22,058 research outputs found
Establishing the potential for using routine data on Incapacity Benefit to assess the local impact of policy initiatives
<i>Background</i>: Incapacity Benefit (IB) is the key contributory benefit for people who are incapable of work because of illness or disability.
<i>Methods</i>: The aims were to establish the utility of routinely collected data for local evaluation and to provide a descriptive epidemiology of the IB population in Glasgow and Scotland for the period 2000ā05 using data supplied by the Department for Work and Pensions.
<i>Results</i>: Glasgow's IB population is large in absolute and relative terms but is now falling, mainly due to a decrease in on flow. Claimants, tend to be older, have a poor work history and suffer from mental health problems. The rate of decline has been greater in Glasgow than Scotland, although the rate of on flow is still higher.
<i>Conclusions</i>: Department for Work and Pensions (DWP) data can be used locally to provide important insights into the dynamics of the IB population. However, to be truly useful, more work needs to be undertaken to combine the DWP data with other information
Comparison of methods for estimating continuous distributions of relaxation times
The nonparametric estimation of the distribution of relaxation times approach
is not as frequently used in the analysis of dispersed response of dielectric
or conductive materials as are other immittance data analysis methods based on
parametric curve fitting techniques. Nevertheless, such distributions can yield
important information about the physical processes present in measured
material. In this letter, we apply two quite different numerical inversion
methods to estimate the distribution of relaxation times for glassy \lila\
dielectric frequency-response data at 225 \kelvin. Both methods yield unique
distributions that agree very closely with the actual exact one accurately
calculated from the corrected bulk-dispersion Kohlrausch model established
independently by means of parametric data fit using the corrected modulus
formalism method. The obtained distributions are also greatly superior to those
estimated using approximate functions equations given in the literature.Comment: 4 pages and 4 figure
Ion observations from geosynchronous orbit as a proxy for ion cyclotron wave growth during storm times
[1] There is still much to be understood about the processes contributing to relativistic electron enhancements and losses in the radiation belts. Wave particle interactions with both whistler and electromagnetic ion cyclotron (EMIC) waves may precipitate or accelerate these electrons. This study examines the relation between EMIC waves and resulting relativistic electron flux levels after geomagnetic storms. A proxy for enhanced EMIC waves is developed using Los Alamos National Laboratory Magnetospheric Plasma Analyzer plasma data from geosynchronous orbit in conjunction with linear theory. In a statistical study using superposed epoch analysis, it is found that for storms resulting in net relativistic electron losses, there is a greater occurrence of enhanced EMIC waves. This is consistent with the hypothesis that EMIC waves are a primary mechanism for the scattering of relativistic electrons and thus cause losses of such particles from the magnetosphere
Chiral boundary conditions for Quantum Hall systems
A quantum mesoscopic billiard can be viewed as a bounded electronic system
due to some external confining potential. Since, in general, we do not have
access to the exact expression of this potential, it is usually replaced by a
set of boundary conditions. We discuss, in addition to the standard Dirichlet
choice, the other possibilities of boundary conditions which might correspond
to more complicated physical situations including the effects of many body
interactions or of a strong magnetic field. The latter case is examined more in
details using a new kind of chiral boundary conditions for which it is shown
that in the Quantum Hall regime, bulk and edge characteristics can be described
in a unified way.Comment: 16 pages, LaTeX, 2 figures, to be published in the Proceedings of the
Minerva workshop on Mesoscopics, Fractals and Neural Networks, Phil. Mag.
