1,107 research outputs found
An Assessment of Clinical Wound Evaluation Scales
Objective : To compare 2 clinical wound scales and to determine a minimal clinically important difference (MCID) on the visual analog cosmesis scale. Methods : Using data from 2 previously published clinical trials, 91 lacerations and 43 surgical incisions were assessed on the 2 scales; a 100-mm visual analog scale (VAS) (0 = worst possible scar, 100 = best possible scar) and a wound evaluation scale (WES) assessing 6 clinical variables (a score of 6 is considered optimal, while a score of ≤5 suboptimal). All wound assessments on the VAS were done by 2 cosmetic surgeons who rated photographs on 2 occasions. A cohort of wounds on the WES were assessed by a second observer. The difference of the mean optimal and suboptimal VAS scores for each study was used to determine a MCID on the VAS scale. Results : The VAS scale yielded intraobserver agreements of 0.93 and 0.87 (95% CI: 0.89–0.96 and 0.78–0.93) and interobserver agreements of 0.50 and 0.71 (95% CI: 0.32–0.65 and 0.52–0.84) for lacerations and incisions, respectively. Kappa coefficient measuring agreement on the WES was 0.79 (95% CI: 0.57–1.0). The mean (±SD) VAS scores of optimal wounds were 72 ± 12 mm and 65 ± 20 mm, while the mean scores of suboptimal wounds were 57 ± 17 mm and 50 ± 23 mm for lacerations and incisions, respectively. Conclusions : An MCID on the VAS cosmesis scale is 15 mm. Studies should be designed to have a sample size and power to detect this difference.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75496/1/j.1553-2712.1998.tb02465.x.pd
MaGICC-WDM: the effects of warm dark matter in hydrodynamical simulations of disc galaxy formation
We study the effect of warm dark matter (WDM) on hydrodynamic simulations of
galaxy formation as part of the Making Galaxies in a Cosmological Context
(MaGICC) project. We simulate three different galaxies using three WDM
candidates of 1, 2 and 5 keV and compare results with pure cold dark matter
simulations. WDM slightly reduces star formation and produces less centrally
concentrated stellar profiles. These effects are most evident for the 1 keV
candidate but almost disappear for keV. All simulations
form similar stellar discs independent of WDM particle mass. In particular, the
disc scale length does not change when WDM is considered. The reduced amount of
star formation in the case of 1 keV particles is due to the effects of WDM on
merging satellites which are on average less concentrated and less gas rich.
The altered satellites cause a reduced starburst during mergers because they
trigger weaker disc instabilities in the main galaxy. Nevertheless we show that
disc galaxy evolution is much more sensitive to stellar feedback than it is to
WDM candidate mass. Overall we find that WDM, especially when restricted to
current observational constraints ( keV), has a minor
impact on disc galaxy formation.Comment: 13 pages, 9 figures, 2 tables; minor clarifications added in results
section, conclusions unchanged; accepted for publication in MNRA
Randomized Controlled Trial of Prophylactic Antibiotics for Dog Bites with Refined Cost Model
Reprints available through open access a
Reionization and the abundance of galactic satellites
One of the main challenges facing standard hierarchical structure formation
models is that the predicted abundance of galactic subhalos with circular
velocities of 10-30 km/s is an order of magnitude higher than the number of
satellites actually observed within the Local Group. Using a simple model for
the formation and evolution of dark halos, based on the extended
Press-Schechter formalism and tested against N-body results, we show that the
theoretical predictions can be reconciled with observations if gas accretion in
low-mass halos is suppressed after the epoch of reionization. In this picture,
the observed dwarf satellites correspond to the small fraction of halos that
accreted substantial amounts of gas before reionization. The photoionization
mechanism naturally explains why the discrepancy between predicted halos and
observed satellites sets in at about 30 km/s, and for reasonable choices of the
reionization redshift (z_re = 5-12) the model can reproduce both the amplitude
and shape of the observed velocity function of galactic satellites. If this
explanation is correct, then typical bright galaxy halos contain many low-mass
dark matter subhalos. These might be detectable through their gravitational
lensing effects, through their influence on stellar disks, or as dwarf
satellites with very high mass-to-light ratios. This model also predicts a
diffuse stellar component produced by large numbers of tidally disrupted
dwarfs, perhaps sufficient to account for most of the Milky Way's stellar halo.Comment: 5 pages, 2 figures, Submitted to Ap
Prospective, Randomized, Controlled Trial of Tissue Adhesive (2-Octylcyanoacrylate) vs Standard Wound Closure Techniques for Laceration Repair
