2,409 research outputs found

    Structural analysis of Salmonella enterica effector protein SopD

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    Salmonella outer protein D (SopD) is a type III secreted virulence effector protein from Salmonella enterica. Full-length SopD and SopD lacking 16 amino acids at the N-terminus (SopDDeltaN) have been expressed as fusions with GST in Escherichia coli, purified with a typical yield of 20-30 mg per litre of cell culture and crystallized. Biophysical characterization has been carried out mainly on SopDDeltaN. Analytical size exclusion chromatography shows that SopDDeltaN is monomeric and probably globular in aqueous solution. The secondary structure composition, calculated from the CD spectrum, is mixed (38% alpha-helix and 26% beta-strand). Sequence analysis indicates that SopD contains a coiled coil motif, as found in numerous other type III secretion system-associated proteins. This suggests that SopD has the potential for one or more heterotypic protein-protein interactions. Limited trypsin digestion of SopDDeltaN, monitored by both one-dimensional proton NMR spectroscopy and SDS-PAGE, shows that the protein has a large, protease-resistant core domain of 286 amino acid residues. This single-domain architecture suggests that SopD lacks a cognate chaperone. In crystallization trials, SopDDeltaN produced better crystals than either full-length SopD or trypsin-digested SopDDeltaN. Diffraction to 3.0 Angstrom resolution has so far been obtained from crystals of SopDDeltaN

    Solving the Boltzmann Equation on GPU

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    We show how to accelerate the direct solution of the Boltzmann equation using Graphics Processing Units (GPUs). In order to fully exploit the computational power of the GPU, we choose a method of solution which combines a finite difference discretization of the free-streaming term with a Monte Carlo evaluation of the collision integral. The efficiency of the code is demonstrated by solving the two-dimensional driven cavity flow. Computational results show that it is possible to cut down the computing time of the sequential code of two order of magnitudes. This makes the proposed method of solution a viable alternative to particle simulations for studying unsteady low Mach number flows.Comment: 18 pages, 3 pseudo-codes, 6 figures, 1 tabl

    Towards Zero-waste Mineral Carbon Sequestration Via Two-way Valorization of Ironmaking Slag

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    A three-stage process was developed to transform blast furnace slag (BFS) into two valuable products: precipitated calcium carbonate (PCC) and zeolitic materials. The conceptualized process aims to simultaneously achieve sustainable CO2 sequestration and solid waste elimination. Calcium is first selectively extracted by leaching with an organic acid, followed by carbonation of the leachate to precipitate CaCO3. In parallel, the hydrothermal conversion of the extracted solid residues in alkali solution induces the dissolution/precipitation mechanism that leads to the formation of micro- and meso-porous zeolitic materials. Leaching selectivity was identified as a key factor in the valorization potential of both products. Acetic acid satisfactorily limited the leaching of aluminium, required for the subsequent synthesis of zeolites, and carbonation of the acetic acid leachate resulted in the production of PCC of varied mineralogy and morphology, depending on processing conditions. In the hydrothermal conversion stage, the formation of zeolitic phases was observed, and their characteristics were found to vary depending on the calcium extraction efficiency in the previous stage, and the alkali (NaOH) concentration. The zeolitic phases produced, in order of increasing valorization potential, were: tobermorite, sodalite, lazurite, and analcime

    Оценка фискальной иллюзии при налогообложении доходов физических лиц

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    Фискальная иллюзия сама по себе не является негативным явлением, она всего лишь следствие осуществляемой фискальной политики государства. Тем не менее, фискальная иллюзия нарушает представление экономических агентов о масштабах государственного влияния в перераспределении своих доходов и тем самым способствует принятию ими не самых эффективных экономических решений.Фіскальна ілюзія сама по собі не є негативним явищем, вона всього лише слідство здійснюваної фіскальної політики держави. Проте, фіскальна ілюзія порушує уявлення економічних агентів про масштаби державного впливу в перерозподілі своїх доходів і тим самим сприяє ухваленню ними не найефективніших економічних рішень

    Genomic Organization, Splice Variants and Expression of CGMl, a CD66-related Member of the Carcinoembryonic Antigen Gene Family

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    The tumor marker carcinoembryonic antigen (CEA) belongs to a family of proteins which are composed of one immunogiobulin variable domain and a varying number of immunoglobulin constant-like domains. Most of the membrane-bound members, which are anchored either by a glycosylphosphatidylinositol moiety or a transmembrane domain, have been shown to convey cell adhesion in vitro. Here we describe two splice variants of CGMI. a transmembrane member of the CEA family without immunoglobulin constant.like domains. CGM1a and CGM1c contain cytopiasmic domains of 71 and 31 amino acids, respectively, The cytoplasmic region of CGM1a is encoded by four exons (Cyt1-Cyt4). Differential splicing of the Cyt1 exon (53 bp)..

    Review of Top Quark Physics Results

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    As the heaviest known fundamental particle, the top quark has taken a central role in the study of fundamental interactions. Production of top quarks in pairs provides an important probe of strong interactions. The top quark mass is a key fundamental parameter which places a valuable constraint on the Higgs boson mass and electroweak symmetry breaking. Observations of the relative rates and kinematics of top quark final states constrain potential new physics. In many cases, the tests available with study of the top quark are both critical and unique. Large increases in data samples from the Fermilab Tevatron have been coupled with major improvements in experimental techniques to produce many new precision measurements of the top quark. The first direct evidence for electroweak production of top quarks has been obtained, with a resulting direct determination of VtbV_{tb}. Several of the properties of the top quark have been measured. Progress has also been made in obtaining improved limits on potential anomalous production and decay mechanisms. This review presents an overview of recent theoretical and experimental developments in this field. We also provide a brief discussion of the implications for further efforts.Comment: 119 pages, 55 figure
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