3,774 research outputs found

    DNA-psoralen: single-molecule experiments and first principles calculations

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    The authors measure the persistence and contour lengths of DNA-psoralen complexes, as a function of psoralen concentration, for intercalated and crosslinked complexes. In both cases, the persistence length monotonically increases until a certain critical concentration is reached, above which it abruptly decreases and remains approximately constant. The contour length of the complexes exhibits no such discontinuous behavior. By fitting the relative increase of the contour length to the neighbor exclusion model, we obtain the exclusion number and the intrinsic intercalating constant of the psoralen-DNA interaction. Ab initio calculations are employed in order to provide an atomistic picture of these experimental findings.Comment: 9 pages, 4 figures in re-print format 3 pages, 4 figures in the published versio

    Measurement, model testing, and legislative influence in the European Union

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    Within the last several years, new data have become available to test the various theoretical models of EU decision-making, and, in doing so, to assess actor influence. This article examines the extent to which the recent DEU and DEUII datasets provide sufficient information to distinguish between competing theoretical models of legislative decision-making, and accurately assess the power of the different branches of EU government. It argues that insufficient attention has been paid to measurement error in these data. Once measurement error is accounted for, it becomes clear that these data do not provide sufficient information to distinguish between most models of legislative politics. Moreover, empirical models that fail to account for measurement error are likely to lead researchers to erroneous conclusions about actors’ legislative influence. </jats:p

    Qualidade sensorial da carne de cordeiros Morada Nova com ou sem suplementação, abatidos em diferentes idades.

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    Resumo: Objetivou-se caracterizar a carne de cordeiros Morada Nova abatidos em diferentes idades e submetidos ou não a suplementação. Foram utilizados 32 cordeiros, machos, não castrados, abatidos aos 60, 78, 106 e 134 dias, com grupo de 8 cordeiros em cada abate, num esquema fatorial 4x2. Avaliaram-se os parâmetros de dureza, suculência, sabor, cor, aroma e aceitação global, para tanto foi utilizado um painel treinado com 13 pessoas. A suplementação não modificou as características sensoriais, enquanto a idade ao abate não altera dureza, suculência e aceitação global. O sabor é intensificado com o aumento da idade de abate e a cor diminui com o aumento da idade, mas só foi diferente mesmo aos 60 e 134 dias, os outros são iguais. O aroma aos 60 dias é menos intenso que o restante. [Sensory quality of meat from lambs Morada Nova with or without supplementation, slaughtered in different ages]. Abstract: bjective of characterizing the meat from lambs Morada Nova slaughtered in different ages and submitted or no supplementation. We used 32 uncastrated males, lambs slaughtered at 60, 78, 106 and 134 days, with a group of 8 lambs in each slaughter, a factorial 4 x 2. We evaluated the parameters of hardness, juiciness, taste, colour, aroma and global acceptance, for both used a trained panel with 13 people. No supplementation modified sensory characteristics, while the age at slaughter does not change hardness, juiciness and global acceptance. The flavor is intensified with increasing age of slaughter and the color decreases with increasing age, but was only really different to 60 and 134 days, others are equal. The aroma to 60 days is less intense than the rest

    In silico and in vivo analysis reveal a novel gene in Saccharomyces cerevisiae trehalose metabolism

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    BACKGROUND: The ability to respond rapidly to fluctuations in environmental changes is decisive for cell survival. Under these conditions trehalose has an essential protective function and its concentration increases in response to enhanced expression of trehalose synthase genes, TPS1, TPS2, TPS3 and TSL1. Intriguingly, the NTH1 gene, which encodes neutral trehalase, is highly expressed at the same time. We have previously shown that trehalase remains in its inactive non-phosphorylated form by the action of an endogenous inhibitor. Recently, a comprehensive two-hybrid analysis revealed a 41-kDa protein encoded by the YLR270w ORF, which interacts with NTH1p. RESULTS: In this work we investigate the correlation of this Trehalase Associated Protein, in trehalase activity regulation. The neutral trehalase activity in the ylr270w mutant strain was about 4-fold higher than in the control strain. After in vitro activation by PKA the ylr270w mutant total trehalase activity increased 3-fold when compared to a control strain. The expression of the NTH1 gene promoter fused to the heterologous reporter lacZ gene was evaluated. The mutant strain lacking YLR270w exhibited a 2-fold increase in the NTH1-lacZ basal expression when compared to the wild type strain. CONCLUSIONS: These results strongly indicate a central role for Ylr270p in inhibiting trehalase activity, as well as in the regulation of its expression preventing a wasteful futile cycle of synthesis-degradation of trehalose

    Physiological and biochemical responses of sugarcane varieties to salt stress.

