458 research outputs found

    The relationship between leadership behaviors and subordinates' job stress in Taiwan

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    The purpose of this study was to investigate the relationship between leadership styles and subordinates' job stress in Taiwan. It was predicted that less supportive, less approachable, less communicative, more controlling leaders who use less delegation will have subordinates reporting more job stress; and that the "control" factor will be the strongest predictor of subordinates' job stress. Furthermore, it was hypothesized that overall leaders will tend to underestimate their subordinates' job stress, but that leaders who are trusted, approachable, and more communicative, will be more accurate in their perceptions of subordinates' job stress. A questionnaire was designed that included demographic items and measures of leadership style and job stress. Leadership style was measured using the Leadership Orientations scale (Bolman & Deal, 1997), and three factors extracted from the Leader Behavior Description Questionnaire (Initiation, Consideration, and Tolerance of Freedom (Delegation)) (Stogdill, 1963; Stogdill, Goode & Day, 1962). The scale measuring job stress was the Perceived Job Stress Scale (modified from the Perceived Stress Scale, Cohen, Kamarck & Mermelstein, 1983). Data was collected from 174 complete work groups (e.g., 1 leader plus 4 subordinates) from Taiwanese companies. Results indicated that leader support, approachability, and communication are important predictors of subordinates' stress. A significant difference was found between leaders' rating of subordinate stress and the subordinates' ratings. Implications of the findings are discussed and future research directions are suggested

    The modified method of reanalysis wind data in estuarine areas

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    High-quality wind field data are key to improving the accuracy of storm surge simulations in coastal and estuarine water. These data are also of great significance in studying the dynamic processes in coastal areas and safeguarding human engineering structures. A directional correction method for ECMWF reanalysis wind data was proposed in this paper based on the correlation with the measured wind speed and direction. The results show that the accuracies of wind speed and direction were improved after being modified by the correction method proposed in this paper. The modified wind data were applied to drive the storm surge model of the Yangtze Estuary for typhoon events, which resulted in a significant improvement to the accuracy of hindcasted water levels. The error of the hindcasted highest water levels was reduced by 16–19 cm

    Atomistic nucleation sites of Pt nanoparticles on N-doped carbon nanotubes

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    [[abstract]]The atomistic nucleation sites of Pt nanoparticles (Pt NPs) on N-doped carbon nanotubes (N-CNTs) were investigated using C and N K-edge and Pt L3-edge X-ray absorption near-edge structure (XANES)/extended X-ray absorption fine structure (EXAFS) spectroscopy. Transmission electron microscopy and XANES/EXAFS results revealed that the self-organized Pt NPs on N-CNTs are uniformly distributed because of the relatively high binding energies of the adsorbed Pt atoms at the imperfect sites. During the atomistic nucleation process of Pt NPs on N-CNTs, stable Pt–C and Pt–N bonds are presumably formed, and charge transfer occurs at the surface/interface of the N-CNTs. The findings in this study were consistent with density functional theory calculations performed using cluster models for the undoped, substitutional-N-doped and pyridine-like-N-doped CNTs.[[journaltype]]國外[[incitationindex]]SCI[[booktype]]紙本[[countrycodes]]GB

    Identification of dendritic cell precursor from the CD11c+ cells expressing high levels of MHC class II molecules in the culture of bone marrow with FLT3 ligand

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    Dendritic cells (DCs) are readily generated from the culture of mouse bone marrow (BM) treated with either granulocyte macrophage-colony stimulating factor (GM-CSF) or FMS-like tyrosine kinase 3 ligand (FLT3L). CD11c+MHCII+ or CD11c+MHCIIhi cells are routinely isolated from those BM cultures and generally used as in vitro-generated DCs for a variety of experiments and therapies. Here, we examined CD11c+ cells in the BM culture with GM-CSF or FLT3L by staining with a monoclonal antibody 2A1 that is known to recognize mature or activated DCs. Most of the cells within the CD11c+MHCIIhi DC gate were 2A1+ in the BM culture with GM-CSF (GM-BM culture). In the BM culture with FLT3L (FL-BM culture), almost of all the CD11c+MHCIIhi cells were within the classical DC2 (cDC2) gate. The analysis of FL-BM culture revealed that a majority of cDC2-gated CD11c+MHCIIhi cells exhibited a 2A1-CD83-CD115+CX3CR1+ phenotype, and the others consisted of 2A1+CD83+CD115-CX3CR1- and 2A1-CD83-CD115-CX3CR1- cells. According to the antigen uptake and presentation, morphologies, and gene expression profiles, 2A1-CD83-CD115-CX3CR1- cells were immature cDC2s and 2A1+CD83+CD115-CX3CR1- cells were mature cDC2s. Unexpectedly, however, 2A1-CD83-CD115+CX3CR1+ cells, the most abundant cDC2-gated MHCIIhi cell subset in FL-BM culture, were non-DCs. Adoptive cell transfer experiments in the FL-BM culture confirmed that the cDC2-gated MHCIIhi non-DCs were precursors to cDC2s, i.e., MHCIIhi pre-cDC2s. MHCIIhi pre-cDC2s also expressed the higher level of DC-specific transcription factor Zbtb46 as similarly as immature cDC2s. Besides, MHCIIhi pre-cDC2s were generated only from pre-cDCs and common DC progenitor (CDP) cells but not from monocytes and common monocyte progenitor (cMoP) cells, verifying that MHCIIhi pre-cDC2s are close lineage to cDCs. All in all, our study identified and characterized a new cDC precursor, exhibiting a CD11c+MHCIIhiCD115+CX3CR1+ phenotype, in FL-BM culture

