525 research outputs found
The Care Homes Use of Medicines Study: prevalence, causes and potential harm of medication errors in care homes for older people
Introduction: Care home residents are at particular risk from medication errors, and our objective was to determine the prevalence and potential harm of prescribing, monitoring, dispensing and administration errors in UK care homes, and to identify their causes.
Methods: A prospective study of a random sample of residents within a purposive sample of homes in three areas. Errors were identified by patient interview, note review, observation of practice and examination of dispensed items. Causes were understood by observation and from theoretically framed interviews with home staff, doctors and pharmacists. Potential harm from errors was assessed by expert judgement.
Results: The 256 residents recruited in 55 homes were taking a mean of 8.0 medicines. One hundred and seventy-eight (69.5%) of residents had one or more errors. The mean number per resident was 1.9 errors. The mean potential harm from prescribing, monitoring, administration and dispensing errors was 2.6, 3.7, 2.1 and 2.0 (0â=âno harm, 10â=âdeath), respectively. Contributing factors from the 89 interviews included doctors who were not accessible, did not know the residents and lacked information in homes when prescribing; home staffâs high workload, lack of medicines training and drug round interruptions; lack of team work among home, practice and pharmacy; inefficient ordering systems; inaccurate medicine records and prevalence of verbal communication; and difficult to fill (and check) medication administration systems.
Conclusions: That two thirds of residents were exposed to one or more medication errors is of concern. The will to improve exists, but there is a lack of overall responsibility. Action is required from all concerned
PI3 kinase and FOXO1 transcription factor activity differentially control B cells in the germinal center light and dark zones
Phosphatidylinositol 3' OH kinase (PI3K) signaling and FOXO transcription factors play opposing roles at several B cell developmental stages. We show here abundant nuclear FOXO1 expression in the proliferative compartment of the germinal center (GC), its dark zone (DZ), and PI3K activity, downregulating FOXO1, in the light zone (LZ), where cells are selected for further differentiation. In the LZ, however, FOXO1 was expressed in a fraction of cells destined for DZ reentry. Upon FOXO1 ablation or induction of PI3K activity, GCs lost their DZ, owing at least partly to downregulation of the chemokine receptor CXCR4. Although this prevented proper cyclic selection of cells in GCs, somatic hypermutation and proliferation were maintained. Class switch recombination was partly lost due to a failure of switch region targeting by activation-induced deaminase (AID)
Observation of the decay \psip\rar\kstark
Using 14 million events collected with the BESII detector,
branching fractions of \psip\rar\kstarkpm and \kstarknn are determined to
be: \calB(\psip\rar\kstarkpm)=(2.9^{+1.3}_{-1.7}\pm0.4)\times 10^{-5} and
\calB(\psip\rar\kstarknn)=(13.3^{+2.4}_{-2.7}\pm1.9)\times 10^{-5}. The
results confirm the violation of the "12%" rule for these two decay channels
with higher precision. A large isospin violation between the charged and
neutral modes is observed.Comment: 5 pages, 3 figure
Plasma Wakefield Acceleration with a Modulated Proton Bunch
The plasma wakefield amplitudes which could be achieved via the modulation of
a long proton bunch are investigated. We find that in the limit of long bunches
compared to the plasma wavelength, the strength of the accelerating fields is
directly proportional to the number of particles in the drive bunch and
inversely proportional to the square of the transverse bunch size. The scaling
laws were tested and verified in detailed simulations using parameters of
existing proton accelerators, and large electric fields were achieved, reaching
1 GV/m for LHC bunches. Energy gains for test electrons beyond 6 TeV were found
in this case.Comment: 9 pages, 7 figure
All-optical switching and strong coupling using tunable whispering-gallery-mode microresonators
We review our recent work on tunable, ultrahigh quality factor
whispering-gallery-mode bottle microresonators and highlight their applications
in nonlinear optics and in quantum optics experiments. Our resonators combine
ultra-high quality factors of up to Q = 3.6 \times 10^8, a small mode volume,
and near-lossless fiber coupling, with a simple and customizable mode structure
enabling full tunability. We study, theoretically and experimentally, nonlinear
all-optical switching via the Kerr effect when the resonator is operated in an
add-drop configuration. This allows us to optically route a single-wavelength
cw optical signal between two fiber ports with high efficiency. Finally, we
report on progress towards strong coupling of single rubidium atoms to an
ultra-high Q mode of an actively stabilized bottle microresonator.Comment: 20 pages, 24 figures. Accepted for publication in Applied Physics B.
