The Company considers financial instruments which do not have fixed settlement provisions to be derivative instruments. The common stock purchase warrants issued with the Company’s August 13, 2007 private placement, and the common stock purchase warrants issued to the placement agent in the transaction, do not have fixed settlement provisions because their exercise prices may be lowered if the Company issues securities at lower prices in the future. The Company was required to include the reset provisions in order to protect the warrant holders from the potential dilution associated with future financings. At issuance, the warrants were recognized as equity instruments and have since been re-characterized as derivative liabilities. Accordingly, the warrant obligations are adjusted to fair value at the end of each reporting period with the change in value reported in the statement of operations. Such fair values were estimated using the Black-Scholes valuation model. Although the Company determined the common stock warrants include an implied down-side protection feature, it performed a Monte-Carlo simulation and concluded that the value of the feature is de minimis between the two models and the use of the Black-Scholes valuation model is considered to be a reasonable method to value the warrants.

The derivative liability related to warrants without fixed settlement provisions were valued using the Black-Scholes option valuation model and the following assumptions on the following dates:

The Company deems financial instruments which require net-cash settlement as either an asset or a liability. The common stock purchase warrants issued with the Company’s April 22, 2012 registered direct offering contain a net-cash settlement feature which gives the warrant holder the right to net-cash settlement in the event certain transactions occur. Pursuant to the terms of the warrants, if such a transaction occurs the warrant holder will be entitled to a net-cash settlement value calculated using the Black-Scholes valuation model using an expected volatility equal to the greater of 100% and the 100 day volatility obtained from the HVT function on Bloomberg, an expected term equal to the remaining term of the warrant, and applicable risk-free interest rate corresponding to the U.S. Treasury. Accordingly, the fair value of the warrant obligation was determined at the date of issuance and was adjusted to fair value at the end of the reporting period using the Black-Scholes valuation model. The change in value reported from issue date to the reporting date was recorded in the accompanying condensed consolidated statement of operations.

The derivative liability related to warrants with net-cash settlement provisions were valued using the Black-Scholes option valuation model and the following assumptions on the following dates:

The Company will continue to adjust the derivative liabilities for changes in fair value until the earlier of the exercise, at which time the liability will be reclassified to stockholders’ deficiency, or expiration of the warrants.

The following table sets forth a summary of the changes in the fair value of our Level 3 financial liabilities that are measured at fair value on a recurring basis: