Download or read book Intrinsic Clocks written by Timo Partonen and published by Frontiers Media SA. This book was released on 2018-03-19 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Intrinsic Clocks" presents an array of current research activities on intrinsic clocks and their contributions to biology and physiology. It elucidates the current models for the intrinsic clocks, their molecular components and key mechanisms as well as the key brain regions and animal models for their behavioral analysis. It provides a timely view on how these clocks guide behavior, and how their disruption may cause depressive-like behavior and impairment in cognitive functions. Thereby, any specific method by which the mood-related functions of the intrinsic clocks might be influenced bears therapeutic potential and has clinical interest. The importance of some of these mechanisms was highlighted by the 2017 award of the Nobel Prize in Physiology or Medicine to Jeffrey C. Hall, Michael Rosbash, and Michael W. Young for their discoveries of the genetic control of the daily biological rhythm. The key to the explanation was the discovery of transcription-translation feedback loops of the so-called “clock genes.”
Download or read book Intrinsic Clocks written by and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Intrinsic Clocks" presents an array of current research activities on intrinsic clocks and their contributions to biology and physiology. It elucidates the current models for the intrinsic clocks, their molecular components and key mechanisms as well as the key brain regions and animal models for their behavioral analysis. It provides a timely view on how these clocks guide behavior, and how their disruption may cause depressive-like behavior and impairment in cognitive functions. Thereby, any specific method by which the mood-related functions of the intrinsic clocks might be influenced bears therapeutic potential and has clinical interest. The importance of some of these mechanisms was highlighted by the 2017 award of the Nobel Prize in Physiology or Medicine to Jeffrey C. Hall, Michael Rosbash, and Michael W. Young for their discoveries of the genetic control of the daily biological rhythm. The key to the explanation was the discovery of transcription-translation feedback loops of the so-called "clock genes."
Download or read book Circadian Clocks written by Achim Kramer and published by Springer Science & Business Media. This book was released on 2013-04-18 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides the reader with a contemporary and comprehensive overview about the molecular, cellular and system-wide principles of circadian clock regulation. Emphasis is placed on the importance of circadian clocks for the timing of therapeutic interventions.
Download or read book Remodeling of cardiac passive electrical properties and susceptibility to ventricular and atrial arrhythmias written by George E. Billman and published by Frontiers Media SA. This book was released on 2015-09-25 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effective management of cardiac arrhythmias, either of atrial or of ventricular origin, remains a major challenge. Sudden cardiac death due to ventricular tachyarrhythmias remains the leading cause of death in industrialized countries while atrial fibrillation is the most common rhythm disorder; an arrhythmia that’s prevalence is increasing and accounts for nearly one quarter of ischemic stokes the elderly population. Yet, despite the enormity of the problem, effective therapeutic interventions remain elusive. In fact, several initially promising antiarrhythmic agents were found to increase rather than decrease mortality in patients recovering from myocardial infarction. The question then is what went wrong, why have these interventions proven to be so ineffective? An obvious answer is the drugs were designed to attack the wrong therapeutic target. Clearly, targeting single ion channels (using either isolated ion channels or single myocytes preparations) has proven to be less than effective. What then is the appropriate target? It is well established that cardiac electrical properties can vary substantially between single cells and intact preparations. One obvious example is the observation that action potential duration is much longer in isolated cells as compared to multi-cellular preparations or intact hearts. Due to the low electrical resistance between adjacent myocytes, the cells act in coordinated fashion producing “electrotonic interdependence” between neighboring cells. Myocardial infarction and/or acute ischemia provoke profound changes in the passive electrical properties of cardiac muscle. In particular, electrotonic uncoupling of the myocytes disrupts the coordinated activation and repolarization of cardiac tissue. The resulting compensatory changes in ionic currents decrease cardiac electrical stability increasing the risk for life-threatening changes in the cardiac rhythm. Thus, the electrical properties of myocardial cells must be considered as a unit rather than in isolation. It is the purpose of this Research Topic to evaluate the largely neglected relationship between changes in passive electrical properties of cardiac muscle and arrhythmia formation.
Download or read book Insect Clocks written by D. S. Saunders and published by Elsevier. This book was released on 2014-05-19 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: Insect Clocks is mainly concerned with the phenomena in which ""environmental time"" has a practical implication for the life of insects for them to perform behavioral or physiological episodes at the ""right time"" and season. This text first discusses the concept of rhythms and clocks, along with the seasonal changes in the environment that affect a particular group of organisms. This book then explains circadian rhythms of insects. Photoperiodism and seasonal cycles of development; photoperiodic response, clock, and counter; and other types of insect clock are also tackled. This text concludes by explaining the anatomical location of photoreceptors and clocks. This publication will be invaluable to those interested in studying insects and their development affected by circles of influences.
