Australia's koala population has been hit hard by two rapidly spreading diseases: chlamydia (a sexually transmitted infection) and a retrovirus similar to HIV. Scientists are working to develop vaccines, while lay citizens help care for sick koalas. Biologists say the epidemics, combined with other threats like habitat loss, pose a serious threat to the species. For more global science stories, visit: http://www.world-science.org/ Funding for NOVA is provided by David H. Koch, the Corporation for Public Broadcasting, and PBS viewers.

In this interview with The World's Marco Werman, NOVA Producer Miles O'Brien describes how surveillance footage played a key role in cracking the case of the Boston Marathon bombings. But as O’Brien discovered in the course of reporting the NOVA special “Manhunt—Boston Bombers,” other cities, especially New York City, have surveillance camera networks that are far more advanced than Boston’s hodgepodge system. O’Brien recounts just how powerful those systems are and what that may portend for privacy in the future. NOVA is produced by WGBH in Boston. National corporate funding for NOVA is provided by The Boeing Company. Major funding for NOVA is provided by the David H. Koch Fund for Science, the Corporation for Public Broadcasting, and PBS viewers.

The residents of Australia's Northern Territory share their land with one of the deadliest predators on the planet—the saltwater crocodile. Getting humans and these fearsome reptiles to coexist isn't easy. But a government program called "Be Crocwise" is doing its best to keep the peace. For more global science stories, visit: http://www.world-science.org/ NOVA is produced by WGBH in Boston. National corporate funding for NOVA is provided by The Boeing Company. Major funding for NOVA is provided by David H. Koch, the Corporation for Public Broadcasting, and PBS viewers.

An Oxford University researcher will soon test whether applying an electric current to part of the brain can help children learn math—an effect previously demonstrated in adults. Parents are already lining up for access to the device. But is the technique safe? And is this an ethical way to improve a child’s performance in school? For more global environmental stories, visit: http://www.pbs.org/wgbh/nova/earth/ http://www.theworld.org/category/topics/environment/ NOVA is produced by WGBH in Boston. National corporate funding for NOVA is provided by The Boeing Company. Major funding for NOVA is provided by the David H. Koch Fund for Science, the Corporation for Public Broadcasting, and PBS viewers.

What makes a dog bold or shy, eager or sullen? The Veterinary University of Vienna's Clever Dog Lab aims to find out with the help of some 600 Austrian dogs that owners volunteer for experiments. The results could improve the training and selection of dogs that serve society, from helping the disabled to assisting the police. For more global science stories, visit: http://www.world-science.org/ NOVA is produced by WGBH in Boston. Funding for NOVA scienceNOW is provided by the National Science Foundation, the Alfred P. Sloan Foundation, and PBS viewers. National corporate funding for NOVA is provided by The Boeing Company. Major funding for NOVA is provided by the David H. Koch Fund for Science, the Corporation for Public Broadcasting, and PBS viewers.

The last place you'd expect to find a new treasure is where everyone has been looking for centuries. Yet in Europe, home to history's greatest taxonomists, professional scientists and amateurs are scouring the countryside for new species—and finding them at an astonishing rate. Funding for NOVA is provided by David H. Koch, the Corporation for Public Broadcasting, and PBS viewers.

People around the world spend an estimated 3 billion hours playing computer games every week. That might seem like a colossal waste of time, but scientists are starting to harness some of that effort to solve vexing problems in biology. Take, for example, a game developed by a pair of scientists in Canada. This podcast was produced by Sam Eaton for NOVA and PRI's "The World." For more global environmental stories, visit: http://www.pbs.org/wgbh/nova/earth/ http://www.theworld.org/category/topics/environment/ Funding for NOVA is provided by David H. Koch, the Corporation for Public Broadcasting, and PBS viewers.

British scientists have developed a genetic test for a disorder that causes people to emit an unusual body odor: The gene causes sufferers to smell like rotten fish. For those who have been ostracized—shunned by friends and unable to hold jobs because they are perceived as unhygienic—the test offers some solace. But one patient says the genetic discovery has not changed his life as much as he had hoped for. This podcast was produced by Sam Eaton for NOVA and PRI's "The World." National corporate funding for NOVA is provided by The Boeing Company. Major funding for NOVA is provided by David H. Koch, the Corporation for Public Broadcasting, and PBS viewers.