Scientists have been able to restore some cellular activity in pigs that were slaughtered hours earlier, according to a study published on Wednesday in the journal Nature. Though the brains did not regain enough activity to renew actual consciousness, blood vessels started functioning and some of them regained metabolic activity. Before now, “we had clear lines between ‘this is alive’ and ‘this is dead,’” Nita Farahany, a bioethicist and law professor at Duke University, told The New York Times. “How do we now think about this middle category of ‘partly alive’? We didn’t think it could exist.” The study raises questions about whether it might be possible to restore function to a person who has suffered extensive brain injury. Jonathan Moreno, a bioethicist at the University of Pennsylvania, told the Times: “If ever there was an issue that merited big public deliberation on the ethics of science and medicine, this is one.”