Download or read book Endocrinology written by S.S. Nussey and published by CRC Press. This book was released on 2001-06-15 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt: Traditionally, endocrinology textbooks have been either short notes or multi-author, multi-volume monster, all of which present clinical material last and often only briefly. Endocrinology is different and used real cases to lead readers into the text and then describes the biochemistry, physiology, and anatomy they need to understand the case. The
Download or read book Human Circadian Physiology written by Charles A. Czeisler and published by . This book was released on 1978 with total page 692 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book VCSELs for Cesium Based Miniaturized Atomic Clocks written by Ahmed Al-Samaneh and published by BoD – Books on Demand. This book was released on 2015-09-23 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: Frequency standards or clocks provide time references for a wide range of applications such as synchronization of communication networks, remote sensing and global positioning. Over the last couple of decades, demands on the data rates of many communication systems have substantially increased, imposing more restricted requirements on the stability of their timing devices. At the same time applications have become more mobile, increasing the demand for small and low-power clocks. Atomic clocks have provided the most stable frequency references for more than 50 years. However, the size and power requirements of microwave-cavity-based atomic clocks prohibit them from being portable and battery-operated. Hence, research on miniaturized atomic clocks (MACs) has been initiated by various research groups. A European research project on MACs, funded by the European commission started in 2008. This dissertation reports on the achievements within the European research project in the development of suitable lasers for such atomic clocks. Vertical-cavity surface-emitting lasers (VCSELs) are compelling light sources for MACs because of their low power consumption, high modulation bandwidth, and favorable beam characteristics. VCSELs must feature polarization-stable single-mode emission. Additionally, they must provide narrow linewidth emission at a center wavelength of about 894.6nm and be well suited for harmonic modulation at about 4.6GHz in order to employ coherent population trapping effect at the cesium D1 line. The polarization orientation of the emitted light of a standard VCSEL is a priori unknown. Polarization control is achieved by etching a shallow surface grating in the top Bragg mirror. For the purpose of integration with the clock microsystem, flip-chip-bondable VCSEL designs are realized. Such designs facilitate a straightforward mounting and make the electrical contacts high-frequency compatible.
Download or read book Sleep and Clocks in Aging and Longevity written by Anita Jagota and published by Springer Nature. This book was released on 2023-03-06 with total page 553 pages. Available in PDF, EPUB and Kindle. Book excerpt: This edited volume focuses on the interplay between sleep and circadian rhythms with health, aging and longevity. Sleep is absolutely important for human health and survival, as insufficient sleep is associated with a plethora of conditions, including the poor quality of life, onset of several diseases, and premature death. The sleep–wake cycle is an evolutionary conserved neurobiological phenomenon, and is a prominent manifestation of the biological clocks localised in the suprachiasmatic nucleus (SCN). Understanding bidirectional relationship between sleep and circadian rhythms is of utmost importance and urgency, especially in the context of modern lifestyle where sleep is often out of phase with the internal body clocks, social jetlag, artificial lights and so on. The 25 chapters by leading researchers and experts from 11 countries are arranged into seven sections: understanding sleep and clock interlink in health and longevity; sleep, aging and longevity; clock, aging and longevity; melatonin, sleep and clock; genetic regulation of sleep and clock; therapeutic interventions in sleep disorders and clock misalignment; and experimental models to study sleep and clocks in aging and longevity. This book is useful for advanced undergraduate and graduate students, and researchers, educators, and other biomedical professionals.
Download or read book Biological Clocks Rhythms and Oscillations written by Daniel B. Forger and published by MIT Press. This book was released on 2017-11-16 with total page 369 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Aspects of Pacemakers written by Oliver Vonend and published by BoD – Books on Demand. This book was released on 2011-09-15 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: Outstanding steps forward were made in the last decades in terms of identification of endogenous pacemakers and the exploration of their controllability. New "artifical" devices were developed and are now able to do much more than solely pacemaking of the heart. In this book different aspects of pacemaker - functions and interactions, in various organ systems were examined. In addition, various areas of application and the potential side effects and complications of the devices were discussed.
Download or read book The End of the Timeless God written by R. T. Mullins and published by Oxford University Press. This book was released on 2016-01-07 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: The claim that God is timeless has been the majority view throughout church history. However, it is not obvious that divine timelessness is compatible with fundamental Christian doctrines such as creation and incarnation. Theologians have long been aware of the conflict between divine timelessness and Christian doctrine, and various solutions to these conflicts have been developed. In contemporary thought, it is widely agreed that new theories on the nature of time can further help solve these conflicts. Do these solutions actually solve the conflict? Can the Christian God be timeless? The End of the Timeless God sets forth a thorough investigation into the Christian understanding of God and the God-world relationship. It argues that the Christian God cannot be timeless.
