1,666 research outputs found

    Genes Dev

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    The SAGA (Spt-Ada-Gcn5 acetyltransferase) coactivator complex contains distinct chromatin-modifying activities and is recruited by DNA-bound activators to regulate the expression of a subset of genes. Surprisingly, recent studies revealed little overlap between genome-wide SAGA-binding profiles and changes in gene expression upon depletion of subunits of the complex. As indicators of SAGA recruitment on chromatin, we monitored in yeast and human cells the genome-wide distribution of histone H3K9 acetylation and H2B ubiquitination, which are respectively deposited or removed by SAGA. Changes in these modifications after inactivation of the corresponding enzyme revealed that SAGA acetylates the promoters and deubiquitinates the transcribed region of all expressed genes. In agreement with this broad distribution, we show that SAGA plays a critical role for RNA polymerase II recruitment at all expressed genes. In addition, through quantification of newly synthesized RNA, we demonstrated that SAGA inactivation induced a strong decrease of mRNA synthesis at all tested genes. Analysis of the SAGA deubiquitination activity further revealed that SAGA acts on the whole transcribed genome in a very fast manner, indicating a highly dynamic association of the complex with chromatin. Thus, our study uncovers a new function for SAGA as a bone fide cofactor for all RNA polymerase II transcription

    Coupling Constant pH Molecular Dynamics with Accelerated Molecular Dynamics

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    An extension of the constant pH method originally implemented by Mongan et al. (J. Comput. Chem.2004, 25, 2038−2048) is proposed in this study. This adapted version of the method couples the constant pH methodology with the enhanced sampling technique of accelerated molecular dynamics, in an attempt to overcome the sampling issues encountered with current standard constant pH molecular dynamics methods. Although good results were reported by Mongan et al. on application of the standard method to the hen egg-white lysozyme (HEWL) system, residues which possess strong interactions with neighboring groups tend to converge slowly, resulting in the reported inconsistencies for predicted pKa values, as highlighted by the authors. The application of the coupled method described in this study to the HEWL system displays improvements over the standard version of the method, with the improved sampling leading to faster convergence and producing pKa values in closer agreement to those obtained experimentally for the more slowly converging residues

    Contribuição das universidades na revisão da Política Nacional de Promoção da Saúde

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    Resumo Em 2014, a Política Nacional de Promoção da Saúde passou por um processo participativo de revisão, que teve como colaboradores gestores públicos, participantes de movimentos sociais, professores e pesquisadores de universidades. Nesse processo, foi necessário conhecer e analisar como se deram as contribuições dos diferentes atores envolvidos e como elas foram incorporadas à nova versão da Política. O objetivo deste estudo é discutir a contribuição das universidades na revisão da Política Nacional de Promoção da Saúde. Utilizando-se a técnica Delphi, questionários foram enviados, por correio eletrônico, a líderes de grupos de pesquisa das universidades brasileiras; o envio foi organizado em duas rodadas, tendo a última sido realizada somente após a análise dos consensos e dissensos da primeira. A partir da análise dos formulários, concluiu-se que as contribuições das universidades à nova Política Nacional de Promoção da Saúde estão relacionadas à sua estrutura, princípios e valores, objetivos, temas prioritários e eixos operacionais

    Survival estimates of bycatch individuals discarded from bivalve dredges

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    The fate of released bycatch is an issue of great interest for fisheries research and management. Survival experiments were carried out to assess the survival capacity of animals damaged and discarded during clam dredging operations. Three common bycatch species, two fish (Trachinus vipera; Dicologlossa cuneata) and one crab (Polybius henslowii), were collected during the sorting of catches from a commercial dredging boat. An arbitrary score scale was used to quantify the type and extent of damage to the organisms. Onboard, damaged individuals were placed in tanks containing seawater which were subsequently transferred to the laboratory. Survival experiments were conducted during the subsequent 48h. D. cuneata exhibited the lowest mortality after 48h (54%), followed by P. henslowii (65%) and T. vipera (81%). Despite the magnitude of the percentage mortalities determined, the average number of individuals estimated to die during a 15 minutes tow (standard commercial fishing time) was relatively small: 1.2, 3.24 and 11 for D. cuneata, T. vipera and P. henslowii, respectively. Nevertheless, when these figures are extrapolated to cover all the dredging fleet the impact of this practice on the populations of the species studied can be significant, particulary for D. cuneata

    Stress ocupacional no ensino : um estudo com professores dos 3º ciclo e ensino secundário

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    Este trabalho foi realizado com 689 professores portugueses, a leccionarem nos terceiro ciclo e ensino secundário. Foram avaliados indicadores de stress, “burnout”, saúde física e satisfação profissional. Observaram-se valores significativos de stress ocupacional (perto de 40%), e de “burnout” (10% na exaustão emocional, 3% na baixa realização pessoal e 1% na despersonalização), vários problemas de saúde física e valores de insatisfação profissional perto dos 20%. As análises de regressão múltipla apontaram diferentes variáveis preditoras para as três dimensões do “burnout” (62% de variância explicada na exaustão emocional, 16% na realização pessoal e 13% na despersonalização). As análises discriminantes e “t-test” para amostras independentes demonstraram maior stress ocupacional nas mulheres, nos professores mais velhos, nos profissionais com vínculos profissionais mais precários, nos professores com mais horas de trabalho e com mais alunos em sala de aula. No final, apresentam-se as limitações do estudo e as implicações para a investigação futura.(undefined

    The Effectiveness of Pharmacological and Non-Pharmacological Interventions for Improving Glycaemic Control in Adults with Severe Mental Illness: A Systematic Review and Meta-Analysis

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    People with severe mental illness (SMI) have reduced life expectancy compared with the general population, which can be explained partly by their increased risk of diabetes. We conducted a meta-analysis to determine the clinical effectiveness of pharmacological and non-pharmacological interventions for improving glycaemic control in people with SMI (PROSPERO registration: CRD42015015558). A systematic literature search was performed on 30/10/2015 to identify randomised controlled trials (RCTs) in adults with SMI, with or without a diagnosis of diabetes that measured fasting blood glucose or glycated haemoglobin (HbA1c). Screening and data extraction were carried out independently by two reviewers. We used random effects meta-analysis to estimate effectiveness, and subgroup analysis and univariate meta-regression to explore heterogeneity. The Cochrane Collaboration’s tool was used to assess risk of bias. We found 54 eligible RCTs in 4,392 adults (40 pharmacological, 13 behavioural, one mixed intervention). Data for meta-analysis were available from 48 RCTs (n = 4052). Both pharmacological (mean difference (MD), -0.11mmol/L; 95% confidence interval (CI), [-0.19, -0.02], p = 0.02, n = 2536) and behavioural interventions (MD, -0.28mmol//L; 95% CI, [-0.43, -0.12], p<0.001, n = 956) were effective in lowering fasting glucose, but not HbA1c (pharmacological MD, -0.03%; 95% CI, [-0.12, 0.06], p = 0.52, n = 1515; behavioural MD, 0.18%; 95% CI, [-0.07, 0.42], p = 0.16, n = 140) compared with usual care or placebo. In subgroup analysis of pharmacological interventions, metformin and antipsychotic switching strategies improved HbA1c. Behavioural interventions of longer duration and those including repeated physical activity had greater effects on fasting glucose than those without these characteristics. Baseline levels of fasting glucose explained some of the heterogeneity in behavioural interventions but not in pharmacological interventions. Although the strength of the evidence is limited by inadequate trial design and reporting and significant heterogeneity, there is some evidence that behavioural interventions, antipsychotic switching, and metformin can lead to clinically important improvements in glycaemic measurements in adults with SMI
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