Ripped From the Journals: The Biggest Discoveries of the Week

, October 6 PNAS was a grab bag of oddball findings this week. In one study, archaeologists argued that hoards of coins buried by ancient Romans not only serve as a measure for societal instability, they also provide clues about population changes in the republic. Since citizens presumably planned to dig up their hidden coins again in order to spend them, the researchers say, those hoards left behind indicate people who died or fled. In another study, a medical research team stirred together a bunch of buzzwords--nanotechnology, gene therapy, and stem cells--and found a promising way to aid potential stem cell therapies. While stem cells can rapidly grow into any kind of new tissue, they aren’t always able to encourage new blood vessels to grow so that the tissue stays alive. The team used nanoparticles to deliver a key gene, which spurs the growth of blood vessels, to the developing ...