The cosmic ray shadow of the Moon observed with the ANTARES neutrino telescope

One of the main objectives of the ANTARES telescope is the search for point-like neutrino sources. Both the pointing accuracy and the angular resolution of the detector are important in this context and a reliable way to evaluate this performance is needed. In order to measure the pointing accuracy of the detector, one possibility is to study the shadow of the Moon, i.e. the deficit of the atmospheric muon flux from the direction of the Moon induced by the absorption of cosmic rays. Analysing the data taken between 2007 and 2016, the Moon shadow is observed with 3.5 σ statistical significance. The detector angular resolution for downward-going muons is 0 . 73 ∘ ± 0 . 14 ∘ . The resulting pointing performance is consistent with the expectations. An independent check of the telescope pointing accuracy is realised with the data collected by a shower array detector onboard of a ship temporarily moving around the ANTARES location.

An algorithm for the reconstruction of high-energy neutrino-induced particle showers and its application to the ANTARES neutrino telescope

A novel algorithm to reconstruct neutrino-induced particle showers within the ANTARES neutrino telescope is presented. The method achieves a median angular resolution of [Formula: see text] for shower energies below 100 TeV. Applying this algorithm to 6 years of data taken with the ANTARES detector, 8 events with reconstructed shower energies above 10 TeV are observed. This is consistent with the expectation of about 5 events from atmospheric backgrounds, but also compatible with diffuse astrophysical flux measurements by the IceCube collaboration, from which 2-4 additional events are expected. A [Formula: see text] C.L. upper limit on the diffuse astrophysical neutrino flux with a value per neutrino flavour of [Formula: see text] is set, applicable to the energy range from 23 TeV to 7.8 PeV, assuming an unbroken [Formula: see text] spectrum and neutrino flavour equipartition at Earth.

Sperm whale long-range echolocation sounds revealed by ANTARES, a deep-sea neutrino telescope

Despite dedicated research has been carried out to adequately map the distribution of the sperm whale in the Mediterranean Sea, unlike other regions of the world, the species population status is still presently uncertain. The analysis of two years of continuous acoustic data provided by the ANTARES neutrino telescope revealed the year-round presence of sperm whales in the Ligurian Sea, probably associated with the availability of cephalopods in the region. The presence of the Ligurian Sea sperm whales was demonstrated through the real-time analysis of audio data streamed from a cabled-to-shore deep-sea observatory that allowed the hourly tracking of their long-range echolocation behaviour on the Internet. Interestingly, the same acoustic analysis indicated that the occurrence of surface shipping noise would apparently not condition the foraging behaviour of the sperm whale in the area, since shipping noise was almost always present when sperm whales were acoustically detected. The continuous presence of the sperm whale in the region confirms the ecological value of the Ligurian sea and the importance of ANTARES to help monitoring its ecosystems.

60Co aqueous speciation and pH effect on the adsorption behavior on inorganic materials

The adsorption of radioactive cobalt from aqueous solution on MgO, MnO(2), TiO(2), SnO, activated carbon and calcined hydrotalcite was studied under static conditions as a function of pH (1, 3, 5, 7, and 10) of the (60)Co solution. It was found that under the experimental conditions, (60)Co was significantly adsorbed on MnO(2), TiO(2) and activated carbon and in smaller quantities on MgO, SnO and calcined hydrotalcite. The adsorption of (60)Co species on MgO, MnO(2), TiO(2) and SnO can be attributed to the direct exchange of ions with a specific group on the adsorbing surface, in accordance with the concept of zero point charge (zpc). The radionuclide content was determined by gamma-spectrometry. The (60)Co chemical species present in aqueous solutions with different pH values were surveyed by using high-voltage electrophoresis. It was also found that (60)Co was present only as a cationic species at pH 1, 3, 5 and 7 and a neutral species at alkaline pH.

