41 research outputs found

    Integration of VICbus, FDL, SCI and Ethernet in the CERN CASCADE data acquisition system

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    Cascade is a multi-processor real-time data-acquisition system for HEP experiments developed at CERN by the ECP-DS group. Configurations supported today include VMEbus processors running OS-9 and UNIX workstations. The CASCADE data acquisition processes, called stages communicate via links, at present VICbus between VME crates and Ethernet between VMEbus processors and workstations. Work is in progress to introduce new inter-stage links based on the Fast Data Link between VME crates and on SCI for data exchange between SUN stations. The paper gives a short description of the architecture of CASCADE with emphasis on the link aspects. The implementation and current status of the inter-stage links based on VICbus, Ethernet, FDI, and SCI will be described and results on the performances presented

    Bacterial size matters:Multiple mechanisms controlling septum cleavage and diplococcus formation are critical for the virulence of the opportunistic pathogen Enterococcus faecalis

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    Enterococcus faecalis is an opportunistic pathogen frequently isolated in clinical settings. This organism is intrinsically resistant to several clinically relevant antibiotics and can transfer resistance to other pathogens. Although E. faecalis has emerged as a major nosocomial pathogen, the mechanisms underlying the virulence of this organism remain elusive. We studied the regulation of daughter cell separation during growth and explored the impact of this process on pathogenesis. We demonstrate that the activity of the AtlA peptidoglycan hydrolase, an enzyme dedicated to septum cleavage, is controlled by several mechanisms, including glycosylation and recognition of the peptidoglycan substrate. We show that the long cell chains of E. faecalis mutants are more susceptible to phagocytosis and are no longer able to cause lethality in the zebrafish model of infection. Altogether, this work indicates that control of cell separation during division underpins the pathogenesis of E. faecalis infections and represents a novel enterococcal virulence factor. We propose that inhibition of septum cleavage during division represents an attractive therapeutic strategy to control infections

    Simple scoring system to predict in-hospital mortality after surgery for infective endocarditis

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    BACKGROUND: Aspecific scoring systems are used to predict the risk of death postsurgery in patients with infective endocarditis (IE). The purpose of the present study was both to analyze the risk factors for in-hospital death, which complicates surgery for IE, and to create a mortality risk score based on the results of this analysis. METHODS AND RESULTS: Outcomes of 361 consecutive patients (mean age, 59.1\ub115.4 years) who had undergone surgery for IE in 8 European centers of cardiac surgery were recorded prospectively, and a risk factor analysis (multivariable logistic regression) for in-hospital death was performed. The discriminatory power of a new predictive scoring system was assessed with the receiver operating characteristic curve analysis. Score validation procedures were carried out. Fifty-six (15.5%) patients died postsurgery. BMI >27 kg/m2 (odds ratio [OR], 1.79; P=0.049), estimated glomerular filtration rate 55 mm Hg (OR, 1.78; P=0.032), and critical state (OR, 2.37; P=0.017) were independent predictors of in-hospital death. A scoring system was devised to predict in-hospital death postsurgery for IE (area under the receiver operating characteristic curve, 0.780; 95% CI, 0.734-0.822). The score performed better than 5 of 6 scoring systems for in-hospital death after cardiac surgery that were considered. CONCLUSIONS: A simple scoring system based on risk factors for in-hospital death was specifically created to predict mortality risk postsurgery in patients with IE

    Wellbore stresses induced by the nonlinear deformation of an inflatable packer

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    Fabric-Dependent Hydro-Mechanical Behavior of Pre-Fractured Rocks

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    Fabric and boundary conditions determine the hydro-mechanical behavior of rock masses. In this numerical study, a set of two-dimensional models are created to simulate various layered rock fabrics. The fabric varies in terms of density and relative orientation of natural fractures. The behavior of differently-structured blocky media is analyzed due to a mechanical disturbance that resembles the creation of an opening-mode discontinuity in the medium analogous to hydraulic stimulation. The response of the blocky medium is also investigated in terms of the amplitude of this idealized stimulation resembling the viscosity or flow rate of the injected fluid. The analysis is performed using the distinct element formulation, which can capture the opening and shear failure of existing discontinuities and deformations of the rock blocks globally-disturbed under high far-field stresses. The results show fundamental differences in the deformation field of rock masses with different fabrics. Local shear dilation along natural fractures and global kinematic dilation of the stimulated reservoir area are dominant mechanisms although both processes are more limited than the case of rigid block assemblies under low stresses. The amplitude of kinematic dilation differs for different fabrics, and it implies the extent of enhancement in the permeability of the rock mass
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