5,418 research outputs found

    Stable Determination of the Electromagnetic Coefficients by Boundary Measurements

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    The goal of this paper is to prove a stable determination of the coefficients for the time-harmonic Maxwell equations, in a Lipschitz domain, by boundary measurements

    Tropical Dominating Sets in Vertex-Coloured Graphs

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    Given a vertex-coloured graph, a dominating set is said to be tropical if every colour of the graph appears at least once in the set. Here, we study minimum tropical dominating sets from structural and algorithmic points of view. First, we prove that the tropical dominating set problem is NP-complete even when restricted to a simple path. Then, we establish upper bounds related to various parameters of the graph such as minimum degree and number of edges. We also give upper bounds for random graphs. Last, we give approximability and inapproximability results for general and restricted classes of graphs, and establish a FPT algorithm for interval graphs.Comment: 19 pages, 4 figure

    Surveillance of nosocomial infections: a preliminary study on yeast carriage on hands of healthcare workers

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    Hospital-acquired fungal infection is increasing. The aim of this preliminary study was to evaluate the frequency and distribution of yeast carriage on the hands of healthcare workers (HCW) from different departments. The study was conducted in three departments (Surgery, Intensive Care Unit, Obstetrics and Gynaecology) of a hospital in Campania, southern Italy. Over a six-month period, 50 healthcare workers were randomly tested. Imprints of palms and fingertips were taken monthly during the morning shift. The plate with yeast was counted and Candida species were identified. Risk factors for hand contamination were determined. Hand carriage of yeast and Candida species in the three departments were found in the following percentages: Surgery (50% and 49%); Intensive Care Unit (61% and 57%); Obstetrics and Gynaecology (65% and 59%). No significant difference in the frequency or distribution of yeast and Candida sp. recovered in the three departments was ascertained by comparing every two months? data, the hand carriage of yeast and Candida species found in the three departments; this varied ? min to max ? according to the following percentages: Surgery [(45%-54%) and (42%-58%)]; Intensive Care Unit [(53%-66%) and (56%-59%)]; Obstetrics and Gynaecology [(62%-69%) and (57%-63%)]. The only factor associated with yeast carriage on the hands of healthcare workers was the absence of gloving during healthcare procedure (p = 0.0192). We conclude that in our study yeast carriage on the HCWs? hands is common in the three departments investigated, but its causes are unclear. Careful use of gloving may reduce pathogenic yeast on hands

    Surveillance of nosocomial infections: a preliminary study on hand hygiene compliance of healthcare workers

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    The observance of hand hygiene compliance is important to reduce cross-infection by micro-organisms. The aim of this preliminary study was to evaluate the level of hand hygiene in healthcare workers from different departments, with particular emphasis on transient flora. The study was conducted in three departments (Surgery, Intensive Care Unit, Obstetrics and Gynecology) of a hospital in Campania, southern Italy. Over a six-month period, 50 healthcareworkers wererandomly tested. Imprints of palms and fingertips were taken monthly during the morning shift. The number of colonies per plate was counted and transient pathogens were identified. Risk factors for hand contamination were determined. Total flora was found in the following CFU means per palm and per five fingertips (95% CI): Obstetrics and Gynecology [palms 130 CFUs (95% CI 85-180); fingertips 125 CFUs (95% CI 92-160)]; ICU [palms 80 CFUs (95% CI 58-99); fingertips 62 CFUs (95% CI 45-82)]; Surgery [palms 75 CFUs (95% CI 41-120); fingertips 70 CFUs (95% CI 52-90)] Transient flora was found on 39% of healthcare workers?hands. The only factor associated with hand contamination by transient flora was the absence of gloving during healthcare procedure(P=0.02)

    First experimental test of Bell inequalities performed using a non-maximally entangled state

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    We report on the realisation of a new test of Bell inequalities using the superposition of type I parametric down conversion produced in two different non-linear crystals pumped by the same laser, but with different polarisation. The produced state is non-maximally entangled. We discuss the advantages and the possible developments of this configuration

    Numerical studies towards practical large-eddy simulation

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    Large-eddy simulation developments and validations are presented for an improved simulation of turbulent internal flows. Numerical methods are proposed according to two competing criteria: numerical qualities (precision and spectral characteristics), and adaptability to complex configurations. First, methods are tested on academic test-cases, in order to abridge with fundamental studies. Consistent results are obtained using adaptable finite volume method, with higher order advection fluxes, implicit grid filtering and "low-cost" shear-improved Smagorinsky model. This analysis particularly focuses on mean flow, fluctuations, two-point correlations and spectra. Moreover, it is shown that exponential averaging is a promising tool for LES implementation in complex geometry with deterministic unsteadiness. Finally, adaptability of the method is demonstrated by application to a configuration representative of blade-tip clearance flow in a turbomachine

    Perinatal Tuberculosis: Is it a Forgotten Disease?

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    Perinatal tuberculosis is an uncommon condition but with a high mortality and a challenging diagnosis. We present four cases of perinatal tuberculosis managed between 1991-2014 in a Spanish Tertiary Hospital. The infection should be considered in patients with progressive respiratory symptoms and with a poor response to conventional antibiotic therapy, especially in those with positive epidemiologic risk. Bronchoscopy can be a useful tool for diagnosis
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