Relativistic approach to positronium levels in a strong magnetic field

We have investigated the bound states of an electron and positron in superstrong magnetic fields typical for neutron stars. The complete relativistic problem of positronium in a strong magnetic field has not been succesfully solved up to now. In particular, we have studied the positronium when it moves relativistically across the magnetic field. A number of problems which deal with the pulsar magnetosphere, as well as the evolution of protoneutron stars, could be considered as a field for application

Defect localization based on modulated photothermal local approach

A new method dedicated to macroscopic-like defect localization in composite materials is presented in this paper. The proposed method is based on non intrusive measurements of the sample temperature resulting from a local periodic low energy heating. In such an approach, the low temperature increases of the investigated material avoid damages which can occur with usual flash techniques. Since thermal waves propagation is modified due to the heterogeneity induced by the defect, analysis of both modulus and phase lag spatial distributions provides relevant knowledge. Up to now, macroscopic-like defect detection based on local periodic heating has not been widely investigated. Thus, differences between the global approach and the local approach have to be pointed out in order to verify the local method’s attractiveness. A mathematical model based on complex temperature is developed and provides a relevant predictive tool. In several configurations interest of local periodic heating is highlighted. For example, while several defects are included in the sample, the method capability to distinguish one from each other is shown considering a scanning approach. In order to validate these results, an experimental device has been developed. Several non destructive inspections are performed and defect detection is achieved using an infra-red camera providing observations of the sample surface.

Pinworms of the red howler monkey (Alouatta seniculus) in Colombia. Gathering the pieces of the pinworm-primate puzzle

Pinworms of primates are believed to be highly host specific parasites, forming co-evolutionary associations with their hosts. In order to assess the strength and reach of such evolutionary links, we need to have a broad understanding of the pinworm diversity associated with primates. Here, we employed an integrative taxonomic approach to assess pinworm diversity in red howler monkeys in Colombia. Molecular and morphological evidence validate the presence of at least four different species of Trypanoxyuris occurring in red howler monkeys: T. minutus, a widely distributed species, and three new species, T. seunimiii n. sp., T. kemuimae n. sp. and T. kotudoi n. sp. The mitochondrial COI gene and the 28S ribosomal gene were used for phylogenetic assessments through Bayesian inference. The three new species were morphologically distinct and formed reciprocally monophyletic lineages. Further molecular lineage subdivision in T. minutus and T. kotudoi n. sp. without morphological correspondence, suggests the potential scenario for the existence of cryptic species. Phylogenetic relationships imply that the different species of Trypanoxyuris occurring in each howler monkey species were acquired through independent colonization events. On-going efforts to uncover pinworm diversity will allow us to test the degree of host specificity and the co-phylogenetic hypothesis, as well as to further unravel the primate-pinworm evolutionary history puzzle

Neutrino-pair radiation form neutron star crusts: Collective effects

We present a method to calculate $\nu \bar{\nu}$ energy losses from neutron star crusts, which automatically takes into account for collective effects, and allows to calculate the total emissivity without a separate consideration of particular processes. We show that the formula we obtain describe the known results for the emissivity due to plasmon decay and Bremsstrahlung from degenerate electrons, when one of this processes dominates. In the case of low temperatures, our formula gives a suppression of the electron vector weak-current contribution to $\nu \bar{\nu}$ Bremsstrahlung, due to the collective effects discussed in this paper

Avaliação geral, resultados e perspectivas do uso de agricultura de precisão em culturas perenes.

O Projeto Componente 4 da Rede de Agricultura de Precisão, intitulado ?Caracterização, manejo e monitoramento de atributos do solo e da planta em sistemas de produção de plantas perenes e semi-perenes? constitui-se de 7 planos de ação que contam com a participação interativa de várias unidades da Embrapa, instituições de pesquisa, universidades e parceiros da setor produtivo agrícola. A estratégia de trabalho baseia-se na implantação de unidades pilotos (UPs) de pesquisa em agricultura de precisão em diferentes regiões do Brasil, onde deverão ser analisadas diversas possibilidades de uso de procedimentos e ferramentas inerentes à agricultura de precisão (AP) em cultivos de videira, macieira, pessegueiro, citrus, espécies florestais, cana de açúcar e pastagem. A análise da variabilidade espacial e temporal de atributos do solo e da planta deverá ser utilizada na definição de zonas homogêneas, para um manejo mais eficiente dos sistemas de produção, quanto ao uso de espécies vegetais, água, solo, fertilizantes e defensivos agrícolas. Pretende-se também auxiliar o produtor quanto ao gerenciamento das informações do campo por meio de ferramentas e procedimentos utilizados em AP. Ainda, haverá a incorporação de profissionais à prática de AP, bem como a realização de pesquisas em sistemas de produção não abordados anteriormente quanto à AP no Brasil. Os impactos potenciais são o fornecimento, disseminação e transferência de procedimentos e ferramentas analíticas para adoção da agricultura de precisão em sistemas de produção de espécies perenes e semi-perenes, sendo que muitos deles poderão ser diretamente aplicados ou adaptados para outros sistemas de produção de culturas não contemplados nesse projeto componente