Recent advances in the understanding of the major events that shape the immune recog nition system have been remarkable. The analysis of immunoglobulin (Ig) gene organization and Ig repertoire diversification in lower vertebrates has provided new insight into this process in mammals. Similarly, the understanding of the early development of lymphocytes and of the acquisition of immunological tolerance has been aided by elegant studies in quail/chicken chimeras, using the power of the distinctive markers of the constitutive cells of these birds. Great strides have been made in understanding the role played by major histocompatibility complex (MHC) molecules in antigen presentation and in repertoire selec tion within the thymus. The use of transgenic mice expressing specific T-cell receptor (TCR) genes has elucidated the process of both positive and negative selection. In parallel, there has been considerable progress in our understanding of tolerance, based in part on the use of markers for the V fJ genes of T-cell receptors and in part on the analysis of the behavior of long term T-cell lines. This has led to the realization that both clonal deletion and clonal anergy may play critical roles in the maintenance of unresponsiveness to self antigen. Molecular analysis of the requirements for expression of membrane immunoglobulin molecules has revealed the existence of a complex that appears to be of critical importance in mediating signalling through Ig receptors. In addition, major insights have been obtained into the regulation of expression of genes of immunologic interest.

In 1974 when I published my book, Biological Mechanism of Attachment, not many pages were required to report on the attachment devices of insect cuticles. As in most fields of research, our knowledge on this specific subject has simply exploded. Dr. Stanislav N. Gorb now describes the present day level of our knowledge, to which he has personally contributed so much, and a research team working on biological microtribology has gradually developed, also. With modern methods of measurement it is possible to enter the structure - function relationship much more deeply, even down to a molecular level, which was not possible two and a half decades ago. It is a well known fact that, in biology, the more sophisticated the measuring method, the greater the achievement of biological fundamental research, and its resulting evidence. Our knowledge remains at a certain level until new methods once more permit a forward leap. Biological knowledge develops in the form of a stepped curve rather than linear, as reflected in the studies carried out on the attachment devices of insect cuticles.

Recent years have seen great strides in research on the pathogenesis of thromboses, unmatched by progress in other branches of hemostasiology. The orthodox concepts of the mechanisms of thrombus formation described by Virchow have come down to us as a "classical triad" of factors. Now, due to developments in molecular biology, pharmacology, and patho- physiology, they appear in a basically new light. The fruits of modern research, currently being tested or already imple- mented in clinical practice, have opened up the possibility of controlling the hemostatic process and developing effec- tive antithrombotic drugs. Much progress has been achieved in the past years, but much more remains to be achieved in such areas as the patho- genesis of venous and arterial thromboses, early diagnosis, therapy, and control of disorders. Many scientists in the U.S.S.R. are involved in studying these problems. Their data, from years of research carried out in leading laboratories and clinics in the U.S.S.R., are summarized in this monograph. This work is written by experts in various fields of biology and medicine. It deals with new and original con- cepts on the structure and function of the fibrinolytic sys- tem, the role of nonenzymatic fibrinolysis in regulating physiological hemostasis, the heterogeneous and discrete pat- terns of the system regulating blood coagulation, the molecu- lar mechanisms of fibrin polymerization, and the anticoagu- lating effects of fibrinogen/fibrin degradation products.

This book is a compilation of the lectures and oral and poster communications presented at the Advanced Study. Institute on "Vascular Endothelium: Physiological Basis of Clinical Problems II," which took place between June 20 and 30, 1992 in Rhodes, Greece. This third in a series of ASIs on vascular endothelium continued on the theme of the first (1988) ASI on "Receptors and Transduction Mechanisms" and particularly expanded that of the 1990 conference on ''Physiological Basis of Clinical Problems. " We continued the successful practice of bringing together clinicians and scientists: this was reflected equally well in the composition of the organizing committee as in the background of the particiJ?ants. Endothelial cell functions and dysfunctions present as many challenges to the mvestigator as they do to the curious clinical practitioner. As these problems are necessarily different, this unique ten-day co-habitation of these individuals continued to offer fresh outlooks to each, stimulated potential collaborative efforts and, most importantly, advanced --ever so slightly--our knowledge of vascular biology. This year's conference was further enriched by the presence of several of our colleagues from Eastern Europe whom we are delighted to welcome as officially sponsored participants to this and future NATO-supported meetings. It is never superfluous to remind readers and participants that those signing at the bottom of this page, while responsible for many of the ASI's and the book's deficiencies, are but three of the many contributors to the successes.

