1,606 research outputs found
Quality Assurance in Emergency Medicine - A Caribbean Perspective
Purpose
– Emergency medicine is a new specialty in the Caribbean. With the development of specialist training over the past 20 years, the issues of quality assurance and governance have become more prominent. The purpose of this paper is to explore the successes and challenges of implementing systems of quality assurance in this unique environment, highlighting issues peculiar to the Caribbean setting.
Design/methodology/approach
– This paper is a review of current practice in the emergency departments (ED) of the four major teaching hospitals of the University of the West Indies. Information was gathered through interviews with key stakeholders (including the respective ED residency directors, senior residents and senior nursing and administrative staff), review of departmental protocols and guidelines and reviews of current published and unpublished literature.
Findings
– Examples of good practice were identified in all six components of the clinical governance framework (clinical audit, clinical effectiveness, research and development, openness, risk management and education and training). Challenges to implementation of quality management included an underdeveloped quality culture, inadequate data collection, poor incentives for improvement and high external pressures, including staff shortages, departmental crowding and lack of public empowerment.
Originality/value
– This is the first published work on clinical governance and quality assurance in emergency medicine in the Caribbean. This paper gives an insight into the unique opportunities and challenges in the area of quality management and clinical governance in the developing world, and suggests ways forward with regard to more effective implementation of quality initiatives in under-resourced jurisdictions
Local Charge Excesses in Metallic Alloys: a Local Field Coherent Potential Approximation Theory
Electronic structure calculations performed on very large supercells have
shown that the local charge excesses in metallic alloys are related through
simple linear relations to the local electrostatic field resulting from
distribution of charges in the whole crystal.
By including local external fields in the single site Coherent Potential
Approximation theory, we develop a novel theoretical scheme in which the local
charge excesses for random alloys can be obtained as the responses to local
external fields. Our model maintains all the computational advantages of a
single site theory but allows for full charge relaxation at the impurity sites.
Through applications to CuPd and CuZn alloys, we find that, as a general rule,
non linear charge rearrangements occur at the impurity site as a consequence of
the complex phenomena related with the electronic screening of the external
potential. This nothwithstanding, we observe that linear relations hold between
charge excesses and external potentials, in quantitative agreement with the
mentioned supercell calculations, and well beyond the limits of linearity for
any other site property.Comment: 11 pages, 1 table, 7 figure
Medical applications based on nanotechnology
Poly-lactic-co-glycolic acid can form nanoparticles which can be applied in nanomedicine as delivery vehicle for therapeutic agents. Here the aim is to reduce negative side-effects and to obtain higher local concentrations at the site of action. This work is about determining the binding-capacity of PLGA nanoparticles to several substances, applying a small set of model proteins. Our aim was to find out, whether PLGA nanoparticles can transport drugs in order to make drug targeting in medicine easier. This would show us a new section of medicine with new ways of therapy methods
Screened Coulomb interactions in metallic alloys: I. Universal screening in the atomic sphere approximation
We have used the locally self-consistent Green's function (LSGF) method in
supercell calculations to establish the distribution of the net charges
assigned to the atomic spheres of the alloy components in metallic alloys with
different compositions and degrees of order. This allows us to determine the
Madelung potential energy of a random alloy in the single-site mean field
approximation which makes the conventional single-site density-functional-
theory coherent potential approximation (SS-DFT-CPA) method practically
identical to the supercell LSGF method with a single-site local interaction
zone that yields an exact solution of the DFT problem. We demonstrate that the
basic mechanism which governs the charge distribution is the screening of the
net charges of the alloy components that makes the direct Coulomb interactions
short-ranged. In the atomic sphere approximation, this screening appears to be
almost independent of the alloy composition, lattice spacing, and crystal
structure. A formalism which allows a consistent treatment of the screened
Coulomb interactions within the single-site mean-filed approximation is
outlined. We also derive the contribution of the screened Coulomb interactions
to the S2 formalism and the generalized perturbation method.Comment: 28 pages, 8 figure
How to superize Liouville equation
So far, there are described in the literature two ways to superize the
Liouville equation: for a scalar field (for ) and for a vector-valued
field (analogs of the Leznov--Saveliev equations) for N=1. Both superizations
are performed with the help of Neveu--Schwarz superalgebra. We consider another
version of these superLiouville equations based on the Ramond superalgebra,
their explicit solutions are given by Ivanov--Krivonos' scheme. Open problems
are offered
First-principles Calculation of the Formation Energy in MgO-CaO Solid Solutions
The electronic structure and total energy were calculated for ordered and
disordered MgO-CaO solid solutions within the multiple scattering theory in
real space and the local density approximation. Based on the dependence of the
total energy on the unit cell volume the equilibrium lattice parameter and
formation energy were determined for different solution compositions. The
formation energy of the solid solutions is found to be positive that is in
agreement with the experimental phase diagram, which shows a miscibility gap.Comment: 11 pages, 3 figure
Radiation induced oscillatory Hall effect in high mobility GaAs/AlGaAs devices
We examine the radiation induced modification of the Hall effect in high
mobility GaAs/AlGaAs devices that exhibit vanishing resistance under microwave
excitation. The modification in the Hall effect upon irradiation is
characterized by (a) a small reduction in the slope of the Hall resistance
curve with respect to the dark value, (b) a periodic reduction in the magnitude
of the Hall resistance, , that correlates with an increase in the
diagonal resistance, , and (c) a Hall resistance correction that
disappears as the diagonal resistance vanishes.Comment: 4 pages text, 4 color figure
An observation of spin-valve effects in a semiconductor field effect transistor: a novel spintronic device
We present the first spintronic semiconductor field effect transistor.
The injector and collector contacts of this device were made from magnetic
permalloy thin films with different coercive fields so that they could be
magnetized either parallel or antiparallel to each other in different applied
magnetic fields. The conducting medium was a two dimensional electron gas
(2DEG) formed in an AlSb/InAs quantum well.
Data from this device suggest that its resistance is controlled by two
different types of spin-valve effect: the first occurring at the
ferromagnet-2DEG interfaces; and the second occuring in direct propagation
between contacts.Comment: 4 pages, 2 figure
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