All galaxies host a super-massive black hole in their center. These black holes grow their mass in symbiosis with their host galaxy and moderate their star formation. When matter is driven towards the nucleus, an accretion disk is formed to transfer angular momentum and considerable energy is released when the material falls into the black hole: this is the phenomenon of active galactic nuclei (AGN). A nucleus can shine one thousand times more brightly than the entire galaxy with its 200 billion stars. The nuclear activity can take many forms, from very powerful quasars to more ordinary Seyfert galaxies, passing by radio-galaxies, which eject a collimated plasma at ten times the radius of the galaxy.This book examines all of these manifestations and presents a unified view. When two galaxies merge, a binary black hole is formed and the two black holes will spiral inwards and merge, emitting long gravitational waves, which could be detected by the future LISA satellite.

The fourth edition of this bestselling text will again provide the latest coverage of the biochemistry and physiology of vitamins and vitamin-like substances. Extensively revised and expanded on the basis of recent research findings with enlarged coverage of health effects of vitamin-like factors, it is ideally suited for students and an important reference for anyone interested in nutrition, food science, animal science or endocrinology. It contains a cohesive and well-organized presentation of each of the vitamins, as well as the history of their discoveries and current information about their roles in nutrition and health.

The Vitamins: Fundamental Aspects in Nutrition and Health, Sixth Edition presents both overviews and in-depth discussions of the sources, chemistry, metabolism and functions of these essential nutrients in physiology and health. Sections cover perspectives (history of discovery, general properties and impacts), individual Vitamins (their respective chemistries, metabolism), and their dietary sources and global needs. In addition, the inclusion and interpretation of recent clinical research findings relevant to all vitamins, particularly vitamins A, D, E, K, C, thiamin, folate and vitamin B12 is included, along with an expanded discussion on single-carbon metabolism), implications to neuropathies, and more.

Galaxies are vast ensembles of stars, gas and dust, embedded in dark matter halos. They are the basic building blocks of the Universe, gathered in groups, clusters and super-clusters. They exist in many forms, either as spheroids or disks. Classifications, such as the Hubble sequence (based on mass concentration and gas fraction) and the colormagnitude diagram (which separates a blue cloud from a red sequence) help to understand their formation and evolution. Galaxies spend a large part of their lives in the blue cloud, forming stars as spiral or dwarf galaxies. Then, via a mechanism that is still unclear, they stop forming stars and quietly end in the red sequence, as spheroids. This transformation may be due to galaxy interactions, or because of the feedback of active nuclei, through the energy released by their central super-massive black holes. These mechanisms could explain the history of cosmic star formation, the rate of which was far greater in the first half of the Universe s life. Galaxies delves into all of these surrounding subjects in six chapters written by dedicated, specialist astronomers and researchers in the field, from their numerical simulations to their evolutions.

Papers of the Paris meeting in June 1990 on Local Group Galaxies, molecules in early-type galaxies, observations of spiral structure in molecular clouds, a comparison with other gaseous components and IR emission, interacting galaxies and starbursts, gas and star dynamics, galaxy evolution, IRAS ult

In the post WWII era of the Cold War America and the free world battled to contain Communism within the boundaries of the USSR and communist China. The CIA waged one front of this war.

The Vitamins: Fundamental Aspects in Nutrition and Health, Fifth Edition, provides the latest coverage of the biochemistry and physiology of vitamins and vitamin-like substances. Health-related themes present insights into the use of vitamins, not only for general nutritional balance, but also as a factor in the prevention and/or treatment of specific health issues, such as overall immunity, inflammatory diseases, obesity, and anemia. Readers will gain an understanding of the roles vitamins play in gene expression and epigenetics, providing important information on the further development of personalized medical treatments that will also allow them to establish appropriate dietary programs based on individual genetic profiles. This cohesive, well-organized presentation of each vitamin includes key words, case studies, and coverage of the metabolic functions of appropriate vitamins. The readability of this complex content is highly regarded by students, instructors, researchers, and professionals alike.

Proceedings of the 146th Symposium of the International Astronomical Union, held in Paris, France, June 4-9, 1990

Are you living your life with purpose and meaning? Hope for the Human Spirit provides the secrets that will reach the depths of your soul and keep you on the path that is filled with Hope. Through these pages you will find unique topics that include how to find harmony with others, as well as how to divide your life into obtainable steps that can help you to find deeper relationships and higher productivity. Loaded with inspirational quotes from World Record setting pilot and composer Michael F Combs that are written to offer you daily peace and will boost your outlook on life. What is the difference between Prosperity and Profitability? How can you determine the method of Grounding that fits you the best? How can the way that you walk impact your relationship with others? The answers to these questions and many others are addressed in an easy to understand format. Carry this book with you and open it up to any page to find inspiration and hope.

In the post WWII era of the Cold War America and the free world battled to contain Communism within the boundaries of the USSR and communist China. The CIA waged one front of this war.