Epithelial cells probably constitute the most diverse group of cells found in the body. In addition to serving as interfaces between external and internal environments, their functions include ion and fluid secretion and reabsorp tion, protein exocytosis, hormone secretion, recognition, surface protection and the control of ciliary movement. By their very exposure on the surfaces of the body, epithelial cells are subjected to wide-ranging assault, by micro organisms and by chemical and physical forces. They are the targets for abrasion, infection and malignant transformation. Some epithelial cells show altered behaviour in inherited syndromes, such as cystic fibrosis, characterized by serious pancreatic and pulmonary disease. In view of the importance of epithelia and the fact that their function can be altered by environmental and inherited factors, they are the subject of intensive research, particularly so in the case of cancer where most tumours are of epithelial origin. The use of animal tissues in epithelial research continues to provide important advances and this, coupled with the need to focus more on human tissues, has prompted a greater research emphasis on accessible human epithelia and on the establishment of cell cultures from animal and human sources. For primary cell cultures and cell lines to be of value, they need to express properties appropriate to their progenitors and relevant to the study in progress."

This book is the lasting product, a resource of up-to-date information in the scientific literature for the field of animal cell technology, as it was presented during a pleasant and stimulating meeting in Tylosand, Sweden, in June 2001. The title of the meeting, From Target to Market, indicates the usefulness of Animal Cell Technology during all steps in the pharmaceutical development process. Following the biotech products reaching the market, it shows an upward trend in the contribution of biotech products to total New Molecular Entity output in the nineties, which continued until 1996 when biotech represented 25% of the annual output. Since then the proportion has been decreasing. A perceived hurdle from a market perspective is that a protein per definition is biodegradable and thus requires intravenous, or for some drugs subcutaneous administration. New promising administration technologies such as pulmonary delivery were highlighted at this meeting. The emphasis on project selection prior to entry in the development phase has triggered a portfolio management using more extensive preclinical data before a development decision is taken. Animal cells have become a very important tool in the drug discovery process. The next generation of products will evolve from applications such as gene therapy, novel vaccines, cell therapy, and gene regulation. Animal cell technology has a major role to play in the post-sequence era."

The ability of neoplastic cells to survive exposure to various chemotherapeutic drugs represents the main obstacle to successful cancer chemotherapy. This book deals with a particular type of resistance in tumor cells that represents a single but especially important aspect of the multifaceted problem of cancer drug resistance. This type of resistance, known as multidrug or pleiotropic drug resistance, is characterized by cross-resistance of cells to several different classes of cytotoxic drugs, including some of the most commonly used anticancer agents. Over the last several years, there has been a veritable explosion of genetic, biochemical, and clinical information on multidrug resistance, which followed the identification and cloning of the genes responsible for this phenotype and the isolation of monoclonal antibodies against P-glycoproteins, the products of these genes. Elucida tion of the molecular mechanism of multidrug resistance has led to the formulation of novel approaches to the prediction of tumor response to chemotherapeutic drugs and increasing the efficacy of cancer therapy. Analysis of the structure and function of P glycoproteins from multidrug-resistant mammalian cells has also established a prototype for a novel class of eukaryotic membrane proteins, which have now been associated with a variety of transport processes in different organisms. This book summarizes the results of molecular biological, pharmacological, bio chemical, cytogenetic, immunological, and pathological studies on multidrug resistance in mammalian cells. Most of the chapters deal at least to some extent with the structure and expression of P-glycoprotein and its role in multidrug resistance."

Research in animals and plants is frequently 'departmentalized' and funded according to Kingdoms by granting bodies. The use of transgenes to address biological questions in all Kingdoms led us to propose to the Royal Society that fundamental and strategic studies in animals and plants involving trans genes should be presented in one meeting, rather than, as so often happens, in different scientific societies. The two-day Discussion Meeting held inJuly 1992, and reported here provided insights into how trans genes are being exploited to discover new knowledge in animals and plants. The papers were presented by leading investigators in the biological sciences, and the book reflects an experiment in interdisciplinarity which was declared a successful venture by the large crowd of participants and delegates. The transgenic area is one of high scientific interest and sporadic, yet intense biotechnological euphoria. This is dramatically illustrated among the following papers which show how genetic maps of animals and plants produce new knowledge of disease incidence in humans, and how the design of transgenes can result in biodegradable plastic in higher plants, human pharmaceutical proteins in livestock, or bacterial proteins in cotton crops to protect against insect damage.

