3,769 research outputs found

    Nuclear geometry effect and transport coefficient in semi-inclusive lepton-production of hadrons off nuclei

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    Hadron production in semi-inclusive deep-inelastic scattering of leptons from nuclei is an ideal tool to determine and constrain the transport coefficient in cold nuclear matter. The leading-order computations for hadron multiplicity ratios are performed by means of the SW quenching weights and the analytic parameterizations of quenching weights based on BDMPS formalism. The theoretical results are compared to the HERMES positively charged pions production data with the quarks hadronization occurring outside the nucleus. With considering the nuclear geometry effect on hadron production, our predictions are in good agreement with the experimental measurements. The extracted transport parameter from the global fit is shown to be q^=0.74±0.03GeV2/fm\hat{q} = 0.74\pm0.03 GeV^2/fm for the SW quenching weight without the finite energy corrections. As for the analytic parameterization of BDMPS quenching weight without the quark energy E dependence, the computed transport coefficient is q^=0.20±0.02GeV2/fm\hat{q} = 0.20\pm0.02 GeV^2/fm. It is found that the nuclear geometry effect has a significant impact on the transport coefficient in cold nuclear matter. It is necessary to consider the detailed nuclear geometry in studying the semi-inclusive hadron production in deep inelastic scattering on nuclear targets.Comment: 14 pages, 3 figures. arXiv admin note: text overlap with arXiv:1310.569

    F-wave heavy-light meson spectroscopy in QCD sum rules and heavy quark effective theory

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    We study the F-wave c_bar s heavy meson doublets (2+,3+) and (3+,4+). They have large orbital excitations L=3, and may be good challenges (tests) for theoretical studies. To study them we use the method of QCD sum rule in the framework of heavy quark effective theory. Their masses are predicted to be m_{(2+,3+)} = (3.45 \pm 0.25, 3.50 \pm 0.26) GeV and m_{(3+,4+)} = (3.20 \pm 0.22, 3.26 \pm 0.23) GeV, with mass splittings Delta m_{(2+,3+)} = m_{3+} - m_{2+} = 0.046 \pm 0.030 GeV and Delta m_{(3+,4+)} = 0.053 \pm 0.044 GeV, respectively. We note that this is a pioneering work and these results are provisional.Comment: 10 pages, 8 figures, 3 tables, accepted by PR

    A role of corazonin receptor in larval-pupal transition and pupariation in the oriental fruit fly Bactrocera dorsalis (Hendel) (Diptera: Tephritidae)

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    Corazonin (Crz) is a neuropeptide hormone, but also a neuropeptide modulator that is internally released within the CNS, and it has a widespread distribution in insects with diverse physiological functions. Here, we identified and cloned the cDNAs of Bactrocera dorsalis that encode Crz and its receptor CrzR. Mature BdCrz has 11 residues with a unique Ser11 substitution (instead of the typical Asn) and a His in the evolutionary variable position 7. The BdCrzR cDNA encodes a putative protein of 608 amino acids with 7 putative transmembrane domains, typical for the structure of G-protein-coupled receptors. When expressed in Chinese hamster ovary (CHO) cells, the BdCrzR exhibited a high sensitivity and selectivity for Crz (EC50 approximate to 52.5 nM). With qPCR, the developmental stage and tissue-specific expression profiles in B. dorsalis demonstrated that both BdCrz and BdCrzR were highly expressed in the larval stage, and BdCrzR peaked in 2-day-old 3rd-instar larvae, suggesting that the BdCrzR may play an important role in the larval-pupal transition behavior. Immunochemical localization confirmed the production of Crz in the central nervous system (CNS), specifically by a group of three neurons in the dorso-lateral protocerebrum and eight pairs of lateral neurons in the ventral nerve cord. qPCR analysis located the BdCrzR in both the CNS and epitracheal gland, containing the Inka cells. Importantly, dsRNA-BdCrzR-mediated gene-silencing caused a delay in larval-pupal transition and pupariation, and this phenomenon agreed with a delayed expression of tyrosine hydroxylase and dopa-decarboxylase genes. We speculate that CrzR-silencing blocked dopamine synthesis, resulting in the inhibition of pupariation and cuticular melanization. Finally, injection of Crz in head-ligated larvae could rescue the effects. These findings provide a new insight into the roles of Crz signaling pathway components in B. dorsalis and support an important role of CrzR in larval-pupal transition and pupariation behavior

    浅谈护士长非权力影响力与护理人员工作投入水平的关系

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    Objective: To explore the effects of the headnurses’ non-power influenceon the nurses’ work engagement. Methods: To conduct a questionnaire survey on 450 nurses of the clinical nursing units of The Peoples' Hospital of Jilin Province.Results: The non-power  influence of the headnurseshave a director indirect positive influence on thenurses’ work engagement. Conclusion: The  hospitals and nursing managers should take effective measures to promote the non-power influence, then to promote the level of nursing staffs’ work engagement, to organize and promote the nursing work of the hospital. 目的  探讨护士长非权力影响力对护士工作投入的影响。方法  对吉林省人民医院临床护理单元450名护士进行护士长非权力影响力量表和护理人员工作投入量表的问卷调查。 结果  护士长非权力影响力对护理人员工作投入具有直接和间接的正性影响。结论  医院和护理管理者应采取有效的措施提升非权力影响力,进而提升护理人员的工作投入水平,组织和推动医院护理工作

    VPA: an R tool for analyzing sequencing variants with user-specified frequency pattern

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    <p>Abstract</p> <p>Background</p> <p>The massive amounts of genetic variant generated by the next generation sequencing systems demand the development of effective computational tools for variant prioritization.</p> <p>Findings</p> <p>VPA (Variant Pattern Analyzer) is an R tool for prioritizing variants with specified frequency pattern from multiple study subjects in next-generation sequencing study. The tool starts from individual files of variant and sequence calls and extract variants with user-specified frequency pattern across the study subjects of interest. Several position level quality criteria can be incorporated into the variant extraction. It can be used in studies with matched pair design as well as studies with multiple groups of subjects.</p> <p>Conclusions</p> <p>VPA can be used as an automatic pipeline to prioritize variants for further functional exploration and hypothesis generation. The package is implemented in the R language and is freely available from <url>http://vpa.r-forge.r-project.org</url>.</p

    Explaining the cosmic ray spectrum feature of Auger beyond the ankle with dip model plus the galactic propagation effect

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    The Auger Collaboration has recently published the energy spectrum of cosmic rays above 1 EeV, which exhibits interesting features. These spectrum features provide an opportunity to investigate the propagation of ultra-high-energy cosmic rays (UHECRs). In this study, we have developed a model that incorporates the dip model for UHECRs in the extragalactic propagation, while accounting for the suppression due to diffusion and interactions within the galaxy. Our model demonstrates excellent agreement with the energy spectrum measured by Auger and supports a spectral index of 2 for the diffusion coefficient in the galaxy starting from 5×10185\times10^{18}eV.Comment: 5 pages, 2 figure

    Effects of losses in the hybrid atom-light interferometer

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    Enhanced Raman scattering can be obtained by injecting a seeded light field which is correlated with the initially prepared collective atomic excitation. This Raman amplification process can be used to realize atom-light hybrid interferometer. We numerically calculate the phase sensitivities and the signal-to-noise ratios of this interferometer with the method of homodyne detection and intensity detection, and give their differences between this two methods. In the presence of loss of light field and atomic decoherence the measure precision will be reduced which can be explained by the break of the intermode decorrelation conditions of output modesComment: 9 pages, 7 figure
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