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Books > Science & Mathematics > Biology, life sciences > Zoology & animal sciences > Animal physiology
Themonographisdevotedtothetheoreticalstudiesofradiationeffectsonmammals. It summarizes the results obtained by the author over the past 30 years, most of them being of high priority. In the course of these studies, a single approach to the modeling of radiation effects on mammals has been elaborated. Speci?cally, in the framework of the developed deterministic mathematical models, the effects of both acute and chronic irradiation in a wide range of doses and dose rates on vital body systems (hematopoiesis, small intestine, and humoral immunity), as well as on the development of autoimmune diseases, are investigated. The radiation effects on the mortality dynamics in homogeneous and nonhomogeneous(in radiosensitivity) mammalian populations are also studied by making use of the developed stochastic models. The most appealing feature of these mortality models consists of the fact that they account for the intrinsic properties of the exposed organism. Namely, within these models the stochastic biometrical functions are calculated proceeding from statistical characteristics and dynamics of the respective critical body system (hematopoiesis or small intestine). The performed theoretical investigations contribute to the development of the system and quantitative approaches in radiation biology and ecology. These studies elucidate the major regulatory mechanisms of the damage and recovery processes running in the vital body systems of exposed mammals and reveal the key par- eters characterizing the processes.
Signaling through antigen receptor initiates a complex series of events resulting in the activation of genes that regulate the development, proliferation and differentiation of lymphocytes. During the past few years, rapid progress has been made in understanding the molecular basis of signaling pathways mediated by antigen and cytokine receptors. These pathways involve protein tyrosine kinases which are coupled to downstream regulatory molecules, including small guanine nucleotide binding proteins (e. g. p21'OS), serine threonine kinases (e. g. , members of the ERK family), and a large group of transcription factors. More recently, there have been breakthroughs in elucidating the genetic defects underlying three X-linked primary immunodeficiency diseases in humans. This volume surveys aspects of these rapidly developing areas of research. The book is divided into 5 different sections. Section I deals with signaling pathways in B lymphocytes. It includes a contemporary assessment of B cell antigen receptor structures, and discussion of the role of Ig-a/lg-B polypeptides in linking the antigen receptor to intracellular signal transduction pathways. The role of accessory molecules in the regulation of signaling by the B cell antigen receptor is also considered. Section II adopts a similar approach to the analysis of the antigen receptor on T lymphocytes. The importance of specialized signaling motifs in the CD3 polypeptides, mechanisms whereby these motifs may interact with the lymphocyte-specific protein tyrosine kinases, and the downstream consequences of these interactions are reviewed. In addition, the role of antigen-induced apoptosis in the generation of immunological tolerance is discussed.
Proteins are still gaining importance in the pharmaceutical world, where they are used to improve our arsenal of therapeutic drugs and vaccines and as diagnostic tools. Proteins are different from "traditional" low-molecular-weight drugs. As a group, they exhibit a number of biopharmaceutical and formulation problems. These problems have drawn considerable interest from both industrial and aca demic environments, forcing pharmaceutical scientists to explore a domain previ ously examined only by peptide and protein chemists. Biopharmaceutical aspects of proteins, e.g., low oral bioavailability, have been extensively investigated. Although all possible conventional routes of ad ministration have been examined for proteins, no real, generally applicable alter native to parenteral administration in order to achieve systemic effects has yet been discovered. Several of these biopharmaceutical options have been discussed in Volume 4 of this series, Biological Barriers to Protein Delivery. Proteins are composed of many amino acids, several of which are notorious for their chemical instability. Rational design of formulations that optimize the native structure and/or bioactivity of a protein is therefore of great importance when long shelf life is required, as it is for pharmaceutical products. This issue has also been examined in two prior volumes of this series: Volume 2: Stability of Protein Pharmaceuticals (Part A) and Volume 5: Stability and Characterization of Protein and Peptide Drugs.
