Quanto custa tratar as sementes de soja, milho e algodão com fungicidas?

As sementes de soja e os fungos; As sementes de milho e os fungos; As sementes de algodao e os fungos; Custo do tratamento de sementes

Magnetite and its transformation to hematite in a soil derived from steatite.

O presente trabalho objetivou caracterizar o mineral magnetico e identificar suas rotas pedogeneticas de transformacao em um solo formado sobre esteatito, de Minas Gerais, Brasil. O oxido de ferro isoestrutural ao espinelio foi identificado e caracterizado por analises quimicas, difracao de raios X, espectroscopia Mossbauer e medidas de magnetizacao de saturacao. Na rocha fresca, foi encontrada magnetita estequiometrica e bem cristalizada, com parametro da rede cubica, ao = 0.8407(5) nm. Nas fracoes areia e silte, foram detectadas magnetita parcialmente alterada e hematita estequiometrica e bem cristalizada, com parametros de rede hexagonal, a = 0.5036(3) nm e c = 1.375(4)nm. A ocorrencia dessas hematitas deveu-se principalmente a oxidacao do Fe2+ a Fe3+, no sitio octaedrico de magnetita, durante a pedogenese. Esse processo foi caracterizado pelo aparecimento de pequena quantidade de Fe3+ eletronicamente desacoplada, encontrada nas magnetitas parcialmente oxidadas, cujas formulas para as diferentes estequiometrias foram propostas. Verificou-se tambem pequena quantidade de ilmenita nas amostras de rocha e de solo

Fast ADMM for Semidefinite Programs with Chordal Sparsity

Many problems in control theory can be formulated as semidefinite programs (SDPs). For large-scale SDPs, it is important to exploit the inherent sparsity to improve the scalability. This paper develops efficient first-order methods to solve SDPs with chordal sparsity based on the alternating direction method of multipliers (ADMM). We show that chordal decomposition can be applied to either the primal or the dual standard form of a sparse SDP, resulting in scaled versions of ADMM algorithms with the same computational cost. Each iteration of our algorithms consists of a projection on the product of small positive semidefinite cones, followed by a projection on an affine set, both of which can be carried out efficiently. Our techniques are implemented in CDCS, an open source add-on to MATLAB. Numerical experiments on large-scale sparse problems in SDPLIB and random SDPs with block-arrow sparse patterns show speedups compared to some common state-of-the-art software packages

Designing antibiotic cycling strategies by determining and understanding local adaptive landscapes

The evolution of antibiotic resistance among bacteria threatens our continued ability to treat infectious diseases. The need for sustainable strategies to cure bacterial infections has never been greater. So far, all attempts to restore susceptibility after resistance has arisen have been unsuccessful, including restrictions on prescribing [1] and antibiotic cycling [2,3]. Part of the problem may be that those efforts have implemented different classes of unrelated antibiotics, and relied on removal of resistance by random loss of resistance genes from bacterial populations (drift). Here, we show that alternating structurally similar antibiotics can restore susceptibility to antibiotics after resistance has evolved. We found that the resistance phenotypes conferred by variant alleles of the resistance gene encoding the TEM {\beta}-lactamase (blaTEM) varied greatly among 15 different {\beta}-lactam antibiotics. We captured those differences by characterizing complete adaptive landscapes for the resistance alleles blaTEM-50 and blaTEM-85, each of which differs from its ancestor blaTEM-1 by four mutations. We identified pathways through those landscapes where selection for increased resistance moved in a repeating cycle among a limited set of alleles as antibiotics were alternated. Our results showed that susceptibility to antibiotics can be sustainably renewed by cycling structurally similar antibiotics. We anticipate that these results may provide a conceptual framework for managing antibiotic resistance. This approach may also guide sustainable cycling of the drugs used to treat malaria and HIV

A model based on Heisenberg’s theory for the eddy diffusivity in decaying turbulence applied to the residual layer

The problemof the theoretical derivation of a parameterization for the eddy diffusivity in decaying turbulence is addressed. This derivation makes use of the dynamical equation for the energy spectrum density and the classical statistical diffusion theory. The starting point is Heisenberg’s elementary decaying turbulence theory. The main assumption is related to the identification of a frequency, lying in the inertial subrange, characterizing the inertial energy transfer among eddies of different size. The resulting eddy diffusivity parameterization is then applied to the decay of convective turbulence in the residual layer. Besides the intrinsic scientific interest, this topic has relevance for mesoscale transport and diffusion simulations. The resulting expression for the eddy diffusivity cannot be solved analytically. For this reason an algebraic approximated formulation, giving nearly the same results as the exact expression, is also proposed

Estudo fitossociológico em área de vegetação campestre na região do Alto Camaquã.

Organizado por: Márcio Nunes Corrêa, Valmor João Bianchi, Jacira Bolacell Braga e Valdecir Carlos Ferri

Sucessão soja/soja safrinha em Mato Grosso do Sul: um modelo de produção com sustentação agronômica?

bitstream/item/136163/1/COT2015206-CORRIGIDO.pd