63,442 research outputs found

    Solutions of Conformal Turbulence on a Half Plane

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    Exact solutions of conformal turbulence restricted on a upper half plane are obtained. We show that the inertial range of homogeneous and isotropic turbulence with constant enstrophy flux develops in a distant region from the boundary. Thus in the presence of an anisotropic boundary, these exact solutions of turbulence generalize Kolmogorov's solution consistently and differ from the Polyakov's bulk case which requires a fine tunning of coefficients. The simplest solution in our case is given by the minimal model of p=2,q=33p=2, q=33 and moreover we find a fixed point of solutions when p,qp,q become large.Comment: 10pages, KHTP-93-07, SNUCTP-93-3

    Ubiquitin C-terminal hydrolase37 regulates Tcf7 DNA binding for the activation of Wnt signalling

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    The Tcf/Lef family of transcription factors mediates the Wnt/��-catenin pathway that is involved in a wide range of biological processes, including vertebrate embryogenesis and diverse pathogenesis. Post-translational modifications, including phosphorylation, sumoylation and acetylation, are known to be important for the regulation of Tcf/Lef proteins. However, the importance of ubiquitination and ubiquitin-mediated regulatory mechanisms for Tcf/Lef activity are still unclear. Here, we newly show that ubiquitin C-terminal hydrolase 37 (Uch37), a deubiquitinase, interacts with Tcf7 (formerly named Tcf1) to activate Wnt signalling. Biochemical analyses demonstrated that deubiquitinating activity of Uch37 is not involved in Tcf7 protein stability but is required for the association of Tcf7 to target gene promoter in both Xenopus embryo and human liver cancer cells. In vivo analyses further revealed that Uch37 functions as a positive regulator of the Wnt/��-catenin pathway downstream of ��-catenin stabilization that is required for the expression of ventrolateral mesoderm genes during Xenopus gastrulation. Our study provides a new mechanism for chromatin occupancy of Tcf7 and uncovers the physiological significance of Uch37 during early vertebrate development by regulating the Wnt/��-catenin pathway. ? 2017 The Author(s).113Ysciescopu

    Relevance of inter-composite fermion interaction to the edge Tomonaga-Luttinger liquid

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    It is shown that Wen's effective theory correctly describes the Tomonaga-Luttinger liquid at the edge of a system of non-interacting composite fermions. However, the weak residual interaction between composite fermions appears to be a relevant perturbation. The filling factor dependence of the Tomonaga-Luttinger parameter is estimated for interacting composite fermions in a microscopic approach and satisfactory agreement with experiment is achieved. It is suggested that the electron field operator may not have a simple representation in the effective one dimensional theory.Comment: 5 pages; accepted in Phys. Rev. Let

    SPEAR Far Ultraviolet Spectral Images of the Cygnus Loop

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    We present far-ultraviolet (FUV) spectral images, measured at C IV 1550, He II 1640, Si IV+O IV] 1400, and O III] 1664, of the entire Cygnus Loop, observed with the Spectroscopy of Plasma Evolution from Astrophysical Radiation (SPEAR) instrument, also known as FIMS. The spatial distribution of FUV emission generally corresponds with a limb-brightened shell, and is similar to optical, radio and X-ray images. The features found in the present work include a ``carrot'', diffuse interior, and breakout features, which have not been seen in previous FUV studies. Shock velocities of 140-160 km/s is found from a line ratio of O IV] to O III], which is insensitive not only to resonance scattering but also to elemental abundance. The estimated velocity indicates that the fast shocks are widespread across the remnant. By comparing various line ratios with steady-state shock models, it is also shown that the resonance scattering is widespread.Comment: 13 pages, 3 figures, 1 table, accepted for publication in ApJ

    A key to room-temperature ferromagnetism in Fe-doped ZnO: Cu

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    Successful synthesis of room-temperature ferromagnetic semiconductors, Zn1x_{1-x}Fex_{x}O, is reported. The essential ingredient in achieving room-temperature ferromagnetism in bulk Zn1x_{1-x}Fex_{x}O was found to be additional Cu doping. A transition temperature as high as 550 K was obtained in Zn0.94_{0.94}Fe0.05_{0.05}Cu0.01_{0.01}O; the saturation magnetization at room temperature reached a value of 0.75μB0.75 \mu_{\rm B} per Fe. Large magnetoresistance was also observed below 100100 K.Comment: 11 pages, 4 figures; to appear in Appl. Phys. Let

    Tuning Fermi-surface properties through quantum confinement in metallic meta-lattices: New metals from old atoms

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    We describe a new class of nanoscale structured metals wherein the effects of quantum confinement are combined with dispersive metallic electronic states to induce modifications to the fundamental low-energy microscopic properties of a three-dimensional metal: the density of states, the distribution of Fermi velocities, and the collective electronic response.Comment: 4 pages, 5 figures, to appear in Phys. Rev. Let
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