16,711 research outputs found
Obtaining Stiffness Exponents from Bond-diluted Lattice Spin Glasses
Recently, a method has been proposed to obtain accurate predictions for
low-temperature properties of lattice spin glasses that is practical even above
the upper critical dimension, . This method is based on the observation
that bond-dilution enables the numerical treatment of larger lattices, and that
the subsequent combination of such data at various bond densities into a
finite-size scaling Ansatz produces more robust scaling behavior. In the
present study we test the potential of such a procedure, in particular, to
obtain the stiffness exponent for the hierarchical Migdal-Kadanoff lattice.
Critical exponents for this model are known with great accuracy and any
simulations can be executed to very large lattice sizes at almost any bond
density, effecting a insightful comparison that highlights the advantages -- as
well as the weaknesses -- of this method. These insights are applied to the
Edwards-Anderson model in with Gaussian bonds.Comment: corrected version, 10 pages, RevTex4, 12 ps-figures included; related
papers available a http://www.physics.emory.edu/faculty/boettcher
Reduced healthcare utilisation following successful HCV treatment in HIV co-infected patients with mild liver disease
New direct-acting antivirals (DAA) for hepatitis C virus (HCV) infection have achieved high cure rates in many patient groups previously considered difficult-to-treat, including those HIV/HCV co-infected. The high price of these medications is likely to limit access to treatment, at least in the short term. Early treatment priority is likely to be given to those with advanced disease, but a more detailed understanding of the potential benefits in treating those with mild disease is needed. We hypothesized that successful HCV treatment within a co-infected population with mild liver disease would lead to a reduction in the use and costs of healthcare services in the 5 years following treatment completion. We performed a retrospective cohort study of HIV/HCV-co-infected patients without evidence of fibrosis/cirrhosis who received a course of HCV therapy between 2004 and 2013. Detailed analysis of healthcare utilization up to 5 years following treatment for each patient using clinical and electronic records was used to estimate healthcare costs. Sixty-three patients were investigated, of whom 48 of 63 (76.2%) achieved sustained virological response 12 weeks following completion of therapy (SVR12). Individuals achieving SVR12 incurred lower health utilization costs (£5000 per-patient) compared to (£10 775 per-patient) non-SVR patients in the 5 years after treatment. Healthcare utilization rates and costs in the immediate 5 years following treatment were significantly higher in co-infected patients with mild disease that failed to achieve SVR12. These data suggest additional value to achieving cure beyond the prevention of complications of disease
The Gravitational Lensing in the QSO 1208+10 from the Proximity Effect in its Lyman alpha Forest
The quasar Q1208+1011 (z_{em}=3.8) is the second highest redshift double
quasar ever detected. Several indications point toward it being a gravitational
lensed system, although a definitive proof is still lacking. We present new
evidence of its lensed nature based on the weakness of the ``proximity effect''
measured in the high resolution Lyman absorption spectrum of the QSO. A
luminosity amplification as large as 22 has been derived from this analysis.
Indications on the redshift of the lensing galaxy can be obtained from the
analysis of the intervening heavy element absorption systems discovered in the
QSO high resolution spectrum. On statistical and dynamical grounds a MgII
system present at z=1.13 appears as the most likely candidate for the lensing
galaxy. We compare the observed parameters with a simple isothermal model for
the lens to derive the properties of the lensing galaxy. The resulting
magnification factor is smaller, although marginally consistent with that
derived by the analysis of the proximity effect.Comment: 11 pages, 2 Postscript figures, ApJ in pres
Detecting z > 2 Type IIn Supernovae
Type IIn supernovae (SNe IIn) dominate the brightest supernova events in
observed FUV flux (~1200-2000A). We show that multi-band, multi-epoch optical
surveys complete to m_r = 27 can detect the FUV emission of ~25 z > 2 SNe IIn
deg^-2 yr^-1 rest-frame (~10 SNe IIn deg^-2 yr^-1 observed-frame) to 4 sigma
using a technique monitoring color-selected galaxies. Moreover, the strength
and evolution of the bright emission lines observed in low redshift SNe IIn
imply that the Ly-a emission features in ~70% of z > 2 SNe IIn are above
8m-class telescope spectroscopic thresholds for ~2 yr rest-frame. As a result,
existing facilities have the capability to both photometrically detect and
spectroscopically confirm z > 2 SNe IIn and pave the way for efficient searches
by future 8m-class survey and 30m-class telescopes. The method presented here
uses the sensitivities and wide-field capabilities of current optical
instruments and exploits (1) the efficiency of z > 2 galaxy color-selection
techniques, (2) the intrinsic brightness distribution ( = -19.0 +/-0.9)
and blue profile of SNe IIn continua, (3) the presence of extremely bright,
long-lived emission features, and (4) the potential to detect blueshifted SNe
Ly-a emission shortward of host galaxy Ly-a features.Comment: 26 pages (pre-print), 6 figures, accepted Ap
