486 research outputs found

    The Effect of CodY on stationary phase mutagenesis in Bacillus subtilis

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    We examine the notion that cells in conditions of stress accumulate mutation is in genes under selection via transcription processes. CodY is a global transcriptional regulator in many Gram positives, including soil and pathogenic microbes. In conditions of exponential growth and when branch chain amino acids and GTP are in abundance CodY acts as a transcriptional repressor of many metabolic operons. This transitional repression saves the cell energy and allows efficient use of resources. In conditions of starvation, CodY relieves repression of genes involved in acquisition of nutrients and degradation of carbon sources (genes under selection). Here, we compare the accumulation of mutations in genes under selection in wild type and CodY

    Morototó (Didymopanax morototoni Aubl. Decne & Planch) em plantios homogêneos sob diferentes espaçamentos, no oeste do estado do Pará.

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    O espaçamento adotado em um plantio florestal exerce grande influência no número de tratos culturais, na taxa de crescimento, índice de mortalidade e custos de produção. Objetivou-se avaliar a influência do espaçamento no crescimento de morototó (Didymopanax morototoni Aubl. Decne & Planch). O delineamento experimental adotado foi o de blocos ao acaso com quatro tratamentos (espaçamento 3 m x 2 m; 3 m x 3 m; 3 m x 4 m e 4 m x 4 m) e quatro repetições (A, B, C e D). As características avaliadas foram: sobrevivência (%) e variáveis dendrométricas altura (m) e DAP (cm). Aos dez anos de idade os diferentes arranjos espaciais não influenciaram a sobrevivência dos indivíduos de morototó. As taxas de sobrevivência variaram de 85,6 % a 60,6 %. O espaçamento teve pouca influência no crescimento em altura das árvores avaliadas. Contudo, o DAP desde o terceiro ano se mostrou sensível à diferença de densidade do povoamento e detectou-se uma tendência no crescimento diamétrico à medida que diminuía a densidade de plantas

    Online media scans: Applying systematic review techniques to assess statewide human papillomavirus vaccination activities

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    Background. Although the human papillomavirus (HPV) vaccine has been approved for use in adolescents in the US for over a decade, vaccination uptake remains low. Of concern, HPV vaccine coverage is below the national average in Minnesota, USA. To understand the reach of current HPV programming and research, we use an online media scan; this method may be applied to other jurisdictions to gain insight about various public health issues.Design and Methods. This online media scan describes the nature and scope of ongoing activities to increase HPV vaccination in Minnesota. The media scan included: a) structured internet searches of HPV vaccine health education/promotion activities ongoing in Minnesota since 2013, and b) searches in research databases of the published literature on HPV vaccination in Minnesota from 2013 to 2018. Results. Searches resulted in 880 online and 142 research article matches, with 40 and 36 meeting selection criteria. Results were categorized by activities focusing on race/ethnicity, sex, health providers, parents, lesbian, gay, bisexual, transgender and queer or questioning (LGBTQ) populations, geographic location, catchup vaccination, and insurance status. Most activities were statewide (52% health education/promotion and 35% research), followed by activities located in entirely urban areas (15% health education/promotion and 41% research) with only 6% of health education/promotion activities and 2% of research activities carried out in entirely rural areas.Conclusions. A range of local and statewide HPV vaccine health education/promotion and research activities were identified in Minnesota. Several efforts partnered with American Indian and Somali/Somali-American communities, but fewer activities focused on HPV vaccination among LGBTQ youth and HPV vaccination in rural areas

    O Programa PROAMBIENTE na Transamazônica: lições aprendidas.

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    O objetivo desse artigo é apontar e discutir algumas lições deixadas pelo PROAMBIENTE, programa federal de apoio ao fortalecimento da agricultura familiar na Amazônia brasileira. O local de realização da pesquisa foi o polo transamazônica localizado na região de integração do Xingu, estado do Pará. Através de entrevistas aplicadas aos agricultores familiares, assim como a atores institucionais que participaram do período em que o programa esteve na região (2002 - 2006), chegou-se a um conjunto de lições que devem ser consideradas para o êxito de programas que visem o desenvolvimento rural. São elas: i. Necessidade de seleção de agricultores com real interesse e capacidade de assumir riscos; ii. Eliminação da cultura assistencialista; iii. Prioridade de atividades chaves: o caso do pagamento por serviços ambientais; iv. Utilização de uma nova abordagem do sistema produtivo; v. Assistência técnica e extensão rural com enfoque inovador; vi. Fortalecimento das organizações rurais locais; vii. Investimento na verticalização da produção; viii. O cuidado na geração de expectativas

    Associação de espécies florestais com forrageiras para ocupação de áreas degradadas.

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    Estrogens and genomic instability in human cancer cells-involvement of Src/Raf/Erk signaling in micronucleus formation by estrogenic chemicals

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    This article is available open access through the publisher’s website. Copyright @ 2008 The Authors.Reports of the ability of estrogenic agents such as 17β-estradiol (E2), estriol (E3) and bisphenol A (BPA) to induce micronuclei (MN) in MCF-7 breast cancer cells have prompted us to investigate whether these effects are linked to activation of the estrogen receptor (ER) α. Coadministration of tamoxifen and the pure ER antagonist ICI 182 780 to cells treated with E2 and E3 did not lead to significant reductions in micronucleus frequencies. Since these antiestrogens interfere with the transcriptional activity of the ER and block promotion of ER-dependent gene expression, it appears that this process is not involved in micronucleus formation. However, ER activation also triggers rapid signaling via the Src/Raf/extracellular signal-regulated kinase (Erk) pathway. When MCF-7 cells were exposed to E2 and BPA in combination with the specific kinase inhibitors pyrazolopyrimidine and 2′-amino-3′-methoxyflavone, reductions in micronucleus frequencies occurred. These findings suggest that the Src/Raf/Erk pathway plays a role in micronucleus formation by estrogenic agents. Enhanced activation of the Src/Raf/Erk cascade disturbs the localization of Aurora B kinase to kinetochores, leading to a defective spindle checkpoint with chromosome malsegregation. Using antikinetochore CREST antibody staining, a high proportion of micronucleus containing kinetochores was observed, indicating that such processes are relevant to the induction of MN by estrogens. Our results suggest that estrogens induce MN by causing improper chromosome segregation, possibly by interfering with kinase signaling that controls the spindle checkpoint, or by inducing centrosome amplification. Our findings may have some relevance in explaining the effects of estrogens in the later stages of breast carcinogenesis.European Commissio
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