The German Society of Cybernetics organizes international conferences on selected interdisciplinary topics in regular 3-year intervals. The aim of these meetings is to bring together scientists who work in quite different disciplines, but are confronted with related problems and use the same or similar approaches. The topic of the 1983 conference which was held on March 23-25 at the University of Tiibingen came from a typical field of research in which engineers, biologists, and phYSicists share a common interest. We do not want to discuss here in detail the common principles which are used by nature and by engineers to solve the problems associated with localization and orientation, since the reader will find enough examples in this volume. The question, however, whether the participants of such meetings can really profit from each other, deserves some further consid eration. First, there is the difficulty of finding a common language. This still seems to be a problem, although in some fields the language of engineers and biologists has become very similar over the years, an impression we also gained during the conference. Most of the authors made a great ef fort to use a vocabulary which is understandable to people outside their own field of research, but, admittedly, not all succeeded."

Radiation induces a variety of chemical processes in biological tissues. This volume is a synthesis of up-to-the-minute reviews on such photochemical and photobiological sensitized reactions with particular relevance to photomedicine. The first part gives a description of experimental techniques for the study of the primary processes after radiation absorption by biological systems. It is followed by chapters on singlet oxygen and photomedicine, considering both phototherapy and photochemotherapy. These sections also discuss the next generation of potential photosensitizing drugs.

Medical applications of ultrasound range from therapy, foetal monitoring, diagnostic imaging and blood flow measurement, to surgery and lithotripsy. Ever since the earliest developments of medical ultrasound there has been an interest in the measurement and characterisation of the ultrasonic fields generated in these applications, either for assessment of performance of equipment or for safety. Until recently, procedures for acoustic output measurements were ill-defined, but standards are now being developed internationally by the International Electrotechnical Commission (1EC) and reliable commercial measuring equipment is becoming more widely available. The aim of this book is to introduce acoustic output measurement techniques and to provide an insight into the measurement methods. The material presented is based on a course originally run during November 1989 at the National Physical Laboratory. In addition to the lectures, the course consisted of a series of practicals to allow participants to gain experience of making measurements. Teddington, UK Roy C. Preston February 1991 Contents List of Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii List of Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 Safety of Diagnostic Ultrasonic Equipment: The Relevance of Acoustic Output Information to the Clinical User R. C. Preston 1. 1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1. 2 The Relevance of Acoustic Output Information. . . . . . . . . . . . . 6 1. 2. 1 What Is Acoustic Output Information? . . . . . . . . . . . . . . . . . . . 6 1. 2. 2 What Is Acoustic Output Information Used For? . . . . . . . 6 1. 2. 3 Why Should You Know the Acoustic Output Levels of Your Equipment? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1. 2. 4 Are Acoustic Output Levels Really that Important? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

This book is based on research carried out by the author in close collabora- tion with a number of colleagues. In particular, I wish to thank Per Bak, A. John Berlinsky, Hans C. Fogedby, Barry Frank, S. 1. Knak Jensen, David Mukamel, David Pink, and Martin Zuckermann for fruitful and extremely stimulating cooperation. It is a pleasure for me to note that active interaction with most of these colleagues is still continuing. The work has been performed at several different institutions, notably the Department of Chemistry, Aarhus University, Denmark, and the Depart- ment of Physics, University of British Columb~a, Canada. I wish to thank the Department of Chemistry at Aarhus University for providing me with splen- did research facilities over the years. From May 1980 to August 1981, I visited the Department of Physics at the University of British Columbia and I would like to express my sincere gratitude to members ofthe department for provi- ding me with excellent working conditions. My special thanks are due to Professor Myer Bloom who introduced me to the field of phase transitions in biological membranes and in whose biomembrane group I found an extre- mely stimulating scientific atmosphere happily married with a most agreeable social climate. During the last two years when a major part ofthis work was carried out, I was supported by AlS De Danske Spritfabrikker through their Jubilreumsle- gat of 1981. Their support is gratefully acknowledged.

This volume deals with the significance of the apoblast and the intracellular matrix in cell to cell signaling in plants and animals. Researchers working on human, animal and plant systems discuss their own specific problems. The dynamics of the cell surface as related to both growth and development, as well as to the transduction of environmental signals and the feed-back from genetic information to the cell surface are comprehensively covered. Special emphasis is laid on experimental models, their applicability and discussion of possible directions for future research.

The contents of this volume derive loosely from an EMBO worksh9P held at EMBL (Heidelberg) towards the end of 1989. The topic of Patterns in Protein Sequence and Structure attracted a wide range of participants, from biochemists to computer scientists, and that diversity has, to some extent, remained in the contributions to this volume. The problems of interpreting biological sequence data are to an increasing extent forcing molecular biologists to learn the language of computers, including at times, even the abstruse language of the computer scientists themselves. While, on their side, the computer scientists have discovered a veritable honey-pot of real data on which to test their algorithms. This enforced meeting of two otherwise alien fields has resulted in some difficulties in communication and it was an aim of the EMBO workshop to help resolve these. By the end, most biologists at the meeting had, at least, heard the terms Dynamic Programming and Regular Expression while for their part the computer programmers began to realise that protein sequences might be more than simple Markov chains in a 20-letter alphabet. Thanks to the modern facilities at EMBL, the three day meeting was video-taped and from this a transcript was taken and offered to the speakers as the basis for a contribution to this volume.

Four years ago The Blue Light Syndrome was published as the Proceed ings of the 1 st International Conference on the Effect of Blue Light in Plants and Microorganisms. Subsequently the interest in this fascinating and growing field of re search has further increased, as is reflected by numerous publications. Blue light effects cover such a wide spectrum of organisms, responses and methods that communication among scientists with backgrounds in biology, biochemistry, and biophysics is particularly necessary. These facts not only justified, but demanded calling the "Blue Light Family" together again. In spite of many fmancial problems, the second confer ence attracted 113 active members from 19 countries. The 2nd International Conference on The Effect of Blue Light in Plants and Microorganisms was held in July 1984, like the first at the University of Marburg. The organizer could again rely on the help of the International Advisory Committee (W. Briggs, Stanford; M. Furuya, Tokyo; J. Gressel, Rehovot; S. Miyachi, Tokyo; W. Rau, Miinchen; J. Schiff, Waltham; P .-S. Song, Lubbock). The very generous financial as sistance from the DFG and the support of the Philipps-Universitat Mar burg and its Sonderforschungsbereich "Zellenergetik and Zelldifferen zierung" were the prerequisites to organizing the conference. The present book consists of 56 original papers. The partitioning into eight chapters is always a problem. The grouping of different aspects of the papers into these chapters has not always been obvious, so that one or the other contribution could possibly fit in another chapter."

Markedly apart from elementary particle physics, another current has been building up and cont i nuous ly growi ng within contemporary phys i cs for severa 1 decades, and even expanding into many other disciplines, especially chemistry, biology and, quite recently, economics. Several reasons account for this: presumably the most impor- tant one lies in the fact that, whatever the specific problem, model or material concerned, the same basic mathematical features are always involved. In this way, a general phenomenology has emerged which, unlike thermodynamics, is no longer depen- dent upon the details or specifics: what largely prevails is the nonlinear charac- ter of the underlying dynamics. Perhaps we are witnessing the emergence of a "non- linear physics" - in a way similar to the birth of "quantum physics" in the twen- ties - a physics which deals with the general behaviour of systems, whatever they are or may be. Over the past fifteen years, chemical systems evolving sufficiently far from equilibrium have proved to be particularly well fitted to experimental research on nonlinear behaviour: oscillation, multistability, birhythmicity, chaotic evolution, spatial self-organization and hysteresis are displayed by chemical reactions whose number is growing each year. In this volume are collected the lectures, communica- tions and posters (abstracts) presented at an international meeting entitled: "Non-Equilibrium Dynamics in Chemical Systems", held in Bordeaux (France), Septem- ber 3 rd-lth, 1984.

Lasers in Dermatology presents an excellent and complete survey of the numerous applications of lasers in dermatological therapy and research, the fundamentals of laser-skin interaction, and the various laser sources and tools in use. A comprehensive outlook to new instrumentation, such as pulsed lasers of ultraviolet and infrared wavelengths, completes this up-to-date overview, which is indispensable not only to practitioners and clinical researchers in dermatology but also to engineers and laser physicists in biomedicine.

