192 research outputs found
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Right Place, Right Time Commission: Call to Action
Report of the NHS Providers Commission on delayed transfers of care. The report examines the evidence for best practice in transfers of care across physical and mental health
Formation of runoff at the hillslope scale during intense precipitation
On 60 m<sup>2</sup> hillslope plots, at 18 mainly grassland locations in Switzerland rain was applied at rates of 50–100 mm/h for between 3 and 6 h. The generated flows were measured, including overland flow, near surface and subsurface flow 0.5–1.3 m below the surface. At some locations less than 2% of the rain flowed down the slope either on or below the surface, whereas at some others more than 90% of the rain ran off. At the majority of sites most runoff was overland flow, though at a few sites subsurface flow, usually via macropores was dominant. Data collected during each of 48 high intensity sprinkling experiments were used to distinguish, which processes were dominant in each experiment. Which dominant and subsidiary processes occurred depended on interactions between infiltration rate, change in soil water storage and drainage of the soil water. These attributes were often not directly linked to parameters usually considered important like vegetation, slope, soil clay content and antecedent soil moisture. Considering the structure of the soil in combination with these attributes, process determination was in many cases fairly straightforward, indicating the possibility of reliably predicting runoff processes at a site. However, at some sites, effects occurred that were not easily recognizable and led to surprising results
Household transmission of invasive group A Streptococcus infections in England: a population-based study, 2009, 2011 to 13
Invasive group A s treptococcal infection has a 15% case fatality rate and a risk of secondary transmission. This retrospective study us ed two national data sources from England ; enhanced surveillance ( 2009) and a case management system ( 2011 - 13) to identify clusters of sever e group A streptococcal disease . 2 4 household pairs were identified. The median onset interval between cases was 2 days (range 0 - 28) with simultaneous onset in 8 pairs . The attack rate during the 30 days after first exposure to a primary case was 4 52 0 per 100000 person - years at risk (95% CI 2 900 - 673 0 ) a 19 40 ( 12 40 - 28 80 ) fold elevation over the background incidence . The theoretical number needed to treat ( NNT ) to prevent one secondary case using antibiotic prophylaxis was 2 71 ( 194 - 454 ) overall, 50 for mother - neonate pairs ( 2 7 - 3 93 ) and 8 2 for couples aged 75 years and over ( 46 - 417 ). Whilst a dramatic increased risk of infection was noted in all household contacts, increased ris k was greatest for mother - neonate pairs and couples aged 75 and over , suggesting targeted prophylaxis c ould be considered. Offering prophylaxis is challenging due to the short time interval between cases emphasising the importance of immediate notification and assessment of contacts
Domain Growth in a 1-D Driven Diffusive System
The low-temperature coarsening dynamics of a one-dimensional Ising model,
with conserved magnetisation and subject to a small external driving force, is
studied analytically in the limit where the volume fraction \mu of the minority
phase is small, and numerically for general \mu. The mean domain size L(t)
grows as t^{1/2} in all cases, and the domain-size distribution for domains of
one sign is very well described by the form P_l(l) \propto
(l/L^3)\exp[-\lambda(\mu)(l^2/L^2)], which is exact for small \mu (and possibly
for all \mu). The persistence exponent for the minority phase has the value 3/2
for \mu \to 0.Comment: 8 pages, REVTeX, 7 Postscript figures, uses multicol.sty and
epsf.sty. Submitted to Phys. Rev.
