Bielefeld University

About: Bielefeld University is a education organization based out in Bielefeld, Nordrhein-Westfalen, Germany. It is known for research contribution in the topics: Population & Quantum chromodynamics. The organization has 10123 authors who have published 26576 publications receiving 728250 citations. The organization is also known as: University of Bielefeld & UNIVERSITAET BIELEFELD.

The 32-kilobase exp gene cluster of Rhizobium meliloti directing the biosynthesis of galactoglucan: genetic organization and properties of the encoded gene products.

Abstract: Proteins directing the biosynthesis of galactoglucan (exopolysaccharide II) in Rhizobium meliloti Rm2011 are encoded by the exp genes. Sequence analysis of a 32-kb DNA fragment of megaplasmid 2 containing the exp gene cluster identified previously (J. Glazebrook and G. C. Walker, Cell 56:661-672, 1989) revealed the presence of 25 open reading frames. Homologies of the deduced exp gene products to proteins of known function suggested that the exp genes encoded four proteins involved in the biosynthesis of dTDP-glucose and dTDP-rhamnose, six glycosyltransferases, an ABC transporter complex homologous to the subfamily of peptide and protein export complexes, and a protein homologous to Rhizobium NodO proteins. In addition, homologies of three Exp proteins to transcriptional regulators, methyltransferases, and periplasmic binding proteins were found. The positions of 26 Tn5 insertions in the exp gene cluster were determined, thus allowing the previously described genetic map to be correlated with the sequence. Operon analysis revealed that the exp gene cluster consists of five complementation groups. In comparison to the wild-type background, all exp complementation groups were transcribed at a substantially elevated level in the regulatory mucR mutant.

A symplectic QR like algorithm for the solution of the real algebraic Riccati equation

Abstract: A method is presented to solve the real algebraic Riccati equation - XNX + XA + A^{T}X + K = 0 , where K = K^{T} and N = N^{T} . The solution for the corresponding eigenvalue problem Mx = \lambda x , where M is a Hamiltonian matrix, is computed by an algorithm similar to the QR algorithm. Special symplectic matrices are used for the transformation of M such that the Hamiltonian form is preserved during the computations.

Dynamical systems on translation bounded measures: Pure point dynamical and diffraction spectra

Abstract: Certain topological dynamical systems are considered that arise from actions of $\sigma$-compact locally compact Abelian groups on compact spaces of translation bounded measures. Such a measure dynamical system is shown to have pure point dynamical spectrum if and only if its diffraction spectrum is pure point.

Bacteriochlorophyll g. A new bacteriochlorophyll from Heliobacterium chlorum

Abstract: A new bacteriochlorophyll g has been isolated from Heliobacterium chlorum. Its visible absorption spectrum is different from those of all other known bacteriochlorophylls, and it is extremely sensitive to oxygen in the presence of light. A proposal for the structure of the new bacteriochlorophyll g is given on the basis of absorption, CD, and 1H-NMR spectra of the corresponding bacteriopheophytin g and two main transformation products of Bchl g.