Computational techniques have become an indispensable part of Molecular Biology, Biochemistry, and Molecular Design. In conjunction with refined experimental methods and powerful hardware, they enable us to analyze and visualize biomolecular structures, simulate their motions and to a variable degree understand their physicochemical properties and function. In addition, they provide essentially the only way to analyze and correlate the astronomical amounts of experimental sequence and structural data accumulating in international databases. We have good reasons to believe that further advances in this area will eventually enable us to predict with sufficient accuracy many structural and functional properties of fairly large biomolecules, given their sequence and specified environmental conditions. However, it is also important to realize that in achieving this goal, we encounter several serious problems of conceptual and methodological nature, the solution of which requires new approaches and algorithms. For example, we need better force fields, more efficient optimization routines, an adequate description of electrostatics and hydration, reliable methods to compute free energies, and ways to extent the length of molecular dynamics simulations by several orders of magnitude.

This book is more than a standard proceedings volume, although it is an almost direct result of the workshop on "Nonlinear Analysis of Physiologi cal Time Series" held in Freital near Dresden, Germany, in October 1995. The idea of the meeting was, as for previous meetings devoted to related topics, such as the conference on dynamical diseases held near Montreal in February 1994 (see CHAOS Vol. 5(1), 1995), to bring together experts on the techniques of nonlinear analysis and the theory of chaos and applicants from the most fascinating field where such methods could potentially be useful: the life sciences. The former group consisted mainly of physicists and mathe maticians, the latter was represented by physiologists and medical researchers and practitioners. Many aspects of this workshop were unusual and not previously expe rienced. Also, the hosting institution, the Max Planck Institute for Physics of Complex Systems (MPIPKS), at this time was brand new. The organiz ers' rather unconventional intention was to bring specialists of both groups together to really work together. Therefore, there was an excessive availabil ity of computers and the possibility to numerically study time series data sets practitioners had supplied from their own fields, e. g. electrocardiogram (ECG) data, electroencephalogram (EEG) data, data from the respiratory system, from human voice, human posture control, and several others. These data formed a much stronger link between theoreticians and applicants than any of the common ideas."

In this monograph, a statistical description of natural phenomena is used to develop an information processing system capable of modeling non-linear relationships between sensory data. The system, based on self-organized, optimal preservation of empirical information, applies these relationships for prediction and adaptive control.
This monograph is written for students, scientists and engineers in academia and industry who are interested in experimental work related to the adaptive modeling of natural laws, the development of sensory-neural networks, intelligent control, synergetics and informatics. No specific knowledge of advanced mathematics is presupposed. Examples taken from physics, engineering, medicine and economics demonstrate the applicability of such intelligent systems.

This volume contains the papers presented at the symposium on Biophysics and Physiology of Carbon Dioxide held at Regensburg, April 17-20, 1979. The manuscripts represent the full or even an extended account of the oral presentations. We have decided not to include any part of the discussions which took place after the lectures because this would have led to an undue enlargement of the already substantial volume. The symposium brought together some 60 scientists of various disciplines including biophysicists, chemists, biochemists, physiologists, pharmacologists, as well as clinicians whose research activities are cen tered around the various aspects of the reactions and the regulatory role of CO within the body. 2 In view of the fact that numerous textbooks and Proceedings of Symposia deal expertly with the role of CO in acid-base balance, it 2 was decided not to include this aspect in the present symposium. This holds also for the biochemistry of carboxylation and decarboxylation reactions. Particular emphasis was placed on the following subjects: (1) Chemical reactions of CO in water and facilitated diffusion of CO2, 2 (2) CO adducts to proteins, in particular hemoglobin, and peptide 2 hormones, (3) structure and function of carbonic anhydrase, (4) CO 2 exchange and carbonic anhydrase activity in respiratory and nonrespi ratory systems. Each section contains at least one introductory paper that presents the current knowledge in a more general framework."

