Gaia is a cornerstone mission in the science programme of the European Space 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.

This paper presents the specification, design, and development of the Radial Velocity Spectrometer (RVS) on the European Space Agency’s Gaia mission. Starting with the rationale for the full six dimensions of phase space in the dynamical modelling of the Galaxy, the scientific goals and derived top-level instrument requirements are discussed, leading to a brief description of the initial concepts for the instrument. The main part of the paper is a description of the flight RVS, considering the optical design, the focal plane, the detection and acquisition chain, and the as-built performance drivers and critical technical areas. After presenting the pre-launch performance predictions, the paper concludes with the post-launch developments and mitigation strategies, together with a summary of the in-flight performance at the end of commissioning.

A study of endoscopic carpal tunnel release was carried out in three parts, consisting of initial cadaveric dissections, a prospective pilot study of 20 patients and a prospective, randomized trial of 71 patients comparing endoscopic with open decompression. In the main trial, 25 patients with bilateral symptoms underwent simultaneous endoscopic and open release, with the remainder randomized to one or other technique. Both techniques effectively decompressed the median nerve. A significant improvement in group and pinch strength over 3 months was achieved in those undergoing endoscopic surgery. Average return to work was 14 days in the endoscopic series and 39 days in the open series. A complication rate of 35% was achieved with the transbursal endoscopic technique, 3.7% with the extrabursal endoscopic technique and 13.5% in the open series.

Background Tranexamic acid (TXA) can reduce intra- and postoperative bleeding as well as minimizing postoperative swelling and ecchymosis. It can be administered both intravenously and topically during surgery with minimal side effects. Objectives To assess the evidence of TXA use in aesthetic surgery and to complete a survey of current practice of full British Association of Aesthetic Plastic Surgeons (BAAPS) members. Methods The authors performed a literature review and online survey of full BAAPS members. Results There is an increased indication of TXA use in aesthetic surgery. It provides multiple surgeon and patient benefits. Conclusions TXA is a useful adjunct in aesthetic surgery.

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