Currently one of the hottest topics in biochemistry, the concept of molecular chaperones has challenged the paradigm of protein self-assembly. Key figures in many disciplines review all aspects of molecular chaperones in this volume, which arises from a Royal Society discussion meeting. Overview chapters discuss the significance of chaperones in biochemistry, molecular genetics and cell biology. Each chapter is well referenced providing access to the literature.

This special volume is dedicated to the contributions of women ichthyologists. Three colleagues were selected to represent all women ichthyologists, Ethelwynn Trewavas (ET), Rosemary Lowe-McConnell (Ro) and Eugenie Clark (Genie). All have had distinguished professional careers and have contributed in their own ways to their science. The career of each is highlighted by a personal interview with one of the editors of the volume, a bibliography of their lifetime publications, and a biography of their careers. Questions of historical inequities and current controversies in the treatment of women ichthyologists by their peers are raised and addressed by the women themselves. The personal and professional influences of these three women, and other women ichthyologists, are highlighted. A survey article by Pat Brown brings a number of women ichthyologists to the attention of a broader audience, and points the way for a more comprehensive historical consideration of the accomplishments and contributions of women ichthyologists. The volume continues with 16 solicited and contributed papers. ET's studies of taxonomy and life history are echoed in papers on the taxonomy and systematics of marine angelfishes, and of freshwater bitterlings, a review of reproduction in the North Atlantic ichthyofauna, and a comparison of reproductive styles and systematics of African minnows. Ro's studies on ecology, life history and behaviour are paralleled by papers on growth and metabolism in piranha, the community structure in tide pool fishes, and the social system and reproductive patterns in groupers. Genie's pioneering work on sexual roles and sex change, and her field studies of the behaviour of marine fishes are reflected in papers on gonadal structure and environmental sex determination in brook lamprey, sexual patterns in hawkfish, reproduction and systematics in phallostethids, gonadal structure and systematics in gobiids, reproductive and predator avoidance behaviour in razorfish, early ontogeny of an African mouth brooder, and alternative life histories in killifish.

These Proceedings contain the contributions of the participants of the Second International Symposium on Dendritic Cells that was held from the 1st to 25th of June 1992 in Amsterdam, the Netherlands. The First International Symposium on Dendritic Cells was organized as a Satellite symposium at the occasion of the 30th anniversary of the Japanese Reticuloendothelial Society by Dr. Y. Imai in Yamagata (Japan), in 1990. It was entitled "Dendritic Cells in Lymphoid Tissues," and focused primarily on the Interdigitating Cells (IDC), Epidermal Langerhans cells (LC) and Follicular Dendritic Cells (FDC) , from the point of view of human pathology. However, the concept of Dendritic Cell System, comprising the bone marrow derived IDC and LC but not the FDC, was based on animal experiments and mainly on in vitro experiments on isolated cells. In a report from the Reticuloendothelial Society Committee on Nomenclature in 1982, Tew, Thorbecke and Steinman had already characterized these different types of DC, but the gap between in vivo and in vitro function remained. In Amsterdam, the Symposium focused on the Role of Dendritic Cells in Fundamental and Clinical Immunology. First, recent developments in molecular biology of antigen presentation and cell biological aspects of signal transduction were discussed, in relation to the potential of DC to stimulate lymphocytes and to trigger their in vitro differentiation.

During the past fifty years, thousands of natural products have been isolated from plants, fungi, and bacteria. Apart from intense searches by pharmaceutical companies for medicinals and the concentrated effort mounted by the National Cancer Institute, many of these have not been tested in biological systems. The major reasons for this appear to be, at least, twofold. First, individual researchers looking for biologically active natural products will often isolate only small amounts of material sufficient to determine a structure and calculate the specific activity for their particular bioassay systems: insufficient funds preclude re-isolating the compound unless industrial potential is foreseen. Second, the difficulty with which original structures were proved prior to 1972. This required the isolation of relatively large quantities of a natural product and there followed extensive degradation, elemental analyses of the parent and its fragments, then synthesis, piece by piece, of the molecule. All this took time and energy. No wonder that when the structure was proved the chemist was enervated. And coupled to this was the fact that many chemists were not trained to test their materials in biological systems. In contrast, today a natural product can be isolated, its mass and molecular formula determined and, if there is some serendipity, crystals may be obtained for single crystal x-ray analysis. If conditions are near perfect, it is possible to isolate and identify a novel compound in a month.

