الصفحة 2
الصفحة 2
Vitiligo
Vitiligo is an acquired pigmentary skin disorder caused by the absence of pigmentary cells from the epidermis that results in white macules and patches on the body. Initial lesions occur most frequently on the hands, forearms, feet, and face, favoring a periocular or perioral distribution. The course of the disease is often unpredictable and varies in response to the treatment. Depigmentation often the cause of psychological distress, social stigmatization, and low self-esteem...
Vitamin deficiency
Vitamin deficiency is the condition of a long-term lack of a vitamin. When caused by not enough vitamin intake it is classified as a primary deficiency, whereas when due to an underlying disorder such as malabsorption it is called a secondary deficiency. An underlying disorder may be metabolic – as in a genetic defect for converting tryptophan to niacin – or from lifestyle choices that increase vitamin needs, such as smoking or drinking alcohol. Governments guidelines on vitamin deficiencies advise certain intakes for healthy people, with specific values for women, men, babies, the elderly, and during pregnancy or breastfeeding. Many countries have mandated vitamin food fortification programs to prevent commonly occurring vitamin deficiencies. Conversely hypervitaminosis refers to symptoms caused by vitamin intakes in excess of needs, especially for fat-soluble vitamins that can accumulate in body tissues.
Vitamin D
There has been a growing interest in vitamin D during the last decades, which has boosted an increasing number of scientific papers on this topic. Vitamin D has a significant role in calcium homeostasis and metabolism, vitamin D deficiency is a worldwide health problem that affects not only musculoskeletal health but also a wide range of acute and chronic diseases, There is potentially a great upside to increasing the vitamin D status of children and adults worldwide for improving musculoskeletal health and reducing the risk of chronic illnesses, including some cancers, autoimmune diseases, infectious diseases, type 2 diabetes mellitus, neurocognitive disorders, and mortality. In addition, there are many evidences about the correlation between the vit.D and the levels of quality of life. Recently, taking of vit.D3 become in the guideline for cure and help the treatment of COVID-19 epidemic.
Visual Astronomy Under Dark Skies: A New Approach to Observing Deep Space
Modern astronomical telescopes, along with other advances in technology, have brought the deep sky – star clusters, nebulae and the galaxies – within visual reach of amateur astronomers. It isn’t necessary to image deep-sky objects in order to see them; you look at them in real-time by using modern observing techniques and enhancement technology. The first requirement is a truly dark observing site. Given a location with clear, dark night skies everything else follows… this book contains all you need to know about what to observe, how to get superb views of faint and distant astronomical objects, and how to use the best of today’s commercial equipment for visual observing.
Viral Genome Packaging: Genetics, Structure, and Mechanism
Viral Genome Packaging focuses on the process of genome "packaging" within a pre-formed viral procapsid. The chapters of this book concentrate on the biochemistry, enzymology and structural aspects of the genome packaging machinery. This book defines a broad mechanistic basis for the process across the prokaryotic and eukaryotic border, and for DNA and RNA viruses. The biochemical, biophysical and structural aspects of genome packaging are examined in detail.
Video Traces for Network Performance Evaluation : A Comprehensive Overview and Guide on Video Traces and Their Utilization in Networking Research
Multimedia networking applications and, in particular, the transport of compressed video are expected to contribute significantly to the trafic in the future Internet and wireless networks. For transport over networks, video is typically encoded (i. e. , compressed) to reduce the bandwidth requirements. Even compressed video, however, requires large bandwidths of the order of hundred kbps or Mbps. In addition, compressed video streams typically inhibit highly variable bit rates (VBR) as well as long range dependence (LRD) properties. This, in conjunction with the stringent Quality of Service (QoS) requirements (loss and delay) of video tra?c, makes the transport of video tra?cover communication networks a challenging problem. As a consequence, in the last decade the networking research community has witnessed an - plosion in research on all aspects of video transport.
Venezuela : A Petro-State Using Renewable Energies : A Contribution to the Global Debate about New Renewable Energies for Electricity Generation
In spite of the economic role of oil, Venezuela has started developing hydroelectricity since the 1950s. At present, the country is trying to introduce additional renewable energy sources (RES) but still has to overcome a series of hurdles in order to deploy them. Unlike other developing countries, oil countries such as Venezuela do not lack financial means and sometimes show a tendency to solve problems by using money when other approaches could be more helpful. The main goal of this qualitative, comparative policy analysis is to find out whether the availability of oil revenues restraints or favors the adoption of RES. Based on the rentier state theory, Germán Massabié examines the reasons why Petro states try to dispose of their natural wealth to take advantage of non-conventional energy sources. He analyses and interprets primary and secondary data collected in Germany and in Venezuela and draws on interviews with Venezuelan experts, policy makers, and key actors. The study allows a look beyond laws, development programs, and official statements.
