Development of CCDs for REXIS on OSIRIS-REx

The Regolith x-ray Imaging Spectrometer (REXIS) is a coded-aperture soft x-ray imaging instrument on the OSIRIS-REx spacecraft to be launched in 2016. The spacecraft will fly to and orbit the near-Earth asteroid Bennu, while REXIS maps the elemental distribution on the asteroid using x-ray fluorescence. The detector consists of a 2×2 array of backilluminated 1k×1k frame transfer CCDs with a flight heritage to Suzaku and Chandra. The back surface has a thin p[superscript +]-doped layer deposited by molecular-beam epitaxy (MBE) for maximum quantum efficiency and energy resolution at low x-ray energies. The CCDs also feature an integrated optical-blocking filter (OBF) to suppress visible and near-infrared light. The OBF is an aluminum film deposited directly on the CCD back surface and is mechanically more robust and less absorptive of x-rays than the conventional free-standing aluminum-coated polymer films. The CCDs have charge transfer inefficiencies of less than 10[superscript -6], and dark current of 1e-/pixel/second at the REXIS operating temperature of –60 °C. The resulting spectral resolution is 115 eV at 2 KeV. The extinction ratio of the filter is ~10[superscript 12] at 625 nm.United States. National Aeronautics and Space Administration. Strategic Astrophysics Technology Program (Grant NNX12AF22G)United States. National Aeronautics and Space Administration (Contract NNG12FD70C)United States. National Aeronautics and Space Administration (IPR NNG12FC01I)United States. National Aeronautics and Space Administration. Strategic Astrophysics Technology Program (IPR NNH12AU04I)United States. Air Force (Contract FA8721-05-C-0002

New CTI Correction Method for the Spaced-Row Charge Injection of the Suzaku X-Ray Imaging Spectrometer

The charge transfer inefficiency (CTI) of the X-ray CCDs on board the Suzaku satellite (X-ray Imaging Spectrometers; XIS) has increased since the launch due to radiation damage, and the energy resolution has been degraded. To improve the CTI, we have applied a spaced-row charge injection (SCI) technique to the XIS in orbit; by injecting charges into CCD rows periodically, the CTI is actively decreased. The CTI in the SCI mode depends on the distance between a signal charge and a preceding injected row, and the pulse height shows periodic positional variations. Using in-flight data of onboard calibration sources and of the strong iron line from the Perseus cluster of galaxies, we studied the variation in detail. We developed a new method to correct the variation. By applying the new method, the energy resolution (FWHM) at 5.9 keV at March 2008 is ~155 eV for the front-illuminated CCDs and ~175 eV for the back-illuminated CCD.Comment: 7 pages, 14 figure

Quantum efficiency measurement of the Transiting Exoplanet Survey Satellite (TESS) CCD detectors

Very precise on-ground characterization and calibration of TESS CCD detectors will significantly assist in the analysis of the science data from the mission. An accurate optical test bench with very high photometric stability has been developed to perform precise measurements of the absolute quantum efficiency. The setup consists of a vacuum dewar with a single MIT Lincoln Lab CCID-80 device mounted on a cold plate with the calibrated reference photodiode mounted next to the CCD. A very stable laser-driven light source is integrated with a closed-loop intensity stabilization unit to control variations of the light source down to a few parts-per-million when averaged over 60 s. Light from the stabilization unit enters a 20 inch integrating sphere. The output light from the sphere produces near-uniform illumination on the cold CCD and on the calibrated reference photodiode inside the dewar. The ratio of the CCD and photodiode signals provides the absolute quantum efficiency measurement. The design, key features, error analysis, and results from the test campaign are presented.United States. National Aeronautics and Space Administration (contract number NNG14FC03C

Testing and characterization of the TESS CCDs

The Transiting Exoplanet Survey Satellite (TESS) is an Explorer-class mission dedicated to finding planets around bright, nearby stars so that more detailed follow-up studies can be done. TESS is due to launch in 2017 and careful characterization of the detectors will need to be completed on ground before then to ensure that the cameras will be within their photometric requirement of 60ppm/hr. TESS will fly MITLincoln Laboratories CCID-80s as the main scientific detector for its four cameras. They are 100μm deep depletion devices which have low dark current noise levels and can operate at low light levels at room temperature. They also each have a frame store region, which reduces smearing during readout and allows for near continuous integration. This paper describes the hardware and methodology that were developed for testing and characterizing individual CCID-80s. A dark system with no stimuli was used to measure the dark current. Fe 55 and Cd 109 X-ray sources were used to establish gain at low signal levels and its temperature dependence. An LED system that generates a programmable series of pulses was used in conjunction with an integrating sphere to measure pixel response non-uniformity (PRNU) and gain at higher signal levels. The same LED system was used with a pinhole system to evaluate the linearity and charge conservation capability of the CCID-80s.United States. National Aeronautics and Space Administration (contract number NNG14FC03C

