1,450 research outputs found

    Pole analysis on the hadron spectroscopy of ΛbJ/ΨpK\Lambda_b\to J/\Psi p K^-

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    In this paper we study the J/ΨpJ/\Psi p spectroscopy in the process of ΛbJ/ΨpK\Lambda_b\to J/\Psi p K^-. The final state interactions of coupled channel J/ΨpJ/\Psi p ~-~ DˉΣc\bar{D} \Sigma_c~-~DˉΣc\bar{D}^{*} \Sigma_c are constructed based on K-matrix with the Chew-Mandelstam function. We build the ΛbJ/ΨpK\Lambda_b\to J/\Psi p K^- amplitude according to the Au-Morgan-Pennington method. The event shape is fitted and the decay width of ΛbJ/ΨpK\Lambda_b\to J/\Psi p K^- is used to constrain the parameters, too. With the amplitudes we extract out the poles and their residues. Our amplitude and pole analysis suggest that the Pc(4312)P_c(4312) should be DˉΣc\bar{D}\Sigma_c molecule, the Pc(4440)P_c(4440) could be an S-wave compact pentaquark state, and the structure around Pc(4457)P_c(4457) is caused by the cusp effect. The future experimental measurement of the decays of ΛbDˉΣcK\Lambda_b\to \bar{D}\Sigma_c K^- and ΛbDˉΣcK\Lambda_b\to \bar{D}^*\Sigma_c K^- would further help to study the nature of these resonances.Comment: updated to the published versio

    Triaqua-1κO,2κ2 O-bis­(2,2′-bipyridine)-1κ2 N,N′;2κ2 N,N′-chlorido-1κCl-μ-terephthalato-1:2κ2 O 1:O 4-dicopper(II) nitrate monohydrate

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    In the binuclear title compound, [Cu2(C8H4O4)Cl(C10H8N2)2(H2O)3]NO3·H2O, the two crystallographically independent CuII ions have similar coordination environments. One of the CuII ions has a square-pyramidal arrangement, which is defined by a water mol­ecule occupying the apical position, with the equatorial ligators consisting of two N atoms from a 2,2′-bipyridine mol­ecule, one carboxyl­ate O atom from a terephthalate ligand and one O atom from a water mol­ecule. The other CuII ion has a similar coordination environment, except that the apical position is occupied by a chloride ligand instead of a water mol­ecule. An O—H⋯O and O—H⋯Cl hydrogen-bonded three-dimensional network is formed between the components

    Dichlorido(4′-ferrocenyl-2,2′:6′,2′′-terpyridine-κ3 N,N′,N′′)zinc acetonitrile monosolvate

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    The title complex, [FeZn(C5H5)Cl2(C20H14N3)]·CH3CN, is composed of one ZnII atom, one 4′-ferrocenyl-2,2′:6′,2′′-terpyridine (fctpy) ligand, two Cl atoms and one acetonitrile solvent mol­ecule. The ZnII atom is five-coordinated in a trigonal–bipyramidal geometry by the tridentate chelating fctpy ligand and two Cl atoms

    Heme oxygenase-1 plays a pro-life role in experimental brain stem death via nitric oxide synthase I/protein kinase G signaling at rostral ventrolateral medulla

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    <p>Abstract</p> <p>Background</p> <p>Despite its clinical importance, a dearth of information exists on the cellular and molecular mechanisms that underpin brain stem death. A suitable neural substrate for mechanistic delineation on brain stem death resides in the rostral ventrolateral medulla (RVLM) because it is the origin of a life-and-death signal that sequentially increases (pro-life) and decreases (pro-death) to reflect the advancing central cardiovascular regulatory dysfunction during the progression towards brain stem death in critically ill patients. The present study evaluated the hypothesis that heme oxygnase-1 (HO-1) may play a pro-life role as an interposing signal between hypoxia-inducible factor-1 (HIF-1) and nitric oxide synthase I (NOS I)/protein kinase G (PKG) cascade in RVLM, which sustains central cardiovascular regulatory functions during brain stem death.</p> <p>Methods</p> <p>We performed cardiovascular, pharmacological, biochemical and confocal microscopy experiments in conjunction with an experimental model of brain stem death that employed microinjection of the organophosphate insecticide mevinphos (Mev; 10 nmol) bilaterally into RVLM of adult male Sprague-Dawley rats.</p> <p>Results</p> <p>Western blot analysis coupled with laser scanning confocal microscopy revealed that augmented HO-1 expression that was confined to the cytoplasm of RVLM neurons occurred preferentially during the pro-life phase of experimental brain stem death and was antagonized by immunoneutralization of HIF-1α or HIF-1β in RVLM. On the other hand, the cytoplasmic presence of HO-2 in RVLM neurons manifested insignificant changes during both phases. Furthermore, immunoneutralization of HO-1 or knockdown of <it>ho-1 </it>gene in RVLM blunted the augmented life-and-death signals exhibited during the pro-life phase. Those pretreatments also blocked the upregulated pro-life NOS I/PKG signaling without affecting the pro-death NOS II/peroxynitrite cascade in RVLM.</p> <p>Conclusions</p> <p>We conclude that transcriptional upregulation of HO-1 on activation by HIF-1 in RVLM plays a preferential pro-life role by sustaining central cardiovascular regulatory functions during brain stem death via upregulation of NOS I/PKG signaling pathway. Our results further showed that the pro-dead NOS II/peroxynitrite cascade in RVLM is not included in this repertoire of cellular events.</p

