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State-of-the-art
Kinds of State-of-the-art Terms modified by State-of-the-art Selected AbstractsState-of-the-Art in Longitudinal Studies on Aging: An Overview of the SupplementJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 2010Ruth M. Tappen RN The articles in this supplement are based on a conference held in January 2008 sponsored by a grant from the Robert Wood Johnson Foundation. The purpose of the conference was to summarize major findings and methodological issues in previous and ongoing longitudinal studies on aging and to identify potentially fruitful areas for future research. This article is a review and synthesis of the articles in this supplement. Each of the articles makes important contributions to summarizing existing research, identifying challenging methodological issues, or proposing areas that should be explored in future research. Three themes were identified: general improvement in the health status of the population aged 65 and older in the United States, a shift in longitudinal research on aging from a focus on the endpoints of disease to a focus on the preclinical stage and underlying mechanisms of these diseases, and contemporary developments in longitudinal research methodology. A number of practical suggestions were also drawn from the articles reviewed. [source] Microwave-Assisted Polymer Synthesis: State-of-the-Art and Future PerspectivesMACROMOLECULAR RAPID COMMUNICATIONS, Issue 20 2004Frank Wiesbrock Abstract Summary: Monomodal microwaves have overcome the safety uncertainties associated with the precedent domestic microwave ovens. After fast acceptance in inorganic and organic syntheses, polymer chemists have also recently discovered this new kind of microwave reactor. An almost exponential increase of the number of publications in this field reflects the steadily growing interest in the use of microwave irradiation for polymerizations. This review introduces the microwave systems and their applications in polymer syntheses, covering step-growth and ring-opening, as well as radical polymerization processes, in order to summarize the hitherto realized polymerizations. Special attention is paid to the differences between microwave-assisted and conventional heating as well as the "microwave effects". Results of search on number of publications on microwave-assisted polymerizations, sorted by year. [source] Proceedings of the 8th Conference on Optics of Excitons in Confined Systems (OECS-8)PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 3 2004Roberto CingolaniArticle first published online: 9 FEB 200 The 8th Conference on Optics of Confined Systems (OECS-8), 15,17 September 2003 in Lecce, Italy, continued a series of traditional world wide meetings which regroup scientists active in the area of exciton spectroscopy and physics, confined systems, and nanostructures. The conference addressed basic and applied physics aspects, material issues, and device concepts in a multidisciplinary community. State-of-the-art results in the field of exciton physics in inorganic as well as organic confined systems were discussed and compared. [source] State-of-the-art staging in prostate cancerBJU INTERNATIONAL, Issue 5 2001B.A. Wilkinson First page of article [source] Principles and Applications of Computer Graphics in MedicineCOMPUTER GRAPHICS FORUM, Issue 1 2006F.P. Vidal Abstract The medical domain provides excellent opportunities for the application of computer graphics, visualization and virtual environments, with the potential to help improve healthcare and bring benefits to patients. This survey paper provides a comprehensive overview of the state-of-the-art in this exciting field. It has been written from the perspective of both computer scientists and practising clinicians and documents past and current successes together with the challenges that lie ahead. The article begins with a description of the software algorithms and techniques that allow visualization of and interaction with medical data. Example applications from research projects and commercially available products are listed, including educational tools; diagnostic aids; virtual endoscopy; planning aids; guidance aids; skills training; computer augmented reality and use of high performance computing. The final section of the paper summarizes the current issues and looks ahead to future developments. [source] MRMOGA: a new parallel multi-objective evolutionary algorithm based on the use of multiple resolutionsCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 4 2007Antonio López Jaimes Abstract In this paper, we introduce MRMOGA (Multiple Resolution Multi-Objective Genetic Algorithm), a new parallel multi-objective evolutionary algorithm which is based on an injection island approach. This approach is characterized by adopting an encoding of solutions which uses a different resolution for each island. This approach allows us to divide the decision variable space into well-defined overlapped regions to achieve an efficient use of multiple processors. Also, this approach guarantees that the processors only generate solutions within their assigned region. In order to assess the performance of our proposed approach, we compare it to a parallel version of an algorithm that is representative of the state-of-the-art in the area, using standard test functions and performance measures reported in the specialized literature. Our results indicate that our proposed approach is a viable alternative to solve multi-objective optimization problems in parallel, particularly when dealing with large search spaces. Copyright © 2006 John Wiley & Sons, Ltd. [source] Continuities and changes