    Global, regional, and national burden of hepatitis B, 1990-2019: a systematic analysis for the Global Burden of Disease Study 2019

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    Search for hidden-charm tetraquark with strangeness in e+eK+DsD0+c.c.e^{+}e^{-}\rightarrow K^+ D_{s}^{*-} D^{*0}+c.c.

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    We report a search for a heavier partner of the recently observed Zcs(3985)Z_{cs}(3985)^{-} state, denoted as ZcsZ_{cs}^{\prime -}, in the process e+eK+DsD0+c.c.e^{+} e^{-}\rightarrow K^{+}D_{s}^{*-}D^{* 0}+c.c., based on e+ee^+e^- collision data collected at the center-of-mass energies of s=4.661\sqrt{s}=4.661, 4.682 and 4.699 GeV with the BESIII detector. The ZcsZ_{cs}^{\prime -} is of interest as it is expected to be a candidate for a hidden-charm and open-strange tetraquark. A partial-reconstruction technique is used to isolate K+K^+ recoil-mass spectra, which are probed for a potential contribution from ZcsDsD0Z_{cs}^{\prime -}\to D_{s}^{*-}D^{* 0} (c.c.c.c.). We find an excess of ZcsDsD0Z_{cs}^{\prime -}\rightarrow D_{s}^{*-}D^{*0} (c.c.c.c.) candidates with a significance of 2.9σ2.9\sigma, after considering systematic uncertainties, at a mass of (4123.5±0.7stat.±1.1syst.)MeV/c2(4123.5 \pm 0.7_{\mathrm{stat.}} \pm 1.1_{\mathrm{syst.}}) \mathrm{MeV}/c^{2}. As the data set is limited in size, the upper limits are evaluated at the 90% confidence level on the product of the Born cross section and the branching fraction of ZcsDsD0Z_{cs}^{\prime-}\rightarrow D_{s}^{*-}D^{* 0}, σBornB\sigma^{\rm Born}\cdot\mathcal{B} at the three energy points, under different assumptions of the ZcsZ_{cs}^{\prime -} mass from 4.120 to 4.140 MeV and of the width from 10 to 50 MeV. Under various mass and width assumptions, the upper limits of σBornB\sigma^{\rm Born}\cdot\mathcal{B} are found to lie in the range of 262\sim6, 373\sim7 and 363\sim6 pb at s=4.661\sqrt{s}=4.661, 4.682 and 4.699 GeV, respectively. The larger data samples that will be collected in the coming years will allow a clearer picture to emerge concerning the existence and nature of the ZcsZ_{cs}^{\prime -} state.Comment: 17 pages, 7 figure

    Production of doubly-charged Δ\Delta baryon in e+ee^{+}e^{-} annihilation at energies from 2.3094 to 2.6464 GeV

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    The processes e+eΔ++Δˉe^{+}e^{-} \to \Delta^{++}\bar{\Delta}^{--} and e+eΔ++pˉπ+c.c.e^{+}e^{-}\to \Delta^{++} \bar{p} \pi^{-} + c.c. are studied for the first time with 179 pb1179~{\rm pb}^{-1} of e+ee^{+}e^{-} annihilation data collected with the BESIII detector at center-of-mass energies from 2.30942.3094 GeV to 2.64642.6464 GeV. No significant signal for the e+eΔ++Δˉe^{+}e^{-}\to \Delta^{++}\bar{\Delta}^{--} process is observed and the upper limit of the Born cross section is estimated at each energy point. For the process e+eΔ++pˉπ+c.c.e^{+}e^{-} \to \Delta^{++} \bar{p} \pi^{-} + c.c., a significant signal is observed at center-of-mass energies near 2.6454 GeV and the corresponding Born cross section is reported.Comment: 10 pages, 4 figure

    Search for an axion-like particle in J/ψJ/\psi radiative decays

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    We search for an axion-like particle (ALP) aa through the process ψ(3686)π+πJ/ψ\psi(3686)\rightarrow\pi^+\pi^-J/\psi, J/ψγaJ/\psi\rightarrow\gamma a, aγγa\rightarrow\gamma\gamma in a data sample with (2708.1±14.5)×106(2708.1\pm14.5)\times10^6 ψ(3686)\psi(3686) events collected by the BESIII detector. No significant ALP signal is observed over the expected background, and the upper limits on the branching fraction of the decay J/ψγaJ/\psi\rightarrow\gamma a and the ALP-photon coupling constant gaγγg_{a\gamma\gamma} are set at the 95\% confidence level in the mass range of 0.165\leq m_a\leq2.84\,\mbox{GeV}/c^2. The limits on B(J/ψγa)\mathcal{B}(J/\psi\rightarrow\gamma a) range from 8.3×1088.3\times10^{-8} to 1.8×1061.8\times10^{-6} over the search region, and the constraints on the ALP-photon coupling are the most stringent to date for 0.165\leq m_a\leq1.468\,\mbox{GeV}/c^2.Comment: 10 pages, 5 figure

