Distribution by Scientific Domains

Kinds of Overview

  • brief overview
  • broad overview
  • clinical overview
  • complete overview
  • comprehensive overview
  • concise overview
  • critical overview
  • detailed overview
  • general overview
  • historical overview
  • introductory overview
  • personal overview
  • practical overview
  • short historical overview
  • short overview
  • systematic overview
  • up-to-date overview
  • updated overview

  • Selected Abstracts


    John Watson
    The species of Tropaeolum sect. Chilensia Sparre, are discussed. Their phytogeography, ecology, evolution and pollination are considered. Photographs of habitats, and of most of the species taken in the wild, are shown. A synopsis of all the species in the section, and a new arrangement of subsections is provided. [source]


    ABSTRACT. Proxy data are our only source of knowledge of temperature variability in the period prior to instrumental temperature measurements. Until recently, very few quantitative palaeotemperature records extended back a millennium or more, but the number is now increasing. Here, the first systematic survey is presented, with graphic representations, of most quantitative temperature proxy data records covering the last two millennia that have been published in the peer-reviewed literature. In total, 71 series are presented together with basic essential information on each record. This overview will hopefully assist future palaeoclimatic research by facilitating an orientation among available palaeotemperature records and thus reduce the risk of missing less well-known proxy series. The records show an amplitude between maximum and minimum temperatures during the past two millennia on centennial timescales ranging from c. 0.5 to 4°C and averaging c. 1.5,2°C for both high and low latitudes, although these variations are not always occurring synchronous. Both the Medieval Warm Period, the Little Ice Age and the 20th century warming are clearly visible in most records, whereas the Roman Warm Period and the Dark Age Cold Period are less clearly discernible. [source]

    Supercritical water for environmental technologies

    Dr Anne Loppinet-Serani
    Abstract OVERVIEW: Supercritical water is a great medium in which to perform chemical reactions and to develop processes. Due to its unique thermo-physico-chemical properties, supercritical water is able to play the role of solvent of organic compounds and/or to react with them. These specific properties have been used since the 1990s to develop new technologies dedicated to the environment and energy. IMPACT: Supercritical water based technologies are innovative and efficient processes having a strong impact on society, the environment and the economy, and is termed a sustainable technology. APPLICATIONS: Three main applications for supercritical water technology are under development: (i) supercritical water oxidation (SCWO); (ii) supercritical water biomass gasification (SCBG); and (iii) hydrolysis of polymers in supercritical water (HPSCW) for composites/plastics recycling. In this paper some fundamentals of supercritical water are first presented to introduce the above three major developments. Then these technologies are reviewed in terms of their present and future industrial development and their impact on the environment and on energy production. Copyright © 2010 Society of Chemical Industry [source]

    Liquid membrane technology: fundamentals and review of its applications

    M. F. San Román
    Abstract OVERVIEW: During the past two decades, liquid membrane technology has grown into an accepted unit operation for a wide variety of separations. The increase in the use of this technology owing to strict environmental regulations and legislation together with the wider acceptance of this technology in preference to conventional separation processes has led to a spectacular advance in membrane development, module configurations, applications, etc. IMPACT: Liquid membrane technology makes it possible to attain high selectivity as well as efficient use of energy and material relative to many other separation systems. However, in spite of the known advantages of liquid membranes, there are very few examples of industrial applications because of the problems associated with the stability of the liquid membrane. APPLICATIONS: Liquid membrane technology has found applications in the fields of chemical and pharmaceutical technology, biotechnology, food processing and environmental engineering. On the other hand, its use in other fields, such as in the case of hydrogen separation, the recovery of aroma compounds from fruits, the application of ionic liquids in the membrane formulation, etc., is increasing rapidly. Copyright © 2009 Society of Chemical Industry [source]

    Contributions of electrochemical oxidation to waste-water treatment: fundamentals and review of applications

