On this weeks Pan-Continental Naked Scientists we bring you the latest science news from the AAAS conference in Boston. We hear about why cholesterol-lowering drugs are good for us but bad for bacteria, see the map that shows mankind's effect on the oceans and discover the surprisingly complex science of sand castles. Also in this week's show, we look into the future for organ transplants - how bone marrow grafts could make rejection a thing of the past, keeping organs alive outside the body and how we can grow a beating heart in the lab! Plus, in Kitchen Science, we find out how to prove that blood circulates around the body! Listen to this ShowIf you want to discuss this show, or ask a question, this is the place to do it.