Publications of ???     Results 1-20 of 713. 1 2 3 4 5 6 7 8 9 10   The path towards high-contrast imaging with the VLTI: the Hi-5 projectDefrere, Denis ; Absil, Olivier ; Berger, J.-P. et alin Experimental Astronomy: Astrophysical Instrumentation and Methods (in press), 1801The development of high-contrast capabilities has long been recognized as one of the top priorities for the VLTI. As of today, the VLTI routinely achieves contrasts of a few 10$^{-3}$ in the near-infrared ... [more ▼]The development of high-contrast capabilities has long been recognized as one of the top priorities for the VLTI. As of today, the VLTI routinely achieves contrasts of a few 10$^{-3}$ in the near-infrared with PIONIER (H band) and GRAVITY (K band). Nulling interferometers in the northern hemisphere and non-redundant aperture masking experiments have, however, demonstrated that contrasts of at least a few 10$^{-4}$ are within reach using specific beam combination and data acquisition techniques. In this paper, we explore the possibility to reach similar or higher contrasts on the VLTI. After reviewing the state-of-the-art in high-contrast infrared interferometry, we discuss key features that made the success of other high-contrast interferometric instruments (e.g., integrated optics, nulling, closure phase, and statistical data reduction) and address possible avenues to improve the contrast of the VLTI by at least one order of magnitude. In particular, we discuss the possibility to use integrated optics, proven in the near-infrared, in the thermal near-infrared (L and M bands, 3-5 $\mu$m), a sweet spot to image and characterize young extra-solar planetary systems. Finally, we address the science cases of a high-contrast VLTI imaging instrument and focus particularly on exoplanet science (young exoplanets, planet formation, and exozodiacal disks), stellar physics (fundamental parameters and multiplicity), and extragalactic astrophysics (active galactic nuclei and fundamental constants). Synergies and scientific preparation for other potential future instruments such as the Planet Formation Imager are also briefly discussed. [less ▲]Detailed reference viewed: 8 (0 ULiège) Human brain patterns underlying vigilant attention: impact of sleep debt, circadian phase and attentional engagementMaire, Micheline; Reichert, Carolin Franziska; Gabel, Virginie et alin Scientific Reports (2018), 8(1), 970Detailed reference viewed: 19 (1 ULiège) The Ionospheric Connection Explorer Mission: Mission Goals and DesignImmel, T. J.; England, S. L.; Mende, S. B. et alin Space Science Reviews (2018), 214(13), The Ionospheric Connection Explorer, or ICON, is a new NASA Explorer mission that will explore the boundary between Earth and space to understand the physical connection between our world and our space ... [more ▼]The Ionospheric Connection Explorer, or ICON, is a new NASA Explorer mission that will explore the boundary between Earth and space to understand the physical connection between our world and our space environment. This connection is made in the ionosphere, which has long been known to exhibit variability associated with the sun and solar wind. However, it has been recognized in the 21st century that equally significant changes in ionospheric conditions are apparently associated with energy and momentum propagating upward from our own atmosphere. ICON's goal is to weigh the competing impacts of these two drivers as they influence our space environment. Here we describe the specific science objectives that address this goal, as well as the means by which they will be achieved. The instruments selected, the overall performance requirements of the science payload and the operational requirements are also described. ICON's development began in 2013 and the mission is on track for launch in 2018. ICON is developed and managed by the Space Sciences Laboratory at the University of California, Berkeley, with key contributions from several partner institutions. [less ▲]Detailed reference viewed: 17 (2 ULiège) Effect of procalcitonin-guided antibiotic treatment on mortality in acute respiratory infections: a patient level meta-analysisSchuetz, Philipp; Wirz, Yannick; Sager, Ramon et alin Lancet Infectious Diseases (2018), 18(1), 95-107Background In February, 2017, the US Food and Drug Administration approved the blood infection marker procalcitonin for guiding antibiotic therapy in patients with acute respiratory infections. This meta ... [more ▼]Background In February, 2017, the US Food and Drug Administration approved the blood infection marker procalcitonin for guiding antibiotic therapy in patients with acute respiratory infections. This meta-analysis of patient data from 26 randomised controlled trials was designed to assess safety of procalcitonin-guided treatment in patients with acute respiratory infections from different clinical settings. Methods Based on a prespecified Cochrane protocol, we did a systematic literature search on the Cochrane Central Register of Controlled Trials, MEDLINE, and Embase, and pooled individual patient data from trials in which patients with respiratory infections were randomly assigned to receive antibiotics based on procalcitonin concentrations (procalcitonin-guided group) or control. The coprimary endpoints were 30-day mortality and setting-specific treatment failure. Secondary endpoints were antibiotic use, length of stay, and antibiotic side-effects. Findings We identified 990 records from the literature search, of which 71 articles were assessed for eligibility after exclusion of 919 records. We collected data on 6708 patients from 26 eligible trials in 12 countries. Mortality at 30 days was significantly lower in procalcitonin-guided patients than in control patients (286 [9%] deaths in 3336 procalcitonin-guided patients vs 336 [10%] in 3372 controls; adjusted odds ratio [OR] 0·83 [95% CI 0·70 to 0·99], p=0·037). This mortality benefit was similar across subgroups by setting and type of