Genetic gain in an improvement program of irrigated rice in Minas Gerais.

An evaluation of the genetic improvement programme of irrigated rice of Minas Gerais (Brazil) estimated the genetic gain obtained in the 90s. Grain yield data of the advanced comparative trials of cultivars and lines of continuously flooded rice, conducted from 1990-91 to 2000-01, were used. The estimate of the genetic gain was obtained by the methodology of the adjusted means proposed by Breseghello (1998). The mean annual genetic gain in the 90s was 42.45+or-17.89 kg ha-1 (0.7% per year). The improvement programme proved auspicious for the development of lines that outmatched the controls. The mean of the cultivars released in the 90s did however not outstrip the mean of the elite lines, which were the genotypes with the highest means in this study and will be further evaluated in the ongoing programme

Estimativa de custo de produção de soja, nos sistemas plantio direto e convencional, safra 1999/2000.

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Estimativa de custo de produção de algodão, no sistema plantio convencional, safra 1999/2000.

bitstream/item/39711/1/COT-06-1999.pd

Chemical abundances for the transiting planet host stars OGLE-TR-10, 56, 111, 113, 132 and TrES-1. Abundances in different galactic populations

We used the UVES spectrograph (VLT-UT2 telescope) to obtain high-resolution spectra of 6 stars hosting transiting planets, namely for OGLE-TR-10, 56, 111, 113, 132 and TrES-1. The spectra are now used to derive and discuss the chemical abundances for C, O, Na, Mg, Al, Si, S, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Cu and Zn. Abundances were derived in LTE, using 1-D plane-parallel Kurucz model atmospheres. For S, Zn and Cu we used a spectral synthesis procedure, while for the remaining cases the abundances were derived from measurements of line-equivalent widths. The resulting abundances are compared with those found for stars in the solar neighborhood. Distances and galactic coordinates are estimated for the stars. We conclude that besides being particularly metal-rich, with small possible exceptions OGLE-TR-10, 56, 111, 113, 132 and TrES-1 are chemically undistinguishable from the field (thin disk) stars regarding their [X/Fe] abundances. This is particularly relevant for the most distant of the targets, located at up to ~2 Kpc from the Sun. We also did not find any correlation between the abundances and the condensation temperature of the elements, an evidence that strong accretion of planetary-like material, tentatively connected to planetary migration, did not occur.Comment: Accepted for publication in Astronomy & Astrophysics (June 2006

Avaliação dos impactos ambientais e econômicos do controle químico do percevejo-barriga-verde (Dichelops melacanthus) em trigo e milho safrinha.

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Estabilidade e adaptabilidade de arroz de terras altas sob sistema de plantio convencional e direto.

O objetivo do trabalho foi: a) Avaliar linhagens e cultivares de arroz de terras altas em dois sistemas de plantio: direto e convencional; b) Estudar a interação entre linhagens/cultivares de arroz x ambientes; c) Avaliar a adaptabilidade e estabilidade das linhagens e cultivares de arroz testadas nos sistemas de plantio direto e convencional

Relação entre o escurecimento dos grãos de feijão carioca e o tempo de cocção.

Objetivo deste trabalho foi verificar a associação entre o retardamento do escurecimento dos grãos de feijão carioca e o seu tempo de cocção.CONAFE

Nambu monopoles interacting with lattice defects in two-dimensional artificial square spin ice

The interactions between an excitation (similar to a pair of Nambu monopoles) and a lattice defect are studied in an artificial two-dimensional square spin ice. This is done by considering a square array of islands containing only one island different from all others. This difference is incorporated in the magnetic moment (spin) of the "imperfect" island and several cases are studied, including the special situation in which this distinct spin is zero (vacancy). We have shown that the two extreme points of a malformed island behave like two opposite magnetic charges. Then, the effective interaction between a pair of Nambu monopoles with the deformed island is a problem involving four magnetic charges (two pairs of opposite poles) and a string. We also sketch the configuration of the field lines of these four charges to confirm this picture. The influence of the string on this interaction decays rapidly with the string distance from the defect.Comment: 7 pages, 13 figure