Quentin Cooper presents his weekly digest of science in and behind the headlines. This week, as polar scientists meet in Oslo to present their findings from International Polar Year, we hear from two of them about the potentially fragile ecosystems on land and in the sea. Geraint Tarling from the British Antarctic Survey describes the differences between the marine food chains in Arctic and Antarctic waters and the importance of krill, perhaps even to offset climate change. And his colleague Pete Convey outlines the threat posed by introduced alien species on the fragile land communities of Antarctica and its islands. Britain's horse chetnuts are under threat! The iconic conker trees are suffering from what's called 'bleeding canker' as their leaves turn prematurely brown and die, under attack from the Horse Chestnut leaf miner catterpillar. Darren Evans of Hull University is looking for volunteers to monitor the spread of the disease. As the World Cup gets underway in South Africa, England fans are only too well aware that their team has a less-than-perfect record for penalty shoot-outs. So what advice can Exeter University psychologist Greg Wood give them? There's a new term for an old science: molecular gastronomy - cooking to most of us! Prior to their double act at the Cheltenhan Science Festival, Quentin hears from chemist and food science writer Harold McGee and culinary wizard Heston Blumenthal about the science behind their success.