Reveals

Distribution by Scientific Domains
Distribution within Chemistry

Kinds of Reveals

  • analysis reveal
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  • article reveal
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  • cell reveal
  • complex reveal
  • data reveal
  • diffraction reveal
  • electron microscopy reveal
  • evidence reveal
  • experiment reveal
  • finding reveal
  • imaging reveal
  • investigation reveal
  • level reveal
  • literature reveal
  • literature review reveal
  • microscopy reveal
  • model reveal
  • models reveal
  • paper reveal
  • present study reveal
  • regression analysis reveal
  • research reveal
  • result reveal
  • review reveal
  • sequence reveal
  • simulation reveal
  • spectroscopy reveal
  • spectrum reveal
  • structure reveal
  • studies reveal
  • study reveal
  • survey reveal
  • system reveal
  • transmission electron microscopy reveal
  • work reveal

  • Terms modified by Reveals

  • reveal a number
  • reveal difference
  • reveal evidence
  • reveal significant difference

  • Selected Abstracts


    Electromagnetic Interference of an Implantable Loop Recorder by Commonly Encountered Electronic Devices

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 10 2000
    CAREL C. DE COCK
    De COCK, C.C., et al.: Electromagnetic Interference of an Implantable Loop Recorder by Commonly Encountered Electronic Devices. Electromagnetic interference of pacemaker systems has been well established and can lead to an inappropriate function of these devices. Recently, an implantable loop recorder (ILR) (REVEAL, Medtronic Inc.) has been introduced to evaluate the possible arrhythmic etiology of patients with recurrent syncope. We evaluated the interference of this device in two patients with implantable ILR and in three nonimplanted ILRs with four electromagnetic sources: cellular phones (GSMs), electronic article surveillance systems (EASs), metal detector gates (MDGs), and magnetic resonance imaging (MRI). The GSM did not affect appropriate function of the ILR whereas radiofrequency (RF) EAS could interfere with normal function in implanted and nonimplanted systems. The MDG had no influence on ILR function. The magnetic field induced by the MRI resulted in an irreversible error in one nonimplanted ILR. Therefore, although interference between electromagnetic sources and ILRs appears to be rare in our study, physicians should be aware of possible malfunctioning of these devices. [source]


    PATIENTS ARE A VIRTUE: WHAT STUDIES OF CLINICAL AND NEUROLOGICAL PATIENTS REVEAL ABOUT PHYSIOLOGICAL MECHANISMS OF EMOTION

    PSYCHOPHYSIOLOGY, Issue 2008
    Article first published online: 12 AUG 200
    No abstract is available for this article. [source]


    POPULATION STRUCTURE IN AN INSHORE CETACEAN REVEALED BY MICROSATELLITE AND mtDNA ANALYSIS: BOTTLENOSE DOLPHINS (TURSIOPS SP.) IN SHARK BAY, WESTERN AUSTRALIA

    MARINE MAMMAL SCIENCE, Issue 1 2004
    Michael Krützen
    Abstract We examined population substructure of bottlenose dolphins (Tursiops sp). in Shark Bay, Western Australia, using 10 highly polymorphic microsatellite loci, and mitochondrial DNA (mtDNA). For microsatellite analysis, 302 different animals were sampled from seven localities throughout the bay. Analysis of genetic differentiation between sampling localities showed a significant correlation between the number of migrants (Nm) calculated from FST, RST and private alleles, and distance between localities,a pattern of isolation-by-distance. For mtDNA, 220 individuals from all seven localities were sequenced for a 351 base pair fragment of the control region, resulting in eight haplotypes, with two distinct clusters of haplotypes. Values of FST and (,)ST for mtDNA yielded statistically significant differences, mostly between localities that were not adjacent to each other, suggesting female gene flow over a scale larger than the sampled localities. We also observed a significant correlation between the number of female migrants calculated from FST and ,ST and the distance of sampling localities. Our results indicate that dispersal in female dolphins in Shark Bay is more restricted than that of males. [source]