    Observation of D+KS0a0(980)+D^{+}\to K_{S}^{0}a_{0}(980)^{+} in the amplitude analysis of D+KS0π+ηD^{+} \to K_{S}^{0}\pi^+\eta

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    We perform for the first time an amplitude analysis of the decay D+KS0π+ηD^{+}\to K_{S}^{0}\pi^+\eta and report the observation of the decay D+KS0a0(980)+D^{+}\to K_{S}^{0}a_{0}(980)^{+} using 2.93 fb1^{-1} of e+ee^+e^- collision data taken at a center-of-mass energy of 3.773 GeV with the BESIII detector. As the only W-annihilation free decay among DD to a0(980)a_{0}(980)-pseudoscalar, D+KS0a0(980)+D^{+}\to K_{S}^{0}a_{0}(980)^{+} is the ideal decay to extract the contributions of the external and internal WW-emission amplitudes involving a0(980)a_{0}(980) and study the final-state interactions. The absolute branching fraction of D+KS0π+ηD^{+}\to K_{S}^{0}\pi^+\eta is measured to be (1.27±0.04stat.±0.03syst.)%(1.27\pm0.04_{\rm stat.}\pm0.03_{\rm syst.})\%. The product branching fractions of D+KS0a0(980)+D^{+}\to K_{S}^{0}a_{0}(980)^{+} with a0(980)+π+ηa_{0}(980)^{+}\to \pi^+\eta and D+π+K0(1430)0D^{+}\to \pi^+ K_0^*(1430)^0 with K0(1430)0KS0ηK_0^*(1430)^0\to K_{S}^{0}\eta are measured to be (1.33±0.05stat.±0.04syst.)%(1.33\pm0.05_{\rm stat.}\pm0.04_{\rm syst.})\% and (0.14±0.03stat.±0.01syst.)%(0.14\pm0.03_{\rm stat.}\pm0.01_{\rm syst.})\%, respectively

    Observation of the semileptonic decays D0KS0ππ0e+νeD^0\rightarrow K_S^0\pi^-\pi^0 e^+ \nu_e and D+KS0π+πe+νeD^+\rightarrow K_S^0\pi^+\pi^- e^+ \nu_e

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    By analyzing e+ee^+e^- annihilation data corresponding to an integrated luminosity of 2.93 fb1\rm fb^{-1} collected at a center-of-mass energy of 3.773 GeV with the \text{BESIII} detector, the first observation of the semileptonic decays D0KS0ππ0e+νeD^0\rightarrow K_S^0\pi^-\pi^0 e^+ \nu_e and D+KS0π+πe+νeD^+\rightarrow K_S^0\pi^+\pi^- e^+ \nu_e is reported. With a dominant hadronic contribution from K1(1270)K_1(1270), the branching fractions are measured to be B(D0K1(1270)(KS0ππ0)e+νe)=(1.690.46+0.53±0.15)×104\mathcal{B}(D^0\rightarrow {K}_1(1270)^-(\to K^0_S\pi^-\pi^0)e^+\nu_e)=(1.69^{+0.53}_{-0.46}\pm0.15)\times10^{-4} and B(D+Kˉ1(1270)0(KS0π+π)e+νe)=(1.470.40+0.45±0.20)×104\mathcal{B}(D^+\to \bar{K}_1(1270)^0(\to K^0_S\pi^+\pi^-)e^+\nu_e)=(1.47^{+0.45}_{-0.40}\pm0.20)\times10^{-4} with statistical significance of 5.4σ\sigma and 5.6σ\sigma, respectively. When combined with measurements of the K1(1270)K+ππK_1(1270)\to K^+\pi^-\pi decays, the absolute branching fractions are determined to be B(D0K1(1270)e+νe)=(1.050.28+0.33±0.12±0.12)×103\mathcal{B}(D^0\to K_1(1270)^-e^+\nu_e)=(1.05^{+0.33}_{-0.28}\pm0.12\pm0.12)\times10^{-3} and B(D+Kˉ1(1270)0e+νe)=(1.290.35+0.40±0.18±0.15)×103\mathcal{B}(D^+\to \bar{K}_1(1270)^0e^+\nu_e)=(1.29^{+0.40}_{-0.35}\pm0.18\pm0.15)\times10^{-3}. The first and second uncertainties are statistical and systematic, respectively, and the third uncertainties originate from the assumed branching fractions of the K1(1270)KππK_1(1270)\to K\pi\pi decays.Comment: 19page
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