155 research outputs found

    Magnetic Fields in the Milky Way

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    This chapter presents a review of observational studies to determine the magnetic field in the Milky Way, both in the disk and in the halo, focused on recent developments and on magnetic fields in the diffuse interstellar medium. I discuss some terminology which is confusingly or inconsistently used and try to summarize current status of our knowledge on magnetic field configurations and strengths in the Milky Way. Although many open questions still exist, more and more conclusions can be drawn on the large-scale and small-scale components of the Galactic magnetic field. The chapter is concluded with a brief outlook to observational projects in the near future.Comment: 22 pages, 5 figures, to appear in "Magnetic Fields in Diffuse Media", eds. E.M. de Gouveia Dal Pino and A. Lazaria

    Strong Decays of Strange Quarkonia

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    In this paper we evaluate strong decay amplitudes and partial widths of strange mesons (strangeonia and kaonia) in the 3P0 decay model. We give numerical results for all energetically allowed open-flavor two-body decay modes of all nsbar and ssbar strange mesons in the 1S, 2S, 3S, 1P, 2P, 1D and 1F multiplets, comprising strong decays of a total of 43 resonances into 525 two-body modes, with 891 numerically evaluated amplitudes. This set of resonances includes all strange qqbar states with allowed strong decays expected in the quark model up to ca. 2.2 GeV. We use standard nonrelativistic quark model SHO wavefunctions to evaluate these amplitudes, and quote numerical results for all amplitudes present in each decay mode. We also discuss the status of the associated experimental candidates, and note which states and decay modes would be especially interesting for future experimental study at hadronic, e+e- and photoproduction facilities. These results should also be useful in distinguishing conventional quark model mesons from exotica such as glueballs and hybrids through their strong decays.Comment: 69 pages, 5 figures, 39 table

    Managing to lead in private enterprise in China: Work values, demography and the development of trust

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    Previous work on trust has focused on employee trust in management. However, issues of how leaders develop trust in their followers in leader-member exchange (LMX) are under-explored. Based on theories of leader-member exchange, attribution and industrial convergence, this study investigates how the work values of leaders influence the development of their trust in followers and how this is moderated by demographic factors. A survey of 219 leaders was conducted in privately owned enterprises in China. The findings suggest that the work value of centralization is negatively related to leader trust in follower predictability. Group orientation and formalization are positively related to the development of trust in follower good faith. Moreover, age and level of formal education are found to moderate significantly the relationships between leader work values and development of their trust in followers within the context of China. Copyright © 2007 SAGE Publications

    Appraising empirical applications of Structuration Theory in management and organization studies

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    There is an increasing interest in the application of Structuration Theory in the fields of management and organization studies. Based upon a thorough literature review, we have come up with a data-set to assess how Structuration Theory has been used in empirical research. We use three key concepts of this theory (duality of structure, knowledgeability, and time-space) as sensitizing concepts for our analysis. We conclude that the greatest potential of Structuration Theory for management and organization studies is to view it as a process theory that offers a distinct building block for explaining intra and interorganizational change, as exemplified through concepts such as routine, script, genre, practice, and discourse

    Exotic ρ±ρ0\rho^\pm\rho^0 state photoproduction

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    It is shown that the list of unusual mesons planned for a careful study in photoproduction can be extended by the exotic states X±(1600)X^\pm(1600) with IG(JPC)=2+(2++)I^G(J ^{PC})=2^+(2^{++}) which should be looked for in the ρ±ρ0\rho^\pm\rho^0 decay channels in the reactions γNρ±ρ0N\gamma N\to\rho^\pm\rho^0N and γNρ±ρ0Δ\gamma N\to\rho^\pm \rho^0\Delta. The full classification of the ρ±ρ0\rho^\pm\rho^0 states by their quantum numbers is presented. A simple model for the spin structure of the γpf2(1270)p \gamma p\to f_2(1270)p, γpa20(1320)p\gamma p\to a^0_2(1320)p, and γNX±(N,Δ)\gamma N\to X^\pm (N, \Delta) reaction amplitudes is formulated and the tentative estimates of the corresponding cross sections at the incident photon energy Eγ6E_\gamma\approx 6 GeV are obtained: σ(γpf2(1270)p)0.12\sigma(\gamma p\to f_2(1270)p)\approx0.12 μ\mub, σ(γpa20(1320)p)0.25 \sigma(\gamma p\to a^0_2(1320)p)\approx0.25 μ\mub, σ(γNX±Nρ±ρ0N)0.018\sigma(\gamma N\to X^\pm N\to\rho^\pm\rho^0N)\approx0.018 μ\mub, and σ(γpXΔ++ρρ0Δ++)0.031\sigma(\gamma p\to X^-\Delta^{++ }\to\rho^-\rho^0\Delta^{++})\approx0.031 μ\mub. The problem of the X±X^\pm signal extraction from the natural background due to the other π±π0π+π\pi^\pm\pi^0 \pi^+\pi^- production channels is discussed. In particular the estimates are presented for the γph1(1170)π+n\gamma p\to h_1(1170)\pi^+n, γpρ+nπ+π0π+πn\gamma p\to\rho'^{+}n\to \pi^+\pi^0\pi^+\pi^-n, and γpωρ0p\gamma p\to\omega\rho^0p reaction cross sections. Our main conclusion is that the search for the exotic X±(2+(2++))X^\pm(2^+(2^{++})) states is quite feasible at JEFLAB facility. The expected yield of the γNX±Nρ±ρ0N\gamma N\to X^\pm N\to\rho^\pm\rho^0N events in a 30-day run at the 100% detection efficiency approximates 2.8×1062.8\times10^6 events.Comment: 19 pages, revtex, 1 figure in postscipt, some comments and references added, a few minor typos corrected, to be published in Phys. Rev.

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
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