The transduction of signals from the extracellular space across the plasma membrane into the interior of cells and ultimately to the nucleus, where in - sponse to such external signals the transcription of the genetic code is inf- enced,belongs to the most fundamental and important events in the regulation of the life cycle of cells. During recent years several signal transduction cascades have been elucidated which regulate,for instance,the growth and the prolife- tion of organisms as diverse as mammals, flies, worms and yeast. The general picture which emerged from these investigations is that nature employs a c- bination of non-covalent ligand/protein and protein/protein interactions together with a set of covalent protein modifications to generate the signals and transduce them to their destinations. The ligands which are recognized may be low molecular weight compounds like lipids, inositol derivatives, steroids or microbial products like cyclosporin. They may be proteins like, for instance, growth factors or intracellular adaptor proteins which carry SH2 or SH3 domains, and they may be specific DNA stretches which are selectively rec- nized by transcription factors. These and other aspects of biological signal transduction provide an open and rewarding field for investigations by scientists from various different dis- plines of biology,medical research and chemistry working in academic research institutions or in industry.

"Photophysics of Carbon Nanotubes Interfaced with Organic and Inorganic Materials "describes physical, optical and spectroscopic properties of the emerging class of nanocomposites formed from carbon nanotubes (CNTs) interfacing with organic and inorganic materials.

The three main chapters detail novel trends in photophysics related to the interaction of light with various carbon nanotube composites from relatively simple CNT/small molecule assemblies to complex hybrids such as CNT/Si and CNT/DNA nanostructures. The latest experimental results are followed up with detailed discussions and scientific and technological perspectives to provide a through coverage of major topics including:

-Light harvesting, energy conversion, photoinduced charge separation and transport in CNT based nanohybrids

-CNT/polymer composites exhibiting photoactuation; and

-Optical spectroscopy and structure of CNT/DNA complexes.

Including original data and a short review of recent research, "Photophysics of Carbon Nanotubes Interfaced with Organic and Inorganic Materials" makes this emerging field of photophysics and its applications available to academics and professionals working with carbon nanotube composites in fundamental and applied fields

Photophysics of Carbon Nanotubes Interfaced with Organic and Inorganic Materials describes physical, optical and spectroscopic properties of the emerging class of nanocomposites formed from carbon nanotubes (CNTs) interfacing with organic and inorganic materials. The three main chapters detail novel trends in photophysics related to the interaction of light with various carbon nanotube composites from relatively simple CNT/small molecule assemblies to complex hybrids such as CNT/Si and CNT/DNA nanostructures. The latest experimental results are followed up with detailed discussions and scientific and technological perspectives to provide a through coverage of major topics including: -Light harvesting, energy conversion, photoinduced charge separation and transport in CNT based nanohybrids -CNT/polymer composites exhibiting photoactuation; and -Optical spectroscopy and structure of CNT/DNA complexes. Including original data and a short review of recent research, Photophysics of Carbon Nanotubes Interfaced with Organic and Inorganic Materials makes this emerging field of photophysics and its applications available to academics and professionals working with carbon nanotube composites in fundamental and applied fields

The transduction of signals from the extracellular space across the plasma membrane into the interior of cells and ultimately to the nucleus, where in - sponse to such external signals the transcription of the genetic code is inf- enced,belongs to the most fundamental and important events in the regulation of the life cycle of cells. During recent years several signal transduction cascades have been elucidated which regulate,for instance,the growth and the prolife- tion of organisms as diverse as mammals, flies, worms and yeast. The general picture which emerged from these investigations is that nature employs a c- bination of non-covalent ligand/protein and protein/protein interactions together with a set of covalent protein modifications to generate the signals and transduce them to their destinations. The ligands which are recognized may be low molecular weight compounds like lipids, inositol derivatives, steroids or microbial products like cyclosporin. They may be proteins like, for instance, growth factors or intracellular adaptor proteins which carry SH2 or SH3 domains, and they may be specific DNA stretches which are selectively rec- nized by transcription factors. These and other aspects of biological signal transduction provide an open and rewarding field for investigations by scientists from various different dis- plines of biology,medical research and chemistry working in academic research institutions or in industry.

The aim of this monograph is to summarize the essential features which characterize the behavior of regulatory systems. Firstly we discuss the laws which govern ligand binding in thermodynamic terms. The basic cooperative and allosteric phenomena are des cribed in thermodynamic terms without assuming any particular mo del. Then the molecular models developed by Monod, Wyman and Changeux and by Koshland, Nemethy and Filmer are presented in detail. Special emphasis has been given to the analysis of the Hill coefficient and its meaning both in thermodynamic terms and in terms of the two allosteric models: the concerted model of Monod, Wyman and Changeux and the sequential model of Koshland, Nemethy and Filmer. Special types of cooperativities are dis cussed in some detail namely, cooperativity stemming from ligand coupled protein association or dissociation, negative cooperati vity and half-of-the-sites reactivity. A slightly extended space was devoted to the discussion of negative cooperativity and half of-the-sites reactivity, since the existence of these phenomena and their possible biological importance is less of a common knowledge than positive cooperativity. This monograph does not attempt to be a review of specific examples analyzed according to one model or another. Rather, an attempt is made to provide the reader with the quantitative tools to analyze any specific regulatory system. Last but not least, I would like to thank Prof. F. W. Dahlquist from the Institute of Molecular Biology, the University of Oregon (Eugene) and Prof. D. E. Koshland, Jr."