Mechanical stress is vital to the functioning of the body, especially for tissues such as bone, muscle, heart, and vessels. It is well known that astronauts and bedridden patients suffer muscle and bone loss from lack of use. Even the heart, in pumping blood, causes mechanical stress to itself and to vascular tissue. With the loss of mechanical stress, homeostasis becomes impaired and leads to pathological conditions such as osteopenia, muscle atrophy, and vascular tissue dysfunction. In elderly populations, such mechanical pathophysiology, as well as the mechanical activities of locomotor and cardiovascular systems, is important because skeletal and heart functions decline and cause diseases in other organs. In this monograph, mechanical stress is discussed by experts in the field with respect to molecular, cellular, and tissue aspects in relation to medicine. Covering topics such as gravity and tissues and disuse osteoporosis, the book provides the most up-to-date information on cutting-edge advancements in the field of mechanobiology and is a timely contribution to research into locomotor and circulatory diseases that are major problems in contemporary society.
In the last decade, research on the previously dormant field of camouflage has advanced rapidly, with numerous studies challenging traditional concepts, investigating previously untested theories and incorporating a greater appreciation of the visual and cognitive systems of the observer. Using studies of both real animals and artificial systems, this book synthesises the current state of play in camouflage research and understanding. It introduces the different types of camouflage and how they work, including background matching, disruptive coloration and obliterative shading. It also demonstrates the methodologies used to study them and discusses how camouflage relates to other subjects, particularly with regard to what it can tell us about visual perception. The mixture of primary research and reviews shows students and researchers where the field currently stands and where exciting and important problems remain to be solved, illustrating how the study of camouflage is likely to progress in the future.
As we approach the twenty-first century the problems of industrialization are evident: we find there is a greenhouse effect, the ozone layer is being depleted, the rain is acidified, and there is a terrible problem of increasing C0 concentrations in the atmo 2 sphere. The carbonic anhydrases are a unique family of enzymes that solve these problems in the human body: they are responsible for converting C0 (a gas) to 2 HC0-, which is the biggest intracellular buffer, with a concomitant decrease in a 3 hydroxyl ion. Globally, the functions of the carbonic anhydrases in photosynthesis in rain forests and in the algae and plankton that cover our oceans indicate that they are also of utmost importance in the maintenance of the acid-base balance on our planet. Although the whole field of C0 metabolism is enormous and still rapidly 2 expanding, because of the research interests of the editors this book is mainly concerned with mammalian carbonic anhydrases. However, if the interested reader intends to purify carbonic anhydrases from nonmammalian sources, Dr. Cheg widden has provided the necessary information in Chapter 7. The carbonic anhydrases were first discovered in 1933; until1976 there were thought to be only two isozymes. Since then CA ill, IY, V, VI, and Vll have been discovered and well characterized. There is, of course, no reason to believe that we have found them all."
The predecessor to this book was A Guide to the Laboratory Use of the Squid Loligo pealei published by the Marine Biological Laboratory, Woods Hole, Massachusetts in 1974. The revision of this long out of date guide, with the approval of the Marine Biological Laboratory, is an attempt to introduce students and researchers to the cephalopods and particularly the squid as an object of biological research. Therefore, we have decided to expand on its original theme, which was to present important practical aspects for using the squid as experimental animals. There are twenty two chapters instead of the original eight. The material in the original eight chapters has been completely revised. Since more than one method can be used for accomplishing a given task, some duplication of methods was considered desirable in the various chapters. Thus, the methodology can be chosen which is best suited for each reader's requirements. Each subject also contains a mini-review which can serve as an introduction to the various topics. Thus, the volume is not just a laboratory manual, but can also be used as an introduction to squid biology. The book is intended for laboratory technicians, advanced undergraduate students, graduate students, researchers, and all others who want to learn the purpose, methods, and techniques of using squid as experimental animals. This is the reason why the name has been changed to its present title. Preceding the chapters is a list of many of the abbreviations, prefixes, and suffixes used in this volume.
