199 research outputs found

    EChO Payload electronics architecture and SW design

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    EChO is a three-modules (VNIR, SWIR, MWIR), highly integrated spectrometer, covering the wavelength range from 0.55 Ό\mum, to 11.0 Ό\mum. The baseline design includes the goal wavelength extension to 0.4 Ό\mum while an optional LWIR module extends the range to the goal wavelength of 16.0 Ό\mum. An Instrument Control Unit (ICU) is foreseen as the main electronic subsystem interfacing the spacecraft and collecting data from all the payload spectrometers modules. ICU is in charge of two main tasks: the overall payload control (Instrument Control Function) and the housekeepings and scientific data digital processing (Data Processing Function), including the lossless compression prior to store the science data to the Solid State Mass Memory of the Spacecraft. These two main tasks are accomplished thanks to the Payload On Board Software (P-OBSW) running on the ICU CPUs.Comment: Experimental Astronomy - EChO Special Issue 201

    The Visible and Near Infrared module of EChO

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    The Visible and Near Infrared (VNIR) is one of the modules of EChO, the Exoplanets Characterization Observatory proposed to ESA for an M-class mission. EChO is aimed to observe planets while transiting by their suns. Then the instrument had to be designed to assure a high efficiency over the whole spectral range. In fact, it has to be able to observe stars with an apparent magnitude Mv= 9-12 and to see contrasts of the order of 10-4 - 10-5 necessary to reveal the characteristics of the atmospheres of the exoplanets under investigation. VNIR is a spectrometer in a cross-dispersed configuration, covering the 0.4-2.5 micron spectral range with a resolving power of about 330 and a field of view of 2 arcsec. It is functionally split into two channels respectively working in the 0.4-1 and 1.0-2.5 micron spectral ranges. Such a solution is imposed by the fact the light at short wavelengths has to be shared with the EChO Fine Guiding System (FGS) devoted to the pointing of the stars under observation. The spectrometer makes use of a HgCdTe detector of 512 by 512 pixels, 18 micron pitch and working at a temperature of 45K as the entire VNIR optical bench. The instrument has been interfaced to the telescope optics by two optical fibers, one per channel, to assure an easier coupling and an easier colocation of the instrument inside the EChO optical bench.Comment: 26 page

    Updates on the PeNCIL project

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    By comparing measured and expected polarization in the HI Lyα 121.6 nm coronal emission line it is possible to infer the magnetic ïŹeld in the solar corona. PeNCIL is the ideal device to perform such a measurement. It is a light transmitting polarimeter optimized at 121.6 nm, completely free of mechanical moving parts, thought as part of an internally occulted coronagraph to be ïŹ‚own aboard a future small solar mission. Its optical components are in de Senarmont conïŹguration: a ïŹxed MgF2 quarter wave retarder, a nano-wire grid polarizer (nano-WGP) and a MgF2 variable retarder modulated through a calibrated piezo-clamp (PCVR). The nano-WGP and the PCVR represent a ïŹrst-ever achievement in the history of technology development for VUV. The nano-WGP fabrication is at the edge of the current nanotechnology since the pitch between wires shall be 40 nm. The PCVR is based on a MgF 2 parallelepipedic sample refractive index variations as produced by a piezo-electric clamp. This work addresses the status of the project with particular emphasis on the design and manufacturing of the nano-WGP and the PCVR