in self-change researchADDICTION, Issue 9 2010Harald Klingemann ABSTRACT Aims A substantial literature demonstrates that natural recoveries from substance use disorders not only occur but are a common pathway to recovery. This article reviews selectively and comments on the current state-of-the-art in natural recovery research. Methods Basic concepts in natural recovery research are presented, and topical and methodological trends and changes in self-change research over time are discussed. Conclusions Although considerable progress has occurred in natural recovery research, several topics deserving of further research are identified, and implications for policy practice are discussed. [source] Cover Picture: Electrophoresis 7'09ELECTROPHORESIS, Issue 7 2009Article first published online: 16 APR 200 Issue no. 7 is a special issue on "Biomarker Discovery and Related Topics". It has 18 articles distributed among four parts including genomic, proteomic, glycoproteomic and metabolomic markers. "New separation technologies, improvements of existing methods and intuitive, elegant applications are providing a representative snapshot on the "state-of-the-art" of the bioanalytical aspects of biomarker discovery today". In addition, as recognition of his significant contribution to the field, this special issue is dedicated to the 70th birthday of Professor Barry L. Karger. [source] Implementing life cycle assessment in product developmentENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 4 2003Gurbakhash Singh Bhander The overall aim of this paper is to provide an understanding of the environmental issues involved in the early stages of product development, and the capacity of Life Cycle Assessment (LCA) techniques to address these issues. The paper aims to outline the problems for the designer in evaluating the environmental benignity of a product from the outset, and to provide a framework for decision support based on the performance evaluation at different stages of the design process. The barriers that prevent product developers from using LCA are presented, as well as opportunities for introducing environmental criteria in the design process by meeting the designer's information requirements at the different life cycle stages. This can lead to an in-depth understanding of the attitudes of product developers towards the subject area, and an understanding of possible future directions for product development. This paper introduces an Environmentally Conscious Design method, and presents trade-offs between design degrees of freedom and environmental solutions. Life cycle design frameworks and strategies are also addressed. The paper collects experiences and ideas around the state-of-the-art in eco-design, from literature and personal experience, and provides eco-design life cycle assessment strategies. The end result of this presentation is to define the requirements for performance measurement techniques, and the environment needed to support life cycle evaluation throughout the evaluation of early stages of a product system. [source] The intermediate effect and the diagnostic accuracy in clinical case recall of students and experts in dental medicineEUROPEAN JOURNAL OF DENTAL EDUCATION, Issue 3 2009J. Eberhard Abstract Introduction:, The extensive knowledge of experts facilitates the solving of domain-specific problems. In general, this is due to the fact that experts recall more detailed information than do novices or even advanced students. However, if physicians of different expertise levels are asked to write down the details of a given case, advanced medical students recall more information than experts. This phenomenon was called the ,intermediate effect' and is considered to be a specific feature of medical expertise. The aim of the here presented study was to examine this observation in the domain of dental medicine. Materials and methods:, Sixty-one students and 20 specialised dentists participated in this study. Three clinical case descriptions were presented and afterwards the participants were told to write down all concrete information they remembered. Finally, they had to come up with a diagnosis. Interrater agreement, diagnostic accuracy and the recall explanation protocols were analysed statistically in comparison to state-of-the-art (canonical) explanations of the clinical cases. Results:, The mean interrater agreement was 96.2 ± 3.37%. It was shown statistically that the more experienced the participants, the more accurate their diagnoses were (P < 0.001). The statistical analysis using the Games-Howell test demonstrated significant more written recall of the 5th-year students compared with 3rd- and 4th-year students and experts (P < 0.05). Conclusion:, The results of this study suggest the existence of the intermediate effect in clinical case recall in dental medicine and thereby corroborate its importance and general applicability for different medical domains. [source] Self-Regulated Learning in Technology-Enhanced Learning Environments: lessons of a European peer reviewEUROPEAN JOURNAL OF EDUCATION, Issue 3-4 2006KARL STEFFENS This article first describes the state-of-the-art of model building and empirical research in the field of self-regulated learning (SRL) and then focuses on self-regulated learning in Technology-Enhanced Learning Environments (TELEs). We present recent research results obtained in a European project (TELEPEERS) in the context of which we evaluated TELEs in a peer review manner with respect to their potential for supporting self-regulated learning. In addition, data were obtained on a sample of TELEPEERS students working in these environments and comparative analyses were made