o estágio ninfal de Bemisia tabaci biótipo B mais suscetível ao óleo de nim (Azadirachta indica A. Juss.) aplicado em feijoeiro (Phaseolus vulgaris L.), em casa telada. Foram avaliados o tempo letal (TL) e concentração letal (CL) do óleo comercial de sementes de nim Dalneem. Para CL, concentrações de 0, 0,1, 0,25, 0,5, 1 e 2% do produto foram pulverizadas diretamente sobre as ninfas em cada ínstar. Para TL, o produto foi avaliado a 0, 0,5 e 1% de óleo de nim em cada ínstar. Ninfas vivas e mortas foram contadas cinco dias após a pulverização para CL e diariamente para TL durante seis dias. Para o quarto ínstar, a CL50 foi de 0,56% de óleo de nim. Considerando todos os ínstares, CL50 e CL95 foram estimadas em 0,32 e 2,78% de óleo de nim, respectivamente. Os TL50 para 1% de nim foram estimados em 2,46, 4,45, 3,02 e 6,98 dias para o primeiro, segundo, terceiro e quarto ínstares, respectivamente. Os TL50 estimados para 0,5 e 1% de óleo de nim foram de cinco e quatro dias, respectivamente, considerando todos os ínstares. No sexto dia, foi observada mortalidade superior a 80% para o primeiro, segundo e terceiro ínstares a 1% de óleo de nim. Os três primeiros ínstares foram mais suscetíveis ao óleo de nim que o quarto ínstar

Impact of inter-core crosstalk on the performance of multi-core fibers-based SDM systems with coherent detection

Inter-core crosstalk (ICXT) can limit the multi-core fiber (MCF) systems performance and transmission reach. Over the last years, the impact of the ICXT on the performance of MCF optical communication systems with coherent detection has been investigated in several works. However, the influence of the MCF parameters and transmitted signal characteristics on the ICXT mechanism and the degradation induced by it on the performance of coherent detection MCF systems are still to be completely assessed. In this work, the impact of the ICXT on the performance of coherent detection MCF-based transmission systems is assessed through numerical simulation considering fiber linear propagation. The metrics used to assess the MCF system performance are the bit error rate (BER) and the optical signal-to-noise ratio (OSNR) penalty due to the ICXT. Our results show that the BER and the OSNR penalty due to the detected ICXT, in MCF-based systems with coherent detection, are influenced by the s kew, time misalignment between the transmitted signals and the roll-off factor of the transmitted signals. In the range of skew and roll-off factors analyzed, the maximum reduction of maximum ICXT level for a 1 dB OSNR penalty by appropriate choice of skew and roll-off factor does not exceed 1.7 dB.info:eu-repo/semantics/acceptedVersio

Inter-core crosstalk dependence on design parameters in coherent detection weakly-coupled multicore fiber systems

We assess, through numerical simulation, the dependence of the variance of the inter-core crosstalk (ICXT) and the maximum allowable ICXT level on the design parameters of coherent detection MCF systems. The analysed design parameters are the order of the quadrature amplitude modulation (QAM) signals, roll-off factor, time misalignment between the signal in different cores and skew between cores. The results show that, when the roll-off factor is 0, the maximum allowable ICXT level is independent of the skew and decreases for higher QAM orders. For a roll-off factor of 1, the maximum allowable ICXT level depends on the skew and time misalignment of core signals. In this case, the maximum allowable ICXT level increases by 3.6 dB relative to the case of roll-off factor of 0 with null skew, and by 2 dB, when the skew is much higher than the symbol period.info:eu-repo/semantics/acceptedVersio

Analysis of inter-core crosstalk in weakly-coupled multi-core fiber coherent systems

The influence of the inter-core crosstalk (ICXT) on the performance of weakly-coupled multi-core fiber (WC-MCF) systems with coherent detection and arbitrary inter-core skew is studied numerically and analytically. We analyze the evolution of the instantaneous ICXT power, induced by polarization division multiplexed quadrature amplitude modulation signals, short term average crosstalk (STAXT), and detected ICXT components along the time to get insight on how the ICXT affects the coherent system performance. Numerical results show that, with low skew-symbol rate product ($\ll$1), the STAXT can have large fluctuations along the time and the variance of the detected ICXT can also have large fluctuations along the time, causing large variations of the bit error rate (BER) along time. With large skew-symbol rate product ($\gg$1), the STAXT is almost constant along the time and, although the detected ICXT varies along time, the detected ICXT variance is almost constant along time leading to very small fluctuations of BER along time. Analytical expressions for the variance of the coherently detected ICXT, average BER and optical signal-to-noise ratio (OSNR) penalty are proposed and shown to agree with Monte-Carlo simulation results for arbitrary skew, modulation format order, and roll-off factor of the transmitted signals. Numerical results show that the maximum allowable ICXT level for 1 dB OSNR penalty increases when the skew augments and can reach 1.3 dB for a roll-off factor of 1. For most cases of interest of low roll-off factor, the increase of the maximum allowable ICXT level is very small. It is shown that the OSNR penalty estimates agree quite well with other authors' experimental results (with nearly zero roll-off factor).info:eu-repo/semantics/acceptedVersio