Mathematical sciences have been playing an increasingly important role in modern society. They are in high demand for investigating complex problems in physical science, environmental and geophysical sciences, materials science, life science and chemical sciences. This is a review volume on some timely and interesting topics in applied mathematical sciences. It surveys new developments and presents some future research directions in these topics. The chapters are written by experts in these fields, with a wide audience in mind and hence will be accessible to graduate students, junior researchers and other professionals who are interested in the subjects. The contributions of Professor Youzhong Guo, a leading expert in these areas, will be celebrated. His life and academic achievements are highlighted in the Preface and Postscript of the book. The underlying theme that binds the various chapters seamlessly is a set of dedicated ideas and techniques from partial differential equations and dynamical systems.