leagues and, in many cases, students, of Professor Onsager. Professor Onsager, himself, has contributed a paper on Illife in early times" to the volume. Among the topics discussed are some interesting applications of low temperature experimental techniques to cardiology and astrophysics. We would like to express our particular appreciation to Mrs. Helga Billings and Miss Sara Lesser for their excellent typing of these Proceedings and to Mrs. Jacquelyn Zagursky, as well as to Mrs. Billings and Miss Lesser for their invaluable assistance with the details of the conference and the publication of these Proceedings. The Editors CONTENTS Section One BIOLOGY Life in the Early Days Lars Onsager.

"Optimal Control" reports on new theoretical and practical advances essential for analysing and synthesizing optimal controls of dynamical systems governed by partial and ordinary differential equations. New necessary and sufficient conditions for optimality are given. Recent advances in numerical methods are discussed. These have been achieved through new techniques for solving large-sized nonlinear programs with sparse Hessians, and through a combination of direct and indirect methods for solving the multipoint boundary value problem. The book also focuses on the construction of feedback controls for nonlinear systems and highlights advances in the theory of problems with uncertainty. Decomposition methods of nonlinear systems and new techniques for constructing feedback controls for state- and control constrained linear quadratic systems are presented. The book offers solutions to many complex practical optimal control problems.