Neutron Density Distributions of Neutron-Rich Nuclei Studied with the Isobaric Yield Ratio Difference

The isobaric yield ratio difference (IBD) between two reactions of similar experimental setups is found to be sensitive to nuclear density differences between projectiles. In this article, the IBD probe is used to study the density variation in neutron-rich $^{48}$Ca. By adjusting diffuseness in the neutron density distribution, three different neutron density distributions of $^{48}$Ca are obtained. The yields of fragments in the 80$A$ MeV $^{40, 48}$Ca + $^{12}$C reactions are calculated by using a modified statistical abrasion-ablation model. It is found that the IBD results obtained from the prefragments are sensitive to the density distribution of the projectile, while the IBD results from the final fragments are less sensitive to the density distribution of the projectile.Comment: 3 figure

Exposure to crude microcystins via intraperitoneal injection, but not oral gavage, causes hepatotoxicity in ducks

Recently, large-scale cyanobacterial blooms have occurred in fishponds near the suburbs of Xinxiang City in China. The present study aimed to identify the cyanobacterial blooms in the fishpond and evaluate their toxicity on ducks via intraperitoneal injection or oral exposure (gavage) of crude microcystins obtained from the scum of cyanobacterial bloom. The results of the acute toxicity tests showed that intraperitoneal injection of crude microcystin solution caused hepatotoxicity in ducks and ducklings, but oral exposure failed to do so. This result confirms the observation of no duck intoxication by a natural way of oral exposure in the fishponds during the periods of blooms. In addition, subchronic exposure of microcystins by intraperitoneal injection significantly inhibited the growth of ducklings.Keywords: Microcystis bloom, microcystins, duck, toxicit