6,046 research outputs found

    Endophytic Fungi of Bitter Melon \u3ci\u3e(Momordica Charantia)\u3c/i\u3e in Guangdong Province, China

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    Endophytic fungi can mutualistically interact with their host plants by deterring herbivores. Overall 1172 endophytic fungal isolates were recovered from roots, stems, leaves, flowers and fruits of bitter melon, Momordica charantia, at five sites in Guangdong Province. These isolates were identified to 25 genera using morphological and molecular characteristics. The endophyte communities at the five sites were similar. Alternaria alternata, Aspergillus spp., Cladosporium spp., Colletotrichum spp., Nigrospora spp., Penicillium spp., Arthrinium spp., Chaetimium spp., Curvularia spp., Fusarium spp., Phoma spp., and Phomopsis spp. were isolated from at least three of the five sites. The coefficient of similarity for endophytes ranged from 60.6% to 83.3% between any two sites. There were significant differences in the species composition of endophytes recovered from different tissues of bitter melon. Fusarium spp. was the most frequent in root and stem samples, Colletotrichum spp. in leaf samples, A. alternata in flower samples, and Cladosporium spp. in fruit samples. The coefficients of similarity for endophytes were between 42.9% and 80.0% from any two tissues. We found that the composition of endophytes of bitter melon was relatively stable across sites, but differed greatly among tissues. We also found that there were fewer insects such as aphids (Homoptera: Aphididae), leafminers (Lepidoptera, Gracillariidae), and cotton leafworms Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) collected from the leaves of bitter melon at the Huadu site compared to those collected at the Yunfu site. Whether this is related to the endophyte communities isolated from different sites requires further research

    Progress of Enantioselective Nitrile Biotransformations in Organic Synthesis

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    Recent progress of enantioselective biotransformations of nitriles including various functionalized nitriles, ?-hydroxy and ?-amino nitriles, oxirane- and aziridine-containing carbonitriles is summarized in this short review article

    Stabilization of positive switched systems with time-varying delays under asynchronous switching

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    This paper investigates the state feedback stabilization problem for a class of positive switched systems with time-varying delays under asynchronous switching in the frameworks of continuous-time and discrete-time dynamics. The so-called asynchronous switching means that the switches between the candidate controllers and system modes are asynchronous. By constructing an appropriate co-positive type Lyapunov-Krasovskii functional and further allowing the functional to increase during the running time of active subsystems, sufficient conditions are provided to guarantee the exponential stability of the resulting closed-loop systems, and the corresponding controller gain matrices and admissible switching signals are presented. Finally, two illustrative examples are given to show the effectiveness of the proposed methods

    Hybrid mesons from anisotropic lattice QCD with the clover and improved gauge actions

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    We study hybrid mesons from the clover and improved gauge actions at β=2.6\beta=2.6 on the anisotropic 123×3612^3\times36 lattice using our PC cluster. We estimate the mass of 1−+1^{-+} light quark hybrid as well as the mass of the charmonium hybrid. The improvement of both quark and gluonic actions, first applied to the hybrid mesons, is shown to be more efficient in reducing the lattice spacing and finite volume errors.Comment: Lattice2002 (spectrum

    Capturing The Digital Dollar: How Religious Nonprofits Are Adopting Social Media for Adoption, Engagement, and Community

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    The objective of this thesis was to quantify the impact of religious, media-related nonprofit adoption rate, online presence, and online giving technology. Specifically, this thesis focuses on the nonprofits’ adoption, use, and interactivity on Facebook, Instagram, Twitter, and YouTube. This thesis study was rooted in Rogers’ Diffusion of Innovations Theory, and its constructs were used to best understand the adoption and impact of use within the religious nonprofit sector (Rogers, 2003). First, the researcher defined and evaluated the nonprofit’s active online presence, sophistication of technology integration, and impact of these findings. Second, the researcher quantitatively examined audience interactivity. Targeting a niche nonprofit group that has an understanding of online presence and content creation (religious, media-related nonprofits) significantly revealed that the extent of digital innovation and social media used was not dependent on the amount of revenue. This study provides the level of adoption of social media and online donation tools and audience interactivity that can assist nonprofits to efficiently invest their resources for a better return on investment on a digital, online scale

    Exotic mesons from quantum chromodynamics with improved gluon and quark actions on the anisotropic lattice

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    Hybrid (exotic) mesons, which are important predictions of quantum chromodynamics (QCD), are states of quarks and anti-quarks bound by excited gluons. First principle lattice study of such states would help us understand the role of ``dynamical'' color in low energy QCD and provide valuable information for experimental search for these new particles. In this paper, we apply both improved gluon and quark actions to the hybrid mesons, which might be much more efficient than the previous works in reducing lattice spacing error and finite volume effect. Quenched simulations were done at β=2.6\beta=2.6 and on a ξ=3\xi=3 anisotropic 123×3612^3\times36 lattice using our PC cluster. We obtain 2013±26±712013 \pm 26 \pm 71 MeV for the mass of the 1−+1^{-+} hybrid meson qˉqg{\bar q}qg in the light quark sector, and 4369±37±994369 \pm 37 \pm 99Mev in the charm quark sector; the mass splitting between the 1−+1^{-+} hybrid meson cˉcg{\bar c}c g in the charm quark sector and the spin averaged S-wave charmonium mass is estimated to be 1302±37±991302 \pm 37 \pm 99 MeV. As a byproduct, we obtain 1438±32±571438 \pm 32 \pm 57 MeV for the mass of a P-wave 1++1^{++} uˉu{\bar u}u or dˉd{\bar d}d meson and 1499±28±651499 \pm 28 \pm 65 MeV for the mass of a P-wave 1++1^{++} sˉs{\bar s}s meson, which are comparable to their experimental value 1426 MeV for the f1(1420)f_1(1420) meson. The first error is statistical, and the second one is systematical. The mixing of the hybrid meson with a four quark state is also discussed.Comment: 12 pages, 3 figures. Published versio
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