The present invention relates to amniotic fluid specific polypeptide and a method for detecting rupture of the amniotic membranes. The first converter circuit converts the source voltage into a first voltage or a second voltage. In response, the light source of the unit is deactivated to prevent collisions with upstream data from other optical network units in the network. Four NFET pair arrangements are personalizable by via placement by a designer or design automation program. The liner further includes a mount means, such as a generally continuous annular groove, or a vent means, such as a plurality of recesses or grooves positioned circumferentially about the upper portion of the liner, or both a mount means and vent means used in functional combination.