MOSCOW, Jan. 1 - Recent turmoil in the news department of REN-TV, Russia's last nationwide television network with independent news programming, has caused concern among media analysts and free-speech advocates in the country. Last July, RTL Group, the broadcasting arm of the Bertelsmann Group, agreed to buy a 30 percent stake in REN-TV from Irena Lesnevskaya, who founded and ran the channel with...