If we knew what it was we were doing, it would not be called research, would it? Albert Einstein Seriously, if you could get read the study protocol or grant written by the PI, that should give you an explanation of every detail of the data collected. Connie McCoy, RVT Cincinnati Children's Hospital To unsubscribe or search other topics on UVM Flownet link to: http://list.uvm.edu/archives/uvmflownet.html