Microbes are known to live in an enormous range of environments. Their ability to survive and proliferate in diverse industrial systems is often a surprise to those not exposed to these problems in their work. These systems contain a range of potential carbon sources, one common theme being surfactants. Surfactants are often not the components most prone to spoilage since some systems contain highly susceptible natural components, such as starch and xanthum gum, but the surfactant is a key part of the formulation, and its extensive breakdown usually means that the material is beyond recovery. The aim of this book is to describe in detail all aspects of the preservation of surfactant containing materials. The book should be viewed as being in three discrete sections. * chapters 1-5 deal with and summarise essential background information * chapters 6-11 discuss in detail various end use applications * chapters 12-15 outline the regulatory and toxicology implication associated with the safe handling of preservatives Given the format of the book there is inevitably some duplication of information in the middle section with different authors describing essentially the same phenomena but on different substrates. I hope the reader will find that although different chapters touch on the same topics the information around these areas is sufficiently different to justify their inclusion in this book and to be of interest. It should also demonstrate what can be the most useful source of information, the hard practical experience of the authors.

It is now more than half a century since animal cells first came into regular use in the laboratory. Instances of laboratory acquired infection and con tamination of therapeutic products, derived from the use of animal cell cultures are rare. The use of animal cells, in addition to an established role in the production of vaccines and therapeutic proteins, has many new medical applications including gene therapy, tissue engineering and cell therapy. Furthermore, C;ldvances in molecular and cell biology are enabling rapid development and application of these technologies and the development of new and more sensitive methods, such as nucleic acid amplification, for the characterisation of cells and the detection of adven titious agents. However, it is clear that there is no room for complacency in this field and the recent expansion in the use of animal cells in the manufacture of medical products and the development of new biological assays for diagnostic and pharmaco-toxicological screening, underlines the need for vigilance regarding the correct and safe use of animal cells as substrates. This book is therefore very timely and should prove to be a highly valuable text, finding a wider audience beyond those with respon sibility for laboratory safety. The book guides the reader from fundamental cell biology issues and the establishment of new in vitro methods, through testing and validation of cell lines and on to issues in the use of animal cells in manufacturing processes."

The Jenner International Glycoimmunology Meetings have charted the rapid devel opment of glycobiology within the field of inflammation. In less than a decade, the science has grown from basically being involved in carbohydrate analysis to the understanding of how sugars are associated with inflammation and how they have potential as anti inflammatory therapeutics. The 4th Jenner International Glycoimmunology Meeting was re cently held in Loutraki, Greece, and set the scene for what promises to be an exciting future for the speciality. Discussion reflected the rapid advances glycobiology is making and ranged from the basic biochemistry of carbohydrate physiology to therapeutic trials utilizing synthetic sugars designed to block inflammatory responses. The meeting is summarized in considerable detail in this book which will provide the interested scientist and clinician with the essential up-to-date facts within the field of glyco immunology. Acknowledgments Many people have been involved in ensuring the success of the Jenner Glycoimmu nology Meetings but none more so than my secretary Susan Henderson who has borne the brunt of all four meetings and is currently preparing for the 5th.

The mycoplasmas, a trivial name used to denote organisms included in the class Mollicutes, are a group of prokaryotic organisms comprising more than 120 species distinguished from ordinary bacteria by their small size and the total lack of cell walls. The absence of a cell wall in mycoplasmas is a characteristic of outstanding importance to which the mycoplasmas owe many of their pecu liarities, for example, their morphological instability, osmotic sensitivity, unique ion pumping systems, resistance to antibiotics that interfere with cell wall bio synthesis, and susceptibility to lysis by detergents and alcohols. The fact that the mycoplasma cells contain only one membrane type, the plasma membrane, constitutes one of their most useful properties for membrane studies; once the membrane is isolated, it is uncontaminated with other mem brane types. Another advantage in using mycoplasmas as models for membrane studies stems from the fact that their membrane lipid composition can be altered in a controlled manner. This characteristic results from the partial or total inabili ty of the mycoplasmas to synthesize long-chain fatty acids and cholesterol, making mycoplasmas dependent on the supply of fatty acids from the growth medium. The ability to introduce controlled alterations in the fatty acid composi tion and cholesterol content of mycoplasma membranes has been utilized in studying the molecular organization and physical properties of biological mem branes.

