Pomerons and BCFW recursion relations for strings on D-branes

We derive pomeron vertex operators for bosonic strings and superstrings in the presence of D-branes. We demonstrate how they can be used in order to compute the Regge behavior of string amplitudes on D-branes and the amplitude of ultrarelativistic D-brane scattering. After a lightning review of the BCFW method, we proceed in a classification of the various BCFW shifts possible in a field/string theory in the presence of defects/D-branes. The BCFW shifts present several novel features, such as the possibility of performing single particle momentum shifts, due to the breaking of momentum conservation in the directions normal to the defect. Using the pomeron vertices we show that superstring amplitudes on the disc involving both open and closed strings should obey BCFW recursion relations. As a particular example, we analyze explicitly the case of 1→1$1\to 1$ scattering of level one closed string states off a D-brane. Finally, we investigate whether the eikonal Regge regime conjecture holds in the presence of D-branes.     

Geometry + Simulation Modules: Implementing Isogeometric Analysis

Isogeometric analysis (IGA) is a recently developed simulation method that allows integration of finite element analysis (FEA) with conventional computer-aided design (CAD) software [1,3]. This goal requires new software design strategies, in order to enable the use of CAD data in the analysis pipeline. To this end, we have initiated G + SMO (Geometry+Simulation Modules), an open-source, C++ library for IGA. G + SMO is an object-oriented, template library, that implements a generic concept for IGA, based on abstract classes for discretization basis, geometry map, assembler, solver and so on. It makes use of object polymorphism and inheritance techniques to provide a common framework for IGA, for a variety of different basis-types which are available. A highlight of our design is the dimension independent code, realized by means of template meta-programming. Some of the features already available include computing with B-spline, Bernstein, NURBS bases, as well as hierarchical and truncated hierarchical bases of arbitrary polynomial order. These basis functions are used in continuous and discontinuous Galerkin approximation of PDEs over (non-)conforming multi-patch computational (physical) domains. (© 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Circulating Ligands of the Receptor for Advanced Glycation End Products and the Soluble Form of the Receptor Modulate Cardiovascular Cell Apoptosis in Diabetes

We determined whether plasma concentrations of the receptor for advanced glycation end products (RAGE) and the soluble (s) form of RAGE (sRAGE) in healthy individuals and patients with type 2 diabetes (T2D) modulate vascular remodeling. Healthy individuals and patients with T2D were divided into two age groups: young = <35 years old or middle-aged (36–64 years old) and stratified based on normal glucose tolerance (NGT), impaired (IGT), and T2D. Plasma titers of sRAGE, the RAGE ligands, AGEs, S100B, S100A1, S100A6, and the apoptotic marker Fas ligand Fas(L) were measured by enzyme-linked immunosorbent assay (ELISA). The apoptotic potential of the above RAGE ligands and sRAGE were assessed in cultured adult rat aortic smooth muscle cells (ASMC). In NGT individuals, aging increased the circulating levels of AGEs and S100B and decreased sRAGE, S100A1 and S100A6. Middle-aged patients with T2D presented higher levels of circulating S100B, AGEs and FasL, but lower levels of sRAGE, S100A1 and S100A6 than individuals with NGT or IGT. Treatment of ASMC with either AGEs or S100B at concentrations detected in T2D patients increased markers of inflammation and apoptosis. Responses attenuated by concomitant administration of sRAGE. In middle-aged patients with T2D, lower circulating plasma levels of sRAGE may limit decoy and exogenous trapping of deleterious pro-apoptotic/pro-inflammatory RAGE ligands AGEs and S100B, increasing the risk for diabetic complications.     

Aggregational behavior in water,of some polyamphiphiles derived from reactive polymers

Selected polyamphiphiles were prepared by the method of reactive polymers, i.e., interaction of polymaleic anhydride and polyacryloyl chloride with certain long chain alcohols. The aggregational behavior of these polyamphiphiles in water was studied by video-enhanced differential interference contrast microscopy, as well as by absorption and fluorescence spectroscopy. The formation of large aggregates was observed by video technique, while inter- and intramolecular micelles were detected by spectroscopic © 1993 John Wiley & Sons, Inc.     

On the population dynamics induced by an attosecond train interacting coherently with an atomic system within the electric dipole approximation

The population dynamics induced in an atomic system by XUV-attosecond radiation have been investigated within the electric dipole approximation. The main characteristics of the dynamics are explained in simple terms, extending our previous work on coherent laser-atom interactions in the XUV spectral region. Attosecond beating appearing in a second-order autocorrelation of a coherent superposition of high order harmonics, is investigated from the perspective of a superposition of Rabi oscillations, as well as of coherent population return (CPR). The work reveals the strength of attosecond radiation as a tool for time domain studies of coherent manipulations of quantum systems.     

Mössbauer study of hyperfine structure of (bis-diethyldithiocarbamato)FeIIIBr

The parameters of nuclear hyperfine splittings for the paramagnet Fe(dtc)₂Br have been determined by Mössbauer measurements on a mixed system of this compound with the homologous ferromagnetic chloro derivative acting as host. The crystal field z axis is found to be perpendicular to the exchange field for Fe(dtc)₂Br, in contrast to the host.