    WHEN ONTOGENY REVEALS WHAT PHYLOGENY HIDES: GAIN AND LOSS OF HORNS DURING DEVELOPMENT AND EVOLUTION OF HORNED BEETLES

    EVOLUTION, Issue 11 2006
    Armin P. Moczek
    Abstract How ecological, developmental and genetic mechanisms interact in the genesis and subsequent diversification of morphological novelties is unknown for the vast majority of traits and organisms. Here we explore the ecological, developmental, and genetic underpinnings of a class of traits that is both novel and highly diverse: beetle horns. Specifically, we focus on the origin and diversification of a particular horn type, those protruding from the pronotum, in the genus Onthophagus, a particularly speciose and morphologically diverse genus of horned beetles. We begin by documenting immature development of nine Onthophagus species and show that all of these species express pronotal horns in a developmentally transient fashion in at least one or both sexes. Similar to species that retain their horns to adulthood, transient horns grow during late larval development and are clearly visible in pupae. However, unlike species that express horns as adults, transient horns are resorbed during pupal development. In a large number of species this mechanisms allows fully horned pupae to molt into entirely hornless adults. Consequently, far more Onthophagus species appear to possess the ability to develop pronotal horns than is indicated by their adult phenotypes. We use our data to expand a recent phylogeny of the genus Onthophagus to explore how the widespread existence of developmentally transient horns alters our understanding of the origin and dynamics of morphological innovation and diversification in this genus. We find that including transient horn development into the phylogeny dramatically reduces the number of independent origins required to explain extant diversity patters and suggest that pronotal horns may have originated only a few times, or possibly only once, during early Onthophagus evolution. We then propose a new and previously undescribed function for pronotal horns during immature development. We provide histological as well as experimental data that illustrate that pronotal horns are crucial for successful ecdysis of the larval head capsule during the larval-to-pupal molt, and that this molting function appears to be unique to the genus Onthophagus and absent in the other scarabaeine genera. We discuss how this additional function may help explain the existence and maintenance of developmentally transient horns, and how at least some horn types of adult beetles may have evolved as exaptations from pupal structures originally evolved to perform an unrelated function. [source]


    What does Monetary Policy Reveal about a Central Bank's Preferences?

    ECONOMIC NOTES, Issue 3 2003
    Efrem Castelnuovo
    The design of monetary policy depends on the targeting strategy adopted by the central bank. This strategy describes a set of policy preferences, which are actually the structural parameters to analyse monetary policy making. Accordingly, we develop a calibration method to estimate a central bank's preferences from the estimates of an optimal Taylor,type rule. The empirical analysis on US data shows that output stabilization has not been an independent argument in the Fed's objective function during the Greenspan's era. This suggests that the output gap has entered the policy rule only as leading indicator for future inflation, therefore being only instrumental (to stabilize inflation) rather than important per se. (J.E.L.: C61, E52, E58). [source]


    Two Varieties of Conditionals and Two Kinds of Defeaters Help Reveal Two Fundamental Types of Reasoning

    MIND & LANGUAGE, Issue 4 2006
    POLITZER GUY
    The distinction between disabling conditions and alternative causes is shown to be a special case of Pollock's (1987) distinction between ,rebutting' and ,undercutting' defeaters. ,Inferential' conditionals are shown to come in two varieties, one that is sensitive to rebutters, the other to undercutters. It is thus predicted and demonstrated in two experiments that the type of inferential conditional used as the major premise of conditional arguments can reverse the heretofore classic, distinctive effects of defeaters. [source]


    Spontaneous Resolution of Racemic Hydrogen-Bonded Nanoassemblies on Graphite Revealed by Atomic Force Microscopy,

    ADVANCED MATERIALS, Issue 16 2004
    H. Schönherr
    An atomic force microscopy (AFM) investigation into the spontaneous resolution of a P/M racemic mixture of helical self-assembled tetrarosettes 13·(DEB)12 (see Figure) into enantiopure domains in 2D supramolecular assemblies on highly oriented pyrolytic graphite (HOPG) is reported. These results represent the first reported case of spontaneous resolution of a racemate of chiral nanostructures. [source]


    Differential Increase in Taurine Levels by Low-Dose Ethanol in the Dorsal and Ventral Striatum Revealed by Microdialysis With On-Line Capillary Electrophoresis