Anomalous self-diffusion in the ferromagnetic Ising chain with Kawasaki dynamics
We investigate the motion of a tagged spin in a ferromagnetic Ising chain
evolving under Kawasaki dynamics. At equilibrium, the displacement is Gaussian,
with a variance growing as . The temperature dependence of the
prefactor is derived exactly. At low temperature, where the static
correlation length is large, the mean square displacement grows as
in the coarsening regime, i.e., as a finite fraction of the
mean square domain length. The case of totally asymmetric dynamics, where
(resp. ) spins move only to the right (resp. to the left), is also
considered. In the steady state, the displacement variance grows as . The temperature dependence of the prefactor is derived exactly,
using the Kardar-Parisi-Zhang theory. At low temperature, the displacement
variance grows as in the coarsening regime, again proportionally to
the mean square domain length.Comment: 22 pages, 8 figures. A few minor changes and update
From urn models to zero-range processes: statics and dynamics
The aim of these lecture notes is a description of the statics and dynamics
of zero-range processes and related models. After revisiting some conceptual
aspects of the subject, emphasis is then put on the study of the class of
zero-range processes for which a condensation transition arises.Comment: Lecture notes for the Luxembourg Summer School 200
New Dynamic Monte Carlo Renormalization Group Method
The dynamical critical exponent of the two-dimensional spin-flip Ising model
is evaluated by a Monte Carlo renormalization group method involving a
transformation in time. The results agree very well with a finite-size scaling
analysis performed on the same data. The value of is
obtained, which is consistent with most recent estimates
Transverse-field Ising spin chain with inhomogeneous disorder
We consider the critical and off-critical properties at the boundary of the
random transverse-field Ising spin chain when the distribution of the couplings
and/or transverse fields, at a distance from the surface, deviates from its
uniform bulk value by terms of order with an amplitude . Exact
results are obtained using a correspondence between the surface magnetization
of the model and the surviving probability of a random walk with time-dependent
absorbing boundary conditions. For slow enough decay, , the
inhomogeneity is relevant: Either the surface stays ordered at the bulk
critical point or the average surface magnetization displays an essential
singularity, depending on the sign of . In the marginal situation,
, the average surface magnetization decays as a power law with a
continuously varying, -dependent, critical exponent which is obtained
analytically. The behavior of the critical and off-critical autocorrelation
functions as well as the scaling form of the probability distributions for the
surface magnetization and the first gaps are determined through a
phenomenological scaling theory. In the Griffiths phase, the properties of the
Griffiths-McCoy singularities are not affected by the inhomogeneity. The
various results are checked using numerical methods based on a mapping to free
fermions.Comment: 11 pages (Revtex), 11 figure
Clinical use of HIV integrase inhibitors : a systematic review and meta-analysis
Background: Optimal regimen choice of antiretroviral therapy is essential to achieve long-term clinical success. Integrase inhibitors have swiftly been adopted as part of current antiretroviral regimens. The purpose of this study was to review the evidence for integrase inhibitor use in clinical settings.
Methods: MEDLINE and Web-of-Science were screened from April 2006 until November 2012, as were hand-searched scientific meeting proceedings. Multiple reviewers independently screened 1323 citations in duplicate to identify randomized controlled trials, nonrandomized controlled trials and cohort studies on integrase inhibitor use in clinical practice. Independent, duplicate data extraction and quality assessment were conducted.
Results: 48 unique studies were included on the use of integrase inhibitors in antiretroviral therapy-naive patients and treatment-experienced patients with either virological failure or switching to integrase inhibitors while virologically suppressed. On the selected studies with comparable outcome measures and indication (n = 16), a meta-analysis was performed based on modified intention-to-treat (mITT), on-treatment (OT) and as-treated (AT) virological outcome data. In therapy-naive patients, favorable odds ratios (OR) for integrase inhibitor-based regimens were observed, (mITT OR 0.71, 95% CI 0.59-0.86). However, integrase inhibitors combined with protease inhibitors only did not result in a significant better virological outcome. Evidence further supported integrase inhibitor use following virological failure (mITT OR 0.27; 95% CI 0.11-0.66), but switching to integrase inhibitors from a high genetic barrier drug during successful treatment was not supported (mITT OR 1.43; 95% CI 0.89-2.31). Integrase inhibitor-based regimens result in similar immunological responses compared to other regimens. A low genetic barrier to drug-resistance development was observed for raltegravir and elvitegravir, but not for dolutegravir.
Conclusion: In first-line therapy, integrase inhibitors are superior to other regimens. Integrase inhibitor use after virological failure is supported as well by the meta-analysis. Careful use is however warranted when replacing a high genetic barrier drug in treatment-experienced patients switching successful treatment
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