27 research outputs found

    The Gaia-ESO Survey: Empirical determination of the precision of stellar radial velocities and projected rotation velocities

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    Context. The Gaia-ESO Survey (GES) is a large public spectroscopic survey at the European Southern Observatory Very Large Telescope. Aims. A key aim is to provide precise radial velocities (RVs) and projected equatorial velocities (v sin i) for representative samples of Galactic stars, which will complement information obtained by the Gaia astrometry satellite. Methods. We present an analysis to empirically quantify the size and distribution of uncertainties in RV and v sin i using spectra from repeated exposures of the same stars. Results. We show that the uncertainties vary as simple scaling functions of signal-to-noise ratio (S/N) and v sin i, that the uncertainties become larger with increasing photospheric temperature, but that the dependence on stellar gravity, metallicity and age is weak. The underlying uncertainty distributions have extended tails that are better represented by Student's t-distributions than by normal distributions. Conclusions. Parametrised results are provided, which enable estimates of the RV precision for almost all GES measurements, and estimates of the v sin i precision for stars in young clusters, as a function of S/N, v sin i and stellar temperature. The precision of individual high S/N GES RV measurements is 0.22-0.26 kms-1, dependent on instrumental configuration

    VizieR Online Data Catalog: Gamma Vel cluster membership and IMF (Prisinzano+, 2016)

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    We derived a list as complete as possible of confirmed members of the young open cluster Gamma Velorum, with the aim of deriving general cluster properties such as the IMF. We used all available spectroscopic membership indicators within the Gaia-ESO public archive, based on spectra acquired with FLAMES a the VLT using the GIRAFFE intermediate-resolution spectrograph. In addition, we used literature photometry and X-ray data. For each membership criterion, we derived the most complete list of candidate cluster members. Then, we considered photometry, gravity, and radial velocities as necessary conditions for selecting a subsample of candidates whose membership was confirmed by using the lithium and Halpha lines and X-rays as youth indicators. Table 5 lists the fundamental parameters of the confirmed and possible members in Gamma Velorum, i.e. photometry, radial velocities, equivalent widths of the lithium line, the Halpha activity index, the X-ray flag, the gravity gamma index and the stellar masses. Finally the binarity and membership flags are given. (1 data file)

    Gaia Early Data Release 3: Structure and properties of the Magellanic Clouds

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    We compare the Gaia DR2 and Gaia EDR3 performances in the study of the Magellanic Clouds and show the clear improvements in precision and accuracy in the new release. We also show that the systematics still present in the data make the determination of the 3D geometry of the LMC a difficult endeavour; this is at the very limit of the usefulness of the Gaia EDR3 astrometry, but it may become feasible with the use of additional external data. We derive radial and tangential velocity maps and global profiles for the LMC for the several subsamples we defined. To our knowledge, this is the first time that the two planar components of the ordered and random motions are derived for multiple stellar evolutionary phases in a galactic disc outside the Milky Way, showing the differences between younger and older phases. We also analyse the spatial structure and motions in the central region, the bar, and the disc, providing new insights into features and kinematics. Finally, we show that the Gaia EDR3 data allows clearly resolving the Magellanic Bridge, and we trace the density and velocity flow of the stars from the SMC towards the LMC not only globally, but also separately for young and evolved populations. This allows us to confirm an evolved population in the Bridge that is slightly shift from the younger population. Additionally, we were able to study the outskirts of both Magellanic Clouds, in which we detected some well-known features and indications of new ones

