1,373 research outputs found

    Secondary Haemorrhage Complicating Methicillin-resistant Staphylococcus aureus Infection in a Popliteal to Posterior Tibial Bypass Graft. A Role for Free Flaps?

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    Analiza la información sobre las fronteras con Colombia en los seis diarios de mayor circulación nacional (Extra, El Universo, El Comercio, La Hora, El Telégrafo y Hoy). Este análisis parte de una metodología que incluye una base de datos en la que se registran las noticias sobre frontera y las particularidades de cada cobertura, además de un trazado de áreas temáticas para organizar la diversidad de la información que publican al respecto los medios gráficos. Deslindes indaga en la construcción de un discurso mediático sobre una frontera que reconocemos como heterogénea, diversa y compleja. Es por ello que hemos preferido referirnos a las “fronteras”. Deslindes. Las fronteras en la prensa escrita es un proyecto del Centro de Prospectiva Estratégica del Instituto de Altos Estudios Nacionales (IAEN).I. Panorama semanal II. Cifras sobre la representación de fronteras III. Cobertura de la semana: Información sobre fuga de azúcar con una mirada restringida IV. Conclusione

    Random close packing of granular matter

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    We propose an interpretation of the random close packing of granular materials as a phase transition, and discuss the possibility of experimental verification.Comment: 6 page

    High-resolution radiation mapping to investigate FDNPP derived contaminant migration

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    AbstractAs of March 2016, five years will have passed since the earthquake and ensuing tsunami that crippled the Fukushima Daiichi Nuclear Power Plant on Japan’s eastern coast, resulting in the explosive release of significant quantities of radioactive material. Over this period, significant time and resource has been expended on both the study of the contamination as well as its remediation from the affected environments. Presented in this work is a high-spatial resolution foot-based radiation mapping study using gamma-spectrometry at a site in the contaminated Iitate Village; conducted at different times, seventeen months apart. The specific site selected for this work was one in which consistent uniform agriculture was observed across its entire extent. From these surveys, obtained from along the main northwest trending line of the fallout plume, it was possible to determine the rate of reduction in the levels of contamination around the site attributable to the natural decay of the radiocesium, remediation efforts or material transport. Results from the work suggest that neither the natural decay of radiocesium nor its downward migration through the soil horizons were responsible for the decline in measured activity levels across the site, with the mobilisation of contaminant species likely adhered to soil particulate and the subsequent fluvial transport responsible for the measurable reduction in activity. This transport of contaminant via fluvial methods has already well studied implications for the input of contaminant material entering the neighbouring Pacific Ocean, as well as the deposition of material along rivers within previously decontaminated areas

    Imperfect Detectors in Linear Optical Quantum Computers

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    We discuss the effects of imperfect photon detectors suffering from loss and noise on the reliability of linear optical quantum computers. We show that for a given detector efficiency, there is a maximum achievable success probability, and that increasing the number of ancillary photons and detectors used for one controlled sign flip gate beyond a critical point will decrease the probability that the computer will function correctly. We have also performed simulations of some small logic gates and estimate the efficiency and noise levels required for the linear optical quantum computer to function properly.Comment: 13 pages, 5 figure

    Transient thermal characterization of suspended monolayer MoS2_2

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    We measure the thermal time constants of suspended single layer molybdenum disulfide drums by their thermomechanical response to a high-frequency modulated laser. From this measurement the thermal diffusivity of single layer MoS2_2 is found to be 1.14 ×\times 105^{-5} m2^2/s on average. Using a model for the thermal time constants and a model assuming continuum heat transport, we extract thermal conductivities at room temperature between 10 to 40 W/(m\cdotK). Significant device-to-device variation in the thermal diffusivity is observed. Based on statistical analysis we conclude that these variations in thermal diffusivity are caused by microscopic defects that have a large impact on phonon scattering, but do not affect the resonance frequency and damping of the membrane's lowest eigenmode. By combining the experimental thermal diffusivity with literature values of the thermal conductivity, a method is presented to determine the specific heat of suspended 2D materials, which is estimated to be 255 ±\pm 104 J/(kg\cdotK) for single layer MoS2_2

    Protection against neonatal respiratory viral infection via maternal treatment during pregnancy with the benign immune training agent OM‐85

