Identification of resistance to Bean Rugose Mosaic Virus (BRMV) in accesses of common bean germplasm.

The disease known as bean rugose mosaic, also known as ?mosaico-em-desenho? caused by Bean rugose mosaic virus (BRMV), has been recently observed in common bean (Phaseolus vulgaris L.) fields at EMBRAPA Rice and Beans, located in Santo Antonio de Goias, Goias State, Brazil. The importance of this disease increases especially in conditions that enable infection of young plants, when there is the presence of other viruses and under sequential cultivation of susceptible common bean varieties

Interference effects in above-threshold ionization from diatomic molecules: determining the internuclear separation

We calculate angle-resolved above-threshold ionization spectra for diatomic molecules in linearly polarized laser fields, employing the strong-field approximation. The interference structure resulting from the individual contributions of the different scattering scenarios is discussed in detail, with respect to the dependence on the internuclear distance and molecular orientation. We show that, in general, the contributions from the processes in which the electron is freed at one center and rescatters off the other obscure the interference maxima and minima obtained from single-center processes. However, around the boundary of the energy regions for which rescattering has a classical counterpart, such processes play a negligible role and very clear interference patterns are observed. In such energy regions, one is able to infer the internuclear distance from the energy difference between adjacent interference minima.Comment: 10 pages, 8 figures; discussions slightly modified and an additional figure inserted for clarit

Development of biocolonization resistant mortars: preliminary results

Restoration of Buildings and Monuments, vol. 13, nº 6 (2007), p.389-400The negative impact of biocolonization on buildings, particularly rendered ones, prompted the evaluation of a hydraulic mortar formulation to which copper metal, either as a powder or as fibres, was added as a means to control this problem. The study used in situ exposure in a location prone to biocolonization for over nine years. The results have proved that over this time period, no biocolonization occurred on samples containing 0.35 % by weight of copper powder with regards to the dry mortar mix. The mortar proved to acquire a slightly bluer-green hue which diminished after the nine year outdoor exposure. The mortars formulated with copper have a lower porosity as well as a lower capillary water absorption coefficient a definite advantage for their eventual life span. On the other hand, the mechanical resistance is slightly decreased but not significantly so. Further studies are envisioned to assess the performance with other types of binder, such as aerial lime

Host adaptation to viruses relies on few genes with different cross-resistance properties

The deposited article is a post-print version and has peer review. This deposit is composed by the main article, and it hasn't any supplementary materials associated. The supplementary materials of the publication are only present in the editor's page of this article. This publication hasn't any creative commons license associated.Host adaptation to one parasite may affect its response to others. However, the genetics of these direct and correlated responses remains poorly studied. The overlap between these responses is instrumental for the understanding of host evolution in multiparasite environments. We determined the genetic and phenotypic changes underlying adaptation of Drosophila melanogaster to Drosophila C virus (DCV). Within 20 generations, flies selected with DCV showed increased survival after DCV infection, but also after cricket paralysis virus (CrPV) and flock house virus (FHV) infection. Whole-genome sequencing identified two regions of significant differentiation among treatments, from which candidate genes were functionally tested with RNAi. Three genes were validated--pastrel, a known DCV-response gene, and two other loci, Ubc-E2H and CG8492. Knockdown of Ubc-E2H and pastrel also led to increased sensitivity to CrPV, whereas knockdown of CG8492 increased susceptibility to FHV infection. Therefore, Drosophila adaptation to DCV relies on few major genes, each with different cross-resistance properties, conferring host resistance to several parasites.Fundação para a Ciência e a Tecnologia grants: (SFRH/BPD/62964/2009, SFRH/BD/82299/2011, PTDC/SAU-IMU/120673/2010); Austrian Science Fund grants: (P22725, P19467); European Research Council grant: (ArchAdapt); Instituto Gulbenkian de Ciência/Fundação Calouste Gulbenkian; Vetmeduni.info:eu-repo/semantics/publishedVersio

Constraining planet structure and composition from stellar chemistry: trends in different stellar populations

The chemical composition of stars that have orbiting planets provides important clues about the frequency, architecture, and composition of exoplanet systems. We explore the possibility that stars from different galactic populations that have different intrinsic abundance ratios may produce planets with a different overall composition. We compiled abundances for Fe, O, C, Mg, and Si in a large sample of solar neighbourhood stars that belong to different galactic populations. We then used a simple stoichiometric model to predict the expected iron-to-silicate mass fraction and water mass fraction of the planet building blocks, as well as the summed mass percentage of all heavy elements in the disc. Assuming that overall the chemical composition of the planet building blocks will be reflected in the composition of the formed planets, we show that according to our model, discs around stars from different galactic populations, as well as around stars from different regions in the Galaxy, are expected to form rocky planets with significantly different iron-to-silicate mass fractions. The available water mass fraction also changes significantly from one galactic population to another. The results may be used to set constraints for models of planet formation and chemical composition. Furthermore, the results may have impact on our understanding of the frequency of planets in the Galaxy, as well as on the existence of conditions for habitability.Comment: Accepted for publication in Astronomy & Astrophysic

Obtenção de plantas homozigotas derivadas de brs pontal com o transgene derivado de Embrapa 5.1.

O presente trabalho teve como objetivo analisar a transferência do transgene do Embrapa 5.1 para variedades comerciais

Non-sequential double ionization below laser-intensity threshold: Anticorrelation of electrons without excitation of parent ion

Two-electron correlated spectra of non-sequential double ionization below laser-intensity threshold are known to exhibit back-to-back scattering of the electrons, viz., the anticorrelation of the electrons. Currently, the widely accepted interpretation of the anticorrelation is recollision-induced excitation of the ion plus subsequent field ionization of the second electron. We argue that another mechanism, namely simultaneous electron emission, when the time of return of the rescattered electron is equal to the time of liberation of the bounded electron (the ion has no time for excitation), can also explain the anticorrelation of the electrons in the deep below laser-intensity threshold regime. Our conclusion is based on the results of the numerical solution of the time-dependent Schr\"{o}dinger equation for a model system of two one-dimensional electrons as well as an adiabatic analytic model that allows for a closed-form solution.Comment: 6 pages and 3 figure

Descritores botânicos, agronômicos e fenológicos do arroz (Oryza sativa L.).

O presente trabalho teve por objetivo apresentar os descritores morfológicos, agronômicos e fenológicos, bem como suas escalas e critérios utilizados na descrição das linhagens e genótipos de arroz, na Embrapa Arroz e Feijão, e que além de necessários para registro e proteção, são importantes para produtores e técnicos que conduzem campos de produção de sementes e úteis aos analistas que realizam análises de pureza em laboratórios oficiais e particulares de sementes.bitstream/CNPAF-2009-09/28149/1/doc_226.pd