Bücher veröffentlicht von Springer Netherlands

The nutrient dynamics and biological structure of shallow non-stratified lakes differ markedly from that of deep and stratified lakes: for example, the return of nutrients lost through sedimentation is faster and the potential importance of fish and submerged macrophytes as food-web regulators is greater. In addition shallow lakes are more easily influenced by fluctuations in the physical environment caused by wind disturbance, temperature change, etc. Although shallow lakes are often the most common lake type in lowland countries, less attention has been paid to them than to deep stratified lakes and few comparisons have been made between shallow freshwater and brackish lakes. The volume is divided into five main themes, each introduced by an invited speaker: Nutrient dynamics with special emphasis on sediment water interactions and changes in loading (Professor Lambertus Lyklema); Biological structure and trophic interaction (Professor Stephen T. Threlkeld); Submerged macrophytes: dynamics and role in the lake ecosystems (Ass. Professor Kaj Sand Jensen); Comparison of freshwater and brackish lake ecosystems (Professor Brian Moss); Modelling the impact of nutrients, the biological structure and the recovery process (Dr Marten Scheffer).

In January 1992, the Sixth Workshop on Optimization and Numerical Analysis was held in the heart of the Mixteco-Zapoteca region, in the city of Oaxaca, Mexico, a beautiful and culturally rich site in ancient, colonial and modern Mexican civiliza- tion. The Workshop was organized by the Numerical Analysis Department at the Institute of Research in Applied Mathematics of the National University of Mexico in collaboration with the Mathematical Sciences Department at Rice University, as were the previous ones in 1978, 1979, 1981, 1984 and 1989. As were the third, fourth, and fifth workshops, this one was supported by a grant from the Mexican National Council for Science and Technology, and the US National Science Foundation, as part of the joint Scientific and Technical Cooperation Program existing between these two countries. The participation of many of the leading figures in the field resulted in a good representation of the state of the art in Continuous Optimization, and in an over- view of several topics including Numerical Methods for Diffusion-Advection PDE problems as well as some Numerical Linear Algebraic Methods to solve related pro- blems. This book collects some of the papers given at this Workshop.

This volume contains papers presented either in oral or poster form at the international symposium `Limnology of Mountain Lakes', held at Stara Lesna (Slovakia) between 1 and 7 July 1991. Several papers covered contributions from the fields of physical and chemical limnology, palaeolimnology, zooplankton, phytoplankton and phytobenthos, and bacteria. Acidification, a process affecting water chemistry and biota of many mountain lakes in Europe was dealt with also. A series of papers on the lakes in Sumava has highlighted different aspects of these lakes, which are in the last stage of acidification. Other geographical areas covered extensively were the Tatras and the Alps.

Plant Cell and Tissue Culture gives an exhaustive account of plant cell culture and genetic transformation, including detailed chapters on all major field and plantation crops. Part A presents a comprehensive coverage of all necessary laboratory techniques for the initiation, nutrition, maintenance and storage of plant cell and tissue cultures, including discussions on these topics, as well as on morphogenesis and regeneration, meristem and shoot tip culture, plant protoplasts, mutant cell lines, variation in tissue cultures, isogenic lines, fertilization control, cryopreservation, transformation, and the production of secondary metabolites. Part B then proceeds into detail on the specific in vitro culture of specific crops, including cereals, legumes, vegetables, potatoes, other roots and tubers, oilseeds, temperate fruits, tropical fruits, plantation crops, forest trees and ornamentals. Plant Cell and Tissue Culture is, and is likely to remain, the laboratory manual of choice, as well as a source of inspiration and a guide to all workers in the field.

The use of numerical grid methods to solve the Schrodinger equation has rapidly evolved in the past decade.The early attempts to demonstrate the computational viability of grid methods have been largely superseded by applications to specific problems and deeper research into more sophisticated quadrature schemes. Underpinning this research, of course, is the belief that the generic nature of grid methods can enjoy a symbiotic development with advances in computer technology, harnessing this technology in an effective manner. The contributions to this proceedings demonstrate these points in full: several appli- cations displayed creative use and extension of existing grid methodology; other research concentrated on the development of new quadrature schemes or mixed numerical meth- ods. The research represented ranges from highly specific spectral simulations of van der Waals complexs to general schemes for reactive scattering. The novelty of grid methods in Density Functional Theory calculations should also be highlighted since it represents an alternative to standard basis set expansion techniques and might offer distinct advantages to the standard techniques. A deliberate attempt was made to present research material with more motivational and background discussion than is typical of research publications. It is hoped that these contributed proceedings will be useful to students and researchers outside the field to have a rapid and complete introduction to many of the exciting uses of grid methodology in atomic and molecular physics. Special thanks are due to the NATO Science Committee for its generous support of the activities of this workshop.

The last thirty years were a period of continuous and intense growth in the subject of dynamical systems. New concepts and techniques and at the same time new areas of applications of the theory were found. The 31st session of the Seminaire de Mathematiques Superieures (SMS) held at the Universite de Montreal in July 1992 was on dynamical systems having as its center theme "e;Bifurcations and periodic orbits of vector fields"e;. This session of the SMS was a NATO Advanced Study Institute (ASI). This ASI had the purpose of acquainting the participants with some of the most recent developments and of stimulating new research around the chosen center theme. These developments include the major tools of the new resummation techniques with applications, in particular to the proof of the non-accumulation of limit-cycles for real-analytic plane vector fields. One of the aims of the ASI was to bring together methods from real and complex dy- namical systems. There is a growing awareness that an interplay between real and complex methods is both useful and necessary for the solution of some of the problems. Complex techniques become powerful tools which yield valuable information when applied to the study of the dynamics of real vector fields. The recent developments show that no rigid frontiers between disciplines exist and that interesting new developments occur when ideas and techniques from diverse disciplines are married. One of the aims of the ASI was to show these multiple interactions at work.