Health officials are scrambling to prevent a polio outbreak in Egypt, which has been polio-free since 2004, after the virus was detected at two Cairo sites. Genetic analysis suggests the virus made its way into the country from Pakistan sometime within the past 3 months. So far, no new polio cases have been reported.
For the first time, scientists have shown that we can recognize our own scent based on our unique combination of major histocompatibility complex (MHC) proteins. Animals use similar proteins to choose their mates, and a 1995 study famously concluded that women prefer men who have different MHC genes than themselves. Now, scientists aren't so sure—it seems the brain can pick out its own MHC type, but that's about it. The findings could also explain why the scent of the same perfume varies from person to person.
Researchers have managed to increase the storage density of DNA to a staggering 2.2 petabytes per gram. That's a threefold improvement on previous efforts and means that a single gram of DNA could hold 2.2 million gigabits of information, or about 468,000 DVDs, with 100% accuracy. Don't head out to Best Buy just yet—the technology is now so expensive that it's cost-effective for only data that needs to be stored for more than 600 years.
Researchers investigating the differences between dog and wolf genomes discovered that dogs are much better at digesting starchy foods such as wheat and rice than wolves are. The findings suggest that dogs coevolved with humans and their diet. As humans settled down to farm, the animals that adapted to eat their starchy leftovers had an advantage. So next time you feed Fido a burger, don't forget the bun!
Researchers have ended a nearly yearlong voluntary moratorium on H5N1 bird flu research. They say that governments, scientists, and the public have had enough time to address concerns raised by last year's controversy over two studies that showed how to reengineer the virus to spread between mammals.
It's not just sailors and seals that use starlight to guide their way—dung beetles also use the stars to navigate. They're the first known insects to demonstrate the ability. Male beetles use the Milky Way as a compass to prevent them and their dung balls from rolling around in circles. On cloudy nights, it's harder for them to stay in a straight line.