If this were a traditional textbook of neuroanatomy, many pages would be devoted to a description of the ascending and descending pathways of the spinal cord and several chapters to the organization of the sensory and motor systems, and, perhaps, a detailed discussion of the neurological deficits that follow various types of damage to the nervous system would also be included. But in the first draft of this book, the spinal cord was mentioned only once (in a figure caption of Chapter 2) in order to illustrate the meaning of longitudinal and cross sections. Later, it was decided that even this cursory treatment of the spinal cord went beyond the scope of this text, and a carrot was substituted as the model. The organization of the sensory and motor systems and of the peripheral nervous system have received similar coverage. Thus, this is not a traditional text, and as a potential reader, you may be led to ask, "What's in this book for me?" This book is directed primarily toward those students of behavior who are either bored or frightened by the medically oriented texts that are replete with clinical signs, confusing terminology, and prolix descriptions of the human brain, an organ which is never actually seen in their laboratories. I should hasten to add, however, that this text may also serve some purpose for those who read and perhaps even enjoy the traditional texts.

In the last decade, research on platelet-activating factor (PAF) has expanded exponentially. Previous conferences on PAF in Paris, 1983, and the subsequent conferences in Gatlinburg, Ten nessee, Tokyo, Snowbird, Utah, and Berlin, at three-yearly intervals, have chronicled the devel opments in the field ofPAF. This volume records the proceedings of the Fifth International Con gress on PAF and Related Lipid Mediators, held at the Free University Medical Hospital Ben jamin Franklin in Berlin, from September 12-16, 1995. We are very much indebted to Free Uni versity Berlin for providing tremendous facilities and financial support. It was a great pleasure to have positive and generous input from the German Science Council (DFG), Bonn, Germany, and British.Biotech, Oxford, United Kingdom. Their support was crucial in making the congress a scientific success. Twenty other organizations provided additional financial support, for which we extend our deepest appreciation. The editors would like to thank all of those who participated in this congress and the authors for their contributions. The organization and planning of the Berlin Congress were carried out by an organizing committee. We gratefully acknowledge the support and assistance of the organizing commit tee members, especially Renate Nigam and Renate Roux for their untiring efforts to make the congress successful. Many colleagues also supported the congress with dedication, hard work, and expert input. We are grateful to them. We also wish to acknowledge the support of G. Sravan Kumar and Louis Kock for their efforts in producing this volume."

Fishes are very successful vertebrates and have adapted to a wide range of environmental conditions, from the deep ocean to the smallest brook or pond. The physiological background to these environmental adaptations is, obviously, far from clear, and provides fish physiologists with many challenges. The number of extant fish species has been estimated to be in excess of 20000, and only relatively few of these have been subject to physiological studies. Yet among these animals can be found many physiological systems different from those of the land-dwelling vertebrates, and also systems similar to those of the 'higher' vertebrates but at a different level of phylogenetic development. Apart from the rapidly increasing interest in basic fish physi ology, the last few years have seen a dramatic increase in applied research, aimed primarily in two directions: fish culture and envi ronmental toxicology. Physiological research is of vital importance in both these fields, and basic fish physiology is a necessary base for the applied research. This book is intended for a wide readership among senior undergraduate, postgraduate and research students, as well as uni versity teachers and researchers in zoology, physiology, aqua culture and biology generally. The book focuses on five major areas of basic and applied research: haemopoiesis, acid-base regu lation, circulation, gastro-intestinal functions and physiological toxicology. The chapters will serve as introductions to these fields, as well as up-to-date reviews of the most recent advances in the research areas."