Following pioneering work by Harrison on amphibian limbs in the 1920s and by Saunders (1948) on the apical ridge in chick limbs, limb development became a classical model system for investigating such fundamental developmental issues as tissue interactions and induction, and the control of pattern formation. Earlier international conferences, at Grenoble 1972, Glasgow 1976,and Storrs, Connecticut 1982, reflected the interests and technology of their time. Grenoble was concerned with ectoderm-mesenchyme interaction, but by the time of the Glasgow meeting, the zone of polarizing activity (ZPA) and its role in control of patterning was the dominant theme. Storrs produced the first intimations that the ZPA could be mimicked by retinoic acid (RA), but the diversity of extracellular masrix ~olecules,particularly in skeletogenesis,was the main focus of attention. By 1990, the paradigms had again shifted. Originally, the planners of the ARW saw retinoic acid (as a possible morphogen controlling skeletal patterning), the variety of extracellular matrix components and their roles, and the developmental basis of limb evolution as the leading contemporary topics. However, as planning proceeded, it was clear that the new results emerging from the use of homeobox gene probes (first developed to investigate the genetic control of patterning of Drosophila embryos) to analyse the localised expression of "patterning genes" in limb buds would also be an important theme.

RAN: AN ATYPICAL GTPASE Mark G. Rush and Peter D'Eustachio New York University School o/Medicine. Department,o/Biochemistry New York NY 10016 ABSTRACT GTPases, proteins that bind and hydrolyze GTP (guanosine triphos- phate) are critical regulators of many metabolic pathways. Although these proteins are enzymes that catalyze the hydrolysis of GTP to GDP + Pi, their primary function is not the hydrolysis of GTP per se, but rather the coupling of this hydrolysis to metabolic regulation. Such coupling is gen- erally achieved through the interaction of the GTP-bound form of the GTPase with proteins known as *effectors. Effectors are often enzymes whose activities are modulated by the GTPase. However, effectors can also be structural proteins involved in assembling intracellular macromo- lecular complexes, such as actin filaments and microtubules, as well as proteins involved in the intracellular transport of proteins and RNAs. In- deed, the subject of this anthology, the small GTPase Ran, may exert most or all of its regulatory functions by interacting with non-enzyme effectors. This property of Ran distinguishes it from other well studied GTPases, and has resulted in the elucidation of novel mechanisms of Ran action that are quite distinct from previously established paradigms of GTPase function. 1. INTRODUCTION The Ras-related nuclear protein Ran is a highly conserved (80% identity among yeasts and humans) member of the Ras superfamily of small GTP binding and hydrolyzing proteins.

Since the limnological research on the man-made Brokopondo Reservoir in the 'sixties, numerous data have been collected on the ecology of Surinam rivers and swamps. This book is a compilation of these data: it is the first comprehensive survey of the aquatic ecology of one of the peripheral areas of Amazonia. The geomorphology of the country, situated on the Guyana Shield, is the main factor determining the limnological properties of rivers and creeks. This results in an overall picture that is quite different from Amazonia. The emphasis of The Ecosystems of Suriname is on the living aquatic resources, including aquatic and swamp vegetation, phyto and zooplankton, macroinvertebrates, fish, amphibians, reptiles and mammals. Although most of Suriname is still in a pristine state, the human impact on fresh waters is considerable in those areas of rapid economic development, emphasizing the necessity of conservation measures, specially tailored for aquatic ecosystems. The Ecosystems of Suriname is a valuable acquisition for all scientists, environmental managers and others interested in tropical aquatic ecology.

