The Role of Radioactivities in Astrophysics

I present both a history of radioactivity in astrophysics and an introduction to the major applications of radioactive abundances to astronomy

Mate guarding and male mate choice in the chameleon grasshopper Kosciuscola tristis (Prthoptera: Acrididae)

In the wild, male chameleon grasshoppers (Kosciuscola tristis) are frequently observed mounted on the back of females even when not in copula, and will fight off other usurping males. If this behaviour is mate guarding and reflects investment in male mate choice, then we expect males to preferably guard females based on reliable cues of quality. Cues for female quality likely include female size and egg development that together may indicate fecundity. We investigated male mate choice in the field expressed as mate-guarding preference, by comparing size and egg development in guarded and unguarded females. We found no difference between guarded and unguarded females in measures of fecundity or body size. The majority of females sampled did not contain any viable eggs. This finding suggests that male K. tristis indiscriminately guard females in a scramble mating system

Experimental study of the E2 strength distribution in the 12 C and 16O nuclei

The distribution of the E2 strength in 12C and 16O nuclei is investigated by inelastic scattering of 3He. The giant quadrupole resonance is found to be splitted into several states in both nuclei and exhausts 31 % and 37 % of the quadrupole energy weighted sum rule (EWSR) in 12C and 16O respectively.La distribution des transitions quadrupolaires dans les noyaux 12 C et 16O est étudiée par diffusion inélastique de 3He. La résonance quadrupolaire géante présente une structure fine distribuée sur plusieurs niveaux individuels dans les deux noyaux, elle épuise 31 % et 37 % de la règle de somme E2 (EWSR) dans 12C et 16O respectivement