A review and evaluation of the Langley Research Center's Scientific and Technical Information Program. Results of phase 4: Knowledge and attitudes survey, academic and industrial personnel

Feedback from engineers and scientists in the academic and industrial community provided an assessment of the usage and perceived quality of NASA Langley generated STI and the familiarity and usage of selected NASA publications and services and identified ways to increase the accessibility of Langley STI. The questionnaire utilized both open and closed ended questions and was pretested for finalization. The questions were organized around the seven objectives for Phase IV. From a contact list of nearly 1,200 active industrial and academic researchers, approximately 600 addresses were verified. The 497 persons who agreed to participate were mailed questionnaires. The 381 completed questionnaires received by the cutoff date were analyzed. Based on the survey findings, recommendations were made for increasing the familiarity with and use of NASA and Langley STI and selected NASA publications and services. In addition, recommendations were made for increasing the accessibility of Langley STI

Faint Field Galaxies Around Bright Stars - A New Strategy for Imaging at the Diffraction Limit

This paper presents a new strategy for observing faint galaxies with high order natural guide star systems. We have imaged 5 high galactic latitude fields within the isoplanatic patch of bright stars (8.5 < R < 10.3 mag). The fields provide a rich set of faint field galaxies that are observable with a natural guide star adaptive optics system on a large telescope. Due to the small fields of many AO science cameras, these preliminary images are necessary to identify candidate galaxies. We present the photometry and positions for 78 objects (at least 40 galaxies) near five bright stars, appropriate for diffraction limited studies with the Keck and other AO systems on large ground-based telescopes. The K band seeing conditions in each field were excellent (0.4" - 0.7") allowing us to identify stars and estimate galaxy sizes. We also simulate AO images of field galaxies to determine the feasibility of infrared morphological studies at the diffraction limit. With new high order AO systems coming on line with 8-10 meter class telescopes, we believe these observations are invaluable in beginning to study faint galaxy populations at the diffraction limit.Comment: 15 pages, Latex, 9 figures. Accepted for publication in P.A.S.

A review and evaluation of the Langley Research Center's scientific and technical information program. Results of phase 1: Knowledge and attitudes survey, LaRC research personnel

The effectiveness of the Langley STI program was assessed using feedback obtained from Langley engineers and scientists. A survey research procedure was conducted in two stages. Personal interviews with 64 randomly selected Langley engineers and scientists were used to obtain information for questionnaire development. Data were then collected by means of the questionnaire which covered various aspects of the Langley STI program, utilized both open and closed ended questions and was pretested for finalization. The questions were organized around the six objectives for Phase 1. The completed questionnaires were analyzed. From the analysis of the data, recommendations were made for improving the Langley STI program

Morphological Evolution of Distant Galaxies from Adaptive Optics Imaging

We report here on a sample of resolved, infrared images of galaxies at z~0.5 taken with the 10-m Keck Telescope's Adaptive Optics (AO) system. We regularly achieve a spatial resolution of 0.05'' and are thus able to resolve both the disk and bulge components. We have extracted morphological information for ten galaxies and compared their properties to those of a local sample. The selection effects of both samples were explicitly taken into account in order to derive the unbiased result that disks at z~0.5 are ~0.6 mag arcsec^-2 brighter than, and about the same size as, local disks. The no-luminosity-evolution case is ruled out at 90% confidence. We also find, in a more qualitative analysis, that the bulges of these galaxies have undergone a smaller amount of surface brightness evolution and have also not changed significantly in size from z~0.5 to today. This is the first time this type of morphological evolution has been measured in the infrared and it points to the unique power of AO in exploring galaxy evolution.Comment: 27 pages, 7figures, 2 tables. Accepted for publication in the Astrophysical Journa

Exploring the Structure of Distant Galaxies with Adaptive Optics on the Keck-II Telescope

We report on the first observation of cosmologically distant field galaxies with an high order Adaptive Optics (AO) system on an 8-10 meter class telescope. Two galaxies were observed at 1.6 microns at an angular resolution as high as 50 milliarcsec using the AO system on the Keck-II telescope. Radial profiles of both objects are consistent with those of local spiral galaxies and are decomposed into a classic exponential disk and a central bulge. A star-forming cluster or companion galaxy as well as a compact core are detected in one of the galaxies at a redshift of 0.37+/-0.05. We discuss possible explanations for the core including a small bulge, a nuclear starburst, or an active nucleus. The same galaxy shows a peak disk surface brightness that is brighter than local disks of comparable size. These observations demonstrate the power of AO to reveal details of the morphology of distant faint galaxies and to explore galaxy evolution.Comment: 5 pages, Latex, 3 figures. Accepted for publication in P.A.S.

