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

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

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

Research priorities for next-generation breeding of tropical forages in Brazil.

ABSTRACT: Pasture is the main food source for more than 200 million cattle heads in Brazil. Although Brazilian forage breeding programs have successfully released well-adapted, high-yielding cultivars over the years, the use of genomic tools in these programs is currently limited. These tools are required to tackle the main challenges for tropical forage breeding in Brazil. In this context, this notes lists the main research priorities raised at the workshop ?Breeding Forages in the Genomic Era?, which are necessary to accelerate the use of genomic tools for next-generation breeding of tropical forages and allow breeders to increase genetic gains. Additionally, an online discussion forum (hosted at http://www.cnpgl.embrapa.br/genfor) has been launched to strengthen collaborations among research groups. The research priorities and more synergistic collaborations will assist researchers and decision-makers in delivering a sustainable increase in production of animal products, especially beef and milk, which are required to feed a rising world population

Research priorities for next-generation breeding of tropical forages in Brazil.

ABSTRACT: Pasture is the main food source for more than 200 million cattle heads in Brazil. Although Brazilian forage breeding programs have successfully released well-adapted, high-yielding cultivars over the years, the use of genomic tools in these programs is currently limited. These tools are required to tackle the main challenges for tropical forage breeding in Brazil. In this context, this notes lists the main research priorities raised at the workshop “Breeding Forages in the Genomic Era”, which are necessary to accelerate the use of genomic tools for next-generation breeding of tropical forages and allow breeders to increase genetic gains. Additionally, an online discussion forum (hosted at http://www.cnpgl.embrapa.br/genfor) has been launched to strengthen collaborations among research groups. The research priorities and more synergistic collaborations will assist researchers and decision-makers in delivering a sustainable increase in production of animal products, especially beef and milk, which are required to feed a rising world population

Succinate causes pathological cardiomyocyte hypertrophy through GPR91 activation

Background\ud Succinate is an intermediate of the citric acid cycle as well as an extracellular circulating molecule, whose receptor, G protein-coupled receptor-91 (GPR91), was recently identified and characterized in several tissues, including heart. Because some pathological conditions such as ischemia increase succinate blood levels, we investigated the role of this metabolite during a heart ischemic event, using human and rodent models.\ud \ud \ud Results\ud We found that succinate causes cardiac hypertrophy in a GPR91 dependent manner. GPR91 activation triggers the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), the expression of calcium/calmodulin dependent protein kinase IIδ (CaMKIIδ) and the translocation of histone deacetylase 5 (HDAC5) into the cytoplasm, which are hypertrophic-signaling events. Furthermore, we found that serum levels of succinate are increased in patients with cardiac hypertrophy associated with acute and chronic ischemic diseases.\ud \ud \ud Conclusions\ud These results show for the first time that succinate plays an important role in cardiomyocyte hypertrophy through GPR91 activation, and extend our understanding of how ischemia can induce hypertrophic cardiomyopathy.CAPESFAPEMIG (Pronex)INCT- Carbon NanotubesCNPqHHM

Measurement of χ c1 and χ c2 production with s√ = 7 TeV pp collisions at ATLAS

The prompt and non-prompt production cross-sections for the χ c1 and χ c2 charmonium states are measured in pp collisions at s√ = 7 TeV with the ATLAS detector at the LHC using 4.5 fb−1 of integrated luminosity. The χ c states are reconstructed through the radiative decay χ c → J/ψγ (with J/ψ → μ + μ −) where photons are reconstructed from γ → e + e − conversions. The production rate of the χ c2 state relative to the χ c1 state is measured for prompt and non-prompt χ c as a function of J/ψ transverse momentum. The prompt χ c cross-sections are combined with existing measurements of prompt J/ψ production to derive the fraction of prompt J/ψ produced in feed-down from χ c decays. The fractions of χ c1 and χ c2 produced in b-hadron decays are also measured