Avaliação de impactos ambientais de diferentes sistemas de produção de cana-de-açúcar: convencional e conservacionista.

Resumo: O setor sucroenergético brasileiro é responsável pela produção anual de mais de 38 milhões de toneladas de açúcar e cerca de 27 bilhões de litros de etanol. A pressão social por práticas ambientalmente mais aceitáveis tem levado o setor a modificar seu atual sistema de produção. Neste contexto de mudança se inclui a interrupção da queima pré-colheita, que por sua vez possibilita a adoção de técnicas já consolidadas em outros setores agrícolas, como o plantio direto. O objetivo deste trabalho foi comparar o desempenho ambiental de dois sistemas de cultivo de cana-de-açúcar, convencional e plantio direto em rotação com soja, especificamente quanto às etapas de pré-plantio e plantio. Ambos os sistemas foram empregados em uma usina paulista, localizada em área tradicional, mas sob bioma de cerrado. Os resultados mostraram que o sistema convencional implica em maior impacto na categoria "Mudanças Climáticas", e o de plantio direto na "Depleção Fóssil". Contudo, observou-se um melhor desempenho do sistema conservacionista, que agrega um produto adicional (e que apresenta menor carga ambiental), com amesma ocupação de terras. Conclui-se que é de extrema importância a busca por práticas agrícolas mais sustentáveis na cultura canavieira, que já começa a mostrar resultados positivos

The Antibacterial Protein Lysozyme Identified as the Termite Egg Recognition Pheromone

Social insects rely heavily on pheromone communication to maintain their sociality. Egg protection is one of the most fundamental social behaviours in social insects. The recent discovery of the termite-egg mimicking fungus ‘termite-ball’ and subsequent studies on termite egg protection behaviour have shown that termites can be manipulated by using the termite egg recognition pheromone (TERP), which strongly evokes the egg-carrying and -grooming behaviours of workers. Despite the great scientific and economic importance, TERP has not been identified because of practical difficulties. Herein we identified the antibacterial protein lysozyme as the TERP. We isolated the target protein using ion-exchange and hydrophobic interaction chromatography, and the MALDI-TOF MS analysis showed a molecular size of 14.5 kDa. We found that the TERP provided antibacterial activity against a gram-positive bacterium. Among the currently known antimicrobial proteins, the molecular size of 14.5 kDa limits the target to lysozyme. Termite lysozymes obtained from eggs and salivary glands, and even hen egg lysozyme, showed a strong termite egg recognition activity. Besides eggs themselves, workers also supply lysozyme to eggs through frequent egg-grooming, by which egg surfaces are coated with saliva containing lysozyme. Reverse transcript PCR analysis showed that mRNA of termite lysozyme was expressed in both salivary glands and eggs. Western blot analysis confirmed that lysozyme production begins in immature eggs in queen ovaries. This is the first identification of proteinaceous pheromone in social insects. Researchers have focused almost exclusively on hydrocarbons when searching for recognition pheromones in social insects. The present finding of a proteinaceous pheromone represents a major step forward in, and result in the broadening of, the search for recognition pheromones. This novel function of lysozyme as a termite pheromone illuminates the profound influence of pathogenic microbes on the evolution of social behaviour in termites

Academic freedom in Europe: reviewing UNESCO’s recommendation

This paper examines the compliance of universities in the European Union with the UNESCO Recommendation concerning the Status of Higher–Education Teaching Personnel, which deals primarily with protection for academic freedom. The paper briefly surveys the European genesis of the modern research university and academic freedom, before evaluating compliance with the UNESCO recommendation on institutional autonomy, academic freedom, university governance and tenure. Following from this, the paper examines the reasons for the generally low level of compliance with the UNESCO Recommendation within the EU states, and considers how such compliance could be improved

Explicit solutions to the semi-discrete modified KdV equation and motion of discrete plane curves

We construct explicit solutions to continuous motion of discrete plane curves described by a semi-discrete potential modified KdV equation. Explicit formulas in terms the $\tau$ function are presented. B\"acklund transformations of the discrete curves are also discussed. We finally consider the continuous limit of discrete motion of discrete plane curves described by the discrete potential modified KdV equation to motion of smooth plane curves characterized by the potential modified KdV equation

Landau Theory of the Finite Temperature Mott Transition

In the context of the dynamical mean-field theory of the Hubbard model, we identify microscopically an order parameter for the finite temperature Mott endpoint. We derive a Landau functional of the order parameter. We then use the order parameter theory to elucidate the singular behavior of various physical quantities which are experimentally accessible.Comment: 4 pages, 2 figure

Magnetic Phase Diagram and Metal-Insulator Transition of NiS2-xSex

Magnetic phase diagram of NiS2-xSex has been reexamined by systematic studies of electrical resistivity, uniform magnetic susceptibility and neutron diffraction using single crystals grown by a chemical transport method. The electrical resistivity and the uniform magnetic susceptibility exhibit the same feature of temperature dependence over a wide Se concentration. A distinct first order metal-insulator (M-I) transition accompanied by a volume change was observed only in the antiferromagnetic ordered phase for 0.50<x<0.59. In this region, the M-I transition makes substantial effects to the thermal evolution of staggered moments. In the paramagnetic phase, the M-I transition becomes broad; both the electrical resistivity and the uniform magnetic susceptibility exhibit a broad maximum around the temperatures on the M-I transition-line extrapolated to the paramagnetic phase.Comment: 6 pages, 8 figures, corrected EPS fil

Recoil and Threshold Corrections in Short-distance Cross Sections

We identify and resum corrections associated with the kinematic recoil of the hard scattering against soft-gluon emission in single-particle inclusive cross sections. The method avoids double counting and conserves the flow of partonic energy. It reproduces threshold resummation for high-p_T single-particle cross sections, when recoil is neglected, and Q_T-resummation at low Q_T, when higher-order threshold logarithms are suppressed. We exhibit explicit resummed cross sections, accurate to next-to-leading logarithm, for electroweak annihilation and prompt photon inclusive cross sections.Comment: minor modifications of the text, some references added. 51 pages, LaTeX, 6 figures as eps file

Discrete Integrable Systems and Hodograph Transformations Arising from Motions of Discrete Plane Curves

We consider integrable discretizations of some soliton equations associated with the motions of plane curves: the Wadati-Konno-Ichikawa elastic beam equation, the complex Dym equation, and the short pulse equation. They are related to the modified KdV or the sine-Gordon equations by the hodograph transformations. Based on the observation that the hodograph transformations are regarded as the Euler-Lagrange transformations of the curve motions, we construct the discrete analogues of the hodograph transformations, which yield integrable discretizations of those soliton equations.Comment: 19 page

Avaliação do ciclo de vida da produção de algodão para extração de nanofibras: sistema de produção em rotação com soja e forrageira.

Resumo: Os nanomateriais, por suas propriedades físico-químicas únicas, podem estabelecer interações imprevistas com substâncias naturalmente presentes nos componentes ambientais, fazendo-se indispensável a avaliação dos seus impactos ambientais potenciais. O objetivo deste trabalho foi avaliar a contribuição da fase agrícola da produção de algodão, matéria-prima para obtenção de nanofibras, no desempenho ambiental deste produto. Considerou-se o sistema de produção de algodão por plantio direto, em rotação com soja e forrageira. Para o sistema estudado, os impactos ambientais mais relevantes foram eutrofização de água doce e mudanças climáticas globais