Noncommutative associative superproduct for general supersymplectic forms

We define a noncommutative and nonanticommutative associative product for general supersymplectic forms, allowing the explicit treatment of non(anti)commutative field theories from general nonconstant string backgrounds like a graviphoton field. We propose a generalization of deformation quantization a la Fedosov to superspace, which considers noncommutativity in the tangent bundle instead of base space, by defining the Weyl super product of elements of Weyl super algebra bundles. Super Poincare symmetry is not broken and chirality seems not to be compromised in our formulation. We show that, for a particular case, the projection of the Weyl super product to the base space gives rise the Moyal product for non(anti)commutative theories.Comment: 22 pages, revtex4. References added. Comments added. Includes additional theorem proof

Avaliação toxicopatológica em ratos expostos à Pseudomonas putida.

A bactéria Pseudomonas putida tem se mostrado hábil na degradação de vários xenobióticos, porém são poucos os estudos a respeito da segurança de seu uso para a saúde humana. A fim de avaliar os possíveis efeitos toxicopatológicos da bactéria, uma linhagem de P. putida, envolvida na biodegradação do herbicida propanil, foi administrada a ratos, em suspensões de 108 ufc mL?1 via oral. Os animais foram observados diariamente, não havendo alterações clínicas ou quaisquer lesões em órgãos internos após a exposição à bactéria. Os animais também foram submetidos à necropsia em diferentes intervalos após a administração, com a retirada de vários órgãos para verificar a presença da bactéria nesses tecidos. A bactéria não cresceu nas amostras biológicas após 3 e 24 h da exposição, mas sim após 16 h, no pulmão no grupo tratado com a bactéria ativa. A confirmação em nível de espécie das colônias isoladas nos órgãos foi realizada pela análise do perfil dos ácidos graxos de membrana. O protocolo utilizado mostrou-se adequado para analisar a segurança de uso dessa bactéria em mamíferos

Dust growth in molecular cloud envelopes: a numerical approach

Variations in the grain size distribution are to be expected in the interstellar medium (ISM) due to grain growth and destruction. In this work, we present a dust collision model to be implemented inside a magnetohydrodynamical (MHD) code that takes into account grain growth and shattering of charged dust grains of a given composition (silicate or graphite). We integrate this model in the MHD code Athena, and builds on a previous implementation of the dynamics of charged dust grains in the same code. To demonstrate the performance of this coagulation model, we study the variations in the grain size distribution of a single-sized population of dust with radius 0.05 $\mu$m inside several dust filaments formed during a 2D MHD simulation. We also consider a realistic dust distribution with sizes ranging from 50 \AA~to 0.25 $\mu$m and analyze both the variations in the size distribution for graphite and silicates, as well as of the far ultraviolet extinction curve. From the obtained results, we conclude that the methodology here presented, based on the MHD evolution of the equation of motion for a charged particle, is optimal for studying the coagulation of charged dust grains in a diffuse regime such as a molecular cloud envelope. Observationally, these variations in the dust size distribution are translated into variations in the far ultraviolet extinction curve, and they are mainly caused by small graphite dust grains.Comment: Accepted for publication in Ap

An effective singular oscillator for Duffin-Kemmer-Petiau particles with a nonminimal vector coupling: a two-fold degeneracy

Scalar and vector bosons in the background of one-dimensional nonminimal vector linear plus inversely linear potentials are explored in a unified way in the context of the Duffin-Kemmer-Petiau theory. The problem is mapped into a Sturm-Liouville problem with an effective singular oscillator. With boundary conditions emerging from the problem, exact bound-state solutions in the spin-0 sector are found in closed form and it is shown that the spectrum exhibits degeneracy. It is shown that, depending on the potential parameters, there may or may not exist bound-state solutions in the spin-1 sector.Comment: 1 figure. arXiv admin note: substantial text overlap with arXiv:1009.159

Resíduos de agrotóxicos em grãos, casca e farelo de arroz irrigado.

bitstream/item/78838/1/Circular-130.pd