Phage display selected magnetite interacting Adhirons for shape controlled nanoparticle synthesis
Adhirons are robust, well expressing, peptide display scaffold proteins, developed as an effective alternative
to traditional antibody binding proteins for highly specific molecular recognition applications. This paper
reports for the first time the use of these versatile proteins for material binding, and as tools for
controlling material synthesis on the nanoscale. A phage library of Adhirons, each displaying two variable
binding loops, was screened to identify specific proteins able to interact with [100] faces of cubic
magnetite nanoparticles. The selected variable regions display a strong preference for basic residues
such as lysine. Molecular dynamics simulations of amino acid adsorption onto a [100] magnetite surface
provides a rationale for these interactions, with the lowest adsorption energy observed with lysine. These
proteins direct the shape of the forming nanoparticles towards a cubic morphology in room temperature
magnetite precipitation reactions, in stark contrast to the high temperature, harsh reaction conditions
currently used to produce cubic nanoparticles. These effects demonstrate the utility of the selected
Adhirons as novel magnetite mineralization control agents using ambient aqueous conditions. The
approach we outline with artificial protein scaffolds has the potential to develop into a toolkit of novel
additives for wider nanomaterial fabrication
Linear Response Calculations of Spin Fluctuations
A variational formulation of the time--dependent linear response based on the
Sternheimer method is developed in order to make practical ab initio
calculations of dynamical spin susceptibilities of solids. Using gradient
density functional and a muffin-tin-orbital representation, the efficiency of
the approach is demonstrated by applications to selected magnetic and strongly
paramagnetic metals. The results are found to be consistent with experiment and
are compared with previous theoretical calculations.Comment: 11 pages, RevTex; 3 Figures, postscript, high-resolution printing
(~1200dpi) is desire
A national survey of clinical practice for the management of whiplash-associated disorders in UK emergency departments
Objective: To undertake a national survey to determine current practice for the management of whiplash injuries in UK emergency departments (ED).
Methods: Postal questionnaire survey. 316 lead consultants from all UK ED with annual new attendances of over 50 000 people were asked to indicate the use of a range of treatments and the frequency with which these treatments were used. Samples of written advice were requested and content analysis was conducted and compared with survey responses.
Results: The response rate was 79% (251/316). The intervention most frequently used was verbal advice to exercise, reported by 84% of respondents for most or all cases, and advice against the use of a collar (83%). Other treatments reported as being used frequently were written advice and anti-inflammatory medication. 106 consultants (42%) provided a sample of written materials. Reference to expected recovery and encouragement for early return to activities were included in less than 6%. Nearly 50% of written materials contained information on how to use a soft collar and 61% contained information on solicitors and pursuing a personal injury claim. There were important differences between reported verbal behaviours and written advice.
Conclusion: Verbal advice is the primary method for managing whiplash injuries in ED and is usually supplemented by written advice. Within individual hospitals there is a lack of consistency between verbal and written advice. The promotion of personal injury claims is a common feature of written advice. Research is required to develop effective and consistent models of advice
Success and Growth of Corals Transplanted to Cement Armor Mat Tiles in Southeast Florida: Implications for Reef Restoration
In 1997, 271 scleractinian corals growing on a sewer outfall pipe were used in a transplantation study offshore from North Dade County, Florida, USA. Corals were removed from the outfall pipe and transplanted onto concrete armor mat tiles used to cover the pipe. Success (number of corals still attached and alive), mortality (number of dead corals), and growth rates of the transplants were assessed between December 1997 and December 1999. Colony surface area and radius length were measured on scanned photographs to estimate horizontal growth rate. After two years post-transplantation, success rate and overall mortality were 87% and 7.8% respectively. In comparison, seven sites of nearby natural substrate corals had mean success rates of 83% and mortality rates ranging from 11-17%. The two most numerous transplant species, Solenastrea bournoniand Siderastrea siderea, had comparable success and mortality rates; however, S. bournoni had a significantly faster growth rate (increase in horizontal radius and surface area). The colony size at time of transplantation was not related to the rate of growth; however, mortality and partial mortality rates increased with smaller size colonies. The methodology used in this investigation is useful for assessing transplanted corals because it is non-invasive, allows continual monitoring, and is applicable to corals growing on natural and artificial substrates
- …