123 research outputs found

    Growth and texture of Spark Plasma Sintered Al2O3 ceramics: a combined analysis of X-rays and Electron Back Scatter Diffraction

    Full text link
    Textured alumina ceramics were obtained by Spark Plasma Sintering (SPS) of undoped commercial a-Al2O3 powders. Various parameters (density, grain growth, grain size distribution) of the alumina ceramics, sintered at two typical temperatures 1400{\deg}C and 1700{\deg}C, are investigated. Quantitative textural and structural analysis, carried out using a combination of Electron Back Scattering Diffraction (EBSD) and X-ray diffraction (XRD), are represented in the form of mapping, and pole figures. The mechanical properties of these textured alumina ceramics include high elastic modulus and hardness value with high anisotropic nature, opening the door for a large range of applicationsComment: 16 pages, 6 figures, submitted to J. Appl. Phy

    Human Cytomegalovirus IE1 Protein Elicits a Type II Interferon-Like Host Cell Response That Depends on Activated STAT1 but Not Interferon-γ

    Get PDF
    Human cytomegalovirus (hCMV) is a highly prevalent pathogen that, upon primary infection, establishes life-long persistence in all infected individuals. Acute hCMV infections cause a variety of diseases in humans with developmental or acquired immune deficits. In addition, persistent hCMV infection may contribute to various chronic disease conditions even in immunologically normal people. The pathogenesis of hCMV disease has been frequently linked to inflammatory host immune responses triggered by virus-infected cells. Moreover, hCMV infection activates numerous host genes many of which encode pro-inflammatory proteins. However, little is known about the relative contributions of individual viral gene products to these changes in cellular transcription. We systematically analyzed the effects of the hCMV 72-kDa immediate-early 1 (IE1) protein, a major transcriptional activator and antagonist of type I interferon (IFN) signaling, on the human transcriptome. Following expression under conditions closely mimicking the situation during productive infection, IE1 elicits a global type II IFN-like host cell response. This response is dominated by the selective up-regulation of immune stimulatory genes normally controlled by IFN-γ and includes the synthesis and secretion of pro-inflammatory chemokines. IE1-mediated induction of IFN-stimulated genes strictly depends on tyrosine-phosphorylated signal transducer and activator of transcription 1 (STAT1) and correlates with the nuclear accumulation and sequence-specific binding of STAT1 to IFN-γ-responsive promoters. However, neither synthesis nor secretion of IFN-γ or other IFNs seems to be required for the IE1-dependent effects on cellular gene expression. Our results demonstrate that a single hCMV protein can trigger a pro-inflammatory host transcriptional response via an unexpected STAT1-dependent but IFN-independent mechanism and identify IE1 as a candidate determinant of hCMV pathogenicity

    A low noise, large dynamic range pulse amplifier

    No full text

    A low noise, large dynamic range pulse amplifier

    No full text

    Troubles du rythme cardiaque

    No full text

    The ECLine-driver: a flexible, 20MHz, 256 words ECLine generator

    No full text
    The ECLine-Driver is a dual 256 words of 16 bits fast ECLine generator fully controlled by CAMAC. Designed to fit requirements of high energy physics experiments, its flexibility makes it a general purpose unit. It is used on the LEP L3 experiment, at CERN, to implement two applications. In the first one, it generates the "trigger detector" response in order to exercise the different trigger processors under experimental conditions. In the second one, it generates some 10000 synchronisation signals required to drive the level-1 energy trigger processor. 70 units are installed on the experiment

    A classification scheme for sedimentary architectures arising from aeolian-fluvial system interactions: Permian examples from southeast Utah, USA

    No full text
    International audienceThe preservation of the sedimentary deposits of arid environments is determined by both geomorphic and geologic processes. Sedimentary evidence of aeolian-fluvial system interactions in arid-climate settings are preserved in both recent and ancient sedimentary successions. However, despite considerable prior sedimentological research, there is no unifying scheme to provide generalized definitions of commonly occurring types of preserved aeolian-fluvial interactions. This study addresses this shortcoming by introducing a novel classification scheme for sedimentary architectures arising from such system interactions. The scheme is demonstrated through reference to examples from the Permian Cutler Group, Paradox Basin, Southeast Utah, USA - a sedimentary record of competing aeolian dune-field and fluvial-fan systems along a palaeo-coastline. Well-preserved, laterally continuous outcrops arranged in different orientations enable three-dimensional architectural characterization. The sedimentary record of eight distinct types of aeolian-fluvial interaction are identified: (i) water-table-controlled interdune sedimentation; (ii) deposits of low-energy fluvial floods; (iii) isolated fluvial channel-fills originating from episodic and confined flooding of interdunes in orientations parallel to the trend of dune crestlines; (iv) channel fills oriented perpendicular to the trend of dune crestlines; (v) amalgamated fluvial channel elements resulting from persistent, long-lived but confined dune-field flooding; (vi) deposits of unconfined sheet-like flood deposits; (vii) fluvial breaching of dunes and their reworking by catastrophic flooding; (viii) aeolian reworking of fluvial deposits. Each interaction type is characterized in terms of preserved sedimentary facies, architectural element geometries and associated proprieties, to demonstrate sedimentary variability in three dimensions. Results provide a guide with which to make sedimentological comparisons and interpretations between active systems and their preserved depositional record
    corecore