THE MERCURY ORBITER RADIO SCIENCE EXPERIMENT (MORE) ON-BOARD THE ESA/JAXA BEPICOLOMBO MISSION TO MERCURY

BepiColombo is a joint ESA/JAXA mission for a comprehensive exploration of the planet Mercury. The mission is now scheduled for launch in October 2018 and for orbit insertion at the end of 2025. The Mercury Orbiter Radio science Experiment (MORE) is one of the on-board experiments, devised to enable a better understanding of both Mercury geophysics and fundamental physics. The spacecraft will be equipped with full instrumentation able to perform very precise range and range-rate tracking from the Earth, on-board accelerometry and accurate angular observations by an optical on-board camera. This will give the chance to determine with very high accuracy the spacecraft orbit around Mercury and the orbit of Mercury around the Solar System barycenter, allowing to achieve the main scienti c goals, which are concerned with the gravity and rotation of Mercury and General Relativity (GR) tests. The global experiment consists of determining the value and the formal uncertainty of a number of parameters of general interest, as the spherical harmonics of Mercury gravity eld up to degree and order 25 and its temporal variations due to tides (gravimetry experiment) and the parameters de ning the rotation state of the planet (rotation experiment). Moreover, the accurate measurement of the orbit of Mercury and of the propagation of radio waves between Earth and Mercury will allow to test GR, constraining a number of post-Newtonian and related parameters and providing an improved dynamical model for the Solar System (relativity experiment). All the parameters of interest for the radio science experiment are determined simultaneously by means of a global least squares t, adopting a constrained multi-arc strategy. We present the results of a global numerical simulation of the experiment, carried out with the MORE dedicated software, ORBIT14, developed by the Celestial Mechanics Group of the University of Pisa under an Italian Space Agency commission. The software allows both for the generation of simulated observables and for the determination of the parameters and their uncertainties with a di erential corrections method. The simulation has been performed in a realistic up-to-date scenario, which includes the detrimental e ects in the parameters estimation due to the on-board accelerometer measurement errors and the support of the high-resolution observations from the on-board optical camera

High GADA titer increases the risk of insulin requirement in LADA patients: A 7-year follow-up (NIRAD study 7)

Objective: The aim of this study was to determine whether glutamic acid decarboxylase antibody (GADA) titer and other clinical parameters could define the risk of progression to insulin therapy in latent autoimmune diabetes in adults (LADA) patients during a 7-year follow-up. Methods: This study involved 220 LADA and 430 type 2 diabetes subjects followed up for 7 years from the time of GADA screening to evaluate their progression toward insulin therapy. Kaplan-Meier curves and multivariate logistic regression analysis were performed to identify the markers capable of influencing this progression. Results: During the follow-up, the drop out was 4% in both groups. A total of 119 (56.1%) out of 212 LADA patients required insulin during the 7 years of follow-up. The Kaplan-Meier plots showed that 74/104 (71.1%) of high GADA titer required insulin compared with 45/108 (41.6%) of low GADA titer and with 86/412 (20.9%) of type 2 diabetes ( P2 and IA-2IC and zinc transporter 8 (ZnT8) positivity were also shown as the markers of faster progression (PIC positivity and sulfonylurea treatment, in the first year from diagnosis, significantly increase the progression toward insulin requirement in LADA patients

Long-term temporal stability of the DarkSide-50 dark matter detector

International audienceThe stability of a dark matter detector on the timescale of a few years is a key requirement due to the large exposure needed to achieve a competitive sensitivity. It is especially crucial to enable the detector to potentially detect any annual event rate modulation, an expected dark matter signature. In this work, we present the performance history of the DarkSide-50 dual-phase argon time projection chamber over its almost three-year low-radioactivity argon run. In particular, we focus on the electroluminescence signal that enables sensitivity to sub-keV energy depositions. The stability of the electroluminescence yield is found to be better than 0.5%. Finally, we show the temporal evolution of the observed event rate around the sub-keV region being consistent to the background prediction