280 research outputs found
Impact of Outpatient vs Inpatient ABSSSI Treatment on Outcomes: A Retrospective Observational Analysis of Medical Charts Across US Emergency Departments
Background
The objective of this study was to characterize treatment of patients with acute bacterial skin and skin structure infections (ABSSSIs) and describe the association between hospital admission and emergency department (ED) visits or readmissions within 30 days after initial episode of care (IEC).
Methods
This was a retrospective, observational, cohort study of adults with ABSSSI who presented to an ED between July 1, 2012, and June 30, 2013. Patient, health care facility, and treatment characteristics, including unplanned ED visits or readmissions, were obtained through manual chart review and abstraction. Adjusted logistic regression analysis examined likelihood of all-cause unplanned ED visits or readmissions between admitted and nonadmitted patients.
Results
Records from 1527 ED visits for ABSSSI from 40 centers were reviewed (admitted, n = 578 [38%]; nonadmitted, n = 949 [62%]). Admitted patients were typically older (mean age, 52.2 years vs 43.0 years), more likely to be morbidly obese (body mass index \u3e 40 kg/m2; 17.3% vs 9.1%), and had more comorbidities (Charlson Comorbidity Index ≥ 4; 24.4% vs 6.8%) compared with those not admitted. In the primary analysis, adjusted logistic regression, controlling for comorbidities and severity of illness, demonstrated that there was a similar likelihood of all-cause unplanned ED visits or readmissions between admitted and nonadmitted patients (odds ratio, 1.03; 95% confidence interval, 0.74–1.43; P = .87).
Conclusions
ABSSSI treatment pathways leveraging outpatient treatment vs hospital admission support similar likelihood of unplanned 30-day ED visits or readmissions, an important clinical outcome and quality metric at US hospitals. Further research regarding the decision criteria around hospital admission to avoid potentially unnecessary hospitalizations is warranted
Geometrical tests of cosmological models. II. Calibration of rotational widths and disc scaling relations
This series of papers is dedicated to a new technique to select galaxies that
can act as standard rods and standard candles in order to perform geometrical
tests on large samples of high redshift galaxies to constrain different
cosmological parameters. The goals of this paper are (1) to compare different
rotation indicators in order to understand the relation between rotation
velocities extracted from observations of the Halpha line and the [OII]3727
line, and (2) determine the scaling relations between physical size, surface
brightness and magnitude of galaxies and their rotation velocity using the
SFI++, a large catalog of nearby galaxies observed at I-band. A good
correlation is observed between the rotation curve-derived velocities of the
Halpha and [OII] observations, as well as between those calculated from
velocity histograms, justifying the direct comparison of velocities measured
from Halpha rotation curves in nearby galaxies and from [OII] line widths at
higher redshifts. To provide calibration for the geometrical tests, we give
expressions for the different scaling relations between properties of galaxies
(size, surface brightness, magnitude) and their rotation speeds. Apart from the
Tully-Fisher relation, we derive the size-rotation velocity and surface
brightness-rotation velocity relations with unprecedentedly small scatters. We
show how the best size-rotation velocity relation is derived when size is
estimated not from disc scale lengths but from the isophotal diameter r23.5,
once these have been corrected for inclination and extinction effects.Comment: 14 pages and 10 figures. A&A submitte
Peculiar velocities of galaxies and clusters
We present a simple model for the shape of the distribution function of
galaxy peculiar velocities. We show how both nonlinear and linear theory terms
combine to produce a distribution which has an approximately Gaussian core with
exponential wings. The model is easily extended to study how the statistic
depends on the type of particle used to trace the velocity field (dark matter
particles, dark matter haloes, galaxies), and on the density of the environment
in which the test particles are. Comparisons with simulations suggest that our
model is accurate. We also show that the evolution of the peculiar velocities
depends on the local, rather than the global density. Since clusters populate
denser regions on average, using cluster velocities with the linear theory
scaling may lead to an overestimate of the global value of Omega. Conversely,
using linear theory with the global value of Omega to scale cluster velocities
from the initial to the present time results in an underestimate of their true
velocities. In general, however, the directions of motions of haloes are rather
well described by linear theory. Our results help to simplify models of
redshift-space distortions considerably.Comment: 18 pages, 18 figures, submitted to MNRAS 2000 July 1
The clustering of galaxies as a function of their photometrically-estimated atomic gas content
We introduce a new photometric estimator of the HI mass fraction (M_HI/M_*)
in local galaxies, which is a linear combination of four parameters: stellar
mass, stellar surface mass density, NUV-r colour, and g-i colour gradient. It
is calibrated using samples of nearby galaxies (0.025<z<0.05) with HI line
detections from the GASS and ALFALFA surveys, and it is demonstrated to provide
unbiased M_HI/M_* estimates even for HI-rich galaxies. We apply this estimator
to a sample of ~24,000 galaxies from the SDSS/DR7 in the same redshift range.
