Special jordan pairs

There are some important Jordan pairs contained in the free associative pair, e.g. the free special Jordan pair and the Jordan pair of all symmetric elements under the reversal involution. We study the connection between these two Jordan pairs in the case when the ring of scalars contains ½.     

Charge transfer at biotic/abiotic interfaces in biological electrocatalysis

In this opinion paper, we discuss the charge transfer at biotic/abiotic interfaces in man-made and biological electrochemical systems. Specifically, we will first introduce the heterogeneous charge transfer at the bioelectrode interface, followed by the intramolecular change transfer in peptide and protein structures, and finally discuss the extracellular charge transfer in electrogenic microorganisms. In addition to discussion of charge transfer mechanisms and synthetic structures/scaffolds required for it, a particular focus will be given to novel experimental designs that are able to bring new concepts and boost mechanism understanding and applications development. There are also discussions on the combination of modern computational techniques and experimental characterizations.     

The determination of the linear alkylbenzene sulfonate isomers in water samples by gas-chromatography/mass spectrometry

A number of 20 compounds of linear alkylbenzene sulfonates (LASs) family were identified by electron impact mass spectrometry (EI-MS) in water samples collected from wastewater treatment plants (WWTP). This paper presents the mass spectra of 20 compounds, the proposed mechanism of formation of the diagnostic ions obtained by EI-MS and the distribution of individual isomers in water samples collected from compartments of WWTP. The individual isomers from four homolog series C(10)-, C(11)-, C(12)- and C(13)-LAS were analyzed as methyl derivatives.     

Establishing Drug Resistance in Microorganisms by Mass Spectrometry

A rapid method to determine drug resistance in bacteria based on mass spectrometry is presented. In it, a mass spectrum of an intact microorganism grown in drug-containing stable isotope-labeled media is compared with a mass spectrum of the intact microorganism grown in non-labeled media without the drug present. Drug resistance is determined by predicting characteristic mass shifts of one or more microorganism biomarkers using bioinformatics algorithms. Observing such characteristic mass shifts indicates that the microorganism is viable even in the presence of the drug, thus incorporating the isotopic label into characteristic biomarker molecules. The performance of the method is illustrated on the example of intact E. coli, grown in control (unlabeled) and ¹³C-labeled media, and analyzed by MALDI TOF MS. Algorithms for data analysis are presented as well.

Polymerization and self‐assembly of thermally responsive in‐chain functionalized double‐hydrophilic macromonomers

Double‐hydrophilic in‐chain functionalized macromonomers consisting of poly(N‐isopropylacrylamide) (PNIPAM) and poly(ethylene oxide) were prepared by a multistep procedure including esterification of PNIPAM monoester of maleic acid with α‐methoxy‐ω‐hydroxypolyoxyethylene or its amidation with α‐methoxy‐ω‐aminopolyoxyethylene. The polymerization of the macromonomers was carried out in aqueous solutions. The temperature was the key parameter controlling the polymerization process that was performed in the organized domains formed by the macromonomers below and above the phase transition temperature (T_tr). Polymacromonomers with higher degrees of polymerization were prepared at temperatures just below the T_tr. Static light scattering measurements on dilute aqueous solutions of thermally‐responsive macromonomers and their polymerization products demonstrated that they formed aggregates below the T_tr. Supramolecular structures with low density cores, formed by the polymacromonomers at room temperature, were imaged by SEM. Morphological tuning was achieved by varying both the composition of the copolymer and the concentration of the aqueous solution. The rheological behavior of the polymacromonomers in 25 wt % aqueous solution was compared to that of the respective macromonomers. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4720–4732, 2007     

Strong asymptotics for Krawtchouk polynomials

We determine the strong asymptotics for the class of Krawtchouk polynomials on the real line. We show how our strong asymptotics describes the limiting distribution of the zeros of the Krawtchouk polynomials.     

Production of Metabolites with Antioxidant and Emulsifying Properties by Antarctic Strain Sporobolomyces salmonicolor AL1

The Sporobolomyces salmonicolor AL₁ Antarctic strain was cultivated and two bioproducts were obtained: exopolysaccharide and biomass. The biologically active substances ergosterol, torularhodin, torulene, β-carotene and CoQ₁₀ were extracted from the biomass and were quantified as follows: ergosterol 5.2?±?0.2 mg/g, torularhodin 458.3?±?24.5 μg/g, torulene 273.7?±?14.5 μg/g, β-carotene 129.2?±?7.3 μg/g and coenzyme Q₁₀ (CoQ₁₀) 236.1?±?12.1 μg/g. Their antioxidant activity was estimated according to the cathode voltammetry method. The most pronounced antioxidant activity (according to trolox) was exhibited by β-carotene 3.78, followed by CoQ₁₀ 3.60, both of them being the main contributors to the total extract activity of 3.19. The biologically active metabolites in combination with exoglucomannan as emulsifier were used for the creation of model emulsion systems characterised by great stability. The absorption of UVA rays by the model emulsions was studied.     

Sharp upper bounds on the number of the scattering poles

We study the scattering poles of a compactly supported “black box” perturbations of the Laplacian in Rⁿ, n odd. We prove a sharp upper bound of the counting function N(r) modulo o(rⁿ) in terms of the counting function of the reference operator in the smallest ball around the black box. In the most interesting cases, we prove a bound of the type N(r)?A_nrⁿ+o(rⁿ) with an explicit A_n. We prove that this bound is sharp in a few special spherically symmetric cases where the bound turns into an asymptotic formula.     

The efficient evaluation of the hypergeometric function of a matrix argument

We present new algorithms that efficiently approximate the hypergeometric function of a matrix argument through its expansion as a series of Jack functions. Our algorithms exploit the combinatorial properties of the Jack function, and have complexity that is only linear in the size of the matrix.

     

Perturbation theory for the LDU factorization and accurate computations for diagonally dominant matrices

We present a structured perturbation theory for the LDU factorization of (row) diagonally dominant matrices and we use this theory to prove that a recent algorithm of Ye (Math Comp 77(264):2195–2230, 2008) computes the L, D and U factors of these matrices with relative errors less than 14n ³ u, where u is the unit roundoff and n × n is the size of the matrix. The relative errors for D are componentwise and for L and U are normwise with respect the “max norm” ||A||_M = max_ij |a_ij|{\|A\|_M = \max_{ij} |a_{ij}|}. These error bounds guarantee that for any diagonally dominant matrix A we can compute accurately its singular value decomposition and the solution of the linear system Ax = b for most vectors b, independently of the magnitude of the traditional condition number of A and in O(n ³) flops.