be contrary to the legislative intent underlying the statute.”); United States v. Johnson, 999 F.2d 1192, 1196 (7th Cir.1993) (“To read the statute or Chapman as requiring inclusion of the weight of all mixtures, whether or not they are usable, ingestible, or marketable, leads to absurd and irrational results contrary to congressional intent.”); United States v. Rolande-Gabriel, 938 F.2d 1231, 1236 (11th Cir.1991) (“The Court in Chapman found that a plain meaning interpretation of “mixture” does not create an irrational result in the context of LSD and standard carrier mediums; however, in the present ease it would be irrational for the court to fail to distinguish between usable and unusable drug mixtures_”). See also United States v. Palacios-Molina, 7 F.3d 49, 53-54 (5th Cir.1993) (<HOLDING>). But see United States v. Mahecha-Onofre, 936
holding that the term cocaine base in 21 usc  841b1 refers to cocaine in its chemically basic form which includes but is not limited to crack cocaine holding that when intervening supreme court case law is clearly irreconcilable with a prior circuit decision a panel of this court is bound by the later and controlling authority and should reject the prior circuit opinion holding that a prior conviction for transporting cocaine was probative of the intent required for participation in a separate plan to transport cocaine holding waste liquids in which cocaine was transported not a mixture and distinguishing prior fifth circuit authority holding that all decisions of the old fifth circuit handed down prior to the close of business on september 30 1981 are binding precedent in the eleventh circuit