    The Gaia mission

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    Gaia is a cornerstone mission in the science programme of the EuropeanSpace Agency (ESA). The spacecraft construction was approved in 2006, following a study in which the original interferometric concept was changed to a direct-imaging approach. Both the spacecraft and the payload were built by European industry. The involvement of the scientific community focusses on data processing for which the international Gaia Data Processing and Analysis Consortium (DPAC) was selected in 2007. Gaia was launched on 19 December 2013 and arrived at its operating point, the second Lagrange point of the Sun-Earth-Moon system, a few weeks later. The commissioning of the spacecraft and payload was completed on 19 July 2014. The nominal five-year mission started with four weeks of special, ecliptic-pole scanning and subsequently transferred into full-sky scanning mode. We recall the scientific goals of Gaia and give a description of the as-built spacecraft that is currently (mid-2016) being operated to achieve these goals. We pay special attention to the payload module, the performance of which is closely related to the scientific performance of the mission. We provide a summary of the commissioning activities and findings, followed by a description of the routine operational mode. We summarise scientific performance estimates on the basis of in-orbit operations. Several intermediate Gaia data releases are planned and the data can be retrieved from the Gaia Archive, which is available through the Gaia home page. http://www.cosmos.esa.int/gai

    Urticaria and anaphilaxis in a child after inhalation of lentils vapours: a case report and literature review

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    <p>Abstract</p> <p>Background</p> <p>Among legumes, lentils seem to be the most common legume implicated in pediatric allergic reactions in the Mediterranean area and India, and usually they start early in life, below 4 years of age.</p> <p>Case report</p> <p>A 22 -month-old child was admitted to our Pediatric Department for anaphylaxis and urticaria. At the age of 9 months she presented a first episode of angioedema and laryngeal obstruction, due to a second assumption of lentils in her diet. At admission we performed routine analyses that were all in the normal range, except for the dosage of specific IgE, that revealed a positive result for lentils. Prick tests too were positive for lentils, while they were all negative for other main food allergens. The child also performed a prick by prick that gave the same positive result (with a wheal of 8 mm of diameter). The child had not previously eaten lentils and other legumes, but her pathological anamnesis highlighted that the allergic reaction appeared soon after the inhalation of cooking lentil vapours when the child entered the kitchen Therefore a diagnosis of lentils vapours allergy was made.</p> <p>Conclusions</p> <p>Our case shows the peculiarity of a very early onset. In literature there are no data on episodes of anaphylaxis in so young children, considering that our child was already on lentils exclusion diet. Therefore a diet of exclusion does not absolutely preserve patients from allergic reactions, that can develop also after their cooking steams inhalation.</p

    Supplementary suckling technique with expressed breast milk can increase the belief in breastfeeding

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    In Tanzania in 2015 more than 100,000 Severe Acute Malnourished (SAM) cases were estimated, with high risk of dying. SAM infants under‐6 months (U‐6 mo) need special care and should always be treated as inpatient. If it is possible to restore Exclusive Breast Feeding (EBF), therapeutic feeds can be best delivered by the Supplementary Suckling Technique (SST). A male infant, born at term with a body weight (BW) of 3100 g, was admitted in hospital at 6 weeks of age with a BW of 1550 g. The child was diagnosed as marasmatic SAM. He was started on therapeutic milk administered by SST. Mother was instructed in proper SST use and counseled in order to re‐establish effective EBF. As weight gain was maintained, SST was stopped and the child was put on EBF, but BW started to decrease again. SST was then applied using Expressed Breast Milk (EBM), gradually stepped down and stopped. Since BW started to decrease again it emerged that the mother decided by herself to start again to administer EBM by SST but in insuficient quantity. She was invited to breastfeed frequently under supervision, creating a better awareness of breastfeeding practices. Since the child showed correct weight gain on EBF he was discharged, with a BW of 2420 g. According to our experience SST with EBM could be useful in developing countries to increase awareness and belief on successful breast feeding

    Hepatitis B vaccine by intradermal route in non responder patients: An update

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    none8noFilippelli, Martina; Lionetti, Elena; Gennaro, Alessia; Lanzafame, Angela; Arrigo, Teresa; Salpietro, Carmelo; La Rosa, Mario; Leonardi, SalvatoreFilippelli, Martina; Lionetti, MARIA ELENA; Gennaro, Alessia; Lanzafame, Angela; Arrigo, Teresa; Salpietro, Carmelo; La Rosa, Mario; Leonardi, Salvator
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