The tenth Henry Goldberg Workshop is an excellent occasion to recall our goals and celebrate some of our humble achievements. Vision and love of our fellow man are combined here to: 1) Foster interdisciplinary interaction between leading world scientists and clinical cardiologists so as to identify missing knowledge and catalyze new research ideas; 2) relate basic microscale, molecular and subcellular phenomena to the global clinically manifested cardiac performance; 3) apply conceptual modelling and quantitative analysis to better explore, describe, and understand cardiac physiology; 4) interpret available clinical data and design new revealing experiments; and 5) enhance international cooperation in the endless search for the secrets of life and their implication on cardiac pathophysiology. The first Goldberg Workshop, held in Haifa, in 1984, explored the interaction of mechanics, electrical activation, perfusion and metabolism, emphasizing imaging in the clinical environment. The second Workshop, in 1985, discussed the same parameters with a slant towards the control aspects. The third Goldberg Workshop, held in the USA at Rutgers University, in 1986, highlighted the transformation of the microscale activation phenomena to macro scale activity and performance, relating electrophysiology, energy metabolism and cardiac mechanics. The fourth Goldberg Workshop continued the effort to elucidate the various parameters affecting cardiac performance, with emphasis on the ischemic heart. The fifth Workshop concentrated on the effect of the inhomogeneity of the cardiac muscle on its performance. The sixth Workshop highlighted new imaging techniques which allow insight into the local and global cardiac performance.

Leishmania parasites cause a diverse group of diseases endemic to many tropical and subtropical regions of the world. This volume seeks to bring together recent research on cell and molecular biology of Leishmania with chapters on the host response to infection, the current epidemiology of leishmaniasis, explanations of the many different species, vector control, and strategies for vaccine development and drug treatment. Leishmania, volume four of World Class Parasites, is written for researchers, students and scholars who enjoy reading research that has a major impact on human health, or agricultural productivity, and against which we have no satisfactory defense. It is intended to supplement more formal texts that cover taxonomy, life cycles, morphology, vector distribution, symptoms and treatment. It integrates vector, pathogen and host biology and celebrates the diversity of approach that comprises modern parasitological research.

Individual cells behave in surpnsmg ways that cannot be deduced from the averaged results of an organ as assessed by the use of conventional biochemical methods. Thus multicellular plant and animals systems are being investigated by an increasing array of histochemical and cytochemical techniques based on general chemical or specific immunological interactions to identify structural materials and to assess biological activities. In recent years there has been an increasing range of fluorescent probes, along with advanced computerised imaging and analysis techniques, which allows the behaviour of individual living cells to be followed in considerable detail. The parallel use of microinjection, microelectrodes and patch-clamping provides additional information about cells and their responses. Recombinant DNA technology has highlighted the desirability and the power of microinjecting defined materials into specific cells and so manipulating their fundamental biochemistry. New hypotheses are being tested which will form the cornerstone of future developments across the whole spectrum of biotechnology. The First European Workshop on Biotechnology Applications of Microinjection, Microscopic Imaging and Fluorescence was run at the University of East London, U.K, 21st-24th April, 1992 with the objective of bringing together a diverse group of individuals who were using these state-of-the-art applications for biotechnological exploration. A novel feature of the meeting was paiticipation by instrument manufacturers in the programme: there were hands-on workshops (where living cells could be examined), combined with the poster sessions.

The therapeutic efficacy of FUra has been attributed to its incorporation into cellular RNA and, to its inhibition of thymidylate synthase, leading to potent inhibition of DNA synthesis and DNA damage. Studies of cell lines in vitro and model systems in vivo have demonstrated that although mechanisms of sensitivity and resistance to FUra are multifactorial, in the presence of citrovorum factor (LV, CF, 5-formyltetrahydrofolate) the site of action of FUr a becomes predominantly the pronounced and prolonged inhibition of thymidylate synthase. This action is the result of stabilization of the covalent ternary complex between FdUMP, an active metabolite of FUr a, 5, IO-methylenetetrahydrofolates, and thymidylate synthase. This effect of LV is thus an example of the concept of metabolic modulation. CF is commercially available as a racemic mixture of diastereoisomers (6R and 6S). The 6R isomer is considered to be biologically inactive; the 6S isomer is the biologically active form that is metabolized intracellularly to' form the various folate cofactor pools including 5, IO-methylenetetrahydrofolates. Although the extent of metabolism of folates in normal and tumor tissues has not been clearly delineated, it has been determined that the formation of folypolyglutamates is primarily a function of schedule of CF administration, while the retention of significant concentrations of reduced folate is a function of the dose and also the schedule of LV. Thus, it appears that for optimal modulation of FUra activity several factors must be considered simultaneously.

