Resummation of Threshold, Low- and High-Energy Expansions for Heavy-Quark Correlators

With the help of the Mellin-Barnes transform, we show how to simultaneously resum the expansion of a heavy-quark correlator around q^2=0 (low-energy), q^2= 4 m^2 (threshold, where m is the quark mass) and q^2=-\infty (high-energy) in a systematic way. We exemplify the method for the perturbative vector correlator at O(alpha_s^2) and O(alpha_s^3). We show that the coefficients, Omega(n), of the Taylor expansion of the vacuum polarization function in terms of the conformal variable \omega admit, for large n, an expansion in powers of 1/n (up to logarithms of n) that we can calculate exactly. This large-n expansion has a sign-alternating component given by the logarithms of the OPE, and a fixed-sign component given by the logarithms of the threshold expansion in the external momentum q^2.Comment: 27 pages, 8 figures. We fix typos in Eqs. (18), (27), (55) and (56). Results unchange

Proper Eighth-Order Vacuum-Polarization Function and its Contribution to the Tenth-Order Lepton g-2

This paper reports the Feynman-parametric representation of the vacuum-polarization function consisting of 105 Feynman diagrams of the eighth order, and its contribution to the gauge-invariant set called Set I(i) of the tenth-order lepton anomalous magnetic moment. Numerical evaluation of this set is carried out using FORTRAN codes generated by an automatic code generation system gencodevpN developed specifically for this purpose. The contribution of diagrams containing electron loop to the electron g-2 is 0.017 47 (11) (alpha/pi)^5. The contribution of diagrams containing muon loop is 0.000 001 67 (3) (alpha/pi)^5. The contribution of tau-lepton loop is negligible at present. The sum of all these terms is 0.017 47 (11) (alpha/pi)^5. The contribution of diagrams containing electron loop to the muon g-2 is 0.087 1 (59) (alpha/pi)^5. That of tau-lepton loop is 0.000 237 (1) (alpha/pi)^5. The total contribution to a_mu, the sum of these terms and the mass-independent term, is 0.104 8 (59) (alpha/pi)^5.Comment: 48 pages, 6 figures. References are correcte

Tenth-Order Lepton Anomalous Magnetic Moment -- Sixth-Order Vertices Containing Vacuum-Polarization Subdiagrams

This paper reports the values of contributions to the electron g-2 from 300 Feynman diagrams of the gauge-invariant Set III(a) and 450 Feynman diagrams of the gauge-invariant Set III(b). The evaluation is carried out in two versions. Version A is to start from the sixth-order magnetic anomaly M_6 obtained in the previous work. The mass-independent contributions of Set III(a) and Set III(b) are 2.1275 (2) and 3.3271 (6) in units of (alpha/pi)^5, respectively. Version B is based on the recently-developed automatic code generation scheme. This method yields 2.1271 (3) and 3.3271 (8) in units of (alpha/pi)^5, respectively. They are in excellent agreement with the results of the first method within the uncertainties of numerical integration. Combining these results as statistically independent we obtain the best values, 2.1273 (2), and 3.3271 (5) times (alpha/pi)^5, for the mass-independent contributions of the Set III(a) and Set III(b), respectively. We have also evaluated mass-dependent contributions of diagrams containing muon and/or tau-particle loop. Including them the total contribution of Set III(a) is 2.1349 (2) and that of Set III(b) is 3.3299 (5) in units of (alpha/pi)^5. The total contributions to the muon g-2 of various leptonic vacuum-polarization loops of Set III(a) and Set III(b) are 112.418 (32) and 15.407 (5) in units of (alpha/pi)^5, respectively.Comment: 31 pages, 4 figure

Association of Down's syndrome and water fluoride level: a systematic review of the evidence

BACKGROUND: A review of the safety and efficacy of drinking water fluoridation was commissioned by the UK Department of Health to investigate whether the evidence supported a beneficial effect of water fluoridation and whether there was any evidence of adverse effects. Down's syndrome was one of the adverse effects reported. The aim of this review is to examine the evidence for an association between water fluoride level and Down's syndrome. METHODS: A systematic review of research. Studies were identified through a comprehensive literature search, scanning citations and online requests for papers. Studies in all languages which investigated the incidence of Down's syndrome in areas with different levels of fluoride in their water supplies were included. Study inclusion and quality was assessed independently by 2 reviewers. A qualitative analysis was conducted. RESULTS: Six studies were included. All were ecological in design and scored poorly on the validity assessment. The estimates of the crude relative risk ranged from 0.84 to 3.0. Four studies showed no significant associations between the incidence of Down's syndrome and water fluoride level and two studies by the same author found a significant (p < 0.05) positive association (increased Down's syndrome incidence with increased water fluoride level). Only two of the studies controlled for confounding factors and only one of these presented summary outcome measures. CONCLUSIONS: The evidence of an association between water fluoride level and Down's syndrome incidence is inconclusive

