A mattress system for a patient includes an inflatable mattress having at least one inflatable bladder, each having at least one inflation port and a plurality of selectively sealable deflation pinholes. An application specifies that file system-related operations are to be handled as a transaction, and the application is given a file handle associated with a transaction context. The disclosed methods and apparatus allow for high quality flash photography not previously possible with such cameras, commonly found in mobile devices, or the like. The engine has an inlet channel which supplies fuel and combustion air into the combustion chamber as well as an exhaust outlet from which exhaust gases flow from the combustion chamber. A water gas shift reactor is upstream of the rotating pressure swing adsorber.