A new metric applicable to the characterization and design of multimode fiber is described. In selected implementations, sulfur level in the activated carbon is relatively low and the binder is inert. In another embodiment, stack annular metallic disks are used. An air moving apparatus draws cooling air external to the cabinet into the first interspace region, wherein the cooling air passes over the plurality of electronic modules in a substantially horizontal manner and substantially parallel to the front surface and the rear surface, wherein the cooling air subsequently enters the second interspace region and is thereafter exhausted from the cabinet. When the cows are finished being milked the first actuating system then disengages from the cows’ briskets and the second actuating system vertically raises the cow brisket bar assembly to allow the cows to pass thereunder. In particular, it relates to Adeno-associated virus vectors with modified capsid proteins and materials and methods for their preparation and use.