35q9235r3537n2549j1092c5092d2535b3235b3535b50 applications bifurcation biology biologyandothernaturalsciences biomathematics calculusofvariationsandoptimalcontrol;optimization cellularandmedicaltopics dynamicalsystemsandergodictheory dynamicalsystemsinbiology ecology equationsofmathematicalphysicsandotherareasofapplication existencetheories freeboundaryproblems freeproblemsintwoormoreindependentvariables mathematicalmodels mathematics maximumprinciples medicalapplications(general) miscellaneoustopics partialdifferentialequations pdesinconnectionwithbiologyandothernaturalsciences physiological populationdynamics(general) probabilities probabilitytheoryandstochasticprocesses qualitativepropertiesofsolutions stability theoreticalecology/statistics