A number of factors have come together in the last couple of decades to define the emerging interdisciplinary field of structural molecular biology. First, there has been the considerable growth in our ability to obtain atomic-resolution structural data for biological molecules in general, and proteins in particular. This is a result of advances in technique, both in x-ray crystallography, driven by the development of electronic detectors and of synchrotron radiation x-ray sources, and by the development ofNMR techniques which allow for inference of a three-dimensional structure of a protein in solution. Second, there has been the enormous development of techniques in DNA engineering which makes it possible to isolate and clone specific molecules of interest in sufficient quantities to enable structural measurements. In addition, the ability to mutate a given amino acid sequence at will has led to a new branch of biochemistry in which quantitative measurements can be made assessing the influence of a given amino acid on the function of a biological molecule. A third factor, resulting from the exponential increase in computing power available to researchers, has been the emergence of a growing body of people who can take the structural data and use it to build atomic-scale models of biomolecules in order to try and simulate their motions in an aqueous environment, thus helping to provide answers to one of the most basic questions of molecular biology: the relation of structure to function.

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."

Writers on arthropod water relationships range from bio physicists and biochemists to population ecologists-a fact that gives cause to wonder whether the field is already too heterogeneous to be written about in a single book by a single author. I have partly avoided the problem by concentrating largely on physiological mechanisms and by omitting most aspects of behavioural regulation and most aspects of heat balance and body temperature, except when these impinge directly on water balance. Even within this limited field there has been a lot of work during the past twenty years, as a result of which some problems have been solved (or at least more clearly defined), and many others have been opened up. On the whole there has been a welcome change to a more rigorous experimental approach and it is now possible for water balance people to state their problems in physiological terms. Good progress has been made towards understanding the mechanisms involved in nearly all avenues of water uptake and loss, although problems indeed remain. The cuticle has yielded part of its secrets to electron micrography, but ex ploration by means oflipid biochemistry among other techniques is necessary for a real understanding of cuticle permeability."

During the past few decades, much research has been reported on the formation of insoluble monomolecular films of lipids and biopolymers (synthetic polymers and proteins) on the surface of water or at the oil-water interface. This interest arises from the fact that monomolecular film studies have been found to provide much useful information on a molecular scale, information that is useful for understanding many industrial and biological phenomena in chemical, agricultural, pharmaceutical, medical, and food science applications. For instance, information obtained from lipid monolayer studies has been useful in determining the forces that are known to stabilize emulsions and biological cell membranes. The current texts on surface chemistry generally devote a single chapter to the characteristics of spread monolayers of lipids and biopolymers on liquids, and a researcher may have to review several hundred references to determine the procedures needed to investigate or analyze a particular phenomenon. Furthermore, there is an urgent need at this stage for a text that discusses the state of the art regarding the surface pheqomena exhibited by lipids and biopolymers, as they are relevant to a wide variety of surface and interfacial processes.

Fluorescence microscopy images can be easily integrated into current video and computer image processing systems. People like visual observation; they like to watch a television or computer screen, and fluorescence techniques are thus becoming more and more popular. Since true in vivo experiments are simple to perform, samples can be directly seen and there is always the possibility of manipulating the samples during the experiments; it is an ideal technique for biology and medicine. Images are obtained by a classical (now called wide-field) fluorescence microscope, a confocal scanning microscope, upright or inverted, with epifluorescence or transmission. Computerized image processing may improve definition, and remove glare and scattered light signal. It also makes it possible to compute ratio images (ratio imaging both in excitation and in emission) or lifetime imaging. Image analysis programs may supply a great deal of additional data of various types, starting with calculations of the number of fluorescent objects, their shapes, brightness, etc. Fluorescence microscopy data may be complemented by classical measurement in the cuvette yr by flow cytometry.

