The Social Web Cockpit

The Social Web Cockpit integrates different services that have been developed in the Social Web research programme at GMD-FIT to support a knowledge sharing community. This includes a web-search based on recommendations, a concept index to develop a community vocabulary, shared workspaces for knowledge sharing, and an awareness service

Hanging off a bar

Exertion Games involve physical effort and as a result can facilitate physical health benefits. We present Hanging off a Bar, an action hero-inspired Exertion Game in which players hang off an exercise bar over a virtual river for as long as possible. Initial observations from three events with audiences ranging from the general public to expert game designers suggest that Hanging off a Bar can be engaging for players and facilitate intense exertion within seconds. Furthermore, we collected suggestions for what game elements players believe could entice them to increase their physical effort investment. These suggestions, combined with Hanging off a Bar as research vehicle due to the easy measurement of exertion through hanging time, enable future explorations into the relationship between digital game elements and physical exertion, guiding designers on how to support exertion in digital game

NMR Characterizations of the Ice Binding Surface of an Antifreeze Protein

Antifreeze protein (AFP) has a unique function of reducing solution freezing temperature to protect organisms from ice damage. However, its functional mechanism is not well understood. An intriguing question concerning AFP function is how the high selectivity for ice ligand is achieved in the presence of free water of much higher concentration which likely imposes a large kinetic barrier for protein-ice recognition. In this study, we explore this question by investigating the property of the ice binding surface of an antifreeze protein using NMR spectroscopy. An investigation of the temperature gradient of amide proton chemical shift and its correlation with chemical shift deviation from random coil was performed for CfAFP-501, a hyperactive insect AFP. A good correlation between the two parameters was observed for one of the two Thr rows on the ice binding surface. A significant temperature-dependent protein-solvent interaction is found to be the most probable origin for this correlation, which is consistent with a scenario of hydrophobic hydration on the ice binding surface. In accordance with this finding, rotational correlation time analyses combined with relaxation dispersion measurements reveals a weak dimer formation through ice binding surface at room temperature and a population shift of dimer to monomer at low temperature, suggesting hydrophobic effect involved in dimer formation and hence hydrophobic hydration on the ice binding surface of the protein. Our finding of hydrophobic hydration on the ice binding surface provides a test for existing simulation studies. The occurrence of hydrophobic hydration on the ice binding surface is likely unnecessary for enhancing protein-ice binding affinity which is achieved by a tight H-bonding network. Subsequently, we speculate that the hydrophobic hydration occurring on the ice binding surface plays a role in facilitating protein-ice recognition by lowering the kinetic barrier as suggested by some simulation studies

Lateral Transfer of a Lectin-Like Antifreeze Protein Gene in Fishes

Fishes living in icy seawater are usually protected from freezing by endogenous antifreeze proteins (AFPs) that bind to ice crystals and stop them from growing. The scattered distribution of five highly diverse AFP types across phylogenetically disparate fish species is puzzling. The appearance of radically different AFPs in closely related species has been attributed to the rapid, independent evolution of these proteins in response to natural selection caused by sea level glaciations within the last 20 million years. In at least one instance the same type of simple repetitive AFP has independently originated in two distant species by convergent evolution. But, the isolated occurrence of three very similar type II AFPs in three distantly related species (herring, smelt and sea raven) cannot be explained by this mechanism. These globular, lectin-like AFPs have a unique disulfide-bonding pattern, and share up to 85% identity in their amino acid sequences, with regions of even higher identity in their genes. A thorough search of current databases failed to find a homolog in any other species with greater than 40% amino acid sequence identity. Consistent with this result, genomic Southern blots showed the lectin-like AFP gene was absent from all other fish species tested. The remarkable conservation of both intron and exon sequences, the lack of correlation between evolutionary distance and mutation rate, and the pattern of silent vs non-silent codon changes make it unlikely that the gene for this AFP pre-existed but was lost from most branches of the teleost radiation. We propose instead that lateral gene transfer has resulted in the occurrence of the type II AFPs in herring, smelt and sea raven and allowed these species to survive in an otherwise lethal niche

FABEL Abschlussbericht des Projektleiters der GMD

State of the art are knowledge-based configuration systems. Case-based reasoners do not deal with technical drawings. The goal was to develop methods to support complex design processes with case-based and other knowledge-based reasoners. The approach was to define the notion of cases for technical plans, to develop suitable similarity concepts and a case base organisation that allows to combine similarity concepts dynamically. Approaches to structure adaptation were developed and agent-based design improvement and refiniment methods. An open software architecture was designed to integrate those tools. The result is an open system for the integration of independent case-based or knowledge-based tools with a special infrastructure for the management of case bases. Tools are available that allow to retrieve technical plans by example, to adapt them in a context-sensitive way, or to assess and refine plans. The results can be relevant for applications in CAAD, CADx, or GIS. (orig.)SIGLEAvailable from TIB Hannover: F96B1403+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Tryptophan residues in caldesmon are major determinants for calmodulin binding

the contribution of each of the three Trp residues in the calmodulin-caldesmon interaction, we have mutated the Trp residues to Ala in the COOH-terminal domain of fibroblast caldesmon (CaD39) and studied the effects on calmodulin binding by fluorescence measurements and using immobilized calmodulin. Wild-type CaD39 binds with a Kd of 0.13 × 10-6 M and a stoichiometry of 1 mol of calmodulin per mol of caldesmon. Replacing Trp 659 at site A or Trp 692 at site B to Ala reduces binding by 22- and 31-fold (Kd) 2.9 × 10-6 and 4.0 × 10-6 M), respectively, and destabilizes the CaD39-calmodulin complex by 1.75 and 1.94 kcal mol-1, respectively. Mutation of both Trp 659 and Trp 692 to Ala further reduces binding with a Kd of 6.1 × 10-6 M and destabilizes the complex by 2.17 kcal mol-1. On the other hand, mutation of Trp 722 at site B ′ to Ala causes a much smaller decrease in affinity (Kd) 0.6 × 10-6 M) and results in a destabilization energy of 0.87 kcal mol-1. To investigate the relative importance of the amino acid residues near each Trp residue in the caldesmon-calmodulin interaction, deletion mutants were constructed lacking site A, site B, and site A+B. Although deletion of site A decreases binding of CaD39 to calmodulin by 13-fold (Kd) 1.7 × 10-6 M), it results in tighter binding than mutation of Trp 659 to Ala at this site, suggesting that the residues neighboring Trp 659 may contribute negatively to the interaction. Deletion of site B causes a similar reduction in binding (Kd) 4.1 × 10-6 M) as observe

Reasoning with complex cases Preprint

SIGLEAvailable from TIB Hannover: F96B1804+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Fallverwaltung und Fallretrieval Implementierungen und Tests

SIGLEAvailable from TIB Hannover: RR 3215(7) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman