523 research outputs found

    The geography of strain: organizational resilience as a function of intergroup relations

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    Organizational resilience is an organization’s ability to absorb strain and preserve or improve functioning, despite the presence of adversity. In existing scholarship there is the implicit assumption that organizations experience and respond holistically to acute forms of adversity. We challenge this assumption by theorizing about how adversity can create differential strain, affecting parts of an organization rather than the whole. We argue that relations among those parts fundamentally shape organizational resilience. We develop a theoretical model that maps how the differentiated emergence of strain in focal parts of an organization triggers the movements of adjoining parts to provide or withhold resources necessary for the focal parts to adapt effectively. Drawing on core principles of theories about intergroup relations, we theorize about three specific pathways—integration, disavowal, and reclamation—by which responses of adjoining parts to focal part strain shape organizational resilience. We further theorize about influences on whether and when adjoining parts are likely to select different pathways. The resulting theory reveals how the social processes among parts of organizations influence member responses to adversity and, ultimately, organizational resilience. We conclude by noting the implications for organizational resilience theory, research, and practice.Accepted manuscrip

    Sequence analysis of an Archaeal virus isolated from a hypersaline lake in Inner Mongolia, China

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    <p>Abstract</p> <p>Background</p> <p>We are profoundly ignorant about the diversity of viruses that infect the domain <it>Archaea</it>. Less than 100 have been identified and described and very few of these have had their genomic sequences determined. Here we report the genomic sequence of a previously undescribed archaeal virus.</p> <p>Results</p> <p>Haloarchaeal strains with 16S rRNA gene sequences 98% identical to <it>Halorubrum saccharovorum </it>were isolated from a hypersaline lake in Inner Mongolia. Two lytic viruses infecting these were isolated from the lake water. The BJ1 virus is described in this paper. It has an icosahedral head and tail morphology and most likely a linear double stranded DNA genome exhibiting terminal redundancy. Its genome sequence has 42,271 base pairs with a GC content of ~65 mol%. The genome of BJ1 is predicted to encode 70 ORFs, including one for a tRNA. Fifty of the seventy ORFs had no identity to data base entries; twenty showed sequence identity matches to archaeal viruses and to haloarchaea. ORFs possibly coding for an origin of replication complex, integrase, helicase and structural capsid proteins were identified. Evidence for viral integration was obtained.</p> <p>Conclusion</p> <p>The virus described here has a very low sequence identity to any previously described virus. Fifty of the seventy ORFs could not be annotated in any way based on amino acid identities with sequences already present in the databases. Determining functions for ORFs such as these is probably easier using a simple virus as a model system.</p

    Leser-Trélat syndrome in patients affected by six multiple metachronous primitive cancers

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    Leser-Trélat syndrome is characterized by the eruptive appearance of multiple seborrheic keratoses in association with underlying malignant disease. Usually, the sign of Leser-Trélat is associated with adenocarcinoma, most frequently of the colon, breast, or stomach, but also of the lung, kidney, liver, and pancreas. Herein, we present a case that we believe is the first report of the sign of Leser-Trélat in association with occult gastric adenocarcinoma and the anamnestic oncologic history of five other multiple primitive cancers. Epidermal growth factor receptor (EGFR) immunohistochemical expression analysis of multiple seborrheic keratoses revealed an intense membranous staining in the basal keratinocytes and in all the upper epidermal layers. Patients with the sign of Leser-Trélat should undergo a diagnostic screening programme for malignant disease along with patients with known Leser-Trélat syndrome who present with a recent acute and florid eruption of their seborrheic keratoses. We propose the importance of combining the molecular features of multiple seborrheic keratoses with EGFR immunohistochemistry analyses to determine the likelihood of Leser-Trélat syndrome and the consequent high risk of underlying multiple visceral malignancies

    An NLO QCD analysis of inclusive cross-section and jet-production data from the ZEUS experiment

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    The ZEUS inclusive differential cross-section data from HERA, for charged and neutral current processes taken with e+ and e- beams, together with differential cross-section data on inclusive jet production in e+ p scattering and dijet production in \gamma p scattering, have been used in a new NLO QCD analysis to extract the parton distribution functions of the proton. The input of jet data constrains the gluon and allows an accurate extraction of \alpha_s(M_Z) at NLO; \alpha_s(M_Z) = 0.1183 \pm 0.0028(exp.) \pm 0.0008(model) An additional uncertainty from the choice of scales is estimated as \pm 0.005. This is the first extraction of \alpha_s(M_Z) from HERA data alone.Comment: 37 pages, 14 figures, to be submitted to EPJC. PDFs available at http://durpdg.dur.ac.uk/hepdata in LHAPDFv

    Measurement of event shapes in deep inelastic scattering at HERA

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    Inclusive event-shape variables have been measured in the current region of the Breit frame for neutral current deep inelastic ep scattering using an integrated luminosity of 45.0 pb^-1 collected with the ZEUS detector at HERA. The variables studied included thrust, jet broadening and invariant jet mass. The kinematic range covered was 10 < Q^2 < 20,480 GeV^2 and 6.10^-4 < x < 0.6, where Q^2 is the virtuality of the exchanged boson and x is the Bjorken variable. The Q dependence of the shape variables has been used in conjunction with NLO perturbative calculations and the Dokshitzer-Webber non-perturbative corrections (`power corrections') to investigate the validity of this approach.Comment: 7+25 pages, 6 figure