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    Objectives Incomplete maturation of immune regulatory functions at birth is antecedent to the heightened risk for severe respiratory infections during infancy. Our forerunner animal model studies demonstrated that maternal treatment with the microbial-derived immune training agent OM-85 during pregnancy promotes accelerated postnatal maturation of mechanisms that regulate inflammatory processes in the offspring airways. Here, we aimed to provide proof of concept for a novel solution to reduce the burden and potential long-term sequelae of severe early-life respiratory viral infection through maternal oral treatment during pregnancy with OM-85, already in widespread human clinical use. Methods In this study, we performed flow cytometry and targeted gene expression (RT-qPCR) analysis on lungs from neonatal offspring whose mothers received oral OM-85 treatment during pregnancy. We next determined whether neonatal offspring from OM-85 treated mothers demonstrate enhanced protection against lethal lower respiratory infection with mouse-adapted rhinovirus (vMC0), and associated lung immune changes. Results Offspring from mothers treated with OM-85 during pregnancy display accelerated postnatal seeding of lung myeloid populations demonstrating upregulation of function-associated markers. Offspring from OM-85 mothers additionally exhibit enhanced expression of TLR4/7 and the IL-1β/NLRP3 inflammasome complex within the lung. These treatment effects were associated with enhanced capacity to clear an otherwise lethal respiratory viral infection during the neonatal period, with concomitant regulation of viral-induced IFN response intensity. Conclusion These results demonstrate that maternal OM-85 treatment protects offspring against lethal neonatal respiratory viral infection by accelerating development of innate immune mechanisms crucial for maintenance of local immune homeostasis in the face of pathogen challenge

    In-situ removal and characterisation of uranium-containing particles from sediments surrounding the Fukushima Daiichi Nuclear Power Plant

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    AbstractTraditional methods to locate and subsequently study radioactive fallout particles have focused heavily on autoradiography coupled with in-situ analytical techniques. Presented here is the application of a Variable Pressure Scanning Electron Microscope with both backscattered electron and energy dispersive spectroscopy detectors, along with a micromanipulator setup and electron-hardening adhesive to isolate and remove individual particles before synchrotron radiation analysis. This system allows for a greater range of new and existing analytical techniques, at increased detail and speed, to be applied to the material. Using this method, it was possible to erform detailed energy dispersive spectroscopy and synchrotron radiation characterisation of material likely ejected from the Fukushima Daiichi Nuclear Power Plant found within a sediment sample collected from the edge of the 30km exclusion zone. Particulate material sub-micron in maximum dimension examined during this work via energy dispersive spectroscopy was observed to contain uranium at levels between 19.68 and 28.35 weight percent, with the application of synchrotron radiation spectroscopy confirming its presence as a major constituent.With great effort and cost being devoted to the remediation of significant areas of eastern Japan affected by the incident, it is crucial to gain the greatest possible understanding of the nature of this contamination in order to inform the most appropriate clean-up response

    Azimuthal Modulational Instability of Vortices in the Nonlinear Schr\"odinger Equation

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    We study the azimuthal modulational instability of vortices with different topological charges, in the focusing two-dimensional nonlinear Schr{\"o}dinger (NLS) equation. The method of studying the stability relies on freezing the radial direction in the Lagrangian functional of the NLS in order to form a quasi-one-dimensional azimuthal equation of motion, and then applying a stability analysis in Fourier space of the azimuthal modes. We formulate predictions of growth rates of individual modes and find that vortices are unstable below a critical azimuthal wave number. Steady state vortex solutions are found by first using a variational approach to obtain an asymptotic analytical ansatz, and then using it as an initial condition to a numerical optimization routine. The stability analysis predictions are corroborated by direct numerical simulations of the NLS. We briefly show how to extend the method to encompass nonlocal nonlinearities that tend to stabilize solutions.Comment: 8 pages, 6 figures, in press for Optics Communication

    Anomalies of ac driven solitary waves with internal modes: Nonparametric resonances induced by parametric forces

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    We study the dynamics of kinks in the ϕ4\phi^4 model subjected to a parametric ac force, both with and without damping, as a paradigm of solitary waves with internal modes. By using a collective coordinate approach, we find that the parametric force has a non-parametric effect on the kink motion. Specifically, we find that the internal mode leads to a resonance for frequencies of the parametric driving close to its own frequency, in which case the energy of the system grows as well as the width of the kink. These predictions of the collective coordinate theory are verified by numerical simulations of the full partial differential equation. We finally compare this kind of resonance with that obtained for non-parametric ac forces and conclude that the effect of ac drivings on solitary waves with internal modes is exactly the opposite of their character in the partial differential equation.Comment: To appear in Phys Rev
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