Tokyo on Thursday closed most of Yoyogi Park, a popular green spot in the Japanese metropolis, after dengue-carrying mosquitoes were found there, an official said.

The outbreak is the first in 70 years in Japan and has so far infected 55 people, including a young model who has posed for Japanese Playboy and had been sent to the park for a photo shoot.

Nearly three billion people risk ill health and early death merely from breathing the air in their homes that is polluted by fires made for cooking and heating, researchers said.

Some 40 percent of the world's population, mainly in Africa and Asia, use wood, charcoal or coal to cook, warm and light their homes, according to a review published by The Lancet Respiratory Medicine journal.

Women fighting cancer in one breast don't benefit from having both breasts removed, according to new research out Tuesday, that found long-term survival was equivalent after targeted surgery plus radiation.

Hollywood star Angelina Jolie famously announced last year she had a double mastectomy to reduce her risk of one day developing breast cancer, because she has a genetic mutation that substantially increases breast cancer risk.

International medical agency Medecins sans Frontieres said the world was "losing the battle" to contain Ebola as the United Nations warned of severe food shortages in the hardest-hit countries.

MSF told a U.N. briefing in New York that world leaders were failing to address the epidemic and called for an urgent global biological disaster response to get aid and personnel to west Africa.

The founder of a Los Angeles-based nonprofit that provides free music lessons to low-income students from gang-ridden neighborhoods began to notice several years ago a hopeful sign: Kids were graduating high school and heading off to UCLA, Tulane and other big universities.

That's when Margaret Martin asked how the children in the Harmony Project were beating the odds.

International medical agency Medecins Sans Frontieres said Tuesday the world was "losing the battle" to contain Ebola and called for a global biological disaster response to get aid and personnel to west Africa.

"Six months into the worst Ebola epidemic in history, the world is losing the battle to contain it. Leaders are failing to come to grips with this transnational threat," MSF international president Joanne Liu told a U.N. briefing in New York. 

An outbreak of the Ebola virus in the Democratic Republic of Congo has killed 31 people and the epidemic remains contained within the country's northwest, the World Health Organization (WHO) said Tuesday.

"There are now 31 deaths," Eugene Kambambi, the WHO's head of communication in DR Congo, told Agence France Presse adding that the epidemic remains ringfenced in an area around 800 kilometers (500 miles) north of Kinshasa. The WHO had previously given a death toll of 13 for the country.

Americans' eating habits have improved — except among the poor, evidence of a widening wealth gap when it comes to diet. Yet even among wealthier adults, food choices remain far from ideal, a 12-year study found.

On an index of healthy eating where a perfect score is 110, U.S. adults averaged just 40 points in 1999-2000, climbing steadily to 47 points in 2009-10, the study found.

Nurses at Liberia's largest hospital went on strike on Monday, demanding better pay and equipment to protect them against a deadly Ebola epidemic which has killed hundreds in the west African nation.

John Tugbeh, spokesman for the strikers at Monrovia's John F Kennedy hospital, said the nurses would not return to work until they are supplied with "personal protective equipment (PPEs)", the hazmat-style suits which guard against infectious diseases.

Could action-packed TV fare make you fat? That's the implication of a new study that found people snacked more watching fast-paced television than viewing a more leisurely-paced talk show.

Cornell University researchers randomly assigned almost 100 undergraduates to watch one of three 20-minute sessions featuring: "The Island," a 2005 sci-fi thriller starring Scarlett Johansson and Ewan McGregor; that same movie but without the sound; or the "Charlie Rose" show, a public television interview program. The students were all provided generous amounts of cookies, M&M candies, carrots and grapes.