66 research outputs found

    Diagenesis of Holocene Beachrock in Northeastern Brazil: Petrology, Isotopic Evidence and Age

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    This work aims to understand beachrock formation during Holocene through petrology, geochemistry and dating of a core located 5,43m deep in relation to present-day sea-level in the Piedade Beach in Jaboatao dos Guararapes- PE. The core is located 143 meters distant from the coast line towards mainland. Four lithofacies have been identified, taking into account differences in texture and sedimentary structures. The framework grain size ranges from medium to very coarse sand, indicating variations in depositional energy. Petrographic data indicate that the beachrocks have values of 64.23% to 70.69% of framework composed of quartz grains. Carbonate cement (represents 13.5%) consisting of high magnesium calcite surrounding grains as isopachous fringe (4.15% to 11.95%), micritic cement (0.60% to 6.42%) and equant cement (0.26% to 7.01%), indicates marine environment precipitation. The results of the isotopic composition of carbon and oxygen present valuesof 3.09‰ to 3.89‰, with an average of 3.63‰ to δ13CPDB and of -0.91‰ to 0.96‰, with an average of 0.54‰ to δ18OPDB, suggesting that the cement is formed in a shallow marine environment with freshwater influence. The values obtained in paleotemperature vary from 21ºC to 30ºC, with an average of 23ºC, with little variation indicating precipitation in a shallow water environment. In the study area, the beachrocks are indicators of sea level and the results suggest that between 7.509 years B.P. and 5982 years B.P. there was a marine transgression process, with sea level 9.18 m lower than the current sea level

    Protective effect of ions against cell death induced by acid stress in Saccharomyces

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    Saccharomyces boulardii is a probiotic used to prevent or treat antibiotic-induced gastrointestinal disorders and acute enteritis. For probiotics to be effective they must first be able to survive the harsh gastrointestinal environment. In this work, we show that S. boulardii displayed the greatest tolerance to simulated gastric environments compared with several Saccharomyces cerevisiae strains tested. Under these conditions, a pH 2.0 was the main factor responsible for decreased cell viability. Importantly, the addition of low concentrations of sodium chloride (NaCl) protected cells in acidic conditions more effectively than other salts. In the absence of S. boulardii mutants, the protective effects of Na 1 in yeast viability in acidic conditions was tested using S. cerevisiae Na 1 -ATPases (ena1-4), Na 1 /H 1 antiporter (nha1D) and Na 1 /H 1 antiporter prevacuolar (nhx1D) null mutants, respectively. Moreover, we provide evidence suggesting that this protection is determined by the plasma membrane potential, once altered by low pH and low NaCl concentrations. Additionally, the absence or low expression/activity of Ena proteins seems to be closely related to the basal membrane potential of the cells

    Um cenário de possibilidades para o estágio curricular supervisionado no contexto de um instituto federal

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    Este artigo trata da pesquisa acerca da formação inicial de professores, focando o Estágio Curricular Supervisionado (ECS). O objetivo foi investigar o processo de estágio e buscar novas alternativas de atuação do docente recém-formado pelo viés da pesquisa. Neste texto, apresenta-se um recorte da pesquisa, que trata do atual modelo de prática do ECS e apresenta uma proposta de alteração pelo viés da pesquisa. Para tanto, utilizou-se, como metodologia, a análise de documentos, de fontes escritas e orais, além da observação in loco nas escolas em que os estudantes realizaram os estágios. Participaram quatro professores orientadores de estágio e quatro estagiários. Os resultados revelam que o estágio vem sendo realizado numa concepção de racionalidade técnica e, para a sua superação, é preciso que seja tratado como elemento articulador que perpassa as diferentes disciplinas que compõem a matriz curricular, e que ocorram reflexões coletivas para estudo, planejamento, execução e avaliação das ações.Este artículo trata de la investigación acerca de la formación inicial de maestros, enfocada en la Pasantía Curricular Supervisada (PCS). El objetivo fue investigar el proceso de pasantía y buscar nuevas alternativas de actuación del docente recién graduado por la tendencia de la investigación. En este texto, se presenta un recorte de investigación que trata del modelo actual de práctica de la PCS y presenta una propuesta de alteración por la tendencia de la investigación. Para tanto, se ha utilizado como metodología el análisis de documentos, fuentes escritas y orales, además de la observación in loco en las escuelas en las que los estudiantes realizaron sus pasantías. Participaron cuatro profesores orientadores de pasantía y cuatro pasantes. Los resultados revelan que la pasantía es realizada en una concepción de racionalidad técnica y, para su superación, es necesario que sea tratada como un elemento articulador que permea las diferentes asignaturas que componen la matriz curricular, y que ocurran reflexiones colectivas para estudio, planeamiento, ejecución y evaluación de las acciones.This article reports of the research about the initial formation of teachers, focusing on the Supervised Curricular Internship (SCI). The main goal was to investigate the internship process and search for new alternatives of action for the recently graduated teacher. In this paper, we present a framed research about the current SCI model and proposes an alteration through research bias. For this purpose, we accessed action research methodology, analyzing written documents, oral sources and on-site observation in schools where teaching students perform internships. Four teachers and four interns took part on the research. The results show that the internship has taken place in a technical rationality conception. For its overcoming, internship has to be treated as an articulating element that crosses the different disciplines that are part of the curricular matrix. It’s also necessary that collective reflections are made about study, planning, implementation and evaluation of actions.Apoio financeiro do CIEC (Centro de Investigação em Estudos da Criança, IE, UMinho; UI 317 da FCT, Portugal) através do Projeto Estratégico UID/CED/00317/2013, financiado através dos Fundos Nacionais da FCT (Fundação para a Ciência e a Tecnologia), cofinanciado pelo Fundo Europeu de Desenvolvimento Regional (FEDER) através do COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI) com a referência POCI-01-0145-FEDER-007562info:eu-repo/semantics/publishedVersio

