Control of polymeric structure is among the most important endeavours of modern macromolecular science. In particular, tailoring the positioning and strength of intermolecular forces within macromolecules by synthetic me- odsandthusgaining structuralcontrolover the?nalpolymeric materials has become feasible, resulting in the ?eld of supramolecular polymer science. - sides other intermolecular forces, hydrogen bonds are unique intermolecular forces enabling the tuning of material properties via self-assembly processes -1 overawiderangeofinteractionstrengthrangingfromseveralkJmol tosev- -1 eraltensofkJmol . Centralfortheformationofthesestructuresareprecursor molecules of small molecular weight (usually lower than 10 000), which can assembleinsolidorsolutiontoaggregatesofde?nedgeometry. Intermolecular hydrogenbondsatde?nedpositionsofthesebuildingblocksaswellastheir- spectivestartinggeometryandtheinitialsizedeterminethemodeofassembly into supramolecular polymers forming network-, rodlike-, ?brous-, disclike- , helical-, lamellar- and chainlike architectures. In all cases, weak to strong hydrogen-bondinginteractionscanactasthecentralstructure-directingforce fortheorganizationofpolymerchainsandthusthe?nalmaterials'properties. Theimportantcontributionofhydrogenbondstotheareaofsupramole- lar polymer chemistry is de?nitely outstanding, most of all since the potency of hydrogen-bonding systems has been found to be unique in relation to other supramolecular interactions. Thus the high level of structural diversity of many hydrogen-bonding systems as well as their high level of direction- ity and speci?city in recognition-phenomena is unbeaten in supramolecular chemistry. The realization, that their stability can be tuned over a wide range of binding strength is important for tuning the resulting material prop- ties, ranging from elastomeric to thermoplastic and even highly crosslinked duroplastic structures and networks. On the basis of the thermal reversib- ity, new materials with highly tunable properties can now be prepared, - ing able to change their mechanical and optoelectronic properties with very smallchangesofexternalstimuli. Thusthe?eldofhydrogen-bondedpolymers forms the basis for stimuli responsive and adaptable materials of the future.

Bacteria occupy a unique position in the living world. They are amongst the first inhabitants of planet earth, and have survived until the present day. Adaptation, adjustment, and accommodation are the hallmarks of their strategy for survival. Their structural simplicity, and yet independent lifestyle, has provided a baseline model system on which every branch of modern biology have been founded. This includes the fields of molecular genetics and recombinant DNA technology. Bacteria have been at the heart of developments in the field of biotechnology where today many microbial and eukaryotic (including human) metabolites have found industrial applications. Amenable to all modern tools and techniques, bacteriology has developed an interface with all other branches of biology, often providing the major leads and clues. In the present era of genomics, now that many microbial genomes have been sequenced, bacteria are destined to provide new information that will further our understanding of life and biological processes.
This book contains exhaustive information on almost all aspects of bacteria. The book deals exclusively with bacteria and includes the entire gamut of bacteriology. It will be useful to graduate and post-graduate levels but also to established researchers. The book is organized in such a way that it will give the reader an overview of our current understanding of bacteria. It will explain the categories under which various types have been grouped and describe the versatile range of metabolic processes which can be found in these microbial organisms. Their metabolic regulation, capacity to change and keep evolving and their pivotal role in natural processes arehighlighted. Research on bacteria, especially genetic engineering, will have far reaching applications in the future.

The volumes of this classic series, now referred to simply as "Zechmeister" after its founder, L. Zechmeister, have appeared under the Springer Imprint ever since the series' inauguration in 1938. The volumes contain contributions on various topics related to the origin, distribution, chemistry, synthesis, biochemistry, function or use of various classes of naturally occurring substances ranging from small molecules to biopolymers. Each contribution is written by a recognized authority in his field and provides a comprehensive and up-to-date review of the topic in question. Addressed to biologists, technologists, and chemists alike, the series can be used by the expert as a source of information and literature citations and by the non-expert as a means of orientation in a rapidly developing discipline.