    ALCOHOLISM, Issue 7 2004
    A Smith
    Ethanol increases taurine efflux in the nucleus accumbens or ventral striatum (VS), a dopaminergic terminal region involved in positive reinforcement. However, this has been found only at ethanol doses above 1 g/kg intraperitoneally, which is higher than what most rats will self-administer. We used a sensitive on-line assay of microdialysate content to test whether lower doses of ethanol selectively increase taurine efflux in VS as opposed to other dopaminergic regions not involved in reinforcement (e.g., dorsal striatum; DS). Adult male rats with microdialysis probes in VS or DS were injected with ethanol (0, 0.5, 1, and 2 g/kg intraperitoneally), and the amino acid content of the dialysate was measured every 11 sec using capillary electrophoresis and laser-induced fluorescence detection. In VS, 0.5 g/kg ethanol significantly increased taurine levels by 20% for 10 min. A similar increase was seen after 1 g/kg ethanol, which lasted for about 20 min after injection. A two-phased taurine efflux was observed with the 2.0 g/kg dose, where taurine was increased by 2-fold after 5 min but it remained elevated by 30% for at least 60 min. In contrast, DS exhibited much smaller dose-related increases in taurine. Glycine, glutamate, serine, and ,-aminobutyric acid were not systematically affected by lower doses of ethanol; however, 2 g/kg slowly decreased these amino acids in both brain regions during the hour after injection. These data implicate a possible role of taurine in the mechanism of action of ethanol in the VS. The high sensitivity and time resolution afforded by capillary electrophoresis and laser-induced fluorescence detection will be useful for detecting subtle changes of neuronally active amino acids levels due to low doses of ethanol. [source]


    Insights into Multienzyme Docking in Hybrid PKS,NRPS Megasynthetases Revealed by Heterologous Expression and Genetic Engineering

    CHEMBIOCHEM, Issue 8 2010
    Yanyan Li
    A critical test: We have used Red/ET recombination in a heterologous expression vector to site-specifically modify the pathway to the myxobacterial metabolite myxothiazol. Our mutagenesis results strengthen an existing model for interpolypeptide "docking" during biosynthesis of such hybrid polyketide,nonribosomal peptide natural products. [source]


    Silver Ion Dynamics in the Ag5Te2Cl-Polymorphs Revealed by Solid State NMR Lineshape and Two- and Three-Time Correlation Spectroscopies.

    CHEMINFORM, Issue 13 2006
    Christian Brinkmann
    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]


    The Nature of Oxygen Exchange in ZrW2O8 Revealed by Two-Dimensional Solid-State 17O NMR.

    CHEMINFORM, Issue 18 2004
    Matthew R. Hampson
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]


    The Choice of Standardisation Reveals a Significant Influence on the Dynamics of Bacterial Abundance in Newly Deposited River Sediments

    INTERNATIONAL REVIEW OF HYDROBIOLOGY, Issue 3-4 2003
    Andreas H. Farnleitner
    Abstract After a high water event of the River Danube in April 1994, bacterial cell numbers were determined in newly formed deposits in a backwater near Hainburg (Lower Austria) within a time course of 140 days. This data set shows that expressing bacterial numbers per fresh sediment volume, per sediment dry mass, or per pore-water fluid volume, respectively, yield significantly different results and ecological conlusions. These findings refer particularly to intra-study and time-course comparisons as presented in our case. Bacterial cell numbers expressed per gram sediment dry mass revealed statistically significant differences between the beginning and the end of the study, whereas expressed per cm3 of fresh sediment or fluid volume of sediment pore water, no statistical difference could be detected. It is argued that these differences were caused by physical sediment compaction and mineralisation processes over the considered time-course. Such mechanisms may simulate biological activity if some basic sediment parameters are neglected and thus standardisation has to be done with caution for the particular situation being observed. [source]


    Genome-wide Characterization of Long Terminal Repeat -retrotransposons in Apple Reveals the Differences in Heterogeneity and Copy Number between Ty1 -copia and Ty3 -gypsy Retrotransposons

    JOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 9 2008
    Hai-Yue Sun
    Abstract The conserved domains of reverse transcriptase (RT) genes of Ty1- copia and Ty3- gypsy groups of long terminal repeat (LTR) retrotransposons were isolated from the Malus domestica genome using degenerate oligonucleotide primers. Sequence analysis showed that 45% of Ty1- copia and 63% of Ty3- gypsy RT sequences contained premature stop codons and/or indels disrupting the reading frame. High heterogeneity among RT sequences of both Ty1- copia and Ty3- gypsy group retrotransposons was observed, but Ty3- gypsy group retrotransposons in the apple genome are less heterogeneous than Ty1- copia elements. Retrotransposon copy number was estimated by dot blot hybridizations for Ty1- copia (,5 000) and Ty3- gypsy (,26 000). All elements of the two types of LTR retrotransposons comprise approximately 38% of the M. domestica genome, with the Ty3- gypsy group contribution being higher (33.5%) than the Ty1- copia one (4.6%). Transcription was not detected by reverse transcription-polymerase chain reaction for either Ty1- copia or Ty3- gypsy retrotransposons in the leaves of plants in vitro or in leaf explants cultured on medium supplemented with high concentration benzylaminopurine. This research reveals the differences in heterogeneity and copy number between Ty1- copia and Ty3- gypsy retrotransposons in the apple genome. Ty1- copia retrotransposon has higher heterogeneity than Ty3- gypsy retrotransposon, but the latter has a higher copy number, which implies that Ty3- gypsy retrotransposons may play a more important role in the apple genome evolution. [source]


