Earnings Per Share (Tables)

6 Months Ended

Jun. 30, 2013

Earnings Per Share [Abstract]

Schedule of the components of the calculations of basic and diluted earnings per share

		Three Months Ended				Six Months Ended
		June 30, 2013		June 30, 2012		June 30, 2013		June 30, 2012
Numerator:
	Net loss attributable to common shareholders	$	(9,338,067)	$	(6,479,554)	$	(17,914,446)	$	(13,062,656)
Denominator:
	Weighted average number of common shares
	outstanding	68,662,067		37,853,358		58,669,943		30,645,479

Schedule of potential dilutive common shares

	At June 30,
	2013		2012
Stock options outstanding		1,958,602	2,005,657
Unvested restricted stock		-	275,262
Common stock warrants (1)	25,403,905		9,421,008
Preferred stock (2)	10,972,862		-
Number of dilutive potential common shares	38,335,369		11,701,927

(1)

On May 31, 2011, the Company issued 7,128,563 warrants as part of an underwritten public offering.  As a result of the March 28 and 29, 2012 and February 20 and 21, 2013 public offerings, and the May 8, 2013 issuance of Series C redeemable convertible preferred stock described in Note 5, the number of warrants increased to 20,762,805.  Additionally, on February 20, 2013 the Company issued 23,637,500 warrants as part of an underwritten public offering. Of the warrants issued in February 2013, 18,996,400 were exercised as of June 30, 2013.

(2)

The preferred stock amount represents the dilutive potential common shares of the 10,431 shares of Series C redeemable convertible preferred stock issued on May 16, 2013.