Contents

#### **Preface XI**


Preface

Circadian clocks are endogenous and temperature-compensating timekeepers that provide temporal organization of biological processes in living organisms including cyanobacteria, plants, animals and humans. Circadian rhythms allow living organisms to adapt to the daily light cycles associated with Earth's rotation and to anticipate and prepare for precise and regular environmental changes. The endogenous circadian rhythms are adjusted to the envi‐ ronment by different surrounding cues, such as temperature, light and redox cycles. Biologi‐ cal clocks regulate several biological functions, including hormone levels, body temperature,

This book discusses the fundamental advances of how the circadian clock regulates critical biological functions as well as the cellular and molecular mechanisms controlling circadian rhythm in living organisms. It also provides new insights into and sheds new light on the current research trends and future research directions related to circadian rhythm. This book provokes interest in many readers, researchers and scientists, who can find this infor‐ mation useful for the advancement of their research works towards a better understanding

The book includes eight chapters. The first introductory chapter "Circadian Rhythms and Their Molecular Mechanisms" presents an introduction to the history, importance and mo‐ lecular mechanisms of circadian rhythms in living organisms. The second chapter "Circadi‐ an Rhythm and Chronobiology" discusses the recent progresses related to circadian biological research as well as understanding how biological clocks govern the human me‐ tabolism. The third chapter "Circadian Clock Gene Expression and Drug/Toxicant Interac‐ tions as Novel Targets of Chronopharmacology and Chronotoxicology" discusses the interactions of circadian clock genes with drugs and/or toxicants to better understand the importance of circadian clock gene expression as novel targets in pharmacology and toxicol‐ ogy. The fourth chapter "Quantification of Irregular Rhythms in Chronobiology: A Time Series Perspective" compares wavelets and SSA analysis for the quantification of irregular rhythms at different frequency scales and discusses their respective advantages and disad‐ vantages for application in chronobiology. The fifth chapter "Jet Lag" describes the phenom‐ enon of jet lag and its associated symptoms. The sixth chapter "Features of Circadian Rhythms in Patients with Cerebrovascular Diseases" describes in detail the pathogenetic role of desynchronosis in the development of cerebrovascular diseases (CVD). The seventh chapter "The Chronobiology of Acid-Base Balance under General Anaesthesia in Rat Mod‐ el" reviews the status of acid-base balance and ion concentration in arterial blood under commonly used anaesthesias in experiments in dependence on the light-dark cycle in breathing rats. The eighth chapter "Sudden Death of Circadian Rhythm in Chagasic Patients

cell regeneration, metabolism, photoperiodism and other biological activities.

of circadian rhythm regulatory mechanisms.
