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Taschenbuch. Zustand: Neu. Neuware -Recent developments in various areas of chemistry have been decisively influenced by the principles of structure and mechanism and by the ideas of coordination chemistry, in particular by the donor-acceptor approach, A unified view of almost all kinds of molecular forces is provided by quantum mechanics, and for practical purposes have been classified according to model assumptions, namely, dispersion, polarization, electrostatic, and short-range forces. The latter are divided into two- and three-center covalent chemical bonds, metallic bonds, and exchange-repulsion forces. This approach allows statements of principle and systematic analysis. However, quantitative predictions on concrete large systems are virtually impossible, and there are no general rules that account for structural and chemical changes due to intermolecular interactions. Chemists are therefore left with qualitative descriptions in which the changes in electron densities are considered. Such models as the MO theory or the resonance concept unrealistically assume that the nuclei remain in fixed positions. Further difficulties are encountered in the attempted description on the 'nature' of the chemical bond, e.g., the forces involved. In order to avoid these difficulties an extension of the donor-acceptor concept, characterized by the comparison between equilibrium structures in different molecular environments, will be presented in this book. In this way, changes in the positions of the nuclei can be taken into account and the question of the nature of the molecular forces is no longer important.Springer Verlag GmbH, Tiergartenstr. 17, 69121 Heidelberg 296 pp. Englisch.

Taschenbuch. Zustand: Neu. Neuware - Recent developments in various areas of chemistry have been decisively influenced by the principles of structure and mechanism and by the ideas of coordination chemistry, in particular by the donor-acceptor approach, A unified view of almost all kinds of molecular forces is provided by quantum mechanics, and for practical purposes have been classified according to model assumptions, namely, dispersion, polarization, electrostatic, and short-range forces. The latter are divided into two- and three-center covalent chemical bonds, metallic bonds, and exchange-repulsion forces. This approach allows statements of principle and systematic analysis. However, quantitative predictions on concrete large systems are virtually impossible, and there are no general rules that account for structural and chemical changes due to intermolecular interactions. Chemists are therefore left with qualitative descriptions in which the changes in electron densities are considered. Such models as the MO theory or the resonance concept unrealistically assume that the nuclei remain in fixed positions. Further difficulties are encountered in the attempted description on the 'nature' of the chemical bond, e.g., the forces involved. In order to avoid these difficulties an extension of the donor-acceptor concept, characterized by the comparison between equilibrium structures in different molecular environments, will be presented in this book. In this way, changes in the positions of the nuclei can be taken into account and the question of the nature of the molecular forces is no longer important.

Taschenbuch. Zustand: Neu. Neuware - Information systems science is rapidly advancing in many directions. Di versified ideas, methodologies, and techniques as well as applications have been conceived and developed. This series intends to discuss some of the recent advances in this field. In this volume, we cover four timely topics which are of great current interest. In each chapter, an attempt is made to familiarize the reader with some basic background information on the ad vances discussed. The emphasis of this volume is placed upon parallel pro gramming, data structure models in information system design, and the principles of L systems. One of the effective means to enhance computation performance is parallel information processing on multiprocessor systems. In Chapter I, V. E. Kotov discusses the practical aspects of parallel programming. He is concerned with the languages and methods of parallel programming, per formance an~lysis, and automatic synthesis of parallel programs. In Chapter 2, A. S. Narin'yani presents the formal theory of parallel computations. These two chapters attempt to correlate and classify various methods in parallel programming, thus providing the reader with a unified approach to this important subject matter. Data structures play an important role in information system design.