across the European project partners. [source] Crystalline , -Alumina Deposited in an Industrial Coating Unit for Demanding Turning Operations,ADVANCED ENGINEERING MATERIALS, Issue 1-2 2010Kirsten Bobzin Crystalline PVD ,-Al2O3 - coatings offer great potential for their use in high-speed cutting operations. They promise high hot hardness and high oxidation resistance at elevated temperatures. This is important for coatings that are used for machining of materials with low thermal conductivity such as stainless steel or Inconel 718 because heat generated during cutting can barely be dissipated by the chip. Because of the prevailing bonding forces of alumina, adhesion-related sticking can be reduced even for dry cutting. Furthermore, the high formation enthalpy of alumina prevents chemical reactions with frictional partners. The present work gives an overview of the deposition of ,-Al2O3 thin films on WC/Co-cutting inserts by using pulsed MSIP (magnetron sputter ion plating) PVD technology. To improve adhesion, a (Ti,Al)N bond coat was employed. The samples were analyzed using common thin film test equipment. Cutting tests and pin-on-disk examinations were carried out to test the coating's performance. For turning operations, the difficult-to-machine austenitic steel 1.4301 (X5CrNi18-10) was used. In comparison to a state-of-the-art (Ti,Al)N coating, (Ti,Al)N/,-Al2O3 showed a longer tool life. [source] A Polycrystalline Approach to the Cyclic Behaviour of f.c.c. Alloys , Intra-Granular HeterogeneityADVANCED ENGINEERING MATERIALS, Issue 9 2009Xavier Feaugas For several decades, the plastic deformation mechanisms of f.c.c. metals under cyclic loading have received considerable attention. The extensive work on this subject has gradually lead to the identification of the physical processes to be included in a formal scheme of fatigue behavior. Accordingly, we propose a review of the physical mechanisms of plastic deformation in f.c.c. metals and alloys to define the state-of-the-art and motivate future studies. The aim is to demonstrate the importance of a good knowledge of the heterogeneous nature of deformation at the intra-granular scale in defining a physical model of cyclic behavior. A large characterization of the different stages associated with the evolution of heterogeneous dislocation structures during tensile and cyclic loadings is given for an austenitic stainless steel AISI 316L. A unified view of these various structures is proposed in the form of a modified Pedersen's map [,max,=,f(,pcum), where ,max is the maximum plastic strain and ,pcum the cumulative plastic strain] in the case of tensile loading and different kinds of cyclic loading: uni-axial and multi-axial tests under stress or strain amplitude control. The specificities of each domain defined in the map are discussed in terms of long-range internal stresses in order to formalize, in a simple composite scheme, the intra-granular stress,strain field. The importance of taking into account this scheme and the nature of the different dislocations populations in a polycrystalline model is illustrated. [source] On the fundamental communication abstraction supplied by P2P overlay networksEUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 1 2006Curt Cramer The disruptive advent of peer-to-peer (P2P) file sharing in 2000 attracted significant interest. P2P networks have matured from their initial form, unstructured overlays, to structured overlays like distributed hash tables (DHTs), which are considered state-of-the-art. There are huge efforts to improve their performance. Various P2P applications like distributed storage and application-layer multicast were proposed. However, little effort was spent to understand the communication abstraction P2P overlays supply. Only when it is understood, the reach of P2P ideas will significantly broaden. Furthermore, this clarification reveals novel approaches and highlights future directions. In this paper, we reconsider well-known P2P overlays, linking them to insights from distributed systems research. We conclude that the main communication abstraction is that of a virtual address space or application-specific naming. On this basis, P2P systems build a functional layer implementing, for example lookup, indirection and distributed processing. Our insights led us to identify interesting and unexplored points in the design space. Copyright © 2004 AEI. [source] Graphene Solution-Gated Field-Effect Transistor Array for Sensing ApplicationsADVANCED FUNCTIONAL MATERIALS, Issue 18 2010Markus Dankerl Abstract Graphene, with its unique combination of physical and electronic properties, holds great promise for biosensor and bioelectronic applications. In this respect, the development of graphene solution-gated field-effect transistor (SGFET) arrays capable of operation in aqueous environments will establish the real potential of graphene in this rapidly emerging field. Here, we report on a facile route for the scalable fabrication of such graphene transistor arrays and provide a comprehensive characterization of their operation in aqueous electrolytes. An on-chip structure for Hall-effect measurements allows the direct determination of charge carrier concentrations and mobilities under electrolyte gate control. The effect of the solution-gate potential on the electronic properties of graphene is explained using a model that considers the microscopic structure of water at the graphene/electrolyte interface. The graphene SGFETs exhibit a high transconductance and correspondingly high sensitivity, together with an effective gate noise as low as tens of ,V. Our study demonstrates that graphene SGFETs, with their facile technology, high