This book was originated from a series of lectures given in a course on the physical properties of biological membranes and their functional implica tions. The course was intended to allow students to get acquainted with the physical techniques used to study biological membranes. The experience was valuable and we feel that a detailed description of the procedures used and of various examples of the results obtained allowed many students to become familiar with a theme that is not often part of regular courses on membrane physiology or biophysics. This book is designed as a tutorial guide for graduate students interested in understanding how physical methods can be utilized to study the proper ties of biological membranes. It includes first a detailed description of applications of physical techniques-such as X-ray fiber diffraction methods (Chapter 1), 2H and 13C NMR spectroscopy (Chapter 2), and calorimetry (Chapter 3)-in the study of the properties of lipid model membranes. A description of how to measure molecular mobility in membranes (Chapter 4) follows, and the book concludes with three chapters in which biological membranes are the subject of study. Chapter 5 deals with the acetylcholine receptor and its membrane environment; Chapter 6 discusses how fluorescence techniques can be applied in the study of the calcium ATPase of sarcoplasmic reticulum; and Chapter 7 explains how protein lipid interactions modulate the function of the sodium and proton pumps."

The present volume originated from the workshop "Transduction in Biological Sys tems," held at the Marine Biological Station of the Universidad de Valparaiso, Mon temar, Chile, May 23-30, 1988, and contains contributions from most of the partici pants in the workshop. The title of both the workshop and the book reflects accurately the central theme discussed during several days of intense debate and profound intellectual exchange in the peaceful environment offered by the central coast of Chile. It was apparent that the workshop was a great success-a sentiment expressed by many seasoned attendees, some of whom dared opinions as strong as "It was the best ever." There is no single reason to explain why this workshop was so successful. Certainly instrumental was the incredible effort displayed by the Chilean Organizing Committee in selecting adequate facilities and in organizing social events that supplemented the scien tific sessions and provided an authentic fraternal environment for the participants. Equally important were the foreign participants, who enthusiastically gave of their time to take part in the event, and the students, who came from Chile as well as from several other Latin American countries, and who applied the necessary pressure in their repeated demands for scientific clarity, accuracy, and sincerity."