    Ángela Anglada
    Abstract OVERVIEW: This paper provides an overview of some fundamental aspects of electrochemical oxidation and gives updated information on the application of this technology to waste-water treatment. In recent years, electrochemical oxidation has gained increasing interest due to its outstanding technical characteristics for eliminating a wide variety of pollutants normally present in waste-waters such as refractory organic matter, nitrogen species and microorganisms. IMPACT: The strict disposal limits and health quality standards set by legislation may be met by applying electrochemical oxidation. However, treatment costs have to be cut down before full-scale application of this technology. Deployment of electrochemical oxidation in combination with other technologies and the use of renewable sources to power this process are two steps in this direction. APPLICATIONS: Effluents from landfill and a wide diversity of industrial effluents including the agro-industry, chemical, textile, tannery and food industry, have been effectively treated by this technology. Its high efficiency together with its disinfection capabilities makes electro-oxidation a suitable technology for water reuse programs. Copyright © 2009 Society of Chemical Industry [source]


    Amélie Charles
    Abstract This paper reviews the recent developments in the field of the variance-ratio (VR) tests of the random walk and martingale hypothesis. In particular, we present the conventional individual and multiple VR tests as well as their improved modifications based on power-transformed statistics, rank and sign tests, subsampling and bootstrap methods, among others. We also re-examine the weak-form efficiency for five emerging equity markets in Latin America. [source]


    Julien Pénin
    Abstract This paper reviews current literature on open knowledge disclosure strategies used by firms. It is usually acknowledged that for an innovative firm that does not benefit from a natural protection (such as lead time advance) the best strategy is to keep an innovation secret as long as possible or to protect it through an exclusive patent. However, in apparent contrast to this traditional view, many studies suggest that firms often disclose important parts of their knowledge through scientific publications, conferences, the Internet, etc. This paper aims to provide an overview first of the evidence supporting the existence of open knowledge disclosure and second of the economic motivations that encourage rational, profit seeking firms to adopt these behaviours. [source]


    Michael Rutter
    First page of article [source]


    The web is having a significant impact on how firms interact with each other and their customers. Past stumbling blocks for supply chain integration such as high transaction costs between partners, poor information availability, and the challenges of managing complex interfaces between functional organizations are all dissolving on the web. In this paper, we examine how the web is changing supply chain management. We present a survey of emerging research on the impact of e-business on supply chain management including descriptive frameworks, analytical models, empirical analysis, and case studies. We classify the work into three major categories: e-commerce, e-procurement, and e-col-laboration. [source]

    Role of mechanical factors in governing muscle blood flow

    ACTA PHYSIOLOGICA, Issue 4 2010
    D. D. Sheriff
    Overview This study evaluates how mechanical factors impact cardiac output at the systemic level, and how mechanical factors influence muscle blood flow at the local level. Importantly, the two are intertwined; events that work locally in the periphery to augment muscle blood flow can also act centrally to contribute to the development of a high cardiac output. [source]

    Comparative Overview of Cardiac Output Measurement Methods: Has Impedance Cardiography Come of Age?

    Anthony N. De Maria MD
    Cardiac output, usually expressed as liters of blood ejected by the left ventricle per minute, is a fundamental measure of the adequacy of myocardial function to meet the perfusion needs of tissue at any time. Decreases in cardiac output over time (when cardiac output is measured under similar conditions) may signal myocardial functional deterioration and the onset or progression of heart failure. Conversely, improvements in cardiac output may indicate a positive response to medical therapy. However, most methods for evaluating cardiac output are technically demanding, require specialized training and specialized environments for measurement, and are costly. Therefore, most measurement techniques are impractical for routine evaluation of disease progression and/or response to treatment in the prevention and/or management of heart failure. This paper provides a comparative overview of commonly employed cardiac output measurement strategies with emphasis on developments in impedance cardiography which suggest that impedance cardiography has the potential to make routine assessment and trending of cardiac output a viable alternative to assist in the management of both chronically and acutely ill patients, including those with heart failure. [source]

    Decision Sciences Research in China: A Critical Review and Research Agenda,Foundations and Overview,

    DECISION SCIENCES, Issue 4 2006
    Xiande Zhao
    ABSTRACT This article focuses on decision sciences research in China, providing an overview of current research and developing a foundation for future China-based research. China provides a unique research opportunity for decision sciences researchers, owing to its recent history, rapid economic development, and strong national culture. We examine recent economic reforms and their impact on the development of research questions in the decision sciences, as well as discuss characteristics of the diverse regions in China and their potential as sites for various types of research. We provide a brief overview of recent China-based research on decision sciences issues relating to national culture, supply chain management, quality management, production planning and control, operations strategy, and new product development and discuss some of the unique methodological challenges inherent in China-based research. We conclude by looking forward to emerging research opportunities in China. [source]

