* University of Arizona biologists rule out the controversial theory that an oral polio vaccine was responsible for passing the AIDS virus to humans.
* Conservation experts at the Louvre Museum in Paris are baffled to find Leonardo da Vinci’s Mona Lisa deteriorating at an accelerated pace.
* No sperm necessary: By combining genetically altered cells, Japanese scientists create a healthy baby mouse using only female DNA.
* Foreign scientists, especially Asians, are catching up with Americans in doctoral degrees and journal publications, the NSF reports.
* Chinese glacial deposits show that three of the oldest and coldest ice ages in Earth’s history date from 600 to 750 million years ago.
* Fresh evidence of early life: Microscopic tubes in 3.5-billion-year-old basaltic rocks appear to be impressions of ancient bacteria.
* A South African cave yields 75,000-year-old pieces of shell-bead jewelry, the earliest evidence of symbolic thinking by humans.
* Astronomers detect a distant planet by measuring how its gravity bends light. The Jupiter-size world is 17,000 light-years away.
