177 research outputs found

    CEUS: What is its role in abdominal aortic diseases?

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    GIS-Based Model for Constructing Ecological Efficiency Maps of Urban Green Areas: The Case Study of Western Naples, Italy

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    This research implements a GIS framework model aimed at evaluating the ecological efficiency of urban green areas. The model classifies urban green areas by identifying those that can provide ecosystem services to sustain green infrastructure at an urban district level. This model can also guide decision makers in the proper placement of the green infrastructure. The model works on the interrelation of four indicators of size, shape, vegetation structure and vegetation diversity, and it was tested in the case study of the Western Urban Districts of Naples (Italy). The selection of this study area is because it presents four urban districts that are different for physiography, urban patterns, land use, land cover and for the existing building stock. The proposed GIS-based framework can be a useful tool for planning actions and measures to protect, implement and restore existing green areas through integration into urban green infrastructure

    Cone beam computed tomography after round window vibroplasty. do the radiological findings match the auditory outcome?

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    Conclusion: The CBCT imaging technique has proved to be reliable for assessing the appropriate positioning of the FMT in the round window niche. However, when considering specific imaging parameters, such as lack of bony contacts and appropriate inferior support, they would not seem essential for achieving a satisfactory functional outcome. Objectives: To evaluate the value of some imaging parameters derived from a Cone Beam Computed Tomography of the temporal bone for predicting a good functional outcome after Round Window Vibroplasty (RW-VP). Method: A CBCT imaging has been carried out at certain time after RW-VP surgery in a homogenous group of patients who presented with a mixed-type hearing loss after open tympanoplasty for a cholesteatoma. Three arbitrary radiological parameters have been considered for the purpose: the FMT/RW membrane contact; eventual FMT bony contacts; appropriatmess of inferior FMT support. The audiological assessment has taken into consideration the PTA4 (500-4000 Hertz), the PTA2 (125.250 Hertz), the WRS in quiet and in noise (SNR=+10). A comparison between the unaided and the RW-VP aided condition has been performed

    Search for spontaneous muon emission from lead nuclei

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    We describe a possible search for muonic radioactivity from lead nuclei using the base elements ("bricks" composed by lead and nuclear emulsion sheets) of the long-baseline OPERA neutrino experiment. We present the results of a Monte Carlo simulation concerning the expected event topologies and estimates of the background events. Using few bricks, we could reach a good sensitivity level.Comment: 12 pages, 4 figure

    Electron/pion separation with an Emulsion Cloud Chamber by using a Neural Network

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    We have studied the performance of a new algorithm for electron/pion separation in an Emulsion Cloud Chamber (ECC) made of lead and nuclear emulsion films. The software for separation consists of two parts: a shower reconstruction algorithm and a Neural Network that assigns to each reconstructed shower the probability to be an electron or a pion. The performance has been studied for the ECC of the OPERA experiment [1]. The e/πe/\pi separation algorithm has been optimized by using a detailed Monte Carlo simulation of the ECC and tested on real data taken at CERN (pion beams) and at DESY (electron beams). The algorithm allows to achieve a 90% electron identification efficiency with a pion misidentification smaller than 1% for energies higher than 2 GeV

    Determination of the muon charge sign with the dipolar spectrometers of the OPERA experiment

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    The OPERA long-baseline neutrino-oscillation experiment has observed the direct appearance of ντ\nu_\tau in the CNGS νμ\nu_\mu beam. Two large muon magnetic spectrometers are used to identify muons produced in the τ\tau leptonic decay and in νμCC\nu_\mu^{CC} interactions by measuring their charge and momentum. Besides the kinematic analysis of the τ\tau decays, background resulting from the decay of charmed particles produced in νμCC\nu_\mu^{CC} interactions is reduced by efficiently identifying the muon track. A new method for the charge sign determination has been applied, via a weighted angular matching of the straight track-segments reconstructed in the different parts of the dipole magnets. Results obtained for Monte Carlo and real data are presented. Comparison with a method where no matching is used shows a significant reduction of up to 40\% of the fraction of wrongly determined charges.Comment: 10 pages. Improvements in the tex

    Procedure for short-lived particle detection in the OPERA experiment and its application to charm decays

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    The OPERA experiment, designed to perform the first observation of νμντ\nu_\mu \rightarrow \nu_\tau oscillations in appearance mode through the detection of the τ\tau leptons produced in ντ\nu_\tau charged current interactions, has collected data from 2008 to 2012. In the present paper, the procedure developed to detect τ\tau particle decays, occurring over distances of the order of 1 mm from the neutrino interaction point, is described in detail. The results of its application to the search for charmed hadrons are then presented as a validation of the methods for ντ\nu_\tau appearance detection

    Limits on muon-neutrino to tau-neutrino oscillations induced by a sterile neutrino state obtained by OPERA at the CNGS beam

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    The OPERA experiment, exposed to the CERN to Gran Sasso νμ\nu_\mu beam, collected data from 2008 to 2012. Four oscillated ντ\nu_\tau Charged Current interaction candidates have been detected in appearance mode, which are consistent with νμντ\nu_\mu \to \nu_\tau oscillations at the atmospheric Δm2\Delta m^2 within the "standard" three-neutrino framework. In this paper, the OPERA ντ\nu_\tau appearance results are used to derive limits on the mixing parameters of a massive sterile neutrino.Comment: 11 pages, 4 figures; reference to Planck result updated in the Introduction. Submitted to JHE

    Observation of nu_tau appearance in the CNGS beam with the OPERA experiment

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    The OPERA experiment is searching for nu_mu -> nu_tau oscillations in appearance mode i.e. via the direct detection of tau leptons in nu_tau charged current interactions. The evidence of nu_mu -> nu_tau appearance has been previously reported with three nu_tau candidate events using a sub-sample of data from the 2008-2012 runs. We report here a fourth nu_tau candidate event, with the tau decaying into a hadron, found after adding the 2012 run events without any muon in the final state to the data sample. Given the number of analysed events and the low background, nu_mu -> nu_tau oscillations are established with a significance of 4.2sigma.Comment: Submitted to Progress of Theoretical and Experimental Physics (PTEP

    Emulsion sheet doublets as interface trackers for the OPERA experiment

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    New methods for efficient and unambiguous interconnection between electronic counters and target units based on nuclear photographic emulsion films have been developed. The application to the OPERA experiment, that aims at detecting oscillations between mu neutrino and tau neutrino in the CNGS neutrino beam, is reported in this paper. In order to reduce background due to latent tracks collected before installation in the detector, on-site large-scale treatments of the emulsions ("refreshing") have been applied. Changeable Sheet (CSd) packages, each made of a doublet of emulsion films, have been designed, assembled and coupled to the OPERA target units ("ECC bricks"). A device has been built to print X-ray spots for accurate interconnection both within the CSd and between the CSd and the related ECC brick. Sample emulsion films have been extensively scanned with state-of-the-art automated optical microscopes. Efficient track-matching and powerful background rejection have been achieved in tests with electronically tagged penetrating muons. Further improvement of in-doublet film alignment was obtained by matching the pattern of low-energy electron tracks. The commissioning of the overall OPERA alignment procedure is in progress.Comment: 19 pages, 19 figure
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