Flux Recovery from Primal Hybrid Finite Element Methods

A flux recovery technique is introduced and analyzed for the computed solution of the primal hybrid finite element method for second-order elliptic problems. The recovery is carried out over a single element at a time while ensuring the continuity of the flux across the interelement edges and the validity of the discrete conservation law at the element level. Our construction is general enough to cover all degreesof polynomialsand gridsof triangular or quadrilateral type. We illustrate the principle using the Raviart–Thomas spaces, but other well-known related function spaces such as the Brezzi–Douglas–Marini (BDM) or Brezzi–Douglas–Fortin–Marini (BDFM) space can be used as well. An extension of the technique to the nonlinear case is given. Numerical results are presented to confirm the theoretical results

A General Framework for Constructing and Analyzing Mixed Finite Volume Methods on Quadrilateral Grids: The Overlapping Covolume Case

We present a general framework for constructing and analyzing finite volume methods applied to the mixed formulation of second-order elliptic problems on quadrilateral grids. The control volumes, or covolumes, in the grids overlap. An overlapping finite volume method of this type was first introduced by Russell in [T. F. Russell, Tech. report 3, Reservoir Simulation Research Corp., Tulsa, OK, 1995] and was tested for a variety of problems on rectangular and quadrilateral grids in [Z. Cai et al., Comput Geosci., 1 (1997), pp. 289–315]. Later in [S. H. Chou and D. Y. Kwak, SIAM J. Numer. Anal., 37 (2000), pp. 758–771], Chou and Kwak reformulated it as their mixed covolume method and proved optimal order error estimates using the covolume methodology from [S. H. Chou, Math. Comp., 66 (1997), pp. 85–104] and [S. H. Chou and D. Y. Kwak, SIAM J. Numer. Anal., 35 (1998), pp. 494–507]. However, their treatment was restricted to the case of diagonal coefficient tensor and rectangular grids since a different approach was needed for the quadrilateral (distorted rectangular) case. In this paper we give a new framework, which can handle not only the rectangular anisotropic case but also the anisotropic and irregular grid cases in which the locally supported test functions are images of the natural unit coordinate vectors under the Piola transformation. Our theory sheds light on how to create new test functions using quadratures and now covers Russell’s quadrilateral case

Haemodynamic and Clinical Assessment of Lateral Marginal Vein Excision in Patients with a Predominantly Venous Malformation of the Lower Extremity

ObjectiveThe purpose of the present study was to determine the effects of the surgical excision of lateral marginal veins (LMVs) in patients with a venous malformation (VM) affecting the lower extremity.MethodsPreoperative and postoperative air plethysmography (APG), CEAP classification C scores, and venous clinical severity scores (VCSS) of the 25 VM patients who underwent LMV excision were compared.ResultsAfter LMV excision, venous haemodynamic parameters revealed significantly increased ejection fraction (EF, 33.2 S.D.18.5% vs. 39.7 S.D.21.2%, P=.020), and reduced venous volume (VV, 235.0 S.D.141.8ml vs. 198.0 S.D.114.1ml, P=.016) and residual venous fraction (RVF, 62.4 S.D. 26.6% vs. 56.9 S.D. 25.3%, P=.046). Clinical assessments of affected limbs revealed significantly improved mean CEAP C scores and VCSS (preoperative score, 4.4 S.D.1.7 vs. postoperative score 2.4 S.D.1.7, P=.026) after LMV excision versus preoperative data.ConclusionHaemodynamic and clinical improvements were observed in patients with lower extremity VM after LMV excision

Gauge coupling renormalization in orbifold field theories

We investigate the gauge coupling renormalization in orbifold field theories preserving 4-dimensional N=1 supersymmetry in the framework of 4-dimensional effective supergravity. As a concrete example, we consider the 5-dimensional Super-Yang-Mills theory on a slice of AdS_5. In our approach, one-loop gauge couplings can be determined by the loop-induced axion couplings and the tree level properties of 4-dimensional effective supergravity which are much easier to be computed.Comment: 18 pages, JHEP style; 1-loop corrections to gauge kinetic functions are fully computed, references are adde

Computed terahertz near-field mapping of molecular resonances of lactose stereo-isomer impurities with sub-attomole sensitivity

