Findings, detailed in Thursday's issue of the journal Nature, support the idea that the abundance of heavy elements in stars decreases with time and could help solve the cosmological lithium problem, a riddle that has been puzzling astronomers for years.

Lithium is one of the few elements thought to have been produced during the Big Bang, but when astronomers compare the amounts of lithium contained within the atmospheres of the very old stars in our Milky Way galaxy, they find their predictions are higher by a factor of 2 to 3.

For the solution:
http://www.msnbc.msn.com/id/14271064/

It would be interesting to detect the Li-6/Li-7 ratio in Li-rich and Li-depleted stars. Li-6 (7.5% of terrestrial abundance) has a huge thermal neutron capture cross-section, then fissions. Li-7 requires a high density of high energy neutrons. One would naively expect the light isotope to deplete faster.

Good point.