1,651 research outputs found
Taming the -expansion with Large Spin Perturbation Theory
We apply analytic bootstrap techniques to the four-point correlator of
fundamental fields in the Wilson-Fisher model. In an -expansion
crossing symmetry fixes the double discontinuity of the correlator in terms of
CFT data at lower orders. Large spin perturbation theory, or equivalently the
recently proposed Froissart-Gribov inversion integral, then allows one to
reconstruct the CFT data of intermediate operators of any spin. We use this
method to compute the anomalous dimensions and OPE coefficients of leading
twist operators. To cubic order in the double discontinuity arises
solely from the identity operator and the scalar bilinear operator, making the
computation straightforward. At higher orders the double discontinuity receives
contributions from infinite towers of higher spin operators. At fourth order,
the structure of perturbation theory leads to a proposal in terms of functions
of certain degree of transcendentality, which can then be fixed by symmetries.
This leads to the full determination of the CFT data for leading twist
operators to fourth order.Comment: 16 pages. v2: Added discussion on low spin spectru
Increasing the Reliability of Adaptive Quadrature Using Explicit Interpolants
We present two new adaptive quadrature routines. Both routines differ from
previously published algorithms in many aspects, most significantly in how they
represent the integrand, how they treat non-numerical values of the integrand,
how they deal with improper divergent integrals and how they estimate the
integration error. The main focus of these improvements is to increase the
reliability of the algorithms without significantly impacting their efficiency.
Both algorithms are implemented in Matlab and tested using both the "families"
suggested by Lyness and Kaganove and the battery test used by Gander and
Gautschi and Kahaner. They are shown to be more reliable, albeit in some cases
less efficient, than other commonly-used adaptive integrators.Comment: 32 pages, submitted to ACM Transactions on Mathematical Softwar
An alternative to diagrams for the critical O(N) model: dimensions and structure constants to order
We apply the methods of modern analytic bootstrap to the critical
model in a expansion. At infinite the model possesses higher spin
symmetry which is weakly broken as we turn on . By studying consistency
conditions for the correlator of four fundamental fields we derive the CFT-data
for all the (broken) currents to order , and the CFT-data for the
non-singlet currents to order . To order our results are in
perfect agreement with those in the literature. To order we reproduce
known results for anomalous dimensions and obtain a variety of new results for
structure constants, including the global symmetry central charge to this
order.Comment: 32 pages + appendices, 2 figures. v2: Improved presentation + new
appendix considering mixed correlator. Version to appear in JHE
Who Is In Charge, and Who Should Be? The Disciplinary Role of the Commander in Military Justice Systems
BackgroundStandard therapy for newly diagnosed glioblastoma is radiotherapy plus temozolomide. In this phase 3 study, we evaluated the effect of the addition of bevacizumab to radiotherapy-temozolomide for the treatment of newly diagnosed glioblastoma. MethodsWe randomly assigned patients with supratentorial glioblastoma to receive intravenous bevacizumab (10 mg per kilogram of body weight every 2 weeks) or placebo, plus radiotherapy (2 Gy 5 days a week; maximum, 60 Gy) and oral temozolomide (75 mg per square meter of body-surface area per day) for 6 weeks. After a 28-day treatment break, maintenance bevacizumab (10 mg per kilogram intravenously every 2 weeks) or placebo, plus temozolomide (150 to 200 mg per square meter per day for 5 days), was continued for six 4-week cycles, followed by bevacizumab monotherapy (15 mg per kilogram intravenously every 3 weeks) or placebo until the disease progressed or unacceptable toxic effects developed. The coprimary end points were investigator-assessed progression-free survival and overall survival. ResultsA total of 458 patients were assigned to the bevacizumab group, and 463 patients to the placebo group. The median progression-free survival was longer in the bevacizumab group than in the placebo group (10.6 months vs. 6.2 months; stratified hazard ratio for progression or death, 0.64; 95% confidence interval [CI], 0.55 to 0.74; P<0.001). The benefit with respect to progression-free survival was observed across subgroups. Overall survival did not differ significantly between groups (stratified hazard ratio for death, 0.88; 95% CI, 0.76 to 1.02; P=0.10). The respective overall survival rates with bevacizumab and placebo were 72.4% and 66.3% at 1 year (P=0.049) and 33.9% and 30.1% at 2 years (P=0.24). Baseline health-related quality of life and performance status were maintained longer in the bevacizumab group, and the glucocorticoid requirement was lower. More patients in the bevacizumab group than in the placebo group had grade 3 or higher adverse events (66.8% vs. 51.3%) and grade 3 or higher adverse events often associated with bevacizumab (32.5% vs. 15.8%). ConclusionsThe addition of bevacizumab to radiotherapy-temozolomide did not improve survival in patients with glioblastoma. Improved progression-free survival and maintenance of baseline quality of life and performance status were observed with bevacizumab; however, the rate of adverse events was higher with bevacizumab than with placebo.
Efficient red electroluminescence from diketopyrrolopyrrole copolymerised with a polyfluorene
We thank the EC Seventh Framework Programme (FP7/2007-2013) under Grant Agreement No. 212311 (ONE-P), the RTN THREADMILL (EU-Contract No.: MRTN-CT-2006-036040), the ITNs SUPERIOR (PITN-CT-2009-238177), and CONTEST (PITN-CT-2012-317488) as well as the Royal Society, and EPSRC for funding
Cosmic shear requirements on the wavelength-dependence of telescope point spread functions
Cosmic shear requires high precision measurement of galaxy shapes in the
presence of the observational Point Spread Function (PSF) that smears out the
image. The PSF must therefore be known for each galaxy to a high accuracy.