Here is the first effort in a single volume to cover all of the integrative functions of calcium signalling - how changes in intracellular calcium coordinate a variety of coherent cellular responses. Written by a team of internationally established researchers, Integrative Aspects of Calcium Signalling provides the latest experimental data and concepts, bringing together a detailed analysis of the events, processes, and functions regulated by calcium signalling. A unique resource for professionals and students of physiology, biophysics, neurobiology, biochemistry, and all related fields.
How does the brain code and process incoming information, how does it recog nize a certain object, how does a certain Gestalt come into our awareness? One of the key issues to conscious realization of an object, of a Gestalt is the attention de voted to the corresponding sensory input which evokes the neural pattern underly ing the Gestalt. This requires that the attention be devoted to one set of objects at a time. However, the attention may be switched quickly between different objects or ongoing input processes. It is to be expected that such mechanisms are reflected in the neural dynamics: Neurons or neuronal assemblies which pertain to one object may fire, possibly in rapid bursts at a time. Such firing bursts may enhance the synaptic strength in the corresponding cell assembly and thereby form the substrate of short-term memory. However, we may well become aware of two different objects at a time. How can we avoid that the firing patterns which may relate to say a certain type of move ment (columns in V5) or to a color (V 4) of one object do not become mixed with those of another object? Such a blend may only happen if the presentation times be come very short (below 20-30 ms). One possibility is that neurons pertaining to one cell assembly fire syn chronously. Then different cell assemblies firing at different rates may code different information."
In the past few years, the scientific community has witnessed significant progress in the study of ion channels. Technological advancement in biophysics, molecular biology, and immunology has been greatly ac celerated, making it possible to conduct experiments which were deemed very difficult if not impossible in the past. For example, patch-clamp techniques can now be used to measure ionic currents generated by almost every type of cell, thereby allowing us to analyze whole-cell and single channel events. It is now possible to incorporate purified ion channel components into lipid bilayers to reconstitute an "excitable membrane." Gene cloning and monoclonal antibody techniques provide us with new approaches to the study of the molecular structure of ion channels. A variety of chemicals have now been found to interact with ion channels. One of the classical examples is represented by tetrodotoxin, a puffer fish poison, which was shown in the early 1960s to block the voltage-activated sodium channel in a highly specific and potent manner.
Although there is general agreement that exogenous electric and electromagnetic fields influence and modulate the properties of biological systems. there is no concensus regarding the mechanisms by which such fields operate. It is the purpose of this volume to bring together and examine critically the mechanistic models and concepts that have been proposed. We have chosen to arrange the papers in terms of the level of biological organization emphasized by the contributors. Some papers overlap categories. but the progression from ions and membrane surfaces. through macromolecules and the membrane matrix to integrated systems. establishes a mechanistic chain of causality that links the basic interactions in the relatively well understood simple systems to the complex living systems. where all effects occur simultaneously. The backgrounds of the invited contributors include biochemistry. biophysics. cell biology. electrical engineering. electrochemistry. electrophysiology. medicine and physical chemistry. As a result of this diversity. the mechanistic models reflect the differing approaches used by these disciplines to explain the same phenomena. Areas of agreement define the common ground. while the areas of divergence provide opportunities for refining our ideas through further experimentation. To facilitate the interaction between the different points of view, the authors have clearly indicated those published observations that they are trying to explain. i.e. the experiments that have been critical in their thinking. This should establish a concensus regarding important observations. In the discussion of theories.
