2,281 research outputs found

    The existence and stability of nonlinear wave equations

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    Second order nonlinear wave equation solution on Hilbert space with stability and uniquenes

    Smoothened adopts multiple active and inactive conformations capable of trafficking to the primary cilium.

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    Activation of Hedgehog (Hh) signaling requires the transmembrane protein Smoothened (Smo), a member of the G-protein coupled receptor superfamily. In mammals, Smo translocates to the primary cilium upon binding of Hh ligands to their receptor, Patched (Ptch1), but it is unclear if ciliary trafficking of Smo is sufficient for pathway activation. Here, we demonstrate that cyclopamine and jervine, two structurally related inhibitors of Smo, force ciliary translocation of Smo. Treatment with SANT-1, an unrelated Smo antagonist, abrogates cyclopamine- and jervine-mediated Smo translocation. Further, activation of protein kinase A, either directly or through activation of Galphas, causes Smo to translocate to a proximal region of the primary cilium. We propose that Smo adopts multiple inactive and active conformations, which influence its localization and trafficking on the primary cilium

    Photoconduction and the electronic structure of silica nanowires embedded with gold nanoparticles

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    [[abstract]]Silica nanowires (SiOx-NWs) embedded with Au peapods have been studied by energy-filtered scanning transmission electron microscopy (EFTEM), O K- and Au L3-edge x-ray absorption near-edge structure (XANES), and extended x-ray absorption fine structure (EXAFS), x-ray emission spectroscopy (XES) and scanning photoelectron microscopy. XANES and XES data show that band gaps of Au-peapod-embedded and pure SiOx-NWs were 6.8 eV. In additional, XANES and EXAFS results indicate illumination-induced electron transfer from Au peapod to SiOx-NWs and does not show any feature attributable to the formation of Au-Si bonding in the Au peapod embedded in SiOx-NWs with or without illumination. Photoresponse and EFTEM measurements show that green light has more significant enhancement of photoconductivity than red and blue light due to surface plasmon resonance and suggest that transport of electrons across SiOx-NWs is via Mott-variable-range hopping mechanism through localized or defect states.[[incitationindex]]SCI[[booktype]]紙

    Numerical analyses for improved terminal velocity of deep water torpedo anchor

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    Purpose: This research aims to investigate the effects of manipulation of a torpedo’s geometries to attain higher terminal velocity. The parameters of interest include geometric changes of the original design, as well as sea water properties that reflect water depth in South China Sea. Design/methodology/approach: The research make use of computational fluid dynamics (CFD) software, FLUENT, to solve viscous incompressible Navier–Stokes equations with two equations k-epsilon turbulent model. The calculated drag coefficient is subsequently used to calculate the maximum attainable terminal velocity of the torpedo. Findings: It was found that the terminal velocity can be improved by sharper tip angle, greater aspect ratio, greater diameter ratio and optimum rear angle at 30°. Sensitivity of drag coefficient toward each of the parameters is established in this paper. Originality/value: The paper, in addition to verifying the importance of aspect ratio, has also established the tip angle, diameter ratio and rear angle of the torpedo as important geometric aspects that could be tuned to improve its terminal velocity

    Electeonic structures of group-III-nitride nanorods studied by x-ray absorption, x-ray emission, and Raman spectroscopy

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    [[abstract]]Nitrogen N and metal Al, Ga, and In K-edge x-ray absorption near-edge structure XANES , x-ray emission spectroscopy XES , and Raman scattering measurements were performed to elucidate the electronic structures of group-III–nitride nanorods and thin films of AlN, GaN, and InN. XANES spectra show slight increase of the numbers of unoccupied N p states in GaN and AlN nanorods, which may be attributed to a slight increase of the degree of localization of conduction band states. The band gaps of AlN, GaN, and InN nanorods are determined by an overlay of XES and XANES spectra to be 6.2, 3.5, and 1.9 eV, respectively, which are close to those of AlN and GaN bulk/films and InN polycrystals.[[notice]]補正完畢[[journaltype]]國外[[incitationindex]]SCI[[booktype]]紙本[[booktype]]電子版[[countrycodes]]US