Taschenbuch. Zustand: Neu. Neuware - The original premise of the Editors in initiating this series was that there existed a readership ofneurochemists with considerable biochemical back ground who would make use of a series dedicated to both new develop ments and specialized reviews in neurochemistry. Having selected our authors, we have offered them virtually complete freedom to reflect and speculate in a field in which they have achieved prominence. The response to the first two volumes has been rewarding. The present one continues in this tradition. While we have not attempted to publish specialized volumes, the present volume contains two somewhat related chapters (Chapters 4 and 5, on the role of amino acid neurotransmitters). The first three chapters examine three diverse approaches, each of current interest, in neurochemi cal approaches to the molecular bases of neuronal and glial structure. B. W. Agranoff M. H. Aprison vii CONTENTS CHAPTER 1 2',3'-CYCUC NUCLEOTIDE 3'-PHOSPHODIESTERASE NEIL RAYMOND SIMS AND PATRICK ROBERT CARNEGIE 1. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2. Assay of CNPase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. 1. Need for Activation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. 2. Comparison of Assays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Association of CNPase with Myelin . . . . . . . . . . . . . . . . . . . . . . . 7 3. 1. Historical. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3. 2. Subcellular Fractionation. . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3. 3. Development. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3. 4. Mutant Mice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3. 5. Use as a Myelin Marker . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 3. 6. Myelin-Related Fractions and Peripheral Nerve Myelin. 11 4. CNPase in Nonmyelin Fractions. . . . . . . . . . . . . . . . . . . . . . . . . . 13 5. Activation and Isolation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 5. 1. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 5. 2. Activation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 5. 3. Solubilization and Fractionation. . . . . . . . . . . . . . . . . . . . . . 15 6. Properties. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 6. 1. Substrate Specificity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Taschenbuch. Zustand: Neu. Neuware - This volume, the fifth of a continuing series on information systems science, covers four timely topics which are in the mainstream of this field. In each chapter, an attempt is made to familiarize the reader with basic background information on the advances discussed, so that this volume may be used independently or in conjunction with the previous volumes. The emphasis in this volume is focused upon data organization and access methods, software for on-line minicomputer applications, advances in micropro graming, and gramm ars and recognizers for formal and natural languages. In Chapter 1, P. C. Patton presents a tutorial survey of data organiza tion and access methods which play a central role in information system design. Research in information processing has been shifted from numerical data processing to nonnumerical information handling. In the latter case, the information is carried not only by the data but also by the structure and organization of the data base. In this chapter, the author provides the reader with a comprehensive review of various data structures, including linear lists, array structures, tree structures, and multilinked structures. He also discusses the important problem of data-base design and management. This chapter concludes with several examples of information handling systems such as a matrix interpretive system, a generalized information management system, and a criminal justice information system. The rapid reduction in cost and great increase in capability of the mini computer have made it an attractive machine for information systems.

Taschenbuch. Zustand: Neu. Neuware - Information systems science embraces a broad spectrum of topics. It is vir tually impossible to provide comprehensive and in-depth discussion, other than simple recitals of recent results, of every important topic in each volume of this annual review series. Since we have chosen the former approach, each volume will only cover certain aspects of recent advances in this bur geoning field. The emphasis in this volume, the third of a continuing series, is focussed upon pattern recognition, pictorial information manipulation, and new approaches to logical design of information networks. In Chapter 1, V. A. Kovalevsky presents a tutorial survey of practical and theoretical developments in pattern recognition. He categorizes the basic developments in three different directions. The first direction is charac terized by an empirical treatment with highly specialized recognition schemes. In the second direction, the major efforts are centered upon the cre ation of learning systems capable of improving recognition performance on the basis of past experience. The majority of the work in the third direction is devoted to the study of the basic structure of complex patterns, the con struction of mathematical models for pattern recognition, and the analysis of complex pictorial representations. The author elucidates the 'heuristics' approach and the 'science' approach to pattern recognition problems. This chapter together with Chapter 2 of this volume supplements the chapter on Engineering Principles of Pattern Recognition in Volume 1 to provide a more complete treatment of this subject.

Taschenbuch. Zustand: Neu. Neuware - It is only relatively recently that neurochemists and neurobiologists have shown appreciable interest in the class of macromolecules now generally re ferred to as complex carbohydrates, although gangliosides were, of course, first identified and studied in brain. The glycosaminoglycans fell chiefly within the province of connective-tissue biochemists, and earlier informa tion concerning the structure and metabolism of glycoproteins was largely limited to the more accessible glycoproteins and oligosaccharides (such as those found in plasma, milk, and urine), or ones which are relatively simple to prepare in a soluble and manageable form. Techniques were later devised for the isolation and purification of tightly bound membrane glycoproteins, where initial studies concentrated mainly on the erythrocyte, for which large amounts of a single cell population are available. Because of the structural complexity of nervous tissue and the large numbers, low concentrations, and membrane-bound form of many of its complex carbohydrates, progress has occurred more slowly in this area.