William P. Cooney III, R. A. Berger, and K. N. An Orthopedic Biomechanics Laboratory Department of Orthopedic Surgery Mayo Clinic and Mayo Foundation Rochester, MN 55905, U. S. A. As surgeons struggle to find new insights into the complex diseases and deformities that involve the wrist and hand, new insights are being provided by applied anatomy, physiology and biomechanics to these important areas. Indeed, a fresh new interaction of disciplines has immersed in which anatomists, bioengineers and surgeons examine together basic functions and principles that can provide a strong foundation for future growth. Clinical interest in the hand and wrist are now at a peak on an international level. Economic implications of disability affecting the hand and wrist are recognized that have international scope crossing oceans, cultures, languages and political philosophies. As with any struggle, a common ground for understanding is essential. NATO conferences such as this symposium on Biomechanics of the Hand and Wrist provides such a basis upon which to build discernment of fundamental postulates. As a start, basic research directed at studies of anatomy, pathology and pathophysiology and mechanical modeling is essential. To take these important steps further forward, funding from government and industry are needed to consider fundamental principles within the material sciences, biomechanical disciplines, applied anatomy and physiology and concepts of engineering modeling that have been applied to other areas of the musculoskeletal system.
In recent years experimental and numerical studies have shown that chaos is a widespread phenomenon throughout the biological hierarchy ranging from simple enzyme reactions to ecosystems. Although a coherent picture of the fundamental mechanisms responsible for chaotic dynamics has started to appear it is not yet clear what the implications of such dynamics are for biological systems in general. In some systems it appears that chaotic dynamics are associated with a pathological condi tion. In other systems the pathological condition has regular periodic dynamics whilst the normal non-pathological condition has chaotic dyna mics. Since chaotic behaviour is so ubiquitous in nature and since the phenomenon raises some fundamental questions about its implications for biology it seemed timely to organize an interdisciplinary meeting at which leading scientists could meet to exchange ideas, to evaluate the current state of the field and to stipulate the guidelines along which future research should be directed. The present volume contains the contributions to the NATO Advanced Research Workshop on "Chaos in Biological Systems" held at Dyffryn House, St. Nicholas, Cardiff, U. K., December 8-12, 1986. At this meeting 38 researchers with highly different backgrounds met to present their latest results through lectures and posters and to discuss the applica tions of non-linear techniques to problems of common interest. . In spite of their involvement in the study of chaotic dynamics for several years many of the participants met here for the first time."
I have been asked to write a brief foreword to this volume honoring Hisako Ikeda, providing a review of the accomplishments in our field over the past four decades, when Hisako was an active participant. This I am delighted to do. It has been a most exciting time in vision research and Hisako has been right in the middle of much of the excitement, publishing on a wide variety of topics and providing much new data and many new insights. Hisako's research career can be divided by decades into four quite distinct areas of inquiry. In the 1950s, as a student in Japan, her research interests were psychophysical in nature, and she was concerned with visual illusions, figural aftereffects, and motion detec tion. In the 1960s, after her move to London, she began electrophysiological studies. Much of her work in the 1960s was concerned with the electroretinogram (ERG), its components, and the use of this electrical response for evaluating spectral sensitivities of the eye and retinal degenerations. This work represented the beginning of her electrodiagnostic clinical work, which continued until her retirement."
This text attempts to introduce the molecular biology of cell membranes to students and professionals of diverse backgrounds. Although several membrane biology books are available, they do not integrate recent knowledge gained using modern molecular tools with more traditional membrane topics. Molecular techniques, such as cDNA cloning and x-ray diffraction, have provided fresh insights into cell membrane structure and function. The great excitement today, which I attempt to convey in this book, is that molecular details are beginning to merge with physiological responses. In other words, we are beginning to understand precisely how membranes work. This textbook is appropriate for upper-level undergraduate or beginning graduate students. Readers should have previous or concurrent coursework in biochemistry; prior studies in elementary physiology would be helpful. I have found that the presentation of topics in this book is appropriate for students of biology, biochemistry, biophysics and physiology, chemistry, and medicine. This book will be useful in courses focusing on membranes and as a supplementary text in biochemistry courses. Professionals will also find this to be a useful resource book for their personal libraries.
