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Heterogeneous

Distribution by Scientific Domains
Medical Sciences38%
Life Sciences22%
Chemistry11%
Business, Economics, Finance and Accounting6%
Humanities and Social Sciences4%
Earth and Environmental Science3%
Information Science and Computing2%
Engineering2%
Psychology2%
Polymers and Materials Science2%
4 Other Domains8%
Distribution within Medical Sciences
Neurology10%
Dermatology7%
41 Other Subdomains83%

Kinds of Heterogeneous

  • very heterogeneous
    		•

    Terms modified by Heterogeneous

  • heterogeneous agent
  • heterogeneous catalysis
  • heterogeneous catalyst
  • heterogeneous cell population
  • heterogeneous condition
  • heterogeneous data
  • heterogeneous disease
  • heterogeneous disorder
  • heterogeneous disorders
  • heterogeneous distribution
  • heterogeneous entity
  • heterogeneous environment
  • heterogeneous expectation
    		•
  • heterogeneous expression
  • heterogeneous expression pattern
  • heterogeneous firm
  • heterogeneous forest
  • heterogeneous gold catalyst
  • heterogeneous group
  • heterogeneous groups
  • heterogeneous habitat
  • heterogeneous landscapes
  • heterogeneous mass
  • heterogeneous material
  • heterogeneous media
  • heterogeneous mixture
    		•
  • heterogeneous model
  • heterogeneous nature
  • heterogeneous network
  • heterogeneous nuclear ribonucleoprotein k
  • heterogeneous nucleation
  • heterogeneous palladium catalyst
  • heterogeneous pattern
  • heterogeneous phenotype
  • heterogeneous population
  • heterogeneous porous medium
  • heterogeneous preference
  • heterogeneous process
  • heterogeneous reaction
    		•
  • heterogeneous regime
  • heterogeneous resource
  • heterogeneous response
  • heterogeneous sample
  • heterogeneous set
  • heterogeneous solid
  • heterogeneous spectrum
  • heterogeneous structure
  • heterogeneous surface
  • heterogeneous system
  • heterogeneous system koh
  • heterogeneous tissue

    • Selected Abstracts

    Absence Epilepsy with Onset before Age Three Years: A Heterogeneous and Often Severe Condition

    EPILEPSIA, Issue 7 2003
    Yves Chaix
    Summary: Purpose: The classification of epilepsies and epileptic syndromes recognizes three syndromes with typical absences [TA, i.e., childhood and juvenile absence epilepsies (CAE and JAE), and epilepsy with myoclonic absences (EMA), none of which is characterized by onset in early childhood]. Although several other forms of absence epilepsies have been described recently, none concerns infants and very young children, and little is known about the nosology and prognosis of early-onset absences. Methods: We retrospectively selected all cases with onset of absences as the only or major seizure type before age 3 years and ,2 years of follow-up among cases newly referred between 1986 and 2002. Neurospychological assessments (generally IQ measure), behavior patterns, and schooling situations were reviewed for each child. Results: We found 10 patients (7 F, 3 M). No child had sensory or motor deficits: neuroimaging was performed in nine and was normal in eight, with aspecfic findings in one. Only two could be characterized as CAE and EMA, respectively, both with seizure control and a good cognitive outcome. Among the remaining eight cases, four had a fairly homogeneous presentation with predominantly brief absences and clearly asymmetric interictal EEGs. All eight had neuropsychological and/or behavioral difficulties. Three had full seizure control, and five, persisting absences, with a follow-up ranging beetween 2 years 8 months to 9 years 4 months; only one child was older than 12 years. Conclusions: Great heterogeneity exists among absence epilepsies of early onset, which are rare conditions. Only a few patients can be categorized into well-known syndromes. The overall prognosis is poor. Early onset of absences is uncommon, and multicenter studies should help clarify the nosology and prognosis. [source]

    Allylic Amination of Internal Alkynes with Aromatic and Aliphatic Amines Using Polymer-Supported Triphenylphosphane,Palladium Complex as a Heterogeneous and Recyclable Catalyst

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 26 2010
    Yogesh S. Wagh
    Abstract A facile and novel protocol for the allylic amination of internal alkynes with amines by using a polymer-supported triphenylphosphane,palladium complex [PS,TPP,Pd] as a highly active heterogeneous reusable catalyst was developed. The catalyst exhibited remarkable activity and is reusable over five consecutive cycles. The protocol was applicable for a variety of hindered and functionalized aromatic/aliphatic amines and afforded the desired allylic products in good to excellent yield. [source]

