22 research outputs found

    Pharyngocutaneous fistula following total laryngectomy: analysis of risk factors, prognosis and treatment modalities.

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    The aim of this study was to establish the incidence, risk factors, and the management of pharyngocutaneous fistula (PCF) after primary and salvage total laryngectomy. A retrospective, match-paired analysis of 86 patients who developed fistula after total laryngectomy was carried out and compared with a control group of 86 patients without fistula, randomly selected from a pool of 352 total laryngectomies, performed between January 1999 to October 2014. The overall incidence of PCF in the series was 24.4%; we recorded rates of 19.0%, 28.6% and 30.3% following primary total laryngectomy (PTL), salvage laryngectomy post-radiotherapy (RT-STL) and salvage laryngectomy postchemoradiotherapy (CRT-STL), respectively. Multivariate analysis revealed that the relative risk of fistula was respectively 2.47, 3.09 and 7.69 for hypoalbuminaemia ≤3.5 g/dL, RT-STL and CRT-STL. An early onset of PCF within 10 postoperative days was recorded in case of salvage total laryngectomy. The management of PCF significantly differed between PTL, RT-STL and CTRT-STL, with exclusive conservative treatment for PTL (93.55%), while in the CRT-STL group surgical closure with regional flaps (58.82%) prevailed. Conservative management, adjuvant hyperbaric oxygen therapy and surgical closure were equally distributed in the RT-STL group. Thorough knowledge of patient-related risk factors and its prognostic value, allows the surgeon to better evaluate preventive strategies with the aim of minimising fistula formation, hospitalisation times and related costs

    Simplified Models for Dark Matter and Missing Energy Searches at the LHC

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    The study of collision events with missing energy as searches for the dark matter (DM) component of the Universe are an essential part of the extensive program looking for new physics at the LHC. Given the unknown nature of DM, the interpretation of such searches should be made broad and inclusive. This report reviews the usage of simplified models in the interpretation of missing energy searches. We begin with a brief discussion of the utility and limitation of the effective field theory approach to this problem. The bulk of the report is then devoted to several different simplified models and their signatures, including s-channel and t-channel processes. A common feature of simplified models for DM is the presence of additional particles that mediate the interactions between the Standard Model and the particle that makes up DM. We consider these in detail and emphasize the importance of their inclusion as final states in any coherent interpretation. We also review some of the experimental progress in the field, new signatures, and other aspects of the searches themselves. We conclude with comments and recommendations regarding the use of simplified models in Run-II of the LHC.Comment: v2. references added, version submitted to journal. v1. 47 pages, 13 plot

    LO WFS of MAORY: performance and sky coverage assessment

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    MAORY is the Multi-Conjugate Adaptive Optics module for the European ELT. It will provide a wide-field correction for the first-light instrument MICADO. The Low-Order wavefront modes will be sensed on 3 Natural Guide Stars with Shack-Hartmann Wavefront Sensors, so-called the LO WFS. In the presented work, we focus on the numerical study of the main aspects that depend on the LO WFS design and operational use: low-order sensing performance and sky coverage

    MAORY real-time computer preliminary design

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    MAORY is the Multi-conjugate Adaptive Optics module for the Extremely Large Telescope and it will be located on the Nasmyth platform of the telescope to feed scientific instruments. MAORY will re-image the telescope focal plane providing multi-conjugate adaptive optics correction of the wavefront distortion induced by the atmosphere. The system is based on six laser guide stars and three natural guide stars for sensing the wavefront distortion and three deformable mirrors for correcting it. We will show the current status of the preliminary design of the Real Time Computer in charge of carrying out all the calculations based on the measurements of the guide stars wavefront sensors. The hard real time (primary) loops are in charge of controlling the deformable mirrors and the lasers jitter compensation while the soft real- time (secondary) loops are in charge of updating the primary loops parameters as well as measuring or estimating the atmospheric parameters and the system performance. Telemetry data management/recording and calibration are the other tasks carried out by the real time computer

    Status of the preliminary design of the NGS WFS subsystem of MAORY

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    The Natural Guide Star (NGS) Wavefront Sensor (WFS) sub-system of MAORY implements 3 Low-Order and Reference (LOR) WFS needed by the Multi-Conjugate Adaptive Optics (MCAO) system. Each LOR WFS has 2 main purposes: first, to sense the fast low-order modes that are affected by atmospheric anisoplanatism and second, to de-trend the LGS measurements from the slow spatial and temporal drifts of the Sodium layer. These features require to implement 2 different WFS sharing the same NGS and optical breadboard but being respectively a 2Ă—2 Shack-Hartman Sensor (SHS) working at infrared wavelengths and a slow 10Ă—10 SHS at visible bands. The NG WFS sub-system also provides a common support plate for the 3 WFS and their control electronics and cabling. The paper summarizes the status of the preliminary design of the LOR Module on the road to the MAORY Preliminary Design Review (PDR), focusing mainly on the description and analysis of the opto-mechanical arrangement foreseen for the NGS WFS sub-system. Performances and the design trade-offs of the NGS WFS sub-system are analyzed in a complementary paper. First, the requirement imposed by MAORY AO system are discussed. Then the paper gives an overview of the opto-mechanical arrangement for the main components of the sub-system: the support plate, the 3 WFS units and their interfaces to the instrument rotator. In the end the paper discusses the sub-system pointing and WFE budgets derived from different analyses. The design concept for the electronic devices of the sub-system, the cabinet arrangement and the cabling sheme are given in second complementary paper

    Numerical simulations of MAORY MCAO module for the ELT

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    MAO (MAORY Adaptive Optics) is the a developed numerical simulation tool for adaptive optics. It was created especially to simulate the performance of the MAORY MCAO module of the Extremely Large Telescope. It is a full end-to-end Monte-Carlo code able to perform different flavors of adaptive optics simulation. We used it to investigate the performance of a the MAORY and some specific issue related to calibration, acquisition and operation strategies. As, MAORY, MAO will implement Multi-conjugate Adaptive Optics combining Laser Guide Stars (LGS) and Natural Guide Stars (NGS) measurements. The implementation of the reference truth WFS completes the scheme. The simulation tool implements the various aspect of the MAORY in an end to end fashion. The code has been developed using IDL and use libraries in C++ and CUDA for efficiency improvements. Here we recall the code architecture, we describe the modeled instrument components and the control strategies implemented in the code

    The MAORY laser guide star wavefront sensor: design status

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    MAORY will be the multi-adaptive optics module feeding the high resolution camera and spectrograph MICADO at the Extremely Large Telescope (ELT) first light. In order to ensure high and homogeneous image quality over the MICADO field of view and high sky coverage, the baseline is to operate wavefront sensing using six Sodium Laser Guide Stars. The Laser Guide Star Wavefront Sensor (LGS WFS) is the MAORY sub-system devoted to real-time measurement of the high order wavefront distortions. In this paper we describe the MAORY LGS WFS current design, including opto-mechanics, trade-offs and possible future improvements

    A preliminary overview of the multiconjugate adaptive optics module for the E-ELT

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    ABSTRACT The multi-conjugate adaptive optics module for the European Extremely Large Telescope has to provide a corrected field of medium to large size (up to 2 arcmin), over the baseline wavelength range 0.8-2.4 µm. The current design is characterized by two post-focal deformable mirrors, that complement the correction provided by the adaptive telescope; the wavefront sensing is performed by means of a high-order multiple laser guide star wavefront sensor and by a loworder natural guide star wavefront sensor. The present status of a two years study for the advanced conceptual design of this module is reported
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