    Inclusive jet cross sections and dijet correlations in D±D^{*\pm} photoproduction at HERA

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    Inclusive jet cross sections in photoproduction for events containing a DD^* meson have been measured with the ZEUS detector at HERA using an integrated luminosity of 78.6pb178.6 {\rm pb}^{-1}. The events were required to have a virtuality of the incoming photon, Q2Q^2, of less than 1 GeV2^2, and a photon-proton centre-of-mass energy in the range 130<Wγp<280GeV130<W_{\gamma p}<280 {\rm GeV}. The measurements are compared with next-to-leading-order (NLO) QCD calculations. Good agreement is found with the NLO calculations over most of the measured kinematic region. Requiring a second jet in the event allowed a more detailed comparison with QCD calculations. The measured dijet cross sections are also compared to Monte Carlo (MC) models which incorporate leading-order matrix elements followed by parton showers and hadronisation. The NLO QCD predictions are in general agreement with the data although differences have been isolated to regions where contributions from higher orders are expected to be significant. The MC models give a better description than the NLO predictions of the shape of the measured cross sections.Comment: 43 pages, 12 figures, charm jets ZEU

    Dissociation of virtual photons in events with a leading proton at HERA

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    The ZEUS detector has been used to study dissociation of virtual photons in events with a leading proton, gamma^* p -> X p, in e^+p collisions at HERA. The data cover photon virtualities in two ranges, 0.03<Q^2<0.60 GeV^2 and 2<Q^2<100 GeV^2, with M_X>1.5 GeV, where M_X is the mass of the hadronic final state, X. Events were required to have a leading proton, detected in the ZEUS leading proton spectrometer, carrying at least 90% of the incoming proton energy. The cross section is presented as a function of t, the squared four-momentum transfer at the proton vertex, Phi, the azimuthal angle between the positron scattering plane and the proton scattering plane, and Q^2. The data are presented in terms of the diffractive structure function, F_2^D(3). A next-to-leading-order QCD fit to the higher-Q^2 data set and to previously published diffractive charm production data is presented

    Measurement of inclusive D*+- and associated dijet cross sections in photoproduction at HERA

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    Inclusive photoproduction of D*+- mesons has been measured for photon-proton centre-of-mass energies in the range 130 < W < 280 GeV and a photon virtuality Q^2 < 1 GeV^2. The data sample used corresponds to an integrated luminosity of 37 pb^-1. Total and differential cross sections as functions of the D* transverse momentum and pseudorapidity are presented in restricted kinematical regions and the data are compared with next-to-leading order (NLO) perturbative QCD calculations using the "massive charm" and "massless charm" schemes. The measured cross sections are generally above the NLO calculations, in particular in the forward (proton) direction. The large data sample also allows the study of dijet production associated with charm. A significant resolved as well as a direct photon component contribute to the cross section. Leading order QCD Monte Carlo calculations indicate that the resolved contribution arises from a significant charm component in the photon. A massive charm NLO parton level calculation yields lower cross sections compared to the measured results in a kinematic region where the resolved photon contribution is significant.Comment: 32 pages including 6 figure

    Beauty photoproduction measured using decays into muons in dijet events in ep collisions at s\sqrt{s}=318 GeV

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    The photoproduction of beauty quarks in events with two jets and a muon has been measured with the ZEUS detector at HERA using an integrated luminosity of 110 pb1^{- 1}. The fraction of jets containing b quarks was extracted from the transverse momentum distribution of the muon relative to the closest jet. Differential cross sections for beauty production as a function of the transverse momentum and pseudorapidity of the muon, of the associated jet and of xγjetsx_{\gamma}^{jets}, the fraction of the photon's momentum participating in the hard process, are compared with MC models and QCD predictions made at next-to-leading order. The latter give a good description of the data.Comment: 32 pages, 6 tables, 7 figures Table 6 and Figure 7 revised September 200

    Search for lepton-flavor violation at HERA

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    A search for lepton-flavor-violating interactions epμXe p \to \mu X and epτXe p\to \tau X has been performed with the ZEUS detector using the entire HERA I data sample, corresponding to an integrated luminosity of 130 pb^{-1}. The data were taken at center-of-mass energies, s\sqrt{s}, of 300 and 318 GeV. No evidence of lepton-flavor violation was found, and constraints were derived on leptoquarks (LQs) that could mediate such interactions. For LQ masses below s\sqrt{s}, limits were set on λeq1βq\lambda_{eq_1} \sqrt{\beta_{\ell q}}, where λeq1\lambda_{eq_1} is the coupling of the LQ to an electron and a first-generation quark q1q_1, and βq\beta_{\ell q} is the branching ratio of the LQ to the final-state lepton \ell (μ\mu or τ\tau) and a quark qq. For LQ masses much larger than s\sqrt{s}, limits were set on the four-fermion interaction term λeqαλqβ/MLQ2\lambda_{e q_\alpha} \lambda_{\ell q_\beta} / M_{\mathrm{LQ}}^2 for LQs that couple to an electron and a quark qαq_\alpha and to a lepton \ell and a quark qβq_\beta, where α\alpha and β\beta are quark generation indices. Some of the limits are also applicable to lepton-flavor-violating processes mediated by squarks in RR-Parity-violating supersymmetric models. In some cases, especially when a higher-generation quark is involved and for the process epτXe p\to \tau X , the ZEUS limits are the most stringent to date.Comment: 37 pages, 10 figures, Accepted by EPJC. References and 1 figure (Fig. 6) adde
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