Linear differential equations, Routh-Hurwitz criteria, first-order systems. Local stability in the first-order nonlinear systems, phase-plane analysis, periodic solutions, bifurcations, global stability, Liapunov functions, persistence and extinction theory. Harvesting a single population, predator-prey models, competition models, spruce budworm models, chemostat models, epidemic models, Hodgkin-Huxley, Fitzhugh-Nagumo models and/or models of molecular events.