    Monetary Policy with Heterogeneous and Misspecified Expectations

    JOURNAL OF MONEY, CREDIT AND BANKING, Issue 1 2009
    MICHELE BERARDI
    adaptive learning; expectations formation; heterogenous expectations; misspecifications; monetary policy In the recent literature on monetary policy and learning, it has been suggested that private sector's expectations should play a role in the policy rule implemented by the central bank, as they could improve the ability of the policymaker to stabilize the economy. Private sector's expectations, in these studies, are often taken to be homogeneous and rational, at least in the limit of a learning process. In this paper, instead, we consider the case in which private agents are heterogeneous in their expectations formation mechanisms and hold heterogeneous expectations in equilibrium. We investigate the impact of this heterogeneity in expectations on central bank's policy implementation and on the ensuing economic outcomes, and the general result that emerges is that the central bank should disregard inaccurate private sector expectations and solely base its policy on the accurate ones. [source]

    Land Market Interactions between Heterogeneous Agents in a Heterogeneous Landscape,Tracing the Macro-Scale Effects of Individual Trade-Offs between Environmental Amenities and Disamenities

    CANADIAN JOURNAL OF AGRICULTURAL ECONOMICS, Issue 4 2009
    Tatiana Filatova
    Heterogeneity in both the spatial environment and economic agents is a crucial driver of land market dynamics. We present an agent-based land market model where land from agriculture use is transferred into urban. The model combines the microeconomic demand, supply, and bidding foundations of spatial economics models with the spatial heterogeneity of spatial econometric models in a single methodological platform. Heterogeneous agents exchange heterogeneous spatial goods via simulated bilateral market interactions. We model a coastal city where both coastal amenities and flooding or erosion disamenities drive land market outcomes, facilitating separate analysis of the effects of each driver on land rents and land development patterns. We also analyze the implications of homogeneous versus heterogeneous but unbiased flood risk perceptions. Since buyers with low risk perceptions drive market outcomes, spatial development under heterogeneous risk perceptions differs qualitatively, with more expansion into risky areas. Our results highlight the shortcomings of policy models based on representative agent assumptions and the importance of including agent-level data in empirical modeling. L'hétérogénéité de l'environnement spatial et des agents économiques constitue un élément moteur crucial de la dynamique du marché foncier. Nous présentons un modèle multi-agent du marché foncier dans lequel des terres agricoles ont été transférées pour des fins urbaines. Le modèle combine les fondements microéconomiques de la demande, de l'offre et des enchères de modèles de l'économie spatiale avec l'hétérogénéité spatiale des modèles de l'économétrie spatiale dans une plateforme méthodologique unique. Les agents hétérogènes échangent des biens hétérogènes par le biais du jeu des forces du marché bilatéral simulé. Nous avons modélisé une ville côtière où les agréments côtiers et les désagréments causés par les inondations ou l'érosion influent sur le marché foncier, facilitant l'analyse individuelle des effets de chaque élément moteur sur les loyers fonciers et les modèles d'aménagement de terrain. Nous avons également analysé les répercussions des perceptions homogènes et hétérogènes mais non biaisées à l'égard du risque d'inondation. Étant donné que les acquéreurs qui ont de faibles perceptions du risque motivent les effets du marché, le développement spatial selon des perceptions hétérogènes à l'égard du risque varie qualitativement, avec plus d'expansion dans les zones à risque. Nos résultats ont mis en lumière les lacunes des modèles de politiques fondés sur les hypothèses d'un agent représentatif et l'importance d'inclure des données sur l'hétérogénéité des agents dans la modélisation empirique. [source]

    Reaction Kinetics of Soybean Oil Transesterification Using Heterogeneous Metal Oxide Catalysts

    CHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 12 2007
    K. Singh
    Abstract Homogeneous acid or base catalysts dissolve fully in the glycerol layer and partially in the fatty acid methyl ester (biodiesel) layer in the triglyceride transesterification process. Heterogeneous (solid) catalysts, on the other hand, can prevent catalyst contamination making product separation much simpler. In the present work, the transesterification kinetics of five different solid catalysts with soybean oil is presented. It is found that heterogeneous catalysts require much higher temperatures and pressures to achieve acceptable conversion levels compared to homogeneous catalysts. Subsequent to preliminary investigations, transesterifications were conducted for selected high performance solid catalysts, i.e., MgO, CaO, BaO, PbO, and MnO2 in a high pressure reactor up to a temperature of 215,°C. The yield of the fatty acid methyl esters and the kinetics (rate constant and order) of the reaction are estimated and are compared for each catalyst. [source]

    ChemInform Abstract: Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones Using Ce(SO4)2,SiO2 as a Heterogeneous and Recyclable Catalyst.