transconductance, and low noise promise to far outperform state-of-the-art Si-based devices for biosensor and bioelectronic applications. [source] Bottom-Up Engineering of Subnanometer Copper Diffusion Barriers Using NH2 -Derived Self-Assembled MonolayersADVANCED FUNCTIONAL MATERIALS, Issue 7 2010Arantxa Maestre Caro Abstract A 3-aminopropyltrimethoxysilane-derived self-assembled monolayer (NH2SAM) is investigated as a barrier against copper diffusion for application in back-end-of-line (BEOL) technology. The essential characteristics studied include thermal stability to BEOL processing, inhibition of copper diffusion, and adhesion to both the underlying SiO2 dielectric substrate and the Cu over-layer. Time-of-flight secondary ion mass spectrometry and X-ray spectroscopy (XPS) analysis reveal that the copper over-layer closes at 1,2-nm thickness, comparable with the 1.3-nm closure of state-of-the-art Ta/TaN Cu diffusion barriers. That the NH2SAM remains intact upon Cu deposition and subsequent annealing is unambiguously revealed by energy-filtered transmission electron microscopy supported by XPS. The SAM forms a well-defined carbon-rich interface with the Cu over-layer and electron energy loss spectroscopy shows no evidence of Cu penetration into the SAM. Interestingly, the adhesion of the Cu/NH2SAM/SiO2 system increases with annealing temperature up to 7.2,J m,2 at 400,°C, comparable to Ta/TaN (7.5,J m,2 at room temperature). The corresponding fracture analysis shows that when failure does occur it is located at the Cu/SAM interface. Overall, these results demonstrate that NH2SAM is a suitable candidate for subnanometer-scale diffusion barrier application in a selective coating for copper advanced interconnects. [source] Development Section, April 2008GEOGRAPHY COMPASS (ELECTRONIC), Issue 3 2008Cheryl McEwan EDITORIAL It is a great privilege to serve as Editor for the Development section of Geography Compass. The journal is an exciting new venture in electronic publishing that aims to publish state-of-the-art peer-reviewed surveys of key contemporary issues in geographical scholarship. As the first Editor of this section, it is my responsibility to establish the key aims and innovations for this section of the journal. These include: publishing reviews of scholarship on topics of contemporary relevance that are accessible and useful to researchers, teachers, students and practitioners; developing the range of topics covered across the spectrum of development geography; helping to set agendas in development geography by identifying gaps in existing empirical and conceptual research; commissioning articles from both established and graduate/early career researchers who are working at the frontiers of development geography; and communicating the distinctiveness of Geography Compass. Part of this distinctiveness is in publishing articles that are both of scholarly excellence and accessible to a wide audience. The first volume of Geography Compass was published in 2007, covering a wide range of topics (e.g. migration, children, technology, grassroots women's organizations, civil society, biodiversity, tourism, inequality, agrarian change, participatory development, disability, spirituality) in a number of specific geographical areas (e.g. Africa/southern Africa, Caribbean, China, Peru). Forthcoming in 2008/2009 are articles on the Gambia, Latin America, the Philippines, Southeast Asia, Bangladesh and South Africa, focusing on topics such as food security, comparative post-socialism, foreign aid and fair trade. Building on these diverse and excellent articles, I plan to communicate the distinctiveness of Development in a number of ways. First, I encourage an ecumenical approach to the notion of ,development geography' and welcome contributions from scholars across a range of social science disciplines whose work would be useful to a geography audience. This is important, not least because both development and geography, in disciplinary terms, are largely European inventions. Many scholars in Latin America, Africa and Asia, for example, do not refer to themselves as either development specialists or geographers but are producing important research in areas of direct relevance to students and researchers of ,development geography'. As the first editions illustrate, I also seek to publish articles that reflect ,development' in its broadest sense, encompassing economic, (geo)political, social, cultural and environmental issues. 2008 will be an interesting year for development, with a number of important issues and events shaping discourse and policy. These include: the Beijing Olympics and increasing focus on China's role in international development; political change in a number of African countries (Kenya, Zimbabwe, South Africa); the US presidential elections and potential shifts in policy on climate change, trade and security; the impacts of the Bali roadmap on climate change in the current economic context; the increasing number of impoverished people in Asia (notably China and India), sub-Saharan Africa and Latin America (notably Brazil) that even the World Bank has acknowledged; the implications of the increasing role of philanthropic foundations (e.g. the Gates Foundation and those emerging in India and Russia) in international development. I hope to see some of these issues covered in this journal. Second, I am keen to break down the association between ,development' and parts of the world variously categorized as ,Third World', ,Global South' or ,Developing World' by publishing articles that cut across North and South, East and West. The intellectual and disciplinary practices within (Western) geography that