The workshop entitled "The Role of Cell Interactions in Early Neurogenesis" was held at the Institut d'Etudes Scientifiques in Cargese, Corsica on May 29th to June 3rd, 1983. The setting was ideal for a small meeting whose purpose was to generate as much discussion as possible between the various participants. One of the major topics of this conference was neural induction, that is, the first step in neurogenesis. Neural induction remains poorly understood at the molecular level as compared to the sub- sequent steps of neuronal migration and differentiation. It thus appeared important to unite different researchers working on this fundamental process of neural induction with scientists studying later steps of neurogenesis in order to exchange ideas and suggestions. We would like to acknowledge the invaluable assistance of Marie- France Hanseler, the administrative assistant of CNRS who is respon- sible for the Institute. The workshop was primarily sponsored by CNRS (Centre National de la Recherche Scientifique, France), NATO and EMBO (European Molecular Biology Organization). Additional financial support was generously provided by the International Society of Developmental Biologists, the European Developmental Biology Organiz- ation, the European Council, the Universite Paul Sabatier (Toulouse), la Societe Francaise de Biologie du Developpement, les Etablisse- ments Fabre (Fr~nce) et les Etablissements Sarget (France). The proceedings from this workshop comprise the present volume and there are five general chapters. In addition to the principal lectures given at the Institute, many participants presented short reports and all of these are included in this volume.

The Cargese Summer Institute 1B75 on Weak and Electromagnetic Interactions at High Energies was organized by the Universite Pierre et Marie Curie (M. LEVY et J. L. BASDEVANT), the Katholieke Universiteit te Leuven (R. GASTMANS) and the Universite Catholique de Louvain (D. SPEISER et J. WEYERS) who made in 1973 the first contacts with some lecturers, who, on the advice of NATO, joined th their efforts and worked in common. It was the 16 Summer Insti- rd tute held at Cargese and the 3 one organized by the two depart- ments of Theoretical Physics at Leuven and Louvain-Ia-Neuve. When the two groups decided (independently) on the subject of the school, they could not know how lucky their choice eventually would turn out to be : rarely has it been possible ~o present an audience with such a great number of new and decisive discoveries who are likely to stimulate the imagination of theoreticians and the research projects of experimentalists alike. Such were the decisive confirmation of the neutral currents, the di-muon events, the slowly decaying new particles, etc. The organizers were grate- ful indeed that they could find physicists from almost all great centers of high energy physics who had themselves participated in these discoveries. Although the theorists could not match during the last two years the spectacular success of their experimental colleagues, there has been enough important programs, especially in field theory : renormalization of gauge theories, the Brout- Englert-Higgs mechanism, etc...

Growth, as we conceive it, is the study of changeinan organism not yet mature. Differential growth creates form: external form through growth rates which vary from one part of the body to another and one tissue to another; and internal form through the series of time-entrained events which build up in each cell the special ized complexity of its particular function. We make no distinction, then, between growth and development, and if we have not included accounts of differentiation it is simply because we had to draw a quite arbitrary line somewhere. lt is only rather recently that those involved in pediatrics and child health have come to realize that growth is the basic science peculiar to their art. It is a science which uses and incorporates the traditional disciplines of anatomy, physiology, biophysics, biochemistry, and biology. It is indeed a part of biology, and the study of human growth is a part of the curriculum of the rejuvenated science of Human Biology. What growth is not is a series of charts of height and weight. Growth standards are useful and necessary, and their construction is by no means void of intellectual challenge. They are a basic instrument in pediatric epidemiology. But they do not appear in this book, any more than clinical accounts of growth disorders. This appears to be the first large handbook-in three volumes-devoted to Human Growth."