    CHEMINFORM, Issue 40 2010
    Wen Pei
    Abstract Compared with the classical Biginelli reaction, the presented new method has the advantages of better product yields, short reaction time, easy separation and tolerance towards various functional groups. [source]

    ChemInform Abstract: Copper(I) Zeolites as Heterogeneous and Ligand-Free Catalysts: [3 + 2] Cycloaddition of Azomethine Imines.

    CHEMINFORM, Issue 28 2009
    Murielle Keller
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

    4-Aminophenyldiphenylphosphinite (APDPP), a New Heterogeneous and Acid Scavenger Phosphinite , Conversion of Alcohols, Trimethylsilyl, and Tetrahydropyranyl Ethers to Alkyl Halides with Halogens or N-Halosuccinimides.

    CHEMINFORM, Issue 9 2007
    Nasser Iranpoor
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]

    Copper-in-Charcoal (Cu/C): Heterogeneous, Copper-Catalyzed Asymmetric Hydrosilylations.

    CHEMINFORM, Issue 25 2006
    Bruce H. Lipshutz
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]

    Trichloroisocyanuric Acid as a Novel Oxidizing Agent for the Oxidation of Urazoles under Both Heterogeneous and Solvent-Free Conditions.

    CHEMINFORM, Issue 5 2003
    Mohammad Ali Zolfigol
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]

    Heterogeneous Versus Homogeneous Palladium Catalysts for Ligandless Mizoroki,Heck Reactions: A Comparison of Batch/Microwave and Continuous-Flow Processing

    CHEMISTRY - A EUROPEAN JOURNAL, Issue 4 2009

    Abstract Mizoroki,Heck couplings of aryl iodides and bromides with butyl acrylate were investigated as model systems to perform transition-metal-catalyzed transformations in continuous-flow mode. As a suitable ligandless catalyst system for the Mizoroki,Heck couplings both heterogeneous and homogeneous Pd catalysts (Pd/C and Pd acetate) were considered. In batch mode, full conversion with excellent selectivity for coupling was achieved applying high-temperature microwave conditions with Pd levels as low as 10,3,mol,%. In continuous-flow mode with Pd/C as a catalyst, significant Pd leaching from the heterogeneous catalyst was observed as these Mizoroki,Heck couplings proceed by a homogeneous mechanism involving soluble Pd colloids/nanoparticles. By applying low levels of Pd acetate as homogeneous Pd precatalyst, successful continuous-flow Mizoroki,Heck transformations were performed in a high-temperature/pressure flow reactor. For both aryl iodides and bromides, high isolated product yields of the cinnamic esters were obtained. Mechanistic issues involving the Pd-catalyzed Mizoroki,Heck reactions are discussed. [source]

    Electron Transfer to Sulfides and Disulfides: Intrinsic Barriers and Relationship between Heterogeneous and Homogeneous Electron-Transfer Kinetics

    CHEMISTRY - A EUROPEAN JOURNAL, Issue 28 2007
    Belèn Meneses
    Abstract The electron-acceptor properties of series of related sulfides and disulfides were investigated in N,N -dimethylformamide with homogeneous (redox catalysis) and/or heterogeneous (cyclic voltammetry and convolution analysis) electrochemical techniques. The electron-transfer rate constants were determined as a function of the reaction free energy and the corresponding intrinsic barriers were determined. The dependence of relevant thermodynamic and kinetic parameters on substituents was assessed. The kinetic data were also analyzed in relation to corresponding data pertaining to reduction of diaryl disulfides. All investigated reductions take place by stepwise dissociative electron transfer (DET) which causes cleavage of the CalkylS or SS bond. A generalized picture of how the intrinsic electron-transfer barrier depends on molecular features, ring substituents, and the presence of spacers between the frangible bond and aromatic groups was established. The reduction mechanism was found to undergo a progressive (and now predictable) transition between common stepwise DET and DET proceeding through formation of loose radical anions. The intrinsic barriers were compared with available results for ET to several classes of dissociative- and nondissociative-type acceptors, and this led to verification that the heterogeneous and the homogeneous data correlate as predicted by the Hush theory. [source]

