4,056 research outputs found

    More than an RNA matchmaker: Expanding the roles of Hfq into ribosome biogenesis

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    Ribosome biogenesis is a complex process involving multiple factors. The work described here is primarily centered in the study of ribosomal RNA, highlighting its central role in translation regulation. We have uncovered new regulators involved in rRNA processing, folding and degradation pathways. For the first time, we demonstrate that the widely conserved RNA chaperone Hfq, mostly known as the sRNA-mRNA matchmaker, acts as a ribosomal assembly factor in Escherichia coli, affecting rRNA processing, ribosome levels, translation efficiency and accuracy. This function is suggested to be independent of its activity as sRNA-regulator.(...

    Deriving software design models from a set of business processes

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    Requirements elicitation is a crucial activity and one of the first steps in software development process. A popular way to capture and describe requirements is through UML use case models. Transforming require- ment specifications into software design models is a complex and error prone software development activity. Software design usually involves several models, each one representing a different perspective. One of those perspectives is the data perspective which can be modeled using a data model. Although of the importance of this model, few works has been done to derive a data model from use case model. The 4SRS (4-Step Rule Set) method generates a logical architecture of a software-based system, based on a use case model. This paper proposes an approach to adapt and extend the 4SRS method in order to generate a data model supporting the generated logical architecture and the elicited requirements based in a set of business process models.This work has been supported by FCT - Fudação para a Ciência e Tecnologia in the scope of the project: PEst-UID/CEC/00319/201

    Aminosquaraines as potential photodynamic agents: Synthesis and evaluation of in vitro cytotoxicity

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    © 2017 Elsevier Ltd The synthesis of several aminosquaraine cationic dyes displaying strong absorption within the so-called phototherapeutic window (650–850 nm) is described. Their cytotoxicity, under dark and illuminated conditions, was tested against several human tumor cell lines (breast, lung, cervical and hepatocellular carcinomas) and non-tumor porcine liver primary cells. All compounds showed to inhibit the growth of the tumor cells upon irradiation more than in the absence of light, in more or less extension, clearly exhibiting photodynamic activity. The photosensitizing ability against some cell lines, together with the low toxicity for the non-tumor primary PLP2 cells displayed by some of the compounds synthetized, turns them into potential candidates as photosensitizers for PDT.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER for CIMO (UID/AGR/00690/2013) and CQ-VR (UID/QUI/00616/2013) financial support.info:eu-repo/semantics/publishedVersio

    Projecto Rodentia : etologia aplicada na sala de aula do 1º Ciclo

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    p. 275-279O Projecto Rodentia, implementado no ano 2006/2007, visa promover a cultura científica em alunos do 1º ciclo do Ensino Básico, familiarizando-os com o Método Científico e desenvolvendo competências conceptuais, processuais e atitudinais, com base na Etologia Aplicada e na reflexão ética sobre o bem-estar animal. Foram instalados em três salas de aula habitats especialmente desenhados, contendo cada um dois ratos de laboratório. Inicialmente orientadas, as crianças começaram de modo progressivamente autónomo a propor actividades experimentais, registar e interpretar resultados e tirara conclusões, tacitamente aprendendo o Método Científico. Recorreu-se à observação comportamental e análise de trabalhos dos alunos para avaliar o desenvolvimento da lógica condicional nestes alunos

    Review - Understanding β-lactamase Producing Klebsiella pneumoniae

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    Klebsiella pneumoniae is a nosocomial pathogen commonly implicated in hospital outbreaks with a propensity for antimicrobial resistance towards mainstay β-lactam antibiotics and multiple other antibiotic classes. The successful proliferation, transmission and infection of the Gram-negative bacterium can be attributed to a myriad of factors including host factors, environmental factors, virulence factors and a large repertoire of antibiotic resistance mechanisms. The poor treatment outcomes and limited treatment options are consequences of the successful pathogenesis and spread of antibiotic resistance in the increasingly common β-lactamase producing K. pneumoniae bacterium. The review briefly explores the biology, successful pathogenesis and antibiotic resistance of K. pneumoniae as well as the detection and characterisation techniques of important strains

