The strength of the analog and Gamow-Teller giant resonances and hindrance of the 2\nu\beta\beta -decay rate

An approach for describing the hindrance of the nuclear 2\nu\beta\beta-decay amplitude is proposed. The approach is based on a new formula obtained by a model-independent transformation of the initial expression for the amplitude. This formula takes explicitly into account the hindrance of the decay-amplitude due to the presence of the collective Gamow-Teller state. Calculations are performed within the simplest version of the approach. Calculated and experimental 2\nu\beta\beta halve-lives are compared for a wide range of nuclei.Comment: 11 pages, 1 tabl

Solbergstrand Experimental Station, Drøbak: Long term effects of oil on marine benthic communities in enclosures. Research Programme

The report outlines the scope of work of the research programme to be performed at Solbergstrand Experimental Station under the sponsorship of British Petroleum. The aim of the programme is to study long term effects of low levels of oil hydrocarbons on littoral rock communities and sublittoral sediment communities kept in large basinsBP Petroleum Development LTD, Norwa

Long term effects of oil on marine benthic communities in enclosures. Littoral rock community project. Progress report No 4. Sublittoral soft bottom project. Progress report No 1

The report presents results achieved during spring/summer 1983 in the subprojects under the research programme "Long term effects of oil on marine benhtic communities in enclosures"BP Petroleum Development Ltd., Norway u/

Long term effects of oil on marine benthic communities in enclosures. Littoral rock community project at Solbergstrand. Progress report No 2, march 1983

The report describes the various research elements of the rocky shore community project at Solbergstrand, and their status until 28 February 1983.BP Petroleum Development Lt

Structural Basis for Enzymatic Excision of N1 Methyladenine and N3 Methylcytosine from DNA

N1 methyladenine m1A and N3 methylcytosine m3C are major toxic and mutagenic lesions induced by alkylation in single stranded DNA. In bacteria and mammals, m1A and m3C were recently shown to be repaired by AlkB mediated oxidative demethylation, a direct DNA damage reversal mechanism. No AlkB gene homologues have been identified in Archaea. We report that m1A and m3C are repaired by the AfAlkA base excision repair glycosylase of Archaeoglobus fulgidus, suggesting a different repair mechanism for these lesions in the third domain of life. In addition, AfAlkA was found to effect a robust excision of 1,N6 ethenoadenine. We present a high resolution crystal structure of AfAlkA, which, together with the characterization of several site directed mutants, forms a molecular rationalization for the newly discovered base excision activit

Efeito da suplementação de lipídios sobre a digestibilidade e os parâmetros da fermentação ruminal em cabras leiteiras Effect of lipid supplementation on digestibility and ruminal metabolism in dairy goats

Avaliou-se o efeito da inclusão de óleo de soja (OS), sais de cálcio de ácidos graxos de cadeia longa (SC) e grão de soja (GS) na dieta sobre o consumo, as digestibilidades total e ruminal dos nutrientes, os parâmetros ruminais e a produção e eficiência de produção de proteína microbiana em cabras. Foram utilizadas oito cabras não-gestantes e não-lactantes, fistuladas no rúmen, distribuídas em delineamento experimental em quadrado latino 4 x 4, com duas repetições. Os tratamentos consistiram de quatro dietas, sendo uma controle (C), isenta de lipídio suplementar, e as demais, adicionadas de um dos suplementos testados, contribuindo com 4,5% de EE suplementar (6,5% na dieta total). A suplementação lipídica não alterou o consumo de MS. Os coeficientes das digestibilidades total e ruminal do EE nas dietas com suplementos lipídicos foram superiores aos da dieta controle. Maior tempo de retenção de partículas sólidas foi obtido com o uso de grão de soja como suplemento. Os tratamentos não influenciaram o pH, a síntese e a eficiência de proteína microbiana, mas reduziram a concentração de amônia no rúmen. A suplementação com lipídios no nível de 4,5% pode ser utilizada de modo eficiente em dietas para caprinos.<br>Eight non-pregnant, non-lactating dairy goats fitted with ruminal cannulas were assigned to two replicated 4 x 4 Latin squares to evaluate the effects of lipid supplementation on intake, total tract and ruminal digestibility of nutrients, ruminal metabolism, and microbial protein synthesis. Animals were fed a control diet (no fat supplementation; 2.0% ether extract) or a diet supplemented (4.5% of added ether extract) with soybean oil (SO), calcium salts of long-chain fatty acids (CS) or whole soybean grain (WS). No significant differences were observed for dry matter intake among diets. Apparent total tract and ruminal digestibilities of ether extract were greater on diets containing fat supplements than on the control diet. The greatest ruminal retention time of particles was observed in the WS diet. Fat supplementation did not affect ruminal pH and microbial protein synthesis and efficiency but reduced the concentration of ruminal ammonia. Based on these results, it is recommended the addition of up to 4.5% of fat in diets of non-lactating dairy goats