    Factors affecting the performance of parallel mining of minimal unique itemsets on diverse architectures

    CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 9 2009
    D. J. Haglin
    Abstract Three parallel implementations of a divide-and-conquer search algorithm (called SUDA2) for finding minimal unique itemsets (MUIs) are compared in this paper. The identification of MUIs is used by national statistics agencies for statistical disclosure assessment. The first parallel implementation adapts SUDA2 to a symmetric multi-processor cluster using the message passing interface (MPI), which we call an MPI cluster; the second optimizes the code for the Cray MTA2 (a shared-memory, multi-threaded architecture) and the third uses a heterogeneous ,group' of workstations connected by LAN. Each implementation considers the parallel structure of SUDA2, and how the subsearch computation times and sequence of subsearches affect load balancing. All three approaches scale with the number of processors, enabling SUDA2 to handle larger problems than before. For example, the MPI implementation is able to achieve nearly two orders of magnitude improvement with 132 processors. Performance results are given for a number of data sets. Copyright © 2009 John Wiley & Sons, Ltd. [source]

    Reliability in grid computing systems,

    CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 8 2009
    Christopher Dabrowski
    Abstract In recent years, grid technology has emerged as an important tool for solving compute-intensive problems within the scientific community and in industry. To further the development and adoption of this technology, researchers and practitioners from different disciplines have collaborated to produce standard specifications for implementing large-scale, interoperable grid systems. The focus of this activity has been the Open Grid Forum, but other standards development organizations have also produced specifications that are used in grid systems. To date, these specifications have provided the basis for a growing number of operational grid systems used in scientific and industrial applications. However, if the growth of grid technology is to continue, it will be important that grid systems also provide high reliability. In particular, it will be critical to ensure that grid systems are reliable as they continue to grow in scale, exhibit greater dynamism, and become more heterogeneous in composition. Ensuring grid system reliability in turn requires that the specifications used to build these systems fully support reliable grid services. This study surveys work on grid reliability that has been done in recent years and reviews progress made toward achieving these goals. The survey identifies important issues and problems that researchers are working to overcome in order to develop reliability methods for large-scale, heterogeneous, dynamic environments. The survey also illuminates reliability issues relating to standard specifications used in grid systems, identifying existing specifications that may need to be evolved and areas where new specifications are needed to better support the reliability. Published in 2009 by John Wiley & Sons, Ltd. [source]

    Service selection and workflow mapping for Grids: an approach exploiting quality-of-service information

    CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 6 2009
    Dimosthenis Kyriazis
    Abstract The advent of heterogeneous and distributed environments, such as Grid environments, made feasible the solution to computational-intensive problems in a reliable and cost-effective manner. In parallel, workflows with increased complexity that require specialized systems to deal with them are emerging, so as to carry out more composite and mission-critical applications. In that rationale, quality-of-service (QoS) issues need to be tackled in order to ensure that each application satisfies the corresponding user requirements. Therefore, considering the quality provision aspect as fundamental for enabling Grid applications to become QoS compliant, we present an approach for service selection using QoS criteria. The latter is achieved with a suite of components that allow the different mappings of application workflow processes to Grid services that not only meet the user goals and requirements but also maximize his/her benefit in terms of the offered QoS level. We also demonstrate the operation of the aforementioned suite of components and evaluate its performance and effectiveness using a Grid scenario, based on a 3D image rendering application. Copyright © 2008 John Wiley & Sons, Ltd. [source]

    Job completion prediction using case-based reasoning for Grid computing environments

    CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 9 2007
    Lilian Noronha Nassif
    Abstract One of the main focuses of Grid computing is solving resource-sharing problems in multi-institutional virtual organizations. In such heterogeneous and distributed environments, selecting the best resource to run a job is a complex task. The solutions currently employed still present numerous challenges and one of them is how to let users know when a job will finish. Consequently, reserve in advance remains unavailable. This article presents a new approach, which makes predictions for job execution time in Grid by applying the case-based reasoning paradigm. The work includes the development of a new case retrieval algorithm involving relevance sequence and similarity degree calculations. The prediction model is part of a multi-agent system that selects the best resource of a computational Grid to run a job. Agents representing candidate resources for job execution make predictions in a distributed and parallel manner. The technique presented here can be used in Grid environments at operation time to assist users with batch job submissions. Experimental results validate the prediction accuracy of the proposed mechanisms, and the performance of our case retrieval algorithm. Copyright © 2006 John Wiley & Sons, Ltd. [source]

