" The incentives to use both types of cell in comparative studies are high," says Jason Owen-Smith, a sociologist at University of Michigan. "

" If federal funding stops for human embryonic stem cell research, it would have a serious negative impact on adult stem cell research, says Stanford University bioethicist Christopher Scott, one of the paper's co-authors. "

"Once science moves from the laboratory or ice caps into fights over policy and the economy, Mr. Ropeik said, the issues are mainly framed by polarizing figures who tailor their message to people who already strongly support their views."