Sixty-nine children in Nigeria have been partially paralysed after weakened viruses from polio vaccines were inadvertently transmitted to people in unvaccinated regions in the north of the country.

Festus Adu, director of the WHO's polio laboratory in Ibadan, Nigeria, told SciDev.Net that this polio outbreak is only appearing in areas where people are refusing to be vaccinated or where there is not enough oral polio vaccine.

The prestigious 10 million Swedish crown ($1.54 million) prize recognized Mario Capecchi, Martin Evans and Oliver Smithies for helping discover "the roles of numerous genes in embryonic development, adult physiology, aging and disease".

CHICAGO (Reuters) - A sheriff's deputy shot and killed six young people in the northern Wisconsin town of Crandon before being killed himself after a manhunt, a local TV station reported on Sunday, quoting police and witnesses.

The Forest County Sheriff's Department said seven people were dead, including the deputy, Tyler Peterson, according to a report on the WJFW-TV Web site.

The sheriff's department would not confirm details.

LONDON (Reuters) - The world moved into "ecological overdraft" on Saturday, the point at which human consumption exceeds the ability of the earth to sustain it in any year and goes into the red, the New Economics Foundation think-tank said.

Ecological Debt Day this year is three days earlier than in 2006 which itself was three days earlier than in 2005. NEF said the date had moved steadily backwards every year since humanity began living beyond its environmental means in the 1980s.

"As the world creeps closer to irreversible global warming and goes deeper into ecological debt, why on earth, say, would the UK export 20 tonnes of mineral water to Australia and then re-import 21 tonnes," said NEF director Andrew Simms.

CHICAGO (Reuters) - Sam's Club is pulling frozen hamburgers made by agribusiness giant Cargill Inc. from its stores shelves across the United States as Minnesota health officials investigate four cases of E. coli associated with the burgers.

In a statement dated Friday, Sam's Club owner Wal-Mart Stores Inc said the warehouse club is removing the American Chef's Selection Angus Beef patties from U.S. locations and giving refunds to customers who already purchased the burgers.

All four cases of E. coli being investigated occurred in children, the Minnesota Department of Health said in a statement. The cases are associated with eating ground beef patties purchased from Sam's Club stores in late August and September.

Sam's Club customers should return or destroy any American Chef's Selection Angus Beef purchased from Sam's Club since August 26, the department of health said.

WHITE PLAINS, New York (Reuters) - Athletics superstar Marion Jones told a judge on Friday she would plead guilty to two felonies in connection with a steroid investigation, a decision that could cost her the five medals she won in the 2000 Sydney Olympics.

Earlier on Friday federal law enforcement sources said she would likely plead guilty to lying to federal investigators about her steroid use before the 2000 Olympics and to lying to federal agents about a separate check fraud case.

Jones would become the first athlete convicted in connection with a probe into the San Francisco-area laboratory BALCO, the center of a doping scandal that has tarnished the reputations of leading athletes in baseball, football and athletics.

BALTIMORE - Gas-electric hybrid vehicles, the status symbol for the environmentally conscientious, are coming under attack from a constituency that doesn't drive: the blind.  Because hybrids make virtually no noise at slower speeds when they run solely on electric power, blind people say they pose a hazard to those who rely on their ears to determine whether it's safe to cross the street or walk through a parking lot.