Author Dan Buettner has traveled the globe visiting "blue zones," where people tend to live longer and lead healthier lives. Cheryl Tiegs/National Geographic Books hide caption

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It's important to talk to your vet about any changes in your dog's behavior or diet, says veterinarian Nicholas Dodman. hide caption

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Louis Zamperini peers over the hatch nose of his aircraft in 1943. Later that year, a crash involving a B-24 bomber similar to this one would land the former Olympian in a Japanese prison camp. AP hide caption

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English novelist Jane Austen is known for her polished prose, but her handwritten manuscripts reveal some telling grammatical errors. Hulton Archive/Getty Images hide caption

itoggle caption Hulton Archive/Getty Images