Some remarks on the attractor behaviour in ELKO cosmology

Recent results on the dynamical stability of a system involving the interaction of the ELKO spinor field with standard matter in the universe have been reanalysed, and the conclusion is that such system does not exhibit isolated stable points that could alleviate the cosmic coincidence problem. When a constant parameter $\delta$ related to the potential of the ELKO field is introduced in the system however, stable fixed points are found for some specific types of interaction between the ELKO field and matter. Although the parameter $\delta$ is related to an unknown potential, in order to satisfy the stability conditions and also that the fixed points are real, the range of the constant parameter $\delta$ can be constrained for the present time and the coincidence problem can be alleviated for some specific interactions. Such restriction on the ELKO potential opens possibility to apply the ELKO field as a candidate to dark energy in the universe, and so explain the present phase of acceleration of the universe through the decay of the ELKO field into matter.Comment: 17 pages, section III with minor changes and section IV rewritten with a new analysi

Further insights into the role of methional and phenylacetaldehyde in lager beer flavor stability

This work attempts to measure the importance of methional and phenylacetaldehyde on the flavor stability of beer, as direct participants or as indicators of aroma deterioration. A trained sensory panel identified the most important descriptors related to the typical aroma of aged beer: “malty”, “honeylike”, “cooked potato”, and “metallic”. By GC-olfactometry analysis, six aromatic zones related to the selected descriptors were highlighted, and by using GC-MS techniques it was possible to identify methional and phenylacetaldehyde as being responsible for two odor zones. The quantification of these molecules in samples submitted to forced aging treatments showed that the levels of methional and phenylacetaldehyde are dependent on the temperature of storage. Normal aged beers were also analyzed, and it was observed that these compounds accumulate with time of storage. Furthermore, these molecules were negatively correlated with the aroma quality of beer as evaluated by a sensorial panel. To validate the sensory impact of these substances, a fresh beer was spiked with these molecules and also with trans-2-nonenal, singly and in combination, and the similarity value between samples and the aged beer was then determined. The highest value from the similarity tests was 72% when the three compounds were added simultaneously. The combination of the two Strecker aldehydes increases by 54% the degree of similarity, indicating the key role played by these molecules in the aroma deterioration of beer. Finally, the kinetic parameters, Ea and k, were calculated, and it was observed that the Arrhenius equation described well the temperature dependence of the reaction rate constant. Measuring the concentration of methional and phenylacetaldehyde may provide information about the key steps along the process that most affect the flavor stability of beer, which may be useful in establishing the best storage conditions

Characterization, physicochemical stability, and evaluation of in vitro digestibility of solid lipid microparticles produced with palm kernel oil and tristearin

Solid lipid particles have been investigated by food researchers due to their ability to enhance the incorporation and bioavailability of lipophilic bioactives in aqueous formulations. The objectives of this study were to evaluate the physicochemical stability and digestibility of lipid microparticles produced with tristearin and palm kernel oil. The motivation for conducting this study was the fact that mixing lipids can prevent the expulsion of the bioactive from the lipid core and enhance the digestibility of lipid structures. The lipid microparticles containing different palm kernel oil contents were stable after 60 days of storage according to the particle size and zeta potential data. Their calorimetric behavior indicated that they were composed of a very heterogeneous lipid matrix. Lipid microparticles were stable under various conditions of ionic strength, sugar concentration, temperature, and pH. Digestibility assays indicated no differences in the release of free fatty acids, which was approximately 30% in all analises. The in vitro digestibility tests showed that the amount of palm kernel in the particles did not affect the percentage of lipolysis, probably due to the high amount of surfactants used and/or the solid state of the microparticles.The authors are grateful to the FAPESP and CNPq for the scholarships granted (J.C.S., FAPESP fellowships 2010/13229-8 and 2012/02316-2, and T. R. B, FAPESP fellowship 2010/15031-0) and to Agropalma S/A for their generous palm kernel oil donation. Author Ana C. Pinheiro gratefully acknowledges the fellowship (SFRH/BD/48120/2008) granted by the Fundacao para a Ciencia e Tecnologia (FCT, Portugal)

Adaptabilidade e estabilidade de cultivares de mandioca (Manihot esculenta Crantz) para os rendimentos de raízes e amido em duas microrregiões produtoras no Estado de Sergipe: safra 2008/2009.

As condições edafoclimáticas dos tabuleiros costeiros nordestinos permitem o desenvolvimento da mandioca em toda a sua extensão. Existem áreas que têm mostrado grande aptidão para o incremento da lavoura, a exemplo dos tabuleiros costeiros localizados nos municípios de Lagarto e Umbaúba, no Estado de Sergipe, onde o rendimento de raízes tuberosas tem ultrapassado o patamar de 50 ton/ha, no âmbito experimental, com % de amido oscilando entre 28% a 34% (CARVALHO et al., 2009). Atualmente, nessa região, variedades e clones de mandioca são postos a competir em vários ambientes (anos, locais, épocas de colheita). Nesse caso, a classificação relativa entre eles pode não ser coincidente, o que dificulta a identificação de materiais efetivamente superiores. Esse fato é minimizado, mediante a seleção de cultivares com maior estabilidade fenotípica (RAMALHO et al., 1993). Diversos trabalhos ressaltam a importância e a influência da interação cultivares x ambientes, principalmente, nas fases do programa que envolvem a avaliação final e a recomendação de cultivares (RAMALHO et al., 1993, CRUZ e REGAZZI, 1997 e VIDIGAL FILHO et al., 2007). O objetivo deste trabalho foi averiguar a adaptabilidade e a estabilidade de cultivares de mandioca, quanto aos rendimentos de raízes e amido, em duas microrregiões produtoras de mandioca no Estado de Sergipe, para fins de recomendação

Desempenho de cultivares de mandioca para farinha e fécula no estado de Sergipe na safra 2007/2008.

A seleção e a recomendação de cultivares mais produtivas é objetivo fundamental dos programas de melhoramento genético de qualquer espécie cultivada. O processo de seleção é frequentemente realizado avaliando-se o desempenho das cultivares em diferentes ambientes (ano, local, épocas de semeadura e de colheita), fornecendo subsídios para embasar recomendações com mais segurança. Em Sergipe, o programa de avaliação de cultivares de mandioca para farinha e fécula vem realizando anualmente uma rede de ensaios em diversos ambientes (locais e épocas de colheita) visando selecionar cultivares de melhor adaptação associada à melhor época de colheita. Carvalho et al., (2009a e 2009b) adotando esse procedimento recomendaram diversas cultivares de mandioca para exploração comercial no Estado de Sergipe e adjacências, a exemplo de Sagrilo et al., (2002 ) e Kvitschal et al. ( 2003), em outras regiões. Dessa forma, realizou-se o presente trabalho objetivando selecionar e recomendar novas cultivares de mandioca para exploração comercial no Estado de Sergipe, após realizar a avaliação dessas cultivares em vários ambientes.Melhoramento genético. Resumo n. 86

Adaptabilidade do feijão-caupi para a produtividade de grãos no Ceará.

O objetivo deste trabalho foi avaliar a adaptabilidade de feijão-caupi e a produtividade de grãos no Ceará