Paper Session II-A - Free-Flying Platforms for the International Space Station: Large Aperture Science at Medium-Explorer Cost

We present the concept of a reusable science probe based at the International Space Station (ISS). A wide range of unique scientific and technical investigations will be enabled through the large aperture and high mass capabilities of the platform. The ISS infrastructure is used for servicing the spacecraft and/or scientific instrument, as well as upgrading the scientific payload. During the data gathering phase, envisioned to last six months to two years, the spacecraft will be a free-flyer in the ISS orbit, avoiding operational constraints imposed by the ISS environment and allowing full control of the experiment by the investigation team. Periodic docking with the ISS provides the servicing capability. A limited spare parts cache can be provided by the ISS “mother ship” using excess STS payload capacity to this frequent-flyer destination. By eliminating the need for mission-unique spacecraft and operations infrastructure for a wide range of missions, a tremendous return on investment can be realized

Charge-coupled device for low background observations

A charge-coupled device with a low-emissivity metal layer located between a sensing layer and a substrate provides reduction in ghost images. In a typical charge-coupled device of a silicon sensing layer, a silicon dioxide insulating layer, with a glass substrate and a metal carrier layer, a near-infrared photon, not absorbed in the first pass, enters the glass substrate, reflects from the metal carrier, thereby returning far from the original pixel in its entry path. The placement of a low-emissivity metal layer between the glass substrate and the sensing layer reflects near infrared photons before they reach the substrate so that they may be absorbed in the silicon nearer the pixel of their points of entry so that the reflected ghost image is coincident with the primary image for a sharper, brighter image

Data compression using Chebyshev transform

The present invention is a method, system, and computer program product for implementation of a capable, general purpose compression algorithm that can be engaged on the fly. This invention has particular practical application with time-series data, and more particularly, time-series data obtained form a spacecraft, or similar situations where cost, size and/or power limitations are prevalent, although it is not limited to such applications. It is also particularly applicable to the compression of serial data streams and works in one, two, or three dimensions. The original input data is approximated by Chebyshev polynomials, achieving very high compression ratios on serial data streams with minimal loss of scientific information

Uncertainty as a Key Influence in the Decision To Admit Patients with Transient Ischemic Attack

Background Patients with transient ischemic attacks (TIA) are at high risk of subsequent vascular events. Hospitalization improves quality of care, yet admission rates for TIA patients vary considerably. Objectives We sought to identify factors associated with the decision to admit patents with TIA. Design We conducted a secondary analysis of a prior study’s data including semi-structured interviews, administrative data, and chart review. Participants We interviewed multidisciplinary clinical staff involved with TIA care. Administrative data included information for TIA patients in emergency departments or inpatient settings at VA medical centers (VAMCs) for fiscal years (FY) 2011 and 2014. Chart reviews were conducted on a subset of patients from 12 VAMCs in FY 2011. Approach For the qualitative data, we focused on interviewees’ responses to the prompt: “Tell me what influences you in the decision to or not to admit TIA patients.” We used administrative data to identify admission rates and chart review data to identify ABCD2 scores (a tool to classify stroke risk after TIA). Key Results Providers’ decisions to admit TIA patients were related to uncertainty in several domains: lack of a facility TIA-specific policy, inconsistent use of ABCD2 score, and concerns about facilities’ ability to complete a timely workup. There was a disconnect between staff perceptions about TIA admission and facility admission rates. According to chart review data, staff at facilities with higher admission rates in FY 2011 reported consistent reliance on ABCD2 scores and related guidelines in admission decision-making. Conclusions Many factors contributed to decisions regarding admitting a patient with TIA; however, clinicians’ uncertainty appeared to be a key driver. Further quality improvement interventions for TIA care should focus on facility adoption of TIA protocols to address uncertainty in TIA admission decision-making and to standardize timely evaluation of TIA patients and delivery of secondary prevention strategies

The Missed Patient With Diabetes: How access to health care affects the detection of diabetes

OBJECTIVE—This study examined the association between access to health care and three classifications of diabetes status: diagnosed, undiagnosed, and no diabetes

Far Ultraviolet Observations of the Dwarf Nova VW Hyi in Quiescence

We present a 904-1183 A spectrum of the dwarf nova VW Hydri taken with the Far Ultraviolet Spectroscopic Explorer during quiescence, eleven days after a normal outburst, when the underlying white dwarf accreter is clearly exposed in the far ultraviolet. However, model fitting show that a uniform temperature white dwarf does not reproduce the overall spectrum, especially at the shortest wavelengths. A better approximation to the spectrum is obtained with a model consisting of a white dwarf and a rapidly rotating ``accretion belt''. The white dwarf component accounts for 83% of the total flux, has a temperature of 23,000K, a v sin i = 400 km/s, and a low carbon abundance. The best-fit accretion belt component accounts for 17% of the total flux, has a temperature of about 48,000-50,000K, and a rotation rate Vrot sin i around 3,000-4,000 km/s. The requirement of two components in the modeling of the spectrum of VW Hyi in quiescence helps to resolve some of the differences in interpretation of ultraviolet spectra of VW Hyi in quiescence. However, the physical existence of a second component (and its exact nature) in VW Hyi itself is still relatively uncertain, given the lack of better models for spectra of the inner disk in a quiescent dwarf nova.Comment: 6 figures, 10 printed page in the journal, to appear in APJ, 1 Sept. 2004 issue, vol. 61

IDA evaluation handbook: A practical guide and tools for evaluation of pioneering IDA projects

This IDA Evaluation Handbook is designed as a practical guide with tools for emergent, pioneering IDA (Individual Development Accounts) projects. The goal of this Handbook is to promote early evaluations of IDAs and learn as much as possible from each project