Variations on Constants : Flow Analysis of Sequential and Parallel Programs
This monograph, a revised version of the author's habilitation thesis, focusses on optimal flow analysis of sequential and parallel programs. It studies algorithmic properties of various versions of the well-known constant-propagation problem. In order to come to grips with the variants considered, it combines techniques from different areas such as linear algebra, computable ring theory, abstract interpretation, program verification, complexity theory, etc. Combination of techniques is the key to further progress in automatic analysis and constant-propagation allows us to illustrate this point in a theoretical study.
Validity and reliability in built environment research : A selection of case studies
Presents case studies that emphasize reliability and validity in different examples of qualitative, quantitative and mixed method data sets, as well as covering action research and grounded theory. The reader is guided through case studies that demonstrate: An understanding of the reliability and validity approaches from social science and built environment perspectives in alignment with the relevant research philosophies, approaches and data collection strategies / Real research projects that have been conducted by expert researchers on topics such as Lean, BIM, Housing and Sustainability to answer specific or evolving questions in relation to the reliability and validity of research / A simple and easy method that students at Masters and PhD levels can relate to in order to adopt a sound reliability and validity approach to their research
Vacuum Technology : Practice for Scientific Instruments
Nanotechnology has reached a level where almost every new development and even every new product uses features of nanoscopic properties of materials. As a consequence, an enormous amount of scientific instruments is used in order to synthesize and analyze new structures and materials. Due to the surface sensitivity of such materials, many of these instruments require ultrahigh vacuum that has to be provided under extreme conditions like very high voltages. In this book, Yoshimura provides a review of the UHV related development during the last decades. His very broad experience in the design enables him to present us this detailed reference. After a general description how to design UHV systems, he covers all important issue in detail, like pumps, outgasing, Gauges, and Electrodes for high voltages.
Uveitis and Immunological Disorders
The purpose of this volume of "Essentials in Ophthalmology" is to provide the ophthalmologist with our present understanding of the pathogenesis of the most frequent immune-mediated disorders of the eye and a practical approach to these diseases. "Uveitis and Immunological Disorders / "Fills the gap between textbooks and original research publications / Focuses on clinical aspects of inflammatory eye diseases / Covers a broad spectrum, including diseases affecting the conjunctiva, sclera and cornea as well as intraocular inflammation / Includes basic research aspects such as immune mechanisms and genetics / Is quick and easy to read: highly structured with "core messages" and "summaries" for the clinician
Uveitis and Immunological Disorders
Summaries of clinically relevant information fer of new information in vision science and have been provided throughout each chapter. evidence-based medicine into clinical practice. Each subspecialty area now has been covered We thought that this prospicient idea would be once, and the response to the frst eight volumes moved and guided by a resolute commitment in the series has been enthusiastically positive. to excellence. It is reasonable to now update our With the start of the second cycle of subspecialty readers with what has been achieved. coverage, the dissemination of practical informa- Te immediate goal was to transfer informa- tion will be continued as we learn more about tion through a high quality quarterly publication the emerging advances in various ophthalmic in which ophthalmology would be represented by subspecialties that can be applied to obtain the eight subspecialties.
Utility Maximization, Choice and Preference
The utility maximization paradigm forms the basis of many economic, psychological, cognitive and behavioral models. Since it was first devised in the eighteenth century, numerous examples have revealed the deficiencies of the concept. This book makes a contribution to overcome those deficiencies by taking into account insensitivity of measurement threshold and context of choice. It covers classic theory as a special, context-free case and gives a systematic overview of new models of utility maximization within a context-dependent threshold as well as related preference and choice models. The second edition has been updated to include the most recent developments and a new chapter on classic and new results for infinite sets.
