15,991 research outputs found
Extended brief intervention to address alcohol misuse in people with mild to moderate intellectual disabilities living in the community (EBI-ID): study protocol for a randomised controlled trial.
There is some evidence that people with intellectual disabilities who live in the community are exposed to the same risks of alcohol use as the rest of the population. Various interventions have been evaluated in the general population to tackle hazardous or harmful drinking and alcohol dependence, but the literature evaluating interventions is very limited regarding intellectual disabilities. The National Institute for Health and Clinical Excellence recommends that brief and extended brief interventions be used to help young persons and adults who have screened as positive for hazardous and harmful drinking. The objective of this trial is to investigate the feasibility of adapting and delivering an extended brief intervention (EBI) to persons with mild/moderate intellectual disability who live in the community and whose level of drinking is harmful or hazardous
Wall slip and flow of concentrated hard-sphere colloidal suspensions
We present a comprehensive study of the slip and flow of concentrated
colloidal suspensions using cone-plate rheometry and simultaneous confocal
imaging. In the colloidal glass regime, for smooth, non-stick walls, the solid
nature of the suspension causes a transition in the rheology from
Herschel-Bulkley (HB) bulk flow behavior at large stress to a Bingham-like slip
behavior at low stress, which is suppressed for sufficient colloid-wall
attraction or colloid-scale wall roughness. Visualization shows how the
slip-shear transition depends on gap size and the boundary conditions at both
walls and that partial slip persist well above the yield stress. A
phenomenological model, incorporating the Bingham slip law and HB bulk flow,
fully accounts for the behavior. Microscopically, the Bingham law is related to
a thin (sub-colloidal) lubrication layer at the wall, giving rise to a
characteristic dependence of slip parameters on particle size and
concentration. We relate this to the suspension's osmotic pressure and yield
stress and also analyze the influence of van der Waals interaction. For the
largest concentrations, we observe non-uniform flow around the yield stress, in
line with recent work on bulk shear-banding of concentrated pastes. We also
describe residual slip in concentrated liquid suspensions, where the vanishing
yield stress causes coexistence of (weak) slip and bulk shear flow for all
measured rates
Curvature and Acoustic Instabilities in Rotating Fluid Disks
The stability of a rotating fluid disk to the formation of spiral arms is
studied in the tightwinding approximation in the linear regime. The dispersion
relation for spirals that was derived by Bertin et al. is shown to contain a
new, acoustic instability beyond the Lindblad resonances that depends only on
pressure and rotation. In this regime, pressure and gravity exchange roles as
drivers and inhibitors of spiral wave structures. Other instabilities that are
enhanced by pressure are also found in the general dispersion relation by
including higher order terms in the small parameter 1/kr for wavenumber k and
radius r. These instabilities are present even for large values of Toomre's
parameter Q. Unstable growth rates are determined in four cases: a
self-gravitating disk with a flat rotation curve, a self-gravitating disk with
solid body rotation, a non-self-gravitating disk with solid body rotation, and
a non-self-gravitating disk with Keplerian rotation. The most important
application appears to be as a source of spiral structure, possibly leading to
accretion in non-self-gravitating disks, such as some galactic nuclear disks,
disks around black holes, and proto-planetary disks. All of these examples have
short orbital times so the unstable growth time can be small.Comment: 30 pages, 5 figures, scheduled for ApJ 520, August 1, 199
On the Prospects for Laser Cooling of TlF
We measure the upper state lifetime and two ratios of vibrational branching
fractions f_{v'v} on the B^{3}\Pi_{1}(v') - X^{1}\Sigma^{+}(v) transition of
TlF. We find the B state lifetime to be 99(9) ns. We also determine that the
off-diagonal vibrational decays are highly suppressed: f_{01}/f_{00} <
2x10^{-4} and f_{02}/f_{00} = 1.10(6)%, in excellent agreement with their
predicted values of f_{01}/f_{00} < 8x10^{-4} and f_{02}/f_{00} = 1.0(2)% based
on Franck-Condon factors calculated using Morse and RKR potentials. The
implications of these results for the possible laser cooling of TlF and
fundamental symmetries experiments are discussed.Comment: 5 pages, 2 figure
Equation level matching: An extension of the method of matched asymptotic expansion for problems of wave propagation
We introduce an alternative to the method of matched asymptotic expansions.