    An Assay for Evoked Locomotor Behavior in Drosophila Reveals a Role for Integrins in Ethanol Sensitivity and Rapid Ethanol Tolerance

    ALCOHOLISM, Issue 10 2009
    Poonam Bhandari
    Background:, Ethanol induces similar behavioral responses in mammals and the fruit fly, Drosophila melanogaster. By coupling assays for ethanol-related behavior to the genetic tools available in flies, a number of genes have been identified that influence physiological responses to ethanol. To enhance the utility of the Drosophila model for investigating genes involved in ethanol-related behavior, we explored the value of an assay that measures the sedative effects of ethanol on negative geotaxis, an evoked locomotor response. Methods:, We established eRING (ethanol Rapid Iterative Negative Geotaxis) as an assay for quantitating the sedative effects of ethanol on negative geotaxis (i.e., startle-induced climbing). We validated the assay by assessing acute sensitivity to ethanol and rapid ethanol tolerance in several different control strains and in flies with mutations known to disrupt these behaviors. We also used eRING in a candidate screen to identify mutants with altered ethanol-related behaviors. Results:, Negative geotaxis measured in eRING assays was dose-dependently impaired by ethanol exposure. Flies developed tolerance to the intoxicating effects of ethanol when tested during a second exposure. Ethanol sensitivity and rapid ethanol tolerance varied across 4 control strains, but internal ethanol concentrations were indistinguishable in the 4 strains during a first and second challenge with ethanol. Ethanol sensitivity and rapid ethanol tolerance, respectively, were altered in flies with mutations in amnesiac and hangover, genes known to influence these traits. Additionally, mutations in the , integrin gene myospheroid and the , integrin gene scab increased the initial sensitivity to ethanol and enhanced the development of rapid ethanol tolerance without altering internal ethanol concentrations. Conclusions:, The eRING assay is suitable for investigating genetic mechanisms that influence ethanol sensitivity and rapid ethanol tolerance. Ethanol sensitivity and rapid ethanol tolerance depend on the function of , and , integrins in flies. [source]


    Pulse EPR Spectroscopy Reveals the Coordination Sphere of Copper(II) Ions in the 1,16 Amyloid-, Peptide: A Key Role of the First Two N-Terminus Residues,

    ANGEWANDTE CHEMIE, Issue 49 2009
    Pierre Dorlet Dr.
    Ligandensphäre aufgedeckt: Cu-Ionen sollen an der Aggregation des Amyloid-,-Peptids bei Alzheimer beteiligt sein, die eindeutige Identifizierung der Cu-Liganden ist jedoch schwierig. Mit EPR- und Isotopenmarkierungstechniken wurden nun die CuII -Liganden der beiden Komplexe, die bei physiologischen pH-Werten vorliegen, ermittelt (siehe Diagramme und Strukturen). Die ersten beiden Aminosäuren des Peptids sind für die Koordination und wahrscheinlich die Aggregation wichtig. [source]


    Cross-Linking of Transmembrane Helices Reveals a Rigid-Body Mechanism in Bacteriorhodopsin Transport,

    ANGEWANDTE CHEMIE, Issue 45 2009
    Rosana Simón-Vázquez Dr.
    Die blitzinduzierte kurzlebige Protonierung von Pyranin wurde in Gegenwart der vernetzten Doppelmutante E166C/A228C (rote Spur), einer reduzierten Mutante (blaue Spur) und eines Wildtyp-Bacteriorhodopsins (graue Spuren) untersucht. Wenn zwei Helices F und G vernetzt sind, kommt es zu einer Verzögerung der Protonenabgabe (extrazelluläre Seite) und Protonenaufnahme (cytoplasmatische Seite). Zusammen mit Blitzphotolyse- und FTIR-Studien besagen diese Daten, dass der Protonentransport im Bacteriorhodopsin über einen Starrkörper-Mechanismus verläuft. [source]


