Axial anomaly and the precise value of the π0→2γ\pi^0 \to 2 \gamma decay width

The anomaly in the vacuum expectation value of the product of axial and two vector currents (AVV) in QCD is investigated. The goal is to determine from its value the $\pi^0 \to 2 \gamma$ decay width with high precision. The sum rule for AVV formfactor is studied. The difference $f_{\pi^0} - f_{\pi^+}$ caused by strong interaction is calculated and appears to be small. The $\pi^0 - \eta$ mixing is accounted. The $\pi^0 \to 2 \gamma$ decay width determined theoretically from the axial anomaly is found to be $\Gamma(\pi^0 \to 2 \gamma) = 7.93 eV$ with an error $\sim 1.5$. The measurement of the $\pi^0 \to 2 \gamma$ decay width at the same level of accuracy would allow one to achieve a high precision test of QCD.Comment: 8 pages, few misprints are correcte

The Athena X-ray Integral Field Unit: a consolidated design for the system requirement review of the preliminary definition phase

Instrumentatio

Insulin resistance in relation to melanoma risk

Obesity, deregulation of adipocytokines, and insulin resistance are interrelated and have been implicated in carcinogenesis. In search of novel risk factors for melanoma, we explored the association of this disease with insulin resistance in a small size, case-control study. Homeostasis Model Assessment for Insulin Resistance (HOMA-IR), serum leptin, and adiponectin levels were determined in 55 patients with incident melanoma and 165 age-matched and sex-matched controls. Odds ratios were derived after adjusting for skin type, medical history, sociodemographic, lifestyle, and anthropometric parameters. Among the controls, HOMA-IR correlated positively with BMI (r=0.34; P=0.0001), waist-to-hip ratio (r=0.20; P=0.01) and negatively with serum adiponectin (r=-0.21; P=0.006), whereas the correlation with leptin was essentially null (r=0.09; P=0.27). The mean HOMA-IR was approximately 1.5 times higher in cases than in controls (P=0.05). The established positive association of melanoma with skin type was evident in multiple logistic regression models and so was the association with increasing HOMA-IR quintile (odds ratio for the fifth quintile=3.68; 95% confidence intervals 1.15-11.79, P=0.02). The latter persisted after adjustment for anthropometric variables and adiponectin but was attenuated when leptin was introduced in the model. These findings point to insulin resistance as a potentially independent risk factor for melanoma and need to be confirmed by future larger studies, ideally allowing the control of the directionality of the association. © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins

Simple Evolution of Complex Crystal Species

Cairns-Smith has proposed that life began as structural patterns in clays that self-replicated during cycles of crystal growth and fragmentation. Complex, evolved crystal forms could then have catalyzed the formation of a more advanced genetic material. A crucial weakness of this theory is that it is unclear how complex crystals might arise through Darwinian selection. Here we investigate whether complex crystal patterns could evolve using a model system for crystal growth, DNA tile crystals, that is amenable to both theoretical and experimental inquiry. It was previously shown that in principle, the evolution of crystals assembled from a set of thousands of DNA tiles under very specific environmental conditions could produce arbitrarily complex patterns. Here we show that evolution driven only by the dearth of one monomer type could produce complex crystals from just 12 monomer types. The proposed mechanism of evolution is simple enough to test experimentally and is sufficiently general that it may apply to other DNA tile crystals or even to natural crystals, suggesting that complex crystals could evolve from simple starting materials because of relative differences in concentrations of the materials needed for growth

Safety assessment of a proprietary preparation of a novel Probiotic, Bacillus coagulans, as a food ingredient

It has been demonstrated that some strains of Bacillus coagulans can survive extremes of heat, acidity of the stomach, and bile acids, to which commonly consumed probiotics are susceptible. A toxicological safety assessment was performed on a proprietary preparation of B. coagulans – GanedenBC30™ – a novel probiotic. Seven toxicologic studies were conducted and included: in vitro bacterial reverse mutation assay; in vitro chromosomal aberration assay; micronucleus assay in mice; acute and 90 day subchronic repeated oral toxicity studies were conducted in Wistar Crl:(WI) BR rats; acute eye and skin irritation studies were conducted in rabbits