9,133 research outputs found
The relation of body mass index, demographic and health-related variables to length of stay for patients at an acute rehabilitation hospital after total hip arthroplasty
Obesity is a growing public health concern world-wide. At the same time, knee and hip replacements are becoming an increasingly regular treatment for osteoarthritis. There are conflicting reports in the literature as to what extent body mass affects the length of stay (LOS) of patients undergoing total hip replacements. This chart review aims at examining the Ârelationship between body mass index (BMI), demographic and health-related variables, and LOS. The retrospective chart review of one acute inpatient rehabilitation facility involved n = 119 patients. There was no significant association between LOS and body mass index (BMI), confirming earlier results. Insurance payer type (Medicare vs private) was statistically significant related to LOS. Moreover, there was a trend for the potential influence of race/ethnic patient background on LOS with Caucasians having shorter hospital stays. © 2010 Greenberg and Kroll, publisher and licensee Dove Medical Press Ltd. This is an Open Access article which permits unrestricted noncommercial use, provided the original work is properly cited.</p
Mixing of pseudoscalar mesons and isospin symmetry breaking
Mixing of the pseudoscalar mesons is discussed in the quark-flavor basis with
the hypothesis that the basis decay constants follow the pattern of particle
state mixing. The divergences of the axial vector currents which embody the
axial vector anomaly, combined with this hypothesis provide a calculational
scheme for the parameters describing the mixing of the pion, eta and eta'
mesons. Phenomenological applications of this mixing scheme are presented with
particular interest focussed on isospin symmetry breaking in QCD estimated as
eta and eta' admixtures to the pion. In contrast to previous work a possible
difference in the basis decay constants f_u and f_d is considered and
consequences of this potentially large effect on the strength of isospin
symmetry breaking is discussed.Comment: 10 pages, (using LATEX with w-ijmpa.sty), invited talk presented at
MESON 2004, 8th Intern. Workshop on Meson Production, Properties and
Interaction
Mixing and Decay Constants of Pseudoscalar Mesons: The Sequel
We present further tests and applications of the new eta-eta' mixing scheme
recently proposed by us. The particle states are decomposed into orthonormal
basis vectors in a light-cone Fock representation. Because of flavor symmetry
breaking the mixing of the decay constants can be identical to the mixing of
particle states at most for a specific choice of this basis. Theoretical and
phenomenological considerations show that the quark flavor basis has this
property and allows, therefore, for a reduction of the number of mixing
parameters. A detailed comparison with other mixing schemes is also presented.Comment: 9 page
Perturbative and non-perturbative QCD corrections to wide-angle Compton scattering
We investigate corrections to the handbag approach for wide-angle Compton
scattering off protons at moderately large momentum transfer: the photon-parton
subprocess is calculated to next-to-leading order QCD and contributions from
the generalized parton distribution E} are taken into account. Photon and
proton helicity flip amplitudes are non-zero due to these corrections which
leads to a wealth of polarization phenomena in Compton scattering. Thus, for
instance, the incoming photon asymmetry or the transverse polarization of the
proton are non-zero although small.Comment: 19 pages, 9 figures (using LATEX with epsfig
Patient-reported outcome measures for chronic obstructive pulmonary disease: the exclusion of people with low literacy skills and learning disabilities
<p>Background: Patient-reported outcome measures (PROMs)
are intended to reïŹect outcomes relevant to patients. They are
increasingly used for healthcare quality improvement. To
produce valid measures, patients should be involved in the
development process but it is unclear whether this usually
includes people with low literacy skills or learning disabilities.
This potential exclusion raises concerns about whether these
groups will be able to use these measures and participate in
quality improvement practices.</p>
<p>Methods: Taking PROMs for chronic obstructive pulmonary disease (COPD) as an exemplar condition, our review
determined the inclusion of people with low literacy skills and
learning disabilities in research developing, validating, and
using 12 PROMs for COPD patients. The studies included in
our review were based on those identiïŹed in two existing
systematic reviews and our update of this search.
Results People with low literacy skills and/or learning
disabilities were excluded from the development of
PROMs in two ways: explicitly through the participant
eligibility criteria and, more commonly, implicitly through
recruitment or administration methods that would require
high-level reading and cognitive abilities. None of the
studies mentioned efforts to include people with low literacy skills or learning disabilities.</p>
<p>Conclusion: Our ïŹndings suggest that people with low
literacy skills or learning disabilities are left out of the
development of PROMs. Given that implicit exclusion was
most common, researchers and those who administer
PROMs may not even be aware of this problem. Without
effort to improve inclusion, unequal quality improvement
practices may become embedded in the health system.</p>
Linear model for fast background subtraction in oligonucleotide microarrays
One important preprocessing step in the analysis of microarray data is
background subtraction. In high-density oligonucleotide arrays this is
recognized as a crucial step for the global performance of the data analysis
from raw intensities to expression values.
We propose here an algorithm for background estimation based on a model in
which the cost function is quadratic in a set of fitting parameters such that
minimization can be performed through linear algebra. The model incorporates
two effects: 1) Correlated intensities between neighboring features in the chip
and 2) sequence-dependent affinities for non-specific hybridization fitted by
an extended nearest-neighbor model.
The algorithm has been tested on 360 GeneChips from publicly available data
of recent expression experiments. The algorithm is fast and accurate. Strong
correlations between the fitted values for different experiments as well as
between the free-energy parameters and their counterparts in aqueous solution
indicate that the model captures a significant part of the underlying physical
chemistry.Comment: 21 pages, 5 figure
Ising magnets with mobile defects
Motivated by recent experiments on cuprates with low-dimensional magnetic
interactions, a new class of two-dimensional Ising models with short-range
interactions and mobile defects is introduced and studied. The non-magnetic
defects form lines, which, as temperature increases, first meander and then
become unstable. Using Monte Carlo simulations and analytical low- and
high-temperature considerations, the instability of the defect stripes is
monitored for various microscopic and thermodynamic quantities in detail for a
minimal model, assuming some of the couplings to be indefinitely strong. The
robustness of the findings against weakening the interactions is discussed as
well
Resummed Green-Kubo relations for a fluctuating fluid-particle model
A recently introduced stochastic model for fluid flow can be made Galilean
invariant by introducing a random shift of the computational grid before
collisions. This grid shifting procedure accelerates momentum transfer between
cells and leads to a collisional contribution to transport coefficients. By
resumming the Green-Kubo relations derived in a previous paper, it is shown
that this collisional contribution to the transport coefficients can be
determined exactly. The resummed Green-Kubo relations also show that there are
no mixed kinetic-collisional contributions to the transport coefficients. The
leading correlation corrections to the transport coefficients are discussed,
and explicit expressions for the transport coefficients are presented and
compared with simulation data.Comment: 4 pages including 4 figures, submitted to PRE Rapid Com
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