Methods, systems, and computer program products for facilitating temporal comparison of medical images is provided, with one exemplary application being for breast mammograms. The degree of shading in each pixel within the single transparent membrane is controlled by controlling percentage of light transmitted according to the control command issued by the programmable controller. The invention may be screwed onto a tire valve stem. The connection frame is disposed at a bottom of the body. The process broker handler may be operable to instantiate the process broker and to instantiate an adapter stored in association with the instantiated process broker.