.3 early participation payment , which is amortized over the life of the new floating rate notes as a discount , using an effective interest method , and recorded in interest expense . direct fees associated with the exchange of $ 3.5 were reflected in interest expense . 4.25% ( 4.25 % ) and 4.50% ( 4.50 % ) convertible senior notes in november 2006 , we exchanged $ 400.0 of our 4.50% ( 4.50 % ) convertible senior notes due 2023 ( the 201c4.50% ( 201c4.50 % ) notes 201d ) for $ 400