8 research outputs found
Burkhardt-Cottingham sum rule and forward spin polarizabilities in Heavy Baryon Chiral Perturbation Theory
We study spin-dependent sum rules for forward virtual Compton
scattering(VVCS) off the nucleon in heavy baryon chiral perturbation theory at
order . 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 can be accessed, at small and
intermediate 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
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
resonance region at 0.35 (GeV/c). 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 multipoles, mainly
contributing to the non-resonant background. The beam-helicity asymmetry in
both channels ( and ) 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
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
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