Amino acid transport is a part of each of two larger subjects, amino acid metabolism and the biomembrane transport of various . small molecules and ions. Nevertheless in this volume we treat amino acid transport as more than a fragment of either of these two larger subjects. A more comprehensive approach is justified when we remember two historic and ongoing aspects of the title subject. First, amino acid transport had its beginning and acquired a distinct momentum (even if somewhat interrupted from 1913 until about 1945) as amino acid metabolism with the central and pioneer work of Van Slyke and Meyer in 1913. The reviews in this volume will show that it steadily becomes a larger aspect of amino acid metabolism, broadly perceived. These chapters will show for how many organelles, cells, tissues, organs and organ systems, the transmembrane compartmentations and flows of amino acids play very large parts in their fundamental biological relations. The authors here are tending collectively to evaluate an understanding of amino acid flows across biomernbranes, and the regulation of these flows, as necessary to an ultimate understanding of the full range of development and metabolism. Such an understanding goes far beyond the purely substrate-destabilizing contributions by enzymes, which have often been arbitrarily limited to that conceptual entity, "the cell," and which for so long a splendid time had most of biochemical research attention.

This volume describes the current state of our knowledge on the neurobiology of muscle fatigue, with consideration also given to selected integrative cardiorespiratory mechanisms. Our charge to the authors of the various chapters was twofold: to provide a systematic review of the topic that could serve as a balanced reference text for practicing health-care professionals, teaching faculty, and pre-and postdoctoral trainees in the biomedi cal sciences; and to stimulate further experimental and theoretical work on neurobiology. Key issues are addressed in nine interrelated areas: fatigue of single muscle fibers, fatigue at the neuromuscular junction, fatigue of single motor units, metabolic fatigue studied with nuclear magnetic resonance, fatigue of the segmental motor system, fatigue involving suprasegmental mechanisms, the task dependency of fatigue mechanisms, integrative (largely cardiorespiratory) systems issues, and fatigue of adapted systems (due to aging, under-and overuse, and pathophysiology). The product is a volume that provides compre of processes that operate from the forebrain to the contractile proteins.

The symposium on "Zinc in Soils and Plants" is the third in a series which began with "Copper in Soils and Plants" in Perth in 1981 and continued with "Manganese in Soils and Plants" in Adelaide in 1988. The symP9sium brings together a series of valuable accounts of many aspects of the reactions of zinc in soils, the uptake, transport and utilization of zinc in plants, the diagnosis and correction of zinc deficiency in plants and the role of zinc in animal and human nutrition. I am grateful for the financial support provided by Grains Research and Development Corporation, Rural Industries Research and Development Corporation, Wool Research and Development Corporation, Ansett Australia, and Qantas Australian. I am most appreciative of the willingness of many scientists to act as referees: G S P Ritchie, R J Gilkes, N C Uren, K Tiller, BLeach, H Greenway, N E Longnecker, J F Loneragan, Z Rengel, C A Atkins, J W Gartrell, P J Randall, D G Edwards, R J Hannam, R J Moir, J E Dreosti, N Suttle, C L White, H Marschner, N Wilhelm, M McBride. All provided valuable comments on the manuscripts. Finally, I thank Mrs M Davison who provided excellent secretarial assistance. A.D. Robson September 1993 Chapter 1.

This book describes in general how the chemosensory systems of fish function at various levels. In many ways, fish are typical vertebrates differing only slightly from other vertebrates including humans. In other ways, their aquatic environment imposes strict requirements or offers unique opportunities which have resulted in some unusual functions having no counterpart in higher vertebrates. This new volume is necessitated by advances in many vital areas as the field of chemical senses continues to grow at a rapid pace. Most significant is the application of the contemporary electrophysiological technique of patch-clamping, recognition of a second messenger system in chemosensory transduction processes and the identification of hormonal pheromones in fish reproductive behaviour. The last major synthesis of our knowledge about fish chemoreception, Chemoreception in Fishes, was published ten years ago (Elsevier, Amsterdam, 1982). In that volume four aspects of fish chemoreception, Le. morphology of the peripheral chemoreceptors. primary sensory processes, roles in behaviour, and its interactions with environment, were discussed. This book is intended to be helpful to students, scientists and aquacul turists not only as a source book but also as a textbook on chemical senses."

