6,366 research outputs found
Facilitating return to work through early specialist health-based interventions (FRESH): protocol for a feasibility randomised controlled trial
Background
Over one million people sustain traumatic brain injury each year in the UK and more than 10 % of these are moderate or severe injuries, resulting in cognitive and psychological problems that affect the ability to work. Returning to work is a primary rehabilitation goal but fewer than half of traumatic brain injury survivors achieve this. Work is a recognised health service outcome, yet UK service provision varies widely and there is little robust evidence to inform rehabilitation practice. A single-centre cohort comparison suggested better work outcomes may be achieved through early occupational therapy targeted at job retention. This study aims to determine whether this intervention can be delivered in three new trauma centres and to conduct a feasibility, randomised controlled trial to determine whether its effects and cost effectiveness can be measured to inform a definitive trial.
Methods/design
Mixed methods study, including feasibility randomised controlled trial, embedded qualitative studies and feasibility economic evaluation will recruit 102 people with traumatic brain injury and their nominated carers from three English UK National Health Service (NHS) trauma centres. Participants will be randomised to receive either usual NHS rehabilitation or usual rehabilitation plus early specialist traumatic brain injury vocational rehabilitation delivered by an occupational therapist. The primary objective is to assess the feasibility of conducting a definitive trial; secondary objectives include measurement of protocol integrity (inclusion/exclusion criteria, intervention adherence, reasons for non-adherence) recruitment rate, the proportion of eligible patients recruited, reasons for non-recruitment, spectrum of TBI severity, proportion of and reasons for loss to follow-up, completeness of data collection, gains in face-to-face Vs postal data collection and the most appropriate methods of measuring primary outcomes (return to work, retention) to determine the sample size for a larger trial.
Discussion
To our knowledge, this is the first feasibility randomised controlled trial of a vocational rehabilitation health intervention specific to traumatic brain injury. The results will inform the design of a definitive trial
New Soft Set Based Class of Linear Algebraic Codes
In this paper, we design and develop a new class of linear algebraic codes defined as soft linear algebraic codes using soft sets. The advantage of using these codes is that they have the ability to transmit m-distinct messages to m-set of receivers simultaneously. The methods of generating and decoding these new classes of soft linear algebraic codes have been developed. The notion of soft canonical generator matrix, soft canonical parity check matrix, and soft syndrome are defined to aid in construction and decoding of these codes. Error detection and correction of these codes are developed and illustrated by an example
Color superconductivity in weak coupling
We derive perturbatively the gap equations for a color-superconducting
condensate with total spin J=0 in dense QCD. At zero temperature, we confirm
the results of Son for the dependence of the condensate on the coupling
constant, and compute the prefactor to leading logarithmic accuracy. At nonzero
temperature, we find that to leading order in weak coupling, the temperature
dependence of the condensate is identical to that in BCS-like theories. The
condensates for total spin J=1 are classified; to leading logarithmic accuracy
these condensates are of the same order as those of spin J=0.Comment: 30 pages, 3 figures, RevTeX, epsf and psfig style files require
Lifetime Effects in Color Superconductivity at Weak Coupling
Present computations of the gap of color superconductivity in weak coupling
assume that the quarks which participate in the condensation process are
infinitely long-lived. However, the quasiparticles in a plasma are
characterized by having a finite lifetime. In this article we take into account
this fact to evaluate its effect in the computation of the color gap. By first
considering the Schwinger-Dyson equations in weak coupling, when one-loop
self-energy corrections are included, a general gap equation is written in
terms of the spectral densities of the quasiparticles. To evaluate lifetime
effects, we then model the spectral density by a Lorentzian function. We argue
that the decay of the quasiparticles limits their efficiency to condense. The
value of the gap at the Fermi surface is then reduced. To leading order, these
lifetime effects can be taken into account by replacing the coupling constant
of the gap equation by a reduced effective one.Comment: 16 pages, 2 figures; explanations on the role of the Meissner effect
added; 2 references added; accepted for publication in PR
Lattice gauge theory with baryons at strong coupling
We study the effective Hamiltonian for strong-coupling lattice QCD in the
case of non-zero baryon density. In leading order the effective Hamiltonian is
a generalized antiferromagnet. For naive fermions, the symmetry is U(4N_f) and
the spins belong to a representation that depends on the local baryon number.
Next-nearest-neighbor (nnn) terms in the Hamiltonian break the symmetry to
U(N_f) x U(N_f). We transform the quantum problem to a Euclidean sigma model
which we analyze in a 1/N_c expansion. In the vacuum sector we recover
spontaneous breaking of chiral symmetry for the nearest-neighbor and nnn
theories. For non-zero baryon density we study the nearest-neighbor theory
only, and show that the pattern of spontaneous symmetry breaking depends on the
baryon density.Comment: 31 pages, 5 EPS figures. Corrected Eq. (6.1
Polymer transport in random flow
The dynamics of polymers in a random smooth flow is investigated in the
framework of the Hookean dumbbell model. The analytical expression of the
time-dependent probability density function of polymer elongation is derived
explicitly for a Gaussian, rapidly changing flow. When polymers are in the
coiled state the pdf reaches a stationary state characterized by power-law
tails both for small and large arguments compared to the equilibrium length.
The characteristic relaxation time is computed as a function of the Weissenberg
number. In the stretched state the pdf is unstationary and exhibits
multiscaling. Numerical simulations for the two-dimensional Navier-Stokes flow
confirm the relevance of theoretical results obtained for the delta-correlated
model.Comment: 28 pages, 6 figure
Holographic dilepton production in a thermalizing plasma
We determine the out-of-equilibrium production rate of dileptons at rest in
strongly coupled N=4 Super Yang-Mills plasma using the AdS/CFT correspondence.
Thermalization is achieved via the gravitational collapse of a thin shell of
matter in AdS_5 space and the subsequent formation of a black hole, which we
describe in a quasistatic approximation. Prior to thermalization, the dilepton
spectral function is observed to oscillate as a function of frequency, but the
amplitude of the oscillations decreases when thermal equilibrium is approached.
At the same time, we follow the flow of the quasinormal spectrum of the
corresponding U(1) vector field towards its equilibrium limit.Comment: 21 pages, 7 figures. v2: Version accepted for publication in JHEP;
minor modifications, added reference
Debye screening and Meissner effect in a three-flavor color superconductor
I compute the gluon self-energy in a color superconductor with three flavors
of massless quarks, where condensation of Cooper pairs breaks the color and
flavor SU(3)_c x U(3)_V x U(3)_A symmetry of QCD to the diagonal subgroup
SU(3)_{c+V}. At zero temperature, all eight electric gluons obtain a Debye
screening mass, and all eight magnetic gluons a Meissner mass. The Debye as
well as the Meissner masses are found to be equal for the different gluon
colors. These masses determine the coefficients of the kinetic terms in the
effective theory for the low-energy degrees of freedom. Their values agree with
those obtained by Son and Stephanov.Comment: 10 pages, 1 figure (eps
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