“…By making use of flux cytometry technologies for instance, it is possible to determine cell populations with certain properties as protein content on a large scale of tenths of thousands of cells. In other applications, like coagulation fragmentation equation [8,9,10,11,12], or prion aggregation and fragmentation [13,14,15], similar equations arise, and much less is known on aggregate size repartition. The division rate B(x), on the contrary, is not directly measurable.…”