Gravity “steps” at Mt. Etna volcano (Italy). Instrumental effects or evidences of earthquake-triggered magma density changes?

On two occasions, sudden gravity changes occurred simultaneously at two summit Etna’s stations, during local low-magnitude earthquakes. A systematic coupling between earthquakes inducing comparable maximum acceleration and displacement at the observation points and gravity steps is missing, implying (a) the non-instrumental nature of the steps and (b) the need for particular underlying conditions for the triggering mechanism(s) to activate. We review some of the volcanological processes that could induce fast underground mass redistributions, resulting in gravity changes at the surface. These processes involve bubbles and crystals present in the magma and require particular conditions in order to be effective as mass-redistributing processes. The gravity steps could be a geophysical evidence of the dynamical stress transfer between tectonic and magmatic systems at a local scale. Given the implications that these transfers may have on the volcanic activity, routine volcano monitoring should include the observation of fast gravity changes

Organ donation in France: legislation, epidemiology and ethical comments

The Bioethics Laws revised in 2004 have defined rules concerning organ donation and transplantation. They have also permitted the creation of the French Biomedicine Agency which guarantees the right of enforcement. In France there are three situations in which organs may be harvested: from cadaveric donors, from living donors and, since 2005, from non heart beating donors.Organ harvesting from cadaveric donors is permissible if the deceased did not make known his refusal during his lifetime (this may be recorded in the national registry set up for this purpose). The rule of presumed consent also applies in the case of organs taken after cardiac arrest. With regard to organ harvesting from living persons, a panel of experts is required to give approval. The recipient\u27s spouse, brothers or sisters, sons or daughters, grandparents, uncles or aunts and first cousins may be authorised to donate organs, as well as the spouse of the recipient\u27s father or mother. The donor may be any person who provides proof of having lived with the recipient for at least two years. Some ethical questions will need to be resolved; for example the relevance of maintaining the EEG for brain death diagnosis, enforcement of the law on presumed consent, the real nature of the will of living donors and the definition of death

Prélèvements d’organes sur donneurs décédés après arrêt cardiaque

Points essentielsLes prélèvements sur personne décédée après arrêt cardiaque sont autorisés en France depuis 2005 (décret du 2 août 2005 : art R.1232-4-1,2 et 3 du code de la santé publique). Récemment, à l’échelle internationale, 4 types de situations pouvant conduire à un prélèvement sur personne décédée après arrêt cardiaque ont été identifiés dans une classification dite de « Maastricht » qui décrit les donneurs potentiels. En France, les prélèvements sur les donneurs de classe III (arrêt des soins) sont exclus. L’émergence de cette nouvelle technique soulève des réflexions notamment d’ordre éthique, concernant la définition même de la mort, la place de cette pratique par rapport à des techniques de réanimation nouvelles, le vécu des familles et des équipes. Elle apporte tout de même un élément de solution à la pénurie d’organes manifeste, avec des résultats de suivis des greffés très encourageants selon les publications étrangères appliquant ces techniques. L’ensemble du dispositif est d’autre part réglementé et sous la tutelle de l’Agence de la biomédecine qui en assure le bon fonctionnement technique et le respect des règles éthiques

Selection rules in three-body B decay from factorization

Extending the dynamics underlying the factorization calculation of two-body decays, we propose simple selection rules for nonresonant three-body B decays. We predict, for instance, that in the Dalitz plot of B^0-->D^0-bar\pi^+\pi^-, practically no events should be found in the corner of E(\pi^+) < \Lambda_{QCD} as compared with the corner of E(\pi^-) < \Lambda_{QCD}. We also predict that there should be very few three-body decay events with a soft meson resonance and two energetic mesons or meson resonances. The selection rules are quite different from the soft pion theorem, since they apply to different kinematical regions. For B^0 -->D^0-bar\pi^+\pi^-, the latter predicts that the decay matrix element vanishes in the zero-four-momentum limit of \pi^+ instead of \pi^-. Since this marked difference from the soft pion theorem is directly related to the issue of short-distance QCD dominance in the FSI of two-body B decays, experimental test of the selection rules will shed light on strong interaction dynamics of B decay.Comment: 12 pages in REVTEX including 3 eps figure

Electromagnetic form factors in the J/\psi mass region: The case in favor of additional resonances

Using the results of our recent analysis of e^+e^- annihilation, we plot the curves for the diagonal and transition form factors of light hadrons in the time-like region up to the production threshold of an open charm quantum number. The comparison with existing data on the decays of J/\psi into such hadrons shows that some new resonance structures may be present in the mass range between 2 GeVand the J/\psi mass. Searching them may help in a better understanding of the mass spectrum in both the simple and a more sophisticated quark models, and in revealing the details of the three-gluon mechanism of the OZI rule breaking in K\bar K channel.Comment: Formulas are added, typo is corrected, the text is rearranged. Replaced to match the version accepted in Phys Rev

Possible large phase in psi(2S) -> 1-0- Decays

The strong and the electromagnetic amplitudes are analyzed on the basis of the measurements of J/psi, psi(2S) -> 1-0- in e+e- experiments. The currently available experimental information is revised with inclusion of the contribution from e+e- -> gamma * -> 1-0- . The study shows that a large phase around minus 90 degree between the strong and the electromagnetic amplitudes could not be ruled out by the experimental data for psi(2S).Comment: 4 page

On the Mixing of the Scalar Mesons f0(1370)f_0(1370), f0(1500)f_0(1500) and f0(1710)f_0(1710)

Based on a $3\times3$ mass matrix describing the mixing of the scalar states $f_0(1370)$, $f_0(1500)$ and $f_0(1710)$, the hadronic decays of the three states are investigated. Taking into account the two possible assumptions concerning the mass level order of the bare states $|N>=|u\bar{u}+d\bar{d}>/\sqrt{2}$, $|S>=|s\bar{s}>$ and $|G>=|gg>$ in the scalar sector, $M_G > M_S > M_N$ and $M_G > M_N > M_S$, we obtain the glueball-quarkonia content of the three states by solving the unlinear equations. Some predictions about the decays of the three states in two cases are presented, which can provide a stringent consistency check of the two assumptions.Comment: revtex 10 pages, 1 eps figur