Classical generalized constant coupling model for geometrically frustrated antiferromagnets

A generalized constant coupling approximation for classical geometrically frustrated antiferromagnets is presented. Starting from a frustrated unit we introduce the interactions with the surrounding units in terms of an internal effective field which is fixed by a self consistency condition. Results for the magnetic susceptibility and specific heat are compared with Monte Carlo data for the classical Heisenberg model for the pyrochlore and kagome lattices. The predictions for the susceptibility are found to be essentially exact, and the corresponding predictions for the specific heat are found to be in very good agreement with the Monte Carlo results.Comment: 4 pages, 3 figures, 2 columns. Discussion about the zero T value of the pyrochlore specific heat correcte

Identification of publicly available data sources to inform the conduct of Health Technology Assessment in India

Background: Health technology assessment (HTA) provides a globally-accepted and structured approach to synthesising evidence for cost and clinical effectiveness alongside ethical and equity considerations to inform evidence-based priorities. India is one of the most recent countries to formally commit to institutionalising HTA as an integral component of the heath resource allocation decision-making process. The effective conduct of HTA depends on the availability of reliable data. Methods: We draw from our experience of collecting, synthesizing, and analysing health-related datasets in India and internationally, to highlight the complex requirements for undertaking HTA, and explore the availability of such data in India. We first outlined each of the core data components required for the conduct of HTA, and their availability in India, drawing attention to where data can be accessed, and different ways in which researchers can overcome the challenges of missing or low quality data. Results: We grouped data into the following categories: clinical efficacy; cost; epidemiology; quality of life; service use/consumption; and equity. We identified numerous large local data sources containing epidemiological information. There was a marked absence of other locally-collected data necessary for informing HTA, particularly data relating to cost, service use, and quality of life. Conclusions: The introduction of HTA into the health policy space in India provides an opportunity to comprehensively assess the availability and quality of health data capture across the country. While epidemiological information is routinely collected across India, other data inputs necessary for HTA are not readily available. This poses a significant bottleneck to the efficient generation and deployment of HTA into the health decision space. Overcoming these data gaps by strengthening the routine collection of comprehensive and verifiable health data will have important implications not only for embedding economic analyses into the priority setting process, but for strengthening the health system as a whole

Keck Adaptive Optics Imaging of 0.5<z<1 Field Galaxies from the Hubble Space Telescope Archive

We have employed natural guide star adaptive optics (AO) on the Keck II telescope to obtain near-infrared (H and K') images of three field galaxies, each of redshift greater than 0.5. These are among the highest-redshift non-active disk galaxies to be imaged with AO. Each of the galaxies was chosen because it had been observed previously with the Hubble Space Telescope (HST) Wide Field Planetary Camera 2 (WFPC2) by others. Our AO images in the near infrared (NIR) closely match both the depth and high spatial resolution of those optical data. Combining the archival V and I data with our new H and K' images potentially produces a long wavelength baseline at uniform resolution. The NIR data probe emission well longward of the 4000-Angstrom break at these redshifts, and provide stellar fluxes less contaminated by dust. We fit two-dimensional galaxy bulge-plus-disk models simultaneously in all bands, and compare stellar-population-synthesis modeling to the photometry of these separated components. This is an initial foray into combining HST and AO imaging to produce a high spatial-resolution multi-color dataset for a large sample of faint galaxies. Our pilot program shows that NIR AO images from large ground-based observatories, augmented by HST images in the optical, can in principle provide a powerful tool for the analysis of faint field galaxies. However, the AO data S/N will have to be increased, and AO PSFs need to be controlled more carefully than they were here.Comment: 22 pages, 16 Postscript figures. Accepted for publication in the ApJ Supplement