The present invention provides novel compounds of the Formula I and prodrugs thereof, geometric and optical isomers thereof, and pharmaceutically acceptable salts of such compounds, prodrugs and isomers, wherein R1 to R8 and W are as described herein. The overhead livestock enclosure washing system includes a track member coupled to the ceiling of the building. Hydraulic isolation between the interior and exterior of the tubular is provided by pressure barrier means at the slotted stations. AC coupling circuitry is between the input terminal and a node and couples the input signal into a coupled signal at the node.