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Bielefeld, Germany

Antoniadis V.,University of Thessaly | Shaheen S.M.,Kafr El Sheikh University | Shaheen S.M.,University of Wuppertal | Boersch J.,University of Wuppertal | And 5 more authors.
Journal of Environmental Management | Year: 2016

Although soil contamination by potentially toxic elements (PTEs) in Europe has a history of many centuries, related problems are often considered as having been dealt with due to the enforcement of tight legislations. However, there are many unsolved issues. We aimed to assess PTE levels in highly contaminated soils and in garden edible vegetables using human health risk indices in order to evaluate the availability and mobilization of arsenic (As), copper (Cu), manganese (Mn), mercury (Hg), lead (Pb), and zinc (Zn). In four gardens in Germany, situated on, or in the vicinity of, a mine dump area, we planted beans (Phaseolus vulgaris ssp. nanus), carrots (Daucus sativus) and lettuce (Lactuca sativa ssp. capitata). We examined soil-to-plant mobilization of elements using transfer coefficient (TC), as well as soil contamination using contamination factor (CF), enrichment factor (EF), and bioaccumulation index (I geo). In addition, we tested two human health risk assessment indices: Soil-induced hazard quotient (HQS) (representing the "direct soil ingestion" pathway), and vegetable-induced hazard quotient (HQV) (representing the "vegetable intake" pathway). The studied elements were highly elevated in the soils. The values in garden 2 were especially high (e.g., Pb: 13789.0 and Hg: 36.8 mg kg-1) and largely exceeded the reported regulation limits of 50 (for As), 40 (Cu), 400 (Pb), 150 (Zn), and 5 (Hg) mg kg-1. Similarly, element concentrations were very high in the grown vegetables. The indices of CF, EF and I geo were enhanced even to levels that are rarely reported in the literature. Specifically, garden 2 indicated severe contamination due to multi-element deposition. The contribution of each PTE to the total of measured HQS revealed that Pb was the single most important element causing health risk (contributing up to 77% to total HQS). Lead also posed the highest risk concerning vegetable consumption, contributing up to 77% to total HQV. The presence of lead in both cases was followed by that of As, Mn and Hg. We conclude that in multi-element contamination cases, along with high-toxicity elements (here, Pb, As and Hg) other elements may also be responsible for increasing human health risks (i.e., Mn), due to the possibility of adverse synergism of the PTEs. © 2016. Source


Burney S.,University Paris - Sud | Wenzel R.,Free University of Berlin | Kottke T.,Universitatsstrasse 25 | Roussel T.,University Paris - Sud | And 5 more authors.
Angewandte Chemie - International Edition | Year: 2012

A quick switch: A single amino acid substitution at a conserved residue (D396N) of Arabidopsis cryptochrome-1 (Atcry1) confers single-stranded DNA repair activity in vitro, conferring photolyase activity onto the cryptochrome (see graph). The mutant protein undergoes photoreduction of flavin to the fully reduced anionic form, similar to photolyases and unlike wild-type cryptochromes. © 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Lier F.,CITEC | Schulz S.,CITEC | Lutkebohle I.,Universitatsstrasse 25
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2012

Simulated environments often provide the first, and are usually the most frequent, test environment for robotic systems, primarily due to their cost and safety advantages. Unfortunately, changing aspects of both, the simulation and the real robot, as well as actuator control algorithms are often not taken into account when relying on simulation results. In this paper we present a continuous integration approach to verify simulated robot models in an integrated and frequent manner, comprising a simulated and a real robot for comparison. The central aspect of our concept is to iteratively assess the fidelity of simulated robot models. In an exemplary case study we distilled a first set of requirements and metrics, which can be used by developers to verify their algorithms and to automatically detect further system changes. © 2012 Springer-Verlag Berlin Heidelberg. Source


Kuck D.,Bielefeld University | Kuck D.,Universitatsstrasse 25 | Linke J.,Bielefeld University | Teichmann L.C.,Bielefeld University | And 6 more authors.
Physical Chemistry Chemical Physics | Year: 2016

The solid-state molecular structure of centrohexaindane (1), a unique hydrocarbon comprising six benzene rings clamped to each other in three dimensions around a neopentane core, and the molecular packing in crystals of 1·CHCl3 are reported. The molecular Td-symmetry and the Cartesian orientation of the six indane wings of 1 in the solid state have been confirmed. The course and limitation of electrophilic aromatic substitution of 1 are demonstrated for the case of nitration. Based on nitration experiments of a lower congener of 1, tribenzotriquinacene 5, the six-fold nitrofunctionalisation of 1 has been achieved in excellent yield, giving four constitutional isomers, two nonsymmetrical (14 and 17) and two C3-symmetrical ones (15 and 16), all of which contain one single nitro group in each of the six benzene rings. The relative yields of the four isomers (∼3:1:1:3) point to a random electrophilic attack of the electrophiles at the twelve formally equivalent outer positions of the aromatic periphery of 1, suggesting electronic independence of its six aromatic π-electron systems. In turn, the pronounced conformational rigidity of the centrohexacyclic framework of 1 enables the unequivocal structural identification of the isomeric hexanitrocentrohexaindanes 14-17 by 1H NMR spectroscopy. © 2016 the Owner Societies. Source


Lier F.,CITEC | Siepmann F.,CITEC | Paul-Stueve T.,CITEC | Wrede S.,Universitatsstrasse 25 | And 2 more authors.
ACM International Conference Proceeding Series | Year: 2012

Researchers and other knowledge workers frequently produce and use diverse research artefacts such as papers, data sets, experiment specifications, software, etc. In this, they are often faced with unclear relationships (e.g., which version of a software was in use for a particular paper), creating unnecessary work and potentially errors. Semantic web technologies can provide metadata as well as explicit, specific links between the artefacts. However, data acquisition and perceived utility are potential stumbling blocks for adoption. Therefore, we propose a system which is focused on integrating and augmenting existing data (thus protecting the existing investment), and examine it using an interactionoriented perspective, on users without semantic web experience. Specifically, we first study requirements of the target group and then present an exploratory study of managing research artefacts related to software-centric projects. The results confirm that diverse data sources are in common use, that re-using existing repositories is perceived as efficient (e.g., more convenient, shorter cycle time), and that the experimented aggregates are perceived as functionally relevant. Furthermore, the integration of quality assurance mechanisms, such as continuous integration, is perceived as beneficial, despite some added effort. Copyright 2012 ACM. Source

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