Taschenbuch. Zustand: Neu. Neuware - The time seems ripe for a critical compendium of that segment of the biological universe we call viruses. Virology, as a science, having passed only recently through its descriptive phase of naming and num bering, has probably reached that stage at which relatively few new truly new-viruses will be discovered. Triggered by the intellectual probes and techniques of molecular biology, genetics, biochemical cytology, and high resolution microscopy and spectroscopy, the field has experienced a genuine information explosion. Few serious attempts have been made to chronicle these events. This comprehensive series, which will comprise some 6000 pages in a total of about 18 volumes, represents a commitment by a large group of active investigators to analyze, digest, and expostulate on the great mass of data relating to viruses, much of which is now amorphous and disjointed, and scattered throughout a wide literature. In this way, we hope to place the entire field in perspective, and to develop an invalua ble reference and sourcebook for researchers and students at all levels. This series is designed as a continuum that can be entered anywhere, but which also provides a logical progression of developing facts and integrated concepts.

Taschenbuch. Zustand: Neu. Neuware - Prostaglandins, Leukotrienes, and Cancer is a multi-volume series that will focus on an emerging area of cancer research. In 1968, R.H. Williams first reported that elevated prostaglandin levels are present in human medullary car cinoma. Since that time, the concept that arachidonic acid metabolites may be in volved in cancer has expanded to include every aspect of the disease from cell transformation through metastasis. Prostaglandins and leukotrienes are generic terms used to describe a family of bioactive lipids produced from unsaturated fatty acids (principally from arachidonic acid) via the cyclooxygenase and lipoxygenase pathways, respec tively. Cyclooxygenase products consist of diverse products such as prosta glandin Ez (PGEz), prostacyclin (PGIz) and thromboxane Az (TXAz), whereas lipoxygenase products consist of hydroperoxy fatty acids and mono-, di- and tri-hydroxy acids including leukotrienes. The precursor fatty acids for the cyclooxygenase and lipoxygenase pathways are present in cellular phospholipids. This finding established an important control point in their biosynthesis-the release of substrate. This occurs in response to numerous stimuli that act at the cell surface. Dr. Bengt Samuelsson's extensive study of the metabolism of pros taglandins indicated that they are rapidly inactivated on a single pass through pulmonary circulation. Thus, they cannot act as circulating hormones and appear to be made on demand in or in the vicinity of target tissues leading to the concept that prostaglandins are local hormones or autocoids.

Taschenbuch. Zustand: Neu. Neuware - VHDL is a comprehensive language that allows a user to deal with design complexity. Design, and the data representing a design, are complex by the very nature of a modern digital system constructed from VLSI chips. VHDL is the first language to allow one to capture all the nuances of that complexity, and to effectively manage the data and the design process. As this book shows, VHDL is not by its nature a complex language. In 1980, the U. S. Government launched a very aggressive effort to advance the state-of-the-art in silicon technology. The objective was to significantly enhance operating performance and circuit density for Very Large Scale Integration (VLSI) silicon chips. The U. S. Government realized that in order for contractors to be able to work together to develop VLSI products, to document the resulting designs, to be able to reuse the designs in future products, and to efficiently upgrade existing designs, they needed a common communication medium for the design data. They wanted the design descriptions to be computer readable and executable. They also recognized that with the high densities envisioned for the U. S. Government's Very High Speed Integrated Circuit (VHSIC) chips and the large systems required in future procurements, a means of streamlining the design process and managing the large volumes of design data was required. Thus was born the concept of a standard hardware design and description language to solve all of these problems.

Taschenbuch. Zustand: Neu. Neuware - A: Biochemistry of Platinum Complexes in Cancer Chemotherapy.- B: Pharmacological Mechanisms and Toxicology of Platinum Complexes as Antitumor Agents.- C: Clinical Applications of Platinum Complexes.- D: Advances in Antitumor Research with Platinum and Non-Platinum Complexes; Development of New Metal Coordination Compounds: Synthesis and Characterization.- Author Index.