    Impact of mixed-parallelism on parallel implementations of the Strassen and Winograd matrix multiplication algorithms

    CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 8 2004
    F. Desprez
    Abstract In this paper we study the impact of the simultaneous exploitation of data- and task-parallelism, so called mixed-parallelism, on the Strassen and Winograd matrix multiplication algorithms. This work takes place in the context of Grid computing and, in particular, in the Client,Agent(s),Server(s) model, where data can already be distributed on the platform. For each of those algorithms, we propose two mixed-parallel implementations. The former follows the phases of the original algorithms while the latter has been designed as the result of a list scheduling algorithm. We give a theoretical comparison, in terms of memory usage and execution time, between our algorithms and classical data-parallel implementations. This analysis is corroborated by experiments. Finally, we give some hints about heterogeneous and recursive versions of our algorithms. Copyright © 2004 John Wiley & Sons, Ltd. [source]

    A stochastic load balancing algorithm for i-Computing

    CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 1 2003
    Yuk-Yin Wong
    Abstract This paper presents a stochastic dynamic load balancing algorithm for Internet computing, which is a new type of distributed computing involving heterogeneous workstations from different organizations on the Internet. To realize the practical environment, we assume the system to be comprised of heterogeneous, untrusted and non-dedicated workstations connected by a non-dedicated network. Our algorithm uses the product of the average processing time and the queue length of system jobs as the load index. Dynamic communication delay is included in the execution cost calculation. The transfer policy and the location policy are combined in a stochastic algorithm. State information exchange is done via information feedback and mutual updating. Simulations demonstrate that our algorithm outperforms conventional approaches over a wide range of system parameters. These results are reconfirmed by empirical experiments after we have implemented the algorithms on the Distributed Java Machine global virtual machine. Copyright © 2003 John Wiley & Sons, Ltd. [source]

    Neurulation in the human embryo revisited

    CONGENITAL ANOMALIES, Issue 2 2000
    Tomoko Nakatsu
    ABSTRACT It used to be widely accepted that neural tube closure in the human initiates at the level of the future neck and proceeds both cranially and caudally like zip fastener closing. This continuous closure model was recently challenged, and observation of human embryos at the neurulation stage revealed that the closure of the human neural tube initiates at multiple sites. Multi-site closure of the neural tube has been observed in many other animal species, but the initiation sites and the process of neural tube closure are variable among species. Therefore we should be careful when extrapolating the data of normal and abnormal neurulation in laboratory animals to the human. Recent studies in mouse genetics and developmental biology have shown that neural tube defects are quite heterogeneous both etiologically and pathogenetically. Gene mutations responsible for human neural tube defects are largely unknown, but molecular studies of human cases of neural tube defects and their comparison with the mouse genome data should provide a molecular basis for human neural tube defects. [source]

    Landscape Context Moderates Edge Effects: Nesting Success of Wood Thrushes in Central New York

    CONSERVATION BIOLOGY, Issue 5 2004
    MELANIE J. L. DRISCOLL
    We studied abundance and nesting success in Wood Thrushes (Hylocichla mustelina) breeding across a heterogeneous landscape in central New York from 1998 to 2000 to test the hypothesis that edge effects on nesting passerines are stronger in fragmented than contiguous landscapes. We monitored nests to estimate nesting success in edge and interior habitats in both fragmented and contiguously forested landscapes. In contiguous landscapes, daily survival rate did not differ between edge nests (0.963) and interior nests (0.968) (,2= 0.19, p = 0.66). In contrast, in fragmented landscapes, daily survival estimates were higher in interior (0.971) than edge (0.953) nests (,2= 3.1, p = 0.08). Our study supports the hypothesis that landscape composition moderates edge effects on actual nests of birds but does not determine the mechanisms causing these patterns. Resumen:,No obstante dos décadas de investigación sobre fragmentación de hábitat y efecto de borde sobre aves anidantes, aun se carece de información sobre el efecto de borde sobre el éxito de nidos naturales de aves migratorias neotropicales que se reproducen en pasajes heterogéneos. Estudiamos la abundancia y éxito de anidación de Hylocichla mustelina en un paisaje heterogéneo en el centro de New York de 1998 , 2000 para probar la hipótesis de que el efecto de borde sobre paserinas anidantes eran mayores en paisajes fragmentados que en continuos. Monitoreamos nidos para estimar el éxito en hábitats de borde y de interior en paisajes tanto con bosques continuos como discontinuos. En paisajes continuos, la tasa de supervivencia diaria no difirió entre nidos de borde (0.963) y nidos de interior (0.968) (,2= 0.19, p = 0.66). En contraste, en paisajes fragmentados, las estimaciones de supervivencia diaria fueron mayores en nidos del interior (0.971) que del borde (0.953) (,2= 3.1, p = 0.08). Nuestro estudio soporta la hipótesis de que la composición del paisaje modera los efectos de borde sobre nidos de aves, pero no determina los mecanismos que causan estos patrones. [source]

