Star polymers of soft segment forming monomers are useful in forming surgical devices. Pressured water, such as at 50 psi from a tap water source, provides the pressured feed water during filtrate production, and also pressurizes the filtrate during backflushing. In several embodiments, the object storage system includes a ring implementation used to associate object storage commands with particular physical servers such that certain guarantees of consistency, availability, and performance can be met. The connecting rod is mounted on the piston pin with the piston pin bushing therebetween. An agent associated with the first digital data processor that responds to the assignment by extending the file system to include the assigned storage device.