3,918 research outputs found
Accountable Care Organizations in Medicare and the Private Sector: A Status Update
Provides an overview of accountable care organizations - provider networks with financial incentives to slow spending growth while maintaining or improving quality of care - and their state of adoption, as well as key considerations
Long Duration Exposure Facility: A general overview
The Long Duration Exposure Facility (LDEF) is a large, low-cost, reusable, unmanned, free-flying spacecraft which accommodates technology, science, and applications experiments for long-term exposure to the space environment. The LDEF was designed and built by the NASA Langley Research Center (LaRC) for NASA's Office of Aeronautics and Space Technology. Specifically, the LDEF was designed to transport experiments into space via the Space Shuttle, to free fly in Earth orbit for an extended period, and be retrieved on a later Space Shuttle flight allowing experiments to be returned to Earth for postflight analysis in the laboratory. The LDEF with a full complement of experiments was placed in Earth orbit in April 1984 by Challenger and retrieved from orbit in January 1990 by Columbia. A general overview of the LDEF, its mission, systems, experiments, and operations is presented. Excerpts from various NASA documents are extensively used
DI in the outer Galaxy
We report on a deep search with the Westerbork Synthesis Radio Telescope
towards the galactic anticenter for the 327 MHz hyperfine transition of DI.
This is a favorable direction for a search because: (i) the HI optical depth is
high due to velocity crowding; (ii) the observed molecular column density is
low (implying that most of the deuterium would probably be in atomic form,
rather than in HD); and (iii) the stellar reprocessing should be minimal.
Our observations are about a factor of two more sensitive than previous
searches for DI in this direction. We detect a low significance (about 4 sigma)
feature, consistent in both amplitude and center frequency with an emission
feature reported previously (Blitz & Heiles 1987). If this is the DI line, then
the implied N_D/N_H of 3.9+/-1.0 x 10^-5 is comparable to the inferred
pre-solar deuterium abundance. Our observation is consistent with the recent
low measurements of D/H towards high-redshift Lyman-limit systems. On the other
hand, if the reports of high DI abundance (about 24 x 10^-5) in such systems
are confirmed, then our observations imply that even in regions of reduced star
formation within the outer Galaxy, the DI abundance has been reduced by a
factor of about 6 from the primordial abundance.Comment: 4 page LaTeX requires l-aa.sty and psfig.sty, 1 ps figure. Accepted
for publication in A&A Letter
Will the Patient-Centered Medical Home Transform the Delivery of Health Care?
Explores various definitions of the medical home model, its components, rationale, effect on primary care, issues for implementation such as costs and payment methods, evidence of effectiveness, and healthcare reform provisions promoting it
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