    The Crystal Structure of an [Fe]-Hydrogenase,Substrate Complex Reveals the Framework for H2 Activation,

    ANGEWANDTE CHEMIE, Issue 35 2009
    Takeshi Hiromoto Dr.
    Die Struktur eines binären Komplexes aus C176A-[Fe]-Hydrogenase und Methylentetrahydromethanopterin in einer offenen Konformation wurde mit einer Auflösung von 2.15,Å aufgeklärt, und eine geschlossene Form des Komplexes wurde auf der Grundlage der experimentell erhaltenen Struktur modelliert. In diesem Modell befindet sich das Eisenzentrum in trans -Stellung zum Acylkohlenstoffatom neben C14a, sodass es als H2 bindende Stelle angesehen wird. [source]


    A Genome-wide Association Study of Autism Reveals a Common Novel Risk Locus at 5p14.1

    ANNALS OF HUMAN GENETICS, Issue 3 2009
    Deqiong Ma
    Summary Although autism is one of the most heritable neuropsychiatric disorders, its underlying genetic architecture has largely eluded description. To comprehensively examine the hypothesis that common variation is important in autism, we performed a genome-wide association study (GWAS) using a discovery dataset of 438 autistic Caucasian families and the Illumina Human 1M beadchip. 96 single nucleotide polymorphisms (SNPs) demonstrated strong association with autism risk (p-value < 0.0001). The validation of the top 96 SNPs was performed using an independent dataset of 487 Caucasian autism families genotyped on the 550K Illumina BeadChip. A novel region on chromosome 5p14.1 showed significance in both the discovery and validation datasets. Joint analysis of all SNPs in this region identified 8 SNPs having improved p-values (3.24E-04 to 3.40E-06) than in either dataset alone. Our findings demonstrate that in addition to multiple rare variations, part of the complex genetic architecture of autism involves common variation. [source]


    Mapping the Conservation Landscape

    CONSERVATION BIOLOGY, Issue 1 2003
    Kent H. Redford
    To begin this process and to help build understanding and collaboration, we provide a conceptual map of 21 approaches currently being implemented by 13 conservation organizations. We examined each of these approaches according to (1) the nature of the conservation target,the object(s) of the conservation action; ( 2 ) whether the question addressed is where conservation should be done or how conservation should be done; ( 3 ) the scale ( both grain and extent ) of the approach; and (4 ) the principles that underlie the approach. These questions provide a good way of distinguishing between most of the approaches and reveal that there is less competition between them than is assumed. We conclude that only with explicit understanding can the conservation community and its supporters critically compare approaches and come to a consensus about a set of metrics for measuring and achieving global conservation. Resumen: Para que una colaboración bien fundamentada pueda llevarse a cabo, debe haber un proceso de entendimiento de los distintos enfoques utilizadas por diferentes organizaciones de conservación para preservar la biodiversidad. Para iniciar este proceso y ayudar a fomentar el conocimiento y la colaboración, proveemos un mapa conceptual de 21 enfoques utilizados actualmente por 13 organizaciones conservacionistas. Examinamos cada uno de estos enfoques según (1) la naturaleza del objetivo de conservación,el ( los ) objetos( s ) de las actividades de conservación; ( 2 ) la naturaleza de la pregunta a contestar, ya sea "dónde se debe llevar a cabo la conservación" o "cómo se debe llevar a cabo la conservación"; ( 3 ) la escala ( tanto a nivel de detalle como extensión ) del enfoque; (4 ) los principios que constituyen el fundamento del enfoque. Estas preguntas proveen una buena manera de diferenciar la mayoría de las metodologías y muestran que hay menos competencia entre los enfoques de lo que se cree. Concluimos que la comunidad conservacionista y sus seguidores solo podrán comparar los diversos enfoques de manera criteriosa si tienen un entendimiento explícito de los mismos, y de esa manera, podrá desarrollar, por consenso, una serie de variables para medir y lograr la conservación a nivel global. [source]


    Sonochemical synthesis and characterization of ZnO nanorod/Ag nanoparticle composites

