This book lays out a number of the general issues concerning the structure of rugged fitness landscapes and examines both the history and the current status of experimental work on somatic mutation and the maturation of the immune response.

Assuming that the complex phenomena underlying the operation of the immune system may be better understood through the collaborative efforts of theorists and experimentalists viewing the same phenomena in different ways, the Sante Fe Institute and the Theoretical Division of Los Alamos National Laboratory cosponsored a workshop entitled "Theoretical Immunology". The workshop focused on themes spanning the field of immunology, with emphasis on areas where the theorists have made the most progress. This book covers the discussions a that workshop on the topics of immune surveillance, mathematical models of HIV infection, complexities of antigen-antibody systems, immune suppression and tolerance, and idiotypie networks. In each of these areas there is reason to believe that advances can be made either through interactions among experimentalists and theorists or through the critical look experimentalists and theorists will bring to bear upon one another's work.

Assuming that the complex phenomena underlying the operation of the immune system may be better understood through the collaborative efforts of theorists and experimentalists viewing the same phenomena in different ways, the Sante Fe Institute and the Theoretical Division of Los Alamos National Laboratory cosponsored a workshop entitled "Theoretical Immunology." The workshop focused on themes spanning the field of immunology, with emphasis on areas where the theorists have made the most progress. This book covers the discussions a that workshop on the topics of immune surveillance, mathematical models of HIV infection, complexities of antigen-antibody systems, immune suppression and tolerance, and idiotypie networks. In each of these areas there is reason to believe that advances can be made either through interactions among experimentalists and theorists or through the critical look experimentalists and theorists will bring to bear upon one another's work.

Assuming that the complex phenomena underlying the operation of the immune system may be better understood through the collaborative efforts of theorists and experimentalists viewing the same phenomena in different ways, the "Sante Fe Institute" and the Theoretical Division of "Los Alamos National Laboratory" cosponsored a workshop entitled "Theoretical Immunology." The workshop focused on themes spanning the field of immunology, with emphasis on areas where the theorists have made the most progress. This book covers the discussions a that workshop on the topics of immune surveillance, mathematical models of HIV infection, complexities of antigen-antibody systems, immune suppression and tolerance, and idiotypie networks. In each of these areas there is reason to believe that advances can be made either through interactions among experimentalists and theorists or through the critical look experimentalists and theorists will bring to bear upon one another's work.

Assuming that the complex phenomena underlying the operation of the immune system may be better understood through the collaborative efforts of theorists and experimentalists viewing the same phenomena in different ways, the "Sante Fe Institute" and the Theoretical Division of "Los Alamos National Laboratory" cosponsored a workshop entitled"Theoretical Immunology." The workshop focused on themes spanning the field of immunology, with emphasis on areas where the theorists have made the most progress. This book covers the discussions a that workshop on the topics of immune surveillance, mathematical models of HIV infection, complexities of antigen-antibody systems, immune suppression and tolerance, and idiotypie networks. In each of these areas there is reason to believe that advances can be made either through interactions among experimentalists and theorists or through the critical look experimentalists and theorists will bring to bear upon one another's work.

Immunology is largely a science of observation and experimentation, and these approaches have lead to great increases in our knowledge of the genes, molecules and cells of the immune system. This book is an up-to-date discussion of the current state of modelling and theoretical work in immunology, of the impact of theory on experiment, and of future directions for theoretical research. Among the topics discussed are the function and evolution of the immune system, computer modelling of the humoral immune response and of idiotypic networks and idiotypic mimicry, T-cell memory, cryptic peptides, new views and models of AIDS and autoimmunity, and the shaping of the immune repertoire by early presented antigens and self immunoglobulin.

Rugged fitness landscapes, and emerging area of biological science, underline both molecular and morphological evolution. Mathematical descriptions of such landscapes can be expected to lead to new experimental studies that actually test and establish their structure. In addition, current experimental techniques now allow one to carry out applied molecular evolution in the laboratory, opening up the possibility of evolving biomolecules for medical and industrial use. "Molecular Evolution on Rugged Fitness Landscapes," based on a Santa Fe Institute workshop, is the first book to serve as a comprehensive introduction to these tools that permit researchers to study the structures of complex, rugged, multipeaked fitness landscapes.The first section of the book outlines a number of the general issues concerning the structure of rugged fitness landscapes. The second section examines both the history and status of experimental work on somatic mutation and the maturation of the immune response, and discusses the hypercycle model of the origin of life. This proceedings volume is an excellent reference for graduate students and professionals in immunology, population biology, physics and molecular biology.

The body contains many cellular systems that require the continuous production of new, fully functional, differentiated cells to replace cells lacking or having limited self-renewal capabilities that die or are damaged during the lifetime of an individual. Such systems include the epidermis, the epithelial lining of the gut, and the blood. For example, erythrocytes (red blood cells) lack nuclei and thus are incapable of self-replication. They have a life span in the circulation of about 120 days. Mature granulocytes, which also lack proliferative capacity, have a much shorter life span - typically 12 hours, though this may be reduced to only two or three hours in times of serious tissue infection. Perhaps a more familiar example is the outermost layer of the skin. This layer is composed of fully mature, dead epidermal cells that must be replaced by the descendants of stem cells lodged in lower layers of the epidermis (cf. Alberts et al. , 1983). In total, to supply the normal steady-state demands of cells, an average human must produce approximately 3. 7 x 1011 cells a day throughout life (Dexter and Spooncer, 1987). Common to each of these cellular systems is a primitive (undifferentiated) stem cell which replenishes cells through the production of offspring, some of which proliferate and gradually differentiate until mature, fully functional cells are produced.

Aggregation processes are studied within a number of different fields--c- loid chemistry, atmospheric physics, astrophysics, polymer science, and biology, to name only a few. Aggregation pro ces ses involve monomer units (e. g. , biological cells, liquid or colloidal droplets, latex beads, molecules, or even stars) that join together to form polymers or aggregates. A quantitative theory of aggre- tion was first formulated in 1916 by Smoluchowski who proposed that the time e- lution of the aggregate size distribution is governed by the infinite system of differential equations: (1) K . . c. c. - c k = 1, 2, ...k 1. J 1. J L ~ i+j=k j=l where c is the concentration of k-mers, and aggregates are assumed to form by ir- k reversible condensation reactions [i-mer + j-mer -+ (i+j)-mer]. When the kernel K . . can be represented by A + B(i+j) + Cij, with A, B, and C constant; and the in- 1. J itial condition is chosen to correspond to a monodisperse solution (i. e. , c (0) = 1 0, k > 1), then the Smoluchowski equation can be co' a constant; and ck(O) solved exactly (Trubnikov, 1971; Drake, 1972; Ernst, Hendriks, and Ziff, 1982; Dongen and Ernst, 1983; Spouge, 1983; Ziff, 1984). For arbitrary K , the solution ij is not known and in some ca ses may not even exist.