The objective of the present invention is to provide a process for simple and efficient preparation of an intermediate compound to synthesize a gadolinium complex having a substituent for improving a retention property in blood time and specificity to an intended organ. The control terminal of each of the m transistors is configured to receive a control signal that adjusts an activation state of the transistor. A second measuring device generates a second measuring signal that represents a function of fiber rope density and fiber geometry. Many different straps of the harness allow the operator of the stokes litter victim harness to adjust the left leg opening, the right leg opening, and other related spacing so that the victim can be secured within the harness. The embodiment of the circuit and method disclosed herein include novel implementations of a time-slot interchange circuit and a telephony signaling circuit. In various embodiments, the system is configured to optimize the pairings based at least in part on one or more needs of the one or more students, as well as teacher, classroom, activity and resource availability.