We then bin these galaxies by stellar mass and HI mass fraction and compute
projected two point cross-correlation functions with respect to a reference
galaxy sample. Results are compared with predictions from current semi-analytic
models of galaxy formation. The agreement is good for galaxies with stellar
masses larger than 10^10 M_sun, but not for lower mass systems. We then extend
the analysis by studying the bias in the clustering of HI-poor or HI-rich
galaxies with respect to galaxies with normal HI content on scales between 100
kpc and ~5 Mpc. For the HI-deficient population, the strongest bias effects
arise when the HI-deficiency is defined in comparison to galaxies of the same
stellar mass and size. This is not reproduced by the semi-analytic models,
where the quenching of star formation in satellites occurs by "starvation" and
does not depend on their internal structure. HI-rich galaxies with masses
greater than 10^10 M_sun are found to be anti-biased compared to galaxies with
"normal" HI content. Interestingly, no such effect is found for lower mass
galaxies.Comment: 14 pages, 10 figures, accepted for publication in MNRAS, slightly
revised in the tex
The Debrisoft ® monofilament debridement pad for use in acute or chronic wounds: A NICE medical technology guidance
As part of its Medical Technology Evaluation Programme, the National Institute for Health and Care Excellence (NICE) invited a manufacturer to provide clinical and economic evidence for the evaluation of the Debrisoft ® monofilament debridement pad for use in acute or chronic wounds. The University of Birmingham and Brunel University, acting as a consortium, was commissioned to act as an External Assessment Centre (EAC) for NICE, independently appraising the submission. This article is an overview of the original evidence submitted, the EAC’s findings and the final NICE guidance issued. The sponsor submitted a simple cost analysis to estimate the costs of using Debrisoft® to debride wounds compared with saline and gauze, hydrogel and larvae. Separate analyses were conducted for applications in home and applications in a clinic setting. The analysis took an UK National Health Service (NHS) perspective. It incorporated the costs of the technologies and supplementary technologies (such as dressings) and the costs of their application by a district nurse. The sponsor concluded that Debrisoft® was cost saving relative to the comparators. The EAC made amendments to the sponsor analysis to correct for errors and to reflect alternative assumptions. Debrisoft® remained cost saving in most analyses and savings ranged from £77 to £222 per patient compared with hydrogel, from £97 to £347 compared with saline and gauze, and from £180 to £484 compared with larvae depending on the assumptions included in the analysis and whether debridement took place in a home or clinic setting. All analyses were severely limited by the available data on effectiveness, in particular a lack of comparative studies and that the effectiveness data for the comparators came from studies reporting different clinical endpoints compared with Debrisoft®. The Medical Technologies Advisory Committee made a positive recommendation for adoption of Debrisoft® and this has been published as a NICE medical technology guidance (MTG17).The Birmingham and Brunel Consortium is funded by NICE to act as an External Assessment Centre for the Medical Technologies Evaluation Programme
The Low Surface Brightness Extent of the Fornax Cluster
We have used a large format CCD camera to survey the nearby Fornax cluster
and its immediate environment for low luminosity low surface brightness
galaxies. Recent observations indicate that these are the most dark matter
dominated galaxies known and so they are likely to be a good tracer of the dark
matter in clusters. We have identified large numbers of these galaxies
consistent with a steep faint end slope of the luminosity function (alpha~ -2)
down to MB ~ -12. These galaxies contribute almost the same amount to the total
cluster light as the brighter galaxies and they have a spatial extent that is
some four times larger. They satisfy two of the important predictions of N-body
hierarchical simulations of structure formation using dark halos. The
luminosity (mass ?) function is steep and the mass distribution is more
extended than that defined by the brighter galaxies. We also find a large
concentration of low surface brightness galaxies around the nearby galaxy
NGC1291.Comment: 16 pages, 6 figure
The Tully-Fisher Relation for 25,000 SDSS Galaxies as Function of Environment
We construct Tully-Fisher relationships (TFRs) in the , , , and
bands and stellar mass TFRs (smTFRs) for a sample of late spiral
type galaxies (with ) from the Sloan Digital Sky Survey (SDSS)
and study the effects of environment on the relation. We use SDSS-measured
Balmer emission line widths, , as a proxy for disc circular
velocity, . A priori it is not clear whether we can construct
accurate TFRs given the small diameter of the fibres used for SDSS
spectroscopic measurements. However, we show by modelling the H
emission profile as observed through a aperture that for galaxies at
appropriate redshifts () the fibres sample enough of the disc to
obtain a linear relationship between and ,
allowing us to obtain a TFR and to investigate dependence on other variables.
