On the precision of chiral-dispersive calculations of ππ\pi\pi scattering

We calculate the combination $2a_0^{(0)}-5a_0^{(2)}$ (the Olsson sum rule) and the scattering lengths and effective ranges $a_1$, $a_2^{(I)}$ and $b_1$, $b_2^{(I)}$ dispersively (with the Froissart--Gribov representation) using, at low energy, the phase shifts for $\pi\pi$ scattering obtained by Colangelo, Gasser and Leutwyler (CGL) from the Roy equations and chiral perturbation theory, plus experiment and Regge behaviour at high energy, or directly, using the CGL parameters for $a$s and $b$s. We find mismatch, both among the CGL phases themselves and with the results obtained from the pion form factor. This reaches the level of several (2 to 5) standard deviations, and is essentially independent of the details of the intermediate energy region ($0.82\leq E\leq 1.42$ GeV) and, in some cases, of the high energy behaviour assumed. We discuss possible reasons for this mismatch, in particular in connection with an alternate set of phase shifts.Comment: Version to appear in Phys. Rev. D. Graphs and sum rule added. Plain TeX fil

Soliton Solutions for ABS Lattice Equations II: Casoratians and Bilinearization

In Part I [arXiv:0902.4873 [nlin.SI]] soliton solutions to the ABS list of multi-dimensionally consistent difference equations (except Q4) were derived using connection between the Q3 equation and the NQC equations, and then by reductions. In that work central role was played by a Cauchy matrix. In this work we use a different approach, we derive the $N$-soliton solutions following Hirota's direct and constructive method. This leads to Casoratians and bilinear difference equations. We give here details for the H-series of equations and for Q1; the results for Q3 have been given earlier.Comment: 36 page

Hypertension Guideline 2003 Update

Outcomes. Extensive data from many randomised controlled trials have shown the benefit of treating hypertension. The target blood pressure (BP) for antihypertensive management should be systolic BP < 140 mmHg, diastolic < 90 mmHg, with minimal or no drug side-effects. However, a lesser reduction will elicit benefit although this is not optimal. The reduction of BP in the elderly and in those with severe hypertension should be achieved gradually over 6 months. Stricter BP control is required for patients with end organ damage, co-existing risk factors and co-morbidity, e.g. diabetes mellitus. Co-existent risk factors should also be controlled.Benefits. Reduction in risk of stroke, cardiac failure, renal insufficiency and probably coronary artery disease. The major precautions and contraindications to each antihypertensive drug recommended are listed.Recommendations. Correct BP measurement procedure is described. Evaluation of cardiovascular risk factors and recommendations for antihypertensive therapy are stipulated. The total cardiovascular disease risk profile should be determined for all patients and this should inform management strategies. 'Lifestyle modification and patient education plays an essential role in the management strategy. Drug therapy: First line -low dose thiazide-like diuretics; second line -add one of the following: reserpine or β-blockers or ACE inhibitors or calcium channel blockers; third line - add another second line drug or hydralazine or α-blocker. The guideline includes management of specific situations, i.e. hypertensive emergency and urgency, severe hypertension with target organ damage and refractory hypertension (BP >160/95 mmHg on triple therapy), hypertension in diabetes mellitus, etc.Validity. Developed by the Working Groups established by the Executive Committee of the Southern African Hypertension Society with broader consensus meeting endorsement. The 2001 version was endorsed by the South African Medical Association Guideline Committee. The 2003 revisions were endorsed by the Executive Committee and a wider Working Group

An integrable multicomponent quad equation and its Lagrangian formulation

We present a hierarchy of discrete systems whose first members are the lattice modified Korteweg-de Vries equation, and the lattice modified Boussinesq equation. The N-th member in the hierarchy is an N-component system defined on an elementary plaquette in the 2-dimensional lattice. The system is multidimensionally consistent and a Lagrangian which respects this feature, i.e., which has the desirable closure property, is obtained.Comment: 10 page

A multidimensionally consistent version of Hirota's discrete KdV equation

A multidimensionally consistent generalisation of Hirota's discrete KdV equation is proposed, it is a quad equation defined by a polynomial that is quadratic in each variable. Soliton solutions and interpretation of the model as superposition principle are given. It is discussed how an important property of the defining polynomial, a factorisation of discriminants, appears also in the few other known discrete integrable multi-quadratic models.Comment: 11 pages, 2 figure

Improved fidelity of triggered entangled photons from single quantum dots

We demonstrate the on-demand emission of polarisation-entangled photon pairs from the biexciton cascade of a single InAs quantum dot embedded in a GaAs/AlAs planar microcavity. Improvements in the sample design blue shifts the wetting layer to reduce the contribution of background light in the measurements. Results presented show that >70% of the detected photon pairs are entangled. The high fidelity of the (|HxxHx>+|VxxVx>)/2^0.5 state that we determine is sufficient to satisfy numerous tests for entanglement. The improved quality of entanglement represents a significant step towards the realisation of a practical quantum dot source compatible with applications in quantum information.Comment: 9 pages. Paper is available free of charge at http://www.iop.org/EJ/abstract/1367-2630/8/2/029/, see also 'A semiconductor source of triggered entangled photon pairs', R. M. Stevenson et al., Nature 439, 179 (2006

Speech Communication

Contains reports on four research projects.National Institutes of Health (Grant 5 ROl NB04332-08)U.S. Air Force Cambridge Research Laboratories, Office of Aerospace Research, under Contract F19628-69-C-004