Recently there have been major developments in the experimental techniques available for the study of the primary events following the absorption of ultra-violet and visible radiation by biological systems. These techniques, which include absorption, emission, resonance Raman, electron spin resonance, nuclear magnetic resonance and photoacoustic spectroscopies, can be used to study the fate of transient species with lifetimes ranging from seconds to nanoseconds and extending in some cases, such as laser flash photolysis, to pico 12 15 (10- S)- and even femtoseconds (10- s). In parallel with these developments there has been a dramatic increase in the use of light in medicine via the direct photochemical alteration of endogenous molecules (phototherapy) or via the photoactivation of drugs in the skin or other tissue (photochemotherapy). Thus neonatal hyperbili rubinaemia can be routinely treated by phototherapy and psoriasis is frequently treated by PUVA photochemotherapy. A promising new photo chemotherapy used the phototoxicity of porphyrin drugs activated by red light to destroy solid malignant tumors. While some of the overall qualitative effects of such treatments are known, only recently have we begun to understand the associated molecular mechanisms. The primary molecular processes involve short-lived species. The pur pose of this Advanced Study Institute was to review some newer experi mental techniques for the study of such species, the application of these techniques to biological and medical systems and to examine the value of such information in phototherapeutic situations."

We live in era of transformation--of technology, of social values, and of the way work is done. This book represents a timely and innovative ad dition to current thinking and writing about transformation in organiza tions. In order to meet an increasingly global and competitive environment, organizations are undergoing reengineering, work process redesign, "right sizing," creating a "virtual office," and other forms of restructur ing and basic change of the way work is accomplished. Such transfor mation means analyzing and redesigning core processes in organizations around new kinds of principles such as "total quality" and customer service. The eventual effect of these changes is likely to be the networked or "boundary-Iess" organization, in which the tradi tional boundaries between functions and between producers and their suppliers-and sometimes even between organizations and their com petitors-are broken down. The goal of such transformation is to make the work of the organization more efficient and productive-to produce more with fewer resources and at a lower cost. In the conventional view of the transformation process, certain sec ondary concerns, such as the need to protect the environment or to help an increasingly heterogeneous work force deal with its personal issues, are seen as problematic for this core thrust. Some recent work, however, is beginning to show that if these so-called secondary concerns are con sidered central, far from being problematic, they actually present strat egy opportunities for productive innovation and change."

In today's complex world, we have come to rely increasingly on those who have expertise in specific areas and can bring their knowledge to bear on crucial social, political and scientific questions. Taking the viewpoint that experts are consulted when there is something important at stake for an individual, a group, or society at large, Experts in Science and Society explores expertise as a relational concept. How do experts balance their commitment to science with that to society? How does a society actually determine that a person has expertise? What personal traits are valued in an expert? From where does the expert derive authority? What makes new forms of expertise emerge? These and related questions are addressed from a wide range of areas in order to be inclusive, as well as to demonstrate similarities across areas. Likewise, in order to be culturally comparative, this volume includes examples and discussions of experts in different countries and even in different time periods. The topics include the roles of political experts, scientific experts, medical experts, legal experts, and more.

This book offers a step-by-step guide to the experimental planning process and the ensuing analysis of normally distributed data, emphasizing the practical considerations governing the design of an experiment. Data sets are taken from real experiments and sample SAS programs are included with each chapter. Experimental design is an essential part of investigation and discovery in science; this book will serve as a modern and comprehensive reference to the subject.

The goals of the science of photobiology can be divided into four categories: to develop (I) ways to optimize the beneficial effects of light on man and his environment, (2) methods to protect organisms, including man, from the detrimental effects of light, (3) photochemical tools for use in studies of life processes, and (4) photochemical therapies in medicine. To achieve these goals will require the knowledgeable collaboration of biologists, chemists, engineers, mathematicians, physicians, and physicists; because photobiology is a truly multidisciplinary science. While a multidis ciplinary science is more intellectually demanding, it also has a greater potential for unexpected breakthroughs that can occur when data from several areas of science are integrated into new concepts for theoretical or practical use. Photochemical and Photobiological Reviews continues to provide in depth coverage of the many specialty areas of photobiology. It is hoped that these reviews will provide an important service to the younger scientists in the field and to senior scientists in related fields, because they provide a ready access to the recent literature in the field, and more importantly, they frequently offer a critical evaluation of the direction that the field is taking, or suggest a redirection when appropriate. Since it is important that this review series remain responsive to the needs of photochemists and photobiologists, the Editor would value com ments and suggestions from its readers."

