Split more or less neatly into pairs, the four short Oscar-nominated documentaries prove again that the old style-versus-substance debate is never sillier than when it's applied to non-fiction film. That is to say, if the collection includes works about children orphaned by AIDS in China and extreme poverty in Guatemala, what does it matter that, of the remaining films about privileged American artists, one ("Two Hands," about pianist Leon Fleisher) is extremely well made and the other ("Rehearsing a Dream," about high-school arts grant winners) isn't? PSA-style narration by Edward James Olmos doesn't much hinder "Recycled Life," whose portrait of resilient bottom-feeders at the forty-acre Guatemala City garbage dump includes images of small children in cardboard-box cribs and interviews with the city's head of social services. ("I believe the dump is a reflection of the entire state of Guatemala.") And "The Blood of Yingzhou District" puts no stylistic obstacles in the way of its powerful lament for orphans who are outcasts in their villages because of widespread fear of a disease that some can't even name, much less understand. Director Ruby Yang, who's also co-creator of the China AIDS Media Project (CAMP), never once pushes for the sort of easy uplift that Oscar-seeking documentarians tend to offer. If there's any justice, the award will be hers, followed by greater attention to her cause.