3,665 research outputs found

    Field and photon enhanced electron emission characteristics of cadmium sulphide field emitters

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    Field and photon enhanced electron emission characteristics of cadmium sulfide field emitter

    In vivo nematicidal potential of camel milk on Heligmosomoides polygyrus gastro-intestinal nematode of rodents

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    Following our previous fi ndings on the in vitro anthelmintic effect of camel milk on Haemonchus contortus, the current study aimed at investigating its in vivo effect. Investigations were carried out using mice infected with Heligmosomoides polygyrus which is a parasite commonly used to test the effi cacy of anthelmintics. Thirty six Swiss white mice of both sexes aged 5 – 6 weeks old, and weighing between 20 and 25 g were orally infected with 0.5 ml dose of 100, 1-week-old H. polygyrus infective larvae (L3 ). After the pre-patent period, infected animals were randomly divided into 6 groups of 6 animals each. The nematicidal effi cacy of camel milk was monitored through faecal egg count reduction (FECR) and total worm count reduction (TWCR). Four doses (8.25; 16.5; 33.0; 66.0 ml/kg body weight (bw)) for fresh camel milk and 22 mg/kg bw for albendazole were studied using a bioassay. Albendazole and 4 % dimethylsulfoxide were included in the protocol as reference drug and placebo, respectively. For all tested doses except 8.25 ml/kg bw, camel milk was effective in vivo against H. polygyrus reducing both faecal egg count and worm count (p < 0.05). The dose 66 ml/kg bw showed the highest nematicidal activity causing a 76.75 % FECR and a 69.62 % TWCR 7 day after initiating the treatment. These results support the possible use of camel milk in the control of gastro-intestinal helminthiasis

    On the global well-posedness for the Boussinesq system with horizontal dissipation

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    In this paper, we investigate the Cauchy problem for the tridimensional Boussinesq equations with horizontal dissipation. Under the assumption that the initial data is an axisymmetric without swirl, we prove the global well-posedness for this system. In the absence of vertical dissipation, there is no smoothing effect on the vertical derivatives. To make up this shortcoming, we first establish a magic relationship between urr\frac{u^{r}}{r} and ωθr\frac{\omega_\theta}{r} by taking full advantage of the structure of the axisymmetric fluid without swirl and some tricks in harmonic analysis. This together with the structure of the coupling of \eqref{eq1.1} entails the desired regularity.Comment: 32page

    Existence of global strong solutions in critical spaces for barotropic viscous fluids

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    This paper is dedicated to the study of viscous compressible barotropic fluids in dimension N2N\geq2. We address the question of the global existence of strong solutions for initial data close from a constant state having critical Besov regularity. In a first time, this article show the recent results of \cite{CD} and \cite{CMZ} with a new proof. Our result relies on a new a priori estimate for the velocity, where we introduce a new structure to \textit{kill} the coupling between the density and the velocity as in \cite{H2}. We study so a new variable that we call effective velocity. In a second time we improve the results of \cite{CD} and \cite{CMZ} by adding some regularity on the initial data in particular ρ0\rho_{0} is in H1H^{1}. In this case we obtain global strong solutions for a class of large initial data on the density and the velocity which in particular improve the results of D. Hoff in \cite{5H4}. We conclude by generalizing these results for general viscosity coefficients

    Controlling for openness in the male-dominated collaborative networks of the global film industry.

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    Studies of gender inequality in film industries have noted the persistence of male domination in creative roles (usually defined as director, producer, writer) and the slow pace of reform. Typical policy remedies are premised on aggregate counts of women as a proportion of overall industry participation. Network science offers an alternative way of identifying and proposing change mechanisms, as it puts emphasis on relationships instead of individuals. Preliminary work on applying network analysis to understand inequality in the film industry has been undertaken. However, in this study we offer a comprehensive approach that enables us to not only understand what inequality in the film industry looks like through the lens of network science but also how we can attempt to address this issue. We offer a data-driven simulation framework that investigates various what-if scenarios when it comes to network evolution. We then assess each of these scenarios with respect to its potential to address gender inequality in the film industry. As suggested by previous studies, inequality is exacerbated when industry networks are most closed. We review evidence from three different national film industries on network relationships in creative teams and identify a high proportion of men who only work with other men. In response to this observation, we test several mechanisms through which industry structures may generate higher levels of openness. Our results reveal that the most critical factor for improving network openness is not simply the statistical improvement of the number of women in a network, nor the removal of men who do not work with women. The most likely behavioural changes to a network will involve the production of connections between women and powerful men

    System measure for persistence in holographic recording and application to singly-doped and doubly-doped lithium niobate

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    We define a measure for persistence in holographic recording. Using this measure and the known measures for dynamic range and sensitivity, we compare the performance of singly-doped and doubly-doped LiNbO3 crystals. We show that the range of performance that can be obtained using doubly-doped crystals is much larger than that obtained using singly-doped ones. (C) 2001 Optical Society of America