Lectures on localization and matrix models in supersymmetric Chern-Simons-matter theories

In these lectures I give a pedagogical presentation of some of the recent progress in supersymmetric Chern-Simons-matter theories, coming from the use of localization and matrix model techniques. The goal is to provide a simple derivation of the exact interpolating function for the free energy of ABJM theory on the three-sphere, which implies in particular the N^{3/2} behavior at strong coupling. I explain in detail part of the background needed to understand this derivation, like holographic renormalization, localization of path integrals, and large N techniques in matrix modelsComment: 73 pages, 7 figures. v2: references and clarifications added, misprints corrected. v3: more references, clarifications, and corrections. v4: more corrections and clarifications, final version to appear in J. Phys.

Effects of interacting networks of cardiovascular risk genes on the risk of type 2 diabetes mellitus (the CODAM study)

Background: Genetic dissection of complex diseases requires innovative approaches for identification of disease-predisposing genes. A well-known example of a human complex disease with a strong genetic component is Type 2 Diabetes Mellitus (T2DM). Methods: We genotyped normal-glucose-tolerant subjects (NGT; n = 54), subjects with an impaired glucose metabolism (IGM; n = 111) and T2DM (n = 142) subjects, in an assay (designed by Roche Molecular Systems) for detection of 68 polymorphisms in 36 cardiovascular risk genes. Using the single-locus logistic regression and the so-called haplotype entropy, we explored the possibility that (1) common pathways underlie development of T2DM and cardiovascular disease which would imply enrichment of cardiovascular risk polymorphisms in "pre-diabetic" (IGM) and diabetic (T2DM) populations- and (2) that gene-gene interactions are relevant for the effects of risk polymorphisms. Results: In single-locus analyses, we showed suggestive association with disturbed glucose metabolism (i.e. subjects who were either IGM or had T2DM), or with T2DM only. Moreover, in the haplotype entropy analysis, we identified a total of 14 pairs of polymorphisms (with a false discovery rate of 0.125) that may confer risk of disturbed glucose metabolism, or T2DM only, as members of interacting networks of genes. We substantiated gene-gene interactions by showing that these interacting networks can indeed identify potential "disease-predisposing allele-combinations". Conclusion: Gene-gene interactions of cardiovascular risk polymorphisms can be detected in prediabetes and T2DM, supporting the hypothesis that common pathways may underlie development of T2DM and cardiovascular disease. Thus, a specific set of risk polymorphisms, when simultaneously present, increases the risk of disease and hence is indeed relevant in the transfer of risk

HMG CoA reductase inhibitors (statins) to treat Epstein–Barr virus-driven lymphoma

While statins have been highly effective for lowering serum cholesterol and reducing the incidence of coronary events, they have multiple other effects. Certain statins block the interaction of adhesion molecules that are important for cell–cell interactions including those between EBV-transformed B cells. These same statins inhibit NF-κB activation in the cells and induce apoptosis of transformed B cells. Studies in severe combined immunodeficiency mice show that simvastatin delays the development of EBV-lymphomas in these animals. These statins might be considered for the treatment of EBV-lymphomas in selected patients

A Ligand Peptide Motif Selected from a Cancer Patient Is a Receptor-Interacting Site within Human Interleukin-11

Interleukin-11 (IL-11) is a pleiotropic cytokine approved by the FDA against chemotherapy-induced thrombocytopenia. From a combinatorial selection in a cancer patient, we isolated an IL-11-like peptide mapping to domain I of the IL-11 (sequence CGRRAGGSC). Although this motif has ligand attributes, it is not within the previously characterized interacting sites. Here we design and validate in-tandem binding assays, site-directed mutagenesis and NMR spectroscopy to show (i) the peptide mimics a receptor-binding site within IL-11, (ii) the binding of CGRRAGGSC to the IL-11Rα is functionally relevant, (iii) Arg4 and Ser8 are the key residues mediating the interaction, and (iv) the IL-11-like motif induces cell proliferation through STAT3 activation. These structural and functional results uncover an as yet unrecognized receptor-binding site in human IL-11. Given that IL-11Rα has been proposed as a target in human cancer, our results provide clues for the rational design of targeted drugs