The genesis of the volume, Plant Biotechnology and Molecular Markers, has been the occasion of the retirement of Professor Sant Saran Bhojwani from the Department of Botany, University of Delhi. For Professor Bhojwani, retirement only means relinquishing the chair as being a researcher and a teacher which has always been a way of life to him. Professor Bhojwani has been an ardent practitioner of modern plant biology and areas like Plant Biotechnology and Molecular Breeding have been close to his heart. The book contains original as well as review articles contributed by his admirers and associates who are experts in their area of research. While planning this contributory book our endeavour has been to incorporate articles that cover the entire gamut of Plant Biotechnology, and also applications of Molecular Markers. Besides articles on in vitro fertilization and micropropagation, there are articles on forest tree improvement through genetic engineering. Considering the importance of conservation of our precious natural wealth, one article deals with cryopreservation of plant material. Chapter on molecular marker considers DNA indexing as markers of clonal fidelity of in vitro regenerated plants and prevention against bio-piracy. A couple of write-ups also cover stage-specific gene markers, DNA polymorphism and genetic engineering, including raising of stress tolerant plants to sustain productivity and help in reclamation of degraded land.

The volumes of this classic series, now referred to simply as "Zechmeister" after its founder, L. Zechmeister, have appeared under the Springer Imprint ever since the series' inauguration in 1938. The volumes contain contributions on various topics related to the origin, distribution, chemistry, synthesis, biochemistry, function or use of various classes of naturally occurring substances ranging from small molecules to biopolymers. Each contribution is written by a recognized authority in his field and provides a comprehensive and up-to-date review of the topic in question. Addressed to biologists, technologists, and chemists alike, the series can be used by the expert as a source of information and literature citations and by the non-expert as a means of orientation in a rapidly developing discipline.

The discipline of microbiology that deals with an amazingly diverse group of simple organisms, such as viruses, archaea, bacteria, algae, fungi, and protozoa, is an exciting field of Science. Starting as a purely descriptive field, it has transformed into a truly experimental and interdisciplinary science inspiring a number of investigators to generate th a wealth of information on the entire gamut of microbiology. The later part of 20 century has been a golden era with molecular information coming in to unravel interesting insights ofthe microbial world. Ever since they were brought to light through a pair of ground glasses by the Dutchman, Antony van Leeuwenhoek, in later half of 17th century, they have been studied most extensively throughout the next three centuries, and are still revealing new facets of life and its functions. The interest in them, therefore, continues even in the 21 st century. Though they are simple, they provide a wealth of information on cell biology, physiology, biochemistry, ecology, and genetics and biotechnology. They, thus, constitute a model system to study a whole variety of subjects. All this provided the necessary impetus to write several valuable books on the subject of microbiology. While teaching a course of Microbial Genetics for the last 35 years at Delhi University, we strongly felt the need for authentic compiled data that could give exhaustive background information on each of the member groups that constitute the microbial world.

Any method of fitting equations to data may be called regression. Such equations are valuable for at least two purposes: making predictions and judging the strength of relationships. Because they provide a way of em pirically identifying how a variable is affected by other variables, regression methods have become essential in a wide range of fields, including the soeial seiences, engineering, medical research and business. Of the various methods of performing regression, least squares is the most widely used. In fact, linear least squares regression is by far the most widely used of any statistical technique. Although nonlinear least squares is covered in an appendix, this book is mainly ab out linear least squares applied to fit a single equation (as opposed to a system of equations). The writing of this book started in 1982. Since then, various drafts have been used at the University of Toronto for teaching a semester-Iong course to juniors, seniors and graduate students in a number of fields, including statistics, pharmacology, pharmacology, engineering, economics, forestry and the behav ioral seiences. Parts of the book have also been used in a quarter-Iong course given to Master's and Ph.D. students in public administration, urban plan ning and engineering at the University of Illinois at Chicago (UIC). This experience and the comments and critieisms from students helped forge the final version."