Abstract: Compositions and methods are provided to identify functional mutant ribosomes that may be used as drug targets. The compositions and methods allow isolation and analysis of mutations that would normally be lethal and allow direct selection of rRNA mutants with predetermined levels of ribosome function. The compositions and methods of the present invention may be used to identify antibiotics to treat a large number of human pathogens through the use of genetically engineered rRNA genes from a variety of species. The invention further provides novel plasmid constructs to be used in the methods of the invention.

Abstract: A master cylinder reservoir is provided with flexible arms adapted to snap-engage with a retaining formation on a pressure cylinder, the arms lying generally parallel to a spigot of the reservoir received within a socket of the cylinder. A seal is provided between opposed surfaces of the spigot and socket.

Abstract: A vehicle brake servo booster has a housing divided into pressure chambers by a movable partition carried by a reciprocable hub member. A switch device is mounted on the housing and operable by an abutment member carried by a reciprocable piston to control an electrical circuit supplying a vehicle rear brake warning light.