1,256 research outputs found
Cost effectiveness of community leg ulcer clinics: randomised controlled trial
Objectives: To establish the relative cost effectiveness of community leg ulcer clinics that use four layer
compression bandaging versus usual care provided by district nurses.
Design: Randomised controlled trial with 1 year of follow up.
Setting: Eight community based research clinics in four trusts in Trent.
Subjects: 233 patients with venous leg ulcers allocated at random to intervention (120) or control (113) group.
Interventions: Weekly treatment with four layer bandaging in a leg ulcer clinic (clinic group) or usual care at home by the district nursing service (control group).
Main outcome measures: Time to complete ulcer healing, patient health status, and recurrence of ulcers. Satisfaction with care, use of services, and personal costs were also monitored.
Results: The ulcers of patients in the clinic group tended to heal sooner than those in the control group over the whole 12 month follow up (log rank P=0.03). At 12 weeks, 34% of patients in the clinic group were healed compared with 24% in the control. The crude initial healing rate of ulcers in intervention compared with control patients was 1.45 (95% confidence interval 1.04 to 2.03). No significant differences were found between the groups in health status. Mean total NHS costs were £878.06 per year for the clinic group and £859.34 for the control (P=0.89).
Conclusions: Community based leg ulcer clinics with trained nurses using four layer bandaging is more effective than traditional home based treatment. This benefit is achieved at a small additional cost and could be delivered at reduced cost if certain service configurations were used
A Pinned Polymer Model of Posture Control
A phenomenological model of human posture control is posited. The dynamics
are modelled as an elastically pinned polymer under the influence of noise. The
model accurately reproduces the two-point correlation functions of experimental
posture data and makes predictions for the response function of the postural
control system. The physiological and clinical significance of the model is
discussed.Comment: uuencoded post script file, 17 pages with 3 figure
The Construction of Gauge-Links in Arbitrary Hard Processes
Transverse momentum dependent parton distribution and fragmentation functions
are described by hadronic matrix elements of bilocal products of field
operators off the light-cone. These bilocal products contain gauge-links, as
required by gauge-invariance. The gauge-links are path-ordered exponentials
connecting the field operators along a certain integration path. This
integration path is process-dependent, depending specifically on the
short-distance partonic subprocess. In this paper we present the technical
details needed in the calculation of the gauge-links and a calculational scheme
is provided to obtain the gauge-invariant distribution and fragmentation
correlators corresponding to a given partonic subprocess
Gauge Link Structure in Quark-Quark Correlators in hard processes
Distribution functions in hard processes can be described by quark-quark
correlators, nonlocal matrix elements of quark fields. Color gauge invariance
requires inclusion of appropriate gauge links in these correlators. For
transverse momentum dependent distribution functions, in particular important
for describing T-odd effects in hard processes, we find that new link
structures containing loops can appear in abelian and non-abelian theories. In
transverse moments, e.g. measured in azimuthal asymmetries, these loops may
enhance the contribution of gluonic poles. Some explicit results for the link
structure are given in high-energy leptoproduction and hadron-hadron
scattering.Comment: 9 pages, 9 figure
Wilson Lines off the Light-cone in TMD PDFs
Transverse Momentum Dependent (TMD) parton distribution functions (PDFs) also
take into account the transverse momentum () of the partons. The
-integrated analogues can be linked directly to quark and gluon matrix
elements using the operator product expansion in QCD, involving operators of
definite twist. TMDs also involve operators of higher twist, which are not
suppressed by powers of the hard scale, however. Taking into account gauge
links that no longer are along the light-cone, one finds that new distribution
functions arise. They appear at leading order in the description of azimuthal
asymmetries in high-energy scattering processes. In analogy to the collinear
operator expansion, we define a universal set of TMDs of definite rank and
point out the importance for phenomenology.Comment: 12 pages, presented by the first author at the Light-Cone Conference
2013, May 20-24, 2013, Skiathos, Greece. To be published in Few Body System
A comparison of algorithms for generating efficient choice experiments
Stated choice (SC) studies typically rely on the use of an underlying experimental design to construct the hypothetical choice situations shown to respondents. These designs are constructed by the analyst, with several different ways of constructing these designs having been proposed in the past. Recently, there has been a move from so-called orthogonal designs to more efficient designs. Efficient designs optimize the design such that the data will lead to more reliable parameter estimates for the model under consideration. The literature dealing with the generation of efficient designs has examined and largely solved the issue of a requirement for a prior knowledge of the parameter estimates that will be obtained post data collection. However, unlike orthogonal designs, the efficient design methodology requires the evaluation of a number of designs, and hence is computationally expensive to undertake. As such, the literature has suggested and implemented a number of algorithms to locate efficient designs for SC experiments. In this paper, we compare and contrast the performance of these algorithms as well as introduce two new algorithms
Next-to-leading Corrections to the Higgs Boson Transverse Momentum Spectrum in Gluon Fusion
We present a fully analytic calculation of the Higgs boson transverse
momentum and rapidity distributions, for nonzero Higgs , at
next-to-leading order in the infinite-top-mass approximation. We separate the
cross section into a part that contains the dominant soft, virtual, collinear,
and small--enhanced contributions, and the remainder, which is
organized by the contributions due to different parton helicities. We use this
cross section to investigate analytically the small- limit and compare
with the expectation from the resummation of large logarithms of the type
. We also compute numerically the cross section at moderate
where a fixed-order calculation is reliable. We find a -factor
that varies from , and a reduction in the scale dependence, as
compared to leading order. Our analysis suggests that the contribution of
current parton distributions to the total uncertainty on this cross section at
the LHC is probably less than that due to uncalculated higher orders.Comment: 40 pages, 10 figures, JHEP style (minor changes, added reference
Spin Two Glueball Mass and Glueball Regge Trajectory from Supergravity
We calculate the mass of the lowest lying spin two glueball in N=1 super
Yang-Mills from the dual Klebanov-Strassler background. We show that the Regge
trajectory obtained is linear; the 0++, 1-- and 2++ states lie on a line of
slope 0.23 -measured in units of the conifold deformation. We also compare mass
ratios with lattice data and find agreement within one standard deviation.Comment: 17 pages, 2 figure
Non-perturbative Heavy Quark Effective Theory
We explain how to perform non-perturbative computations in HQET on the
lattice. In particular the problem of the subtraction of power-law divergences
is solved by a non-perturbative matching of HQET and QCD. As examples, we
present a full calculation of the mass of the b-quark in the combined static
and quenched approximation and outline an alternative way to obtain the B-meson
decay constant at lowest order. Since no excessively large lattices are
required, our strategy can also be applied including dynamical fermions.Comment: 27 pages including figures and tables, latex2e; version published in
JHEP, typos corrected and 1 reference adde
A purely algebraic construction of a gauge and renormalization group invariant scalar glueball operator
This paper presents a complete algebraic proof of the renormalizability of
the gauge invariant operator to all orders of
perturbation theory in pure Yang-Mills gauge theory, whereby working in the
Landau gauge. This renormalization is far from being trivial as mixing occurs
with other gauge variant operators, which we identify explicitly. We
determine the mixing matrix to all orders in perturbation theory by using
only algebraic arguments and consequently we can uncover a renormalization
group invariant by using the anomalous dimension matrix derived from
. We also present a future plan for calculating the mass of the lightest
scalar glueball with the help of the framework we have set up.Comment: 17 page
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