The erosion of frozen SO 2 due to bombardment by both light and heavy ions (He and F) was measured for bombarding energies of 0.08 to 1.3 MeV/amu. The number of SOp molecules ejected from the target per incident ion (i.e.• the sputtering yield) was 50 for 1.5 MeV He ions and ?300 for 6 MeV F ions. Ion bombardment followed by heating produced an oxygen/sulfur residue which was much more stable a...

The number of laboratories using the free living nematode C. elegans is rapidly growing. The popularity of this biological model is attributed to a rapid generation time and short life span, easy and inexpensive maintenance, fully sequenced genome, and array of RNAi resources and mutant animals. Additionally, analysis of the C. elegans genome revealed a great similarity between worms and higher...

Geochronological evidence for and against a Late Heavy Bombardment (LHB) spike in impact rates on the Moon and meteorite parent bodies is re-examined. In particular, we find that the sampling of impact melts on the Moon is strongly biased against older examples, possibly due to preferential surface deposition of such melts and/or blanketing and burial by basin ejecta (arguments that the bias mi...