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7. Share-based Compensation (Details)	3 Months Ended		6 Months Ended
7. Share-based Compensation (Details)	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Share-Based Compensation Details
Risk free interest rate	0.76%	0.00%	0.80%	2.25%
Dividend yield	0.00%	0.00%	0.00%	0.00%
Expected term (in years)	7 years	0 years	6 years 6 months	6 years
Volatility	104.95%	0.00%	103.12%	93.00%

The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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