Since programmed cell death was first described in insects in 1964 and apoptosis was described in 1972, rapid progress has been made in understanding the basic mechanisms and genes regulating programmed cell death and apoptosis. In addition, defects in various genes regulating programmed cell death have been delineated in several experimental models of human diseases. This volume surveys various aspects of these rapidly developing areas of research in programmed cell death/apoptosis. This volume should be of interest to basic immunologists and molecular biologists. The volume begins with a historical perspective of cell death. The remainder of the volume is divided into four different parts. Part I deals with the signaling pathways in apoptosis, including cell cycle control of apoptosis, role of ceramide in apoptosis, role of antibody signaling, and biochemical regulation of apoptosis. The mechanisms for recognition of apoptotic lymphocytes by macrophages are also reviewed. Part II examines the role of various genes that regulate apoptosis, including the role ofFas, FasL, and other TNF family members in apoptosis and homeostatic regulation of immune response. Recently described splice variants and their influence on apoptosis are also reviewed, and the role of the members of the Bcl-2 family in apoptosis is discussed in detail. Part III reviews various aspects of apoptosis in B lymphocytes, including mechanisms that regulate apoptosis/survival of B lymphocytes and the regulation of Fas-mediated apoptosis in B lymphocytes.
The past decade has seen a steady increase in studies oflemur behavior and ecology. As a result, there is much novel information on newly studied populations, and even newly discovered species, that has not yet been published or summarized. In fact, lemurs have not been the focus of an international symposium since the Prosimian Biology Conference in London in 1972. Moreover, research on lemurs has reached a new quality by addressing general issues in behavioral ecology and evolutionary biology. Although lemurs provide important comparative information on these topics, this aspect of research on lemurs has not been reviewed and compared with similar studies in other primate radiations. Thus, as did many in the field, we felt that the time was ripe to review and synthesize our knowledge of lemur behavioral ecology. Following an initiative by Gerry Doyle, we organized a symposium at the XIVth Congress of the International Primatological Society in Strasbourg, France, where 15 contributions summarized much new information on lemur social systems and their ecological basis. This volume provides a collection of the papers presented at the Strasbourg symposium (plus two reports from recently completed field projects). Each chapter was peer-reviewed, typically by one "lemurologist" and one other biologist. The first three chapters present novel information from the first long-term field studies of three enigmatic species. Sterling describes the social organization of Daubentonia madagascariensis, showing that aye-aye ranging patterns deviate from those of all other nocturnal primates.
This book focuses on sensing and the evolution of animals. Using the five senses (visual, auditory, and olfactory perception, and taste and touch), animals can receive environmental stimuli and respond to them. Changes in these sensitivities might cause changes in aspects of animals lives such as habitat, activity timing, and diet and vice versa. Recent advances in genome and molecular analysis enable us to investigate certain changes in the receptors or mechanisms involved in sensing and provide clues for understanding the evolution of animals related to those changes. The first chapter deals with the molecular evolution of opsins. In addition to the well-known function of opsins as visual receptors, opsins can be related to non-visual photoreception such as photoentrainment of circadian rhythm, photoperiodism, and background adaptation. Molecular phylogenic studies reveal that all opsin genes have evolved from one ancient opsin gene. The evaluation of the functions of each extant opsin protein based on the molecular features enables us to predict the molecular evolution and diversification of opsins during the evolution of animals. These studies shed light on which amino-acid substitutions cause the functional diversification of opsins and how they have influenced the evolution of animals. The second chapter has to do with bitter taste perception, a key detection mechanism against the ingestion of bioactive substances. Genetic and behavioral evidence reveal the existence of "non-taster" Japanese macaques for specific bitter compounds, which originated in a restricted region of Japan. This finding might provide a clue for elucidating the ecological, evolutionary, and neurobiological aspects of bitter taste perception of primates. The third chapter presents an extreme example of the evolution of olfaction, namely, that fully aquatic amniotes have generally reduced their olfactory capacity considerably compared to their terrestrial relatives. Interestingly, the remaining olfactory abilities are quite different among three fully aquatic amniotes investigated: toothed whales have no nervous system structures that mediate olfaction, but baleen whales can smell in air, and it has been suggested that sea snakes smell underwater."
