Green Equilibrium

In Green Equilibrium, Christopher Wills explains the rules by which ecosystems maintain a diversity of interdependent species, in particular the balance of predators and prey. Wills is both an eminent academic and a hugely experienced field-biologist. In presenting the concept of 'green equilibrium', he draws on a fascinating range of examples, including coral reefs off the densely populated Philippines, the isolated and densely forested valleys of Papua New Guinea, the changing Himalayan kingdom of Bhutan, and a Californian ranch being allowed to return to a wild state. In each case he assesses the impact of modern changes and attempts at conservation on these delicately balanced ecosystems. Wills shows how human populations, too, are an integral part of the picture. We now know from genetic evidence that over the course of history, as humans spread out of Africa, populations adapted as a result of environmental conditions. Striking new evidence indicates that some human populations carry genes from past encounters with other hominids (Neanderthals and Denisovans), as well as genetic adaptations to local hazards such as malaria. Wills argues that the most effective approaches to conserving green equilibria come out of evolutionary insights, and from close involvement of the local communities who have lived and adapted to them.

For modeling the transport of carriers in nanoscale devices, a Green-function formalism is the most accurate approach. Due to the complexity of the formalism, one should have a deep understanding of the underlying principles and use smart approximations and numerical methods for solving the kinetic equations at a reasonable computational time. In this book the required concepts from quantum and statistical mechanics and numerical methods for calculating Green functions are presented. The Green function is studied in detail for systems both under equilibrium and under nonequilibrium conditions. Because the formalism enables rigorous modeling of different scattering mechanisms in terms of self-energies, but an exact evaluation of self-energies for realistic systems is not possible, their approximation and inclusion in the quantum kinetic equations of the Green functions are elaborated. All the elements of the kinetic equations, which are the device Hamiltonian, contact self-energies and scattering self-energies, are examined and efficient methods for their evaluation are explained. Finally, the application of these methods to study novel electronic devices such as nanotubes, graphene, Si-nanowires and low-dimensional thermoelectric devices and photodetectors are discussed.

How do ecological and evolutionary factors maintain the balance of diverse species (including humans) in an ecosystem? With examples ranging from Bhutan to California, Christopher Wills explains the processes. He also presents striking evidence that human populations have adapted genetically to environments.

Equilibrium and nonequilibrium properties of correlated many-body systems are of growing interest in many areas of physics, including condensed matter, dense plasmas, nuclear matter and particles. The most powerful and general method which is equally applied to all these areas is given by quantum field theory. This book provides an overview of the basic ideas and concepts of the method of nonequilibrium Green''s functions, written by the leading experts and presented in a way accessible to non-specialists and graduate students. It is complemented by invited review papers on modern applications of the method to a variety of topics, such as optics and quantum transport in semiconductors; superconductivity; strong field effects, QCD, and state-of-the-art computational concepts OCo from Green''s functions to quantum Monte Carlo and time-dependent density functional theory.The proceedings have been selected for coverage in: OCo Index to Scientific & Technical Proceedings (ISTP CDROM version / ISI Proceedings)"

Understanding basin-fill evolution and the origin of stratal architectures has traditionally been based on studies of outcrops, well and seismic data, studies of and inferences on qualitative geological processes, and to a lesser extent based on quantitative observations of modern and ancient sedimentary environments. Insight gained on the basis of these studies can increasingly be tested and extended through the application of numerical and analogue forward models. Present-day stratigraphic forward modelling follows two principle lines: 1) the deterministic process-based approach, ideally with resolution of the fundamental equations of fluid and sediment motion at all scales, and 2) the stochastic approach. The process-based approach leads to improved understanding of the dynamics (physics) of the system, increasing our predictive power of how systems evolve under various forcing conditions unless the system is highly non-linear and hence difficult or perhaps even impossible to predict. The stochastic approach is more direct, relatively simple, and useful for study of more complicated or less-well understood systems. Process-based models, more than stochastic ones, are directly limited by the diversity of temporal and spatial scales and the very incomplete knowledge of how processes operate and interact on the various scales. The papers included in this book demonstrate how cross-fertilization between traditional field studies and analogue and numerical forward modelling expands our understanding of Earth-surface systems.

Colour has long been a source of fascination to both scientists and philosophers. In one sense, colours are in the mind of the beholder, in another sense they belong to the external world. Colours appear to lie on the boundary where we have divided the world into 'objective' and 'subjective' events. They represent, more than any other attribute of our visual experience, a place where both physical and mental properties are interwoven in an intimate and enigmatic way. The last few decades have brought fascinating changes in the way that we think about 'colour' and the role 'colour' plays in our perceptual architecture. In Colour Perception: Mind and the physical world, leading scholars from cognitive psychology, philosophy, neurophysiology, and computational vision provide an overview of the contemporary developments in our understanding of colours and of the relationship between the 'mental' and the 'physical'. With each chapter followed by critical commentaries, the volume presents a lively and accessible picture of the intellectual traditions which have shaped research into colour perception. Written in a non-technical style and accessible to an interdisciplinary audience, the book will provide an invaluable resource for researchers in colour perception and the cognitive sciences.

This book presents a state-of-the-art scientific overview of the influence of terrestrial vegetation and soils within the Earth system. It deals especially with interactions between the terrestrial biosphere and the atmosphere via the hydrological cycle and their interlinkage with anthropogenic activities. Measurements gathered in integrated field experiments in the Sahel, the Amazon, North America and South-east Asia confirm the importance of these interactions, but a substantial data consolidation effort still needs to be undertaken. Observations are complemented by modelling studies, including regional models that simulate flows and transport in river catchments, coupled land-cover and regional climate systems, and Earth-system and global circulation models. Water, nutrient and sediment fluxes in river basins are also discussed and are shown to be highly impacted and regulated by humans through land use, pollution and river engineering. Finally, the book discusses environmental vulnerability and methodologies for assessing the risks associated with regional and global climatic and environmental variability and change.The editors emphasise that the results reported in this book are based on the research work of many individual scientists and teams around the world associated with the objectives of the IGBP-BAHC and WCRP-GEWEX international research programmes.