The negligence of local authorities and a failure to learn from past disasters were a prime factor behind the flooding that claimed at least 171 lives in southern Russia, the press said on Monday.

With officials keen to blame freak rains for the disaster, both pro-government and opposition newspapers showed rare unanimity in saying the authorities had badly failed local inhabitants in the worst-hit town of Krymsk.

More than 85 percent of reefs in Asia's "Coral Triangle" are directly threatened by human activities such as coastal development, pollution, and overfishing, a new report warned Monday.

Launched at the International Coral Reef Symposium in Cairns, it said the threat was substantially more than the global average of 60 percent and urged greater efforts to reduce destructive fishing and run-off from land.

A nuclear reactor in western Japan began full operations Monday, the first restart since the country shut down its atomic stations in the wake of last year's crisis at the Fukushima Daiichi plant.

Kansai Electric Power Co. (KEPCO), operator of the Oi power plant in the nation's industrial heartland, said its Unit No. 3 had come back to full capacity early Monday after the reactor was switched on earlier this month.

Two scientific papers published Sunday disproved a controversial claim made by NASA-funded scientists in 2010 that a new form of bacterial life had been discovered that could thrive on arsenic.

"Contrary to an original report, the new research clearly shows that the bacterium, GFAJ-1, cannot substitute arsenic for phosphorus to survive," said a statement by the U.S. journal Science, a prestigious, peer-reviewed magazine.

The Defense Department's research arm will seek proposals next month for solutions to technology hurdles in super high-speed flight with a goal of testing a full-scale hypersonic X-plane in four years.

The Defense Advanced Research Projects Agency said Friday it will host a so-called Proposers' Day on Aug. 14 to lay out technical areas for which proposals are being sought.

A solar-powered plane landed in Spain Saturday on its way back home after breaking a record with the first intercontinental flight by an aircraft run on the sun's energy, organizers said.

Swiss adventurer Bertrand Piccard, 54, piloted the experimental plane Solar Impulse on the 17-hour flight from Rabat in Morocco and landed at Madrid's main airport overnight early on Saturday, his team said in a statement.

"Deposits" of gold in electronic waste are around 50 times richer than ore mined from the ground, according to figures put forward by recycling experts on Friday.

The amount of precious metal junked in cellphones, laptop computers, PCs and other electronic goods is rising hugely but very little of it is recovered, they said.

A period of intense, natural changes in climate caused coral reefs in the eastern Pacific to shut down thousands of years ago, and human-induced pollution could worsen the trend in the future, scientists said Thursday.

The study in the U.S. journal Science points to sea temperature fluctuations -- brought on by the same phenomenon that causes El Nino and La Nina events every several years -- as the main cause for the coral die-off near the Panama coast.

Scientists in the United States say they have made the world's most advanced pair of biomechanical legs, bringing the goal of human-friendly household robots a bit closer.

About half the size of their human counterparts, the legs are the first to mimic walking in a biologically accurate, energy-efficient manner, say the researchers.

A scientific body on Thursday urged Mexico and New Zealand to take immediate action to prevent the extinction of small marine mammals that are being killed by gillnets set by the fishing industry.

The International Whaling Commission voiced fears for Maui's dolphins -- some of the world's smallest dolphins found only on New Zealand's North Island -- and the vaquita, a 1.5-meter (five-foot) porpoise in the Gulf of California.