Quarterly report pursuant to Section 13 or 15(d)

Derivative Instruments

Derivative Instruments
3 Months Ended
Mar. 31, 2013
Derivative Instruments [Abstract]  
Derivative Instruments
  7. Derivative Instruments


Certain embedded features of our convertible securities and notes payable, as well as warrants to purchase our common stock, may be treated as derivative liabilities. We do not use derivative instruments for hedging of market risks or for trading or speculative purposes.


Changes in the estimated fair values of our derivative liabilities are recorded in the consolidated statement of operations. The net effect of marking our derivative liabilities to market during the three-month period ended March 31, 2012 resulted in net increases in non-cash expense of $184,000. No derivative liabilities were outstanding as of March 31, 2013.