Identificação de seqüências expressas etiquetadas (ESTs) envolvidas na interação de arroz e do fungo causador da brusone (Magnaphorte grisea).

Considerando que um dos requisitos primordiais para o uso das novas ferramentas biotecnológicas é a identificação de genes, duas bibliotecas subtrativas foram construídas utilizando-se mRNA isolado de folhas de arroz infectadas por M. grisea, com o objetivo de construir um banco de ESTs visando analisar a expressão de genes induzidos ou suprimidos durante a interação patógeno-hospedeiro. Ate o presente momento, 1232 ESTs foram geradas e a análise das mesmas, utilizando métodos computacionais, encontra-se em andamento. Adicionalmente, a fornecer informações do modelo de expressão de genes de defesa do arroz, este estudo disponibilizará genes para estudos de genômica funcional e desta maneira poderá elucidar o mecanismo de resistência da planta a este fungo.Coordenação geral: Maria Fátima Grossi de Sá

Avaliação de genótipos de Brachiaria quanto à resistência às cigarrinhas-das-pastagens (Hemiptera: Cercopidae).

Comissão organizadora: Grácia Maria Soares Rosinha, Alexandra Rocha de Oliveir, Rodrigo Carvalho Alva

Nitrogen pools in tropical plantations of N2-fixing and non-N2-fixing legume trees under different tree stand densities.

We investigated the nitrogen pools in monocultures of legume species widely used in reforestation in Brazil that have contrasting growth and nitrogen acquisition strategies. The plantations were established with the slow-growing and N2-fixing tree Anadenanthera peregrina var. peregrina, and the fast-growing and non-fixing tree Schizolobium parahyba var. amazonicum. The measurements of N pools in the tree biomass and the soil followed standard methods and were carried out on 54 experimental plots. The N2 fixation pools were evaluated by abundance natural of 15N and the N accretion methods. The soil N content was of similar magnitude between species and stand densities. The species showed similar amounts of N in the biomass, but divergent patterns of N accumulation, as well as the 15N signature on the leaves. S. parahyba accumulated most N in the stem, while A. peregrina accumulated N in the roots and leaves. However, the N accumulation in biomass of A. peregrina stand was less constrained by environment than in S. parahyba stands. The percentage of N derived from N2 fixation in A. peregrina stands decreased with the increase of stand density. The biological N2 fixation estimates depended on the method and the response of tree species to environment

Levantamento expedito dos solos das reservas florestais de Linhares e Sooretama no Estado do Espírito Santo.

O presente trabalho teve como objetivo fornecer subsídios para melhor utilização das Reservas Florestais de Linhares e de Sooretama. Como o manejo florestal não exige mapas de levantamento de solos detalhado, elaborou-se nestas áreas, levantamento expedito dos solos. Este boletim técnico foi realizado para atender os professores e pesquisadores da Universidade Federal do Rio de Janeiro (UFRJ) - Projeto Biodiversidade, além de técnicos de outras entidades. A metodologia usada foi a desenvolvida pela Embrapa Solos. Foram usados como material básico, cartas do IBGE na escala 1:100.000. O mapa final é constituído por 12 unidades de mapeamento, com as seguintes classes de solos: LATOSSOLO VERMELHO, ARGISSOLO AMARELO, ESPODOSSOLOS e NEOSSOLOSbitstream/item/89239/1/bpd49-2004-sooretama.pd

CMB Polarization and Theories of Gravitation with Massive Gravitons

We study in this paper three different theories of gravitation with massive gravitons - the modified Fierz-Pauli (FP) model, Massive Gravity and the bimetric theory proposed by Visser - in linear perturbation theory around a Minkowski and a flat FRW background. For the TT tensor perturbations we show that the three theories give rise to the same dynamical equations and to the same form of the Boltzmann equations for the radiative transfer in General Relativity (GR). We then analyze vector perturbations in these theories and show that they do not give the same results as in the previous case. We first show that vector perturbations in Massive Gravity present the same form as found in General Relativity, whereas in the modified FP theory the vector gravitational-wave (GW) polarization modes ($\Psi_{3}$ amplitudes in the Newman-Penrose (NP) formalism) do not decay too fast as it happens in the former case. Rather, we show that such $\Psi_{3}$ polarization modes give rise to an unusual vector Sachs-Wolfe effect, leaving a signature in the quadrupole form $Y_{2,\pm 1}(\theta,\varphi)$ on the CMB polarization. We then derive the details for the Thomson scattering of CMB photons for these $\Psi_{3}$ modes, and then construct the correspondent Boltzmann equations. Based upon these results we then qualitatively show that $\Psi_{3}$-mode vector signatures - if they do exist - could clearly be distinguished on the CMB polarization from the usual $\Psi_4$ tensor modes.Comment: To appear in Classical and Quantum Gravit