    Diversity and seasonal changes in the ichthyofauna of rocky tidal pools from Praia Vermelha and São Roque, Santa Catarina, Brazil

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    Copyright © 2011 Tecpar.Este trabalho realizou-se entre Abril de 1998 e Maio de 1999 e visou o estudo das comunidades de peixes em duas poças de maré situadas nas praias de Praia Vermelha (PV) e São Roque (SR), Santa Catarina, Brasil. A poça de PV é maior e mais próxima do sub-mareal. Os exemplares foram coletados mensalmente, durante a baixa-mar, com o anestésico quinaldina. Em PV recolheram-se 1287 peixes pertencentes a 19 espécies enquanto em SR foram capturados 553 peixes de 11 species. Em ambas as poças as espécies dominantes foram Bathygobius soporator (Gobiidae), Abudefduf saxatilis (Pomacentridae), Parablennius pilicornis (Blenniidae), Labrisomus nuchipinnis (Labrisomidae) e Epinephelus marginatus (Serranidae). A diversidade e o número de peixes foram maiores nos meses de Verão e correspondem a uma época de recrutamento para as espécies A. saxatilis e E. marginatus.ABSTRACT: A survey of the tidal pool fish community was carried out between April 1998 and May 1999, at the beaches of Praia Vermelha (PV) and São Roque (SR), Santa Catarina, Brazil. The pool of PV was bigger and closer to the subtidal. Specimens were collected monthly at low tide, using quinaldine. In PV we collected 1287 fish belonging to 19 species and in SR 553 fish were caught corresponding to 11 species. In both pools, dominant species were Bathygobius soporator (Gobiidae), Abudefduf saxatilis (Pomacentridae), Parablennius pilicornis (Blenniidae), Gobiesox barbatulus (Gobiesocidae), Labrisomus nuchipinnis (Labrisomidae) and Epinephelus marginatus (Serranidae). Summer months had higher abundance and diversity values, and correspond to a recruitment season for both A. saxatilis and E. marginatus

    Leaves and decoction of Juglans regia L.: Different performances regarding bioactive compounds and in vitro antioxidant and antitumor effects

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    Juglans regia L. (walnut) leaves are considered a source of healthcare compounds, and have been widely used in traditional medicine. Furthermore, they have been reported as a source of bioactive molecules such as the antioxidant phenolic compounds. In the present study, organic acids, mono and oligosaccharides, and tocopherols were analyzed in leaves and decoction (widely used for topical applications). Furthermore, the phenolic composition and bioactivity of walnut leaves was determined in its decoction and methanol extract. Malic acid, sucrose, alpha-tocopherol and 3-O-caffeoylquinic acids and quercetin O-pentoside were the most abundant organic acid, disaccharide, tocopherol isomer and phenolic compounds, respectively. Methanol extract presented higher antioxidant and antitumor potential than decoction; both samples did not show toxicity for non-tumor liver primary cells. This study provides a more complete characterization of phenolic compounds of walnut leaves, and as far as we know, this is the first time that the presence of procyanidins and taxifolin derivatives, as also tocopherols were reported in J. regia leaves.The authors are grateful to Fundacao para a Ciencia e a Tecnologia (FCT, Portugal) for financial support to CIMO (strategic project PEst-OE/AGR/UI0690/2011). L. Barros and R.C. Calhelha also thank to FCT, POPH-QREN and FSE for their grants (SFRH/BPD/4609/2008 and SFRH/BPD/68344/2010, respectively). The GIP-USAL is financially supported by the Spanish Government through the Consolider-Ingenio 2010 Programme (FUN-C-FOOD, CSD2007-00063). M. Duenas thanks the Programa Ramon y Cajal for a contract
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