    Heterogeneous Plasma-Producing Structures at Current Implosion of a Wire Array

    CONTRIBUTIONS TO PLASMA PHYSICS, Issue 8 2005
    E. V. Grabovsky
    Abstract Characteristic properties of the plasma production process have been considered for the case of megampere currents flowing through hollow cylindrical wire arrays of the Angara-5-1 facility. In 3-4 nanoseconds after voltage applying to the wire surfaces there appear a plasma layer. The system becomes heterogeneous, i.e. consisting of a kernel of metal wires and a plasma layer. In several nanoseconds the current flow goes from metal to plasma, which results in reducing the electric field strength along the wire. The Joule heat energy delivered to the metal before the moment of complete current trapping by plasma is insufficient for the whole mass transition to a hot plasma state. The X-ray radiography techniques made it possible to detect and study dense clusters of substance of ,1g/cm3 at a developed discharge stage. The radial expansion velocity of ,104 cm/s measured at the 70-th nanosecond after the current start allows treating the dense core at a late stage in the form of a submicron heterogeneous structure from its liquid and slightly ionized gas phase. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

    Situating Global Capitalisms: A View from Wall Street Investment Banks

    CULTURAL ANTHROPOLOGY, Issue 1 2005
    Karen Ho
    The project of conceptualizing powerful subjects and intervening against Wall Street investment banks' hegemonic claims is thwarted by social scientific norms of approaching late capitalism and globalization. Overarching scripts of capitalist globalization not only prevent understanding the heterogeneous and complicated particularities of Wall Street's approaches to the global but also ironically parallel the marketing schemes and hyped representations of Wall Street capitalist promoters. Drawing from in-depth fieldwork with investment bankers, this article portrays Wall Street's uses and understandings of the global and the contingencies and contexts of its global imaginings. It demonstrates that even for the most seemingly globalized and powerful of actors, global ambitions can implode and generate internal contradictions. [source]

    Heterogeneous modes of uptake for latex beads revealed through live cell imaging of phagocytes expressing a probe for phosphatidylinositol-(3,4,5)-trisphosphate and phosphatidylinositol-(3,4)-bisphosphate

    CYTOSKELETON, Issue 9 2008
    Jennifer Giorgione
    Abstract Latex beads are the preferred phagocytic substrate in biochemical studies of phagosome composition and maturation. Using living Dictyostelium cells and fluorescent probes, we compared the properties of phagosomes formed to ingest latex beads or digestible prey. Significant differences were found during the initial steps of phagocytosis. During uptake of bacteria or yeast, PHcrac-GFP, a probe that binds to membranes enriched in PI(3,4,5)P3 and PI(3,4)P2, always labeled the nascent phagosome and faded shortly after it sealed. However, labeling of bead-containing phagosomes was highly variable. Beads were engulfed by phagosomes either lacking or displaying the PHcrac-GFP label, and that label, if present, often persisted for many minutes, revealing that early trafficking steps for bead-containing phagosomes are quite heterogeneous. Later stages of the endocytic pathway appeared more similar for phagosomes containing prey and latex beads. Both types of phagosomes fused with acidic endosomes while undergoing transport along microtubules, both acquired the V-ATPase and lost it prior to exocytosis, and both bound the late endosome marker vacuolin B, which was transferred to the plasma membrane upon exocytosis. We conclude that caution is needed in extrapolating results from latex bead phagosomes to phagosomes containing physiological substances, especially in early stages of the endocytic pathway. Cell Motil. Cytoskeleton 2008. © 2008 Wiley-Liss, Inc. [source]

    Learning How and Learning What: Effects of Tacit and Codified Knowledge on Performance Improvement Following Technology Adoption