Pulmonary Biology in Health and Disease was conceived as a companion to a handful of expensive, multivolume textbooks. This is part of the promising trend to publish shorter textbooks on the subjects of lung biology and remodeling. Whoever is familiar with human biology and the far-reaching consequences of the genome and postgenome revolutions is apt to concede that the centerpiece in remodeling lies in the ?eld of m- ecular cardiobiology. The ?eld of molecular cardiobiology includes the syndrome of chronic heart failure as well as ischemic cardioprotection. By analogy, the centerpiece in pulmonobiology is chronic asthma. Key topics in the present volume include s- naling mechanisms regulating the endothelium and smooth muscle cells,in?ammatory cells, mediators, airway surface liquid, and pharmacological therapy that focuses on how in?amed airways are altered. Written primarily for predoctoral and postdoctoral graduates in the basic medical sciences, the medical student and postdoctoral physician, graduates in the allied s- ences, nurses, pulmonologists, and physicians in critical care medicine, this book p- vides many of the fundamentals of contemporary pulmonology. It is divided into several parts devoted to the control of respiration, arterial chemoreceptors,muscles of ventilation, pulmonary physiology, and gas exchange in health, exercise, and disease. Special emphasis is placed on emphysema and its pathobiology, acute lung injury, asthma and inhaled toxicants. Because the ?eld is always evolving, each chapter includes recommended readings that lead the reader to sources of additional information, such as the review on remodeling of the blood gas barrier by West and Mathieu-Costello.

Physiologists have long been interested in the interaction, or coupling, between the heart and the vasculature. The early literature consists mainly of phenomenological descriptions of cardiac alterations resulting from specific interventions in the vasculature. Hundreds of studies, for example, describe functional aspects of hypertrophied myocardium associated with the excessive vascular loading produced by various types of experimental hypertension. Recently, the concepts of ventricular/vascular interaction have found important clinical application. The widespread use of vaso dilators and of intraaortic counterpUlsation balloons for unloading an ov erburdened, diseased heart is a prime example. Despite the interest in this field, until as recently as 20 years ago we were not able to describe ventricular or vascular function in a framework suitable for quantitatively expressing the interaction between these two complex systems. Three major developments-description of ventricular function in terms of both the time-varying elastance and the pump function graph and quantification of vascular function in terms of impedance have changed this. These functional descriptions now enable systems en gineers, bioengineers, physiologists, and clinicians to address very specific quantitative aspects of ventricular/vascular interaction and have resulted in a flurry of papers and symposia devoted to this subject."

The fourth Oxford Conference entitled "Control of Breathing: A Model ing Perspective" was held in September of 1988 at Grand Lake, Colorado. Grand Lake, also called Spirit Lake, was chosen for the fourth meet i ng so as to continue the meditative atmosphere of the previ ous meetings and to put the conference on a new higher plane (8,500 feet). The weather, as promised, exhibited its random-like rain showers. The snow report became essential for traveling the 12,000 foot passes to and from Grand Lake. Even the servi ces such as telephone and elect ri city proved to be uncertain. In all, the overall atmosphere of Spirit Lake contributed to an uninhibited free-style of presentation and interaction. All of us who attend the Oxford Conferences share a common interest in exploring respiratory control and the regulation of breathing. Modeling has become an adjunct to our exploration process. For us, models are tools that extend our ability to conceptualize just as instruments are tools that extend our ability to measure. And so these meetings attract physicians, physiologists, mathematicians and engineers who are modelers and modelers who are engineers, mathematicians, physiologists and physicians. Four of these physician-modelers have now passed away. They have been very important mentors for many of us. J. W. Bellville was my Ph.D. dissertation advisor at Stanford who introduced me to the intrigue of respiratory control. G. F. Filley was my colleague at the University of Colorado who enhanced my thinking about respiratory control. E. S.

Biologic System Evaluation with Ultrasound is a reference book for engineers in the field of ultrasonics and is intended to inform those unfamiliar with current methods of ultrasonic analysis. Explaining the mathematical and physical principles of ultrasound imaging of living tissue with effective precision, the book encompasses the following topics: relationships between the biological and scattering hierarchies; graphic description of scattering; class 1,2,3,4 scattering and their association with the biological hierarchy; instruments used for biologic system evaluation; computed tomographic methods of imaging. The authors have provided an effective explanation of the ultrasound scattering of image and image acquisition that will benefit engineers, physicists, and radiologists alike.

