A fluid-filled bladder for an article of footwear is disclosed that includes a sealed outer barrier and a tensile member. One example of a method is a method for inducing differentiation of cells into chondrocytes comprising providing aggrecan sensitive isolated dermis cells and seeding the cells onto an aggrecan coated surface. The low frequency circuit then is used to measure time after the high frequency circuit has lost power. Addressing is provided to control which car of the train is to be decoupled.