3,831 research outputs found

    The Chinese classroom paradox: A cross-cultural comparison of teacher controlling behaviors

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    Depth enhancement of optical scanning holography with a spiral phase plate

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    Poster Session (DW2A): no. DW2A.3A spiral phase plate is applied to the optical scanning holography system to improve the depth resolution of the reconstruction, the simulation results show that the depth interval can be resolved at a 0.4 mm with only a single hologram. © 2015 OSApostprin

    A new fuzzy classifier with triangular membership functions

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    Fuzzy logic is widely applied in control and modeling for its robustness, simplicity and clarity. It is also applied in classifier design with rules directly generated from numerical data. Some available rule generation methods, however, are either too complicated to implement or impractical for high dimensions. In this paper, we propose a new fuzzy classifier architecture. At the very beginning the training data is clustered at the input space. Fuzzy sets are then defined based on these clusters with triangular membership function. The outputs in the rule conclusion are initially determined by the “normalized vote” in the corresponding cluster. Fuzzy sets and conclusions can be adjusted through training. The proposed fuzzy system is simple in structure, and can be fast trained and easily implemented. Its classification performance is generally better than artificial neural network.published_or_final_versio

    D-amino acids govern stationary phase cell wall remodeling in bacteria

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    4 pages, 4 figures.-- PMID: 19762646 [PubMed].-- Supporting information available at: http://www.sciencemag.org/cgi/content/full/sci;325/5947/1552/DC1In all known organisms, amino acids are predominantly thought to be synthesized and used as their L-enantiomers. Here, we found that bacteria produce diverse D-amino acids as well, which accumulate at millimolar concentrations in supernatants of stationary phase cultures. In Vibrio cholerae, a dedicated racemase produced D-Met and D-Leu, whereas Bacillus subtilis generated D-Tyr and D-Phe. These unusual D-amino acids appear to modulate synthesis of peptidoglycan, a strong and elastic polymer that serves as the stress-bearing component of the bacterial cell wall. D-Amino acids influenced peptidoglycan composition, amount, and strength, both by means of their incorporation into the polymer and by regulating enzymes that synthesize and modify it. Thus, synthesis of D-amino acids may be a common strategy for bacteria to adapt to changing environmental conditions.This work was supported by Howard Hughes Medical Institute (HHMI); NIH AI-R37-42347 (M.K.W.) and CA24487 and GM086258 (J.C.); Ministry of Education and Science, Spain (MEC) BFU2006-04574 and Fundación Ramón Areces (M.A.P.); Jane Coffin Childs Fellowship (H.L.); MEC Fellowship (F.C.); and HHMI Exceptional Research Opportunities (EXROP) (C.N.T.).Peer reviewe

    How ready is China for a China-style world order? China's state media discourse under construction

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    What exactly is the China-style world order that Chinese officials and intellectual elites have recently been talking about, and how ready is China for it? An examination and analysis of discourses on ‘Africa Live’ on CCTV Africa, the first overseas news center of China Central Television (CCTV), yields some highly noticeable features and significant themes, confirming that although China has shifted from a low-profile approach to a more assertive one, in an attempt to change the global order, its verbal challenge and sometimes harsh criticism of the American-led international system is accompanied by an obvious absence of a clear vision of what the new world order should be like. This lack of a clear vision may be due to the fact that the Chinese discourse on world order is still a work in progress, constrained by internal practices, and Africa is its testing ground for the construction of a discourse that China envisages as an alternative

    Observation of a New Charmed Strange Meson

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    Using the CLEO-II detector, we have obtained evidence for a new meson decaying to D0K+D^0 K^+. Its mass is 2573.21.6+1.7±0.8±0.52573.2^{+1.7}_{-1.6}\pm 0.8\pm 0.5 {}~MeV/c2c^2 and its width is 164+5±316^{+5}_{-4}\pm 3~MeV/c2c^2. Although we do not establish its spin and parity, the new meson is consistent with predictions for an L=1L=1, S=1S=1, JP=2+J_P=2^+ charmed strange state.Comment: 9 pages uuencoded compressed postscript (process with uudecode then gunzip). hardcopies with figures can be obtained by sending mail to: [email protected]

    Measurement of the branching fraction for Υ(1S)τ+τ\Upsilon (1S) \to \tau^+ \tau^-

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    We have studied the leptonic decay of the Υ(1S)\Upsilon (1S) resonance into tau pairs using the CLEO II detector. A clean sample of tau pair events is identified via events containing two charged particles where exactly one of the particles is an identified electron. We find B(Υ(1S)τ+τ)=(2.61 ± 0.12 +0.090.13)B(\Upsilon(1S) \to \tau^+ \tau^-) = (2.61~\pm~0.12~{+0.09\atop{-0.13}})%. The result is consistent with expectations from lepton universality.Comment: 9 pages, RevTeX, two Postscript figures available upon request, CLNS 94/1297, CLEO 94-20 (submitted to Physics Letters B

    Precision Measurement of the Ds+Ds+D_s^{*+}- D_s^+ Mass Difference

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    We have measured the vector-pseudoscalar mass splitting M(Ds+)M(Ds+)=144.22±0.47±0.37MeVM(D_s^{*+})-M(D_s^+) = 144.22\pm 0.47\pm 0.37 MeV, significantly more precise than the previous world average. We minimize the systematic errors by also measuring the vector-pseudoscalar mass difference M(D0)M(D0)M(D^{*0})-M(D^0) using the radiative decay D0D0γD^{*0}\rightarrow D^0\gamma, obtaining [M(Ds+)M(Ds+)][M(D0)M(D0)]=2.09±0.47±0.37MeV[M(D_s^{*+})-M(D_s^+)]-[M(D^{*0})-M(D^0)] = 2.09\pm 0.47\pm 0.37 MeV. This is then combined with our previous high-precision measurement of M(D0)M(D0)M(D^{*0})-M(D^0), which used the decay D0D0π0D^{*0}\rightarrow D^0\pi^0. We also measure the mass difference M(Ds+)M(D+)=99.5±0.6±0.3M(D_s^+)-M(D^+)=99.5\pm 0.6\pm 0.3 MeV, using the ϕπ+\phi\pi^+ decay modes of the Ds+D_s^+ and D+D^+ mesons.Comment: 18 pages uuencoded compressed postscript (process with uudecode then gunzip). hardcopies with figures can be obtained by sending mail to: [email protected]
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