    Overview of lasers and their properties

    A. J. Stratigos
    First page of article [source]

    Agrifood Sector Liberalisation and the Rise of Supermarkets in Former State-controlled Economies: A Comparative Overview

    Thomas Reardon
    Former state-controlled economies (FSCEs) have become the most important destination of global retail chain investments. These economies, which spread from North Africa, across Central and Eastern Europe, to East Asia, include more than one and a half billion consumers and a large share of the world's agricultural area and poor farmers. They have undergone an often radical transformation of their agrifood system over the past decade. The take-off of supermarkets in FSCEs started seriously in the mid-late 1990s, and is now moving fast. This article compares FSCE experience in the supermarket revolution and considers its implications for policy-makers and rural development practitioners. [source]

    Overview of retinoid metabolism and function

    Rune Blomhoff
    Abstract Retinoids (vitamin A) are crucial for most forms of life. In chordates, they have important roles in the developing nervous system and notochord and many other embryonic structures, as well as in maintenance of epithelial surfaces, immune competence, and reproduction. The ability of all- trans retinoic acid to regulate expression of several hundred genes through binding to nuclear transcription factors is believed to mediate most of these functions. The role of all- trans retinoic may extend beyond the regulation of gene transcription because a large number of noncoding RNAs also are regulated by retinoic acid. Additionally, extra-nuclear mechanisms of action of retinoids are also being identified. In organisms ranging from prokaryotes to humans, retinal is covalently linked to G protein-coupled transmembrane receptors called opsins. These receptors function as light-driven ion pumps, mediators of phototaxis, or photosensory pigments. In vertebrates phototransduction is initiated by a photochemical reaction where opsin-bound 11- cis -retinal is isomerized to all- trans -retinal. The photosensitive receptor is restored via the retinoid visual cycle. Multiple genes encoding components of this cycle have been identified and linked to many human retinal diseases. Central aspects of vitamin A absorption, enzymatic oxidation of all- trans retinol to all- trans retinal and all- trans retinoic acid, and esterification of all- trans retinol have been clarified. Furthermore, specific binding proteins are involved in several of these enzymatic processes as well as in delivery of all- trans retinoic acid to nuclear receptors. Thus, substantial progress has been made in our understanding of retinoid metabolism and function. This insight has improved our view of retinoids as critical molecules in vision, normal embryonic development, and in control of cellular growth, differentiation, and death throughout life. © 2006 Wiley Periodicals, Inc. J Neurobiol 66: 606,630, 2006 [source]

    NGO Initiatives in Risk Reduction: An Overview

    DISASTERS, Issue 3 2001
    Charlotte Benson
    NGOs appear to be well placed to play a significant role in natural disaster mitigation and preparedness (DMP), working, as they do, with poorer and marginalised groups in society. However, there is little information on the scale or nature of NGO DMP activities. This paper reports the findings of a study seeking to address that gap. It confirms that NGOs are involved in a diverse range of DMP activities but that a number of them are not labelled as such. Moreover, evidence of the demonstrable quality and benefits of DMP involvement is poor. The paper concludes that a number of problems need to be overcome before DMP can be satisfactorily mainstreamed into NGO development and post-disaster rehabilitation programmes. However, there are some early indications of momentum for change. [source]

    Overview of interventions to enhance primary-care provider management of patients with substance-use disorders