Terahertz near-field microscopy (THz-NFM) could locally probe low-energy molecular vibration dynamics below diffraction limits, showing promise to decipher intermolecular interactions of biomolecules and quantum matters with unique THz vibrational fingerprints. However, its realization has been impeded by low spatial and spectral resolutions and lack of theoretical models to quantitatively analyze near-field imaging. Here, we show that THz scattering-type scanning near-field optical microscopy (THz s-SNOM) with a theoretical model can quantitatively measure and image such low-energy molecular interactions, permitting computed spectroscopic near-field mapping of THz molecular resonance spectra. Using crystalline-lactose stereo-isomer (anomer) mixtures (i.e., alpha-lactose (>= 95%, w/w) and beta-lactose (<= 4%, w/w)), THz s-SNOM resolved local intermolecular vibrations of both anomers with enhanced spatial and spectral resolutions, yielding strong resonances to decipher conformational fingerprint of the trace beta-anomer impurity. Its estimated sensitivity was similar to 0.147 attomoles in similar to 8 x 10(-4) mu m(3) interaction volume. Our THz s-SNOM platform offers a new path for ultrasensitive molecular fingerprinting of complex mixtures of biomolecules or organic crystals with markedly enhanced spatio-spectral resolutions. This could open up significant possibilities of THz technology in many fields, including biology, chemistry and condensed matter physics as well as semiconductor industries where accurate quantitative mappings of trace isomer impurities are critical but still challenging.11Ysciescopu

High-precision THz Dielectric Spectroscopy of Tris-HCl Buffer

Tris-HCl buffer solution is extensively used in biochemistry and molecular biology to maintain a stablepH for biomolecules such as nucleic acids and proteins. Here we report on the high-precision THz dielectricspectroscopy of a 10 mM Tris-HCl buffer. Using a double Debye model, including conductivity of ionicspecies, we measured the complex dielectric functions of Tris-HCl buffer. The fast relaxation time of watermolecules in Tris-HCl buffer is ~20% longer than that in pure water while the slow relaxation time changeslittle. This means that the reorientation dynamics of Tris-HCl buffer with such a low Tris concentrationis quite different from that of pure water.1111Ysciescopuskc

Mixed Bino-Wino-Higgsino Dark Matter in Gauge Messenger Models

Almost degenerate bino and wino masses at the weak scale is one of unique features of gauge messenger models. The lightest neutralino is a mixture of bino, wino and higgsino and can produce the correct amount of the dark matter density if it is the lightest supersymmetric particle. Furthermore, as a result of squeezed spectrum of superpartners which is typical for gauge messenger models, various co-annihilation and resonance regions overlap and very often the correct amount of the neutralino relic density is generated as an interplay of several processes. This feature makes the explanation of the observed amount of the dark matter density much less sensitive to fundamental parameters. We calculate the neutralino relic density assuming thermal history and present both spin independent and spin dependent cross sections for the direct detection. We also discuss phenomenological constraints from b to s gamma and muon g-2 and compare results of gauge messenger models to well known results of the mSUGRA scenario.Comment: 27 pages, 9 figures, references added, version to appear at JCA

Arabidopsis ABCG14 is essential for the root-to-shoot translocation of cytokinin.

Cytokinins are phytohormones that induce cytokinesis and are essential for diverse developmental and physiological processes in plants. Cytokinins of the trans-zeatin type are mainly synthesized in root vasculature and transported to the shoot, where they regulate shoot growth. However, the mechanism of long-distance transport of cytokinin was hitherto unknown. Here, we report that the Arabidopsis ATP-binding cassette (ABC) transporter subfamily G14 (AtABCG14) is mainly expressed in roots and plays a major role in delivering cytokinins to the shoot. Loss of AtABCG14 expression resulted in severe shoot growth retardation, which was rescued by exogenous trans-zeatin application. Cytokinin content was decreased in the shoots of atabcg14 plants and increased in the roots, with consistent changes in the expression of cytokinin-responsive genes. Grafting of atabcg14 scions onto wild-type rootstocks restored shoot growth, whereas wild-type scions grafted onto atabcg14 rootstocks exhibited shoot growth retardation similar to that of atabcg14. Cytokinin concentrations in the xylem are reduced by similar to 90% in the atabcg14 mutant. These results indicate that AtABCG14 is crucial for the translocation of cytokinin to the shoot. Our results provide molecular evidence for the long-distance transport of cytokinin and show that this transport is necessary for normal shoot development.open118380Ysciescopu

Zinc oxide thin-film transistors fabricated at low temperature by chemical spray pyrolysis

We report the electrical behavior of undoped zinc oxide thin-film transistors (TFTs) fabricated by low-temperature chemical spray pyrolysis. An aerosol system utilizing aerodynamic focusing was used to deposit the ZnO. Polycrystalline films were subsequently formed by annealing at the relatively low temperature of 140°C. The saturation mobility of the TFTs was 2 cm2/Vs, which is the highest reported for undoped ZnO TFTs manufactured below 150°C. The devices also had an on/off ratio of 104 and a threshold voltage of −3.5 V. These values were found to depend reversibly on measurement conditions