presents or causes to be presented to an officer ... of the United States government ... a false or fraudulent claim for payment or approval ... is liable to the United States government for a civil penalty of not less than Five Thousand Dollars and not more than Ten Thousand Dollars plus three times the amount of damages which the government sustains because of the act of that person____” On the same date there likewise became effective an amendment to 31 U.S.C. § 3731 which provides in part as follows: “In any action brought under § 3730 the United States shall be required to prove all essential elements of the cause of action including damages by a prepo .Iowa 1987) (strictly construing statute to apply prospectively only); United States v. Hill, 676 F.Supp. 1158 (N.D.Fla.1987) (<HOLDING>). In a well-reasoned opinion in Hill, Judge
holding no retroactive application recognizing a general principle that retroactive application of rules is permitted absent any manifest injustice holding that retroactive application of amendments will not result in manifest injustice holding retroactive application holding that retroactive application of statute turns on legislative intent and whether retroactivity works either unconstitutional interference with vested rights or manifest injustice