37,157 research outputs found

    Quantized vortices in two dimensional solid 4He

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    Diagonal and off-diagonal properties of 2D solid 4He systems doped with a quantized vortex have been investigated via the Shadow Path Integral Ground State method using the fixed-phase approach. The chosen approximate phase induces the standard Onsager-Feynman flow field. In this approximation the vortex acts as a static external potential and the resulting Hamiltonian can be treated exactly with Quantum Monte Carlo methods. The vortex core is found to sit in an interstitial site and a very weak relaxation of the lattice positions away from the vortex core position has been observed. Also other properties like Bragg peaks in the static structure factor or the behavior of vacancies are very little affected by the presence of the vortex. We have computed also the one-body density matrix in perfect and defected 4He crystals finding that the vortex has no sensible effect on the off-diagonal long range tail of the density matrix. Within the assumed Onsager Feynman phase, we find that a quantized vortex cannot auto-sustain itself unless a condensate is already present like when dislocations are present. It remains to be investigated if backflow can change this conclusion.Comment: 4 pages, 3 figures, LT26 proceedings, accepted for publication in Journal of Physics: Conference Serie

    Trichothecenes NIV and DON modulate the maturation of murinedendritic cells

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    Nivalenol (NIV) and Deoxynivalenol (DON), mycotoxins of the trichothecene family are considered very common food contaminants. In this work, we investigated whether the immunotoxic effects ascribed to these trichothecenes may be mediated by perturbations in the activity of dendritic cells (DCs). Murine bone marrow-derived DCs were used to evaluate the effects of NIV and DON on the LPS-induced maturation process.We found that the expression of the class II MHC and of the accessory CD11c molecules, but not of the costimulatory CD86 marker, was down-regulated by NIV and DON exposure in LPS-treated DCs, as well as nitric oxide (NO) production. Interestingly, NIV, but not DON, induced DC necrosis. Moreover, the analysis of the cytokine pattern showed that IL-12 and IL-10 expressions induced by LPS exposure were suppressed by both trichothecenes in a dose-dependent fashion. On the other hand, the secretion of the proinflammatory cytokine TNFa was increased as a direct consequence of DON and NIV exposure. Taken together, our data indicated that the immunotoxicity of NIV and DON was related to the capacity of both trichothecenes to interfere with phenotypic and functional features of maturing DCs

    Technical quality assessment of an optoelectronic system for movement analysis

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    The Optoelectronic Systems (OS) are largely used in gait analysis to evaluate the motor performances of healthy subjects and patients. The accuracy of marker trajectories reconstruction depends on several aspects: the number of cameras, the dimension and position of the calibration volume, and the chosen calibration procedure. In this paper we propose a methodology to evaluate the eects of the mentioned sources of error on the reconstruction of marker trajectories. The novel contribution of the present work consists in the dimension of the tested calibration volumes, which is comparable with the ones normally used in gait analysis; in addition, to simulate trajectories during clinical gait analysis, we provide non-default paths for markers as inputs. Several calibration procedures are implemented and the same trial is processed with each calibration le, also considering dierent cameras congurations. The RMSEs between the measured trajectories and the optimal ones are calculated for each comparison. To investigate the signicant dierences between the computed indices, an ANOVA analysis is implemented. The RMSE is sensible to the variations of the considered calibration volume and the camera congurations and it is always inferior to 43 mm

    The Rainbow Prim Algorithm for Selecting Putative Orthologous Protein Sequences

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    We present a selection method designed for eliminating species redundancy in clusters of putative orthologous sequences, to be applied as a post-processing procedure to pre-clustered data obtained from other methods. The algorithm can always zero-out the cluster redundancy while preserving the number of species of the original cluster

    Strong coupling expansion of chiral models

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    A general precedure is outlined for an algorithmic implementation of the strong coupling expansion of lattice chiral models on arbitrary lattices. A symbolic character expansion in terms of connected values of group integrals on skeleton diagrams may be obtained by a fully computerized approach.Comment: 2 pages, PostScript file, contribution to conference LATTICE '9

    MarsLux: HI-Resolution Illumination Maps Generator for Mars

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    Illumination simulation codes for the Moon's surface have been thoroughly developed during the last years. Despite works done for the Moon, no studies have investigated the relation between sunlight illumination and the Martian surface applying those codes done for the Moon to Mars. The objective of this work is to describe the development of a surface illumination simulation code, called MarsLux, which allows users to make a detailed investigation of the illumination conditions on Mars, based on its topography and the relative position of the Sun. Our code can derive accurate illumination maps, form topographic data, showing areas that are fully illuminated, areas in total shadow, and areas with partial shade, in short computational times. Although the code does not take into account any atmospheric effect, the results proved to be of high accuracy. The maps generated are useful for geomorphological studies, to study gullies, thermal weathering, or mass wasting processes as well as for producing energy budget maps for future exploration missions.Fil: Spagnuolo, Mauro Gabriel. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Carballo, Federico Daniel. Servicio Geologico Minero Argentino; ArgentinaFil: Marco Figuera, R.. Jacobs University Bremen; AlemaniaFil: Rossi, A. P.. Jacobs University Bremen; Alemani

    Screening for Infectious diseases among newly arrived migrants. experiences and practices in non-EU countries of the Mediterranean basin and Black Sea

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    Changing migration dynamics in the Mediterranean Sea and differences in infectious diseases (ID) burden between the countries of origin have raised questions whether public health actions are needed to avoid the transmission of ID. Screening newly arrived migrants for ID is one health monitoring option, offering opportunities for prevention, early detection and treatment. The authors conducted a survey among country experts in non-European Union countries of the Mediterranean and Black Sea, in order to explore current ID screening practices and policies for newly arrived migrants. The association between the existence of guidelines and the proportion of refugees in the population was also estimated. Eighteen country experts responded (90%) out of the 20 invited. Eleven countries (61%) implemented screening programmes and six (38%) had national guidelines. Screening was performed most often for tuberculosis at the holding level. A higher proportion of refugees in the population was associated with the existence of guidelines for screening (p = 0.05). Fourteen experts (88%) considered screening among migrants useful. The results show that screening for ID in newly arrived migrants is relevant for non-EU countries of the Mediterranean and Black Sea. Common guidelines could be promoted focusing on both individual and public health benefits of screening programmesChanging migration dynamics in the Mediterranean Sea and differences in infectious diseases (ID) burden between the countries of origin have raised questions whether public health actions are needed to avoid the transmission of ID. Screening newly arrived migrants for ID is one health monitoring option, offering opportunities for prevention, early detection and treatment. The authors conducted a survey among country experts in non-European Union countries of the Mediterranean and Black Sea, in order to explore current ID screening practices and policies for newly arrived migrants. The association between the existence of guidelines and the proportion of refugees in the population was also estimated. Eighteen country experts responded (90%) out of the 20 invited. Eleven countries (61%) implemented screening programmes and six (38%) had national guidelines. Screening was performed most often for tuberculosis at the holding level. A higher proportion of refugees in the population was associated with the existence of guidelines for screening (p = 0.05). Fourteen experts (88%) considered screening among migrants useful. The results show that screening for ID in newly arrived migrants is relevant for non-EU countries of the Mediterranean and Black Sea. Common guidelines could be promoted focusing on both individual and public health benefits of screening programmes
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