12 research outputs found

    Impact of the deletion of the six mce operons in Mycobacterium smegmatis

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    The Mycobacterium smegmatis genome contains six operons designated mce (mammalian cell entry). These operons, which encode membrane and exported proteins, are highly conserved in pathogenic and non-pathogenic mycobacteria. Although the function of the Mce protein family has not yet been established in Mycobacterium smegmatis, the requirement of the mce4 operon for cholesterol utilization and uptake by Mycobacterium tuberculosis has recently been demonstrated. In this study, we report the construction of an M. smegmatis knock-out mutant deficient in the expression of all six mce operons. The consequences of these mutations were studied by analyzing physiological parameters and phenotypic traits. Differences in colony morphology, biofilm formation and aggregation in liquid cultures were observed, indicating that mce operons of M. smegmatis are implicated in the maintenance of the surface properties of the cell. Importantly, the mutant strain showed reduced cholesterol uptake when compared to the parental strain. Further cholesterol uptake studies using single mce mutant strains showed that the mutation of operon mce4 was reponsible for the cholesterol uptake failure detected in the sextuple mce mutant. This finding demonstrates that mce4 operon is involved in cholesterol transport in M. smegmatis.Fil: Klepp, Laura Ines. Instituto Nacional de Tecnología Agropecuaria. CNIA Castelar. Centro de Investigación en Ciencias Veterinarias y Agronómicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Forrellad, Marina Andrea. Instituto Nacional de Tecnología Agropecuaria. CNIA Castelar. Centro de Investigación en Ciencias Veterinarias y Agronómicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Osella, Ana Virginia. Instituto Nacional de Tecnología Agropecuaria. CNIA Castelar. Centro de Investigación en Ciencias Veterinarias y Agronómicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Blanco, Federico Carlos. Instituto Nacional de Tecnología Agropecuaria. CNIA Castelar. Centro de Investigación en Ciencias Veterinarias y Agronómicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Stella, Emma Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Médicas; ArgentinaFil: Bianco, María Verónica. Instituto Nacional de Tecnología Agropecuaria. CNIA Castelar. Centro de Investigación en Ciencias Veterinarias y Agronómicas; ArgentinaFil: Santangelo, María de la Paz. Instituto Nacional de Tecnología Agropecuaria. CNIA Castelar. Centro de Investigación en Ciencias Veterinarias y Agronómicas; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Médicas; ArgentinaFil: Sassetti, Cristopher. Massachusetts Institute of Technology; Estados UnidosFil: Jackson, Mary. State University of Colorado - Fort Collins; Estados UnidosFil: Cataldi, Ángel Adrián. Instituto Nacional de Tecnología Agropecuaria. CNIA Castelar. Centro de Investigación en Ciencias Veterinarias y Agronómicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bigi, Fabiana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. CNIA Castelar. Centro de Investigación en Ciencias Veterinarias y Agronómicas; ArgentinaFil: Morbidoni, Héctor Ricardo. Universidad Nacional de Rosario. Facultad de Ciencias Médicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Caracterização de pastas de cimento Portland com adição de sílica visando a imobilização de Cr(VI)

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    In the scope of sustainability, the generation of different residues through human activities requires the exploration of techniques for final disposal. Among these residues, there are agricultural residues, as well as the residues of heavy metals, both potentially polluting. This work reports the analysis on the immobilization of chromium (VI) in Portland cement pastes (PC) with the addition of silica (SiO2) obtained from rice husk ash (RHA). The cement pastes were evaluated from the perspective of mechanical properties through the compression test. Regarding the hydration development, the pastes were evaluated by SEM, XRD and FTIS. Aiming at the study of Cr(VI) immobilization, solubilized extracts were obtained for analysis through UV-VIS spectrophotometry. The results suggest that the SiO2 from the RHA showed a predominantly amorphous. Regarding the pastes, the comparison of the strength of the different traits at the same ages revealed that they are not significantly different. As to the XRD, the results suggest that, in the traits with K2Cr2O7, there are alterations in the hydration process. The immobilization efficiency resulted greater than 99%, but there was no favorable effect of the addition of silica to PC in the immobilization of chromium (VI).No âmbito da sustentabilidade, a geração de diferentes resíduos através das atividades humanas demanda a exploração de técnicas para disposição final. Dentre esses resíduos, estão os agrícolas e os metais pesados, ambos potencialmente poluidores. Este trabalho relata a análise da imobilização de cromo (VI) em pastas de cimento Portland (CP) com adição de sílica (SiO2) obtida de cinzas de casca de arroz (CCA). As pastas de CP foram avaliadas sob a perspectiva das propriedades mecânicas por ensaio de compressão. Relativo ao desenvolvimento da hidratação, as pastas foram avaliadas por MEV, DRX e FTIR. Visando o estudo da imobilização do Cr(VI), obteve-se extratos solubilizados para análise por espectrofotometria UV-VIS. Os resultados sugerem que a SiO2 de CCA apresentou-se predominantemente amorfa. Com relação às pastas, a comparação da resistência dos diferentes traços nas mesmas idades revelou que não são significativamente diferentes. Acerca da DRX, os resultados sugerem que nos traços com K2Cr2O7 existem alterações no processo de hidratação. A eficiência de imobilização resultou maior que 99%, mas não se constatou efeito favorável da adição de sílica ao CP na imobilização do cromo (VI)

