A vehicle safety restraint system comprises a portable base having a mounting assembly and a restraint assembly. Some of the caps include two portions that can be coupled together and that include a dispensing system that has at least two open positions and at least one closed position. The control system is operably connected to the dynamic interface and controls the changing geometry of the dynamic interface. A control system performs position control with respect to the piston member by controlling the servo valve based on a detection signal from the position sensor, a position command value, a velocity command value, and an acceleration command value. The first output shaft is connected in a hydraulic braking circuit including a positive displacement pump and an operator controlled variable flow valve for varying the resistive torque on the output shaft and effective a gear ratio change at the other output shaft. Further provided are assays for the identification of bioactive agents capable of modulating proliferation, survival, morphology and migration in mammalian cells.