This book deals with the statistical mechanics and dynamics of open quantum systems moving irreversibly under the influence of a dissipative environment. The basic concepts and methods are described on the basis of a microscopic description with emphasis on the functional integral approach. The general theory for the time evolution of the density matrix of the damped system is developed. Many of the sophisticated ideas in the field are explained with simple models. The discussion includes, among others, the interplay between thermal and quantum fluctuations, quantum statistical decay, macroscopic quantum tunneling and quantum coherence.Contents: IntroductionGeneral Theory:Traditional Approaches to Open Quantum SystemsSystem-Plus-Reservoir ModelsImaginary-Time Path IntegralsReal-Time Path Integrals and DynamicsSimple Dissipative Quantum Systems:Damped Harmonic OscillatorQuantum Brownian MotionQuantum-Statistical Decay:Introduction to the ProblemThe Crossover Temperature T0Thermally Activated DecayThe Crossover RegionDissipative Quantum TunnelingThe Dissipative Two-State System:IntroductionThermodynamicsTwo-State DynamicsDynamical SimulationThe Dissipative Multi-State System:IntroductionGeneral FormalismDynamics at Long TimesReadership: Condensed matter and statistical physicists.Key Features:Brings together state-of-the information on stem cellsComprehensive coverage of all aspects of stem cellsContributions by renowned scientists in specific fieldsExtensive self-explanatory figures, color photos, graphics