Changes according to referee suggestions: minor corrections to some figures
and captions, clarification of some points in the text, added references,
added new paragraph with results on atom-resonator interactio
Wind modelling of very massive stars up to 300 solar masses
Some studies have claimed a universal stellar upper-mass limit of 150 Msun. A
factor that is often overlooked is that there might be a difference between the
current and initial masses of the most massive stars, as a result of mass loss.
We present Monte Carlo mass-loss predictions for very massive stars in the
range 40-300 Msun, with large luminosities and Eddington factors Gamma. Using
our new dynamical approach, we find an upturn in the mass-loss vs. Gamma
dependence, at the point where the winds become optically thick. This coincides
with the location where wind efficiency numbers surpass the single-scattering
limit of Eta = 1, reaching values up to Eta = 2.5. Our modelling suggests a
transition from common O-type winds to Wolf-Rayet characteristics at the point
where the winds become optically thick. This transitional behaviour is also
revealed with respect to the wind acceleration parameter beta, which starts at
values below 1 for the optically thin O-stars, and naturally reaches values as
high as 1.5-2 for the optically thick Wolf-Rayet models. An additional finding
concerns the transition in spectral morphology of the Of and WN characteristic
He II line at 4686 Angstrom. When we express our mass-loss predictions as a
function of the electron scattering Gamma_e (=L/M) only, we obtain a mass-loss
Gamma dependence that is consistent with a previously reported power-law Mdot
propto Gamma^5 (Vink 2006) that was based on our semi-empirical modelling
approach. When we express Mdot in terms of both Gamma and stellar mass, we find
Mdot propto M^0.8 Gamma^4.8 for our high Gamma models. Finally, we confirm that
the Gamma-effect on the mass-loss predictions is much stronger than that of an
increased helium abundance, calling for a fundamental revision in the way mass
loss is incorporated in evolutionary models of the most massive stars.Comment: minor language changes (Astronomy & Astrophysics in press - 11 pages,
10 figures
Optimal measurements for simultaneous quantum estimation of multiple phases
A quantum theory of multiphase estimation is crucial for quantum-enhanced
sensing and imaging and may link quantum metrology to more complex quantum
computation and communication protocols. In this letter we tackle one of the
key difficulties of multiphase estimation: obtaining a measurement which
saturates the fundamental sensitivity bounds. We derive necessary and
sufficient conditions for projective measurements acting on pure states to
saturate the maximal theoretical bound on precision given by the quantum Fisher
information matrix. We apply our theory to the specific example of
interferometric phase estimation using photon number measurements, a convenient
choice in the laboratory. Our results thus introduce concepts and methods
relevant to the future theoretical and experimental development of
multiparameter estimation.Comment: 4 pages + appendix, 2 figure
Non-identical particle correlations in 130 and 200 AGeV collisions at STAR
STAR has performed a correlation analyses of pion-kaon and pion-proton pairs
for sqrt(s_NN)=130 AGeV and sqrt(s_NN)=200 AGeV and kaon-proton, proton-Lambda
and pion-Cascade pairs for AuAu collisions sqrt(s_NN)=200 AGeV. They show that
average emission space-time points of pions, kaons and protons are not the
same. These asymmetries are interpreted as a consequence of transverse radial
expansion of the system; emission time differences explain only part of the
asymmetry. Therefore our measurements independently confirm the existence of
transverse radial flow. Furthermore, correlations of strange hyperons is
investigated by performing proton-Lambda and pion-Cascade analyses, giving
estimates of source size at high m_{T}. The strong interaction potential
between (anti-)proton and lambda as well as kaon and proton is investigated.Comment: 5 pages, 3 figures, Quark Matter 04 proceedings, submitted to J.
Phys. G: Nucl. Phy
Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS
We present the results of a search for new, heavy particles that decay at a
significant distance from their production point into a final state containing
charged hadrons in association with a high-momentum muon. The search is
conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV
and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS
detector operating at the Large Hadron Collider. Production of such particles
is expected in various scenarios of physics beyond the standard model. We
observe no signal and place limits on the production cross-section of
supersymmetric particles in an R-parity-violating scenario as a function of the
neutralino lifetime. Limits are presented for different squark and neutralino
masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final
version to appear in Physics Letters
Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment
This paper describes an analysis of the angular distribution of W->enu and
W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with
the ATLAS detector at the LHC in 2010, corresponding to an integrated
luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and
the missing transverse energy, the W decay angular distribution projected onto
the transverse plane is obtained and analysed in terms of helicity fractions
f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV
and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw
> 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour,
are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017
+/- 0.030, where the first uncertainties are statistical, and the second
include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables,
revised author list, matches European Journal of Physics C versio
- âŠ