infection (pinteractions>0·05), although mortality was very low in primary care and in patients with acute bronchitis. Procalcitonin guidance was also associated with a 2·4-day reduction in antibiotic exposure (5·7 vs 8·1 days [95% CI −2·71 to −2·15], p<0·0001) and a reduction in antibiotic-related side-effects (16% vs 22%, adjusted OR 0·68 [95% CI 0·57 to 0·82], p<0·0001). Interpretation Use of procalcitonin to guide antibiotic treatment in patients with acute respiratory infections reduces antibiotic exposure and side-effects, and improves survival. Widespread implementation of procalcitonin protocols in patients with acute respiratory infections thus has the potential to improve antibiotic management with positive effects on clinical outcomes and on the current threat of increasing antibiotic multiresistance. Funding National Institute for Health Research. © 2018 Elsevier Ltd [less ▲]Detailed reference viewed: 28 (0 ULiège) A randomized phase II study evaluating different maintenance schedules of nab-Paclitaxel in the first-line treatment of metastatic breast cancer: final results of the IBCSG 42-12/BIG 2-12 SNAP trial.Gennari, A.; Sun, Z.; Hasler-Strub, U. et alin Annals of oncology : official journal of the European Society for Medical Oncology (2017)Background: The phase II SNAP trial was designed to evaluate the efficacy of alternative chemotherapy schedules for prolonged administration in HER2-negative metastatic breast cancer (MBC), after a short ... [more ▼]Background: The phase II SNAP trial was designed to evaluate the efficacy of alternative chemotherapy schedules for prolonged administration in HER2-negative metastatic breast cancer (MBC), after a short induction at conventional doses. Methods: Between April 2013 and August 2015, 258 women untreated with chemotherapy for MBC were randomly assigned to receive three different maintenance chemotherapy schedules after three cycles of identical induction chemotherapy: Arm A, nab-Paclitaxel 150 mg/m2 days 1,15 Q28; Arm B, nab-Paclitaxel 100 mg/m2 days 1,8,15 Q28; Arm C, nab-Paclitaxel 75 mg/m2 days 1,8,15,22 Q28. Induction was three cycles nab-Paclitaxel 150/125 mg/m2, days 1,8,15 Q28. The primary objective was to evaluate the efficacy of each maintenance schedule, in terms of progression-free survival (PFS), as compared to the historical reference of 7-month median PFS reported by previous studies with first-line docetaxel. One-sample, one-sided log-rank tests were utilized. Quality-of-life evaluation was performed, global indicator for physical well-being was defined as the primary endpoint; completion rates of quality-of-life forms were >90%. Results: 255 patients were evaluable for the primary endpoint. After 18.2 months median follow-up, 182 PFS events were observed. Median PFS was 7.9 months (90%CI 6.8-8.4) in Arm A, 9.0 months (90%CI 8.1-10.9) in Arm B and 8.5 months (90%CI 6.7-9.5) in Arm C. PFS in Arm B was significantly longer than the historical reference of first-line docetaxel (P=0.03). Grade>/=2 sensory neuropathy was reported in 37.9%, 36.1% and 31.2% of patients in Arm A, Arm B and Arm C, respectively (Grade>/=3 in 9.1%, 5.6% and 6.6% of patients, respectively). Noteworthy, the quality-of-life scores for sensory neuropathy did not worsen with prolonged nab-Paclitaxel administration in any of the maintenance arms. Conclusion: The SNAP trial demonstrated that alternative nab-Paclitaxel maintenance schedules with reduced dosages after a short induction at conventional doses are feasible and active in the first-line treatment of MBC. Registration: ClinicalTrials.gov NCT01746225. [less ▲]Detailed reference viewed: 23 (0 ULiège) NEAR: Low-mass Planets in α Cen with VISIRKasper, M.; Arsenault, R.; Käufl, H.-U. et alin The Messenger (2017), 169ESO, in collaboration with the Breakthrough Initiatives, is working to modify the Very Large Telescope mid-IR imager (VISIR) to greatly enhance its ability to search for potentially habitable planets ... [more ▼]ESO, in collaboration with the Breakthrough Initiatives, is working to modify the Very Large Telescope mid-IR imager (VISIR) to greatly enhance its ability to search for potentially habitable planets around both components of the binary Alpha Centauri, part of the closest stellar system to the Earth. Much of the funding for the NEAR (New Earths in the Alpha Cen Region) project is provided by the Breakthrough Initiatives, and ESO mostly provides staff and observing time. The concept combines adaptive optics using the deformable secondary mirror at Unit Telescope 4, a new annular groove phase mask (AGPM) coronagraph optimised for the most sensitive spectral bandpass in the N-band, and a novel internal chopper system for noise filtering based on a concept for longer wavelengths invented by the microwave pioneer Robert Dicke. The NEAR experiment is relevant to the mid-infrared METIS instrument on the Extremely Large Telescope, as the knowledge gained and proof of concept will be transferable. [less ▲]Detailed reference viewed: 8 (0 ULiège) Cognitive brain responses during circadian wake-promotion: evidence for sleep- pressure-dependent hypothalamic activationsReichert, Carolin Franziska; Maire, Micheline; Gabel, Virginie et alin Scientific Reports (2017), 7(1), Detailed reference viewed: 25 (0 ULiège) Gaia Data Release 1. Open cluster astrometry: performance, limitations, and future prospectsGaia Collaboration; van Leeuwen, F.; Vallenari, A. et alin Astronomy and Astrophysics (2017), 601Context. The first Gaia Data Release contains the Tycho-Gaia Astrometric Solution (TGAS). This is a subset of about 2 million stars for which, besides the position and photometry, the proper motion and ... [more ▼]Context. The first Gaia Data Release contains the Tycho-Gaia Astrometric Solution (TGAS). This is a subset of about 2 million stars for which, besides the position and photometry, the proper motion and parallax are calculated using Hipparcos and Tycho-2 positions in 1991.25 as prior information.