On a Three-Dimensional Gravity Model with Higher Derivatives

The purpose of this work is to present a model for 3D massive gravity with topological and higher-derivative terms. Causality and unitarity are discussed at tree-level. Power-counting renormalizability is also contemplated.Comment: 9 pages, Latex, no figures; to be published in Gen. Rel. Gra

Suppression of Anderson localization of light and Brewster anomalies in disordered superlattices containing a dispersive metamaterial

Light propagation through 1D disordered structures composed of alternating layers, with random thicknesses, of air and a dispersive metamaterial is theoretically investigated. Both normal and oblique incidences are considered. By means of numerical simulations and an analytical theory, we have established that Anderson localization of light may be suppressed: (i) in the long wavelength limit, for a finite angle of incidence which depends on the parameters of the dispersive metamaterial; (ii) for isolated frequencies and for specific angles of incidence, corresponding to Brewster anomalies in both positive- and negative-refraction regimes of the dispersive metamaterial. These results suggest that Anderson localization of light could be explored to control and tune light propagation in disordered metamaterials.Comment: 4 two-column pages, 3 figure

A heveicultura nas "áreas de escape" do Brasil.

Histórico sobre áreas de escapes para a cultura da seringueira no Brasil. A produção de borracha natural no Brasil. Performance dos clones. Alguns problemas nas áreas de escape.Material não convencional

Impacto de alterações de temperatura no crescimento e esporulação de Fusarium oxysporum f. sp. tracheiphilum.

A murcha-de-fusarium é uma severa doença do feijão-caupi. O desenvolvimento de estudos sobre este patossistema requer inoculações artificiais, sendo necessária a reprodução massal do inóculo. Sendo assim, o objetivo do trabalho foi determinar o comportamento de F. oxysporum f. sp. tracheiphilum quanto à produção de esporos e o crescimento vegetativo em diferentes temperaturas. Discos do micélio com 5 mm de diâmetro, foram transferidos para Placas de Petri contendo BDA, 15 , 20 , 25 , 30 e 35 ºC, sob fotoperíodo de 12 horas. Avaliou-se o diâmetro das colônias, durante 15 dias. Em câmara de Neubauer, quantificou-se o número de esporos produzidos em 1 mL de suspensão. A temperatura influenciou o crescimento micelial, sendo maior crescimento a 30º C. A maior produção de esporos ocorreu em 35º C. Verificou-se que a temperatura tem efeito no crescimento micelial e na produção de conídios de F. oxysporum f. sp. tracheiphilum, sendo que a faixa ótima, entre 30 e 35º C, otimizam o crescimento e a esporulação do fungo

Marcadores moleculares no estudo de distância genética entre grupos de caprinos autóctones do Nordeste: I-amostras de DNA.

Molecular marks in the study of genetic distance between local goats groups of northwest: I. DNA samples. Abstract - The groups of Brazilians goat of northeast are originally of units brought at the time of settling and had differentiated geenotipicaly due to the geographic isolation. The genetic groups MoxotÛ and Canindé had been homologated as distinct breed. Even so some authors support, under the historical point of view, that goat presented only diverse color coat pattern, but with a same genetic origin. To investigate the diversity and genetic distance of similar coat color pattern, this work harvested samples of the main destined flocks the conservation of genetic resources of Researchs Institutes in the Cear·, PiauÌ and Bahia. The samples of blood are stored in the Embrapa Caprinos and Embrapa Meio-Norte laboratories. Until the moment, 100 samples of the MoxotÛ breed had been sampled, 32 of the CanindÈ breed, 152 of the Marota breed, 45 of Azul breed and the 37 of the Repartida one. The samples of blood of 25 MoxotÛ, 25 Marota breed and 10 Azul breed has been extracted by the protocol of phenol. The markers investigated until the moment are the INRA006, INRA172, CSRC 0247 and ILSTS011. The data observed had been not yet analyze

Fast stable direct fitting and smoothness selection for Generalized Additive Models

Existing computationally efficient methods for penalized likelihood GAM fitting employ iterative smoothness selection on working linear models (or working mixed models). Such schemes fail to converge for a non-negligible proportion of models, with failure being particularly frequent in the presence of concurvity. If smoothness selection is performed by optimizing `whole model' criteria these problems disappear, but until now attempts to do this have employed finite difference based optimization schemes which are computationally inefficient, and can suffer from false convergence. This paper develops the first computationally efficient method for direct GAM smoothness selection. It is highly stable, but by careful structuring achieves a computational efficiency that leads, in simulations, to lower mean computation times than the schemes based on working-model smoothness selection. The method also offers a reliable way of fitting generalized additive mixed models

Quantitative magneto-optical investigation of superconductor/ferromagnet hybrid structures

We present a detailed quantitative magneto-optical imaging study of several superconductor/ferromagnet hybrid structures, including Nb deposited on top of thermomagnetically patterned NdFeB, and permalloy/niobium with erasable and tailored magnetic landscapes imprinted in the permalloy layer. The magneto-optical imaging data is complemented with and compared to scanning Hall probe microscopy measurements. Comprehensive protocols have been developed for calibrating, testing, and converting Faraday rotation data to magnetic field maps. Applied to the acquired data, they reveal the comparatively weaker magnetic response of the superconductor from the background of larger fields and field gradients generated by the magnetic layer.Comment: 21 pages, including 2 pages of supplementary materia

Effect of hyperbaric stress on yeast morphology: Study by automated image analysis

The effects of hyperbaric stress on the morphology of Saccharomyces cerevisiae were studied in batch cultures under pressures between 0.1 MPa and 0.6 MPa and different gas compositions (air, oxygen, nitrogen or carbon dioxide), covering aerobic and anaerobic conditions. A method using automatic image analysis for classification of S. cerevisiae cells based on their morphology was developed and applied to experimental data. Information on cell size distribution and bud formation throughout the cell cycle is reported. The results show that the effect of pressure on cell activity strongly depends on the nature of the gas used for pressurization. While nitrogen and air to a maximum of 0.6 MPa of pressure were innocuous to yeast, oxygen and carbon dioxide pressure caused cell inactivation, which was confirmed by the reduction of bud cells with time. Moreover, a decrease in the average cell size was found for cells exposed for 7.5 h to 0.6 MPa CO2.CAPES and CNPq (Brazil). Fundação para a Ciência e Tecnologia (Portugal)