In this introductory text, Dr. Birdi demonstrates experimental methods and analyses of fractal dimensions in natural processes. In addition to a general overview, he discusses in detail problems in the fields of chemistry, geochemistry, and biophysics. Both students and professionals with a minimum of mathematics or physical science training will learn to find and model shapes and patterns from their own everyday observations.
Proceedings of a NATO ARW held in Cargese, France, October 9-13, 1989
This comprehensive treatise on the reticuloendothelial system is a project jointly shared by individual members of the Reticuloendothelial (RE) Society and bio- medical scientists in general who are interested in the intricate system of cells and molecular moieties derived from those cells that constitute the RES. It may now be more fashionable in some quarters to consider these cells as part of what is called the mononuc1ear phagocytic system or the lymphoreticular system. Nevertheless, because of historical developments and current interest in the subject by investigators from many diverse areas, it seems advantageous to present in one comprehensive treatise current information and knowledge con- cerning basic aspects of the RES, such as morphology, biochemistry, phylogeny and ontogeny, physiology, and pharmacology, as well as c1inical areas inc1uding immunopathology, cancer, infectious diseases, allergy, and hypersensitivity. It is anticipated that, by presenting information concerning these apparently het- erogeneous topics under the unifying umbrella of the RES, attention will be focused on the similarities as well as interactions among the cell types constitut- ing the RES from the viewpoint of various disciplines. The treatise editors and their editorial board, consisting predominantly of the editors of individual vol- umes, are extremely grateful for the enthusiastic cooperation and enormous task undertaken by members of the biomedical community in general and especially by members of the American as well as European and Japanese Reticuloen- dothelial Societies.
This book was originated from a series of lectures given in a course on the physical properties of biological membranes and their functional implica tions. The course was intended to allow students to get acquainted with the physical techniques used to study biological membranes. The experience was valuable and we feel that a detailed description of the procedures used and of various examples of the results obtained allowed many students to become familiar with a theme that is not often part of regular courses on membrane physiology or biophysics. This book is designed as a tutorial guide for graduate students interested in understanding how physical methods can be utilized to study the proper ties of biological membranes. It includes first a detailed description of applications of physical techniques-such as X-ray fiber diffraction methods (Chapter 1), 2H and 13C NMR spectroscopy (Chapter 2), and calorimetry (Chapter 3)-in the study of the properties of lipid model membranes. A description of how to measure molecular mobility in membranes (Chapter 4) follows, and the book concludes with three chapters in which biological membranes are the subject of study. Chapter 5 deals with the acetylcholine receptor and its membrane environment; Chapter 6 discusses how fluorescence techniques can be applied in the study of the calcium ATPase of sarcoplasmic reticulum; and Chapter 7 explains how protein lipid interactions modulate the function of the sodium and proton pumps."
This is a book about how Cl- crosses the cell membranes of nerve, muscle, and glial cells. Not so very many years ago, a pamphlet rather than book might have resulted from such an endeavor! One might ask why Cl-, the most abundant biological anion, attracted so little attention from investigators. The main reason was that the prevailing paradigm for cellular ion homeostasis in the 1950s and 1960s assigned Cl- a ther modynamically passive and unspecialized role. This view was particularly prominent among muscle and neuroscience investigators. In searching for reasons for such a negative (no pun intended) viewpoint, it seems to us that it stemmed from two key experimental observations. First, work on frog skeletal muscle showed that Cl- was passively distributed between the cytoplasm and the extracellular fluid. Second, work on Cl- transport in red blood cells confirmed that the Cl- transmembrane distribution was thermodynamically passive and, in addition, showed that Cl- crossed the mem brane extremely rapidly. This latter finding [for a long time interpreted as being the result of a high passive chloride electrical permeability(? CI)] made it quite likely that Cl- would remain at thermodynamic equilibrium. These two observations were gener alized and virtually all cells were thought to have a very high P Cl and a ther modynamically passive Cl- transmembrane distribution. These concepts can still be found in some physiology and neuroscience textbooks. |
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