7. Derivative liability (Tables)

12 Months Ended

Dec. 31, 2012

Derivative Liability

The derivative liabilities were valued using a probability weighted average series of Black-Scholes-Merton models

			Fair Value of Warrants
	No. of Warrants		December 31, 2011		2012 Issuance		December 31, 2012
Risk-free interest rate			0.12%		–		0.02%
Expected volatility			92%		–		165%
Expected life (in years)			0.75 – 1.00		–		0.04
Expected dividend yield			0%		–		0%
Fair Value:
2009 Summer Warrants		–	$	332,998		–	$	–
2009 Wellfleet Warrants		–		17,807		–		–
2009 Fall Warrants		4,412,500		1,292,334	$	–		3,221,138
Total Fair Value		4,412,500	$	1,643,139	$	–	$	3,221,138