8,853 research outputs found

    Neutrino-nucleus interaction rates at a low-energy beta-beam facility

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    We compute the neutrino detection rates to be expected at a low-energy beta-beam facility. We consider various nuclei as neutrino detectors and compare the case of a small versus large storage ring.Comment: 6 pages, 3 figure

    SARS-CoV-2 and interferon blockade

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    © 2020, The Author(s). The response to viral infection generally includes an activation of the adaptive immune response to produce cytotoxic T cells and neutralizing antibodies. We propose that SARS-CoV-2 activates the innate immune system through the renin-angiotensin and kallikrein-bradykinin pathways, blocks interferon production and reduces an effective adaptive immune response. This model has therapeutic implications

    Low energy neutrino scattering measurements at future Spallation Source facilities

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    In the future several Spallation Source facilities will be available worldwide. Spallation Sources produce large amount of neutrinos from decay-at-rest muons and thus can be well adapted to accommodate state-of-the-art neutrino experiments. In this paper low energy neutrino scattering experiments that can be performed at such facilities are reviewed. Estimation of expected event rates are given for several nuclei, electrons and protons at a detector located close to the source. A neutrino program at Spallation Sources comprises neutrino-nucleus cross section measurements relevant for neutrino and core-collapse supernova physics, electroweak tests and lepton-flavor violation searches.Comment: 12 pages, 4 figures, 5 table

    Prenatal visualisation of the torcular herophili by means of a Doppler technology highly sensitive for low-velocity flow in the expert assessment of the posterior fossa: a prospective study

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    Objective: To evaluate the usefulness of a Doppler technology highly sensitive for low-velocity flow in the antenatal imaging of the torcular herophili (TH) in the second trimester of pregnancy. Design: Prospective study. Setting: Referral Fetal Medicine Unit. Population: Non-consecutive series of singleton pregnancies submitted to antenatal neurosonogram between 20 and 28 weeks of gestation. Methods: A midsagittal section of the fetal brain was obtained by insonating through the anterior fontanelle, then the MV-Flow™ and LumiFlow™ presets were selected to visualise the TH as the posterior confluence of the superior sagittal sinus and the straight sinus. Main outcome measures: Evaluation of the anatomic relationship of the TH with the ‘transpalatal line’ joining the upper bony palate to the fetal skull. Results: A total of 99 pregnant women were recruited, including one fetus with open spina bifida, one with Dandy–Walker malformation (DWM) and two with Blake's pouch cysts. In normal fetuses, the TH appeared to lie on or just below the ‘transpalatal line’. In the cases of Blake's pouch cyst, the position of the TH appeared normal if compared with controls, whereas in DWM a supra-elevated position of the TH in respect of the transpalatal line was demonstrated. Finally, in the fetus with Chiari II malformation the TH was identified below the ‘transpalatal plane’. Conclusions: Prenatal ultrasound visualisation of the TH by means of newly developed Doppler technologies characterised by high sensitivity for low-velocity flow is feasible and allows the indirect evaluation of the insertion of cerebellar tentorium in the second trimester. Tweetable abstract: Prenatal imaging of the torcular herophili using a Doppler technology highly sensitive for low-velocity flow

    Brain metabolism and autoantibody titres predict functional impairment in systemic lupus erythematosus

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    OBJECTIVE: We investigated whether systemic lupus erythematosus (SLE) disease duration or serology associate with abnormal regional glucose metabolism as measured with [(18)F]2-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) and deficits on neuropsychological testing. METHODS: Subjects with SLE with stable disease activity, without brain damage or clinical symptoms of neuropsychiatric (NP) SLE, stratified by disease duration (short-term (ST)-SLE=disease/=10 years), underwent clinical assessments, neuropsychological testing, resting FDG-PET scan imaging and measurement of serum titres of antibody to N-methyl-d-aspartate receptor (DNRAb). FDG-PET scans were compared with age-matched and gender-matched healthy controls. RESULTS: Subjects with LT-SLE demonstrated hypometabolism in the prefrontal and premotor cortices that correlated with accrued SLE-related damage, but not with DNRAb titre or performance on NP testing. Independent of disease duration, subjects with SLE demonstrated hypermetabolism in the hippocampus and orbitofrontal cortex that correlated with impaired memory performance and mood alterations (depression, anxiety, fatigue). Serum DNRAb also correlated independently with impaired memory performance and increased anxiety. Together, serum DNRAb titre and regional hypermetabolism were more powerful predictors of performance than either alone. INTERPRETATION: The presence of serum DNRAbs can account for some aspects of brain dysfunction in patients with SLE, and the addition of regional measurements of resting brain metabolism improves the assessment and precise attribution of central nervous system manifestations related to SLE

    Anharmonicities of giant dipole excitations

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    The role of anharmonic effects on the excitation of the double giant dipole resonance is investigated in a simple macroscopic model.Perturbation theory is used to find energies and wave functions of the anharmonic ascillator.The cross sections for the electromagnetic excitation of the one- and two-phonon giant dipole resonances in energetic heavy-ion collisions are then evaluated through a semiclassical coupled-channel calculation.It is argued that the variations of the strength of the anharmonic potential should be combined with appropriate changes in the oscillator frequency,in order to keep the giant dipole resonance energy consistent with the experimental value.When this is taken into account,the effects of anharmonicities on the double giant dipole resonance excitation probabilities are small and cannot account for the well-known discrepancy between theory and experiment
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