Leibniz University of Hanover

About: Leibniz University of Hanover is a education organization based out in Hanover, Niedersachsen, Germany. It is known for research contribution in the topics: Finite element method & Population. The organization has 14283 authors who have published 29845 publications receiving 682152 citations.

A Hierarchical Human-Robot Interaction-Planning Framework for Task Allocation in Collaborative Industrial Assembly Processes

Abstract: In this letter, we propose a framework for task allocation in human-robot collaborative assembly planning. Our framework distinguishes between two main layers of abstraction and allocation. In the higher layer, we use an abstract world model, incorporating a multiagent human-robot team approach in order to describe the collaborative assembly planning problem. From this, nominal co-ordinated skill sequences for every agent are produced. In order to be able to treat humans and robots as agents of the same form, we move relevant differences/peculiarities into distinct cost functions. The layer beneath handles the concrete skill execution. On atomic level, skills are composed of complex hierarchical and concurrent hybrid state machines, which in turn co-ordinate the real-time behavior of the robot. Their careful design allows to cope with unpredictable events also on decisional level without having to explicitly plan for them, instead one may rely also on manually designed skills. Such events are likely to happen in dynamic and potentially partially known environments, which is especially true in case of human presence.

Diet and psoriasis : Experimental data and clinical evidence

Abstract: Psoriasis is considered as a T-cell-mediated inflammatory skin disease which is characterized by hyperproliferation and poor differentiation of epidermal keratinocytes. While susceptibility to psoriasis is inherited, the disease is influenced by environmental factors such as infections and stress. Diet has been suggested to play a role in the aetiology and pathogenesis of psoriasis. Fasting periods, low-energy diets and vegetarian diets improved psoriasis symptoms in some studies, and diets rich in n-3 polyunsaturated fatty acids from fish oil also showed beneficial effects. All these diets modify the polyunsaturated fatty acid metabolism and influence the eicosanoid profile, so that inflammatory processes are suppressed. Some patients with psoriasis show an elevated sensitivity to gluten. In patients with IgA and/or IgG antigliadin antibodies the symptoms have been shown to improve on a gluten-free diet. The active form of vitamin D, 1,25-dihydroxyvitamin D(3), exhibits antiproliferative and immunoregulatory effects via the vitamin D receptor, and thus is successfully used in the topical treatment of psoriasis. In this review, dietary factors which play a role in psoriasis are assessed and their potential benefit is evaluated. Furthermore, the risk of drug-nutrient interactions in psoriasis therapy is discussed.

Metabolic costs of amino acid and protein production in Escherichia coli.

Abstract: Escherichia coli is the most popular microorganism for the production of recombinant proteins and is gaining increasing importance for the production of low-molecular weight compounds such as amino acids. The metabolic cost associated with the production of amino acids and (recombinant) proteins from glucose, glycerol and acetate was determined using three different computational techniques to identify those amino acids that put the highest burden on the biosynthetic machinery of E. coli. Comparing the costs of individual amino acids, we find that methionine is the most expensive amino acid in terms of consumed mol of ATP per molecule produced, while leucine is the most expensive amino acid when taking into account the cellular abundances of amino acids. Moreover, we show that the biosynthesis of a large number of amino acids from glucose and particularly from glycerol provides a surplus of energy, which can be used to balance the high energetic cost of amino acid polymerization.

The multi-protein family of Arabidopsis sulphotransferases and their relatives in other plant species

Abstract: All members of the sulphotransferase (SOT, EC 2.8.2.-) protein family use 39-phosphoadenosine 59-phosphosulphate (PAPS) as the sulphuryl donor and transfer the sulphonate group to an appropriate hydroxyl group of several classes of substrates. These enzymes have highly conserved domains and can be found in eubacteria and eukaryotes. In mammals, sulphate conjugation catalysed by SOTs constitutes an important reaction in the transformation of xenobiotics, and in the modulation of the biological activity of steroid hormones and neurotransmitters. In plants, sulphateconjugation reactions seem to play an important role in plant growth, development, and adaptation to stress. To date only a few plant SOTs have been characterized in detail. The flavonol 3- and 49-SOTs from Flaveria species (Asteraceae), which catalyse the sulphonation of flavonol aglycones and flavonol 3-sulphates, respectively, were the first plant SOTs for which cDNA clones were isolated. The plasma membrane associated gallic acid SOT of Mimosa pudica L. pulvini cells may be intrinsic to signalling events that modify the seismonastic response. In Brassica napus L. a SOT catalyses the O-sulphonation of brassinosteroids and thereby abolishes specifically the biological activity of 24-epibrassinolide. The fully sequenced genome of Arabidopsis thaliana Heynh. contains in total 18 genes that are likely to encode SOT proteins based on sequence similarities of the translated products with an average identity of 51.1%. So far only one SOT from A. thaliana (At5g07000) was functionally characterized: the protein was shown to catalyse the sulphonation of 12hydroxyjasmonate and thereby inactivate excess jasmonic acid in plants. The substrates and, therefore, the physiological roles of SOTs are very diverse. By using the numerous informative databases and methods available for the model plant A. thaliana, the elucidation of the functional role of the SOT protein family will be accelerated.