Elsevier bv okt 1996 (5 risultati)

Buch. Condizione: Neu. Neuware - This is the first in a series of volumes concerning the properties of the eukaryotic nucleus. Contributions from several of the most active laboratories are brought together to present a focused overview of a selected aspect of nuclear structure and function.

Buch. Condizione: Neu. Neuware - Volume 3 of Biomembranes covers receptors of cell adhesion and cellular recognition. Proteins in the plasma membrane of cells are heavily involved in processes of cell adhesion, but such proteins were not actually isolated and characterized until the mid-1970s. Since then, application of the methods of molecular biology has led to the recognition of four major classes of cell adhesion molecule (CAMs), the immunoglobulin super family, the cadherins, the integrins, and the selecting. A convenient system in which to study the importance of cell adhesion is in blood platelets where aggregation eventually leads to thrombus formation in a process involving a range of surface glycoproteins. Interaction with the extracellular matrix is exemplified by CD44, the receptor for hyaluronan, and a complex carbohydrate that is a major component of the extracellular matrix surrounding migrating and proliferating cells. Membrane-associated mucins have a variety of effects on cell adhesion. The super family of immunoglobulin related proteins also include the T cell receptors and the major histocompatibility complex (MHC), which, together with the receptors for immunoglobulins (the Fc receptors), are of fundamental importance in the processes of immunity. Volume 3 of Biomembranes explores the structures and functions of the molecules involved in these important functions of the cell.…

Taschenbuch. Condizione: Neu. Neuware - The book focuses on a conceptual flaw in contemporary artificial intelligence and cognitive science. Many people have discovered diverse manifestations and facets of this flaw, but the central conceptual impasse is at best only partially perceived. Its consequences, nevertheless, visit themselves asdistortions and failures of multiple research projects - and make impossible the ultimate aspirations of the fields.The impasse concerns a presupposition concerning the nature of representation - that all representation has the nature of encodings: encodingism. Encodings certainly exist, butencodingism is at root logically incoherent; any programmatic research predicted on it is doomed too distortion and ultimate failure.The impasse and its consequences - and steps away from that impasse - are explored in a large number of projects and approaches. These include SOAR, CYC, PDP, situated cognition, subsumption architecture robotics, and the frame problems - a general survey of the current research in AI and Cognitive Science emerges.Interactivism, an alternative model of representation, is proposed and examined.…

Buch. Condizione: Neu. Neuware - It is now clear from a wide range of research that cytoplasm is not merely a buffered solution of proteins and enzymes but contains a series of complex filamentous structures. The cytoskeleton is the collective term given to these filaments. There is a considerable amount of data available on the protein composition of the major filament systems (microfilaments, microtubules, and intermediate filaments) but we are still comparatively ignorant about the role of the cytoskeleton in cell physiology. However such major cytoplasmic components (actin and tubulin, the monomeric constituents of microfilaments and microtubules, are major cell proteins) must have important roles to play in cell function, and investigations into the functional role of the cytoskeleton currently represent a major area of cell biological research.In recent years rapid advances in molecular biology have begun to influence research on the cytoskeleton. This trend is sure to continue and the techniques of molecular biology and genetics are set to make major contributions to our understanding of the cytoskeleton, as illustrated in this volume by several reviews; the use of transfection techniques by Ben-Ze'ev, the power of Drosophila genetics is described by Fyrberg and the major advances made in the inesin field using molecular approaches as described by Cyr et al. The chapters by Fyrberg and Cyr et al. also illustrate two other areas where major advances in our understanding of the cytoskeleton is occuring; the great array of different motor proteins involved in intracellular movements and the study of the cytoskeleton in developmental biology. Overall, Volume 12 in this series illuminates our increasing knowledge of the important roles of the cytoskeleton in cell function, particularly how it is central to metabolic organization, intracellular transport, interactions with matrix, and nerve function. Our knowledge of the cytoskeleton is now reaching a stage where it is clear that abnormalities in the organization of the cytoskeleton can lead to important clinical manifestations of disease; an example of how such research is now impinging on medical science is presented in the final chapter by Lane on keratin diseases.…

Buch. Condizione: Neu. Neuware - Stimulus class formation has been studied independently by two groups of researchers. One group has come out of a learning theory approach, while the second has developed out of a behavior analytic tradition. The purpose of the present volume is to further establish the ties between these two research areas while allowing for differences in approach to the questions asked. The book is loosely organized around four themes. The first two sections deal with what constitutes functional and equivalence classes in animals and humans. In the third section, the authors attempt to identify stimulus control variables that contribute to the formation of equivalences classes. The last section deals with the complex issue of the role of verbal behavior in equivalence classes. The goal of the book is to provide the reader with a better understanding of the current state of research and theory in stimulus class formation. It is also hoped that it will stimulate research into how and under what conditions, stimulus classes can form.…