Hans Degn – författare

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.

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.

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.

Functions of Alternative Terminal Oxidases is a collection of papers from the 11th meeting of the Federation of European Biochemical Societies in Copenhagen in 1977. The book opens with a review of the alternate electron transport mechanism to the main phosphorylating respiratory chain. One paper presents the respiration of mutant stains of Neurospora crassa treated with chloramphenicol that results in three distinct pathways distinguishable by the use of inhibitors. Another paper outlines the testing methods to determine the parameters controlling cyanide-insensitive respiration in Acanthamoeba castellanii and notes the physiological function of this insensitivity. The book then explains that this phenomenon of cyanide-insensitive respiration is common among yeasts, and such pathway of electron transport to oxygen that is insensitive to cyanide or antimycin is well founded in many higher plants and microorganisms. One paper then investigates the terminal oxidases found in two stages in the life cycle of trypanosomes, which cause African sleeping sickness. Another paper notes that a study of the energy metabolism of End. magnusii, a kind of yeast, showed no glucose repression, no alternative oxidation pathway, and no cyanide-insensitive pathway was normally present. The text will be of interest to those whose work involves these organisms, and to researchers, professors, and students whose disciplines are in developmental biology, micro-biology, or cellular biology.

Being small, shapeless and inert a gas molecule does not seem to be an enzyme''s dream of a substrate. Nevertheless evolution has provided a host of enzymes which can interact specifically with gas molecules such as oxygen, carbon dioxide, nitrogen, hydrogen etc. Many of these enzymes play dominant roles on the world scene in biogeochemical cycles. On the cellular level they tend to be closely connected to the energy conserving apparatus. We define Gas Enzymology as the study of these enzymes. Historically, Gas Enzymology is a subspecialty of bioenergetics. Its foundations, technical as well as conceptual were laid by Warburg in his studies of the cellular combustion of nutrients. The Warburg apparatus supported the first thirty years of research in the field. It was succeeded by the Clark electrode which had its heyday during the period when the modern concepts of bioenergetics took shape. The Clark electrode, itself approaching thirty years of age, is now being sup­ plemented and in some cases replaced by the vastly more powerful membrane inlet mass spectrometer which measures with equal ease all dis­ solved gases of interest in biochemistry. It is our belief that future development of Gas Enzymology will be linked to the widespread exploit­ ation of this technique.