DURHAM — When University of New Hampshire professor Blake Gumprecht read a recent New York Times article about kayaking down the Los Angeles River, the passages struck him as familiar. Too familiar. The story wasn’t just similar to his 1999 book, “The Los Angeles River: Its Life, Death, and Possible Rebirth,” Gumprecht says, it was, in places, almost identical to pages he had written. So the UNH assistant geography professor fired off an e-mail to Times editor Renee Murawski, alleging reporter Charlie LeDuff had lifted portions of his book for the newspaper article. “What is most striking to me is...