Institution: | A1 Department of Mathematics and Physics, The Royal Veterinary and Agricultural University, Thorvaldsenvej 40, DK-1871 Frederiksberg C, Denmark E-mail: torbenm@dina.kvl.dk A2 Department of Biostatistics, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark E-mail: ts@biostat.ku.dk |