Insects as a group occupy a middle ground in the biosphere between bacteria and viruses at one extreme, amphibians and mammals at the other. The size and general nature of insects present special problems to the student of entomology. For example, many commercially available instruments are geared to measure in grams, while the forces commonly encountered in stUdying insects are in the milligram range. Therefore, techniques developed in the study of insects or in those fields concerned with the control of insect pests are often unique. Methods for measuring things are common to all sciences. Advances sometimes depend more on how something was done than on what was measured; indeed a given field often progresses from one technique to another as new methods are discovered, developed, and modified. Just as often, some of these techniques find their way into the classroom when the problems involved have been sufficiently ironed out to permit students to master the manipulations in a few laboratory periods. Many specialized techniques are confined to one specific research laboratory. Although methods may be considered commonplace where they are used, in another context even the simplest procedures may save considerable time. It is the purpose of this series (1) to report new developments in methodology, (2) to reveal sources of groups who have dealt with and solved particular entomological problems, and (3) to describe experiments which may be applicable for use in biology laboratory courses.

"Chemical physics is a science of the physical foundations of chemical transformations" (N. N. Semenov). The main objective of chemical physics is to disclose the detailed mechanism of chemical reactions and to learn to control these processes. The physico-chemical approach hinges upon the extensive application of methods of molecular physics and chemical kinetics. Based originally on simple gas-phase processes, chemical physics gradually extended its sphere of interest to liquid-phase reactions and to processes taking place in solids, including polymers. At present, we witness the fact that the ideas and methods of this science penetrate deeper and deeper into modern molecular biology, including enzyme catalysis. This monograph treats, from the standpoint of modern chemical physics, the principal general and individual features of the structure and mechanism of action of various classes of oxidation-reduction (redox) metalloenzymes. There are several reasons for which this branch of science attracts the attention of specialists in various fields - from biologists and those working in medicine to chemists and theoretical physicists. First of all, is the enormous biological and biochemical importance of processes catalyzed by metalloenzymes. These include biological ox idation with oxygen, oxidative and photo-phosphorylation, atmospheric nitrogen fixation, assimilation of nitrates and sulphites, phototransport of electrons, hydrogen evolution and hydrogenation and photo-oxida tion of water, which is far from a complete list of such processes."

The workshop on "Antennas and Reaction Centers of Photosynthetic Bac teria" was held at Feldafing, Bavaria (F. R. G. )' March 23-25, 1985. This workshop focussed on primary processes with emphasis on structure, inter actions and dynamics. It assessed structural, spectroscopic and dynamic data which have accumulated recently, providing an overview of the mech anism of the acquisition, storage and useful disposal of energy in bacterial photosynthesis. This volume is a record of the invited papers presented at the workshop. The material was organized into five sections: I. Antennas: Structure and Energy Transfer II. Reaction Centers: Structure and Interactions III. Electron Transfer: Theory and Model Systems IV. Reaction Cen,ters: Structure and Dynamics V. Model Systems on Function of Antennas and Reaction Centers I would like to express my gratitude to all the participants in the work shop for their contributions, and to the authors for the timely preparation of their manuscripts. I am indebted to the members of the organizing committee, Professors Sighart F. Fischer and Hugo Scheer for their most valuable assistance and advice. The workshop would not have been so successful without the help of my secretary, Frau Petra KahlfuB, and my coworkers in its organization. I thank Frau KahlfuB particularly also for her assistance in the preparation of these proceedings. The workshop was organized under the auspices of the Technical Uni versity of Munich, the Max-Planck-Society and the University of Munich.

The field of non-crystalline materials has seen the emergence of many challeng ing problems during its long history. In recent years, the interest in polymeric and biological disordered matter has stimulated new activities which in turn have enlarged the organic and inorganic glass community. The current research fields and recent progress have extended our knowledge of the rich phenomenol ogy of glassy systems, where the role of disorder is fundamental for the underlying microscopic dynamics. In addition, despite the lack of a unified theory, many interesting theoretical models have recently evolved. The present volume offers the reader a collection of topics representing the current state in the understanding of disorder effects as well as a survey of the basic problems and phenomena involved. The task of compiling a book devoted to disordered systems has benefited much from a seminar organized by the W.-E. Heraeus Foundation in Bad Honnef in April 1992, where we had the opportunity to discuss the project with most of the authors. Here we wish to thank the Heraeus Foundation for their support, and the authors and Springer-Verlag, especially Dr. Marion Hertel, for the pleasant cooperation."