Objective: To compare a new tissue adhesive, 2-octylcyanoacrylate, with standard wound closure techniques for the repair of traumatic lacerations. Methods: A prospective, randomized, controlled clinical trial enrolled consecutive patients >1 year of age with non-bite, non-crush-induced lacerations who presented 3 months) was assessed by physicians using a previously validated categorical cosmetic scale and by patients using a 100-mm visual analog scale. Results : There were 63 patients randomized to the octylcyanoacrylate group and 61 patients treated with standard wound closure techniques. The 2 treatment groups were similar with respect to age, gender, race, medical history, and wound characteristics. At the 5-to-10-day follow-up, only 1 wound was infected and only 2 wounds required reclosure due to dehiscence. These 3 patients received treatment with octylcyanoacrylate. At long-term follow-up, the cosmetic appearances were similar according to the patients (octylcyanoacrylate, 83.8 ± 19.4 mm vs standard techniques, 82.5 ± 17.6 mm; p = 0.72) and the physicians (optimal cosmetic appearance, 77% vs 80%; p = 0.67). Conclusions: Wounds treated with octylcyanoacrylate and standard wound closure techniques have similar cosmetic appearances 3 months later.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75580/1/j.1553-2712.1998.tb02590.x.pd
The Formation of Polar Disk Galaxies
Polar Ring Galaxies, such as NGC4650A, are a class of galaxy which have two
kinematically distinct components that are inclined by almost 90 degrees to
each other. These striking galaxies challenge our understanding of how galaxies
form; the origin of their distinct components has remained uncertain, and the
subject of much debate. We use high-resolution cosmological simulations of
galaxy formation to show that Polar Ring Galaxies are simply an extreme example
of the angular moment misalignment that occurs during the hierarchical
structure formation characteristic of Cold Dark Matter cosmology. In our model,
Polar Ring Galaxies form through the continuous accretion of gas whose angular
momentum is misaligned with the central galaxy.Comment: Submitted to ApJ. 8 pages in emulate ApJ style. 2 associated
animations are found at: http://www.youtube.com/watch?v=c-H3WzaewdY
http://www.youtube.com/watch?v=9Xf3fJkgWE
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Reversal of a single base pair step controls guanine photo-oxidation by an intercalating Ru(II) dipyridophenazine complex
Small changes in DNA sequence can often have major biological effects. Here the rates and yields of guanine photo-oxidation by Λ [Ru(TAP)2(dppz)]2+ have been compared in 5′-{CCGGATCCGG}2 and 5′-{CCGGTACCGG}2 using ps/ns transient visible and time-resolved IR (TRIR) spectroscopy. The inefficiency of electron transfer in the TA sequence is consistent with the 5′-TA-3′ vs. 5′-AT-3′ binding preference predicted by X-ray crystallography. The TRIR spectra also reveal the differences in binding sites in the two oligonucleotides
The Metamorphosis of Tidally Stirred Dwarf Galaxies
We present results from high-resolution N-Body/SPH simulations of
rotationally supported dwarf irregular galaxies moving on bound orbits in the
massive dark matter halo of the Milky Way.The dwarf models span a range in disk
surface density and the masses and sizes of their dark halos are consistent
with the predictions of cold dark matter cosmogonies. We show that the strong
tidal field of the Milky Way determines severe mass loss in their halos and
disks and induces bar and bending instabilities that transform low surface
brightness dwarfs (LSBs) into dwarf spheroidals (dSphs) and high surface
brightness dwarfs (HSBs) into dwarf ellipticals (dEs) in less than 10 Gyr. The
final central velocity dispersions of the remnants are in the range 8-30 km/s
and their final falls to values , matching well the
kinematics of early-type dwarfs. The transformation requires the orbital time
of the dwarf to be \simlt 3-4 Gyr, which implies a halo as massive and
extended as predicted by hierarchical models of galaxy formation to explain the
origin of even the farthest dSph satellites of the Milky Way, Leo I and Leo II.
Only dwarfs with central dark matter densities as high as those of Draco and
Ursa Minor can survive for 10 Gyr in the proximity of the Milky Way: this is
naturally achieved within hierarchical models, where the densest objects should
have small orbital times due to their early formation epochs. Part of the gas
is stripped and part is funneled to the center due to the bar, generating one
strong burst of star formation in HSBs and smaller, multiple bursts in LSBs.
Extended low-surface brightness stellar and gaseous streams originate from LSBs
and, when projected along the line of sight, can lead to overestimate the
mass-to-light ratio of the bound remnant by a factor \simlt 2,Comment: 29 pages, 34 figures, submitted to ApJ. Figures 5,11 and 32 are given
as separate GIF files. Other figures and the movies of the simulations can be
found at http://pcblu.mib.infn.it/~lucio/LG/LG.htm
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