separate those researching issues in the South and post-socialist contexts from those researching similar issues in advanced capitalist economies are, it seems, no longer sustainable or sensible. Moreover, while studies of transnational and ethical trade, neoliberalism, household economies and ,commodity chains', for example, incorporate a multitude of case studies from across the world, these tend to be understood through conceptual lenses that almost always have their theoretical antecedents in Western theorization. The notion of ,learning from' debates, policy and practice in other parts of the world is still relatively alien within the discipline. There are thus issues in how we research and teach ethically and responsibly in and about different parts of the world, and in which this journal might make a contribution. Third, and related, part of my responsibility is to ensure that Compass reflects the breadth of debate about ,development' by publishing articles written by a truly international range of scholars. This has proved to be a challenge to date, in part reflecting the newness of the journal and the difficulties posed by English language publication. However, an immediate aim is to publish the work and ideas of scholars based outside of Anglophone contexts, in the Global South and in post-socialist contexts, and to use international referees who are able to provide valuable commentaries on the articles. A longer-term aim is to also further internationalize the Editorial Board. Currently, one-third of the Editorial Board is non-UK and I plan to increase this to at least 50% in future. Fourth, I plan to ensure that the Development section takes full advantage of electronic publication and the opportunities this offers. Thus, while I am keen to retain a word limit in the interest of publishing accessible articles, the lack of constraint regarding page space enables authors to include a wide range of illustrative and other material that is impossible in print journals. I plan to encourage authors to make greater use of visual materials (maps, photographs/photo-essays, video, sound recordings, model simulations and datasets) alongside text as well as more innovative forms of presentation where this might be appropriate. Finally, in the coming year, I intend to work more closely with other Compass section Editors to realize the potential for fostering debate that cuts across subdisciplinary and even disciplinary boundaries. The journal publishes across the full spectrum of the discipline and there is thus scope for publishing articles and/or special issues on development-related topics that might best be approached through dialogue between the natural and social sciences. Such topics might include resources (e.g. water, oil, bio-fuels), hazard and risk (from environmental issues to human and state security), and sustainability and quality of life (planned for 2008). Part of the distinctiveness of Compass is that electronic-only publication ensures that articles are published in relatively quick time , in some cases less than 3 months from initial submission to publication. It thus provides an important outlet for researchers working in fast-changing contexts and for those, such as graduate and early-career researchers, who might require swift publication for career purposes. Of course, as Editor I am reliant on referees both engaging with Manuscript Central and providing reports on articles in a relatively short space of time to fully expedite the process. My experience so far has been generally very positive and I would like to thank the referees for working within the spirit of the journal. Editing a journal is, of course, a collaborative and shared endeavour. The Development Editorial Board has been central to the successful launch of Development by working so generously to highlight topics and potential authors and to review articles; I would like to take this opportunity to thank Tony Bebbington, Reg Cline-Cole, Sara Kindon, Claire Mercer, Giles Mohan, Warwick Murray, Richa Nagar, Rob Potter, Saraswati Raju, Jonathan Rigg, Jenny Robinson and Alison Stenning. The Editors-in-Chief , Mike Bradshaw and Basil Gomez , have provided invaluable advice while adding humour (and colour) to the editorial process. Colleagues at Wiley-Blackwell have provided superb support, in particular, Helen Ashton who is constantly on hand to provide advice and assistance. I look forward to working closely with these people again in the coming year, as well as with the authors and readers who are vital to ensuring that Geography Compass fulfils its remit. [source] A new global biome reconstruction and data-model comparison for the Middle PlioceneGLOBAL ECOLOGY, Issue 3 2008U. Salzmann ABSTRACT Aim, To produce a robust, comprehensive global biome reconstruction for the Middle Pliocene (c. 3.6,2.6 Ma), which is based on an internally consistent palaeobotanical data set and a state-of-the-art coupled climate,vegetation model. The reconstruction gives a more rigorous picture of climate and environmental change during the Middle Pliocene and provides a new boundary condition for future general circulation model (GCM) studies. Location, Global. Methods, Compilation of Middle Pliocene vegetation data from 202 marine and terrestrial sites into the comprehensive GIS data base TEVIS (Tertiary Environmental Information System). Translation into an internally consistent classification scheme using 28 biomes. Comparison and synthesis of vegetation reconstruction from palaeodata with the outputs of the mechanistically based BIOME4 model forced by climatology derived from the HadAM3 GCM. Results, The model results compare favourably with available palaeodata