    Evaluation and comparison between methods of measurement of systolic blood pressure in healthy conscious cats

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    Após validação de dois diferentes métodos de mensuração de pressão arterial sistólica (PAS) não invasivos ou indiretos (oscilométrico e Doppler vascular) com o invasivo ou direto (cateterização arterial padrão ouro) em 12 gatos hígidos anestesiados de mesma faixa etária, os métodos não invasivos foram avaliados e comparados em 24 gatos hígidos e conscientes, divididos em quatro grupos de idade. Em cada animal, procedeu-se à mensuração da pressão pelos métodos Doppler e oscilométrico. O método oscilométrico foi o primeiro a ser realizado, e, logo em seguida, o método Doppler. Os valores considerados foram obtidos das médias de sete medidas consecutivas para cada método, com intervalo de 30 segundos entre elas. A primeira medida e as medidas discrepantes (variação ˃ 20% PAS), obtidas com sinais óbvios de estresse e/ou com movimentação do animal, foram descartadas. Os métodos de mensuração oscilométrico e Doppler, embora tenham apresentado médias estatisticamente diferentes em todos os grupos, quando comparados em cada grupo, apresentaram uma correlação significativa, alta e positiva. Ou seja, sempre que for obtido um valor elevado por um método, o mesmo fato ocorrerá com o outro método e vice-versa. Clinicamente, a diferença observada não é relevante, uma vez que a diferença média dos valores obtida pelos dois métodos, em cada grupo, foi menor que 1,1%.After two different validation systolic blood pressure measurement methods (PAS), not invasive or indirect (oscillometric and doppler vascular) with invasive or direct (arterial catheterization - Gold Standard) in 12 anesthetized healthy cats of the same age group, not invasive methods were evaluated and compared in 24 healthy conscious cats, divided into four age groups. In each animal, we proceeded to measure the pressure by Doppler and oscillometric methods. The oscillometric method was the first to be performed, and, shortly thereafter, the doppler method. The values considered were obtained from averages from seven consecutive measurements for each method with an interval of thirty seconds between them. The first measurement and disparate measurements (range ˃ 20% PAS) obtained with obvious signs of stress and / or animal movement were discarded. Methods of oscillometric and doppler measurement, although statistically different averages were shown in all groups when compared, each group showed a significant high positive correlation, meaning that when a high value is obtained by a method, the same occurs with the other method, and vice versa. Clinically, the observed difference is not relevant since the mean difference values obtained by the two methods, in each group was lower than 1.1%

    The TAL Effector PthA4 Interacts with Nuclear Factors Involved in RNA-Dependent Processes Including a HMG Protein That Selectively Binds Poly(U) RNA

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    Plant pathogenic bacteria utilize an array of effector proteins to cause disease. Among them, transcriptional activator-like (TAL) effectors are unusual in the sense that they modulate transcription in the host. Although target genes and DNA specificity of TAL effectors have been elucidated, how TAL proteins control host transcription is poorly understood. Previously, we showed that the Xanthomonas citri TAL effectors, PthAs 2 and 3, preferentially targeted a citrus protein complex associated with transcription control and DNA repair. To extend our knowledge on the mode of action of PthAs, we have identified new protein targets of the PthA4 variant, required to elicit canker on citrus. Here we show that all the PthA4-interacting proteins are DNA and/or RNA-binding factors implicated in chromatin remodeling and repair, gene regulation and mRNA stabilization/modification. The majority of these proteins, including a structural maintenance of chromosomes protein (CsSMC), a translin-associated factor X (CsTRAX), a VirE2-interacting protein (CsVIP2), a high mobility group (CsHMG) and two poly(A)-binding proteins (CsPABP1 and 2), interacted with each other, suggesting that they assemble into a multiprotein complex. CsHMG was shown to bind DNA and to interact with the invariable leucine-rich repeat region of PthAs. Surprisingly, both CsHMG and PthA4 interacted with PABP1 and 2 and showed selective binding to poly(U) RNA, a property that is novel among HMGs and TAL effectors. Given that homologs of CsHMG, CsPABP1, CsPABP2, CsSMC and CsTRAX in other organisms assemble into protein complexes to regulate mRNA stability and translation, we suggest a novel role of TAL effectors in mRNA processing and translational control
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