A Compound model for the origin of Earth's water

One of the most important subjects of debate in the formation of the solar system is the origin of Earth's water. Comets have long been considered as the most likely source of the delivery of water to Earth. However, elemental and isotopic arguments suggest a very small contribution from these objects. Other sources have also been proposed, among which, local adsorption of water vapor onto dust grains in the primordial nebula and delivery through planetesimals and planetary embryos have become more prominent. However, no sole source of water provides a satisfactory explanation for Earth's water as a whole. In view of that, using numerical simulations, we have developed a compound model incorporating both the principal endogenous and exogenous theories, and investigating their implications for terrestrial planet formation and water-delivery. Comets are also considered in the final analysis, as it is likely that at least some of Earth's water has cometary origin. We analyze our results comparing two different water distribution models, and complement our study using D/H ratio, finding possible relative contributions from each source, focusing on planets formed in the habitable zone. We find that the compound model play an important role by showing more advantage in the amount and time of water-delivery in Earth-like planets.Comment: Accepted for publication in The Astrophysical Journa

Cultivo in vitro de embriões zigóticos de pimenta-do-reino em meio contendo antibióticos.

A pimenteira-do-reino foi introduzida no Brasil no século XVII, assumindo cultivo comercial somente a partir da década de 30 quando introduzida no Pará por imigrantes japoneses. Objetivou-se avaliar a oxidação de embriões zigóticos de pimenta-do-reino em meio de cultura suplementado com diferentes antibióticos (Higromicina e Canamicina). Foram coletados frutos maduros da cultivar Bragantina, provenientes de matrizes do BAG da pimenteira-do-reino da Embrapa Amazônia Oriental para retirada dos embriões zigóticos. Nas diferentes concentrações de antibióticos, os embriões zigóticos respondem diferentemente quanto aos níveis de oxidação, evidenciando maior oxidação com o aumento da concentração desse reagente

Yield, nutritional status and soil chemical properties as response to cattle manure, reactive natural rock phosphate and biotite schist in Massai grass.

In animal production, grasses planted in the pasture lands have especial value to improve aggregate value of products. This paper evaluates the effects of applying cattle manure, reactive natural phosphate and biotite schist on soil fertility, yield and nutritional content of Megathyrsus spp. cv. Massai. The experiment was conducted under field conditions, in a dystroferric Red Latosol (Oxisol). The experimental design was randomized blocks with the treatments confounding, with one replicate. The treatments consisted of three rates of natural reactive rock phosphate from Algeria - Djebel-Onk (0, 100 and 200 kg ha-1 of P2O5), three biotite schist rates (0, 150 and 300 kg ha-1 of K2O) and three cattle manure rates (0, 20 and 40 Mg ha-1). The application of reactive natural rock phosphate increased dry matter yield (DMY), however, this effect was not observed for cattle manure and biotite schist. The foliar contents of N, K and Mg (cattle manure), P and B (natural rock phosphate) and K (biotite schist) were significantly influenced by the treatments. The same effect was found forP levels in soil, dry matter of the aerial part, Mg and B content in the dry matter

Detection

This review on second- and third-generation multidetectors devoted to heavy-ion collisions aims to cover the last twenty years. The presented list of devices is not exhaustive but regroups most of the techniques used during this period for nuclear reactions at intermediate energy (≈ 10A MeV to 1A GeV), both for charged-particle and neutron detection. The main part will be devoted to 4π multidetectors, projectile decay fragmentation, high-resolution magnetic spectrometers, auxiliary detectors and neutron detection. The last part will present the progress in electronics and detection in view of the construction of future-generation detectors

Production, nutritional status and chemical properties of soils with addition of cattle manure, reactive natural phosphate and biotite schist in Massai cultivar.