and highlight the importance of employing vegetation,climate feedbacks and the anomaly method in biome models. Both the vegetation reconstruction from palaeobotanical data and the BIOME4 prediction indicate a general warmer and moister climate for the Middle Pliocene. Evergreen taiga as well as temperate forest and grassland shifted northward, resulting in much reduced tundra vegetation. Warm-temperate forests (with subtropical taxa) spread in mid and eastern Europe and tropical savannas and woodland expanded in Africa and Australia at the expense of deserts. Discrepancies which occurred between data reconstruction and model simulation can be related to: (1) poor spatial model resolution and data coverage; (2) uncertainties in delimiting biomes using climate parameters; or (3) uncertainties in model physics and/or geological boundary conditions. Main conclusions, The new global biome reconstruction combines vegetation reconstruction from palaeobotanical proxies with model simulations. It is an important contribution to the further understanding of climate and vegetation changes during the Middle Pliocene warm interval and will enhance our knowledge about how vegetation may change in the future. [source] Toward the Development of Printable Nanowire Electronics and SensorsADVANCED MATERIALS, Issue 37 2009Zhiyong Fan Abstract In recent years, there has been tremendous progress in the research and development of printable electronics on mechanically flexible substrates based on inorganic active components, which provide high performances and stable device operations at low cost. In this regard, various approaches have been developed for the direct transfer or printing of micro- and nanoscale, inorganic semiconductors on substrates. In this review article, we focus on the recent advancements in the large-scale integration of single crystalline, inorganic-nanowire (NW) arrays for electronic and sensor applications, specifically involving the contact printing of NWs at defined locations. We discuss the advantages, limitations, and the state-of-the-art of this technology, and present an integration platform for future printable, heterogeneous-sensor circuitry based on NW parallel arrays. [source] High-Performance Organic Field-Effect TransistorsADVANCED MATERIALS, Issue 14-15 2009Daniele Braga Abstract With the advent of devices based on single crystals, the performance of organic field-effect transistors has experienced a significant leap, with mobility now in excess of 10,cm2 V,1 s,1. The purpose of this review is to give an overview of the state-of-the-art of these high-performance organic transistors. The paper focuses on the problem of parameter extraction, limitations of the performance by the interfaces, which include the dielectric,semiconductor interface, and the injection and retrieval of charge carriers at the source and drain electrodes. High-performance devices also constitute tools of choice for investigating charge transport phenomena in organic materials. It is shown how the combination of field-effect measurements with other electrical characterizations helps in elucidating this still unresolved issue. [source] The Digital Revolution: A New Paradigm for MicrofluidicsADVANCED MATERIALS, Issue 8 2009Mohamed Abdelgawad Abstract The digital revolution has come to microfluidics. In digital microfluidics (DMF), discrete droplets are manipulated by applying electrical fields to an array of electrodes. In contrast to microchannels, in DMF each sample and reagent is individually addressable, which facilitates exquisite control over chemical reactions. Here, we review the state-of-the-art in DMF, with a discussion of device formats, actuation physics, and biological and nonbiological applications. Along the way, we identify the key players in the field, and speculate on the advances and challenges that lie ahead. As with other fronts in the digital revolution, there have been and will be unexpected developments as DMF matures, but we posit that the future is bright for this promising technology. [source] Detecting trends in tropical rainfall characteristics, 1979,2003INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 8 2007K.-M. Lau Abstract Analyses of two state-of-the-art, blended space-based and ground-based global rainfall data sets from the Global Precipitation Climatology Project (GPCP) and the Climate Prediction Center Merged Analysis Product (CMAP) reveal that there was a significant shift in the probability distribution functions of tropical rainfall during the period 1979,2003. This shift features a positive trend in the occurrence of heavy (top 10% by rain amount) and light (bottom 5%) rain events in the tropics during 1979,2003 and a negative trend in moderate (25,75%) rain events. These trends are consistent in both data sets and are in overall agreement with the Climate Research Unit's (CRU) gauge-only rainfall data over land. The relationships among the trends and the possible long-term changes in rainfall characteristics are discussed. Copyright © 2006 Royal Meteorological Society [source] Fusion of digital television, broadband Internet and mobile communications,Part I: Enabling technologiesINTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 4 2007F. L. C. Ong Abstract The introduction of digital video broadcasting (DVB) satellite systems has become an important tool for future mobile communication and is currently a focus in several research areas such as the integration of DVB satellite systems with different wireless technologies. This tutorial consists of two parts, Enabling technologies and Future service scenarios, which aims to provide an introduction to the current state-of-the-art of