where pol r,p,j is the concentration of the replicating polymerases on the jth segment of the positive-sense anti-genomic nucleocapsids, l is the total length of the genome, and n sec is the total number of segments of the genome ( Figure 9B ). dpol r;p; j dt ¼ k e;pol n sec l À l trc À l lec ðpol r;p; j À 1 À pol r;p; j Þ j ¼ 2; . . . n sec ð20Þ dpol lec dt ¼ k e;pol n sec l À l trc À l lec pol r;p;nsec À pol lec l lec ð21Þ dðÀÞnc dt ¼ k e;pole ncap Á pol lec l lec À k d;nc ðÀÞnc ð22Þ