This excerpt taken from the ELN 20-F filed Feb 26, 2009.
Assets Measured at Fair Value on a Non-recurring Basis
We measure certain assets, including equity investments in privately held companies, at fair value on a nonrecurring basis. These assets are recognized at fair value when they are deemed to be other-than-temporarily impaired. During 2008, we recognized an impairment charge of $0.9 million as a result of measuring at fair value a non-current investment in a privately held biotechnology company. At December 31, 2008, the fair value of this investment was measured at $1.1 million based on Level 3 inputs, with estimates derived from the companys financial statements and benchmarking to similar public companies. This investment is included in the non-current equity securities balance of $7.7 million presented in Note 11, with the remaining $6.6 million comprised of equity securities carried at cost.