1,575 research outputs found
Unlocking the Doors to Patient Satisfaction in Pediatric Orthopaedics
Background Many hospitals continue to struggle to improve patient satisfaction as the identification of tangible quality improvement areas remains difficult Medicare hospital payments are linked to patient satisfaction and hospitals\u27 HCAHPS scores, which has contributed to the growing influence of patient satisfaction measures Investigation into the major drivers of patient satisfaction in the pediatric clinical arena has not been thoroughly pursued To determine the main drivers of patient experience in pediatric orthopaedics, we performed an analysis of patient satisfaction surveys collected from outpatient pediatric orthopaedic practices at 5 locations in 3 states Hypothesis: the patient-physician relationship is the most important factor in patients\u27 assessment of their experiences These results may have significance in aiding pediatric orthopaedic clinics in their Quality Assurance/Quality Improvement plans of enhancing the patient experiencehttps://jdc.jefferson.edu/pedsposters/1000/thumbnail.jp
The GALEX Ultraviolet Virgo Cluster Survey (GUViCS) III. The Ultraviolet Source Catalogs
In this paper we introduce the deepest and most extensive ultraviolet
extragalactic source catalogs of the Virgo Cluster area to date. Archival and
targeted GALEX imaging is compiled and combined to provide the deepest possible
coverage over ~120 deg^2 in the NUV (lambda_eff=2316 angstroms) and ~40 deg^2
in the FUV (lambda_eff=1539 angstroms) between 180 deg <= R.A. <= 195 deg and 0
deg <= Decl. <= 20 deg. We measure the integrated photometry of 1770 extended
UV sources of all galaxy types and use GALEX pipeline photometry for 1,230,855
point-like sources in the foreground, within, and behind the cluster. Extended
source magnitudes are reliable to m_UV ~22, showing ~0.01 sigma difference from
their asymptotic magnitudes. Point-like source magnitudes have a 1 sigma
standard deviation within ~0.2 mag down to m_uv ~23. The point-like source
catalog is cross-matched with large optical databases and surveys including the
SDSS DR9 (> 1 million Virgo Cluster sources), the Next Generation Virgo Cluster
Survey (NGVS; >13 million Virgo Cluster sources), and the NED (~30,000 sources
in the Virgo Cluster). We find 69% of the entire UV point-like source catalog
has a unique optical counterpart, 11% of which are stars and 129 are Virgo
cluster members neither in the VCC nor part of the bright CGCG galaxy catalog
(i.e., m_pg < 14.5). These data are collected in four catalogs containing the
UV extended sources, the UV point-like sources, and two catalogs each
containing the most relevant optical parameters of UV-optically matched
point-like sources for further studies from SDSS and NGVS. The GUViCS catalogs
provide a unique set of data for future works on UV and multiwavelength studies
in the cluster and background environments.Comment: 35 pages, 24 figures, 15 tables, Accepted for publication in A&
The Globular Cluster System of NGC 5128 II. Ages, Metallicities, Kinematics, and Formation
We present a study of the nearby post-merger giant elliptical galaxy, NGC
5128 (Centaurus A), in which we use the properties of its globular cluster (GC)
and planetary nebula (PN) systems to constrain its evolution. Using photometric
and spectroscopic data for 215 GCs presented in Paper I, we study trends in
age, metallicity, and kinematics for the GC system. We confirm that the GC
metallicity distribution is bimodal, and show that these two sub-populations
have different properties. Using spectral line index measurements of the
brightest clusters, the metal-poor GCs have old ages like the Milky Way
globular clusters, while the metal-rich GCs have H-beta line-strengths that
could be interpreted as a mean age of ~5 (+3/-2) Gyr. Both populations appear
to have [Mg/Fe] ratios consistent with that of the Galactic GC system, although
this quantity is not very well-constrained. The kinematics of the metal-rich
GCs are similar to those of the planetary nebulae, exhibiting significant
rotation about a misaligned axis, while the metal-poor GCs have a higher
velocity dispersion and show a weaker kinematic correlation with the field
stars. The total gravitating mass of NGC 5128 derived from the GCs is in
excellent agreement with the value derived from stellar (PN) kinematics. We
suggest that these and other data support a picture in which the main body of
NGC 5128 was formed 3-8 Gyr ago by the dissipational merger of two unequal-mass
disk galaxies supplemented by the continual accretion of both gas-rich and
gas-poor satellites.Comment: 15 pages, 21 figures (figures 14-20 best viewed in color), accepted
for publication in the Astrophysical Journa
The Next Generation Virgo Cluster Survey. IX. Estimating the Efficiency of Galaxy Formation on the Lowest-Mass Scales
The Next Generation Virgo Cluster Survey has recently determined the
luminosity function of galaxies in the core of the Virgo cluster down to
unprecedented magnitude and surface brightness limits. Comparing simulations of
cluster formation to the derived central stellar mass function, we attempt to
estimate the stellar-to-halo-mass ratio (SHMR) for dwarf galaxies, as it would
have been before they fell into the cluster. This approach ignores several
details and complications, e.g., the contribution of ongoing star formation to
the present-day stellar mass of cluster members, and the effects of adiabatic
contraction and/or violent feedback on the subhalo and cluster potentials. The
final results are startlingly simple, however; we find that the trends in the
SHMR determined previously for bright galaxies appear to extend down in a
scale-invariant way to the faintest objects detected in the survey. These
results extend measurements of the formation efficiency of field galaxies by