    Abstract Issues. Despite the evidence for the effectiveness and cost-effectiveness of interventions to manage substance use disorders, which are common presenting complaints in primary care, primary-care providers find managing substance use disorders a difficult business. This paper provides an overview of the evidence for interventions, including training and education programmes, in enhancing the management of alcohol- and tobacco-use disorders by health-care providers. Approach. The Cochrane Library and the database of the Cochrane Effective Practice and Organisation of Care Group were searched for answers to five questions: (i) Can education and training increase the involvement of primary care providers? (ii) Can education and training cause harm? (iii) Can education and training be enhanced with support and other organisational factors? (iv) Can finance systems change provider behaviour? and (v) Is political support needed? Key Findings. Education and training can increase the involvement of primary-care providers in managing alcohol- and tobacco-use disorders, with the impact enhanced by additional support and other organisational factors. There is some evidence that if education and training does not take account of providers' attitudes, then harm can be caused. There is limited evidence that finance systems can change provider behaviour, and that comprehensive policy, in which a health sector response is a part, can increase the potential of primary-care management of alcohol- and tobacco-use disorders. Conclusions. Tailored education and training programmes for the management of alcohol- and tobacco-use disorders need to be broadly implemented and embedded in overall comprehensive policies that provide the necessary organisational and financial incentives for enhancing provider behaviour. There is an urgent need to extend the evidence base on the impact of education and training and other strategies to increase the involvement of providers in managing substance-use disorders.[Anderson P. Overview of interventions to enhance primary-care provider management of patients with substance-use disorders. Drug Alcohol Rev 2009;28:567,574] [source]

    Overview of treatment of acute migraine

    Arthur H. Elkind
    Abstract Acute migraine is a major public health problem with a significant economic burden secondary to short-term disability and absenteeism. Treatment of acute migraine is always challenging for primary care physicians and family practitioners, as there are no set universal guidelines for the treatment of acute migraine. In acute migraine treatment, nonsteroidal anti-inflammatory drugs (NSAIDs), migraine-specific medications, and adjunctive medications are used, depending on the severity of acute migraine attacks. Treatment of acute migraine has changed drastically since the introduction of the triptans. However, even after the introduction of triptans, nearly one-half of migraine sufferers are still being treated with over-the-counter medications. In this literature review, we mention drugs that are being used in the treatment of acute migraine and their level of evidence recommended by the U.S. Headache Consortium. This article gives special emphasis to pharmacokinetics and clinical characteristics of all available triptans. Drug Dev Res 68:441,448, 2007. © 2008 Wiley-Liss, Inc. [source]

    Ultrasonically Enhanced Voltammetric Analysis and Applications: An Overview

    ELECTROANALYSIS, Issue 5-6 2003
    Abstract Ultrasonically enhanced voltammetric measurements have been successfully applied for the detection of a wide range of trace metals. These are reviewed and the beneficial effects of power ultrasound applied to electroanalysis highlighted, most notably the possibility for quantitative analysis in otherwise highly passivating media, where classical electrochemical techniques often fail. [source]

    Gene,environment interactions and alcohol use and dependence: current status and future challenges

    ADDICTION, Issue 6 2009
    Carmen S. Van Der Zwaluw
    ABSTRACT Aim To discuss the current status of gene,environment interaction research with regard to alcohol use and dependence. Further, we highlight the difficulties concerning gene,environment studies. Methods Overview of the current evidence for gene,environment interactions in alcohol outcomes, and of the associated challenges in gene,environment studies. Results Attention to the causative roles of gene,environment interactions in alcohol use and dependence is increasing. Studies with twin designs are beginning to examine gene-shared environment effects, and animal studies have investigated gene,environment interaction effects on alcohol intake in primates. Thirteen studies incorporated gene,environment interactions in examining alcohol use or dependence in humans. These studies held a variety of candidate genes and environmental risk factors and their heterogeneity made it impossible to draw firm general conclusions. Conclusions Challenges for future gene,environment studies are abundant, and consist of, for example, the development of clear theoretical assumptions about neurobiological mechanisms and the recruitment of large longitudinal samples that already start in childhood. Replication is essential to prevent an overload of false-positive results. Despite the difficulties, it is crucial to include gene,environment interactions in future studies in order to unravel the aetiological factors of human alcohol outcomes. [source]

    Bog Iron Ores and their Potential Role in Arsenic Dynamics: An Overview and a "Paleo Example"