    CRYSTAL RESEARCH AND TECHNOLOGY, Issue 11 2009
    Fei Li
    Abstract A simple sonochemical route for the synthesis of Ag nanoparticles on ZnO nanorods is reported. Ultrasonic irradiation of a mixture of ZnO nanorods, Ag(NH3)2+, and formaldehyde in an aqueous medium yields ZnO nanorod/Ag nanoparticle composites. The powder X-ray diffraction of the ZnO/Ag composites shows additional diffraction peaks corresponding to the face-center-cubic structured Ag crystalline, apart from the signals from the ZnO nanorods. Scanning electron microscopy and transmission electron microscopy images of the ZnO/Ag composites reveal that the ZnO nanorods are coated with Ag nanoparticles with a mean size of several tens nanometer. The absorption band of ZnO/Ag composites is distinctly broadened and red-shifted, indicating the strong interfacial interaction between ZnO nanorods and Ag nanoparticles. This sonochemical method is simple, mild and readily scaled up, affording a simple way for synthesis of other composites. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Growth and characterization of pure and doped nonlinear optical l-arginine acetate single crystals

    CRYSTAL RESEARCH AND TECHNOLOGY, Issue 10 2007
    M. Gulam Mohamed
    Abstract Single crystals of organic nonlinear optical material of pure, Cu2+ and Mg2+ doped L-arginine acetate (LAA) were successfully grown by slow evaporation method at room temperature. The UV-Vis-NIR spectra of pure and doped LAA indicate that these crystals possess a wide optical transmission window from 240-1600 nm. Non-linear optical studies reveal that the SHG efficiency of LAA is nearly three times that of KDP. The dielectric response of the samples was studied in the frequency region 100 Hz to 2 MHz and the influence of Cu2+ and Mg2+ substitution on the dielectric behaviour had been investigated. Photoconductivity study proves that both pure and Cu2+ and Mg2+ doped LAA crystal exhibit positive photoconductivity. It is evident from the Vickers hardness study that the hardness of the crystal decreases with increasing load both for pure and doped samples. ESR studies confirmed the incorporation of Cu2+ into LAA and the value of g-factor was found to be 2.1654. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    The influence of metallic substitution on the physical properties of manganese mercury thiyocyanate crystals

    CRYSTAL RESEARCH AND TECHNOLOGY, Issue 3 2007
    G. P. Joseph
    Abstract Good optical grade single crystals of pure, Cd2+ and Mg2+ doped Manganese Mercury Thiyocyanate (MMTC) crystals are grown by slow solvent evaporation technique at room temperature. Single crystal XRD studies reveal that the incorporation of metallic dopants has not changed the structure of the parent crystal. The SHG efficiencies of the pure and doped samples of MMTC are measured by Kurtz Perry powder method and the results are compared with urea. It is evident from microhardness study that the presence of dopants has increased the mechanical strength of MMTC crystal. The TG/DTG studies confirm that the thermal decomposition temperatures of pure (353°C), Mg2+ doped (363°C) and Cd2+ doped (365°C) MMTC are relatively high when compared to other NLO crystals of the same family. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    The Right Stuff in the Right Place: The Institution of Contemporary Art

    CURATOR THE MUSEUM JOURNAL, Issue 1 2007
    Ian Wedde
    What does our ramble reveal about the institution of contemporary art? "Diversity" hardly seems an adequate word. [source]


    Plant profilin isovariants are distinctly regulated in vegetative and reproductive tissues

    CYTOSKELETON, Issue 1 2002
    Muthugapatti K. Kandasamy
    Abstract Profilin is a low-molecular weight, actin monomer-binding protein that regulates the organization of actin cytoskeleton in eukaryotes, including higher plants. Unlike the simple human or yeast systems, the model plant Arabidopsis has an ancient and highly divergent multi-gene family encoding five distinct profilin isovariants. Here we compare and characterize the regulation of these profilins in different organs and during microspore development using isovariant-specific monoclonal antibodies. We show that PRF1, PRF2, and PRF3 are constitutive, being strongly expressed in all vegetative tissues at various stages of development. These profilin isovariants are also predominant in ovules and microspores at the early stages of microsporogenesis. In contrast, PRF4 and PRF5 are late pollen-specific and are not detectable in other cell types of the plant body including microspores and root hairs. Immunocytochemical studies at the subcellular level reveal that both the constitutive and pollen-specific profilins are abundant in the cytoplasm. In vegetative cell types, such as root apical cells, profilins showed localization to nuclei in addition to the cytoplasmic staining. The functional diversity of profilin isovariants is discussed in light of their spatio-temporal regulation during vegetative development, pollen maturation, and pollen tube growth. Cell Motil. Cytoskeleton 52:22,32, 2002. © 2002 Wiley-Liss, Inc. [source]


