GOP presidential candidates are touring Iowa ahead of next week's caucuses. The main issue for many voters there is the economy, but another hot topic is emerging: overhauling immigration policies. Iowa's Hispanic population is surging, and Republican candidates are struggling with how best to deal with voter concerns.
Credit Isidore Szczepaniak / Golden Gate Cetacean Research
A harbor porpoise comes up for air near the Golden Gate Bridge. The porpoises are returning to the bay in growing numbers after a 60-year absence.
Credit William Keener / Golden Gate Cetacean Research
A group of harbor porpoises in San Francisco Bay, photographed from the Golden Gate Bridge. Harbor porpoises haven't been seen in the bay since the 1930s. Researchers believe World War II activity may have contributed to their disappearance. The Navy strung a seven-mile underwater net across the mouth of the bay to keep out enemy submarines.
Credit Lauren Sommer / KQED
Bill Keener (left) and Jonathan Stern search for porpoises under the Golden Gate Bridge. Water quality has dramatically improved since the 1970s, which may be bringing the porpoises back.
Something that has been missing from San Francisco Bay since World War II appears to be making a comeback: Harbor porpoises are showing up in growing numbers, and researchers are trying to understand why they're returning.
The walkway across the Golden Gate Bridge is almost always packed with people taking photos. But Bill Keener isn't here for snapshots of the stunning views. He's aiming his massive telephoto lens at a dark shape in the water 200 feet below.
2011 has been a momentous year in the 30-year-old AIDS pandemic.
The big breakthrough was the discovery that antiviral drugs can prevent someone who's infected with HIV from passing the virus to others. It's nearly 100 percent effective. That led President Obama to declare earlier this month that the U.S. will expand HIV treatment in hard-hit countries by 50 percent.