Aptitude, who has not raced since finishing third in the Belmont Stakes (gr. I), recorded his first official work Tuesday, going three furlongs in :37.60. Aptitude, trained by Bobby Frankel, is at Del Mar. Also working at the seaside track Tuesday was Captain Steve. The colt is pointed at the Sept. 16 Kentucky Cup Classic (gr. II), and in preparation worked seven furlongs in 1:26...Michael Buckley has joined the staff of Ireland's Kildangan Stud. Buckley will work with the Darley satellite as nominations manager at the farm and for the operation's stallions worldwide...Middle Park Stakes (Eng-I) winner Lujain has been retired and will enter stud next year at Dalham Hall Stud near Newmarket, England. Raced by Sheikh Mohammed's Godolphin Racing, the 4-year-old son of Seeking the Gold won half of his six career starts, with all his victories coming from four starts as a juvenile. The colt, who is from the same female family as successful sires Miswaki and Southern Halo, will stand for 5,000 pounds...The purse for next year's Tampa Bay Derbyon March 18, 2001, has been increased to $200,000, up from its $150,000 value for this year's renewal. The race for 3-year-old highlights a $1.5 million stakes schedule for the 93-day meet that begins Dec. 16 and concludes May 6...Highland Park, the sire of grade I winners Love That Red and Highland Talk, has been relocated to Loren and Nancy Bolinger's Running Horse Farm in Albuquerque, N. M., where he will stand for $1,500. The 20-year-old son of Raise a Native has sired nine stakes winners.