Running more than four miles a day could be dangerous to your health, according to a study out Tuesday that examined how much exercise is too much.

Researchers focused on 2,400 heart attack survivors and found that the more exercise they did, the less risk they faced of dying from heart disease -- up to a point.

Urging governments to avoid panic and fear, U.N. chief Ban Ki-moon announced plans on Tuesday to step up the global response to the Ebola outbreak and bring it under control.

Ban appointed British physician David Nabarro to be the U.N. coordinator for Ebola, tasked with overseeing the world body's strategy as the death toll from the outbreak topped 1,000.

The only sounds in the abandoned Liberian village were the cries of a little girl, shut up with her mother's body inside the family home, starving and thirsty as she waited for death.

Eventually even the girl -- 12-year-old Fatu Sherrif -- fell silent as she too succumbed to the deadly Ebola virus that is ravaging her country and other parts of west Africa.

Despite fame and fortune, celebrity artists may be more vulnerable to depression than the rest of us, brought low by the same creative qualities that gave them success in the first place, analysts say.

As the world mourned the apparent suicide of comedian Robin Williams on Tuesday, there were many questions about the state of mind of the Oscar-winner once called the funniest man alive.

The Ebola virus has killed 1,013 people and infected another 1,848, latest World Health Organisation data showed.

The fatalities include 52 deaths recorded between August 7-9 in three West African countries at the centre of the epidemic -- Guinea, Liberia and Sierra Leone -- according to the data released late Monday.

Mexican doctors say they have removed a 130-pound (60-kilogram) tumor from the body of a 51-year-old woman who had been unable to leave her home for two years.

Dr. Gilberto Inzulza says a team of surgeons needed four hours to remove the giant tumor from the body of Mercedes Talamantes. Inzulza is chief surgeon at the IMSS public hospital in the northern city of Cabo San Lucas, where Talamantes underwent surgery last month. He hasn't said how much she weighed after the operation.

U.S. scientists on Monday described new advances in making 3D brain-like tissue that can live for more than two months and allows real-time research on brain trauma, disease and recovery.

Scientists discovered they could grow rat neurons in the tissue and then watch how it responded after an injury, incurred by dropping a weight on it, according to the study in the Proceedings of the National Academy of Sciences.

Eight Chinese medical workers who treated Ebola patients have been quarantined in Sierra Leone, as health experts grapple with ethical questions over the use of experimental drugs to combat the killer virus.

Tests on two patients in the west African country of Benin have proved negative for Ebola, the country's health minister said on Monday.

"The samples that were sent to a specialist hospital in Lagos came back negative," Dorothee Akoko Kinde-Gazard told reporters.

The Liberian army has put a third province under quarantine to check the spread of the deadly Ebola virus, President Ellen Johnson Sirleaf announced Monday.

"Lofa county in the north has been quarantined by the army," Sirleaf said after similar measures were taken in the provinces of Boma and Grand Cape Mount.