8 research outputs found

    Burkhardt-Cottingham sum rule and forward spin polarizabilities in Heavy Baryon Chiral Perturbation Theory

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    We study spin-dependent sum rules for forward virtual Compton scattering(VVCS) off the nucleon in heavy baryon chiral perturbation theory at order O(p4)O(p^4). We show how these sum rules can be evaluated from low energy expansions (in the virtual photon energy) of the forward VVCS amplitudes. We study in particular the Burkhardt -Cottingham sum rule in HBChPT and higher terms in the low energy expansion, which can be related to the generalized forward spin polarizabilities of the nucleon. The dependence of these observables on the photon virtuality Q2Q^2 can be accessed, at small and intermediate Q2Q^2 values, from existing and forthcoming data at Jefferson Lab.Comment: 16 pages,4 fig

    Beam-helicity asymmetry in photon and pion electroproduction in the Delta(1232) resonance region at Q^2= 0.35 (GeV/c)^2

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    The beam-helicity asymmetry has been measured simultaneously for the reactions (e p \to e p \gamma) and (e p \to e p \pi^0) in the Δ(1232)\Delta (1232) resonance region at Q2=Q^2= 0.35 (GeV/c)2^2. The experiment was performed at MAMI with a longitudinally polarized beam and an out-of-plane detection of the proton. The results are compared with calculations based on Dispersion Relations for virtual Compton scattering and with the MAID model for pion electroproduction. There is an overall good agreement between experiment and theoretical calculations. The remaining discrepancies may be ascribed to an imperfect parametrization of some γ()NπN\gamma^{(*)} N \to \pi N multipoles, mainly contributing to the non-resonant background. The beam-helicity asymmetry in both channels (γ\gamma and π0\pi^0) shows a good sensitivity to these multipoles and should allow future improvement in their parametrization.Comment: 7 pages, 8 figures, version to appear in EPJ

    Gastrointestinal endoscopy devices and the European Union Medical Device Regulation: European Society of Gastrointestinal Endoscopy (ESGE) Position Statement

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    Gastrointestinal endoscopy is largely dependent on medical devices. The European Union (EU) has recently introduced stricter rules and regulations for the approval of medical devices. This has consequences both for endoscopists and for patients. The new regulations increase the need for clinical trials and observational studies for new and current devices used in endoscopy to ensure clinical benefit and reduce patient harm. European endoscopy environments should facilitate industry-sponsored clinical trials and registry studies to meet the demand for robust data on endoscopic devices as required in the new legislation. The European Society of Gastrointestinal Endoscopy (ESGE) will play an active role in the establishment of the new system.The EU is establishing independent expert panels for device regulation in gastroenterology and hepatology, including endoscopy, that are charged with assessing the requirements for device testing. The ESGE encourages endoscopists with expertise in the technical and clinical performance of endoscopy devices to apply for expert panel membership. The ESGE has provided information for interested endoscopists on the ESGE website. Private European companies called "notified bodies" are entitled to conduct device approval for the EU. The ESGE will actively engage with these notified bodies for topics related to the new endoscopy device approval process to ensure continued access to high quality endoscopy devices for endoscopists in Europe

    Targeting PI3K in neuroblastoma

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    This work employs pharmacological targeting of phosphoinositide 3-kinases (PI3K) in selected neuroblastoma (NB) tumors with the inhibitor AS605240, which has been shown to express low toxicity and relative specificity for the PI3K species
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