15 research outputs found

    Search for jet extinction in the inclusive jet-pT spectrum from proton-proton collisions at s=8 TeV

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    Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published articles title, journal citation, and DOI.The first search at the LHC for the extinction of QCD jet production is presented, using data collected with the CMS detector corresponding to an integrated luminosity of 10.7  fb−1 of proton-proton collisions at a center-of-mass energy of 8 TeV. The extinction model studied in this analysis is motivated by the search for signatures of strong gravity at the TeV scale (terascale gravity) and assumes the existence of string couplings in the strong-coupling limit. In this limit, the string model predicts the suppression of all high-transverse-momentum standard model processes, including jet production, beyond a certain energy scale. To test this prediction, the measured transverse-momentum spectrum is compared to the theoretical prediction of the standard model. No significant deficit of events is found at high transverse momentum. A 95% confidence level lower limit of 3.3 TeV is set on the extinction mass scale

    Searches for electroweak neutralino and chargino production in channels with Higgs, Z, and W bosons in pp collisions at 8 TeV

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    Searches for supersymmetry (SUSY) are presented based on the electroweak pair production of neutralinos and charginos, leading to decay channels with Higgs, Z, and W bosons and undetected lightest SUSY particles (LSPs). The data sample corresponds to an integrated luminosity of about 19.5 fb(-1) of proton-proton collisions at a center-of-mass energy of 8 TeV collected in 2012 with the CMS detector at the LHC. The main emphasis is neutralino pair production in which each neutralino decays either to a Higgs boson (h) and an LSP or to a Z boson and an LSP, leading to hh, hZ, and ZZ states with missing transverse energy (E-T(miss)). A second aspect is chargino-neutralino pair production, leading to hW states with E-T(miss). The decays of a Higgs boson to a bottom-quark pair, to a photon pair, and to final states with leptons are considered in conjunction with hadronic and leptonic decay modes of the Z and W bosons. No evidence is found for supersymmetric particles, and 95% confidence level upper limits are evaluated for the respective pair production cross sections and for neutralino and chargino mass values

    Local linkages and their effects on headquarters' use of process controls

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    This paper explores the relationship between subsidiaries' local linkages and headquarters' use of process controls. Making use of both agency and network theories, we conceptualize subsidiaries as agents within multinational networks, as well as instruments seeking resources from external networks. In accordance with agency theory, we predict that subsidiaries' use of local linkages will result in a decrease in the use of process controls by headquarters. Empirical results from 407 Taiwanese firms confirm this hypothesis, suggesting that headquarters employing process controls to monitor subsidiaries' linkages with local actors (i.e., local firms) is too costly. Headquarters' use of process controls decreases when a subsidiary is a joint venture, and as the firm accumulates experience in a host market. (C) 2006 Elsevier Inc. All rights reserved

    Benefiting from networks by occupying central positions: An empirical study of the Taiwan health care industry

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    At issue is whether network resources imply some resources available to all members in networks or available only to those occupying structurally central positions in networks. In this article, two conceptual models, the additive and interaction models of the firm, are empirically tested regarding the impact of hospital resources, network resources, and centrality on hospital performance in the Taiwan health care industry. The results demonstrate that: (1) in the additive model, hospital resources and centrality independently affect performance, whereas network resources do not; and (2) no evidence supports the interaction effect of centrality and resources on performance. Based on our findings in Taiwanese practices, the extent to which the resources are acquired externally from networks, we suggest that while adopting interorganizational strategies, hospitals should clearly identify those important resources that reside in-house and those transferred from network partners. How hospitals access resources from central positions is more important than what network resources can hospitals acquire from networks. Hospitals should improve performance by exploiting its in-house resources rather than obtaining network resources externally. In addition, hospitals should not only invest in hospital resources for better performance but should also move to central positions in networks to benefit from collaborations

    Subsidiary size, internationalization, product diversification, and performance in an emerging market

