Talk of the Nation

In his book Concrete Planet, author Robert Courland discusses why the concrete first used by the Romans is more durable than the concrete used in most present day buildings. Plus, mineralogist Peter Stemmerman tells us about his invention, Celitement and why it is greener than Portland cement.

Linguist David Harrison has travelled to remote corners of the world seeking the last speakers of endangered languages. Now, he's using digital tools to to record and revitalize these dying languages. At the AAAS meeting this week, Harrison unveiled 'talking dictionaries' for eight languages.

Duke biologist Sarah Zylinski wants to better understand how cuttlefish see the world. Like their relatives octopus and squid, cuttlefish are master camouflagers--and Zylinski says you can learn something about how they process visual information by testing how they change their skin patterns in relation to different backgrounds.

Two studies in the Archives of Internal Medicine suggest short and long-term exposure to air pollution can increase the risk of stroke and cognitive declines. Study author Jennifer Weuve discusses the results, and why particulate matter and gases like ozone may harm the body.

Writing in the journal Nature, UCSF pediatrician Robert Lustig and colleagues suggest regulating sugar just like alcohol and tobacco--with taxes and age limits, for example--due to what they call the "toxic" effects of too much sweet stuff. Education, they say, is not enough.