    Rifted Margins: State of the Art and Future Challenges

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    8 pages, 1 figureImprovements in seismic imaging, computing capabilities, and analytical methods, as well as a number of industry deep-water wells sampling distal offshore settings, have underpinned new concepts for rifted margin evolution developed in the last two decades; these mark significant progress in our understanding of extensional systems. For example, the tectonic, sedimentary, and magmatic processes linked to the formation of rifted margins have been overhauled, giving rise to more quantitative approaches and new concepts. However, these processes cannot be understood in isolation, requiring consideration of the continuum in which inheritance and physical processes are integrated within a plate tectonic framework. The major progress and fundamental developments of past research in rifted margins have been made hand-in-hand with other domains of Earth Sciences and have fundamental implications for the understanding of key geological systems such as active rifts, the ocean lithosphere, subduction zones, and collisional orogens. The “IMAGinING RIFTING” workshop, organized in Pontresina-Switzerland in September 2017, gathered researchers from all disciplines working on rifts and rifted margins, and included participants from academia and industry. This contribution summarizes the workshop discussions, in addition to outlining our state-of-the-art knowledge of rifted margins. We highlight future challenges in unraveling the processes and conditions under which these extensional systems form and, ultimately, how tectonic plates rupture and new oceans are born. Our aims here are to provide a framework for future research endeavors and to promote collaboration not only within the rift and rifted margins communities, but across other Earth Science discipline

    A large-scale exome array analysis of venous thromboembolism

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    Although recent Genome‐Wide Association Studies have identified novel associations for common variants, there has been no comprehensive exome‐wide search for low‐frequency variants that affect the risk of venous thromboembolism (VTE). We conducted a meta‐analysis of 11 studies comprising 8,332 cases and 16,087 controls of European ancestry and 382 cases and 1,476 controls of African American ancestry genotyped with the Illumina HumanExome BeadChip. We used the seqMeta package in R to conduct single variant and gene‐based rare variant tests. In the single variant analysis, we limited our analysis to the 64,794 variants with at least 40 minor alleles across studies (minor allele frequency [MAF] ~0.08%). We confirmed associations with previously identified VTE loci, including ABO, F5, F11, and FGA. After adjusting for multiple testing, we observed no novel significant findings in single variant or gene‐based analysis. Given our sample size, we had greater than 80% power to detect minimum odds ratios greater than 1.5 and 1.8 for a single variant with MAF of 0.01 and 0.005, respectively. Larger studies and sequence data may be needed to identify novel low‐frequency and rare variants associated with VTE risk

    Conflitos e ambiguidades de papéis no trabalho de juízes: as percepções de juízes portugueses

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    Reformas em judiciários de diversos países criaram um novo papel para os juízes, um papel gerencial, em que juízes assumem novas responsabilidades relacionadas às atividades administrativas. Esse novo papel é diferente do papel tradicional, focado em tarefas judiciais e tem gerado conflitos no trabalho de juízes. Com base nesse contexto, o presente estudo tem como objetivo identificar e discutir conflitos e ambiguidades envolvendo os papéis judicial e gerencial, desempenhados por juízes de Portugal. A pesquisa foi realizada em Portugal, entre 2013 e 2014, e os dados foram coletados por meio de entrevistas em profundidade com 12 juízes. Os principais conflitos são: incompatibilidade entre a realização de atividades judiciais e administrativas; carga de trabalho elevada e equipe administrativa insuficiente e desmotivada; produtividade versus qualidade do trabalho judicial; e alta responsabilidade do cargo e baixo salário. As principais ambiguidades identificadas nas entrevistas referem-se a: relação formal entre juízes e pessoal administrativo; função do juiz no processo de planejamento dos tribunais; o critério para distribuição de processos judiciais entre juízes; e o critério de avaliação do desempenho de juízes. Os resultados são discutidos e sugeridas pesquisas adicionais.info:eu-repo/semantics/publishedVersio

    Review of Particle Physics, 2002-2003

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    This biennial Review summarizes much of Particle Physics. Using data from previous editions, plus 2205 new measurements from 667 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors, probability, and statistics. This edition features expanded coverage of CP violation in B mesons and of neutrino oscillations. For the first time we cover searches for evidence of extra dimensions (both in the particle listings and in a new review). Another new review is on Grand Unified Theories. A booklet is available containing the Summary Tables and abbreviated versions of some of the other sections of this full Review. All tables, listings, and reviews (and errata) are also available on the Particle Data Group website: http://pdg.lbl.gov
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