On a study and applications of the Concentration-compactness type principle for Systems with critical terms in RN\mathbb{R}^{N}

In this paper, we obtain some important variants of the Lions and Chabrowski Concentration-compactness principle, in the context of fractional Sobolev spaces with variable exponents, especially for nonlinear systems. As an application of the results, we show the existence and assymptotic behaviour of nontrivial solutions for elliptic systems involving a new class of general nonlocal integrodifferential operators with exponent variables and critical growth conditions in $\mathbb{R}^{N}$

Interference and complementarity for two-photon hybrid entangled states

In this work we generate two-photon hybrid entangled states (HES), where the polarization of one photon is entangled with the transverse spatial degree of freedom of the second photon. The photon pair is created by parametric down-conversion in a polarization-entangled state. A birefringent double-slit couples the polarization and spatial degrees of freedom of these photons and finally, suitable spatial and polarization projections generate the HES. We investigate some interesting aspects of the two-photon hybrid interference, and present this study in the context of the complementarity relation that exists between the visibilities of the one- and two-photon interference patterns.Comment: 10 pages, 4 figures. Accepted in Physical Review

Ribosomal DNA heterochromatin in plants

The aim of this review is to integrate earlier results and recent findings to present the current state-of-the art vision concerning the dynamic behavior of the ribosomal DNA (rDNA) fraction in plants. The global organization and behavioral features of rDNA make it a most useful system to analyse the relationship between chromatin topology and gene expression patterns. Correlations between several heterochromatin fractions and rDNA arrays demonstrate the heterochromatic nature of the rDNA and reveal the importance of the genomic environment and of developmental controls in modulating its dynamicsFCT - Fundação para a Ciência e Tecnologi

Maximum-confidence discrimination among symmetric qudit states

We study the maximum-confidence (MC) measurement strategy for discriminating among nonorthogonal symmetric qudit states. Restricting to linearly dependent and equally likely pure states, we find the optimal positive operator valued measure (POVM) that maximizes our confidence in identifying each state in the set and minimizes the probability of obtaining inconclusive results. The physical realization of this POVM is completely determined and it is shown that after an inconclusive outcome, the input states may be mapped into a new set of equiprobable symmetric states, restricted, however, to a subspace of the original qudit Hilbert space. By applying the MC measurement again onto this new set, we can still gain some information about the input states, although with less confidence than before. This leads us to introduce the concept of "sequential maximum-confidence" (SMC) measurements, where the optimized MC strategy is iterated in as many stages as allowed by the input set, until no further information can be extracted from an inconclusive result. Within each stage of this measurement our confidence in identifying the input states is the highest possible, although it decreases from one stage to the next. In addition, the more stages we accomplish within the maximum allowed, the higher will be the probability of correct identification. We will discuss an explicit example of the optimal SMC measurement applied in the discrimination among four symmetric qutrit states and propose an optical network to implement it.Comment: 14 pages, 4 figures. Published versio

Avaliação econômica da implantação e manutenção de um sistema agroflorestal com cultivo diversificado.

Resumo: Este trabalho apresenta a análise dos custos de implantação e manutenção de um sistema agroflorestal com cultivos diversificados. Esta avaliação é uma etapa preliminar de uma análise integrada que considerará, além dos fatores socioeconômicos, a recuperação ambiental da área. São apresentados o modelo empregado no sistema, alguns resultados iniciais e os custos de implantação e manutenção. A análise dos dados mostra que houve uma concentração dos gastos na implantação e no primeiro ano deste sistema. Na implantação, o custo principal foi com a aquisição de mudas, enquanto na manutenção os custos se concentraram na mão de obra. Abstract: This paper presents an analysis of the costs of implementation and maintenance of a agroforestry system with diversified crops. This evaluation is a preliminary step in an integrated analysis that will consider also the environmental restoration of the area. The model used in the system, some initial results and the costs of implementation and maintenance are presented. The data analysis indicated that there was a concentration of spending in the implementation and first year of this system. The seedlings was the main cost in the deployment of the system, differently the costs are concentrated in manpower in themaintenance stage

Infecções parasitárias de híbridos tambatinga (Colossoma macropomum x Piaractus brachypomus) cultivados em pisciculturas de Macapá, Estado do Amapá.

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Balanço de energia em uma cultura de feijão caupi (Vigna unguiculata L.) no estado do Pará.

Este trabalho teve como objetivo estudar a variação do balanço de energia e analisar a partição do saldo de radiação em termos dos fluxos de calor latente e calor sensível, para a cultura de feijão caupi (Vigna unguiculata L.) Foram feitas medições contínuas dos fluxos de calor sensível, calor latente e saldo de radiação, no feijão caupi, cultivado na cidade de Tracuateua-PA, no período de agosto a setembro de 2002, usando-se a covariância dos vórtices turbulentos. O saldo de radiação representou, em média, 62% da radiação solar global. A maior porção do saldo de radiação foi usada como fluxo de calor sensível (61 %), enquanto o fluxo de calor latente respondeu apenas por 21 % do saldo de radiação. Esse baixo percentual do saldo de radiação usado como fluxo de calor latente ocorreu devido a restrições hídricas impostas pela falta de chuvas durante o período experimental