1,953 research outputs found
Description of a new genus and species of hummingbird from Panama
Since January, 1911, Mr. E. A. Goldman, of the Biological Survey, U.S.Department of Agriculture, has been detailed to the Smithsonian Biological Survey of the Panama Canal Zone to collect mammals and birds in the Canal Zone and adjacent parts of Panama... (Document contains 4 pages
The Endowment Effect in a Public Good Experiment
Previous tests of the endowment effect have usually observed WTA-WTP disparities. Here, a public good experiment is employed. Both account framing and duration framing treatments are introduced to alter subjects’ perceived control over an initial endowment. Results do not indicate that preferences shift in a way consistent with the endowment effect.endowment effect, public good, willingness to pay
Two new subspecies of birds from Panama
While working on the Smithsonian Biological Survey of the Canal Zone, Mr. E. A. Goldman of the Biological Survey, United States Department of Agriculture, collected specimens of two undescribed subspecies of birds which are characterized below. (Document contains 3 pages
Descriptions of new genera, species and subspecies of birds from Panama, Colombia, and Ecuador
The first of January, 1912, E. A. Goldman, of the Biological Survey, Department of Agriculture, was again detailed on the Smithsonian Biological Survey of the Canal Zone. He returned to Panama in January and remained there until the last of June passing most of this period in collecting birds and mammals on the slopes of Mount Pirri on the Pacific side of eastern Panama, near the Colombian border...(Document contains 27 pages
Descriptions of two new species of nun birds from Panama
Two new species of Monasa are among the interesting birds collected by E. A. Goldman while working on the Smithsonian Biological Survey of Panama during the winter of 1911. They were collected at the same locality on the base of Cerro Azul, northwest from Chepo, and only a single specimen of each was obtained. No others were seen during the entire season in the Canal Zone and adjacent territory...(Document contains 4 pages
Exploring the Chemical Composition and Double Horizontal Branch of the Bulge Globular Cluster NGC 6569
Photometric and spectroscopic analyses have shown that the Galactic bulge
cluster Terzan 5 hosts several populations with different metallicities and
ages that manifest as a double red horizontal branch (HB). A recent
investigation of the massive bulge cluster NGC 6569 revealed a similar, though
less extended, HB luminosity split, but little is known about the cluster's
detailed chemical composition. Therefore, we have used high-resolution spectra
from the Magellan-M2FS and VLT-FLAMES spectrographs to investigate the chemical
compositions and radial velocity distributions of red giant branch and HB stars
in NGC 6569. We found the cluster to have a mean heliocentric radial velocity
of -48.8 km/s (sigma = 5.3 km/s; 148 stars) and a mean [Fe/H] =-0.87 dex (19
stars), but the cluster's 0.05 dex [Fe/H] dispersion precludes a significant
metallicity spread. NGC 6569 exhibits light- and heavy-element distributions
that are common among old bulge/inner Galaxy globular clusters, including clear
(anti)correlations between [O/Fe], [Na/Fe], and [Al/Fe]. The light-element data
suggest that NGC 6569 may be composed of at least two distinct populations, and
the cluster's low mean [La/Eu] = -0.11 dex indicates significant pollution with
r-process material. We confirm that both HBs contain cluster members, but
metallicity and light-element variations are largely ruled out as sources for
the luminosity difference. However, He mass fraction differences as small as
delta Y ~ 0.02 cannot be ruled out and may be sufficient to reproduce the
double HB.Comment: 72 pages, 14 figures, 8 tables; published in The Astronomical
Journal; electronic versions of all tables are available in the published
versio
A Chemical Composition Survey of the Iron-Complex Globular Cluster NGC 6273 (M 19)
Recent observations have shown that a growing number of the most massive
Galactic globular clusters contain multiple populations of stars with different
[Fe/H] and neutron-capture element abundances. NGC 6273 has only recently been
recognized as a member of this "iron-complex" cluster class, and we provide
here a chemical and kinematic analysis of > 300 red giant branch (RGB) and
asymptotic giant branch (AGB) member stars using high resolution spectra
obtained with the Magellan-M2FS and VLT-FLAMES instruments. Multiple lines of
evidence indicate that NGC 6273 possesses an intrinsic metallicity spread that
ranges from about [Fe/H] = -2 to -1 dex, and may include at least three
populations with different [Fe/H] values. The three populations identified here
contain separate first (Na/Al-poor) and second (Na/Al-rich) generation stars,
but a Mg-Al anti-correlation may only be present in stars with [Fe/H] > -1.65.
