                                POWER OF ATTORNEY


         KNOW ALL MEN BY THESE PRESENTS, that Subhendu Guha whose signature
appears below constitutes and appoints Jay B. Knoll and Ghazaleh Koefod, and
each of them, as his or her lawful attorneys-in-fact and agents, with full
power of substitution and resubstitution, for him or her and in his or her
name, place and stead, in any and all capacities, to sign any Form 3, Forms 4
and Forms 5 and all amendments thereto and to file the same and other documents
in connection therewith, with the Securities and Exchange Commission, granting
unto such attorney-in-fact and agent full power and authority to do and perform
each and every act and thing requisite and necessary to be done in connection
therewith, as fully to all intents and purposes as he might or could do in
person, hereby ratifying and confirming all that such attorney-in-fact and
agent, or any of them, or their substitute or substitutes, may lawfully do or
cause to be done by virtue hereof.



Date: August 27, 2007                       By: /s/ Subhendu Guha
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                                                       Signature