Methods in Bone Biology is unique in being devoted to describing the methodology used by bone researchers. This book describes in detail the techniques of cell and organ culture used in the study of bone and bone cell function and the techniques used to monitor the skeleton and skeletal remodelling both in clinical and experimental settings.

Charles E. Hess Department of Environmental Horticulture University of California Davis, CA 95616 Research in the biology of adventitious root formation has a special place in science. It provides an excellent forum in which to pursue fundamental research on the regulation of plant growth and development. At the same time the results of the research have been quickly applied by commercial plant propagators, agronomists, foresters and horticulturists (see the chapter by Kovar and Kuchenbuch, by Ritchie, and by Davies and coworkers in this volume). In an era when there is great interest in speeding technology transfer, the experiences gained in research in adventitious root formation may provide useful examples for other areas of science. Interaction between the fundamental and the applied have been and continue to be facilitated by the establishment, in 1951, of the Plant Propagators' Society, which has evolved into the International Plant Propagators' Society, with active programs in six regions around the world. It is a unique organization which brings together researchers in universities, botanical gardens and arboreta, and commercial plant propagators. In this synergistic environment new knowledge is rapidly transferred and new ideas for fundamental research evolve from the presentations and discussions by experienced plant propagators. In the past 50 years, based on research related to the biology of adventitious root formation, advances in plant propagation have been made on two major fronts.

Electric currents and electromagnetic fields have been applied to biological systems, particularly humans, with both therapeutic and pathological results. This text discusses biological responses to electric currents and electromagnetic fields, including medical applications and shock hazards. It covers fundamental physical and engineering principles of responses to short-term electrical exposure and emphasises human reactions, although animal responses are considered as well, and the treatment covers reactions from the just-detectable to the clearly detrimental. An important new chapter discusses standards for human exposure to electromagnetic fields and electric current and demonstrates how these standards have been developed using the principles treated in earlier chapters.

Photobiology - the science of light and life - begins with basic principles and the physics of light and continues with general photobiological research methods, such as generation of light, measurement of light, and action spectroscopy. In an interdisciplinary way, it then treats how organisms tune their pigments and structures to the wavelength components of light, and how light is registered by organisms. Then follow various examples of photobiological phenomena: the design of the compound eye in relation to the properties of light, phototoxicity, photobiology of the human skin and of vitamin D, photomorphogenesis, photoperiodism, the setting of the biological clock by light, and bioluminescence. A final chapter is devoted to teaching experiments and demonstrations in photobiology.
This book encompasses topics from a diverse array of traditional disciplines: physics, biochemistry, medicine, zoology, botany, microbiology, etc., and makes different aspects of photobiology accessible to experts in all these areas as well as to the novice. It is intended primarily for graduate students and for researchers who wish to look outside their speciality, but can also act as a source of information for undergraduate students.

This book will give an overview of insect ovaries, showing the diversities and the common traits in egg growth processes. The idea to write this book developed while looking at the flood of information which appeared in the early 1980s on early pattern formation in Drosophila embryos. At this time a significant breakthrough was made in studies of this little fly, combining molecular biological methods with classical and molecular genetics. The answers to questions about early pattern formation raised new questions about the architecture of ovaries and the growth of eggs within these ovaries. However, by concentrating only on Drosophila it is not possible to form an adequate picture of what is going on in insect ovaries, since the enormous diversity found among insects is not considered sufficiently. Almost forgotten, but the first to study the architecture of ovaries, was Alexander Brandt writing in 1878 in aber das Ei und seine Bildungsstaette (On the egg and its organ of development). More than 100 years later, a series of ten books or more would be required to survey all the serious informa tion we have today on insect oogenesis. Thus, this book is a personal selection and personal view on the theme, and the authors must be excused by all those scientists whose papers could not be included. The book briefly describes the ectodemes, i. e."

