Digestibilidade de dietas constantes de feno de capim mandante e milho, suplementadas com farelos de algodão e de mamona desintoxicada.

Foi realizado um estudo comparativo entre os farelos de algodão e de mamona desintoxicada, através de ensaio de digestibilidade com ovinos adultos, como suplementos proteícos de uma dieta básica constante de capim mandante e milho moido (grão)

Extra-matrix Mg\u3csup\u3e2+\u3c/sup\u3e Limits Ca\u3csup\u3e2+\u3c/sup\u3e Uptake and Modulates Ca\u3csup\u3e2+\u3c/sup\u3e Uptake-independent Respiration and Redox State in Cardiac Isolated Mitochondria

Cardiac mitochondrial matrix (m) free Ca2+ ([Ca2+]m) increases primarily by Ca2+ uptake through the Ca2+ uniporter (CU). Ca2+ uptake via the CU is attenuated by extra-matrix (e) Mg2+ ([Mg2+]e). How [Ca2+]m is dynamically modulated by interacting physiological levels of [Ca2+]e and [Mg2+]e and how this interaction alters bioenergetics are not well understood. We postulated that as [Mg2+]e modulates Ca2+ uptake via the CU, it also alters bioenergetics in a matrix Ca2+–induced and matrix Ca2+–independent manner. To test this, we measured changes in [Ca2+]e, [Ca2+]m, [Mg2+]e and [Mg2+]m spectrofluorometrically in guinea pig cardiac mitochondria in response to added CaCl2 (0–0.6 mM; 1 mM EGTA buffer) with/without added MgCl2 (0–2 mM). In parallel, we assessed effects of added CaCl2 and MgCl2 on NADH, membrane potential (ΔΨm), and respiration. We found that \u3e0.125 mM MgCl2 significantly attenuated CU-mediated Ca2+ uptake and [Ca2+]m. Incremental [Mg2+]e did not reduce initial Ca2+uptake but attenuated the subsequent slower Ca2+ uptake, so that [Ca2+]m remained unaltered over time. Adding CaCl2 without MgCl2 to attain a [Ca2+]m from 46 to 221 nM enhanced state 3 NADH oxidation and increased respiration by 15 %; up to 868 nM [Ca2+]m did not additionally enhance NADH oxidation or respiration. Adding MgCl2 did not increase [Mg2+]m but it altered bioenergetics by its direct effect to decrease Ca2+ uptake. However, at a given [Ca2+]m, state 3 respiration was incrementally attenuated, and state 4 respiration enhanced, by higher [Mg2+]e. Thus, [Mg2+]e without a change in [Mg2+]m can modulate bioenergetics independently of CU-mediated Ca2+ transport

Promoção de eventos culturais na Biblioteca da Embrapa Florestas: responsabilidade social e cultural.

Apresenta uma reflexão sobre a responsabilidade e compromisso social das bibliotecas e descreve ações desenvolvidas por uma biblioteca especializada na área de pesquisa com o objetivo de promover a biblioteca, incentivar atividades culturais, bem como de sociabilizar a mesma na empresa

Desempenho agronômico de sorgo sacarino no agreste alagoano em função da densidade e espaçamento de plantio.

A cana-de-açúcar é colhida em Alagoas, em geral, entre os meses de setembro a março. No restante do ano ocorre a entressafra com a paralisação da moagem. Uma alternativa para aumentar a produção de bioenergia do Estado seria o prolongamento da safra com o uso de culturas com potencial para a produção de etanol durante o período de entressafra e uma das alternativas que poderiam ser utilizadas é o sorgo sacarino. O objetivo do trabalho foi avaliar a influência de diferentes espaçamentos e densidades de plantio de sorgo sacarino cultivado em usinas sucroalcooleiras na região Agreste do Estado de Alagoas. Foram avaliados três espaçamentos entre linhas (0,5m, 0,7m e 0,9m) e cinco densidades de plantio (100, 120, 140, 160 e 180 mil plantas.ha-1) no delineamento em parcela subdividida com três repetições. As densidades de plantio não afetaram as características avaliadas. O espaçamento 0,5m proporcionou maior produtividade de massa verde total, massa verde e seca de colmo e produtividade de panículas quando comparado ao espaçamento de 0,9m e maior produtividade de massa verde total em relação ao espaçamento 0,7m

Theory of Light Emission in Sonoluminescence as Thermal Radiation

Based on the model proposed by Hilgenfeldt {\it at al.} [Nature {\bf 398}, 401 (1999)], we present here a comprehensive theory of thermal radiation in single-bubble sonoluminescence (SBSL). We first invoke the generalized Kirchhoff's law to obtain the thermal emissivity from the absorption cross-section of a multilayered sphere (MLS). A sonoluminescing bubble, whose internal structure is determined from hydrodynamic simulations, is then modelled as a MLS and in turn the thermal radiation is evaluated. Numerical results obtained from simulations for argon bubbles show that our theory successfully captures the major features observed in SBSL experiments.Comment: 17 pages, 20 figure

Ecology and diversity of freshwater shrimps in Banco National Park, Côte d’Ivoire (Banco River Basin)

Shrimps are an important component of river invertebrate assemblages in tropical freshwater where they are a controlling group in food webs. In order to determine shrimp diversity in the Banco Basin (Côte d’Ivoire, West Africa) and examine whether the patterns of species distribution were related to environmental conditions, six sites were monitored. Sampling was conducted in 2008 during February, May, September and November using a long-handled net (25-cm diameter, 2-mm mesh). For each site, we measured environmental variables (conductivity, pH, water temperature, dissolved oxygen, turbidity, current speed, and water depth and width). Three shrimp species, Macrobrachium thysi (Powell 1980), Macrobrachium dux (Lenz 1910) and Desmocaris trispinosa (Aurivillius 1898) were identified. D. trispinosa was the largest distributed (more than 50% of occurrence) and the most abundant (67% of total number of specimens caught). It was followed by M. thysi with 47% and 32% of occurrence and abundance, respectively. Canonical correspondence analysis (CCA) showed a spatial distribution of the shrimp community, significantly influenced by width, depth, conductivity, type of substrate, turbidity and dissolved oxygen. Due to the fact that the Banco River hosts an endemic species in Côte d’Ivoire (Macrobrachium thysi), the conservation of integrity of this basin was recommended