    A. Banning
    Abstract Bog iron ores (BIOs), i.e. terrestrial accumulations of iron (Fe) minerals forming within the zone of groundwater oscillation, have been described in several regions in Germany and other countries. Since BIOs are composed of a variety of Fe minerals, primarily amorphous Fe hydroxides, they are likely to have an influence on the arsenic (As) dynamics of an area, as these minerals represent important natural As sources and sinks. In this study, mineralogical research results (XRD, microscopy) of altered BIOs of Tertiary age ("paleo" BIOs or PBIOs), occurring within Cretaceous sands in an area of North Rhine-Westphalia, are briefly presented. Genesis and mineralogical evolution of the categorized five different types of PBIOs, along with hydrogeochemical data from the literature, are discussed and compared to studies describing Holocene BIOs from other areas. In doing so, striking similarities (depositional environment, substratum, Fe source and its transport, geochemical evolution, and mineralogy) became evident. Differences in mineralogical and chemical composition can be attributed to the longer period of oxidation that the PBIOs have undergone (Fe hydroxide "aging"). This process is still ongoing (most of the groundwaters in the area plot in the goethite stability field) and leads to a higher stability of the Fe phases and thus, a stronger As retention. The known impact of the PBIOs on the As budget of the study area (they represent the source for elevated As concentrations in soils) can be transferred to more recent environments fostering BIO formation. These are likely to be even more important As sinks , and sources , as they contain higher Fe concentrations, higher shares of potentially mobile As and highly variable redox conditions which might lead to an As output from the BIOs into groundwater, soils and plants. Therefore, BIOs and their potential role in As behaviour are not only of scientific, but also of public interest. [source]

    Increasing business value with landfill gas-to-energy projects: Overview of air emissions and permitting regulations

    Mario G. Cora
    First page of article [source]

    Assessing impacts: Overview on sustainability indicators and metrics

    Dicksen Tanzil
    First page of article [source]

    Overview and Perspectives of Employment in People with Epilepsy

    EPILEPSIA, Issue 2005
    Hanneke M. De Boer
    Summary:, Even though it is now the viewpoint of the majority of professionals working in epilepsy care that most people with epilepsy should and can perform on the labor market as does anybody else, research tells a different story. Most figures concerning employment rates of people with epilepsy indicate that they do not perform as well on the labor market as others do. Although both research figures and research groups vary, generally unemployment rates are higher for people with epilepsy than for the general population. Early studies showed that the situation for people with epilepsy was rather grim. Later studies showed similar outcomes. Unemployment rates vary between groups and countries. Research shows that being employed is an important ingredient of the quality of life of people with epilepsy. The World Health Organization also recognizes the importance of employment as a part of social health, and therefore, improving the quality of life. It is important to know the perspectives on the labor market for people with epilepsy and what the possible problems are. I describe a Dutch research project and give an overview of the findings concerning the employment and consequent employability of people with epilepsy and questions pertaining to employment and epilepsy. Possible interventions [i.e., public education and employment programs for people with epilepsy with the aim to improve the (re)integration of people with epilepsy into the labor market, thus improving the quality of life of (potential) employees with epilepsy], are described extensively. [source]

    Overview of the use of antimicrobials for the treatment of bacterial infections in horses

    E. F. Haggett
    Summary Use of antimicrobial drugs is central to the treatment of primary and secondary bacterial infection in horses. When selecting an antimicrobial to treat confirmed or suspected bacterial infection multiple factors should be considered, including: the likely infectious agent; distribution and dosage of selected drugs; mechanisms of action; and potential side effects. Many of these issues will be covered in subsequent articles in this series. The aim of this paper is to aid the clinician in the rational selection of antimicrobials by reviewing the mode of action, spectrum of activity, pharmacokinetics, pharmacodynamics, indications and potential side effects of the main classes of antimicrobial drugs. Extralabel use of drugs is common in veterinary medicine due to a lack of licensed products. This increases the importance of a thorough understanding of antimicrobials and their possible adverse effects. [source]

    An Overview of the Anatomy of Crystal Plasticity Models

    Georges Cailletaud
    Abstract Single crystals, polycrystals, and DS alloys can be modeled in the same framework by means of crystal plasticity. This paper wants to show the common features of the different approaches on the grain level, and the additional assumptions that are needed to derive polycrystal or DS models. Phenomenological rules are introduced for representing the hardening in the single crystal constitutive equations. Series of examples are given to illustrate the capabilities of the various approaches that are mainly related to the crystallographic character, and to the fact that the macroscopic yield locus is not predefined, but built from a collection of linear yield conditions. [source]