Ab initio multireference configuration-interaction study of hydrogen molecule activation by Cs-promoted Pt clusters

The adsorption of the H2 molecule on CsnPt(5-n) bcc (111) clusters for Cs/Pt rates of 20%, 40%, and 80% is studied using ab initio multiconfigurational self-consistent field plus multireference configuration-interaction variational and perturbative calculations. The H2 interaction with the clusters is studied in ground and excited states with geometry optimization, where the hydrogen adsorption takes place by a Pt atom. These calculations are compared with those of H2 adsorption on Pt4. The most stable configurations of Cs/Pt4 and Cs2Pt3 clusters (Cs/Pt rates of 20% and 40%) are a doublet and a closed-shell singlet, respectively. Both clusters capture and activate the hydrogen molecule and their behaviors resemble Pt4. The H2 capture distances are, respectively, similar and smaller than Pt4 capture distances, while the H-H bond dissociation distances are similar and bigger than those of Pt4; however, none of them presents activation barriers. The most stable Cs4Pt cluster (Cs/Pt rate of 80%) is also a closed-shell singlet; it also captures and activates the hydrogen molecule and shows a different behavior as compared with Cs/Pt4, Cs2Pt3, and Pt4 clusters. The capture distance is quite smaller and is obtained after surmounting an activation barrier. For all clusters studied here, no hydrogen absorption was observed, only the adsorption of H2.

Theoretical study of the H2 reaction with a Pt4 (111) cluster

The C(s) symmetry reaction of the H(2) molecule on a Pt(4) (111) clusters, has been studied using ab initio multiconfiguration self-consistent field plus extensive multireference configuration interaction variational and perturbative calculations. The H(2) interaction by the vertex and by the base of a tetrahedral Pt(4) cluster were studied in ground and excited triplet and singlet states (closed and open shells), where the reaction curves are obtained through many avoided crossings. The Pt(4) cluster captures and activates the hydrogen molecule; it shows a similar behavior compared with other Pt(n) (n=1,2,3) systems. The Pt(4) cluster in their lowest five open and closed shell electronic states: (3)B(2), (1)B(2), (1)A(1) (3)A(1), (1)A(1), respectively, may capture and dissociate the H(2) molecule without activation barriers for the hydrogen molecule vertex approach. For the threefolded site reaction, i.e., by the base, the situation is different, the hydrogen adsorption presents some barriers. The potential energy minima occur outside and inside the cluster, with strong activation of the H-H bond. In all cases studied, the Pt(4) cluster does not absorb the hydrogen molecule.

Limbal conjunctival Langerhans cell density in ocular cicatricial pemphigoid: an indirect immunofluorescence study on Dispase-split conjunctiva

PURPOSE

To evaluate limbal conjunctival Langerhans cell density in ocular cicatricial pemphigoid patients versus normal controls. Langerhans cells obviously play a major role in T-cell activation and are involved in corneal and conjunctival inflammatory diseases.

METHODS

We used a protease (Dispase II) on inferior limbal conjunctival biopsies to separate the epithelium from the substantia propria and performed indirect immunofluorescence to analyze CD1a+ (a specific Langerhans cell surface antigen) cell density on flat-mounted epithelial sheets obtained from 30 normal controls and 11 patients presenting with ocular cicatricial pemphigoid.

RESULTS

This technique was quick and reproducible. The mean Langerhans cell density in normal limbal conjunctiva was 272 +/- 37 cells/mm2. It was significantly higher in ocular cicatricial pemphigoid patients: 386 +/- 43 cells/mm2 (p = 0.001).

CONCLUSIONS

Conjunctival Langerhans cell density in ocular surface inflammatory diseases can best be evaluated by indirect immunofluorescence, following epithelial sheet separation from the substantia propria, using Dispase II.

Evaluation of the Tono-Pen 2 and the X-Pert noncontact tonometers in cataract surgery

The Oculab Tono-Pen and the X-Pert noncontact tonometers (NCTs) were compared to the Goldmann applanation tonometer in a consecutive series of 45 patients before and after cataract surgery. In the preoperative period, the mean value of the paired difference at intraocular pressure (IOP) measurements was -1.30 +/- 2.11 mm Hg (mean +/- SD) for the X-Pert NCT (X-Pert NCT minus Goldmann) and -0.19 +/- 2.56 mm Hg for the Tono-Pen 2 (Tono-Pen 2 minus Goldmann). In the postoperative period, this mean difference was 0.26 +/- 2.45 mm Hg for the X-Pert NCT and 0.87 +/- 2.83 mm Hg for the Tono-Pen 2. We found 87 and 67% of the X-Pert NCT and the Tono-Pen 2 readings to be within +/- 2 mm Hg of the Goldmann readings, respectively. In both preoperative and postoperative eyes, correlation coefficients between the readings of the three instruments were high (ranging from 0.84 to 0.96). Differences between the three tonometers were not correlated with corneal thickness of corneal curvature postoperatively. Both Tono-Pen 2 and X-Pert NCT could thus be considered accurate instruments for IOP screening after cataract surgery when compared to the Goldmann applanation tonometer.