Popular science at its most exciting: the breaking new world of chronobiology - understanding the rhythm of life in humans and all plants and animals. The entire natural world is full of rhythms. The early bird catches the worm -and migrates to an internal calendar. Dormice hibernate away the winter. Plants open and close their flowers at the same hour each day. Bees search out nectar-rich flowers day after day. There are cicadas that can breed for only two weeks every 17 years. And in humans: why are people who work anti-social shifts more illness prone and die younger? What is jet-lag and can anything help? Why do teenagers refuse to get up in the morning, and are the rest of us really 'larks' or 'owls'? Why are most people born (and die) between 3am-5am? And should patients be given medicines (and operations) at set times of day, because the body reacts so differently in the morning, evening and at night? The answers lie in our biological clocks the mechanisms which give order to all living things. They impose a structure that enables us to change our behaviour in relation to the time of day, month or year. They are reset at sunrise and sunset each day to link astronomical time with an organism's internal time.

Interest in biological rhythms has been traced back more than 2,500]ears to Archilochus, the Greek poet, who in one of his fragments suggests ",,(i,,(VWO'KE o'olos pv{}J.tos txv{}pW7rOVS ~XH" (recognize what rhythm governs man) (Aschoff, 1974). Reference can also be made to the French student of medicine J. J. Virey who, in his thesis of 1814, used for the first time the expression "horloge vivante" (living clock) to describe daily rhythms and to D. C. W. Hufeland (1779) who called the 24-hour period the unit of our natural chronology. However, it was not until the 1930s that real progress was made in the analysis of biological rhythms; and Erwin Bunning was encouraged to publish the first, and still not outdated, monograph in the field in 1958. Two years later, in the middle of exciting discoveries, we took a breather at the Cold Spring Harbor Symposium on Biological Clocks. Its survey on rules considered valid at that time, and Pittendrigh's anticipating view on the temporal organization of living systems, made it a milestone on our way from a more formalistic description of biological rhythms to the understanding of their structural and physiological basis.

Introducing Biological Rhythms is a primer that serves to introduce individuals to the area of biological rhythms. It describes the major characteristics and discusses the implications and applications of these rhythms, while citing scientific results and references. Also, the primer includes essays that provide in-depth historic and other background information for those interested in more specific topics or concepts. It covers a basic cross-section of the field of chronobiology clearly enough so that it can be understood by a novice, or an undergraduate student, but that it would also be sufficiently technical and detailed for the scientist.

An introduction to the mathematical, computational, and analytical techniques used for modeling biological rhythms, presenting tools from many disciplines and example applications. All areas of biology and medicine contain rhythms, and these behaviors are best understood through mathematical tools and techniques. This book offers a survey of mathematical, computational, and analytical techniques used for modeling biological rhythms, gathering these methods for the first time in one volume. Drawing on material from such disciplines as mathematical biology, nonlinear dynamics, physics, statistics, and engineering, it presents practical advice and techniques for studying biological rhythms, with a common language. The chapters proceed with increasing mathematical abstraction. Part I, on models, highlights the implicit assumptions and common pitfalls of modeling, and is accessible to readers with basic knowledge of differential equations and linear algebra. Part II, on behaviors, focuses on simpler models, describing common properties of biological rhythms that range from the firing properties of squid giant axon to human circadian rhythms. Part III, on mathematical techniques, guides readers who have specific models or goals in mind. Sections on “frontiers” present the latest research; “theory” sections present interesting mathematical results using more accessible approaches than can be found elsewhere. Each chapter offers exercises. Commented MATLAB code is provided to help readers get practical experience. The book, by an expert in the field, can be used as a textbook for undergraduate courses in mathematical biology or graduate courses in modeling biological rhythms and as a reference for researchers.

The natural world is full of rhythms. How do birds know when to return to their nesting grounds? What effect do the seasons have on our wellbeing, and how does the season in which we are born affect our subsequent life chances? How did humans get the idea that there were seasons 50,000 years ago? Seasons of Life explains why the seasons occur, the impact of seasonal change and how organisms have evolved to anticipate these changes. For although we mask the effects of seasonal changes by warming our homes, lighting our nights, preserving foods and storing water, we cannot hide from them.

(Chapters 11 to 14) summarise important features of the biological clock at the level of whole animal covering all vertebrate classes (fish to mammal). Chapters 15 and 16 are on long term (seasonal) rhythms in plants and higher vertebrates. Short term rhythms (ultradian rhythms), the significance of having a clock system in animals living in extreme (arctic) environments, and the diversity of circadian responses to melatonin, the key endocrine element involved in regulation of biological rhythms, have been discussed in Chapters 17 to 19. Finally, a chapter on sensitivity to light of the photoperiodic clock is added which, using vertebrate examples, illustrates the importance of wavelength and intensity of light on circadian and non-circadian functions. A well-known expert writes each chapter. When presenting information, the text provides consistent thematic coverage and feeling for the methods of investigation. Reference citation within the body of the text adequately reflects the literature as subject is developed. A chapter begins with an abstract that enables a reader to know at the first glance the important points covered in that chapter. The chapter concludes with a full citation of references included in the text, which could be useful for further reading. The book ends with a comprehensive subject index that may be useful for quick searches.

Like food and water, sleep is essential for all. In this excellent study aid, the author looks at the nature and purpose of sleeping andrelated disorders, dreamingand hypnosis. This clear and focused introductionprovides a fantasticentry point for studentsseeking a deeper understanding of altered states of awareness.