The workshops that have been held over the past few years and the volumes published in their wake have proved highly successful and have prompted us to press on with our initial plans. Our basic aim was to tackle certain very important problems in respiratory rehabilitation and then discuss the various issues with people from all over the wodd engaged in the updating of experience and know ledge in this field. We therefore firmly believe that this ongoing effort is of fundamental importance. Hyperinflation, which is still a poody defined c1inical and physiopatho logical condition, is the focal point ofthis present study, which is aimed at discussing and weighing up the physiopathological mechanisms, c1inical consequences, and rehabilitation possibilities in a disease in which, until relatively recently, rehabilitation had seemed almost totally ineffective. The present contributions, however, show us how very important and versatile rehabilitation may be in its treatment. Perhaps, if we consider this branch of medicine as one which now no longer simply draws upon other sciences, but make an active contribution in its own right, we will have touched upon the most important aspect of this study. If I may, I would just like to add how very pleasing it is for me to acknow ledge how much this joint effort has contributed, in terms of true insights and above all VI results, to finding solutions to the problems addressed in reeent years.

In his review of the Proceedings of the First International Workshop on Respiratory Muscles in Chronic Obstructive Pulmonary Disease, organized in Montescano in 1986, Thomas K. Aldrich stated that "there is little information on nutrition". We felt that the need to supplement the evaluation of respiratory muscles by studying nutritional problems was an important enough matter to justify producing a specific study on the subject. This book is the result of the efforts made in this direction. Since 1986, many of the problems associated with nutrition and ventilatory function have been elucidated, and we hope that the contents of this book may contribute towards spreading interest and knowledge in this sector, particularly among those working in the field of respiratory rehabilitation. The physiological and clinical aspects of nutritional problems and the therapeutic approaches adopted in different disease conditions are dealt with in these pages by some of the best-known researchers in the field, providing abundant evidence, if any should be needed, that rehabilitation is not merely exercise. The picture strongly emerging over these last few years is that rehabilitation is not merely a matter of knowledge of lung or respiratory muscles, but also of heart-lung interaction, metabolic equilibrium and nutrition. So much for recent developments, but what does the future hold in store? May 1992 RENATO CORSICO Preface Nutrition and ventilation are inextricably related.

Respiratory rehabilitation can be defined as long term evaluation and therapy. This definition has evolved considerably from earlier and more restrictive attempts to delineate the discipline. Currently, respiratory rehabilitation involves evaluation techniques and treatment strategies which utilize the benefits gained from exercises, but without being limited to it. Respiratory muscle training, non-invasive mechanical ventilation, bronchodilator drugs, and metabolic balance and maintenance of nutrition are just a few of the topics covered in this book. The editors have organized the text to provide an updated review of the topic and indicate many areas in need of development and exploration in the years ahead. The information provided is easily accessible to a broad spectrum of readers, including clinicians, researchers, pharmacologists, technicians and therapists.

This volume represents the final report of the Selz Foundation Yaxuna Archaeological Project at the Precolumbian Maya center of Yaxuna, Yucatan, Mexico from 1986 to 1996. This volume contains summaries of all survey data, excavations, artifact analyses, and current interpretations. Contents: 1) Introduction; 2) Background to the investigations; 3) The natural setting; 4) Chronology (Yaxuna Ia (750/500 B.C.-250 B.C.), Yaxuna Ib (250 B.C.-A.D. 250), Yaxuna IIa (A.D. 250-A.D. 400), Yaxuna IIb (A.D. 400-A.D. 550), Yaxuna IIc (A.D. 550-A.D. 600), Yaxuna III (A.D. 600-700/730), Yaxuna IVa (A.D. 700/730-A.D. 900/950), Yaxuna IVb (A.D. 900/950- A.D. 1100/1200), Yaxuna V (1100/1200-1400?), Yaxuna VI (?)), 5) Excavations; 6) Conclusions; Appendices.