From a mathematical point of view, physiologically structured population models are an underdeveloped branch of the theory of infinite dimensional dynamical systems. We have called attention to four aspects: (i) A choice has to be made about the kind of equations one extracts from the predominantly verbal arguments about the basic assumptions, and subsequently uses as a starting point for a rigorous mathematical analysis. Though differential equations are easy to formulate (different mechanisms don't interact in infinites imal time intervals and so end up as separate terms in the equations) they may be hard to interpret rigorously as infinitesimal generators. Integral equations constitute an attractive alternative. (ii) The ability of physiologically structured population models to increase our un derstanding of the relation between mechanisms at the i-level and phenomena at the p-level will depend strongly on the development of dynamical systems lab facilities which are applicable to this class of models. (iii) Physiologically structured population models are ideally suited for the for mulation of evolutionary questions. Apart from the special case of age (see Charlesworth 1980, Yodzis 1989, Caswell 1989, and the references given there) hardly any theory exists at the moment. This will, hopefully, change rapidly in the coming years. Again the development of appropriate software may turn out to be crucial.

The purpose of Protein-Protein Recognition is to bring together concepts and systems pertaining to protein-protein interactions in a single unifying volume. In the light of the information from the genome sequencing projects and the increase in structural information it is an opportune time totry to make generalizations about how and why proteins form complexes with each other. The emphasis of the book is on heteromeric complexes (complexes in which each of the components can exist in an unbound state) and will use well-studied model systems to explain the processes of formingcomplexes. After an introductory section on the kinetics, thermodynamics, analysis, and classification of protein-protein interactions, weak, intermediate, and high affinity complexes are dealt with in turn. Weak affinity complexes are represented by electron transfer proteins and integrincomplexes. Anti-lysozyme antibodies, the MHC proteins and their interactions with T-cell receptors, and the protein interactions of eukaryotic signal transduction are the systems used to explain complexes with intermediate affinities. Finally, tight binding complexes are represented by theinteraction of protein inhibitors with serine proteases and by nuclease inhibitor complexes. Throughout the chapters common themes are the technologies which have had the greatest impact, how specificity is determined, how complexes are stabilized, and medical and industrial applications.

The growth and differentiation of living organisms are continuously adjusted to a multitude of environmental factors, each of which underlies a perpetual variation. The sessile existence of plants further emphasizes the requirement for efficient adaptation and defence mechanisms. The changes in environmental factors may range from moderate to dramatic and can concern many components at the same time. They may be abiotic or biotic in nature and range from essential to toxic in their effects. Among the numerous abiotic factors are nutrients, light, oxygen, water, temperature, gravity, wind, touch and chemicals. Biotic factors are represented by other organisms involved in symbiotic, pathogenic or herbivorous interactions with plants. All of these environmental factors are independently and specifically recognized by plants. Perception and overall response are linked by signal transduction pathways at cellular, systemic and interorganismic levels. In order to guarantee proper adaptation to the environment, signals generated following perception of a multitude of environmental factors need to be integrated and evaluated according to their importance. Cross-talk between different signaling pathways within such networks appears to be the basis for the evaluation of the importance of incoming signals. Knowledge of these complex processes allows a better understanding of the molecular mechanisms underlying adaptation. Modulation of distinct signaling elements can generate plants with improved stress resistance. This book represents a comprehensive summary of the enormous amount of information that is now available on signal transduction processes involved in the communication of plants with abiotic and biotic elements of their environment.

The Frontiers in Chemistry Editorial Office team are delighted to present the inaugural “Frontiers in Chemistry: Rising Stars” article collection, showcasing the high-quality work of internationally recognized researchers in the early stages of their independent careers. All Rising Star researchers featured within this collection were individually nominated by the Journal’s Chief Editors in recognition of their potential to influence the future directions in their respective fields. The work presented here highlights the diversity of research performed across the entire breadth of the chemical sciences, and presents advances in theory, experiment and methodology with applications to compelling problems. This Editorial features the corresponding author(s) of each paper published within this important collection, ordered by section alphabetically, highlighting them as the great researchers of the future. The Frontiers in Chemistry Editorial Office team would like to thank each researcher who contributed their work to this collection. We would also like to personally thank our Chief Editors for their exemplary leadership of this article collection; their strong support and passion for this important, community-driven collection has ensured its success and global impact. Laurent Mathey, PhD Journal Development Manager

Biological and biomedical studies have entered a new era over the past two decades thanks to the wide use of mathematical models and computational approaches. A booming of computational biology, which sheerly was a theoretician’s fantasy twenty years ago, has become a reality. Obsession with computational biology and theoretical approaches is evidenced in articles hailing the arrival of what are va- ously called quantitative biology, bioinformatics, theoretical biology, and systems biology. New technologies and data resources in genetics, such as the International HapMap project, enable large-scale studies, such as genome-wide association st- ies, which could potentially identify most common genetic variants as well as rare variants of the human DNA that may alter individual’s susceptibility to disease and the response to medical treatment. Meanwhile the multi-electrode recording from behaving animals makes it feasible to control the animal mental activity, which could potentially lead to the development of useful brain–machine interfaces. - bracing the sheer volume of genetic, genomic, and other type of data, an essential approach is, ?rst of all, to avoid drowning the true signal in the data. It has been witnessed that theoretical approach to biology has emerged as a powerful and st- ulating research paradigm in biological studies, which in turn leads to a new - search paradigm in mathematics, physics, and computer science and moves forward with the interplays among experimental studies and outcomes, simulation studies, and theoretical investigations.

Much of what we know about atoms, molecules, and the nature of matter has been obtained using spectroscopy over the last one hundred years or so. In this book we have collected together twenty chapters by eminent scientists from around the world to describe their work at the cutting edge of molecular spectroscopy. These chapters describe new methodology and applications, instrumental developments, and theory which is taking spectroscopy into new frontiers. The range of topics is broad. Lasers are utilized in much of the research, but their applications range from sub-femtosecond spectroscopy to the study of viruses and also to the investigation of art and archeological artifacts. Three chapters discuss work on biological systems and three others represent laser physics. The recent advances in cavity ringdown spectroscopy (CRDS), surface enhanced Raman spectroscopy (SERS), two-dimensional correlation spectroscopy (2D-COS), and microwave techniques are all covered. Chapters on electronic excited states, molecular dynamics, symmetry applications, and neutron scattering are also included and demonstrate the wide utility of spectroscopic techniques. - Provides comprehensive coverage of present spectroscopic investigations - Features 20 chapters written by leading researchers in the field - Covers the important role of molecular spectroscopy in research concerned with chemistry, physics, and biology