Mating is such an arduous and frenzied process for some male marsupials that it literally kills them, according to new Australian-led research.

Scientists had wondered for decades why some species of insect-eating marsupials dropped dead after sex, with speculation including that they died from fighting or to leave more food for their offspring.

A cloud of pollution descended over Beijing at the weekend, shrouding the city and its famous cultural landmarks in a thick haze amid a U.S. warning against physical activity outdoors.

The Beijing Municipal Environmental Monitoring Center said on its website Sunday that pollution levels in the city's six core districts was at 225-245.

When Russia first floated the idea of sending the Olympic flame to the International Space Station (ISS) ahead of next year's Winter Games in Sochi, most people treated it as a joke.

It was February 2011, three years before the launch of the sporting extravaganza, when a top-ranking official in Russia's space agency suggested featuring the ISS in the traditional torch relay ceremony.

Americans James Rothman and Randy Schekman and German-born researcher Thomas Suedhof won the 2013 Nobel Prize in medicine on Monday for discoveries on how proteins and other materials are transported within cells.

The Nobel committee said their research on "vesicle traffic" — the transport system of our cells — helped scientists understand how "cargo is delivered to the right place at the right time" inside cells.

Spain's government said Friday there is a limited risk of a big earthquake shaking the eastern coast after a string of small tremors linked to a vast offshore gas storage plant.

In the past month, some 400 earthquakes have rattled the Gulf of Valencia, where a depleted oil reservoir is being used as a giant gas storage facility. The activity has frightened residents but so far caused no damage.

A landmark agreement aimed at getting the global airline sector to cut carbon emissions by 2020 was approved by the general assembly of the United Nations group that oversees civil aviation.

Delegates from 184 member countries of the International Civil Aviation Organization (ICAO) ratified the agreement on Friday.

A Japanese study is claiming that toxic air pollution from China is to blame for high mercury levels atop the country's beloved Mount Fuji.

The research will likely do little to help simmering hostilities between the Asian giants, a relationship marred by historical animosities and territorial disputes.

U.S. doctors prescribe antibiotics to six out of 10 patients with a sore throat, even though only one infection in 10 is severe enough to merit them, researchers said Thursday.

Overprescribing of antibiotics is dangerous because it contributes to the rise of superbugs that do not respond to treatment.

The man whose research team discovered the Titanic shipwreck is now leading a mission to investigate major faults and underwater volcanoes in the northern and eastern Caribbean to collect information that could help manage natural disasters.

Robert Ballard is overseeing 31 scientists who will set out Friday using remotely operated vehicles to explore the Septentrional and other faults and underwater formations around Puerto Rico, the U.S. Virgin Islands and the eastern Caribbean islands of Dominica and Montserrat.

Braving perilous river rapids in Suriname's rainforest, international scientists found six frogs and 11 fish that are among 60 creatures that may be new species, a tropical ecologist with a U.S.-based conservation group said Thursday.

Trond Larsen, with the nonprofit research and advocacy organization Conservation International, said in a phone interview that the team catalogued creatures and studied freshwater resources during a three-week expedition in pristine forest of southeast Suriname near the border with Brazil.