However, for several reasons, the PSF is usually wavelength dependent,
therefore the differences between the spectral energy distribution of the
observed objects introduces further complexity. In this paper we investigate
the effect of the wavelength-dependence of the PSF, focusing on instruments in
which the PSF size is dominated by the diffraction-limit of the telescope and
which use broad-band filters for shape measurement.
We first calculate biases on cosmological parameter estimation from cosmic
shear when the stellar PSF is used uncorrected. Using realistic galaxy and star
spectral energy distributions and populations and a simple three-component
circular PSF we find that the colour-dependence must be taken into account for
the next generation of telescopes. We then consider two different methods for
removing the effect (i) the use of stars of the same colour as the galaxies and
(ii) estimation of the galaxy spectral energy distribution using multiple
colours and using a telescope model for the PSF. We find that both of these
methods correct the effect to levels below the tolerances required for per-cent
level measurements of dark energy parameters. Comparison of the two methods
favours the template-fitting method because its efficiency is less dependent on
galaxy redshift than the broad-band colour method and takes full advantage of
deeper photometry.Comment: 10 pages, 8 figures, version accepted for publication in MNRA
Classical novae from the POINT-AGAPE microlensing survey of M31 -- I. The nova catalogue
The POINT-AGAPE survey is an optical search for gravitational microlensing
events towards the Andromeda Galaxy (M31). As well as microlensing, the survey
is sensitive to many different classes of variable stars and transients. Here
we describe the automated detection and selection pipeline used to identify M31
classical novae (CNe) and we present the resulting catalogue of 20 CN
candidates observed over three seasons. CNe are observed both in the bulge
region as well as over a wide area of the M31 disk. Nine of the CNe are caught
during the final rise phase and all are well sampled in at least two colours.
The excellent light-curve coverage has allowed us to detect and classify CNe
over a wide range of speed class, from very fast to very slow. Among the
light-curves is a moderately fast CN exhibiting entry into a deep transition
minimum, followed by its final decline. We have also observed in detail a very
slow CN which faded by only 0.01 mag day over a 150 day period. We
detect other interesting variable objects, including one of the longest period
and most luminous Mira variables. The CN catalogue constitutes a uniquely
well-sampled and objectively-selected data set with which to study the
statistical properties of classical novae in M31, such as the global nova rate,
the reliability of novae as standard-candle distance indicators and the
dependence of the nova population on stellar environment. The findings of this
statistical study will be reported in a follow-up paper.Comment: 21 pages, 13 figures, re-submitted for publication in MNRAS, typos
corrected, references updated, figures 5-9 made cleare
Proinsulin C-peptide elicits disaggregation of insulin resulting in enhanced physiological insulin effects
Using surface plasmon resonance (SPR) and electrospray mass spectrometry (ESI-MS), proinsulin C-peptide was found to influence insulin-insulin interactions. In SPR with chip-bound insulin, C-peptide mixed with analyte insulin increased the binding, while alone C-peptide did not. A control peptide with the same residues in random sequence had little effect. In ESI-MS, C-peptide lowered the presence of insulin hexamer. The data suggest that C-peptide promotes insulin disaggregation. Insulin/insulin oligomer μM dissociation constants were determined. Compatible with these findings, type 1 diabetic patients receiving insulin and C-peptide developed 66% more stimulation of glucose metabolism than when given insulin alone. A role of C-peptide in promoting insulin disaggregation may be important physiologically during exocytosis of pancreatic β-cell secretory granulae and pharmacologically at insulin injection sites. It is compatible with the normal co-release of C-peptide and insulin and may contribute to the beneficial effect of C-peptide and insulin replacement in type 1 diabetics
Diabetes: cost of illness in Norway
<p>Abstract</p> <p>Background</p> <p>Diabetes mellitus places a considerable burden on patients in terms of morbidity and mortality and on society in terms of costs. Costs related to diabetes are expected to increase due to increasing prevalence of type 2 diabetes. The aim of this study was to estimate the health care costs attributable to type 1 and type 2 diabetes in Norway in 2005.</p> <p>Methods</p> <p>Data on inpatient hospital services, outpatient clinic visits, physician services, drugs, medical equipment, nutrition guidance, physiotherapy, acupuncture, foot therapy and indirect costs were collected from national registers and responses to a survey of 584 patients with diabetes. The study was performed with a prevalence approach. Uncertainty was explored by means of bootstrapping.</p> <p>Results</p> <p>When hospital stays with diabetes as a secondary diagnosis were excluded, the total costs were €293 million, which represents about 1.4% of the total health care expenditure. Pharmaceuticals accounted for €95 million (32%), disability pensions €48 million (16%), medical devices €40 million (14%) and hospital admissions €21 million (7%). Patient expenditures for acupuncture, physiotherapy and foot therapy were many times higher than expenditure for nutritional guidance. Indirect costs (lost production from job absenteeism) accounted for €70.1 million (24% of the €293 million) and included sick leave (€16.7 million), disability support and disability pensions (€48.2 million) and other indirect costs (€5.3 million). If all diabetes related hospital stays are included (primary- and secondary diagnosis) total costs amounts to €535 million, about 2.6% of the total health care expenditure in Norway.</p> <p>Conclusions</p> <p>Diabetes represents a considerable burden to society in terms of health care costs and productivity losses.</p
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