During August 1983, a group of 89 physicists from 59 labora tories in 23 countries met in Erice for the 21st Course of the International School of Subnuclear Physics. The countries repre sented were Algeria, Australia, Austria, Canada, Czechoslovakia, the Federal Republic of Germany, Finland, France, Hungary, India, Israel, Italy, Japan, the Netherlands, South Africa, Spain, Sweden, Switzerland, Taiwan, Turkey, the United Kingdom, the United States of America, and Yugoslavia. The School was sponsored by the European Physical Society (EPS), the Italian Ministry of Education (MPI), the Italian Ministry of Scientific and Technological Research (MRST), the Sicilian Regional Government (ERS), and the Weizmann Institute of Science. The programme of the School was mainly devoted to a review of the most significant results, both in theory and experiment, obtained in the field of the "electroweak" and of the "colour" forces of nature. The outcome of the Course was to present a clear picture of how far we are from the electronuclear formulation of these basic forces acting between quarks and leptons. And more generally, how far we are from the unification of all gauge forces of nature."

The Pade approximation problem is, roughly speaking, the local approximation of analytic or meromorphic functions by rational ones. It is known to be important to solve a large scale of problems in numerical analysis, linear system theory, stochastics and other fields. There exists a vast literature on the classical Pade problem. However, these papers mostly treat the problem for functions analytic at 0 or, in a purely algebraic sense, they treat the approximation of formal power series. For certain problems however, the Pade approximation problem for formal Laurent series, rather than for formal power series seems to be a more natural basis. In this monograph, the problem of Laurent-Pade approximation is central. In this problem a ratio of two Laurent polynomials in sought which approximates the two directions of the Laurent series simultaneously. As a side result the two-point Pade approximation problem can be solved. In that case, two series are approximated, one is a power series in z and the other is a power series in z-l. So we can approximate two, not necessarily different functions one at zero and the other at infinity.

This, the ninth volume in the series, appears some 13 years after the first. Like most of its predecessors, Volume 9 is deliberately eclectic, covering a range of topics that the editors think worthy of inclusion. Some of the chapters, such as the review of the literature on benzodiazepines, represent areas that have received relatively little attention in previous volumes-largely because the literature has not previously been "ripe" for review. Others represent literatures that have been reviewed in the past but which continue to advance in sufficient measure that their ripening never ceases. Shepard Siegel's contribution represents a relative rarity in previous volumes: a chapter not laden with a consideration of current empirical work, but a reflective essay designed to stir thought with some pro vocative ideas. The editors trust that readers will continue to find Research Advances to be an important repository of knowledge in the alcohol and drug fields. The Editors Toronto IX Contents 1. THE HUMAN PHARMACOLOGY OF NICOTINE Neal L. Benowitz 1. Introduction 2. Nicotine in Tobacco Products 2 3. Phannacokinetics of Nicotine 4 4. Nicotine and Cotinine Blood Levels during Tobacco Use 14 5. Intake of Nicotine during Cigarette Smoking 18 6. Biochemical Markers of Nicotine Intake 18 7. Regulation of Nicotine Intake during Cigarette Smoking 23 8. Phannacology of Nicotine 28 9. Importance of Nicotine in Human Disease 41 References 45 2. BENZODIAZEPINES AS DRUGS OF ABUSE AND DEPENDENCE 53 Howard D. Cappell, Edward M. Sellers, and Usoa Busto 1."