Urinary Stone Disease : The Practical Guide to Medical and Surgical Management
Urinary stone disease has afflicted mankind for centuries and continues to be a significant medical ailment throughout the world. Contemporary management reflects the changes and evolution that have occurred in both medicine and, specifically, urology. Traditional open surgery has been nearly replaced by minimally invasive techniques, the result of technologic innovations, miniaturization of instruments, and interdisciplinary collaboration. Nevertheless, nephrolithiasis remains a chronic disease and our fundamental understanding of the pathogenesis, and molecular and genetic basis of stones as well as their prevention, remains rudimentary. In addition, interest in disease prevention continues to grow and understanding basic questions and the underlying pathophysiology of stone disease will help optimize management strategies. Future advances in urinary stone disease will be the result of collaboration among urologists, nephrologists, radiologists, dieticians, scientists, and partners in industry. Physicians must not be complacent with the current status quo or be overly eager to intervene because techniques are less invasive; rather, the goals should be a better understanding of the underlying disease process in order to identify those at risk, prophylax against stone development and recurrence, and improved nonsurgical therapies.
Universal Artificial Intelligence : Sequential Decisions Based on Algorithmic Probability
This book presents sequential decision theory from a novel algorithmic information theory perspective. While the former is suited for active agents in known environments, the latter is suited for passive prediction in unknown environments. The book introduces these two well-known but very different ideas and removes the limitations by unifying them to one parameter-free theory of an optimal reinforcement learning agent embedded in an arbitrary unknown environment. Most if not all AI problems can easily be formulated within this theory, which reduces the conceptual problems to pure computational ones. Considered problem classes include sequence prediction, strategic games, function minimization, reinforcement and supervised learning. The discussion includes formal definitions of intelligence order relations, the horizon problem and relations to other approaches to AI.
United Nations Peace Operations in a Changing Global Order
This volume explores how UN peace operations are adapting to four trends in the changing global order: the rebalancing of relations between states of the global North and the global South; the rise of regional organisations as providers of peace; the rise of violent extremism and fundamentalist non-state actors; and increasing demands from non-state actors for greater emphasis on human security. It identifies emerging conflict and peace trends (robustness of responses, rise of non-state threats, cross-state conflicts) and puts them in the context of tectonic shifts in the global order (rise of emerging powers, North–South rebalancing, emergence of regional organisations as providers of peace). The volume stimulates a discussion between practitioners and academics, offering an analysis of how the international community collectively makes sense of the changing global order and its implications for UN peace operations.
Unitals in Projective Planes
This clearly written text is the first book on unitals embedded in finite projective planes. Unitals are key structures in square order projective planes, and have connections with other structures in algebra. They provide a link between groups and geometries. There is a considerable number of research articles concerning unitals, and there also exist many open problems. This book is a thorough survey of the research literature on embedded unitals which collects this material in book form for the first time.
Unfoldings : A Partial-Order Approach to Model Checking
In this book the authors introduce unfoldings, an approach to model checking which alleviates the state explosion problem by means of concurrency theory. They offer a gentle introduction to the basics of the method, and in particular they detail an unfolding-based algorithm for model checking concurrent systems against properties specified as formulas of linear temporal logic (LTL). Self-contained chapters cover transition systems and their products; unfolding products; search procedures for basic verification problems, such as reachability and livelocks; and model checking LTL.
Understanding Sleep and Dreaming
Although sleep has been the subject of serious study for several decades, there has not been available an integrated, introductory text for more than ten years. Understanding Sleep and Dreaming fills this need with complete coverage of all aspects of sleep, dreaming, and sleep disorders, and is comprehensible as well as comprehensive. In accessible language, this text reviews the basic physiological mechanisms of sleep and the intertwined psychological ramifications. Most important, it is up-to-date, containing the latest information on the influence of orexin/hypocretin, nocturnal eating syndrome, the local cell theory of sleep, the effects of sleep deprivation, and the advantages of delaying school start times for teenagers.
Understanding Programming Languages
This book is about describing the meaning of programming languages. While a compiler or an interpreter offers a form of formal description of a language, it is not something that can be used as a basis for reasoning about that language nor can it serve as a definition of a programming language itself since this must allow a range of implementations. By writing a formal semantics of a language a designer can yield a far shorter description and tease out, analyse and record design choices.Early in the book the author introduces a simple notation, a meta-language, used to record descriptions of the semantics of languages. In a practical approach, he considers dozens of issues that arise in current programming languages and the key techniques that must be mastered in order to write the required formal semantic descriptions. The book concludes with a discussion of the eight key challenges: delimiting a language (concrete representation), delimiting the abstract content of a language, recording semantics (deterministic languages), operational semantics (non-determinism), context dependency, modelling sharing, modelling concurrency, and modelling exits.