    Poly[[[bis­(acetato-κO)copper(II)]-μ-1,4-diimidazol-1-ylbenzene-κ2 N 3:N 3′] dihydrate]

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    In the title linear coordination polymer, {[Cu(C2H3O2)2(C12H10N4)]·2H2O}n, the CuII atom is coordinated by two N atoms from two different symmetry-related 1,4-diimidazol-1-ylbenzene (dib) ligands and two carboxyl­ate O atoms from two acetate ligands in a square-planar geometry. The Cu atoms are linked by the dib ligands, forming an extended chain. These chains are linked by O—H⋯O hydrogen bonds into a three-dimensional supra­molecular network. The CuII atom lies on a center of inversion

    Constructing a precipitable water vapor map from regional GNSS network observations without collocated meteorological data for weather forecasting

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    Surface pressure (Ps) and weighted mean temperature (Tm) are two necessary variables for the accurate retrieval of precipitable water vapor (PWV) from Global Navigation Satellite System (GNSS) zenith total delay (ZTD) estimates. The lack of Ps or Tm information is a concern for those GNSS sites that are not collocated with meteorological sensors. This paper investigates an alternative method of inferring accurate Ps and Tm at the GNSS station using nearby synoptic observations. Ps and Tm obtained at the nearby synoptic sites are interpolated onto the location of the GNSS station by performing both vertical and horizontal adjustments, in which the parameters involved in Ps and Tm calculation are estimated from ERA-Interim reanalysis profiles. In addition, we present a method of constructing high-quality PWV maps through vertical reduction and horizontal interpolation of the retrieved GNSS PWVs. To evaluate the performances of the Ps and Tm retrieval, and the PWV map construction, GNSS data collected from 58 stations of the Hunan GNSS network and synoptic observations from 20 nearby sites in 2015 were processed to extract the PWV so as to subsequently generate the PWV maps. The retrieved Ps and Tm and constructed PWV maps were assessed by the results derived from radiosonde and the ERA-Interim reanalysis. The results show that (1) accuracies of Ps and Tm derived by synoptic interpolation are within the range of 1.7–3.0&thinsp;hPa and 2.5–3.0&thinsp;K, respectively, which are much better than the GPT2w model; (2) the constructed PWV maps have good agreements with radiosonde and ERA-Interim reanalysis data with the overall accuracy being better than 3&thinsp;mm; and (3) PWV maps can well reveal the moisture advection, transportation and convergence during heavy rainfall.</p

    Nature of the X(6900)X(6900) in partial wave decomposition of J/ψJ/ψJ/\psi J/\psi scattering

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    In this letter, we perform partial wave decomposition on coupled channel scattering amplitudes, J/ψJ/ψJ/\psi J/\psi-J/ψψ(2S)J/\psi \psi(2S)-J/ψψ(3770)J/\psi \psi(3770), to study the resonance appears in these processes. Effective Lagrangians are used to describe the interactions of four charmed vector mesons, and the scattering amplitudes are calculated up to the next-to-leading order. Partial wave projections are performed, and unitarization is implemented by Pad\'e approximation. Then we fit the amplitudes to the J/ψJ/ψJ/\psi J/\psi invariant mass spectra measured by LHCb and determine the unknown couplings. The pole parameters of the X(6900)X(6900) are extracted as M=6861.08.8+6.3M=6861.0^{+6.3}_{-8.8}~MeV and Γ=129.03.4+5.6\Gamma=129.0^{+5.6}_{-3.4}~MeV. Our analysis implies that its quantum number prefers to be 0++0^{++}. The pole counting rule and phase shifts show that it is a normal Breit-Wigner resonance and hence should be a compact tetraquark.Comment: 6 pages, 4 figure

    Transactive Memory System, Job Competence and Individual Performance

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    The purpose of this paper is to understand important variables that impact individual performance within a team. This will enhance knowledge management within a team context and facilitate competence development of individuals. This research proposes and examines a multi-level model which elaborates how transactive memory system and job competence (i.e., technology competence and teamwork competence) affect individual performance. An empirical study was conducted with 19 teams of television news reporters, with 211 valid survey responses. Hierarchical linear modeling was applied to analyze the data. The result indicated that transactive memory system and technology competence helped to improve a reporter’s job performance. Furthermore, the relationships were fully mediated by teamwork competence. Our findings thus suggest teamwork competence is the core. Neither technology competence nor transactive memory system will necessarily translate directly into enhanced individual performance. Therefore, for organizational investment on transactive memory system and digital technologies to take effect, management should help develop the employee’s teamwork competence

    DAMA/NaI results

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    The DAMA/NaI set-up of the DAMA experiment has been operative during seven annual cycles and has investigated several rare processes. In particular, it has been realised in order to investigate the model independent annual modulation signature for Dark Matter particles in the galactic halo. With the total exposure collected in the seven annual cycles (107731 kg day) a model independent evidence for the presence of a Dark Matter particle component in the galactic halo has been pointed out at 6.3 sigma C.L.. Some of the many possible corollary model dependent quests for the candidate particle have been presented as well.Comment: Contributed paper to the Rencontres de Moriond "Electroweak Interactions and Unified Theories", La Thuile, Aosta Valley, Italy, March 200
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