The registration of each hall call is recorded and the remaining response time of all available cars to each up hall call and each down hall call is determined. The predicate expression is employed to enable a transformation to be made that causes the conditional branch instruction to trigger, or execute, when an opposite condition is true. Agents including nucleic acids may be delivered intracellularly using the inventive pH triggerable particles. In one embodiment, the molecule is an antibody directed against a granulin peptide. In an embodiment, the hepatocytes and nonparenchymal cells are derived from disaggregated liver tissue and are co-cultured in the presence of epidermal growth factor or heptocyte growth factor and beads coated with extracellular matrix protein, Alternatively, the hepatic cell culture may be implanted into the body of a recipient host having a hepatic disorder. The machine vision system has an imaging device.