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    Purpose - This study aims to explore subsidiaries' diversification strategies, both internationally and with regard to their product offerings. The study seeks to examine, at the subsidiary level, the relationships between subsidiary size, internationalization, production diversification, and performance. Design/methodology/approach - Based on the archival data of an officially conducted survey, the study used ordered logit regression analysis to test its hypotheses using data from 920 Taiwanese subsidiaries in China. Findings - The study's results revealed: larger subsidiaries tend to engage in internationalization and product diversification activities to a greater degree, and, as a result, tend to exhibit superior performance; and subsidiaries that pursue outward internationalization and that reinvest in related businesses enjoy enhanced performance. Research limitations/implications - This study examines Taiwanese firms that have one foreign subsidiary in China. Future research should examine larger firms with numerous foreign subsidiaries in developed countries, and should employ more fine-grained measurements of subsidiary size to provide a clearer picture of subsidiary-specific advantages. Originality/value - Unlike the existing literature, which has tended to take the perspective of the multinational corporation, this study examines internationalization and product diversification at the subsidiary level. By extending the resource-based view to the subsidiary level, larger subsidiaries might be able to exploit their advantages so as to more successfully implement international and product diversification strategies and improve their performance in a host country

    Molecular dialogue between arbuscular mycorrhizal fungi and the nonhost plant Arabidopsis thaliana switches from initial detection to antagonism

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    Approximately 29% of all vascular plant species are unable to establish an arbuscular mycorrhizal (AM) symbiosis. Despite this, AM fungi (Rhizophagus spp.) are enriched in the root microbiome of the nonhost Arabidopsis thaliana, and Arabidopsis roots become colonized when AM networks nurtured by host plants are available. Here, we investigated the nonhost–AM fungus interaction by analyzing transcriptional changes in Rhizophagus, Arabidopsis and the host plant Medicago truncatula while growing in the same mycorrhizal network. In early interaction stages, Rhizophagus activated the Arabidopsis strigolactone biosynthesis genes CCD7 and CCD8, suggesting that detection of AM fungi is not completely impaired. However, in colonized Arabidopsis roots, fungal nutrient transporter genes GintPT, GintAMT2, GintMST2 and GintMST4, essential for AM symbiosis, were not activated. RNA-seq transcriptome analysis pointed to activation of costly defenses in colonized Arabidopsis roots. Moreover, Rhizophagus colonization caused a 50% reduction in shoot biomass, but also led to enhanced systemic immunity against Botrytis cinerea. This suggests that early signaling between AM fungi and Arabidopsis is not completely impaired and that incompatibility appears at later interaction stages. Moreover, Rhizophagus-mediated defenses coincide with reduced Arabidopsis growth, but also with systemic disease resistance, highlighting the multifunctional role of AM fungi in host and nonhost interactions.This work was supported by the grant Marie Skłodowska-Curie Individual Fellowship ‘AraMyco’ H2020-MSCA-IF-2014 (to IF), grant no. 823.02.019 of the Netherlands Organization of Scientific Research (NWO), VIDI grant no. 11281 of the Dutch Technology Foundation STW (to SCMVW), and ERC Advanced Investigator grant no. 269072 of the European Research Council (to CMJP).Peer Reviewe

    Chemical Signals in Plant Resistance: Salicylic Acid

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    Salicylic Acid in Plant Disease Resistance

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    Salicylic Acid Biosynthesis and Metabolism

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    Salicylic acid (SA) has been shown to regulate various aspects of growth and development; it also serves as a critical signal for activating disease resistance in Arabidopsis thaliana and other plant species. This review surveys the mechanisms involved in the biosynthesis and metabolism of this critical plant hormone. While a complete biosynthetic route has yet to be established, stressed Arabidopsis appear to synthesize SA primarily via an isochorismate-utilizing pathway in the chloroplast. A distinct pathway utilizing phenylalanine as the substrate also may contribute to SA accumulation, although to a much lesser extent. Once synthesized, free SA levels can be regulated by a variety of chemical modifications. Many of these modifications inactivate SA; however, some confer novel properties that may aid in long distance SA transport or the activation of stress responses complementary to those induced by free SA. In addition, a number of factors that directly or indirectly regulate the expression of SA biosynthetic genes or that influence the rate of SA catabolism have been identified. An integrated model, encompassing current knowledge of SA metabolism in Arabidopsis, as well as the influence other plant hormones exert on SA metabolism, is presented
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