In the "traditional" implementation, approximate solutions, valid in different
(but overlapping) regions are matched by using "intermediate" variables. Here
we propose to match at the level of the equations involved, via a "uniform
expansion" whose equations enfold those of the approximations to be matched.
This has the advantage that one does not need to explicitly solve the
asymptotic equations to do the matching, which can be quite impossible for some
problems. In addition, it allows matching to proceed in certain wave situations
where the traditional approach fails because the time behaviors differ (e.g.,
one of the expansions does not include dissipation). On the other hand, this
approach does not provide the fairly explicit approximations resulting from
standard matching. In fact, this is not even its aim, which to produce the
"simplest" set of equations that capture the behavior
Star polymers: A study of the structural arrest in presence of attractive interactions
Simulations and Mode-Coupling Theory calculations, for a large range of the
arm number and packing fraction have shown that the structural
arrest and the dynamics of star polymers in a good solvent are extremely rich:
the systems show a reentrant melting of the disordered glass nested between two
stable fluid phases that strongly resemble the equilibrium phase diagram.
Starting from a simple model potential we investigate the effect of the
interplay between attractive interactions of different range and ultrasoft core
repulsion, on the dynamics and on the occurrence of the ideal glass transition
line. In the two cases considered so far, we observed some significant
differences with respect to the purely repulsive pair interaction. We also
discuss the interplay between equilibrium and non equilibrium phase behavior.
The accuracy of the theoretical tools we utilized in our investigation has been
checked by comparing the results with molecular dynamics simulations.Comment: 24 pages, 14 figures, accepted for publication in Physical Review
Central Nervous System Parasitosis and Neuroinflammation Ameliorated by Systemic IL-10 Administration in Trypanosoma brucei-Infected Mice
Peer reviewedPublisher PD
Spitzer observations of the Massive star forming complex S254-S258: structure and evolution
We present Spitzer-IRAC, NOAO 2.1meter-Flamingos, Keck-NIRC, and
FCRAO-SEQUOIA observations of the massive star forming complex S254-S258,
covering an area of 25x20 arc-minutes. Using a combination of the IRAC and NIR
data, we identify and classify the young stellar objects (YSO) in the complex.
We detect 510 sources with near or mid IR-excess, and we classify 87 Class I,
and 165 Class II sources. The YSO are found in clusters surrounded by isolated
YSO in a low-density distributed population. The ratio of clustered to total
YSO is 0.8. We identify six new clusters in the complex. One of them,
G192.63-00, is located around the ionizing star of the HII region S255. We
hypothesize that the ionizing star of S255 was formed in this cluster. We also
detect a southern component of the cluster in HII region S256. The cluster
G192.54-0.15, located inside HII region S254 has a VLSR of 17 km/s with respect
to the main cloud, and we conclude that it is located in the background of the
complex. The structure of the molecular cloud is examined using 12CO and 13CO,
as well as a near-IR extinction map. The main body of the molecular cloud has
VLSR between 5 and 9 km/s. The arc-shaped structure of the molecular cloud,
following the border of the HII regions, and the high column density in the
border of the HII regions support the idea that the material has been swept up
by the expansion of the HII regions.Comment: Accepted for publication in The Astrophysical Journa
Congenital bicuspid aortic valve: Differential prevalence across different South African population groups
On the Nonlocal Equations and Nonlocal Charges Associated with the Harry Dym Hierarchy
A large class of nonlocal equations and nonlocal charges for the Harry Dym
hierarchy is exhibited. They are obtained from nonlocal Casimirs associated
with its bi-Hamiltonian structure. The Lax representation for some of these
equations is also given.Comment: to appear in Journal of Mathematical Physics, 17 pages, Late
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