Description of Trichodorus variabilis n. sp. (Nemata : Diphterophoroidea) from Greece

Description est donnée de #Trichodorus variabilis n. sp. Cette nouvelle espèce a été trouvée au cours de récoltes de #Longidoridae à Kato Souli, Marathon, Grèce, dans la rhizosphère d'artichaut. Le mâle est caractérisé par la présence de deux papilles cervicales médioventrales, postérieures à la base du stylet, la position du pore excréteur, variable par rapport aux papilles cervicales, la forme du spicule possédant un manubrium élargi joint graduellement à un calomus élancé, de même épaisseur ; la femelle est caractérisée par la forme du vagin en tonneau, la sclérotisation vaginale triangulaire et de petite taille, et la présence d'une paire de pores latéraux, post-advulaires. #Trichodorus variabilis n. sp. est proche de #T. giennensis Decraemer et al., 1993 et #T. sparsus$ Szczygiel, 1968. (Résumé d'auteur

Theoretical study of elastic electron scattering off stable and exotic nuclei

Results for elastic electron scattering by nuclei, calculated with charge densities of Skyrme forces and covariant effective Lagrangians that accurately describe nuclear ground states, are compared against experiment in stable isotopes. Dirac partial-wave calculations are performed with an adapted version of the ELSEPA package. Motivated by the fact that studies of electron scattering off exotic nuclei are intended in future facilities in the commissioned GSI and RIKEN upgrades, we survey the theoretical predictions from neutron-deficient to neutron-rich isotopes in the tin and calcium isotopic chains. The charge densities of a covariant interaction that describes the low-energy electromagnetic structure of the nucleon within the Lagrangian of the theory are used to this end. The study is restricted to medium and heavy mass nuclei because the charge densities are computed in mean field approach. Since the experimental analysis of scattering data commonly involves parameterized charge densities, as a surrogate exercise for the yet unexplored exotic nuclei, we fit our calculated mean field densities with Helm model distributions. This procedure turns out to be helpful to study the neutron-number variation of the scattering observables and allows us to identify correlations of potential interest among some of these observables within the isotopic chains.Comment: 18 pages, 14 figures, revtex4; modifications in text and figure