The objective of this work was to evaluate the effects of cattle manure, reactive natural phosphate and biotite schist on the soil fertility, yield and nutritional status of Megathyrsus spp. cv. Massai. The experiment was conducted under field conditions, in a dystrophic Red Yellow Latosol (Oxisol). It was used a randomized block experimental design with the following treatments: three natural reactive rock phosphate from Algeria (Djebel-Onk) doses (0, 100 and 200 kg ha-1 of P2O5), three biotite schist doses (0, 150 and 300 kg ha-1 of K2O) and three cattle manure doses (0, 20 and 40 t ha-1). The application of natural phosphate increased dry matter yield, however, application of cattle manure and biotite schist did not influence this variable. Foliar levels of nitrogen, potassium and magnesium (cattle manure), phosphorous and boron (natural rock phosphate) and potassium (biotite schist) were influenced by the applied fertilizer doses. Only the levels of phosphorous in the soil and in the plant and levels of magnesium and boron in the plant show interaction with dry matter yield of Massai cultivar

Quadratic Effective Action for QED in D=2,3 Dimensions

We calculate the effective action for Quantum Electrodynamics (QED) in D=2,3 dimensions at the quadratic approximation in the gauge fields. We analyse the analytic structure of the corresponding nonlocal boson propagators nonperturbatively in k/m. In two dimensions for any nonzero fermion mass, we end up with one massless pole for the gauge boson . We also calculate in D=2 the effective potential between two static charges separated by a distance L and find it to be a linearly increasing function of L in agreement with the bosonized theory (massive Sine-Gordon model). In three dimensions we find nonperturbatively in k/m one massive pole in the effective bosonic action leading to screening. Fitting the numerical results we derive a simple expression for the functional dependence of the boson mass upon the dimensionless parameter e^{2}/m .Comment: 10 pages, 2 figure

Comparação de métodos de estimativa da evapotranspiração de referência para Esperantina - PI.

O objetivo do trabalho foi comparar e avaliar o desempenho de métodos de estimativa de evapotranspiração de referência em relação ao método Penman-Monteith/FAO, visando proporcionar à região de Esperantina-PI, informações básicas para a estimativa da ETo. Os dados meteorológicos foram obtidos na estação meteorológica convencional do INMET, entre o período de 01/01/2008 à 31/12/2012 ,especificamente da unidade situada em Esperantina, PI, com latitude 03º54'06", longitude 42º14'01" W e altitude media de 59 m. Os dados obtidos foram divididos em dois períodos distintos: período seco (15/07) e período chuvoso (15/02). Os métodos de estimativa da evapotranspiração de referência utilizados foram os de Makking (MK), Jensen-Haise (JH), Priestley-Taylor (PT), Hargreaves-Samani (HS), Camargo (CA) e Ivanov (IVN), descritos em comparação ao método de Penman-Monteih (PM). Foram realizados cálculos de erro padrão de estimativa, dos coeficientes de determinação, correlação, o índice de Willmott e o coeficiente de desempenho entre os métodos avaliados e o padrão. Os métodos de Jensen-Haise, Priestley-Taylor e Makking apresentaram desempenho ótimo para os dois períodos estudados, quando comparados ao de Penman- Monteith, demonstrando que estes podem ser utilizados como uma alternativa para a estimativa da ETo no município de Esperantina-PI.CONBEA 2014

Variabilidade patogênica entre isolados de phaeoisariopsis griseola.

O feijoeiro comum (Phaeolus vulgaris L.) é hospedeiro de vários patógenos. Entre os patógenos que afetam esta cultura destaca-se o fungo Phaeoisariopsis griseola (Sacc.) Ferraris, agente causal da mancha angular. Esta doença pode proporcionar perdas de até 80% na produção..

Reaction mechanisms for weakly-bound, stable nuclei and unstable, halo nuclei on medium-mass targets

An experimental overview of reactions induced by the stable, but weakly-bound nuclei 6Li, 7Li and 9Be, and by the exotic, halo nuclei 6He, 8B, 11Be and 17F on medium-mass targets, such as 58Ni, 59Co or 64Zn, is presented. Existing data on elastic scattering, total reaction cross sections, fusion processes, breakup and transfer channels are discussed in the framework of a CDCC approach taking into account the breakup degree of freedom.Comment: 7 pages, 6 figures, Invited Talk given by C. Beck to the 10th International Conference on Nucleus-Nucleus Collisions, August 16-21, 2009 Beijing, China; Paper submitted to the NN2009 Proceedings, Nuclear Physics A (to be published