The strong correlation between [La/Eu] and [Fe/H] suggests that the s-process
must have dominated the heavy element enrichment at higher metallicities. A
small group of stars with low [alpha/Fe] is identified and may have been
accreted from a former surrounding field star population. The cluster's large
abundance variations are coupled with a complex, extended, and multimodal blue
horizontal branch (HB). The HB morphology and chemical abundances suggest that
NGC 6273 may have an origin that is similar to omega Cen and M 54.Comment: Accepted for Publication in The Astrophysical Journal; 50 pages; 18
figures; 8 tables; higher resolution figures are available upon request or in
the published journal articl
Evidence for a Disk-Jet Interaction in the Microquasar GRS 1915+105
We report simultaneous X-ray and infrared (IR) observations of the Galactic
microquasar GRS1915+105 using XTE and the Palomar 200-inch telescope on August
13-15, 1997 UTC. During the last two nights, the microquasar GRS 1915+105
exhibited quasi-regular X-ray/infrared (IR) flares with a spacing of
minutes. While the physical mechanism triggering the flares is currently
unknown, the one-to-one correspondence and consistent time offset between the
X-ray and IR flares establish a close link between the two. At late times in
the flares the X-ray and IR bands appear to ``decouple'', with the X-ray band
showing large-amplitude fast oscillations while the IR shows a much smoother,
more symmetrical decline. In at least three cases, the IR flare has returned to
near its minimum while the X-rays continue in the elevated oscillatory state,
ruling out thermal reprocessing of the X-ray flux as the source of IR flare.
Furthermore, observations of similar IR and radio flares by Fender et al.
(1997) imply that the source of the IR flux in such flares is synchrotron
emission. The common rise and subsequent decoupling of the X-ray and IR flux
and probable synchrotron origin of the IR emission is consistent with a
scenario wherein the IR flux originates in a relativistic plasma which has been
ejected from the inner accretion disk. In that case, these simultaneous
X-ray/IR flares from a black-hole/relativistic-jet system are the first clear
observational evidence linking of the time-dependent interaction of the jet and
the inner disk in decades of quasar and microquasar studies.Comment: 15 pages, incl. 3 figures. To appear in ApJ Letter
Developing a pressure ulcer risk factor minimum data set and risk assessment framework
AIM: To agree a draft pressure ulcer risk factor Minimum Data Set to underpin the development of a new evidenced-based Risk Assessment Framework.BACKGROUND: A recent systematic review identified the need for a pressure ulcer risk factor Minimum Data Set and development and validation of an evidenced-based pressure ulcer Risk Assessment Framework. This was undertaken through the Pressure UlceR Programme Of reSEarch (RP-PG-0407-10056), funded by the National Institute for Health Research and incorporates five phases. This article reports phase two, a consensus study.DESIGN: Consensus study.METHOD: A modified nominal group technique based on the Research and Development/University of California at Los Angeles appropriateness method. This incorporated an expert group, review of the evidence and the views of a Patient and Public Involvement service user group. Data were collected December 2010-December 2011.FINDINGS: The risk factors and assessment items of the Minimum Data Set (including immobility, pressure ulcer and skin status, perfusion, diabetes, skin moisture, sensory perception and nutrition) were agreed. In addition, a draft Risk Assessment Framework incorporating all Minimum Data Set items was developed, comprising a two stage assessment process (screening and detailed full assessment) and decision pathways.CONCLUSION: The draft Risk Assessment Framework will undergo further design and pre-testing with clinical nurses to assess and improve its usability. It will then be evaluated in clinical practice to assess its validity and reliability. The Minimum Data Set could be used in future for large scale risk factor studies informing refinement of the Risk Assessment Framework
Magellan/M2FS and MMT/Hectochelle Spectroscopy of Dwarf Galaxies and Faint Star Clusters within the Galactic Halo
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