Editor's note: Koko the gorilla, an ambassador for her species famous for learning sign language, has died at the age of 46. To honor Koko's memory, National Geographic is republishing ...

The diversity of weed strains available today can make any pot connoisseur giddy. These flowers vary in flavors and potency, but the visual impact of colorful weed strains never fails to impress.

In Brazil, a few works indicate that shigellosis cases are underestimated, with S. flexneri and S. sonnei strains being the major agents responsible for the shigellosis cases. The present study used ...