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.

From serendipity to design of polyoxometalates at the nanoscale, aesthetic beauty and applications

Abstract: Polyoxometalate cluster science has come a long way since the first description of molybdenum blue in 1778 by the famous Swedish chemist Scheele. Interestingly, it was considered as an extremely exciting discovery even at that time as the corresponding paper was translated from the Swedish into French and included under the title ‘‘Sur la Mine de Plomb ou Molybdène’’ in the series of ‘‘Observations sur la Physique, sur l’Histoire Naturelle et sur les Arts’’ by M. L’Abbé Rozier and M. J. A. Mongez le jeune, which collected important scientific publications of the time. Some time later, in 1826, Berzelius described the yellow precipitate that is produced when ammonium molybdate is added in excess to phosphoric acid, which is now known as the textbook example (NH4)3[PMo12O40]aq. Since this time the advances have been growing at an ever increasing rate. Polyoxometalates, a class of soluble metal oxides occupying a middle region between the monomeric metalates and the infinite metal-oxides, span a wide range of size, nuclearity, composition and physical properties that is quite breathtaking. In addition, the related research is highly interdisciplinary. The developments in polyoxometalate chemistry have been particularly remarkable and rapid since the early 1980s, facilitated by developments in instrumental analytics, and characterized by the explosion in published structural data whereby many hundreds, if not thousands, of new polyoxometalate clusters are added to the literature every year. So, what represents the state of the art, and what are the options for the future? This themed issue of Chemical Society Reviews dedicated to Polyoxometalate Cluster Science answers these questions a School of Chemistry, WestCHEM, University of Glasgow, Glasgow, G12 8QQ, UK. E-mail: lee.cronin@glasgow.ac.uk b Fakultät für Chemie, Universität Bielefeld, Postfach 100131, 33501 Bielefeld, Germany. E-mail: a.mueller@uni-bielefeld.de w Part of a themed issue covering the latest developments in polyoxometalate science.

Reduze 2 - Distributed Feynman Integral Reduction

Abstract: Reduze is a computer program for reducing Feynman integrals to master integrals employing a variant of Laporta's reduction algorithm. This article describes version 2 of the program. New features include the distributed reduction of single topologies on multiple processor cores. The parallel reduction of different topologies is supported via a modular, load balancing job system. Fast graph and matroid based algorithms allow for the identification of equivalent topologies and integrals.

Elimination of correlation in random codes for arbitrarily varying channels

Abstract: The author determines for arbitrarily varying channels a) the average error capacity and b) the maximal error capacity in case of randomized encoding.

Updating benchtop sequencing performance comparison

Abstract: In April 2012, your journal published a study by Loman et al.1 that systematically compared desktop next-generation sequencers (NGS) from three instrument providers. Using the custom scripts supplied by the authors, the same software and the same draft genome (with 153 remaining gaps within several scaffolds) as the reference, we reproduced their results with their data of the enterohemorrhagic Escherichia coli (EHEC) strain found in the 2011 outbreak in Germany. However, we wish to bring readers’ attention to some shortcomings in the report from Loman et al.1, focusing particularly on its discussion of read-level error analysis. NGS is a rapidly changing market, which clearly complicates the comparisons such as that made by Loman et al. Since the original study1, Illumina (San Diego) has launched the MiSeq sequencer officially and has released Nextera library construction kits and 2 × 250–base-pair (250-bp) paired-end (PE) sequencing chemistry. Furthermore, Life Technologies (Carlsbad, California), has made 200-bp and 300-bp kits available for the Ion Torrent Personal Genome Machine (PGM). Roche (Basel, Switzerland) has updated the Sequencing System software for its 454 GS Junior (GSJ) from version 2.6 to 2.7. In this report, we provide an up-to-date snapshot of how benchtop platforms have evolved since the previous study1.

Molecular growth from a Mo 176 to a Mo 248 cluster

Abstract: In polyoxometalate chemistry a large variety of compounds, clusters and solid-state structures can be formed by the linking together of well-defined metal–oxygen building blocks1, 2. These species exhibit unusual topological and electronic properties, andfind applications ranging from medicine3 to industrial processes4. The recently reported ring-shaped mixed-valence polyoxomolybdates of the type {Mo154} (refs 5, 6) and {Mo176} (refs 7, 8) represent a new class of giant clusters with nanometre-sized cavities and interesting properties for host–guest chemistry. Here we describe the formation of related clusters of the type {Mo248} formed by addition of further units to the inner surface of the {Mo176} ‘wheel’. The additional units arrange themselves into two {Mo36} ‘hub-caps’ on the initial wheel—clusters that are not stable in isolation. These findings reveal a new pathway to the development of complex coordination clusters.