    GROWTH INHIBITION AND DIFFERENTIATION OF HUMAN BREAST CANCER CELLS BY THE PAFR ANTAGONIST WEB-2086

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    WEB-2086 – an antagonist of platelet-activating factor receptor (PAFR) with known anti-inflammatory, antiangiogenic and antileukaemic properties – also proved to inhibit the proliferation in human solid tumour cell lines of different histology, and with much higher efficacy than in normal fibroblasts. A detailed analysis of WEB-2086 anticancer activity was then performed focusing on breast adenocarcinoma MCF-7 and MDA-MB-231 cells. WEB-2086-treated cells, either expressing (MCF-7) or unexpressing (MDA-MB-231) the oestrogen receptor (ER)α, underwent a dose-dependent growth arrest (IC(50)=0.65±0.09 and 0.41±0.07 mM, respectively) and accumulation in G(0)–G(1) phase. WEB-2086 also induced morphological and functional changes typical of mature mammary phenotype including (i) cell enlargement and massive neutral lipid deposition (best accomplished in MCF-7 cells); (ii) decrease in motility and active cathepsin D levels (mainly observed in highly invasive MDA-MB-231 cells). The expression of ERα was neither increased nor reactivated in treated MCF-7 or MDA-MB-231 cells, respectively. WEB-2086-induced differentiation in breast cancer cells involved the upregulation of PTEN, a key tumour suppressor protein opposing tumorigenesis, and was apparently independent of p53, PAFR, peripheral benzodiazepine receptor and ERα status. Overall, WEB-2086 can be proposed as an effective antiproliferative and differentiative agent with interesting translational opportunities to treat breast cancers in support to conventional chemotherapy

    The ARIEL Instrument Control Unit design for the M4 Mission Selection Review of the ESA's Cosmic Vision Program

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    The Atmospheric Remote-sensing Infrared Exoplanet Large-survey mission (ARIEL) is one of the three present candidates for the ESA M4 (the fourth medium mission) launch opportunity. The proposed Payload will perform a large unbiased spectroscopic survey from space concerning the nature of exoplanets atmospheres and their interiors to determine the key factors affecting the formation and evolution of planetary systems. ARIEL will observe a large number (>500) of warm and hot transiting gas giants, Neptunes and super-Earths around a wide range of host star types, targeting planets hotter than 600 K to take advantage of their well-mixed atmospheres. It will exploit primary and secondary transits spectroscopy in the 1.2-8 um spectral range and broad-band photometry in the optical and Near IR (NIR). The main instrument of the ARIEL Payload is the IR Spectrometer (AIRS) providing low-resolution spectroscopy in two IR channels: Channel 0 (CH0) for the 1.95-3.90 um band and Channel 1 (CH1) for the 3.90-7.80 um range. It is located at the intermediate focal plane of the telescope and common optical system and it hosts two IR sensors and two cold front-end electronics (CFEE) for detectors readout, a well defined process calibrated for the selected target brightness and driven by the Payload's Instrument Control Unit (ICU).Comment: Experimental Astronomy, Special Issue on ARIEL, (2017

    Comparing extrapolations of the coronal magnetic field structure at 2.5 solar radii with multi-viewpoint coronagraphic observations

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    The magnetic field shapes the structure of the solar corona but we still know little about the interrelationships between the coronal magnetic field configurations and the resulting quasi-stationary structures observed in coronagraphic images (as streamers, plumes, coronal holes). One way to obtain information on the large-scale structure of the coronal magnetic field is to extrapolate it from photospheric data and compare the results with coronagraphic images. Our aim is to verify if this comparison can be a fast method to check systematically the reliability of the many methods available to reconstruct the coronal magnetic field. Coronal fields are usually extrapolated from photospheric measurements typically in a region close to the central meridian on the solar disk and then compared with coronagraphic images at the limbs, acquired at least 7 days before or after to account for solar rotation, implicitly assuming that no significant changes occurred in the corona during that period. In this work, we combine images from three coronagraphs (SOHO/LASCO-C2 and the two STEREO/SECCHI-COR1) observing the Sun from different viewing angles to build Carrington maps covering the entire corona to reduce the effect of temporal evolution to ~ 5 days. We then compare the position of the observed streamers in these Carrington maps with that of the neutral lines obtained from four different magnetic field extrapolations, to evaluate the performances of the latter in the solar corona. Our results show that the location of coronal streamers can provide important indications to discriminate between different magnetic field extrapolations.Comment: Accepted by A&A the 20th of May, 201

    Impact of calreticulin mutations on clinical and hematological phenotype and outcome in essential thrombocythemia

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    Key Points CALR mutations occur in half of JAK2 and MPL wt patients with ET and associate with some distinctive phenotypic traits. Patients with ET harboring CALR mutations are at significantly lower risk of thrombosis compared with JAK2- and MPL-mutated patients
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