Note 11 - Warrants (Tables)

9 Months Ended

Sep. 30, 2013

Warrants [Abstract]

Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]

Warrants	Number of Warrants Issued			Weighted Average Exercise Price
Warrants outstanding at December 31, 2012		1,747,478		$	15.17
Warrants granted in connection with the Preferred Stock Offering, as more fully described in Note 9		1,341,382		$	5.31
Warrants exercised for common stock		(15,833	)		14.63
Warrants outstanding at September 30, 2013		3,073,027		$	10.89
Aggregate intrinsic value of outstanding warrants at September 30, 2013	$	-
Weighted average remaining contractual terms (in years)		3.7

Schedule of Common Stock Warrant Liability Valuation Assumptions [Table Text Block]

	September 30, 2013					December 31, 2012
Risk-free interest rate		0.33	-	1.39	%		0.73	%
Expected volatility		60.0	-	111.26	%		92.0	%
Expected life (in years)		1.5	-	4.4			1.13
Expected forfeiture rate				0.0	%		0.0	%
Expected dividend yield				0.0	%		0.0	%

Schedule of Common Stock Warranty Liability [Table Text Block]

Beginning balance as of January 1, 2013	$	4,283,932
Warrant liability classification (see Note 9)		9,110,302
Gain from the adjustment for the change in fair value included in net income		(8,141,574	)
Ending balance as of September 30, 2013	$	5,252,660