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    Salt stress is one of the most limiting environmental factors for agricultural yields in the Semiarid region of Brazil. Considering the expansion of areas with sugarcane crops in this region, the selection of more adapted plant varieties to this environment is an essential tool for the sustainability of this activity. Thus, the objective of the present work was to evaluate the physiological and biochemical responses of plants of ten sugarcane varieties to salt stress. The experiment was conducted in a greenhouse using a randomized block design, in a 6×10 factorial arrangement consisting of six salinity levels in the irrigation water (0, 1.0, 2.0, 4.0, 6.0, and 8.0 dS m-1) and ten sugarcane varieties (VAT 90212, RB 72454, RB 867515, Q 124, RB 961003, RB 957508, SP 791011, RB 835089, RB 92579, and SP 943206), with three replications. Salt waters were applied every two days to increase the soil moisture to field capacity and promote leaching. The gas exchange, chlorophyll content, and total soluble and reducing sugars of leaves were evaluated at 90 days after planting. The highest chlorophyll contents were found in plants of the varieties Q 124, RB 96103, RB 835089, and SP 943206. The effect of salinity on the sugarcane plants affected their leaf gas exchanges and total soluble and reducing sugar contents, denoting the adaptability of plants to the stress conditions evaluated. The decrease of stomatal conductance resulted in decreases in photosynthetic rates in plants of all sugarcane varieties evaluated, except for RB 86751

    Síndrome de Frey – Uma visão global do tema

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    ResumoIntroduçãoO Síndrome de Frey resulta de uma lesão irritativa ou mecânica das fibras vegetativas do nervo auriculotemporal. Esta lesão provoca uma regeneração aberrante das fibras parassimpáticas pós-ganglionares para os recetores das glândulas sudoríparas e vasos sanguíneos, provocando aumento da sensibilidade, eritema cutâneo e sudação durante a mastigação de alimentos.MétodosEste trabalho foi realizado com base numa pesquisa bibliográfica realizada na base de dados PubMed, utilizando a combinação de palavras (mesh terms): «Frey's syndrome» or «Auriculotemporal syndrome» or «Gustatory sweating».ResultadosNo total foram encontrados 262 artigos que foram publicados no período compreendido entre 1974-2012. Após a leitura dos resumos de cada artigo estes foram selecionados e categorizados a fim de facilitar a análise dos mesmos e excluir os menos relevantes para o estudo. Esta categorização permitiu atingir os objetivos deste trabalho que consistem em apresentar os aspetos principais relativos à Síndrome de Frey, nomeadamente a sua neuroanatomia, fisiopatologia, incidência, etiologia, diagnóstico, prevenção e tratamento.Conclusão Dos doentes submetidos a parotidectomia, apenas uma pequena percentagem apresenta queixas espontâneas sugestivas deste síndrome. Deste modo, o uso rotineiro de procedimentos preventivos deve ser considerado e devidamente ponderado, uma vez que poderão mascarar possíveis recidivas tumorais a longo prazo. Por outro lado, a primeira opção de tratamento continua a ser a injeção de toxina botulínica tipo A.AbstractIntroductionFrey's syndrome is caused by a mechanical irritative lesion of the vegetative fibers from the auriculotemporal nerve. This lesion causes an abnormal regeneration of the post-ganglionic parasympathetic fibers to the receptors sweat gland and blood vessels, causing increases sensitivity, skin erythema and sudation during meals.MethodsA literature search was performed in PubMed, using a combination of words (Mesh terms), such as «Frey's syndrome» or «syndrome Auriculotemporal» or «gustatory sweating».Results262 articles, published between 1974 and 2012, were found. Papers were selected and categorized into several groups after reading their abstracts, to facilitate their analysis and exclude the less relevant to the study. This selection led to the achievement of the objectives of this paper, presenting the most relevant aspects of Frey's syndrome, including neuroanatomy, physiopathology, incidence, etiology, diagnosis, prevention and treatment.ConclusionAmong the patients who had parotidectomies only a few mentioned spontaneously symptoms suggestive of Frey's syndrome. Therefore the routine use of preventive procedures must be previously and thoroughly considered since it may mask tumoral relapse in the long term. When treatment is needed, the first choice is, still, the injection of botulinum toxin type A

    Utilização de biofertilizante na produção de melão do tipo amarelo.

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    O objetivo deste trabalho foi avaliar a influência de diferentes doses de biofertilizante na cultura do melão do tipo Amarelo.Suplemento. Edição dos Anais do 53 Congresso Brasileiro de Olericultura, jul. 2014
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