It is with great sadness that I share with you the news that Nathan Henry Cook, Professor Emeritus of Mechanical Engineering at MIT, was taken from our midst and from the activities of an extraordinarily creative working life. His longtime friend and colleague, Professor Serope Kalpakjian, reflects on his life, work, and legacy in the Memoriam printed in this issue.

With this issue, the Journal welcomes a new associate editor, Professor Dariusz (Darek) Ceglarek. He is well known in the community, and I appreciate his willingness to serve. Two associate editors, S. Jack Hu and Thomas Kurfess, have completed their second term. On behalf of our whole community and myself, I would like to thank them for six years of dedicated and excellent service to the Journal. Their bios appear in the issue.

To remain faithful to the tradition of the Journal, the services of four outstanding reviewers, as nominated by the associate editors, are recognized. They are: 
S. Jack HuUniversity of Michigan–Ann ArborBrad KinseyUniversity of New HampshireStephen MalkinUniversity of Massachusetts–AmherstCedric XiaFord Motor Company

Timely and thorough reviews, as exemplified by these reviewers, are essential for the further growth of the stature of the Journal. I would like to gratefully acknowledge their effort and dedication as well as the services of the long list of colleagues who have contributed as reviewers in 2005. Their names are listed in the back of the issue.

Best wishes from the editorial board and staff for a happy, healthy, and prosperous New Year.