As new faculty members in the Section of Psychiatry and Human Behavior at Brown University, we began collaborating on research into assessment and treatment of sexual problems in the fall of 1975. Although each of us arrived with clinical and research in terests in the broad field of sexual problems, the idea for this book grew out of our early discussions and a consensus on the future direction of research. We noted that there had been an extremely rapid increase in knowledge of human sexual behavior as well as sexual disorders and their treatment over the last few decades. It has also become increasingly apparent that sexual problems, broadly conceived, comprise a sizable fraction of the problems for which people seek treatment, and that, although the treatment of sexual problems was achieving some success, treatment was for the most part slow, costly, and without any guarantee of successful outcome. Furthermore, there were many people with sexual prob lems for whom treatment was not available. With these ideas in mind, it seemed timely for investigators in the field of human sex uality and its disorders to turn their attention to the problem of prevention. Organizing a symposium on the topic enabled us to invite leading investigators in the study of sexual behavior to address this area. The chapters in this volume are an outgrowth and refinement of the formal papers delivered at the symposium, which was held in the spring of 1976."

Other books in this series focus on behavior at the individual level, approached from the viewpoints of biochemistry, anatomy, physiology, and psychology. In this volume we show how the functioning nervous systems of interacting individuals are coordinated, with the ultimate creation of complex social structures. The intri cacies of an individual's nervous system have been subject to intense inquiry, and research at the chemical, cellular, and organ levels has made remarkable progress. Work at the social level has been conducted somewhat independently, by way of behavioral phenomena and communicative interactions. With the emergence of a large body of information from neurobiology, the beginnings of an integrated approach are possible. New data on social functions are presented in the chapters to follow, and the forward-looking reader may wish to reflect on how they clarify understanding of interactions between two or more independent nervous systems. The outcome is harmonious social structure and improvement in the inclusive fitness of group-living individuals. We believe that there is in prospect a new way of looking at social function that will ultimately increase our understanding of the highest and most complex levels of neurobiology. The modern approach to the study of social behavior involves more than the recording of interactions between animals. Each individual brings to the process of social interaction the implications of its prior genetic and experiential history."

Why another textbook on the design of wood sets this book apart is its inclusion of "struc structures? In many years of teaching structural tural planning. " Most textbooks show only the design in wood, the authors have used virtually selection of member proportions or number of every textbook available, as well as using only connectors in a joint to satisfy a given, com a code and no textbook at all. The textbooks pletely defined situation. This book, on the used have included both the old and the rela other hand, shows the thinking process needed tively modem; some have been fairly good, but to determine whether or not the member is re in our opinion each has deficiencies. Some quired in the first place. Following this, the books have too few solved examples. Others spacing and continuity of the member are de omit important material or have an arrange cided, its loads are determined, and finally its ment making them difficult to use as formal shape and size are selected. teaching tools. By writing this book, we intend We believe that illustrating structural plan to correct such deficiencies. ning as well as detailed member and connec The prime purpose of this book is to serve as tion design is of considerable value in helping a classroom text for the engineering or archi the student make the transition from the often tecture student."

Considerable worldwide interest has arisen in recent years in the controlled use of enzymes as catalysts in industrial processing, analytical chemistry and medical therapy. This interest has genera ted the new interdisciplinary field of Enzyme Engineering, which includes both the scientific and technologic aspects of the produc tion, purification, immobilization, and application of enzymes in a variety of situations and reactor configurations. A series of Engineering Foundation conferences on Enzyme Engineering was initia ted to provide an international forum for the exchange of ideas and information over the entire range of this new field. The outstanding success of the first two conferences attests to the vigor and poten tial of this field to contribute significantly to a better under standing and resolution of some of the major problems faced by man kind. The first conference, which was held August 9-13, 1971, at Henniker, New Hampshire, U. S. A., aided significantly in molding the several traditional disciplines that interact to form the field of Enzyme Engineering. The conference was highly successful mainly because many of the key scientists and engineers from the several facets of Enzyme Engineering were brought together for the first time at a single residential meeting. The result was an exchange of ideas and "education" of one another in the pertinent principles of the diverse disciplines which contribute to this field. The second conference, held August 5-10, 1973, at Henniker, New Hampshire, U. S. A."

