1,625 research outputs found
A methodology for setting practice criteria in healthcare
Practice criteria are an important part of health care and have taken a new prominence in the trend to address quality-of-care issues. Once an organisation makes a commitment to addressing its quality-of- care, it must define 'quality' in operational terms. Practice criteria do just that. The organisation ensures consistent, high-quality services through the correct application of practice criteria. This paper outlines a methodology that has been used in at least three countries to date. Early indications are that it is useful for helping an organisation begin its quality improvement 'journey'.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
Systematic thermal reduction of neutronization in core-collapse supernovae
We investigate to what extent the temperature dependence of the nuclear
symmetry energy can affect the neutronization of the stellar core prior to
neutrino trapping during gravitational collapse. To this end, we implement a
one-zone simulation to follow the collapse until beta equilibrium is reached
and the lepton fraction remains constant. Since the strength of electron
capture on the neutron-rich nuclei associated to the supernova scenario is
still an open issue, we keep it as a free parameter. We find that the
temperature dependence of the symmetry energy consistently yields a small
reduction of deleptonization, which corresponds to a systematic effect on the
shock wave energetics: the gain in dissociation energy of the shock has a small
yet non-negligible value of about 0.4 foe (1 foe = 10^51 erg) and this result
is almost independent from the strength of nuclear electron capture. The
presence of such a systematic effect and its robustness under changes of the
parameters of the one-zone model are significative enough to justify further
investigations with detailed numerical simulations of supernova explosions.Comment: 15 pages, 2 tables, 3 figure
Minimum EMG burst duration in healthy controls : implications for electrodiagnosis in movement disorders
Background
EMG burst duration can provide additional diagnostic information when investigating hyperkinetic movement disorders, particularly when a functional movement disorder is suspected. It is generally accepted that EMG bursts <50ms are pathological.
Objective
To reâassess minimum physiological EMG burst duration.
Methods
Surface EMG was recorded from face, trunk and limb muscles in controls (n=60; age 19â85). Subjects were instructed to generate the briefest possible ballistic movements involving each muscle (40 repetitions) or, in muscles spanning joints, to generate rapid rhythmic alternating movements (20â30s), or both.
Results
We found no effect of age on EMG burst duration. However, EMG burst duration varied significantly between body regions. Rhythmic EMG bursts were shorter than ballistic bursts but only significantly so for lower limbs (p<0.001). EMG bursts of duration <50ms were frequently observed, particularly in appendicular muscles.
Conclusion
We present normal reference data for minimum EMG burst duration, which may assist clinical interpretation when investigating hyperkinetic movement disorders
Magnetic dipole probes of the sd and pf shell crossing in the A=36,38 argon isotopes
We have calculated the M1 strength distributions in the A=36,38 argon
isotopes within large-scale shell model studies which consider valence nucleons
in the sd and pf shells. While the M1 strength in 36Ar is well reproduced
within the sd shell, the experimentally observed strong fragmentation of the M1
strength in 38Ar requires configuration mixing between the sd and the pf shells
adding to our understanding of correlations across the N=20 shell gap.Comment: 14 pages, 8 figure
Peculiarities of the stochastic motion in antiferromagnetic nanoparticles
Antiferromagnetic (AFM) materials are widely used in spintronic devices as
passive elements (for stabilization of ferromangetic layers) and as active
elements (for information coding). In both cases switching between the
different AFM states depends in a great extent from the environmental noise. In
the present paper we derive the stochastic Langevin equations for an AFM vector
and corresponding Fokker-Planck equation for distribution function in the phase
space of generalised coordinate and momentum. Thermal noise is modeled by a
random delta-correlated magnetic field that interacts with the dynamic
magnetisation of AFM particle. We analyse in details a particular case of the
collinear compensated AFM in the presence of spin-polarised current. The energy
distribution function for normal modes in the vicinity of two equilibrium
states (static and stationary) in sub- and super-critical regimes is found. It
is shown that the noise-induced dynamics of AFM vector has pecuilarities
compared to that of magnetisation vector in ferromagnets.Comment: Submitted to EPJ ST, presented at the 4-th Conference on Statistical
Physics, Lviv, Ukraine, 201
Propagator of a Charged Particle with a Spin in Uniform Magnetic and Perpendicular Electric Fields
We construct an explicit solution of the Cauchy initial value problem for the
time-dependent Schroedinger equation for a charged particle with a spin moving
in a uniform magnetic field and a perpendicular electric field varying with
time. The corresponding Green function (propagator) is given in terms of
elementary functions and certain integrals of the fields with a characteristic
function, which should be found as an analytic or numerical solution of the
equation of motion for the classical oscillator with a time-dependent
frequency. We discuss a particular solution of a related nonlinear Schroedinger
equation and some special and limiting cases are outlined.Comment: 17 pages, no figure
The Hyperfine Spin Splittings In Heavy Quarkonia
The hyperfine spin splittings in heavy quarkonia are studied using the
recently developed renormalization group improved spin-spin potential which is
independent of the scale parameter . The calculated energy difference
between the and the fits the experimental data well, while
the predicted energy difference between the center of the gravity
of states and the state of charmonium has the correct
sign but is somewhat larger than the experimental data. This is not surprising
since there are several other contributions to , which we discuss,
that are of comparable size ( MeV) that should be included, before
precise agreement with the data can be expected. The mass differences of the
, , , and
are also predicted.Comment: 17 page
Interleukin-7 deficiency in rheumatoid arthritis: consequences for therapy-induced lymphopenia
We previously demonstrated prolonged, profound CD4+ T-lymphopenia in rheumatoid arthritis (RA) patients following lymphocyte-depleting therapy. Poor reconstitution could result either from reduced de novo T-cell production through the thymus or from poor peripheral expansion of residual T-cells. Interleukin-7 (IL-7) is known to stimulate the thymus to produce new T-cells and to allow circulating mature T-cells to expand, thereby playing a critical role in T-cell homeostasis. In the present study we demonstrated reduced levels of circulating IL-7 in a cross-section of RA patients. IL-7 production by bone marrow stromal cell cultures was also compromised in RA. To investigate whether such an IL-7 deficiency could account for the prolonged lymphopenia observed in RA following therapeutic lymphodepletion, we compared RA patients and patients with solid cancers treated with high-dose chemotherapy and autologous progenitor cell rescue. Chemotherapy rendered all patients similarly lymphopenic, but this was sustained in RA patients at 12 months, as compared with the reconstitution that occurred in cancer patients by 3â4 months. Both cohorts produced naĂŻve T-cells containing T-cell receptor excision circles. The main distinguishing feature between the groups was a failure to expand peripheral T-cells in RA, particularly memory cells during the first 3 months after treatment. Most importantly, there was no increase in serum IL-7 levels in RA, as compared with a fourfold rise in non-RA control individuals at the time of lymphopenia. Our data therefore suggest that RA patients are relatively IL-7 deficient and that this deficiency is likely to be an important contributing factor to poor early T-cell reconstitution in RA following therapeutic lymphodepletion. Furthermore, in RA patients with stable, well controlled disease, IL-7 levels were positively correlated with the T-cell receptor excision circle content of CD4+ T-cells, demonstrating a direct effect of IL-7 on thymic activity in this cohort
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