488 research outputs found

    (Down-to-)Earth matter effect in supernova neutrinos

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    Neutrino oscillations in the Earth matter may introduce peculiar modulations in the supernova (SN) neutrino spectra. The detection of this effect has been proposed as diagnostic tool for the neutrino mass hierarchy at "large" 1-3 leptonic mixing angle theta13. We perform an updated study on the observability of this effect at large next-generation underground detectors (i.e., 0.4 Mton water Cherenkov, 50 kton scintillation and 100 kton liquid Argon detectors) based on neutrino fluxes from state-of-the-art SN simulations and accounting for statistical fluctuations via Montecarlo simulations. Since the average energies predicted by recent simulations are lower than previously expected and a tendency towards the equalization of the neutrino fluxes appears during the SN cooling phase, the detection of the Earth matter effect will be more challenging than expected from previous studies. We find that none of the proposed detectors shall be able to detect the Earth modulation for the neutrino signal of a typical galactic SN at 10 kpc. It should be observable in a 100 kton liquid Argon detector for a SN at few kpc and all three detectors would clearly see the Earth signature for very close-by stars only (d ~ 0.2 kpc). Finally, we show that adopting IceCube as co-detector together with a Mton water Cherenkov detector is not a viable option either.Comment: (14 pages, 5 ps figures

    High Energy Neutrinos with a Mediterranean Neutrino Telescope

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    The high energy neutrino detection by a km^3 Neutrino Telescope placed in the Mediterranean sea provides a unique tool to both determine the diffuse astrophysical neutrino flux and the neutrino-nucleon cross section in the extreme kinematical region, which could unveil the presence of new physics. Here is performed a brief analysis of possible NEMO site performances.Comment: 4 pages, 3 figures, Proceedings of the 30th ICRC 200

    Disentangling neutrino-nucleon cross section and high energy neutrino flux with a km^3 neutrino telescope

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    The energy--zenith angular event distribution in a neutrino telescope provides a unique tool to determine at the same time the neutrino-nucleon cross section at extreme kinematical regions, and the high energy neutrino flux. By using a simple parametrization for fluxes and cross sections, we present a sensitivity analysis for the case of a km^3 neutrino telescope. In particular, we consider the specific case of an under-water Mediterranean telescope placed at the NEMO site, although most of our results also apply to an under-ice detector such as IceCube. We determine the sensitivity to departures from standard values of the cross sections above 1 PeV which can be probed independently from an a-priori knowledge of the normalization and energy dependence of the flux. We also stress that the capability to tag downgoing neutrino showers in the PeV range against the cosmic ray induced background of penetrating muons appears to be a crucial requirement to derive meaningful constraints on the cross section.Comment: 10 pages, 28 figure

    Phenomenological covariant approach to gravity

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    We covariantly modify the Einstein-Hilbert action such that the modified action perturbatively resolves the flat rotational velocity curve of the spiral galaxies and gives rise to the Tully-Fisher relation, and dynamically generates the cosmological constant. This modification requires introducing just a single new universal parameter.Comment: v6: a mistake in deriving the equation of the cosmological constant corrected, refs adde

    Sensitivity on Earth Core and Mantle densities using Atmospheric Neutrinos

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    Neutrino radiography may provide an alternative tool to study the very deep structures of the Earth. Though these measurements are unable to resolve the fine density layer features, nevertheless the information which can be obtained are independent and complementary to the more conventional seismic studies. The aim of this paper is to assess how well the core and mantle averaged densities can be reconstructed through atmospheric neutrino radiography. We find that about a 2% sensitivity for the mantle and 5% for the core could be achieved for a ten year data taking at an underwater km^3 Neutrino Telescope. This result does not take into account systematics related to the details of the experimental apparatus.Comment: 11 pages, 11 figures, accepted for publication in JCA

    Diagnostic performance of inflammatory biomarkers and cytological analysis in salivary gland tumors

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    Background: This study aimed to evaluate the diagnostic performance of serum inflammatory biomarkers in salivary gland tumors with dubious results following cytological analysis. Methods: A retrospective analysis of 239 cases following surgery between January 2011 and June 2022 was performed. Receiver Operating Characteristic curves were drawn and areas under the curves were computed to evaluate the diagnostic performance of the inflammatory biomarkers (SII, SIRI, PLR, and NLR). Optimal cut-offs for each marker were determined by maximizing the Youden index. Results: Analysis showed that among the major biomarkers examined, SIRI performed an AUC of 0.77. The best SIRI cut-off was 0.94 with an accuracy of 79.9%. The accuracy, sensitivity, and specificity of cytological analysis were 77.8%, 59.6%, and 90.7% respectively. By combining SIRI with cytological analysis we demonstrated an increase in sensitivity to 82.8%. Conclusions: Inflammatory biomarkers could be evaluated to support the diagnosis and treatment of salivary gland tumors in difficult cases

    Il sistema di monitoraggio sismico dell’Osservatorio Vesuviano – INGV

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    Obiettivo principale del monitoraggio dei vulcani attivi è individuare e misurare fenomeni che possono essere indotti dal movimento del magma in profondità. Dal punto di vista sismologico questi fenomeni possono essere sciami sismici, eventi a bassa frequenza, microtremore vulcanico ed eventi very long period (VLP). Attraverso la misura, l'analisi e la corretta interpretazione di questi fenomeni è possibile capire in anticipo se un vulcano sta evolvendo verso una ripresa dell'attività eruttiva. L'Osservatorio Vesuviano - INGV ha tra i suoi compiti istituzionali il monitoraggio del Vesuvio, dei Campi Flegrei e di Ischia che sono, come è noto, vulcani a alto rischio a causa del loro stile eruttivo prevalentemente esplosivo e della presenza nelle loro prossimità di vaste aree urbanizzate. Per effettuare il monitoraggio sismologico di dette aree l'Osservatorio Vesuviano ha sviluppato e mantiene una rete che trasmette i dati in continuo al centro di sorveglianza. La configurazione attuale della rete comprende 28 stazioni analogiche a corto periodo (1Hz) e 4 stazioni digitali a larga banda.PublishedRoma1.4. TTC - Sorveglianza sismologica delle aree vulcaniche attiveope

    Label-free fiber optic optrode for the detection of class C beta-lactamases expressed by drug resistant bacteria

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    This paper reports the experimental assessment of an automated optical assay based on label free optical fiber optrodes for the fast detection of class C beta-lactamases (AmpC BLs), actually considered as one of the most important sources of resistance to beta-lactams antibiotics expressed by resistant bacteria. Reflection-type long period fiber gratings (RT-LPG) have been used as highly sensitive label free optrodes, while a higher affine boronic acid based ligand was here selected to enhance the overall assay performances compared to those obtained in our first demonstration. In order to prove the feasibility analysis towards a fully automated optical assay, an engineered system was developed to simultaneously manipulate and interrogate multiple fiber optic optrodes in the different phases of the assay. The automated system tested in AmpC solutions at increasing concentrations demonstrated a limit of detection (LOD) of 6 nM, three times better when compared with the results obtained in our previous work. Moreover, the real effectiveness of the proposed optical assay has been also confirmed in complex matrices as the case of lysates of Escherichia coli overexpressing AmpC. (C) 2017 Optical Society of Americ
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