3,062 research outputs found
The Glasgow outcome at discharge scale: an inpatient assessment of disability after brain injury
This study assesses the validity and reliability of the Glasgow Outcome at Discharge Scale (GODS), which is a tool that is designed to assess disability after brain injury in an inpatient setting. It is derived from the Glasgow Outcome Scale-Extended (GOS-E), which assesses disability in the community after brain injury. Inter-rater reliability on the GODS is high (quadratic-weighted kappa 0.982; 95% confidence interval [CI] 0.968, 0.996) as is concurrent validity with the Disability Rating Scale (DRS) (Spearman correlation −0.728; 95% CI −0.819, −0.601). The GODS is significantly associated with physical and fatigue subscales of the short form (SF)-36 in hospital. In terms of predictive validity the GODS is highly associated with the GOS-E after discharge (Spearman correlation 0.512; 95% CI 0.281, 0.687), with the DRS, and with physical, fatigue, and social subscales of the SF-36. The GODS is recommended as an assessment tool for disability after brain injury pre-discharge and can be used in conjunction with the GOS-E to monitor disability between hospital and the community
Temperature variations of the disorder-induced vortex-lattice melting landscape
Differential magneto-optical imaging of the vortex-lattice melting process in
Bi_2Sr_2CaCu_2O_8 crystals reveals unexpected effects of quenched disorder on
the broadening of the first-order phase transition. The melting patterns show
that the disorder-induced melting landscape T_m(H,r) is not fixed, but rather
changes dramatically with varying field and temperature along the melting line.
The changes in both the scale and shape of the landscape are found to result
from the competing contributions of different types of quenched disorder which
have opposite effects on the local melting transition.Comment: 4 pages of text and 3 figures. Accepted for Publication in Physical
Review Letter
Dynamic Creation and Annihilation of Metastable Vortex Phase as a Source of Excess Noise
The large increase in voltage noise, commonly observed in the vicinity of the
peak-effect in superconductors, is ascribed to a novel noise mechanism. A
strongly pinned metastable disordered vortex phase, which is randomly generated
at the edges and annealed into ordered phase in the bulk, causes large
fluctuations in the integrated critical current of the sample. The excess noise
due to this dynamic admixture of two distinct phases is found to display
pronounced reentrant behavior. In the Corbino geometry the injection of the
metastable phase is prevented and, accordingly, the excess noise disappearsComment: 5 pages 3 figures. Accepted for publication in Europhysics letter
Models for the Observable System Parameters of Ultraluminous X-ray Sources
We investigate the evolution of the properties of model populations of
ultraluminous X-ray sources (ULXs) consisting of a black-hole accretor in a
binary with a donor star. We have computed models corresponding to three
different populations of black-hole binaries; two invoke stellar-mass (~10
Msun) black hole accretors, and the third utilizes intermediate-mass (~1000
Msun) black holes (IMBHs). For each of the three populations, we computed
30,000 binary evolution sequences using a full Henyey stellar evolution code.
The optical flux from the model ULXs includes contributions from the accretion
disk, due to x-ray irradiation as well as intrinsic viscous heating, and that
due to the donor star. We present "probability images" for the ULX systems in
planes of color-magnitude, orbital period vs. X-ray luminosity, and luminosity
vs. evolution time. Estimates of the numbers of ULXs in a typical galaxy as
functions of time and of X-ray luminosity are also presented. Our model CMDs
are compared with six ULX counterparts that have been discussed in the
literature. Overall, the observed systems seem more closely related to model
systems with very high-mass donors (> ~25 Msun) in binaries with IMBH
accretors. However, significant difficulties remain with both the IMBH and
stellar-mass black hole models.Comment: 15 pages, 8 figures, submitted to ApJ on Oct 05, 200
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