    Health-care associated infections rates, length of stay, and bacterial resistance in an intensive care unit of Morocco: Findings of the International Nosocomial Infection Control Consortium (INICC)

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    <p>Abstract</p> <p>Background</p> <p>Most studies related to healthcare-associated infection (HAI) were conducted in the developed countries. We sought to determine healthcare-associated infection rates, microbiological profile, bacterial resistance, length of stay (LOS), and extra mortality in one ICU of a hospital member of the International Infection Control Consortium (INICC) in Morocco.</p> <p>Methods</p> <p>We conducted prospective surveillance from 11/2004 to 4/2008 of HAI and determined monthly rates of central vascular catheter-associated bloodstream infection (CVC-BSI), catheter-associated urinary tract infection (CAUTI) and ventilator-associated pneumonia (VAP). CDC-NNIS definitions were applied. device-utilization rates were calculated by dividing the total number of device-days by the total number of patient-days. Rates of VAP, CVC-BSI, and CAUTI per 1000 Device-days were calculated by dividing the total number of HAI by the total number of specific Device-days and multiplying the result by 1000.</p> <p>Results</p> <p>1,731 patients hospitalized for 11,297 days acquired 251 HAIs, an overall rate of 14.5%, and 22.22 HAIs per 1,000 ICU-days. The central venous catheter-related bloodstream infections (CVC-BSI) rate found was 15.7 per 1000 catheter-days; the ventilator-associated pneumonia (VAP) rate found was 43.2 per 1,000 ventilator-days; and the catheter-associated urinary tract infections (CAUTI) rate found was 11.7 per 1,000 catheter-days.</p> <p>Overall 25.5% of all <it>Staphylococcus aureus </it>HAIs were caused by methicillin-resistant strains, 78.3% of <it>Coagulase-negative-staphylococci </it>were methicillin resistant as well. 75.0% of <it>Klebsiella </it>were resistant to ceftriaxone and 69.5% to ceftazidime. 31.9% of <it>E. Coli </it>were resistant to ceftriaxone and 21.7% to ceftazidime. 68.4% of <it>Enterobacter sp </it>were resistant to ceftriaxone, 55.6% to ceftazidime, and 10% to imipenem; 35.6% of <it>Pseudomonas sp </it>were resistant to ceftazidime and 13.5% to imipenem.</p> <p>LOS of patients was 5.1 days for those without HAI, 9.0 days for those with CVC-BSI, 10.6 days for those with VAP, and 13.7 days for those with CAUTI.</p> <p>Extra mortality was 56.7% (RR, 3.28; P =< 0.001) for VAP, 75.1% (RR, 4.02; P = 0.0027) for CVC-BSI, and 18.7% (RR, 1.75; P = 0.0218) for CAUTI.</p> <p>Conclusion</p> <p>HAI rates, LOS, mortality, and bacterial resistance were high. Even if data may not reflect accurately the clinical setting of the country, programs including surveillance, infection control, and antibiotic policy are a priority in Morocco.</p

    Density reconstruction from biased tracers and its application to primordial non-Gaussianity

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    Large-scale Fourier modes of the cosmic density field are of great value for learning about cosmology because of their well-understood relationship to fluctuations in the early universe. However, cosmic variance generally limits the statistical precision that can be achieved when constraining model parameters using these modes as measured in galaxy surveys, and moreover, these modes are sometimes inaccessible due to observational systematics or foregrounds. For some applications, both limitations can be circumvented by reconstructing large-scale modes using the correlations they induce between smaller-scale modes of an observed tracer (such as galaxy positions). In this paper, we further develop a formalism for this reconstruction, using a quadratic estimator similar to the one used for lensing of the cosmic microwave background. We incorporate nonlinearities from gravity, nonlinear biasing, and local-type primordial non-Gaussianity, and verify that the estimator gives the expected results when applied to N-body simulations. We then carry out forecasts for several upcoming surveys, demonstrating that, when reconstructed modes are included alongside directly-observed tracer density modes, constraints on local primordial non-Gaussianity are generically tightened by tens of percents compared to standard single-tracer analyses. In certain cases, these improvements arise from cosmic variance cancellation, with reconstructed modes taking the place of modes of a separate tracer, thus enabling an effective "multitracer" approach with single-tracer observations.Comment: 30 pages plus 14 pages appendices, 19 figure

    On the global well-posedness of a class of Boussinesq- Navier-Stokes systems

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    In this paper we consider the following 2D Boussinesq-Navier-Stokes systems \partial_{t}u+u\cdot\nabla u+\nabla p+ |D|^{\alpha}u &= \theta e_{2} \partial_{t}\theta+u\cdot\nabla \theta+ |D|^{\beta}\theta &=0 \quad with divu=0\textrm{div} u=0 and 0<β<α<10<\beta<\alpha<1. When 664<α<1\frac{6-\sqrt{6}}{4}<\alpha< 1, 1α<βf(α)1-\alpha<\beta\leq f(\alpha) , where f(α)f(\alpha) is an explicit function as a technical bound, we prove global well-posedness results for rough initial data.Comment: 23page
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