University of Paderborn

About: University of Paderborn is a education organization based out in Paderborn, Nordrhein-Westfalen, Germany. It is known for research contribution in the topics: Control reconfiguration & Software. The organization has 6684 authors who have published 16929 publications receiving 323154 citations.

Metallothioneins: zinc, cadmium, mercury, and copper thiolates and selenolates mimicking protein active site features--structural aspects and biological implications.

Abstract: Metallothioneins (MTs) define a superfamily of ubiquitous cysteine-rich low molecular weight proteins or polypeptides that contain polynuclear metalsulfur coordination sites formed by metal ions with d10 configuration. The most prominent characteristics of these biomolecules, which have been discovered as a cadmium and zinc containing protein in horse kidney by Margoshes and Vallee in 1957,1 are their extremely high metal and sulfur contents (up to 10% w/w). Although MTs have been known as long as about half a century, their precise physiological function is still under debate. According to Kägi and Schäffer, they are thought to play roles both in the intracellular fixation of the essential trace elements zinc and copper, in controlling the concentrations of the free ions of these elements, in regulating their flow to their cellular destinations, in neutralizing the harmful influences of exposure to toxic elements such as cadmium and mercury, and in the protection from a variety of stress conditions.2 More recently, it was concluded by Maret and Vallee that the long sought role of MT lies in the control of the cellular zinc distribution as a function of the energy state of the cell and not in the widely held belief that MT primarily scavenges radicals or detoxifies metals.3 As can be learned by these speculations, investigations directed to explore the structure and chemistry of metallothioneins in greater detail are extremely important taking into account that nature makes use of them as multipurpose proteins. Several reviews covering this issue are available in the literature.4 Today, MTs are known to occur in all animal phyla examined so far as well as in certain fungi, plants, and cyanobacteria. Characterized by a low molecular mass of 6.000-7.000 amu, by 20 totally conserved cysteines out of a total of 61 or 62 amino acid residues (according to ca. 30% by number), without aromatic amino acids such as tyrosine or histidine, the apoprotein from rat liver (thionein) is able to bind a total of seven equivalents of divalent metal ions with d10 configuration such as Zn2+ or Cd2+ in two noninteracting domains. After demetalation, these proteins can be loaded with up to six Cu1+ ions in each domain.5 * To whom correspondence should be addressed. (G.H.) Tel +495251-60-2494. Fax +49-5251-60-3423. E-mail biohenkel@ uni-paderborn.de. (B.K.) Tel +49-251-833-3131. Fax +49-251-8338366. E-mail krebs@uni-muenster.de. † Universität Paderborn. ‡ Universität Münster. 801 Chem. Rev. 2004, 104, 801−824

Observation of Atomlike Nitrogen in Nitrogen-Implanted Solid C60.

Abstract: A new paramagnetic defect in solid ${\mathrm{C}}_{60}$ was produced by nitrogen implantation in solid ${\mathrm{C}}_{60}$. The hyperfine splitting and the isotope effect unambiguously show that the paramagnetic center contains one nitrogen nucleus. The hyperfine interaction is isotropic, its value is comparable to that of the free nitrogen atom, and the spin of the electron system is $S\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}3/2$, as in atomic nitrogen. The complex responsible for this center is soluble in toluene and C${\mathrm{S}}_{2}$ and is stable. We suggest that the complex consists of nitrogen inside ${\mathrm{C}}_{60}$.

Chirality in Liquid Crystals

Abstract: Classroom Experiments with Chiral Liquid Crystals.- From a Chiral Molecule to a Chiral Anisotropic Phase.- Chemical Structures and Polymorphism.- Cholesteric Liquid Crystals: Defects and Topology.- Cholesteric Liquid Crystals: Optics, Electro-optics, and Photo-optics.- Blue Phases.- Smectic Liquid Crystals: Ferroelectric Properties and Electroclinic Effect.- Smectic Liquid Crystals: Antiferroelectric and Ferrielectric Phases.- Twist Grain Boundary Phases.- Columnar Liquid Crystals.- Some Aspects of Polymer Dispersed and Polymer Stabilized Chiral Liquid Crystals.- Chirality in Liquid Crystal Elastomers.- Phase Chirality of Micellar Lyotropic Liquid Crystals.- Traveling Phase Boundaries with the Broken Symmetries of Life.

A summary of the REVERB challenge: state-of-the-art and remaining challenges in reverberant speech processing research

Abstract: In recent years, substantial progress has been made in the field of reverberant speech signal processing, including both single- and multichannel dereverberation techniques and automatic speech recognition (ASR) techniques that are robust to reverberation. In this paper, we describe the REVERB challenge, which is an evaluation campaign that was designed to evaluate such speech enhancement (SE) and ASR techniques to reveal the state-of-the-art techniques and obtain new insights regarding potential future research directions. Even though most existing benchmark tasks and challenges for distant speech processing focus on the noise robustness issue and sometimes only on a single-channel scenario, a particular novelty of the REVERB challenge is that it is carefully designed to test robustness against reverberation, based on both real, single-channel, and multichannel recordings. This challenge attracted 27 papers, which represent 25 systems specifically designed for SE purposes and 49 systems specifically designed for ASR purposes. This paper describes the problems dealt within the challenge, provides an overview of the submitted systems, and scrutinizes them to clarify what current processing strategies appear effective in reverberant speech processing.