1,174 research outputs found
Efeito do silício em alguns componentes de resistência a antracnose em linhagens de sorgo.
xEdição dos Resumos do XL Congresso Brasileiro de Fitopatologia, Maringá, PR, ago. 2007
Respostas correlacionadas diretas e indiretas envolvendo cinco caracteres do milho (Zea mays L.) avaliados em solos sob cerrado e fertil.
Melhoramento molecular como ferramenta para aumentar a qualidade das forrageiras tropicais Brachiaria brizantha e Panicum maximum.
As pastagens constituem a principal fonte de alimentação dos bovinos no Brasil. O desempenho desses animais em pastagens depende do potencial genético do animal, da disponibilidade de forragem na pastagem, da qualidade desta forragem e do consumo da mesma por parte do animal (CÓSER et al., 2008). Cabe ressaltar que em criações que visam produção de carne, o acréscimo no desempenho dos bovinos resulta em menor permanência do animal no sistema, reduzindo a produção de metano (CH4) durante o seu ciclo de vida, contribuindo para mitigar a emissão de gases de efeito estufa (GEE). Dentre as principais espécies utilizadas nas pastagens brasileiras estão Brachiaria brizantha e Panicum maximum, gramíneas tropicais (C4), de origem africana, amplamente adaptadas às condições edafo-climáticas do País. Elas apresentam elevada taxa de crescimento e produção de matéria seca, em virtude da maior eficiência na fixação de carbono (C4) em relação às gramíneas temperadas (C3), porém a sua qualidade (proteína e digestibilidade) é, em geral, inferior a das gramíneas temperadas (C3), cuja degradação ruminal é mais rápida devido à parede celular menos espessa, ou seja, com menor teor de compostos indigeríveis, como a lignina (CABRAL et al., 2004). Tendo em vista a complexidade genética de B. brizantha e P. maximum (poliplóides e apomíticas) novas técnicas genômicas e da biotecnologia moderna (transgenia) apresentam-se como abordagens promissoras para obtenção de novas cultivares com melhor qualidade. Para viabilizar esta abordagem sem o pagamento de taxas de licenciamento e ?royalties? há necessidade de se buscar genes e promotores que possam ser utilizados em construções gênicas para obtenção dessas gramíneas forrageiras tropicais geneticamente melhoradasPoster 058
Influência da densidade de plantio e da adubação, nitrogenada em cobertura em genótipos de milho, para fins de melhoramento.
Desenvolvimento vegetativo de Manihot esculenta Cranz em reposta à adubação fosfatada e inoculação micorrízica.
Vortex state in a doped Mott insulator
We analyze the recent vortex core spectroscopy experiments in cuprate
superconductor and discuss what can be learned from them about the nature of
the ground state in these compounds. We argue that the data are inconsistent
with the assumption of a simple metallic ground state and exhibit
characteristics of a doped Mott insulator. A theory for a vortex core in such a
doped Mott insulator is developed based on the U(1) gauge field slave boson
model and is shown to exhibit properties qualitatively consistent with the
experimental data.Comment: 11 pages REVTeX, 3 ps figures; version to appear in PR
Network model of immune responses reveals key effectors to single and co-infection dynamics by a respiratory bacterium and a gastrointestinal helminth
Co-infections alter the host immune response but how the systemic and local processes at the site of infection interact is still unclear. The majority of studies on co-infections concentrate on one of the infecting species, an immune function or group of cells and often focus on the initial phase of the infection. Here, we used a combination of experiments and mathematical modelling to investigate the network of immune responses against single and co-infections with the respiratory bacterium Bordetella bronchiseptica and the gastrointestinal helminth Trichostrongylus retortaeformis. Our goal was to identify representative mediators and functions that could capture the essence of the host immune response as a whole, and to assess how their relative contribution dynamically changed over time and between single and co-infected individuals. Network-based discrete dynamic models of single infections were built using current knowledge of bacterial and helminth immunology; the two single infection models were combined into a co-infection model that was then verified by our empirical findings. Simulations showed that a T helper cell mediated antibody and neutrophil response led to phagocytosis and clearance of B. bronchiseptica from the lungs. This was consistent in single and co-infection with no significant delay induced by the helminth. In contrast, T. retortaeformis intensity decreased faster when co-infected with the bacterium. Simulations suggested that the robust recruitment of neutrophils in the co-infection, added to the activation of IgG and eosinophil driven reduction of larvae, which also played an important role in single infection, contributed to this fast clearance. Perturbation analysis of the models, through the knockout of individual nodes (immune cells), identified the cells critical to parasite persistence and clearance both in single and co-infections. Our integrated approach captured the within-host immuno-dynamics of bacteria-helminth infection and identified key components that can be crucial for explaining individual variability between single and co-infections in natural populations
Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector
The inclusive and dijet production cross-sections have been measured for jets
containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass
energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The
measurements use data corresponding to an integrated luminosity of 34 pb^-1.
The b-jets are identified using either a lifetime-based method, where secondary
decay vertices of b-hadrons in jets are reconstructed using information from
the tracking detectors, or a muon-based method where the presence of a muon is
used to identify semileptonic decays of b-hadrons inside jets. The inclusive
b-jet cross-section is measured as a function of transverse momentum in the
range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet
cross-section is measured as a function of the dijet invariant mass in the
range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets
and the angular variable chi in two dijet mass regions. The results are
compared with next-to-leading-order QCD predictions. Good agreement is observed
between the measured cross-sections and the predictions obtained using POWHEG +
Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet
cross-section. However, it does not reproduce the measured inclusive
cross-section well, particularly for central b-jets with large transverse
momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final
version published in European Physical Journal
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