In less than 40 years teratology has grown from a little known discipline concerned with studies on the effects of a few physical and chemical stresses on developing fish, amphibians, and birds, to a discipline embracing a vast accumulation of literature on experimental studies in many animal forms and the results of intensive scrutiny of human development under varied conditions, as well. Emphasis has shifted from preoccupation with descrip tions of anatomical defects to concern about subtle and interacting causative factors, to searches for the early reactions to these at the cellular and subcellu lar levels, and to identification of abnormality in the chemical, the functional, and the ultrastructural realms. These changes in orientation have quite naturally made necessary the recruitment of concepts, methods, and expertise from other disciplines. Hence the foundations of teratology, which once were largely morphological, have extended into genetics, biochemistry, molecular biology, reproductive physiology, epidemiology, and several aspects of veteri nary and clinical medicine. It is not surprising that a student or new investigator approaching the field of teratology may feel some dismay when confronted with the confusing array of cross-disciplinary concepts and principles it encompasses today. One of the aims of this work is to introduce what the editors believe is a logical thread of continuity into a field that may be regarded by some as a welter of disordered information."

Writing a textbook on microbial genetics in about 200 pages was un doubtedly a difficult task, but I have been encouraged by the response from both students and lecturers to the first edition. The requirement for a second edition is also a measure of the need for such a book. My experience as a lecturer has shown that what is needed first is an intelligible framework which can be read in a reasonable period of time. Armed with these principles, a student can then go to reviews and the original literature with a reasonable chance of understanding the jargon and the details. Molecular genetics is now so well advanced that it is easy to lose track of the purpose of a set of experiments in the wealth of sequence data and complex interactions. I have therefore kept the same format for this edition with a well-illustrated text giving original papers, popular reviews, monographs and detailed reviews to enable the student to take the subject further as required."

This book deals with the organic chemistry of polymers which find technological use as adhesives, fibres, paints, plastics and rubbers. For the most part, only polymers which are of commercial significance are considered and the primary aim of the book is to relate theoretical aspects to industrial practice. The book is mainly intended for use by students in technical institutions and universities who are specializing in polymer science and by graduates who require an introduction to this field. Several excellent books have recently appeared dealing with the physical chemistry of polymers but the organic chemistry of polymers has not received so much attention. In recognition of this situation and because the two aspects of polymer chemistry are often taught separately, this book deals specifically with organic chemistry and topics of physical chemistry have been omitted. Also, in this way the book has been kept to a reasonable size. This is not to say that integration of the two areas of polymer science is undesirable; on the contrary, it is of the utmost importance that the inter-relationship should b~ appreciated. I wish to record my thanks to my colleagues with whom I have had many helpful discussions, particularly Mrs S. L. Radchenko. I also thank Miss E. Friesen for obtaining many books and articles on my behalf and Mr H. Harms for encouragement and assistance. I am also grateful to Mrs M. Stevens who skilfully prepared the manuscript. Department of Chemical and Metallurgical Technology, Ryerson Polytechnical Institute, K. J. S.

to the English edition Many processes that describe the operation of engineering, economic, organiza tional, and other systems are represented as sequences of operations performed on material, information, or other types of flows. Typical examples are processes of connection of telephone users, data transmission and processing, calculation at multi user computer centers, and queueing at service centers. The models studied by the theory of service systems, or queueing theory, are used to describe such processes. The more pessimistic term "queueing theory" is used more often in the non-Soviet literature. Random arrivals (requests for service), probability distributions defining queueing processes (distributions of service times and acceptable waiting times), and structure parameters (customer priorities, parameters that delimit acceptable queues, parameters that define paths of customers, etc.) are characteristic com ponents of queueing models. Typical output characteristics of queueing models are the probability distributions of queue lengths, waiting times, lengths of busy periods, and so forth."