    DECISION SCIENCES, Issue 2 2003
    Amy C. Edmondson
    ABSTRACT This paper examines effects of tacit and codified knowledge on performance improvement as organizations gain experience with a new technology. We draw from knowledge management and learning curve research to predict improvement rate heterogeneity across organizations. We first note that the same technology can present opportunities for improvement along more than one dimension, such as efficiency and breadth of use. We compare improvement for two dimensions: one in which the acquisition of codified knowledge leads to improvement and another in which improvement requires tacit knowledge. We hypothesize that improvement rates across organizations will be more heterogeneous for dimensions of performance that rely on tacit knowledge than for those that rely on codified knowledge (H1), and that group membership stability predicts improvement rates for dimensions relying on tacit knowledge (H2). We further hypothesize that when performance relies on codified knowledge, later adopters should improve more quickly than earlier adopters (H3). All three hypotheses are supported in a study of 15 hospitals learning to use a new surgical technology. Implications for theory and practice are discussed. [source]

    Research Methods of Inquiry

    ACADEMIC EMERGENCY MEDICINE, Issue 11 2006
    Joel Rodgers MA
    Incidents of significant consequence that create surge may require special research methods to provide reliable, generalizable results. This report was constructed through a process of literature review, expert panel discussion at the journal's consensus conference, and iterative development. Traditional clinical research methods that are well accepted in medicine are exceptionally difficult to use for surge incidents because the incidents are very difficult to reliably predict, the consequences vary widely, human behaviors are heterogeneous in response to incidents, and temporal conditions prioritize limited resources to response, rather than data collection. Current literature on surge research methods has found some degree of reliability and generalizability in case-control, postincident survey methods, and ethnographical designs. Novel methods that show promise for studying surge include carefully validated simulation experiments and survey methods that produce validated results from representative populations. Methodologists and research scientists should consider quasi-experimental designs and case-control studies in areas with recurrent high-consequence incidents (e.g., earthquakes and hurricanes). Specialists that need to be well represented in areas of research include emergency physicians and critical care physicians, simulation engineers, cost economists, sociobehavioral methodologists, and others. [source]

    Treatment of schizoaffective disorder , a challenge for evidence-based psychiatry

    ACTA PSYCHIATRICA SCANDINAVICA, Issue 1 2010
    M. Jäger
    Objective:, Schizoaffective disorder is a common diagnosis in mental health services. The aim of the present article was to review treatment studies for schizoaffective disorder and draw conclusions for clinical decision making. Method:, We searched MEDLINE and Cochrane Library for relevant clinical trials and review articles up to the year 2008. Results:, Thirty-three studies using standardized diagnostic criteria, 14 of which were randomized controlled trials, could be identified. The comparability of studies is limited by the use of different diagnostic criteria. The studies reviewed do not permit consistent recommendations as to whether schizoaffective disorder should be treated primarily with antipsychotics, mood stabilizers or combinations of these drugs. The relevance of diverse subtypes of schizoaffective disorder for treatment recommendations is unclear. Conclusion:, The pertinent empirical database is small and heterogeneous. The lack of conclusive recommendations is related to issues of nosological status, plurality of diagnostic criteria and validity of the concept of schizoaffective disorder. [source]

    Nestin expression in pancreatic endocrine and exocrine cells of mice lacking glucagon signaling

    DEVELOPMENTAL DYNAMICS, Issue 4 2007
    Mamdouh H. Kedees
    Abstract Nestin, a marker of neural stem cells, is also expressed by cells located in the epithelium of the pancreatic primordium and by a subpopulation of exocrine cells but not by endocrine cells. These findings raised the possibility that the pancreatic epithelium is heterogeneous and comprised of subpopulations of exocrine/nestin-positive and endocrine/nestin-negative precursor cells. We examined this issue in two mutant mouse models characterized by protracted expression of several embryonal properties in islet cells. One mutant line comprises mice lacking mature glucagon due to abrogation of proprotein convertase-2 (PC2,/,), responsible for the conversion of proglucagon into glucagon, while the second line consists of mice with a global deletion of the glucagon receptor (Gcgr,/,). We demonstrate that nestin is transiently expressed by acinar cells and by insulin and glucagon cells of islets of both lines of mice. In addition, the lack of glucagon signaling increased nestin mRNA levels in pancreas of mutant embryos and adult mice. We conclude that nestin+ cells located in the pancreatic primordium generate the cells of the endocrine and exocrine lineages. Furthermore, our results suggest that nestin expression is regulated by glucagon signaling. Developmental Dynamics 236:1126,1133, 2007. © 2007 Wiley-Liss, Inc. [source]