Animal cell technology is a growing discipline of cell biology which aims to understand the structure, function and behaviour of differentiated animal cells, and especially the development of such abilities as are useful for industrial purposes. These developments range from clonal expansion of differentiated cells with useful abilities, to optimization of cell culture on industrial scale and modulation of the cells' abilities to produce drugs and monoclonal antibodies. The sixth volume in this series gives a complete review of today's state of the art in Japan, a country where this field is especially well advanced. It will be of interest to cell biologists, biochemists, molecular biologists, immunologists and other disciplines related to animal cell culture, working in the academic environment as well as in (biotechnology or pharmaceutical) industry.

Fungal dimorphism is a topic that sounds inherently too rarified to attract more than a specialist audience. Yet some 230 individuals representing an eclectic mixture of interests, from basic science to medical practice, gathered in Churchill College, Cambridge in Semptember 1992 for a meeting devoted only to this subject. The symposium was the fourth in a series "Topics in Mycology" to be jointly organized by the Janssen Research Foundation and the International Society for Human and Animal Mycology. The participants enjoyed a rich and varied diet of oral presentations and poster displays in the field of fungal morphogenesis. This book sets down in print the material presented at the dimorphism symposium. We think that the high quality of these papers conveys very well the flavor of what was an excellent meeting. The selection of contributions in this volume covers very wide ground indeed. Chapters devoted to some non-pathogenic fungi are included, because the scientific basis of morphological development belongs to the fields of cellular and molecular biology: it does not recognize the boundary imposed by considerations of virulence of a fungus for a human host. Yet morphogenetic change in those fungi that do cause human disease frequently appears to be a component of the pathological process: many important pathogens change from a hyphal form in the external environment to a round form in infected tissues. This relationship between dimorphism and pathogenicity is the point of contact between pure biology and medicine.

As discussed in this book, a large body of evidence indicates that selenium is a cancer chemopreventive agent. Further evidence points to a role of this element in reducing viral expression, in preventing heart disease, and other cardiovascular and muscle disorders, and in delaying the progression of AIDS in HIV infected patients. Selenium may also have a role in mammalian development, in male fertility, in immune function and in slowing the aging process. The mechanism by which selenium exerts its beneficial effects on health may be through selenium-containing proteins. Selenium is incorporated into protein as the amino acid selenocysteine. Selenocysteine utilizes a specific tRNA, a specific elongation factor, a specific set of signals, and the codeword, UGA, for its cotranslational insertion into protein. It is indeed the 21st naturally occurring amino acid to be incorporated into protein and marks the first and only expansion of the genetic code since the code was deciphered in the mid 1960s.

North American Parasitic Zoonoses provides a concise and useful review of essential information about parasitic zoonotic diseases. North American Parasitic Zoonoses, volume six of "World Class Parasites", is written for researchers, students, veterinarians, physicians and scholars who enjoy reading research that has a major impact on human health, or agricultural productivity, and against which we have no satisfactory defense. It is intended to supplement more formal texts that cover taxonomy, life cycles, morphology, vector distribution, symptoms and treatment. It integrates vector, pathogen and host biology and celebrates the diversity of approach that comprises modern parasitological research.

In this volume, a distinguished international group of contributors present the latest molecular, organismal, and epidemiological research on arenaviruses. Their work will broaden both the clinician's and the researcher's knowledge of basic mechanisms of immunological tolerance, viral immunosuppression, the nature of protective immune responses to vaccination, and viral effects on cell functions.

This volume contains the proceedings of the NATO ARW on 'Biological Pattern Formation' held at Merton College, University of Oxford, on 27-31 August, 1992. The objective of the workshop was to bring together a select group of theoreticians and experimental biologists to present the latest results in the area of biological pattern formation and to foster interactiqn across dis- plines. The workshop was divided into 5 main areas: (i) limb development, (ii) Dictyostelium discoideum, (iii) Drosophila, (iv) cell movement, (v) g- eral pattern formation. We thank all the participants for their contributions, enthusiasm, and willingness to collaborate. There was a genuine, open, and extremely fru- ful interaction between the experimentalists and theoreticians which made the workshop a success. We also thank The Welcome Trust for providing additional funding. The local organization fell mainly on Denise McKittrick and Beverley Bhaskhare at the Mathematical Institute, Oxford, and Jeanette Hudson and the staff of Merton College. We greatly appreciate their help and patience. We also thank Jonathan Sherratt, Wendy Brandts and Debbie Benson for helping out in the conference and for providing a happy welcome to parti- pants on a typically cold, wet and windy English summer day.