4,282 research outputs found

    Endoscopic Skull Base Surgery

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    Endoscopic skull base surgery has undergone rapid advancement in the past decade moving from pituitary surgery to suprasellar lesions and now to a myriad of lesions extending from the cribriform plate to C2 and laterally out to the infratemporal fossa and petrous apex. Evolution of several technological advances as well as advances in understanding of endoscopic anatomy and the development of surgical techniques both in resection and reconstruction have fostered this capability. Management of benign disease via endoscopic methods is largely accepted now but more data is needed before the controversy on the role of endoscopic management of malignant disease is decided. Continued advances in surgical technique, navigation systems, endoscopic imaging technology, and robotics assure continued brisk evolution in this expanding field

    AVIRIS ground data-processing system

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    The Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) has been under development at JPL for the past four years. During this time, a dedicated ground data-processing system has been designed and implemented to store and process the large amounts of data expected. This paper reviews the objectives of this ground data-processing system and describes the hardware. An outline of the data flow through the system is given, and the software and incorporated algorithms developed specifically for the systematic processing of AVIRIS data are described

    The JCMT Transient Survey: An Extraordinary Submillimetre Flare in the T Tauri Binary System JW 566

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    The binary T Tauri system JW 566 in the Orion Molecular Cloud underwent an energetic, short-lived flare observed at submillimetre wavelengths by the SCUBA-2 instrument on 26 November 2016 (UT). The emission faded by nearly 50% during the 31 minute integration. The simultaneous source fluxes averaged over the observation are 500 +/- 107 mJy/beam at 450 microns and 466 +/- 47 mJy/beam at 850 microns. The 850 micron flux corresponds to a radio luminosity of Lν=8×1019L_{\nu}=8\times10^{19} erg/s/Hz, approximately one order of magnitude brighter (in terms of νLν\nu L_{\nu}) than that of a flare of the young star GMR-A, detected in Orion in 2003 at 3mm. The event may be the most luminous known flare associated with a young stellar object and is also the first coronal flare discovered at sub-mm wavelengths. The spectral index between 450 microns and 850 microns of α=0.11\alpha = 0.11 is broadly consistent with non-thermal emission. The brightness temperature was in excess of 6×1046\times10^{4} K. We interpret this event to be a magnetic reconnection that energised charged particles to emit gyrosynchrotron/synchrotron radiation.Comment: Accepted in ApJ. 16 pages (single column), 6 figure

    The JCMT Transient Survey: An Extraordinary Submillimeter Flare in the T Tauri Binary System JW 566

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    © 2019 The American Astronomical Society. All rights reserved.The binary T Tauri system JW 566 in the Orion Molecular Cloud underwent an energetic, short-lived flare observed at submillimetre wavelengths by the SCUBA-2 instrument on 26 November 2016 (UT). The emission faded by nearly 50% during the 31 minute integration. The simultaneous source fluxes averaged over the observation are 500 +/- 107 mJy/beam at 450 microns and 466 +/- 47 mJy/beam at 850 microns. The 850 micron flux corresponds to a radio luminosity of Lν=8×1019L_{\nu}=8\times10^{19} erg/s/Hz, approximately one order of magnitude brighter (in terms of νLν\nu L_{\nu}) than that of a flare of the young star GMR-A, detected in Orion in 2003 at 3mm. The event may be the most luminous known flare associated with a young stellar object and is also the first coronal flare discovered at sub-mm wavelengths. The spectral index between 450 microns and 850 microns of α=0.11\alpha = 0.11 is broadly consistent with non-thermal emission. The brightness temperature was in excess of 6×1046\times10^{4} K. We interpret this event to be a magnetic reconnection that energised charged particles to emit gyrosynchrotron/synchrotron radiation.Peer reviewedFinal Published versio

    No bursts detected from FRB121102 in two 5-hour observing campaigns with the Robert C. Byrd Green Bank Telescope

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    Here, we report non-detection of radio bursts from Fast Radio Burst FRB 121102 during two 5-hour observation sessions on the Robert C. Byrd 100-m Green Bank Telescope in West Virginia, USA, on December 11, 2017, and January 12, 2018. In addition, we report non-detection during an abutting 10-hour observation with the Kunming 40-m telescope in China, which commenced UTC 10:00 January 12, 2018. These are among the longest published contiguous observations of FRB 121102, and support the notion that FRB 121102 bursts are episodic. These observations were part of a simultaneous optical and radio monitoring campaign with the the Caltech HIgh- speed Multi-color CamERA (CHIMERA) instrument on the Hale 5.1-m telescope.Comment: 1 table, Submitted to RN of AA
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