This book is dedicated to the memory of two colleagues and friends, Amico Big- nami and Hendrick Vander Los. They were both pioneers in their fields: Bignami on on- togenesis and function of neuroglia, and Van der Los on brain plasticity and neuronal circuitry. Their ideas are further pursued by the authors in this book. Some of the chapters are products of a conference dedicated to these two scientists entitled "Recent Advances in Neurobiology: Plasticity and Regeneration." The conference was organized by the Insti- tute of Developmental Neuroscience and Aging and sponsored by the Region della Valle d' Aosta. Also, several chapters are written by colleagues who knew well either Amico or Hendrick and were invited to contribute to this dedication. The book is divided in four sections. The first part covers neurons, neuroglia includ- ing microglia, their plasticity and phenotypic expression, and specific functions and inter- actions. It is now established that neuroglia are an intimate component of the neuronal environment and thought to regulate several neuronal functions. More recently microglia have become prominent as the immune cells in the CNS. This part contributes new infor- mation for these cellular interactions. The second part deals with neuronal and glial cell plasticity as it relates to regeneration and neurodegeneration, more or less an extension of Part I. In recent years the role of transplantation in regeneration has become promising.

Reproduction is the origination of new organisms from pre-existing ones. Among more than 35 separated forms of reproduction including several types of gamogony, parthenogenesis, agamogenesis, fission and division, and plas motomy, the bisexual mode of reproduction via fertilization provides genetic variability that allows species to adapt quickly to competitive and constantly changing environments. Several excellent reviews and books have been written in the past to analyse the mechanisms of fertilization in different eukaryotic species. During the last few years, however, renewed attention has been paid to examining the process of oocyte fertilization at the cellular/molecular level not only within a single species/group but also through different phylogenetic lineages. As a result of this effort, knowledge of the molecular pathways used by oocytes and spermatozoa at fertilization has increased, but still many ques tions remain to be answered. Being aware of the necessity of providing an inte grated view of the process of fertilization, this book has been entirely devoted to reviewing the process of oocyte fertilization at the cellular/molecular level in two different and separated groups of eukaryotic organisms: protozoa and metazoan animals. The book is organized into six sections dealing with oocyte fertilization in protozoa, invertebrates, teleost fishes, amphibians, birds and mammals. These sections are followed by a summary/concluding chapter that provides a com parative overview of the process of fertilization in these groups of eukaryotes."

Providing a survey on current research in eukaryotic signal transduction, some of the topics covered are, the biochemistry and biophysics of cell surface receptors, G-protein mediated signalling pathways, regulation of cyclic AMP, Ca2+, inositol phosphate pathways, the structure and regulation of receptors which are tyrosine protein kinases, and cellular responses to integrated signals.

Though it is a pleasure to write a short foreword to this collection of excellent scientific papers covering a range of biological topics, the rather depressing feature is the small number of papers. All-electronic publishing is developing and your Editors do have great faith in it. One problem for potential authors has been the reluctance of the abstracting journals to pay any attention to electronic journals - perhaps Springer should make a rapid move in this area and start the first all-electronic journal abstracting this type of literature. However, even the paper citation journals are starting to pay attention to the medium. The particular advantages of all-electronic publishing are beginning to emerge more clearly and it is clear that publishing video material is a unique advantage of our format. Several papers took advantage of this - for example those by Riehle and others on cell behaviour in tunnels, by Bereiter-Hahn and Voss on zonation in the plasmalemma and by Pavlikova, Zicha, Chaloupkova and Vesely on cell motility of tumour cells. These papers made essential and extensive use of video material, publishing some material of great originality. The work on cell pola rity and calcium ions in Fucus embryos by Brownlee, Manison and Anning used animation to present their results in an especially clear way. The facility of use of animation is another special advantage of our type of publication that should be more widely used."