Quantum chaotic resonances from short periodic orbits

We present an approach to calculating the quantum resonances and resonance wave functions of chaotic scattering systems, based on the construction of states localized on classical periodic orbits and adapted to the dynamics. Typically only a few of such states are necessary for constructing a resonance. Using only short orbits (with periods up to the Ehrenfest time), we obtain approximations to the longest living states, avoiding computation of the background of short living states. This makes our approach considerably more efficient than previous ones. The number of long lived states produced within our formulation is in agreement with the fractal Weyl law conjectured recently in this setting. We confirm the accuracy of the approximations using the open quantum baker map as an example.Comment: 4 pages, 4 figure

Semiclassical structure of chaotic resonance eigenfunctions

We study the resonance (or Gamow) eigenstates of open chaotic systems in the semiclassical limit, distinguishing between left and right eigenstates of the non-unitary quantum propagator, and also between short-lived and long-lived states. The long-lived left (right) eigenstates are shown to concentrate as $\hbar\to 0$ on the forward (backward) trapped set of the classical dynamics. The limit of a sequence of eigenstates $\{\psi(\hbar)\}_{\hbar\to 0}$ is found to exhibit a remarkably rich structure in phase space that depends on the corresponding limiting decay rate. These results are illustrated for the open baker map, for which the probability density in position space is observed to have self-similarity properties.Comment: 4 pages, 4 figures; some minor corrections, some changes in presentatio

Gravitational Laser Back-Scattering

A possible way of producing gravitons in the laboratory is investigated. We evaluate the cross section electron + photon $\rightarrow$ electron + graviton in the framework of linearized gravitation, and analyse this reaction considering the photon coming either from a laser beam or from a Compton back-scattering process.Comment: 11 pages, 2 figures (available upon request), RevTeX, IFT-P.03/9

Performance of an Operating High Energy Physics Data Grid: D0SAR-Grid

The D0 experiment at Fermilab's Tevatron will record several petabytes of data over the next five years in pursuing the goals of understanding nature and searching for the origin of mass. Computing resources required to analyze these data far exceed capabilities of any one institution. Moreover, the widely scattered geographical distribution of D0 collaborators poses further serious difficulties for optimal use of human and computing resources. These difficulties will exacerbate in future high energy physics experiments, like the LHC. The computing grid has long been recognized as a solution to these problems. This technology is being made a more immediate reality to end users in D0 by developing a grid in the D0 Southern Analysis Region (D0SAR), D0SAR-Grid, using all available resources within it and a home-grown local task manager, McFarm. We will present the architecture in which the D0SAR-Grid is implemented, the use of technology and the functionality of the grid, and the experience from operating the grid in simulation, reprocessing and data analyses for a currently running HEP experiment.Comment: 3 pages, no figures, conference proceedings of DPF04 tal

Stephanofilaria sp em bovinos do município de São Carlos, Estado de São Paulo.

Estudos clínicas e laboratórios em ulceras do tipo "Chagas de Verão" em bovinos do Município de São Carlos. Observou-se uma dermatite nodular ulcerativa na região da quartela, jarrete, cruz, cabeça, teta, paleta

Dermatite ulcerosa em bovinos provocada por Stephanofilaria.

Em um rebanho leiteiro localizado na cidade de São Carlos-SP, foram constatados cinco casos de dermatite ulcerosa tendo como agente etiologico a Stephanofilaria spp. As lesões se localizaram na inserção da cauda, ubere, coxa e graupa. O diagnóstico foi feito por esfregaço e impressões obtidas de raspado e pele da borda da ulcera, coradas com Giemsa e também com vermelho Congo sendo que este permitiu melhor visualização do parasita. O tratamento foi feito com tricloforn, obtendo-se a cura dos animais em quinze dias

Suplementação estratégica com mistura mineral na recria de novilhas sob condições de pastejo.

Comparar o ganho de peso de 60 novilhas (Canchim, mestiças leiteiras e europeu - zebu), mantidas em pastagens de brachiaria decumbens

In silico characterization of microRNAs-like sequences in the genome of Paracoccidioides brasiliensis

Eukaryotic cells have different mechanisms of post-transcriptional regulation. Among these mechanisms, microRNAs promote regulation of targets by cleavage or degradation of the mRNA. Fungi of the Paracoccidioides complex are the etiological agents of the main systemic mycosis of Latin America. These fungi present a plasticity to adapt and survive in different conditions, and the presence of microRNAs-like molecules could be part of the mechanisms that provide such plasticity. MicroRNAs produced by the host influence the progression of this mycosis in the lungs besides regulating targets involved in apoptosis in macrophage, activation of T and B cells and the production of cytokines. Therefore, this work analyzed the presence of regions in the genome of this fungus with a potential to encode microRNAs-like molecules. Here we show by analysis of sequence similarity the presence of 18 regions, putatively coding for microRNAs-like molecules in the Paracoccidioides brasiliensis genome. We also described the conservation of dicer and argonaut proteins and the cognate transcripts induced in the yeast parasitic phase. This work represents a starting point for the analysis of the presence of those molecules in the morphological stages of the fungus and their role in fungal development

Long-lasting systematic roguing for effective management of CABMV in passion flower orchards through maintenance of separated plants.

In Brazil, passion flower is grown across almost the entire country. The predominant disease of the passion flower cropis passion fruit woodiness, caused by the potyvirus cowpea aphid-borne mosaic virus (CABMV), and transmitted byaphids in a nonpersistent manner. The disease reduces the useful life of the orchard from 36 months to approximately18 months. Up to now, there has not been an efficient method for disease management. The aim of this work was toevaluate the efficiency of systematic roguing of diseased plants through weekly inspections, for disease management inthe field. The latent and incubation periods of CABMV in passion flower vines were determined in order to optimizeroguing efficiency. Passion fruit plants inoculated with CABMV started to act as sources of inoculum from 3 days afterinoculation (DAI), and the symptoms were expressed, on average, at 8 DAI. Five field experiments, conducted in thestates of S~ao Paulo and Bahia, Brazil, demonstrated that systematic roguing of diseased plants was significantly efficientfor managing passion fruit woodiness disease. In order to facilitate identification and subsequent removal of theinfected plants, they need to be grown separately. This cultural practice can be recommended for managing passionfruit woodiness disease, provided it is applied on a regional scale by all passion fruit growers. The development ofsome pilot plantings for the application of roguing in a passion flower-producing region is recommended to validatethe use of this technique for managing passion fruit woodiness disease