DVB standards over satellite and its fusion with mobile and Internet technologies. This paper, Enabling technologies, focuses on providing an overview of the different technologies and issues that facilitates better understanding of the current and future operational scenarios, whereas the second paper, Future service scenarios will emphasize future research directions in this research area. In the first part, the paper will initially be focused on the introduction of different DVB satellite systems, i.e. DVB- via satellite (DVB-S), DVB return channel by satellite (DVB-RCS) and second-generation DVB system for broadband satellite services (DVB-S2). This is then followed by a description of the different Internet Protocol (IP) technologies used to support macro- and micro-mobility and the migration strategies from IP version 4 (IPv4) to IP version 6 (IPv6). Finally, the different security mechanisms for the DVB system and end-to-end satellite network are addressed. Copyright © 2007 John Wiley & Sons, Ltd. [source] To Bridge a Quality Chasm: Connect With the GuidelinesJOURNAL FOR SPECIALISTS IN PEDIATRIC NURSING, Issue 4 2002Carolyn Gallagher ISSUES AND PURPOSE. A wide chasm exists between the care we have and the care we could have. This article will inform nurses about the pediatric quality "chasm" by identifying practice variations from evidence-based guidelines for common childhood conditions. CONCLUSIONS. Nurses are accountable for providing state-of-the-art, evidence-based care to children. The pediatric quality chasm calls for nurses to stand up and speak out for children, to use and develop tools that activate the best scientific knowledge, and to empower parents to make it happen. PRACTICE IMPLICATIONS. Advocacy and patient-centered care are nurses' means to partner with parents and collaborate with colleagues to connect with the guidelines and bridge the quality chasm. [source] A review of the state of the art of personal rapid transitJOURNAL OF ADVANCED TRANSPORTATION, Issue 1 2000Article first published online: 19 JAN 2010, J. Edward Anderson The paper begins with a review of the rational for development of personal rapid transit, the reasons it has taken so long to develop, and the process needed to develop it. Next I show how the PRT concept can be derived from a system-significant equation for life-cycle cost per passenger-mile as the system that minimizes this quantity. In the bulk of the paper I discuss the state-of-the-art of a series of technical issues that had to be resolved during the development of an optimum PRT design. These include capacity, switching, the issue of hanging vs. supported vehicles, guideways, vehicles, control, station operations, system operations, reliability, availability, dependability, safety, the calculation of curved guideways, operational simulation, power and energy. The paper concludes with a listing of the implications for a city that deploys an optimized PRT system. [source] Simulated Computer-Mediated/Video-Interactive Distance Learning: A Test of Motivation, Interaction Satisfaction, Delivery, Learning & Perceived EffectivenessJOURNAL OF COMPUTER-MEDIATED COMMUNICATION, Issue 3 2001Ruth Guzley This paper reports on an innovative, computer-mediated, educational technology application in a simulated distance learning environment. As an initial evaluation, real student groups completed an entire university course using this state-of-the-art, two-way synchronous audio/visual communication technology, Distributed Tutored Video Instruction (DTVI). The study reported here explored student perceptions of a simulated distance learning environment using the system. The learning environment was characterized by videotaped lectures by the course instructor, delivered in computer-mediated small group settings. Six separate groups made up of six to eight students and a facilitator were studied. Group members were in separate locations, interacting via synchronous audio and visual computer channels. Our findings indicate an overall high level of perceived effectiveness and satisfaction with the instructional mode. In addition, significant relationships were established between facilitator effectiveness and student satisfaction, student motivation and class participation, student exam grades and perceived amount of group discussion. Findings indicate innovations in computer-mediated instructional designs can achieve desired levels of participant interaction considered critical to effective distance education technology. [source] The DARPA LAGR program: Goals, challenges, methodology, and phase I resultsJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 11-12 2006L. D. Jackel The DARPA Learning Applied to Ground Vehicles (LAGR) program is accelerating progress in autonomous, perception-based, off-road navigation in unmanned ground vehicles (UGVs) by incorporating learned behaviors. In addition, the program is using passive optical systems to accomplish long-range scene analysis. By combining long-range perception with learned behavior, LAGR expects to make a qualitative break with the myopic, brittle behavior that characterizes most UGV autonomous navigation in unstructured environments. The very nature of testing navigation in unstructured, off-road environments makes accurate, objective measurement of progress a challenging task. While no absolute measure of performance has been defined by LAGR, the Government Team managing the program has created a relative measure: the Government Team tests navigation software by comparing its effectiveness to that of fixed, but state-of-the-art, navigation software running on a standardized vehicle on a series of varied test courses. Starting