This issue of Endocrinology and Metabolism Clinics of North America is devoted to Reproductive Endocrinology. Guest Editors Peter Lee, MD and Christopher P. Houk, MD have assembled a group of expert authors to review the following topics: Fertility Among Females and Males with Congenital Adrenal Hyperplasia (21-Hydroxylase Deficiency); Reproductive Issues for Turner Syndrome; Fertility and Reproduction Among Childhood Cancer Survivors; Fertility After Crypotochidism; Male Obesity and Fertility; Fertility Issues among Transgender Individuals; Fertility Preservation in Pediatrics; Polycystic Ovary Syndrome (PCOS); Fertility Issues for Patients With Delayed Puberty (Constitutional Delay, Functional Delay, and Hypogonadotropism); Varicocele; Testis Development and Reproduction in Klinefelters Syndrome; and Fertility Issues Among Those With Disorders of Sex Development.

The production of a new version of any book is a daunting task, as many authors will recognise. In the field of computer science, the task is made even more daunting by the speed with which the subject and its supporting technology move forward. Since the publication of the first edition of this book in 1981 much research has been conducted, and many papers have been written, on the subject of fault tolerance. Our aim then was to present for the first time the principles of fault tolerance together with current practice to illustrate those principles. We believe that the principles have (so far) stood the test of time and are as appropriate today as they were in 1981. Much work on the practical applications of fault tolerance has been undertaken, and techniques have been developed for ever more complex situations, such as those required for distributed systems. Nevertheless, the basic principles remain the same.

Fault tolerance has been an active research area for many years. This volume presents papers from a workshop held in 1993 where a small number of key researchers and practitioners in the area met to discuss the experiences of industrial practitioners, to provide a perspective on the state of the art of fault tolerance research, to determine whether the subject is becoming mature, and to learn from the experiences so far in order to identify what might be important research topics for the coming years. The workshop provided a more intimate environment for discussions and presentations than usual at conferences. The papers in the volume were presented at the workshop, then updated and revised to reflect what was learned at the workshop.

"The end of the Cold War and the changing world strategic environment has brought about a dramatic shift in the emphasis of forces throughout the military. In the past decade, the U.S. has continually been sending ad hoc deployments of forces in reaction to Iraqi actions. Several times the Air Force has deployed forces to augment a Carrier Battle Group (CVBG) already in theater or to fill a gap left behind when a CVBG could not remain on station. This study compares the Aerospace Expeditionary Force (AEF), which will be implemented in January 2000, and the CVBG. In particular, it looks at the ability of each to project power throughout the world. The National Security Strategy guides and directs military doctrine. This study shows how joint doctrine, as well as Air Force and Navy doctrine, has developed to provide viable power projection forces. The AEF is a very capable, mobile force which brings flexible firepower to the fight. It is able to respond rapidly and provide combat operations within 72 hours of execution, anywhere in the world. The AEF is limited by logistics, host nation support and overfly rights. The CVBG is also a capable force, providing flexible firepower. It is expeditionary in nature, but is limited by sortie generation, logistics and speed of deployment. The situation will dictate what forces will be necessary to meet our objectives. Commanders of tomorrow will have to analyze the situation and determine the appropriate force required and decide whether to ask "Where is the Carrier?" or say, "Send an AEF ." -- Abstract.