640 research outputs found
Doctors at Risk: A Problem As Viewed by Decision Analysis
The authors closely analyze a case in which a Peer Review Organization cited a physician for treatment with potential for significant adverse effect. They also critique the regulatory scheme under which peer review occurs and conclude that such regulation interferes with physicians\u27 primary obligations, fails to encourage cost-effective behavior and may decrease the quality of medical care
Bottomland Hardwood Management Demonstrations for South Carolina\u27s Lowcountry Forest Conservation Project
Southern bottomland hardwood forests occur on river floodplains of the southeastern United States, and ecological processes are driven by seasonal floodwaters from the river. Conservation and management of southeastern US coastal plain ecosystems is a priority in South Carolina’s Lowcountry Forest Conservation Project. The project is a partnership of Clemson University, Ducks Unlimited, the Joseph W. Jones Ecological Research Center, Lowcountry Open Land Trust, South Carolina Coastal Conservation League, The Conservation Fund, and The Nature Conservancy. A goal of this project is to create and disseminate economically and ecologically viable methods for conservation-based bottomland hardwood management on private lands, including restoration of degraded forests. Southern bottomland forests have been extensively altered by past cutting practices, as well as past agricultural use, indiscriminate cattle grazing, uncontrolled fires, and lack of attention to regeneration. Early harvest practices included high-grading to remove the most valuable stems, leaving behind the poorest. Repeating this practice through the years has resulted in under-stocked stands of low-quality trees in many forests. Four sites have been selected to establish demonstration areas to show people different management techniques that are currently being used to enhance timber and wildlife values. Funding for the project is provided by the Doris Duke Charitable Foundation. One model of bottomland hardwood management that can be used to achieve conservation goals in the southeastern United States is the system currently practiced by the Anderson-Tully Corporation in bottomland forests of the Mississippi River. The adaptation of this management method is presented here
Detection of Far-Infrared Water Vapor, Hydroxyl, and Carbon Monoxide Emissions from the Supernova Remnant 3C 391
We report the detection of shock-excited far-infrared emission of H2O, OH,
and CO from the supernova remnant 3C 391, using the ISO Long-Wavelength
Spectrometer. This is the first detection of thermal H2O and OH emission from a
supernova remnant. For two other remnants, W~28 and W~44, CO emission was
detected but OH was only detected in absorption. The observed H2O and OH
emission lines arise from levels within ~400 K of the ground state, consistent
with collisional excitation in warm, dense gas created after the passage of the
shock front through the dense clumps in the pre-shock cloud. The post-shock gas
we observe has a density ~2x10^5 cm^{-3} and temperature 100-1000 K, and the
relative abundances of CO:OH:H2O in the emitting region are 100:1:7 for a
temperature of 200 K. The presence of a significant column of warm H2O suggests
that the chemistry has been significantly changed by the shock. The existence
of significant column densities of both OH and H2O, which is at odds with
models for non-dissociative shocks into dense gas, could be due to
photodissociation of H2O or a mix of fast and slow shocks through regions with
different pre-shock density.Comment: AASTeX manuscript and 4 postscript figure
Aggregation Patterns in Stressed Bacteria
We study the formation of spot patterns seen in a variety of bacterial
species when the bacteria are subjected to oxidative stress due to hazardous
byproducts of respiration. Our approach consists of coupling the cell density
field to a chemoattractant concentration as well as to nutrient and waste
fields. The latter serves as a triggering field for emission of
chemoattractant. Important elements in the proposed model include the
propagation of a front of motile bacteria radially outward form an initial
site, a Turing instability of the uniformly dense state and a reduction of
motility for cells sufficiently far behind the front. The wide variety of
patterns seen in the experiments is explained as being due the variation of the
details of the initiation of the chemoattractant emission as well as the
transition to a non-motile phase.Comment: 4 pages, REVTeX with 4 postscript figures (uuencoded) Figures 1a and
1b are available from the authors; paper submitted to PRL
Long-term follow-up results of endoscopic treatment of gastroesophageal reflux disease with the MUSE TM endoscopic stapling device
Background
The initial 6-month data for MUSE™ (Medigus, Omer, Israel) endoscopic stapling device were reported (Zacherl et al. in Surg Endosc 29:220–229, 2015). The current study aims to evaluate the long-term clinical outcome of 37 patients who received endoscopic gastroesophageal reflux disease (GERD) treatment with the MUSE™ device.
Methods
Efficacy and safety data for 37 patients were analyzed at baseline, 6 months, and 4 years post-procedure. In one center (IU), efficacy and safety data were evaluated at baseline, 6 months post-procedure, and then annually up to 4 years.
Results
No new complications have been reported in our long-term analysis. The proportions of patients who remained off daily PPI were 83.8 % (31/37) at 6 months and 69.4 % (25/36) at 4 years post-procedure. GERD-Health Related Quality of Life (HRQL) scores (off PPI) were significantly decreased from baseline to 6 months and 4 years post-procedure. The daily dosage of GERD medications, measured as omeprazole equivalents (mean ± SD, mg), decreased from 66.1 ± 33.2 at baseline to 10.8 ± 15.9 at 6 months and 12.8 ± 19.4 at 4 years post-procedure (P < 0.01).
Conclusions
In our multi-center prospective study, the MUSE™ stapling device appears to be safe and effective in improving symptom scores as well as reducing PPI use in patients with GERD. These results appeared to be equal to or better than those of the other devices for endoluminal GERD therapy. Future studies with larger patient series, sham control group, and greater number of staples are awaited
Dust in Spiral Galaxies: Comparing Emission and Absorption to Constrain Small-Scale and Very Cold Structures
The detailed distribution of dust in the disks of spiral galaxies is
important to understanding the radiative transfer within disks, and to
measuring overall dust masses if significant quantities of dust are either very
opaque or very cold. We address this issue by comparing measures of dust
absorption, using the galaxy-overlap technique in the optical, with measures of
the dust grains' thermal emission from 50-2000 micron using ISOPHOT on board
ISO and SCUBA at the JCMT. We examine three spiral galaxies projected partially
in front of E/S0 galaxies --- AM1316-241, NGC 5545, and NGC 5091 (for NGC 5091
we have only optical and ISO data). Adopting an empirical exponential model for
the dust distribution, we compare column densities and dust masses derived from
the absorption and emission techniques. This comparison is sensitive to the
amount of dust mass in small, opaque structures, which would not contribute
strongly to area-weighted absorption measures, and to very cold dust, which
would contribute to optical absorption but provide only a small fraction of the
sub-mm emission. In AM1316-241, we find global dust masses of 2-5 x 10^7
M_solar, both techniques agreeing at the 50% level. NGC 5545 has about half
this dust mass. The concordance of dust masses is well within the errors
expected from our knowledge of the radial distribution of dust, and argues
against any dominant part of the dust mass being so cold or opaque. The 50-2000
micron data are well fitted by modified Planck functions with an emissivity law
beta=-2, at 21 +/- 2 K. We also present 12 micron ISOCAM observations of these
pairs.Comparison of H-alpha and 12 micron images of NGC 5545 indicate that
ISOCAM images are reliable tracers of star formation.Comment: 16 pages, 4 tables, 8 figures, in press for October Astronomical
Journa
- …