During the peak of the polio epidemic in the U.S., some hospital wards even had large, room-like iron lungs where multiple children lived. Courtesy of Boston Children's Hospital Archive hide caption

President Obama and Republican presidential candidate Mitt Romney first debated Medicare on Oct. 3. Saul Loeb/AFP/Getty Images hide caption

New research suggests that success in life may be determined by ancestors from hundreds of years ago. The research finds that your chance of making it into the elite is the same in the United States as it is in South America, no matter when you were born. Dan Kitwood/Getty Images hide caption

Home health aide trainees Marisol Maldonaldo (center) and Nancy Brown (right), shown here with assistant instructor Miguelina Sosa, are studying to join one of the nation's fastest growing yet also worst paid sectors of the workforce. Jennifer Ludden/NPR hide caption

K'Naan's new album is titled Country, God or the Girl. Courtesy of the artist hide caption