    Supply Chain Strategy, Product Characteristics, and Performance Impact: Evidence from Chinese Manufacturers,

    DECISION SCIENCES, Issue 4 2009
    Yinan Qi
    ABSTRACT Supply chain management has become one of the most popular approaches to enhance the global competitiveness of business corporations today. Firms must have clear strategic thinking in order to effectively organize such complicated activities, resources, communications, and processes. An emerging body of literature offers a framework that identifies three kinds of supply chain strategies: lean strategy, agile strategy, and lean/agile strategy based on in-depth case studies. Extant research also suggests that supply chain strategies must be matched with product characteristics in order for firms to achieve better performance. This article investigates supply chain strategies and empirically tests the supply chain strategy model that posits lean, agile, and lean/agile approaches using data collected from 604 manufacturing firms in China. Cluster analyses of the data indicate that Chinese firms are adopting a variation of lean, agile, and lean/agile supply chain strategies identified in the western literature. However, the data reveal that some firms have a traditional strategy that does not emphasize either lean or agile principles. These firms perform worse than firms that have a strategy focused on lean, agile, or lean/agile supply chain. The strategies are examined with respect to product characteristics and financial and operational performance. The article makes significant contributions to the supply chain management literature by examining the supply chain strategies used by Chinese firms. In addition, this work empirically tests the applicability of supply chain strategy models that have not been rigorously tested empirically or in the fast-growing Chinese economy. [source]


    De Novo Malignant Eccrine Spiradenoma with an Interesting and Unusual Location

    DERMATOLOGIC SURGERY, Issue 4 2001
    Serkan Yildirim MD
    Background. Reports in the literature reveal that malignant eccrine spiradenomas (MES) are exceedingly rare, and represent aggressive tumors arising in long-standing benign eccrine spiradenomas (ES). Objective. We present a de novo case of MES of the nose, in contrast to reports in the literature of progression from long-standing benign lesions. Methods. Case report and brief review of the literature. Results. Our case was accepted as de novo MES because there was no evidence of ES on pathologic examination. It was treated by surgical excision with 1 cm tumor-free margins. No recurrence or complications were observed for 2 months, but long-term follow-up could not be performed because the patient died of adenocarcinoma of the colon. Conclusion. Although previously reported lesions have arisen in long-standing benign ESs, usually on the trunk or extremities, this report shows that MES may occur as a primary malignant tumor and may occur in unusual locations such as the nose. [source]


    Integrating Poverty and Environmental Concerns into Value-Chain Analysis: A Conceptual Framework

    DEVELOPMENT POLICY REVIEW, Issue 2 2010
    Simon Bolwig
    Many policy prescriptions emphasise poverty reduction through closer integration of poor people or areas with global markets. Global value chain (GVC) studies reveal how firms and farms in developing countries are upgraded by being integrated in global markets, but few explicitly document the impact on poverty, gender and the environment, or conversely, how value chain restructuring is in turn mediated by local history, social relations and environmental factors. This article develops a conceptual framework that can help overcome the shortcomings in ,standalone' value-chain, livelihood and environmental analyses by integrating the ,vertical' and ,horizontal' aspects of value chains that together affect poverty and sustainability. [source]


    Divergent roles of the DEAD-box protein BS-PL10, the urochordate homologue of human DDX3 and DDX3Y proteins, in colony astogeny and ontogeny

    DEVELOPMENTAL DYNAMICS, Issue 6 2006
    Amalia Rosner
    Abstract Proteins of the highly conserved PL-10 (Ded1P) subfamily of DEAD-box family, participate in a wide variety of biological functions. However, the entire spectrum of their functions in both vertebrates and invertebrates is still unknown. Here, we isolated the Botryllus schlosseri (Urochordata) homologue, BS-PL10, revealing its distributions and functions in ontogeny and colony astogeny. In botryllid ascidians, the colony grows by increasing the number of modular units (each called a zooid) through a whole colony synchronized and weekly cyclical astogenic budding process (blastogenesis). At the level of the colony, both BS-PL10 mRNA and its protein (78 kDa) fluctuate in a weekly pattern that corresponds with the animal's blastogenic cycle, increasing from blastogenic stage A to blastogenic stage D. At the organ/module level, a sharp decline is revealed. Primary and secondary developing buds express high levels of BS-PL10 mRNA and protein at all blastogeneic stages. These levels are reduced four to nine times in the new set of functional zooids. This portrait of colony astogeny differed from its ontogeny. Oocytes and sperm cells express high levels of BS-PL10 protein only at early stages of development. Young embryos reveal background levels with increased expressions in some organs at more developed stages. Results reveal that higher levels of BS-PL10 mRNA and protein are characteristic to multipotent soma and germ cells, but patterns deviate between two populations of differentiating stem cells, the stem cells involved in weekly blastogenesis and stem cells involved in embryogenesis. Two types of experimental manipulations, zooidectomy and siRNA assays, have confirmed the importance of BS-PL10 for cell differentiation and organogenesis. BS-PL10 (phylogenetically matching the animal's position in the evolutionary tree), is the only member of this subfamily in B. schlosseri, featuring a wide range of biological activities, some of which represent pivotal roles. The surprising weekly cyclical expression and the participation in cell differentiation posit this molecule as a model system for studying PL10 protein subfamily. Developmental Dynamics 235:1508,1521, 2006. © 2006 Wiley-Liss, Inc. [source]