Randomized, placebo-controlled trials of dichlorphenamide in periodic paralysis

Objective: To determine the short-term and long-term effects of dichlorphenamide (DCP) on attack frequency and quality of life in hyperkalemic (HYP) and hypokalemic (HOP) periodic paralysis. Methods: Two multicenter randomized, double-blind, placebo-controlled trials lasted 9 weeks (Class I evidence), followed by a 1-year extension phase in which all participants received DCP. Forty-four HOP and 21 HYP participants participated. The primary outcome variable was the average number of attacks per week over the final 8 weeks of the double-blind phase. Results: The median attack rate was lower in HOP participants on DCP than in participants on placebo (0.3 vs 2.4, p 0.02). The 9-week mean change in the Physical Component Summary score of the Short Form-36 was also better in HOP participants receiving DCP (treatment effect 7.29 points, 95% confidence interval 2.26 to 12.32, p 0.006). The median attack rate was also lower in HYP participants on DCP (0.9 vs 4.8) than in participants on placebo, but the difference in median attack rate was not significant (p 0.10). There were no significant effects of DCP on muscle strength or muscle mass in either trial. The most common adverse events in both trials were paresthesia (47% DCP vs 14% placebo, both trials combined) and confusion (19% DCP vs 7% placebo, both trials combined). Conclusions: DCP is effective in reducing the attack frequency, is safe, and improves quality of life in HOP periodic paralysis. Classification of evidence: These studies provide Class I evidence that DCP significantly reduces attack frequency in HOP but lacked the precision to support either efficacy or lack of efficacy of DCP in HYP

Papers, posters, and keynote presented at the 26th Polar Libraries Colloquy, hosted by the University of Alaska Fairbanks, Fairbanks, Alaska, USA 10 – 15 July 2016

Published July 2023 by the University of Alaska Anchorage, UAA/APU Consortium Library, and edited by Daria O. Carle. Copyright in individual papers is held by the contributors. A digital copy of this publication can be found at https://polarlibraries.org/colloquy-proceedings/ and in ScholarWorks, the University of Alaska’s Institutional Repository, https://scholarworks.alaska.edu/. A copy of the 2016 Colloquy program is also available at https://polarlibraries.org/colloquy-proceedings/. Further information on the Polar Libraries Colloquy, including details of membership and upcoming conferences, is available at https://polarlibraries.orgHistory of Polar Information Science / Working in Antarctica: Mapping a Changing Experience through the British Antarctic Survey / Géoindex+: A Geospatial Platform for Northern Historical and Research Data / Establishing Criteria for the Development of the “Northern Collection” at Université Laval’s Library: An Exploratory Approach / Introducing Two New Reserach Platforms: seaiceportal.de and expedition.awi.de (abstract only) / Establishing a Digital Library Service for the Inuvialuit Settlement Region / Changing Patterns of Polar Research / Mapping the Rescue of an Archive / Byrd 1933: Films from the Discovery Lecture Series / History of the Elmer E. Rasmuson Library and Its Rare Books Collection / A Roadmap to Navigate the Range of Polar Libraries, Databases, and Archives Now Available Online / Mapping Change with Finna in an Arctic Research Joint Library (paper not listed in program) / Mapping Chang in a Small Library Environment: From Reading Room to Communications Center (abstract only) / The Continued Evolution of the Cold Regions Bibliography Project: Current Status of the Antarctic Bibliography and the Antarctic Journal of the United States and its Predecessors / Connect the North: The Arctic Connect Project / Languages and Dialects in the Digital Library North (abstract only) / Bridging Arctic Indigenous Knowledge with the Digital World: Sharing Indigenous Ways of Knowing in Partnership with Arctic Communities (abstract only) / The Canadian Consortium for Arctic Data Interoperability (abstract and poster

Post-intervention Status in Patients With Refractory Myasthenia Gravis Treated With Eculizumab During REGAIN and Its Open-Label Extension

OBJECTIVE: To evaluate whether eculizumab helps patients with anti-acetylcholine receptor-positive (AChR+) refractory generalized myasthenia gravis (gMG) achieve the Myasthenia Gravis Foundation of America (MGFA) post-intervention status of minimal manifestations (MM), we assessed patients' status throughout REGAIN (Safety and Efficacy of Eculizumab in AChR+ Refractory Generalized Myasthenia Gravis) and its open-label extension. METHODS: Patients who completed the REGAIN randomized controlled trial and continued into the open-label extension were included in this tertiary endpoint analysis. Patients were assessed for the MGFA post-intervention status of improved, unchanged, worse, MM, and pharmacologic remission at defined time points during REGAIN and through week 130 of the open-label study. RESULTS: A total of 117 patients completed REGAIN and continued into the open-label study (eculizumab/eculizumab: 56; placebo/eculizumab: 61). At week 26 of REGAIN, more eculizumab-treated patients than placebo-treated patients achieved a status of improved (60.7% vs 41.7%) or MM (25.0% vs 13.3%; common OR: 2.3; 95% CI: 1.1-4.5). After 130 weeks of eculizumab treatment, 88.0% of patients achieved improved status and 57.3% of patients achieved MM status. The safety profile of eculizumab was consistent with its known profile and no new safety signals were detected. CONCLUSION: Eculizumab led to rapid and sustained achievement of MM in patients with AChR+ refractory gMG. These findings support the use of eculizumab in this previously difficult-to-treat patient population. CLINICALTRIALSGOV IDENTIFIER: REGAIN, NCT01997229; REGAIN open-label extension, NCT02301624. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that, after 26 weeks of eculizumab treatment, 25.0% of adults with AChR+ refractory gMG achieved MM, compared with 13.3% who received placebo

Minimal Symptom Expression' in Patients With Acetylcholine Receptor Antibody-Positive Refractory Generalized Myasthenia Gravis Treated With Eculizumab

The efficacy and tolerability of eculizumab were assessed in REGAIN, a 26-week, phase 3, randomized, double-blind, placebo-controlled study in anti-acetylcholine receptor antibody-positive (AChR+) refractory generalized myasthenia gravis (gMG), and its open-label extension