Presented with a choice of evils, most would prefer to be blinded rather than to be unable to move, immobilized in the late stages of Parkinson's disease. Yet in everyday life, as in Neuroscience, vision holds the centre of the stage. The conscious psyche watches a private TV show all day long, while the motor system is left to get on with it "out of sight and out of mind. " Motor skills are worshipped at all levels of society, whether in golf, tennis, soccer, athletics or in musical performance; meanwhile the subconscious machinery is ignored. But scientifically there is steady advance on a wide front, as we are reminded here, from the reversal of the reflexes of the stick insects to the site of motor learning in the human cerebral cortex. As in the rest of Physiology, evolution has preserved that which has already worked well; thus general principles can often be best discerned in lower animals. No one scientist can be personally involved at all levels of analysis, but especially for the motor system a narrow view is doomed from the outset. Interaction is all; the spinal cord has surrendered its autonomy to the brain, but the brain can only control the limbs by talking to the spinal cord in a language that it can understand, determined by its pre-existing circuitry; and both receive a continuous stream of feedback from the periphery.

The past two decades have witnessed an unprecedented growth in the field ofneuroendocrinology. The conjoint research contributions by clinicians and basic scientists have promulgated revolutionary concepts at a breakneck speed. This first volume in Clinical Surveys in Endocrinology, The Pituitary Gland, has been written with but one purpose in mind: to integrate the current knowledge in this dynamic field with the existing body of information already available to the clinician. The chapters in this book attempt to portray current research information seen through the eyes of a clinician. The contributions of pioneers in each field have been placed in a perspective relevant to the practicing endocrinologist. The selection of the almost 1500 references from a bewil of literature has been inftuenced by the degree to which these dering body articles-original as weil as review papers-contributed to the growth of pi tuitary endocrinology. Despite the most scrutinizing attempts, it is inevitable and regrettable that works of importance must be excluded due to the practical limitations of any comprehensive work. Nevertheless, to the researcher these references are complete enough to serve as a significant resource. To the reader who wishes to gain an indepth clinical perspective of pituitary disor ders, this work is written precisely from that vantage point. The single authorship of this work notwithstanding, several friends have been instrumental in the completion of this work. I deeply appreciate the incessant zeal and excellent assistance of Ms."

Despite the fact that many years have elapsed since the first microcalorimetric measurements of an action potential were made, there is still among the research workers involved in the study of bioelectrogenesis a complete overlooking of the most fundamental principle governing any biological phenomenon at the molecular scale of dimension. This is surprising, the more so that the techniques of molecular biology are applied to characterize the proteins forming the ionic conducting sites in living membranes. For reasons that are still obscure to us the molecular aspects of bioelectrogenesis are completely out of the scope of the dynamic aspects of biochemistry. Even if it is sometimes recognized that an action potential is a free energy-consuming, entropy-producing process, the next question that should reasonably arise is never taken into consideration. There is indeed a complete evasion of the problem of biochemical energy coupling thus reducing the bioelectrogenesis to only physical interactions of membrane proteins with the electric field: the inbuilt postulate is that no molecular transformations, in the chemical sense, could be involved.

This Advanced Study Institute was arranged to discuss in depth the physical and technical basis of the latest developments in methods of measurement and image analysis suitable for determining the prop erties of cells and tissues and for evaluating medical structures. All topics under consideration have benefitted dramatically from an injection of new ideas during the past 10 years, and some have developed even more recently. The Institute brought together lecturers and participants from 14 different countries, and the subject matter recorded in this volume may be considered under two general headings. The first part of the meeting concentrated on techniques that are most appropriate at the cellular level. One major area of develop ment has been centered on attempts to classify cells by computerized ex traction of visual features, and here, it was notable how different techniques frequently complement each other. This part of the meeting also examined mechanisms of damage at the cellular level caused by different forms of radiation, and the contrasting effects of ionizing radiation, ultraviolet light and ultrasound were highlighted.