    Capuchin monkey tool use: Overview and implications

    Eduardo B. Ottoni
    Abstract Nutcracking capuchins are mentioned in reports dating as far back as the sixteenth century,1, 2 as well as in Brazilian folklore.3 However, it was barely a decade ago that primatologists "discovered" the spontaneous use of stones to crack nuts in a semi-free ranging group of tufted capuchin monkeys. Since then, we have found several more capuchin populations in savanna-like environments which employ this form of tool use.5,7 The evidence so far only weakly supports genetically based behavioral differences between populations and does not suggest that dietary pressures in poor environments are proximate determinants of the likelihood of tool use. Instead, tool use within these capuchin populations seems to be a behavioral tradition that is socially learned and is primarily associated with more terrestrial habits. However, differences in the diversity of "tool kits" between populations remain to be understood. [source]

    Overview of adverse reactions to nefopam: an analysis of the French Pharmacovigilance database

    G. Durrieu
    Abstract Nefopam is widely used for the relief of moderate acute pain. Its safety profile remains to be specified. The objective of the study was to review adverse reactions to nefopam spontaneously reported to the French Pharmacovigilance system. All cases of adverse drug reactions (ADRs) associated with nefopam, registered in the French Pharmacovigilance database from January 1, 1995 to December 31, 2004, were reviewed. For each reported ADR, information about patient (age, gender, medical history), drug exposure (suspected and concomitantly used drugs), characteristics of ADRs (imputability score, time of onset, seriousness, outcome) were collected. A total of 114 ADRs with an imputability rated from ,plausible' (I2) to ,likely' (I3) and ,very likely' (I4) was analysed. The most frequent ADRs included ,expected' ADRs such as sweating, nausea, tachycardia, malaise or vomiting; 61 ADRs were ,unexpected. No overdose was reported; 26 ADRs (23%) were considered as ,serious'. Most of them were ,unexpected', including neuropsychiatric (hallucinations, convulsions) or cutaneous (pruritus, erythema, urticaria) ADRs. Six cases of anaphylactic ADRs (two angioedema and four anaphylactic shocks) were reported, all occurring shortly after use of nefopam during the post-operative period. Physicians should be aware of the possible occurrence of some serious ADRs when using nefopam such as convulsions and anaphylactic shocks, especially when the drug is used in special medical conditions, like post-operative periods. [source]

    Rural Youth Migration Trends in Australia: an Overview of Recent Trends and Two Inland Case Studies

    Abstract Much of what has been written on the topic of Australian rural youth migration trends and processes has often proceeded from data-free, or data-poor grounds. In this context, this paper analyses recent trends in youth (15 to 24 years of age) migration for a temporally-consistent set of Statistical Divisions (SDs) in inland rural Australia, and for local government areas within the Northern Tablelands and Slopes and Ranges of northern New South Wales and the Western Australian Central Wheatbelt. The paper finds that rates of youth loss from rural regions have increased over the past twenty years. Yet the patterns, processes, causes and impacts of rural youth migration are distributed in a spatially-uneven fashion. Some remote areas are receiving net migration gains while booming ,sea change' coastal regions have experienced heavy losses. While the ,flight to the bright city lights' syndrome is evident, relatively high proportions of young people in the Northern SD of NSW move within their immediate region. Nevertheless, some common understandings concerning youth mobility were also confirmed. Gender differentials in migration propensity between women and men are evident even at quite local scales. Young people are also more likely to search out capital cities than the rest of the population. Most inland areas still continue to experience heavy losses of local youth. A more precise understanding of rural youth migration trends is an important stepping stone in the establishment of a reinvigorated research effort into young rural people's perspectives of their changing life chances in their home communities. [source]

    A Methodological Overview of Network Vulnerability Analysis

    GROWTH AND CHANGE, Issue 4 2008
    ABSTRACT Evaluating network infrastructures for potential vulnerabilities is an important component of strategic planning, particularly in the context of managing and mitigating service disruptions. Many methods have been proposed to facilitate such analysis, providing different interpretations of infrastructure vulnerability. The primary approaches that have been employed for network vulnerability analysis can be broadly classified as scenario-specific, strategy-specific, simulation, and mathematical modeling methodologies. Research on network vulnerability assessment has traditionally focused on one of these methodologies without consideration of the others. This article highlights the important implications of methodology for both infrastructure planning and policy development. To better understand the theoretical and practical trade-offs associated with methodology selection, this article provides a review of these categories of analysis, examining benefits and shortcomings with regard to practical planning issues and policy interpretation. [source]