According to the United Nations, we are losing about 200 species per day--a thousand times the normal background rate of extinction. How does this stack up to previous mass extinctions? Scientific American editor Fred Guterl explains.
Deadline: Jan 27 2014
Reward: $15,000 USD
The Dow Chemical Company is the leading producer of polyalkylene glycols (PAGs) used in synthetic fluids and lubricants where petroleum,
Deadline: Jan 12 2014
Reward: $10,000 USD
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