755 research outputs found

    Secondary radiation from the Pamela/ATIC excess and relevance for Fermi

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    The excess of electrons/positrons observed by the Pamela and ATIC experiments gives rise to a noticeable amount of synchrotron and Inverse Compton Scattering (ICS) radiation when the e^+e^- interact with the Galactic Magnetic Field, and the InterStellar Radiation Field (ISRF). In particular, the ICS signal produced within the WIMP annihilation interpretation of the Pamela/ATIC excess shows already some tension with the EGRET data. On the other hand, 1 yr of Fermi data taking will be enough to rule out or confirm this scenario with a high confidence level. The ICS radiation produces a peculiar and clean "ICS Haze" feature, as well, which can be used to discriminate between the astrophysical and Dark Matter scenarios. This ICS signature is very prominent even several degrees away from the galactic center, and it is thus a very robust prediction with respect to the choice of the DM profile and the uncertainties in the ISRF.Comment: 5 pages, 3 figures; v2: improved figures, enlarged discussion on the gamma signal and data; to appear in ApJ

    Ultrahigh energy neutrinos with a mediterranean neutrino telescope

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    A study of the ultra high energy neutrino detection performances of a km^3 Neutrino Telescope sitting at the three proposed sites for "ANTARES", "NEMO" and "NESTOR" in the Mediterranean sea is here performed. The detected charged leptons energy spectra, entangled with their arrival directions, provide an unique tool to both determine the neutrino flux and the neutrino-nucleon cross section.Comment: 10 pages, 10 figures, Proceedings of XII International Workshop on Neutrino Telescopes, Venezia 200

    Radio constraints on dark matter annihilation in the galactic halo and its substructures

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    Annihilation of Dark Matter usually produces together with gamma rays comparable amounts of electrons and positrons. The e+e- gyrating in the galactic magnetic field then produce secondary synchrotron radiation which thus provides an indirect mean to constrain the DM signal itself. To this purpose, we calculate the radio emission from the galactic halo as well as from its expected substructures and we then compare it with the measured diffuse radio background. We employ a multi-frequency approach using data in the relevant frequency range 100 MHz-100 GHz, as well as the WMAP Haze data at 23 GHz. The derived constraints are of the order =10^{-24} cm3 s^{-1} for a DM mass m_chi=100 GeV sensibly depending however on the astrophysical uncertainties, in particular on the assumption on the galactic magnetic field model. The signal from single bright clumps is instead largely attenuated by diffusion effects and offers only poor detection perspectives.Comment: 12 pages, 7 figures; v2: some references added, some discussions enlarged; matches journal versio

    Adnexal Torsion in Pediatric Age: Does Bolli's Score Work? Report of Two Cases

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    Adnexal torsion is a surgical emergency requiring early diagnosis in order to avoid demolitive surgery. Adnexal torsion's diagnosis could be very difficult in pediatric patients because children cannot explain symptoms accurately. Furthermore reproductive organs lie high in abdomen, causing unclear examinations findings. For reducing diagnostic mistakes or delay clinical and hematological criteria could be useful. No radiological criteria (CT or MRI) should be taken in count because of the costs and the required time. By combining clinical presentation in patients with OT three useful diagnostic variables have been identified: age, duration of pain, vomiting. Presence of vomiting, short duration of abdominal pain and high CRP levels have great predictive value for the diagnosis of adnexal torsion. In those patients an exploratory laparoscopy should be performed without any doubt and/or delay. These data may aid physicians in the evaluation of abdominal pain in premenarchal girls

    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

    SISTEMI DI TELECONTROLLO SU RETE ETHERNET EGSM PER STAZIONI SISMICHE

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    La gestione e la manutenzione di sistemi di monitoraggio remoti richiede notevole dispendio di risorse umane. La complessità dei sistemi utilizzati necessita di metodi di protezione hardware e software (watchdog) atti a limitare interferenze esterne quali sovratensioni sulle linee di segnale e di alimentazione o blocchi indesiderati. Può talvolta accadere che per cause impreviste, quali ad esempio scariche atmosferiche a breve distanza, i sistemi elettronici si pongano in una condizione di blocco, pur senza subire danni strutturali significativi. Tale situazione è spesso risolvibile con una procedura di spegnimento e successivo riavvio dei sistemi. Si comprende come tale semplice procedura richieda l’impiego di risorse nel caso di apparecchiature poste a grande distanza o in siti difficilmente raggiungibili in avverse condizioni meteorologiche , come i sistemi di monitoraggio della Rete sismica di Stromboli e alcune installazioni della Rete Sismica Vesuvio. Per minimizzare la necessità di tali interventi di manutenzione è stato realizzato un sistema di controllo remoto, che consente operazioni di comando e verifica a distanza. È possibile controllare qualsiasi tipo di dispositivo tramite rete ethernet. In alternativa a tale supporto è stato sviluppato un telecontrollo che utilizza la rete cellulare GSM. Il primo sistema utilizza la rete ethernet e consente un reset completo dei sistemi ad esso collegati. Anche il secondo permette di resettare i sistemi ad esso collegati, ma differisce dal primo sia per l’utilizzo della rete GSM che per la funzione che consente il monitoraggio h24 dell’alimentazione. Non sempre è presente la rete ethernet o una sufficiente copertura del segnale GSM in corrispondenza dei siti presso i quali sono effettuate installazioni; per tale motivo sono stati sviluppati sistemi che sfruttano mezzi di trasmissione diversi. Di seguito saranno descritti: 1. Sistema di telecontrollo su rete ethernet. 2. Sistema di telecontrollo su rete GSM

    Alopecia universalis occurring after alemtuzumab treatment for multiple sclerosis. A two-year follow-up of two patients

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    Alopecia Universalis (AU) is the most severe form of Alopecia Areata and is caused by cytotoxic T-cells reacting with follicular autoantigens, producing complete loss of scalp and body hair. Alemtuzumab is a highly efficacious monoclonal antibody used in the treatment of Multiple Sclerosis (MS), but it causes secondary autoimmunity in up to 40% of patients. Many factors are believed to contribute to this process, but pathogenic mechanisms are not well clear. To date, three cases of AU after treatment with Alemtuzumab have been reported. In this paper we report the cases of two patients who developed AU 12 months after the second cycle of Alemtuzumab, with a review of the literature. One year after the end of the second cycle, two female patients in their thirties experienced complete hair loss. The first case was temporally associated with a significant drop in vitamin D (VD) levels. The second case was accompanied by joint swelling. Both patients had thyroid alterations and showed no hair regrowth after a 2-year follow-up. AU must be considered among the secondary autoimmune manifestations of Alemtuzumab treatment. We emphasize the need for appropriate patient screening and thorough clinical surveillance for factors predisposing patients to secondary autoimmunity

    (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
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