    Hole Pockets in the Doped 2D Hubbard Model

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    The electronic momentum distribution n(k){\rm n({\bf k})} of the two dimensional Hubbard model is studied for different values of the coupling U/t{\rm U/t}, electronic density n{\rm \langle n \rangle}, and temperature, using quantum Monte Carlo techniques. A detailed analysis of the data on 8×88\times 8 clusters shows that features consistent with hole pockets at momenta k=(±π2,±π2){\rm {\bf k}=(\pm {\pi\over{2}},\pm {\pi\over{2}})} appear as the system is doped away from half-filling. Our results are consistent with recent experimental data for the cuprates discussed by Aebi et al. (Phys. Rev. Lett. {\bf 72}, 2757 (1994)). In the range of couplings studied, the depth of the pockets is maximum at n0.9{\rm \langle n \rangle \approx 0.9}, and it increases with decreasing temperature. The apparent absence of hole pockets in previous numerical studies of this model is explained.Comment: 11 pages, 4 postscript figures appended, RevTeX (version 3.0

    Mechanism of glycan receptor recognition and specificity switch for avian, swine, and human adapted influenza virus hemagglutinins: a molecular dynamics perspective.

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    Hemagglutinins (HA's) from duck, swine, and human influenza viruses have previously been shown to prefer avian and human glycan receptor analogues with distinct topological profiles, pentasaccharides LSTa (alpha-2,3 linkage) and LSTc (alpha-2,6 linkage), in comparative molecular dynamics studies. On the basis of detailed analyses of the dynamic motions of the receptor binding domains (RBDs) and interaction energy profiles with individual glycan residues, we have identified approximately 30 residue positions in the RBD that present distinct profiles with the receptor analogues. Glycan binding constrained the conformational space sampling by the HA. Electrostatic steering appeared to play a key role in glycan binding specificity. The complex dynamic behaviors of the major SSE and trimeric interfaces with or without bound glycans suggested that networks of interactions might account for species specificity in these low affinity and high avidity (multivalent) interactions between different HA and glycans. Contact frequency, energetic decomposition, and H-bond analyses revealed species-specific differences in HA-glycan interaction profiles, not readily discernible from crystal structures alone. Interaction energy profiles indicated that mutation events at the set of residues such as 145, 156, 158, and 222 would favor human or avian receptor analogues, often through interactions with distal asialo-residues. These results correlate well with existing experimental evidence, and suggest new opportunities for simulation-based vaccine and drug development

    t(5;6)(q33-34;q23) CEP85L/PDGFRB

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    Review on t(5;6)(q33-34;q23) CEP85L/PDGFRB, with data on clinics, and the genes involved

    Surface Wave Modes on Spherical Cavities Excited by Incident Ultrasound

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    It has been shown both experimentally and theoretically1 that ultrasonic waves propagate circumferentially around the surface of cavities in an elastic medium, besides being reflected from its “flash points”. Surface wave returns were seen to decisively influence the time structure of the echo return from incident ultrasonic pulses. Nagase2 has solved a characteristic equation applicable to the spherical cavity problem, from which it could be shown3 that the surface of a spherical cavity supports a Rayleigh-type and two (P and S) Franz-type surface waves, of known speeds and dispersions. On the other hand, the complex eigenfrequencies of cavities were recently obtained numerically4. We have used these numerical results in order to satisfy Nagase’s solutions, presented in the form of propagation constants of the surface waves as series of fractional powers of the frequency, and have obtained in this way a mode number assignment for all the complex eigenfrequencies. Using this, we calculate dispersion curves for the Rayleigh, P and S- type surface wave phase velocities; their knowledge will permit an accurate interpretation of ultrasonic scattering experiments1, which previously could be analyzed in a qualitative way only

    Drawing from Grotowski and Beyond: Kuo Pao Kun’s Discourse on Audiences in Singapore in the 1980s

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    Much has been researched on Kuo Pao Kun’s multilingualism and multiculturalism. However, as one of one of the most important Asian dramatists, the analysis of Kuo’s discourse on audiences remains largely unexplored. There is a pressing need to understand the ways which theatre practitioners imagine audiences as it points to issues of subjectivity, audience participation and social engagement, especially in a neoliberal society like Singapore where people are often positioned as docile economic subjects. Among the many Asian and Western dramatists Kuo drew inspiration from, Jerzy Grotowski was pivotal. This essay seeks to address this gap by examining how the latter’s ideas was crucial to understanding how Kuo envisioned theatre and audiences alongside his artistic practice
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