    Polysialic acid controls NCAM-induced differentiation of neuronal precursors into calretinin-positive olfactory bulb interneurons

    DEVELOPMENTAL NEUROBIOLOGY, Issue 9 2008
    Iris Röckle
    Abstract Understanding the mechanisms that regulate neurogenesis is a prerequisite for brain repair approaches based on neuronal precursor cells. One important regulator of postnatal neurogenesis is polysialic acid (polySia), a post-translational modification of the neural cell adhesion molecule NCAM. In the present study, we investigated the role of polySia in differentiation of neuronal precursors isolated from the subventricular zone of early postnatal mice. Removal of polySia promoted neurite induction and selectively enhanced maturation into a calretinin-positive phenotype. Expression of calbindin and Pax6, indicative for other lineages of olfactory bulb interneurons, were not affected. A decrease in the number of TUNEL-positive cells indicated that cell survival was slightly improved by removing polySia. Time lapse imaging revealed the absence of chain migration and low cell motility, in the presence and absence of polySia. The changes in survival and differentiation, therefore, could be dissected from the well-known function of polySia as a promoter of precursor migration. The differentiation response was mimicked by exposure of cells to soluble or substrate-bound NCAM and prevented by the C3d-peptide, a synthetic ligand blocking NCAM interactions. Moreover, a higher degree of differentiation was observed in cultures from polysialyltransferase-depleted mice and after NCAM exposure of precursors from NCAM-knockout mice demonstrating that the NCAM function is mediated via heterophilic binding partners. In conclusion, these data reveal that polySia controls instructive NCAM signals, which direct the differentiation of subventricular zone-derived precursors towards the calretinin-positive phenotype of olfactory bulb interneurons. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008 [source]


    Phosphatidylinositol-3-OH kinase regulatory subunits are differentially expressed during development of the rat cerebellum

    DEVELOPMENTAL NEUROBIOLOGY, Issue 1 2001
    José L. Trejo
    Abstract Recent evidence implicates a central role for PI3K signalling in mediating cell survival during the process of neuronal differentiation. Although PI3K activity is stimulated by a wide range of growth factors and cytokines in different cell lines and tissues, activation of this pathway by insulin-like growth factor I (IGF-I) most likely represents the main survival signal during neuronal differentiation. IGF-I is highly expressed during development of the central nervous system, and thus is a critical factor for the development and maturation of the cerebellum. Upon ligand binding, the IGF-I receptor phosphorylates tyrosine residues in SHC and insulin receptor substrates (IRSs) initiating two main signalling cascades, the MAP kinase and the phosphatidylinositol 3-kinase (PI3K) pathways. Activated PI3K is composed of a catalytic subunit (p110, or ,) associated with one of a large family of regulatory subunits (p85,, p85,, p55,, p55,, and p50,). To evaluate the contributions of these various regulatory subunits to neuronal differentiation, we have used antibodies specific for each of the PI3K subunits. Using these antisera, we now demonstrate that PI3K subunits are differentially regulated in cerebellar development, and that the expression level of the p55, regulatory subunit reaches a maximum during postnatal development, decreasing thereafter to low levels in the adult cerebellum. Furthermore, our studies reveal that the distribution of the various PI3K regulatory subunits varies during development of the cerebellum. Interestingly, p55, is expressed in both glial and neuronal cells; moreover, in Purkinje neurones, this subunit colocalises with the IGF-IR. © 2001 John Wiley & Sons, Inc. J Neurobiol 47: 39,50, 2001 [source]