126 S.Ct. 786, 163 L.Ed.2d 609 (2005). Accordingly, we hold Selby has failed to demonstrate the district court erred in using 405 months as the starting point for applying the substantial-assistance departure. We further hold that Selby’s reliance on section 3582(c)(l)(A)(ii) is misplaced because that provision does not set the definitive standard as to what is meant by a life sentence under the statutory sentencing framework. Rather, it applies to the discretionary modification of a sentence for a defendant who is at least 70 years old, has served at least 30 years in prison, and is no longer considered dangerous. Selby’s reliance on Prevatte likewise is misplaced because Prevatte does not involve the application of a mandatory minimum sentence of life. See Prevatte, 66 F.3d at 843 (<HOLDING>). For the foregoing reasons, we affirm. 1 . The
holding unconstitutional defendants sentence of death based upon the holding in roper supra and remanding for the montgomery circuit court to set aside the defendants death sentence and to sentence him to the only other sentence available  life in the penitentiary without the possibility of parole holding 636month sentence was abuse of discretion in light of seventh circuits prior holding that where legislatively enacted sentencing scheme has expressly deprived court of possibility of imposing life sentence sentence for term of years exceeding defendants approximate life expectancy would ordinarily constitute abuse of discretion quotation omitted recognizing that we review the sentence imposed by a district court under the abuse of discretion standard holding that an effective life sentence of fortyfive years for seconddegree forgery was excessive and that a life sentence was cruel and unusual in violation of the eighth amendment holding that in order to aid the appellate review of whether an abuse of discretion has occurred at sentencing the trial court is required to articulate on the record reasons for imposing a particular sentence