Toilets, as most of us know them, haven't changed much since the 1800s--they use a lot of water, and require an infrastructure that many communities can't afford. Ira Flatow and guests look at the problem of access to sanitation, and how engineers are making toilets better.

At a recent conference, a Dutch scientist said he'd made bird flu virus highly contagious between ferrets — the animal model used to study human flu infection. Just five mutations did the trick. Security experts fear publishing the work could spur development of new weapons.

Scientists are worried about the deadly bird flu called H5N1 which sometimes infects people. It's never acquired the ability to transmit easily between humans, but researchers would like to know if that could happen. Recently, they've essentially been altering the genes of H5N1 to make the virus spread more easily between lab animals — raising concerns about biosafety and how this research is regulated.

Each year more than 60,000 babies are born weighing less than 3.3 pounds. As scientists learn more about how brain injuries occur among these very premature infants, it could point the way to possible prevention and repair strategies.

To find out why some livers retain fat during cooking, scientists analyzed liver proteins in ducks. They found that if you reduce the time you overfeed the ducks, you're get livers that lose less fat during cooking.

Energy Secretary Steven Chu will face scrutiny on Capitol Hill Thursday over loans to the failed solar firm. But the government has a long history of subsidizing many kinds of energy, from coal to oil to wind. Still, different sectors disagree on whether tax deductions should be considered a subsidy.

Public health officials say the evidence is solid that fluoridated drinking water helps protect teeth. But that hasn't stopped opponents from lobbying local governments against the practice.