(1997
Viral proteins expressed in the protozoan parasite Eimeria tenella are detected by the chicken immune system
BACKGROUND: Eimeria species are parasitic protozoa that cause coccidiosis, an intestinal disease commonly characterised by malabsorption, diarrhoea and haemorrhage that is particularly important in chickens. Vaccination against chicken coccidiosis is effective using wild-type or attenuated live parasite lines. The development of protocols to express foreign proteins in Eimeria species has opened up the possibility of using Eimeria live vaccines to deliver heterologous antigens and function as multivalent vaccine vectors that could protect chickens against a range of pathogens. RESULTS: In this study, genetic complementation was used to express immunoprotective virus antigens in Eimeria tenella. Infectious bursal disease virus (IBDV) causes Gumboro, an immunosuppressive disease that affects productivity and can interfere with the efficacy of poultry vaccination programmes. Infectious laryngotracheitis virus (ILTV) causes a highly transmissible respiratory disease for which strong cellular immunity and antibody responses are required for effective vaccination. Genes encoding the VP2 protein from a very virulent strain of IBDV (vvVP2) and glycoprotein I from ILTV (gI) were cloned downstream of 5āEt-Actin or 5āEt-TIF promoter regions in plasmids that also contained a mCitrine fluorescent reporter cassette under control of the 5āEt-MIC1 promoter. The plasmids were introduced by nucleofection into E. tenella sporozoites, which were then used to infect chickens. Progeny oocysts were sorted by FACS and passaged several times in vivo until the proportion of fluorescent parasites in each transgenic population reached ~20Ā % and the number of transgene copies per parasite genome decreased to <Ā 10. All populations were found to transcribe and express the transgene and induced the generation of low titre, transgene-specific antibodies when used to immunise chickens. CONCLUSIONS: E. tenella can express antigens of other poultry pathogens that are successfully recognised by the chicken immune system. Nonetheless, further work has to be done in order to improve the levels of expression for its future use as a multivalent vaccine vector. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13071-016-1756-2) contains supplementary material, which is available to authorized users
Tuning the effects of Landau-level mixing on anisotropic transport in quantum Hall systems
Electron-electron interactions in half-filled high Landau levels in
two-dimensional electron gases in a strong perpendicular magnetic field can
lead to states with anisotropic longitudinal resistance. This longitudinal
resitance is generally believed to arise from broken rotational invariance,
which is indicated by charge density wave (CDW) order in Hartree-Fock
calculations. We use the Hartree-Fock approximation to study the influence of
externally tuned Landau level mixing on the formation of interaction induced
states that break rotational invariance in two-dimensional electron and hole
systems. We focus on the situation when there are two non-interacting states in
the vicinity of the Fermi level and construct a Landau theory to study coupled
charge density wave order that can occur as interactions are tuned and the
filling or mixing are varied. We examine in detail a specific example where
mixing is tuned externally through Rashba spin-orbit coupling. We calculate the
phase diagram and find the possibility of ordering involving coupled striped or
triangular charge density waves in the two levels. Our results may be relevant
to recent transport experiments on quantum Hall nematics in which Landau-level
mixing plays an important role.Comment: 25 pages, 6 figure
Nanoscale Torsional Optomechanics
Optomechanical transduction is demonstrated for nanoscale torsional
resonators evanescently coupled to optical microdisk whispering gallery mode
resonators. The on-chip, integrated devices are measured using a fully
fiber-based system, including a tapered and dimpled optical fiber probe. With a
thermomechanically calibrated optomechanical noise floor down to 7 fm/sqrt(Hz),
these devices open the door for a wide range of physical measurements involving
extremely small torques, as little as 4x10^-20 N*m.Comment: 4 pages, 4 figures - Accepted to APL Oct 22nd, 2012. To appear in
February 4th issue - as cover articl
Coordinate shift in the semiclassical Boltzmann equation and the anomalous Hall effect
We propose a gauge invariant expression for the side jump associated with
scattering between particular Bloch states. Our expression for the side jump
follows from the Born series expansion for the scattering T-matrix in powers of
the strength of the scattering potential. Given our gauge invariant side jump
expression, it is possible to construct a semiclassical Boltzmann theory of the
anomalous Hall effect which expresses all previously identified contributions
in terms of gauge invariant quantities and does not refer explicitly to
off-diagonal terms in the density-matrix response.Comment: 6 pages, 1 fugure. submitted to PR
Chern-Simons matrix models and Stieltjes-Wigert polynomials
Employing the random matrix formulation of Chern-Simons theory on Seifert
manifolds, we show how the Stieltjes-Wigert orthogonal polynomials are useful
in exact computations in Chern-Simons matrix models. We construct a
biorthogonal extension of the Stieltjes-Wigert polynomials, not available in
the literature, necessary to study Chern-Simons matrix models when the geometry
is a lens space. We also discuss several other results based on the properties
of the polynomials: the equivalence between the Stieltjes-Wigert matrix model
and the discrete model that appears in q-2D Yang-Mills and the relationship
with Rogers-Szego polynomials and the corresponding equivalence with an unitary
matrix model. Finally, we also give a detailed proof of a result that relates
quantum dimensions with averages of Schur polynomials in the Stieltjes-Wigert
ensemble.Comment: 25 pages, AMS-LaTe
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