    Changing patterns of ganglion cell coupling and connexin expression during chick retinal development

    DEVELOPMENTAL NEUROBIOLOGY, Issue 4 2002
    David L. Becker
    Abstract We have used dye injection and immunolabeling to investigate the relationship between connexin (Cx) expression and dye coupling between ganglion cells (GCs) and other cells of the embryonic chick retina between embryonic days 5 and 14 (E5,14). At E5, GCs were usually coupled, via soma-somatic or dendro-somatic contacts, to only one or two other cells. Coupling increased with time until E11 when GCs were often coupled to more than a dozen other cells with somata in the ganglion cell layer (GCL) or inner nuclear layer (INL). These coupled clusters occupied large areas of the retina and coupling was via dendro-dendritic contacts. By E14, after the onset of synaptogenesis and at a time of marked cell death, dye coupling was markedly decreased with GCs coupled to three or four partners. At this time, coupling was usually to cells of the same morphology, whereas earlier coupling was heterogeneous. Between E5 and E11, GCs were sometimes coupled to cells of neuroepithelial morphology that spanned the thickness of the retina. The expression of Cx 26, 32, and 43 differed and their distribution changed during the period studied, showing correlation with events such as proliferation, migration, and synaptogenesis. These results suggest specific roles for gap junctions and Cx's during retinal development. © 2002 Wiley Periodicals, Inc. J Neurobiol 52: 280,293, 2002 [source]

    On phenomenology and classification of hoarding: a review

    ACTA PSYCHIATRICA SCANDINAVICA, Issue 5 2004
    T. Maier
    Objective:, Hoarding is a behavioural abnormity characterized by the excessive collection of poorly useable objects. It is described mainly in association with obsessive,compulsive disorders (OCDs) and in geriatric populations. Yet the literature on the phenomenon is heterogeneous and the notion obviously lacks a consistent definition. This review attempts to describe the psychopathological and clinical spectrum of hoarding and may contribute to clarify its classification. Method:, Systematic review and discussion of the literature on hoarding. Results:, Hoarding is a complex behavioural phenomenon associated with different mental disorders. The psychopathological structure is variously composed of elements of OCDs, impulse-control disorders, and ritualistic behaviour. Severe self-neglect is a possible consequence of hoarding. Conclusion:, Without further specifications the term hoarding is of limited heuristic value and cannot guide therapeutic interventions satisfactorily. The condition needs to be evaluated carefully in every particular case in relation to the aforementioned psychopathological concepts. [source]

    Culturally appropriate health education for Type 2 diabetes in ethnic minority groups: a systematic and narrative review of randomized controlled trials

    DIABETIC MEDICINE, Issue 6 2010
    K. Hawthorne
    Diabet. Med. 27, 613,623 (2010) Abstract To determine if culturally appropriate health education is more effective than ,usual' health education for people with diabetes from ethnic minority groups living in high- and upper-middle-income countries. A systematic review with meta-analysis, following the methodology of the Cochrane Collaboration. Electronic literature searches of nine databases were made, with hand searching of three journals and 16 author contacts. The criteria for inclusion into the analysis were randomized controlled trials of a specified diabetes health education intervention, and a named ethnic minority group with Type 2 diabetes. Data were collected on HbA1c, blood pressure, and quality-of-life measures. A narrative review was also performed. Few studies fitted the selection criteria, and were heterogeneous in methodologies and outcome measures, making meta-analysis difficult. HbA1c showed an improvement at 3 months [weighted mean difference (WMD) ,0.32%, 95% confidence interval (CI) ,0.63, ,0.01] and 6 months post intervention (WMD ,0.60%, 95% CI ,0.85, ,0.35). Knowledge scores also improved in the intervention groups at 6 months (standardized mean difference 0.46, 95% CI 0.27, 0.65). There was only one longer-term follow-up study, and one formal cost-effectiveness analysis. Culturally appropriate health education was more effective than ,usual' health education in improving HbA1c and knowledge in the short to medium term. Due to poor standardization between studies, the data did not allow determination of the key elements of interventions across countries, ethnic groups and health systems, or a broad view of their cost-effectiveness. The narrative review identifies learning points to direct future research. [source]