We also develop a methodology for distinguishing between astrophysical and
sample bias in the fibre TFR trends. We observe the well-known steepening of
the TFR in redder bands in our sample. We divide the sample of galaxies into
four equal groups using projected neighbour density () quartiles and
find no significant dependence on environment, extending previous work to a
wider range of environments and a much larger sample. Having demonstrated that
we can construct SDSS-based TFRs is very useful for future applications because
of the large sample size available.Comment: accepted for publication in MNRAS. 15 pages, 12 figure
An Investigation of Sloan Digital Sky Survey Imaging Data and Multi-Band Scaling Relations of Spiral Galaxies (with Dynamical Information)
We have compiled a sample of 3041 spiral galaxies with multi-band gri imaging
from the Sloan Digital Sky Survey (SDSS) Data Release 7 and available galaxy
rotational velocities derived from HI line widths. We compare the data products
provided through the SDSS imaging pipeline with our own photometry of the SDSS
images, and use the velocities (V) as an independent metric to determine ideal
galaxy sizes (R) and luminosities (L). Our radial and luminosity parameters
improve upon the SDSS DR7 Petrosian radii and luminosities through the use of
isophotal fits to the galaxy images. This improvement is gauged via VL and RV
relations whose respective scatters are reduced by ~8% and ~30% compared to
similar relations built with SDSS parameters. The tightest VRL relations are
obtained with the i-band radius, R235i, measured at 23.5 mag/arcsec^-2, and the
luminosity L235i, measured within R235i. Our VRL scaling relations compare
well, both in scatter and slope, with similar studies (such comparisons however
depend sensitively on the nature and size of the compared samples). The typical
slopes, b, and observed scatters, sigma, of the i-band VL, RL and RV relations
are bVL=0.27+/-0.01, bRL=0.41+/-0.01, bRV=1.52+/-0.07, and sigmaVL=0.074,
sigmaRL=0.071, sigmaRV=0.154 dex. Similar results for the SDSS g and r bands
are also provided. Smaller scatters may be achieved for more pruned samples. We
also compute scaling relations in terms of the baryonic mass (stars + gas),
Mbar, ranging from 10^8.7 Msol to 10^11.6 Msol. Our baryonic velocity-mass (VM)
relation has slope 0.29+/-0.01 and a measured scatter sigma_meas = 0.076 dex.
While the observed VL and VM relations have comparable scatter, the stellar and
baryonic VM relations may be intrinsically tighter, and thus potentially more
fundamental, than other VL relations of spiral galaxies.Comment: Submitted to MNRAS, comments welcom
The hierarchical build-up of the Tully-Fisher relation
We use the semi-analytic model GalICS to predict the Tully-Fisher relation in
the B, I and for the first time, in the K band, and its evolution with
redshift, up to z~1. We refined the determination of the disk galaxies rotation
velocity, with a dynamical recipe for the rotation curve, rather than a simple
conversion from the total mass to maximum velocity. The new recipe takes into
account the disk shape factor, and the angular momentum transfer occurring
during secular evolution leading to the formation of bulges. This produces
model rotation velocities that are lower by ~20-25% for the majority of the
spirals. We implemented stellar population models with a complete treatment of
the TP-AGB, which leads to a revision of the mass-to-light ratio in the
near-IR. I/K band luminosities increase by ~0.3/0.5 mags at redshift z=0 and by
~0.5/1 mags at z=3. With these two new recipes in place, the comparison between
the predicted Tully-Fisher relation with a series of datasets in the optical
and near-IR, at redshifts between 0 and 1, is used as a diagnostics of the
assembly and evolution of spiral galaxies in the model. At 0.4<z<1.2 the match
between the new model and data is remarkably good, especially for later-type
spirals (Sb/Sc). At z=0 the new model shows a net improvement in comparison
with its original version of 2003, and in accord with recent observations in
the K band, the model Tully-Fisher also shows a morphological differentiation.
However, in all bands the z=0 model Tully-Fisher is too bright. We argue that
this behaviour is caused by inadequate star formation histories in the model
galaxies at low redshifts. The star-formation rate declines too slowly, due to
continuous gas infall that is not efficiently suppressed. An analysis of the
model disk scale lengths, at odds with observations, hints to some missing
physics in the modeling of disk formation inside dark matter halos.Comment: Accepted for publication on MNRAS. 2 new plots, 1 new section, and
extended discussion. 21 pages, 11 figures in tota
E-Beam Patterned Gold Nanodot Arrays on Optical Fiber Tips for Localized Surface Plasmon Resonance Biochemical Sensing
Electron beam lithography (EBL) was used to directly pattern periodic gold nanodot arrays on optical fiber tips. Localized surface plasmon resonance of the E-beam patterned gold nanodot arrays on optical fiber tips was utilized for biochemical sensing. The advantage of the optical fiber based localized surface plasmon resonance (LSPR) sensors is the convenience to work with and work in harsh environments. An optical fiber tip LSPR refractive index sensor of 196 nm per refractive index unit (RIU) sensitivity has been demonstrated. The affinity sensing property of the fiber tip sensor was demonstrated using biotin/streptavidin as the receptor/analyte. The detection limit for streptavidin was determined to be 6 pM
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