Download or read book Circadian Clocks and Their Adjustment written by Derek J. Chadwick and published by John Wiley & Sons. This book was released on 2008-04-30 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: Prestigious contributors describe the genetic, molecular, anatomical and neurochemical mechanisms and pathways that operate to regulate and control circadian rhythmicity and functioning in organisms ranging from unicellular algae to human beings. Also considers the implications of the basic and clinical research for humans.
Download or read book Therapeutic Implications of Circadian Rhythms written by Guangrui Yang and published by Frontiers Media SA. This book was released on 2015-10-12 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: Circadian rhythms are biological processes displaying endogenous and entrainable oscillations of about 24 hours. They are driven by a group of genes called clock genes that have been widely observed in plants, animals and even in bacteria. In mammals, the core clock genes are rhythmically expressed in both the suprachiasmatic nucleus (SCN), the master clock residing in the hypothalamus, and almost all peripheral tissues where they control numerous target genes in a circadian manner, and thus affect many physiological and biochemical processes. Evidence suggests that disruption of the circadian rhythms (or desynchronization) is a significant risk factor for the development of metabolic diseases, cardiovascular diseases, cancer and sleep disorders. Evidence also suggests that the disruption suppresses immune function and increases vulnerability to infectious diseases. Restoring or strengthening the circadian rhythm may be therapeutic for these conditions. This becomes exceptionally important in modern societies because many people are suffering from frequent desynchronization due to shift working, exposure to artificial light, travel by transmeridian air flight, and involvement in social activities. Besides, the temporal variations in the incidence and severity of many diseases, such as the onset of cardiovascular events, chronic obstructive pulmonary disease (COPD), inflammatory diseases and mental disorders have also drawn increasing attention to the circadian clock. The circadian rhythms affect not only the health status, but also the drug efficiency. The effects (and side effects) of many drugs vary with biological timing. The tolerance of many medications displays circadian variation as well. The timing of medical treatment in coordination with the body clock may significantly increase the desired effects of drugs, and lower the dose and toxicity. In addition, circadian rhythms can also be modulated by some therapeutic drugs, for example, melatonin and modafinil, which are used to treat circadian rhythm sleep disorders. In this Research Topic, we assemble a series of critical review and research articles that focus on the therapeutic implications of circadian rhythms. Topics include, but are not limited to: • Circadian disruption caused diseases or disorders and related intervention • Temporal manifestation of diseases or disorders and therapeutic implications • The effects of circadian rhythms on drugs • The effects of drugs on circadian rhythms
Download or read book Factors Influencing Mammalian Kidney Development Implications for Health in Adult Life written by Karen Moritz and published by Springer Science & Business Media. This book was released on 2008-05-11 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this monograph the authors have emphasized a number of important concepts in mammalian kidney development. Emphasis has been put on methodology so that the reader can understand how certain results or conclusions were reached and what the optimal methods for reliable results to be obtained are. In addition, as well as descriptions of the morphology there is information on the genetic basis of the structural development. In addition much attention has been paid to how nephron number may be altered by changes in the environment of the developing kidney and to the consequences for the remaining nephron gene expression and kidney function when total nephron number is altered. The consequences for the health of the adult, upon the formation of an adult kidney with altered nephron number and (potentially) gene expression, can be quite serious. The epigenetic mechanisms by which such changes can occur are introduced as a very fertile field for future investigation.
Download or read book The Circadian Clock written by Urs Albrecht and published by Springer Science & Business Media. This book was released on 2010-01-23 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the invitation to edit this volume, I wanted to take the opportunity to assemble reviews on different aspects of circadian clocks and rhythms. Although most c- tributions in this volume focus on mammalian circadian clocks, the historical int- duction and comparative clocks section illustrate the importance of various other organisms in deciphering the mechanisms and principles of circadian biology. Circadian rhythms have been studied for centuries, but only recently, a mole- lar understanding of this process has emerged. This has taken research on circadian clocks from mystic phenomenology to a mechanistic level; chains of molecular events can describe phenomena with remarkable accuracy. Nevertheless, current models of the functioning of circadian clocks are still rudimentary. This is not due to the faultiness of discovered mechanisms, but due to the lack of undiscovered processes involved in contributing to circadian rhythmicity. We know for example, that the general circadian mechanism is not regulated equally in all tissues of m- mals. Hence, a lot still needs to be discovered to get a full understanding of cir- dian rhythms at the systems level. In this respect, technology has advanced at high speed in the last years and provided us with data illustrating the sheer complexity of regulation of physiological processes in organisms. To handle this information, computer aided integration of the results is of utmost importance in order to d- cover novel concepts that ultimately need to be tested experimentally.
Download or read book Relativity written by Steve Adams and published by CRC Press. This book was released on 2017-06-30 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides the essential principles and results of special relativity as required by undergraduates. The text uses a geometric interpretation of space-time so that a general theory is seen as a natural extension of the special theory. Although most results are derived from first principles, complex and distracting mathematics is avoided and all mathe
