Underwater Physiology is a collection of papers that deals with the physiologically limiting effects of undersea, high pressure exposure ranging from fundamental biological reactions, through integration of physiological stresses, and to limits actually experienced in deep diving. Papers discuss oxygen, the mechanisms of toxicity, and the effects of oxygen on cells and systems such as its pathological and physiological influences in the neurosensory ocular tissue. Other papers discuss the physical effects of pressure and gases on cellular function, protein structure, and the possibility of alleviating symptoms through the administration of drugs. Tests in mice show that various gases exhibit qualitative and semi-quantitative differences in the characteristics of sickness, reactions to hypoxia, and the time before the onset of symptoms. A computer, programmed for nonlinear gas transfer and other variables, running in real time can compute directly from the breathing mixture and provide a real time solution to decompression sickness under various conditions. A combined therapeutic approach, recompression and dextran (an effective lipemic clearing agent) should be capable of treating decompression sickness in humans. Other papers investigate the influence of inert gases and pressure on the central nervous system, as well as, situations in undersea and manned chamber operations. This collection can prove valuable for physiologists, biochemists, cellular biologists, and researchers involved in deep sea diving.

Opening Speech of the ICEDIVE 84 Conference by His Royal Highness Prince Bertil of Sweden I am very pleased to be invited to open the International Conference ICEDIVE 84, dealing with medical and technical problems of diving and related underwater activities in arctic conditions. Until recent times, the arctic was considered astrange and remote area of minor importance. However, in a world with diminishing natural resources, arctic areas have become a region of global importance because of their enormous resources and strategie position. Certain experts believe that more than 50% of oil reserves are "sleeping" in these northern areas which are cold, harsh and hostile to man. Operations in arctic areas are extremely difficult, expensive, and demand high levels of technical, scientific and physiological achievement. One should recall for example, that Alaskan oil investment onIy became economically viable after the 1973-1974 price explosion. Recent political/military troubles in the Gulf have increased interest in the development of polar resources. This conference is unique as it is the first time that medical and technical specialists interested in the problem of diving in arctic conditions have met in an international forum. Development of the arctic resources is a matter of international urgency, and it pleases me that scientists from the USA, Canada, the USSR, Australia and Europe have gathered here in Stockholm to present their experience and to discuss problems in this field.

The success of any space flight mission depends not only on advanced technology but also on the health and well-being of crew members. This book, written by an astronaut physician, is the first practical guide to maintaining crew members health in space. It combines research results with practical advice on such problems as bone loss, kidney stones, muscle wasting, motion sickness, loss of balance, orthostatic intolerance, weight loss, and excessive radiation exposure. Additional topics include pre-flight preparation, relevant gender differences, long-duration medical planning, post-flight rehabilitation, and the physiology of extra-vehicular activity. Designed as a handbook for space crews, this text is also an invaluable tool for all the engineers, medical personnel, and scientists who plan and execute space missions.

This handbook attempts to translate data on various parameters of man's capability in underwater and hyperbaric environments for those without a background in the life sciences. Accomplishing any multifaceted task requires team work, and effective team work depends on facile communication among all participants. To communicate properly, all parties must understand each other's problems and be able to speak a similar language. To this end we believe that this publication will go a long way in furthering the understanding and communication necessary for maximum achievement. The U. S. Navy has a fundamental interest in all types of activities connected with the ocean and is especially interested in the growing field of manned underwater and hyperbaric activities. Thus, the manuscript for this comprehensive book was developed under Office of Naval Research contract N00014-67-A-0214-0013 with The George Washington University. We acknowledge with appreciation the financial support and technical guidance for this undertaking by the Naval Medical Research and Develop ment Command of the Bureau of Medicine and Surgery as well as by the Engineering Psychology Program and the Physiology Program of the Office of Naval Research. JOSEPH P. POLLARD Director Biological and Medical Sciences Division Office of Naval Research vii Preface A need was felt for a book that would document the relationship of the human being to the underwater hyperbaric environment in such a way that the individual unfamiliar with the psychological or biomedical jargon could still understand and appreciate the information.

The success of any space flight mission depends not only on advanced technology but also on the health and well-being of crew members. This book, written by an astronaut physician, is the first practical guide to maintaining crew members health in space. It combines research results with practical advice on such problems as bone loss, kidney stones, muscle wasting, motion sickness, loss of balance, orthostatic intolerance, weight loss, and excessive radiation exposure. Additional topics include pre-flight preparation, relevant gender differences, long-duration medical planning, post-flight rehabilitation, and the physiology of extra-vehicular activity. Designed as a handbook for space crews, this text is also an invaluable tool for all the engineers, medical personnel, and scientists who plan and execute space missions.