In 2007, when Virginia's Prince William County ordered police to check the immigration status of anyone they had "probable cause" to suspect was in the U.S. unlawfully, the impact was swift at family restaurant Ricos Tacos Moya.
"Suddenly nobody showed up," says Stacey Moya, an employee, and daughter of the owner. "Nobody was around. Not one soul. We would go hours without any customers, any clients. Nothing."
Now to a scientist looking back at the year that's about to end, commentator Adam Frank is an astrophysicist. And in the category of science, he is confident about the headline for 2012.
ADAM FRANK: Something remarkable has happened that may etch this year into history for centuries to come. Twenty-twelve's importance comes not through elections, economic shifts or the new movements in art. No, 2012 may well be remembered for something far more elemental.
This was the year that climate change got real for Americans.
Brain scans using Amyvid dye to highlight beta-amyloid plaques in the brain. Clockwise from top left: a cognitively normal subject; an amyloid-positive patient with Alzheimer's disease; a patient with mild cognitive impairment who progressed to dementia during a study; and a patient with mild cognitive impairment.
It's been a mixed year for Alzheimer's research. Some promising drugs failed to stop or even slow the disease. But researchers also found reasons to think that treatments can work if they just start sooner.
Scientists who study Alzheimer's say they aren't discouraged by the drug failures. "I actually think it was a phenomenal year for research," says Bill Rebeck, a brain scientist at Georgetown University.
Brazilian health officials say an epidemic is taking hold — an outbreak of crack cocaine use nationwide, from the major cities on the coast to places deep in the Amazon.
It's an image at odds with the one Brazil wants to project as the country prepares to host soccer's World Cup in 2014 and the Summer Olympics two years later. But the problem has become too big to ignore.
The Luz district of central Sao Paulo was once grand, with its old train station and opulent buildings. Now, this neighborhood is known as Cracolandia — Crackland.
This is TALK OF THE NATION. I'm Ari Shapiro in Washington. Neal Conan is away. This week, many of us are making year-end charitable donations. There are countless needy people and worthy causes competing for our dollars. So many philanthropists today want proof that an organization actually succeeds at its mission.