Assembly of 'difficult' components onto printed circuit boards is emerging as an important application area for small, fast industrial robots. For other robot tasks - for example paint spraying or arc welding - the applications engineer can rely on a body of published information representing decades of accumulated knowledge about the actual process being automated. But for the process of assembly relatively little systematically presented knowledge exists, mainly because so much manual assembly depends on extremely subtle co-ordination of hand, eye and brain which is hard to represent directly in engineering terms. As for the particular processes of electronic assembly, they have hardly been covered at all in the literature. Yet the design of a good PCB automation system depends crucially on the responsible engineer fully understanding every aspect of the process he or she is automating, whether working for the electronics manufacturer, an automation company, a research laboratory or a machine builder. The author of this book has had extensive practical experience in all these roles: as a source of great detail on most aspects of the electronic assembly process it will be of unique value not only to the robot specialist but well beyond that to anyone needing to understand how printed circuit boards are manufactured. P. G. Davey Acknowledgements The author is indebted to many companies and individuals from within the pcb assembly industry.

Hardly a decade ago, membrane receptors were an attractive but largely unproven concept. Since that time enormous progress has been made, and we are now able to consider receptors much more concretely. Their existence has been established, their binding properties have been determined, and in some cases, they have been highly purified and their physical-chemical properties studied. It is now even possible to visualize microscopically some receptors. This progress has resulted largely from the development of highly powerful methods. These methods are the subject of this volume. Although considerably diverse, different receptors share certain common pro perties, and common problems are encountered in their study. Consequently, a small number of techniques are particularly useful in studying different types of receptors. Thus, it makes sense to speak about membrane receptor methodology. A very apparent problem in the study of membrane receptors is their presence in exceedingly small quantities and in a highly impure state. Therefore, very sensitive and specific techniques are required for their detection, characterization and purification. Such sensitivity and specificity is provided by the ability of receptors to bind certain ligands with very high affmity, and it is not surprising that most of the methods described in this volume depend upon this high affinity binding. The antigen-antibody interaction is of comparable sensitivity and speci ficity. Recently, a number of anti-receptor antibodies have been produced or found to occur spontaneously in auto-immune diseases. Undoubtedly, more will be produced in the future."

Great advances have been made in the area of sensory physiology during the last few decades, and these developments seem to be asking for a comprehensive review that is manageable in size and cohesive in content. This volume has been written with that goal in mind. In the first place I would like to thank Mr. R. van Frank of Appleton-Century-Crofts for asking me to do the job, and my wife for persuading me to do it, for writing it was an enjoyable task. Much of the discussion of factual data set to print here evolved in question-and-answer sessions in courses given to students in physiology, psychology, and medicine, and to physicians training in neurology, neurosur gery, and psychiatry. Besides my students, I had in mind while preparing this text my professional colleagues laboring on their lecture notes under circum stances perhaps not unlike my own. The material is divided in two parts. The first deals with the manner of representation of sensory information in peripheral nerves: the so-called first order code. The second half of the text deals with the handling of sense data by the central nervous system. One reason for dividing the material in this way is that many of the features of the first-order code are common to all sensory modalities. The intensity, the place, the rhythm, the "quality" of stimuli are encoded by rules which are applicable, albeit with appropriate modifications, to all senses. Furthermore, these rules of coding are today rather well understood."

All animals, from protozoans to primates, utilize energy in every aspect of their lives. Metabolic processes transform energy within the living cells. Individual animals obtain energy with their food and use it in a variety of ways. Populations and communities pass energy through their ecosystem. The growing interest in animal energetics is therefore seen in three major areas of zoology-biochemistry, physiology and ecology. We have tried to describe the main features of almost all these aspects, with the aim of arousing or feeding an interest in energetics in general as well as supplying some information on particular parts of the subject. The substantial list of references is intended to guide the reader to larger or more specialized works. In covering such a wide field in so small a compass we will have been guilty of over-generalizations, but we find when teaching energetics, whether physiological or ecological, that students easily lose sight of the principles if all statements are hedged about with every relevant condition and exception. We have drawn examples from a wide range of animals, avoiding over-emphasis on mammals, but we have tended to favour those groups with which we are more familiar. We are grateful to many people for helpful discussions and in particular to Kenneth Denbigh, Derek Miller and John Stirling for valuable criticisms of parts of the manuscript. We are responsible for all remaining errors, of course, and will welcome having them drawn to our notice. A.E.B. M.J.L.