Saturn's icy satellites and rings investigated by Cassini - VIMS. III. Radial compositional variability

In the last few years Cassini-VIMS, the Visible and Infared Mapping Spectrometer, returned to us a comprehensive view of the Saturn's icy satellites and rings. After having analyzed the satellites' spectral properties (Filacchione et al. (2007a)) and their distribution across the satellites' hemispheres (Filacchione et al. (2010)), we proceed in this paper to investigate the radial variability of icy satellites (principal and minor) and main rings average spectral properties. This analysis is done by using 2,264 disk-integrated observations of the satellites and a 12x700 pixels-wide rings radial mosaic acquired with a spatial resolution of about 125 km/pixel. The comparative analysis of these data allows us to retrieve the amount of both water ice and red contaminant materials distributed across Saturn's system and the typical surface regolith grain sizes. These measurements highlight very striking differences in the population here analyzed, which vary from the almost uncontaminated and water ice-rich surfaces of Enceladus and Calypso to the metal/organic-rich and red surfaces of Iapetus' leading hemisphere and Phoebe. Rings spectra appear more red than the icy satellites in the visible range but show more intense 1.5-2.0 micron band depths. The correlations among spectral slopes, band depths, visual albedo and phase permit us to cluster the saturnian population in different spectral classes which are detected not only among the principal satellites and rings but among co-orbital minor moons as well. Finally, we have applied Hapke's theory to retrieve the best spectral fits to Saturn's inner regular satellites using the same methodology applied previously for Rhea data discussed in Ciarniello et al. (2011).Comment: 44 pages, 27 figures, 7 tables. Submitted to Icaru

Martian CO₂ Ice Observation at High Spectral Resolution With ExoMars/TGO NOMAD

The Nadir and Occultation for MArs Discovery (NOMAD) instrument suite aboard ExoMars/Trace Gas Orbiter spacecraft is mainly conceived for the study of minor atmospheric species, but it also offers the opportunity to investigate surface composition and aerosols properties. We investigate the information content of the Limb, Nadir, and Occultation (LNO) infrared channel of NOMAD and demonstrate how spectral orders 169, 189, and 190 can be exploited to detect surface CO2 ice. We study the strong CO2 ice absorption band at 2.7 μm and the shallower band at 2.35 μm taking advantage of observations across Martian Years 34 and 35 (March 2018 to February 2020), straddling a global dust storm. We obtain latitudinal‐seasonal maps for CO2 ice in both polar regions, in overall agreement with predictions by a general climate model and with the Mars Express/OMEGA spectrometer Martian Years 27 and 28 observations. We find that the narrow 2.35 μm absorption band, spectrally well covered by LNO order 189, offers the most promising potential for the retrieval of CO2 ice microphysical properties. Occurrences of CO2 ice spectra are also detected at low latitudes and we discuss about their interpretation as daytime high altitude CO2 ice clouds as opposed to surface frost. We find that the clouds hypothesis is preferable on the basis of surface temperature, local time and grain size considerations, resulting in the first detection of CO2 ice clouds through the study of this spectral range. Through radiative transfer considerations on these detections we find that the 2.35 μm absorption feature of CO2 ice clouds is possibly sensitive to nm‐sized ice grains

Evidence for transient morning water frost deposits on the Tharsis volcanoes of Mars

The present-day water cycle on Mars has implications for habitability and future human exploration. Water ice clouds and water vapour have been detected above the Tharsis volcanic province, suggesting the active exchange of water between regolith and atmosphere. Here we report observational evidence for extensive transient morning frost deposits on the calderas of the Tharsis volcanoes (Olympus, Arsia and Ascraeus Montes, and Ceraunius Tholus) using high-resolution colour images from the Colour and Stereo Surface Imaging System on board the European Space Agency’s Trace Gas Orbiter. The transient bluish deposits appear on the caldera floor and rim in the morning during the colder Martian seasons but are not present by afternoon. The presence of water frost is supported by spectral observations, as well as independent imagery from the European Space Agency’s Mars Express orbiter. Climate model simulations further suggest that early-morning surface temperatures at the high altitudes of the volcano calderas are sufficiently low to support the daily condensation of water—but not CO2 —frost. Given the unlikely seasonal nature of volcanic outgassing, we suggest the observed frost is atmospheric in origin, implying the role of microclimate in local frost formation and a contribution to the broader Mars water cycle

L'Italia come modello per l'Europa e per il mondo nelle politiche sanitarie per il trattamento dell'epatite cronica da HCV

The World Health Organization foresees the elimination of HCV infection by 2030. In light of this and the curre nt, nearly worldwide, restriction in direct-acting agents (DAA) accessibility due to their high price, we aimed to evaluate the cost-effectiveness of two alternative DAA treatment policies: Policy 1 (universal): treat all patients, regardless of the fibrosis stage; Policy 2 (prioritized): treat only priori tized patients and delay treatment of the remaining patients until reaching stage F3. T he model was based on patient’s data from the PITER cohort. We demonstrated that extending HC V treatment of patients in any fibrosis stage improves health outcomes and is cost-effective

Non-invasive prenatal detection of beta-thalassemia mutations in maternal plasma using Droplet Digital PCR

Non-invasive prenatal testing (NIPT) is based on fetal DNA analysis with the aim to identify genetic abnormalities from the maternal plasma during pregnancy1. Actually, commercial NIPT kits can detect only aneuploidies, small deletions or insertions but not single point mutations causing genetic diseases

Up-regulation of miR-34a-3p and miR-744-3p is associated with down-regulation of PTEN in lymphoblastoid cells from Shwachman-Diamond Syndrome patients

Shwachman-Diamond syndrome (SDS) is an inherited disease caused by mutations of a gene encoding for SBDS protein