Many observers have recently noted that the international system is evolving into a multipolar world. At the same time, the notion of balance of power is being severely criticized for its vagueness and inconsistency. Seven empirically testable propositions which exemplify refined and narrowed...

Multiple branching trees have been used to model the acquisition of HIV drug resistance mutations, and several different algorithms have been developed to construct the tree set that best describes the data. These algorithms have mainly focused on the structure of the tree set. The focal point...