Security	Date	Code	Shares	Price	A/D	Owned after	D/I	Nature of ownership
Common Stock, par value $0.001^F1,F2,F3	Jan 6, 2015	S	10,054	$1.7623	D	1,457,323	I	see footnotes
Common Stock, par value $0.001^F1,F2,F3	Jan 7, 2015	S	3,800	$1.6811	D	1,453,523	I	see footnotes

Table II — derivative securities

No Table II lines on this filing.

Explanation of responses

F1The securities disposed of and reported on this Form 4 are owned by Wexford Spectrum Investors LLC ("WSI").
F2Wexford Capital LP ("Wexford Capital") may, by reason of its status as manager of WSI, be deemed to own beneficially the securities of which WSI possesses beneficial ownership. Wexford GP LLC ("Wexford GP") may, as the General Partner of Wexford Capital, be deemed to own beneficially the securities of which WSI possesses beneficial ownership. Each of Charles E. Davidson ("Davidson") and Joseph M. Jacobs ("Jacobs") may, by reason of his status as a controlling person of Wexford GP, be deemed to own beneficially the securities of which WSI possesses beneficial ownership. Each of Wexford Capital, Wexford GP, Davidson and Jacobs shares the power to vote and to dispose of the securities beneficially owned by WSI. (Continue with footnote (3)).
F3(Continued from footnote (2)). Each of Wexford Capital, Wexford GP, Davidson and Jacobs disclaims beneficial ownership of the securities owned by WSI and this report shall not be deemed as an admission that they are the beneficial owners of such securities except, in the case of Davidson and Jacobs, to the extent of their respective interests in each member of WSI.