two decades in halo mass, or five decades in stellar mass, down to some of the
least massive dwarf galaxies known, with stellar masses of .Comment: 18 pages, 12 figures; published in ApJ July 1st 201
In-situ strain tuning of the Dirac surface states in Bi2Se3 films
Elastic strain has the potential for a controlled manipulation of the band
gap and spin-polarized Dirac states of topological materials, which can lead to
pseudo-magnetic-field effects, helical flat bands and topological phase
transitions. However, practical realization of these exotic phenomena is
challenging and yet to be achieved. Here, we show that the Dirac surface states
of the topological insulator Bi2Se3 can be reversibly tuned by an externally
applied elastic strain. Performing in-situ x-ray diffraction and in-situ
angle-resolved photoemission spectroscopy measurements during tensile testing
of epitaxial Bi2Se3 films bonded onto a flexible substrate, we demonstrate
elastic strains of up to 2.1% and quantify the resulting reversible changes in
the topological surface state. Our study establishes the functional
relationship between the lattice and electronic structures of Bi2Se3 and, more
generally, demonstrates a new route toward momentum-resolved mapping of
strain-induced band structure changes
The Next Generation Virgo Cluster Survey. VI. The Kinematics of Ultra-compact Dwarfs and Globular Clusters in M87
The origin of ultra-compact dwarfs (UCDs)--objects larger and more massive
than typical globular clusters (GCs), but more compact than typical dwarf
galaxies--has been hotly debated in the 15 years since their discovery. Even
whether UCDs should be considered galactic in origin, or simply the most
extreme GCs, is not yet settled. We present the dynamical properties of 97
spectroscopically confirmed UCDs (rh >~10 pc) and 911 GCs associated with
central cD galaxy of the Virgo cluster, M87. Our UCDs, of which 89% have M_star
> ~2X10^6 M_sun and 92% are as blue as the classic blue GCs, nearly triple the
sample of previous confirmed Virgo UCDs, providing by far the best opportunity
for studying the global dynamics of a UCD system. We found that (1) UCDs have a
surface number density profile that is shallower than that of the blue GCs in
the inner ~ 70 kpc and as steep as that of the red GCs at larger radii; (2)
UCDs exhibit a significantly stronger rotation than the GCs, and the blue GCs
seem to have a velocity field that is more consistent with that of the
surrounding dwarf ellipticals than with that of UCDs; (3) UCDs have a radially
increasing orbital anisotropy profile, and are tangentially-biased at radii < ~
40 kpc and radially-biased further out. In contrast, the blue GCs become more
tangentially-biased at larger radii beyond ~ 40 kpc; (4) GCs with M_star >
2X10^6 M_sun have rotational properties indistinguishable from the less massive
ones, suggesting that it is the size, instead of mass, that differentiates UCDs
from GCs as kinematically distinct populations. We conclude that most UCDs in
M87 are not consistent with being merely the most luminous and extended
examples of otherwise normal GCs. The radially-biased orbital structure of UCDs
at large radii is in general agreement with the "tidally threshed dwarf galaxy"
scenario.Comment: 27 pages, 21 figures. To appear in The Astrophysical Journa
The Origin of the Mass--Metallicity Relation: Insights from 53,000 Star-Forming Galaxies in the SDSS
We utilize Sloan Digital Sky Survey imaging and spectroscopy of ~53,000
star-forming galaxies at z~0.1 to study the relation between stellar mass and
gas-phase metallicity. We derive gas-phase oxygen abundances and stellar masses
using new techniques which make use of the latest stellar evolutionary
synthesis and photoionization models. We find a tight (+/-0.1 dex) correlation
between stellar mass and metallicity spanning over 3 orders of magnitude in
stellar mass and a factor of 10 in metallicity. The relation is relatively
steep from 10^{8.5} - 10^{10.5} M_sun, in good accord with known trends between
luminosity and metallicity, but flattens above 10^{10.5} M_sun. We use indirect
estimates of the gas mass based on the H-alpha luminosity to compare our data
to predictions from simple closed box chemical evolution models. We show that
metal loss is strongly anti-correlated with baryonic mass, with low mass dwarf
galaxies being 5 times more metal-depleted than L* galaxies at z~0.1. Evidence
for metal depletion is not confined to dwarf galaxies, but is found in galaxies
with masses as high as 10^{10} M_sun. We interpret this as strong evidence both
of the ubiquity of galactic winds and of their effectiveness in removing metals
from galaxy potential wells.Comment: ApJ accepted, 15 pages, 9 figures, emulateapj.st
The Sloan Digital Sky Survey: The Cosmic Spectrum and Star-Formation History
We present a determination of the `Cosmic Optical Spectrum' of the Universe,
i.e. the ensemble emission from galaxies, as determined from the red-selected
Sloan Digital Sky Survey main galaxy sample and compare with previous results
of the blue-selected 2dF Galaxy Redshift Survey. Broadly we find good agreement
in both the spectrum and the derived star-formation histories. If we use a
power-law star-formation history model where star-formation rate out to z=1, then we find that of 2 to 3 is still the most
likely model and there is no evidence for current surveys missing large amounts
of star formation at high redshift. In particular `Fossil Cosmology' of the
local universe gives measures of star-formation history which are consistent
with direct observations at high redshift. Using the photometry of SDSS we are
able to derive the cosmic spectrum in absolute units (i.e.^{-1}^{-3}\Msun/\Lsun\omstars h = 0.0025\alpha\Msun^{-1}^{-3}$ today.Comment: 17 pages, 11 figures, ApJ in press (April 10th 2003
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