A study shows that of the one in eight children in several African countries who have asthma, the vast majority are undiagnosed and therefore untreated.
National Geographic's enterprising photographers have helped readers explore and learn about our beautiful world through their images for more than a century. Here is their best work from the past ...
Ms Lacy said: “Without reliable information on where hippos live, and the state of their populations ... Overall crude population estimates vary from 60,000 to 87,000 in southern Africa, so accurate ...
This threshold varies by state and is based on patterns of past vote reporting and expectations about how the vote will report this year. *Maine and Nebraska allow electoral votes to be split.