<P>Dedicated to the Russian mathematician Albert Shiryaev on his 70<SUP>th</SUP> birthday, this is a collection of papers written by his former students, co-authors and colleagues. The book represents the state-of-the-art of a quickly maturing theory and will be an essential source for researchers in this area. The diversity of topics and comprehensive style of the papers make the book attractive for Ph.D. students and young researchers.</P>
