539 research outputs found

    Beam-Normal Single Spin Asymmetry in Elastic Electron Scattering off 28^{28}Si and 90^{90}Zr

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    We report on a new measurement of the beam-normal single spin asymmetry AnA_{\mathrm{n}} in the elastic scattering of 570 MeV transversely polarized electrons off 28^{28}Si and 90^{90}Zr at Q2=0.04GeV2/c2Q^{2}=0.04\, \mathrm{GeV}^2/c^2. The studied kinematics allow for a comprehensive comparison with former results on 12^{12}C. No significant mass dependence of the beam-normal single spin asymmetry is observed in the mass regime from 12^{12}C to 90^{90}Zr.Comment: Submitted for publication to Physics Letters

    SROS2: Usable Cyber Security Tools for ROS 2

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    ROS 2 is rapidly becoming a standard in the robotics industry. Built upon DDS as its default communication middleware and used in safety-critical scenarios, adding security to robots and ROS computational graphs is increasingly becoming a concern. The present work introduces SROS2, a series of developer tools and libraries that facilitate adding security to ROS 2 graphs. Focusing on a usability-centric approach in SROS2, we present a methodology for securing graphs systematically while following the DevSecOps model. We also demonstrate the use of our security tools by presenting an application case study that considers securing a graph using the popular Navigation2 and SLAM Toolbox stacks applied in a TurtleBot3 robot. We analyse the current capabilities of SROS2 and discuss the shortcomings, which provides insights for future contributions and extensions. Ultimately, we present SROS2 as usable security tools for ROS 2 and argue that without usability, security in robotics will be greatly impaired

    Performance of the CMS Cathode Strip Chambers with Cosmic Rays

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    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

    US Cosmic Visions: New Ideas in Dark Matter 2017: Community Report

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    This white paper summarizes the workshop "U.S. Cosmic Visions: New Ideas in Dark Matter" held at University of Maryland on March 23-25, 2017.Comment: 102 pages + reference

    Performance and Operation of the CMS Electromagnetic Calorimeter

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    The operation and general performance of the CMS electromagnetic calorimeter using cosmic-ray muons are described. These muons were recorded after the closure of the CMS detector in late 2008. The calorimeter is made of lead tungstate crystals and the overall status of the 75848 channels corresponding to the barrel and endcap detectors is reported. The stability of crucial operational parameters, such as high voltage, temperature and electronic noise, is summarised and the performance of the light monitoring system is presented

    Staphylococcus aureus forms spreading dendrites that have characteristics of active motility

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    Staphylococcus aureus is historically regarded as a non-motile organism. More recently it has been shown that S. aureus can passively move across agar surfaces in a process called spreading. We re-analysed spreading motility using a modified assay and fo- cused on observing the formation of dendrites: branching structures that emerge from the central colony. We discovered that S. aureus can spread across the surface of media in struc- tures that we term ‘comets’, which advance outwards and precede the formation of dendrites. We observed comets in a diverse selection of S. aureus isolates and they exhibit the following behaviours: (1) They consist of phenotypically distinct cores of cells that move forward and seed other S. aureus cells behind them forming a comet ‘tail’; (2) they move when other cells in the comet tail have stopped moving; (3) the comet core is held together by a matrix of slime; and (4) the comets etch trails in the agar as they move forwards. Comets are not con- sistent with spreading motility or other forms of passive motility. Comet behaviour does share many similarities with a form of active motility known as gliding. Our observations therefore suggest that S. aureus is actively motile under certain conditions

    Defining motility in the Staphylococci

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    The ability of bacteria to move is critical for their survival in diverse environments and multiple ways have evolved to achieve this. Two forms of motility have recently been described for Staphylococcus aureus, an organism previously considered to be non-motile. One form is called spreading, which is a type of sliding motility and the second form involves comet formation, which has many observable characteristics associated with gliding motility. Darting motility has also been observed in Staphylococcus epidermidis. This review describes how motility is defined and how we distinguish between passive and active motility. We discuss the characteristics of the various forms of Staphylococci motility, the molecular mechanisms involved and the potential future research directions

    Surgical approaches to the management of the intrathoracic goiter – A systematic review

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    Objective. Intrathoracic goiters (ITGs) pose numerous challenges to head and neck surgeons due to the intricate relationships with major vessels and other mediastinal structures. Surgical excision remains the mainstay of treatment and we herein present an update on this topic. Methods. A systematic review from 2017 to date was performed in the PubMed database and a total of 93 articles were identified and discussed, along with methodological issues and future directions in the research on ITGs. Results. Transcervical excision is the commonest approach for treating ITGs, yet the potential need for a transthoracic approach must be always kept in mind. An acceptable rate of postoperative complications is expected if surgeries are carried out by experienced and dedicated surgical teams. Conclusions. Surgical excision remains the principal treatment for ITGs and new less invasive techniques are being developed. Surgery for ITGs should be always carried out in specialist centres with experienced multidisciplinary teams

    Non-Surgical Approaches to the Management of the Intrathoracic Goiter—A Systematic Review

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    Background: Intrathoracic goiters (ITGs) are usually managed by surgical excision, However, over recent years, non-surgical strategies are emerging as an alternatives for treating this condition. Methods: A systematic review of research published since 2017 in the PubMed database was conducted and a total of 39 articles were retrieved, along with methodological issues and future directions in the research on ITGs. Results: Several non-surgical treatments exist, including radio-iodine ablation (RIA) and mini-invasive approaches, such as transcervical microwave ablation (TcMA), transcervical radiofrequency ablation (TcRfA), or selective embolization of the thyroid arteries (SETA). Despite encouraging reports, their current use remains limited. Conclusions: Treatment of ITGs requires a multidisciplinary thyroid team, and when non-surgical options are chosen, patients need to be carefully selected, and their outcomes must be prudently considered and discussed with the patient

    US Cosmic Visions: New Ideas in Dark Matter 2017: Community Report

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    This white paper summarizes the workshop "U.S. Cosmic Visions: New Ideas in Dark Matter" held at University of Maryland on March 23-25, 2017
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