in March 2005, eight performers have been submitting navigation code for Government testing on such a standardized Government vehicle. As this text is being written, several teams have already demonstrated leaps in performance. In this paper we report observations on the state of the art in autonomous, off-road UGV navigation, we explain how LAGR intends to change current methods, we discuss the challenges we face in implementing technical aspects of the program, we describe early results, and we suggest where major opportunities for breakthroughs exist as LAGR progresses. © 2007 Wiley Periodicals, Inc. [source] International cooperation on western corn rootworm ecology research: state-of-the-art and future researchAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 1 2009J. Moeser Abstract 1,Invasive pest species are challenging partly because the invasion process may be highly dynamic and because of the lack of knowledge of many researchers, professionals and farmers in the newly-invaded regions. The chrysomelid Diabrotica virgifera virgifera LeConte is such an invasive pest. It has been the main pest of continuous maize in the U.S.A. for more than 60 years and is currently spreading throughout Europe. 2,In the area with a long history of this pest (Central and North America), scientific knowledge concerning the ecology of this pest has accumulated over the last decades. This resource is of great importance to both America and Europe and has to be gathered, shared and adapted to new situations. We therefore examined, both qualitatively and quantitatively, the scientific literature relating to D. virgifera virgifera ecology. 3,The quantitative analysis suggests that research on D. virgifera virgifera ecology is still in its infancy in Europe and suffers from geographical barriers (between Europe and North America and between linguistic areas within Europe) and that scientific communication should be strengthened both between North America and Europe and within Europe. 4,As a first solution to this problem, we introduce three companion review articles that constitute a landmark for D. virgifera virgifera research, enabling European and American scientists and decision-makers to orient themselves and discover new opportunities for research. We also stress that international research cooperation is the most important key to successfully manage invasive species. [source] Contrast-enhanced peripheral MR angiography at 3.0 Tesla: Initial experience with a whole-body scanner in healthy volunteersJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 5 2003Tim Leiner MD Abstract Purpose To report preliminary experience with contrast-enhanced magnetic resonance angiography (CE-MRA) of the peripheral arteries on a 3.0 T whole-body scanner equipped with a prototype body coil. Materials and Methods Four healthy volunteers were imaged on the 3.0 T system and, for comparative purposes, two of the subjects were also imaged on a commercially available 1.5 T whole-body system. To investigate field strength influence on objective image quality, signal-to-noise (SN) and contrast-to-noise (CN) ratios were calculated for named vessels from the infrarenal aorta to the ankles at both field strengths. Comparable imaging protocols were used at both field strengths. In addition, two reviewers, blinded for field strength, gave subjective image quality scores (three-point scale). Results SN and CN ratios were approximately equal on both systems (variation ,9%) for the iliac and proximal upper leg stations. For the popliteal and lower leg stations SN ratios were 36% and 97% higher, and CN ratios were 44% and 127% higher, at 3.0 T. Subjective image quality at 3.0 T was substantially better for the distal upper and lower legs. Conclusion Contrast-enhanced peripheral MRA is possible at 3.0 T when an imaging protocol similar to a current state-of-the-art 1.5 T protocol is used. Objective and subjective image quality at 3.0 T is comparable for the iliac and upper legs but better for the popliteal and lower leg arteries. J. Magn. Reson. Imaging 2003;17:609,614. © 2003 Wiley-Liss, Inc. [source] Role of mathematical modeling on the optimal control of HIV-1 pathogenesisAICHE JOURNAL, Issue 3 2006Marcel Joly Abstract Mathematical modeling of HIV-1 infection has proven to be instrumental for the modern understanding basis of the AIDS pathogenesis, since it offers the unique means to adequately pose hypotheses concerning AIDS dynamics and treatment protocols. Focusing on the HIV-1 subtype-B epidemic, a comprehensive review and discussion of the state-of-the-art in the area is presented. Based on recent results, this multidisciplinary study is then extended to a more in-depth view at the cellular and molecular biology levels that address key issues concerned with the natural history of AIDS, as the basic human anatomic model, the host cell entry of HIV-1, the quantification the HIV-1 infectivity in terms of viral coreceptor specificity, as well as regulation and expression of CCR5 and CXCR4 molecules on the target cell, the T-lymphocyte generation and infection models, and the immune response model. In the sequence, modeling techniques for AIDS pathogenesis are revised and models concerned with either the general HIV-1 dynamics or specifically related to the HIV-1 primary infection are discussed. Ultimately, a general framework for the real-world problem of optimizing the highly active antiretroviral therapy (HAART) benefits is proposed regarding the important questions associated with the drug chemotherapy resistance, side effects and costs. © 2005 American Institute of Chemical Engineers AIChE J, 2006 [source] | |||||||||||||||||||||||||||||||||||||||||||