A Hierarchical Bayesian Trust Model based on Reputation and Group Behaviour

In many systems, agents must rely on their peers to achieve their goals. However, when trusted to perform an action, an agent may betray that trust by not behaving as required. Agents must therefore estimate the behaviour of their peers, so that they may identify reliable interaction partners. To this end, we present a Bayesian trust model (HABIT) for assessing trust based on direct experience and (potentially unreliable) reputation. Although existing approaches claim to achieve this, most rely on heuristics with little theoretical foundation. In contrast, HABIT is based on principled statistical techniques; can be used with any representation of behaviour; and can assess trust based on observed similarities between groups of agents. In this paper, we describe the theoretical aspects of the model and present experimental results in which HABIT was shown to be up to twice as accurate at predicting trustee performance as an existing state-of-the-art trust model

Der Wille zur Apokatastasis:Patristik und esoterisches Judentum in Walter Benjamins später theologischer Politik

Der Literatur- und Medienwissenschaftler Michael W. Jennings stellt in seinem Aufsatz die Bedeutung des theologischen Konzepts der apokatastasis in Benjamins Texten heraus, das sich auf Origines’ Lehre von der Wiederherstellung der Dinge am Ende der Zeiten bezieht. Nach Jennings basiert Benjamins Vorstellung, dass es in der Gegenwart noch keine Religion geben kann, auf der Überzeugung, dass die Bedingungen für die Möglichkeit von Religion erst nach dem Ende der Geschichte gegeben sind. In einem zweiten Schritt geht er den verborgenen Spuren des Konzepts der apokastastasis in Benjamins medientheoretischen Schriften nach. Er zeigt, wie die im Kunstwerk-Aufsatz artikulierte Hoffnung, dass die vom Kapitalismus deformierten Wahrnehmungsformen durch eine revolutionäre Veränderung der Wahrnehmung zerstört und durch eine neue Sicht auf die Welt ersetzt wird, auf die Idee der apokastasis zurückgeführt werden kann.Michael W. Jennings, »Der Wille zur Apokatastasis: Patristik und esoterisches Judentum in Walter Benjamins später theologischer Politik«, in Aura und Experiment: Naturwissenschaft und Technik bei Walter Benjamin, hg. v. Kyung-Ho Cha, Cultural Inquiry, 13 (Wien: Turia + Kant, 2017), S. 89–109 <https://doi.org/10.37050/ci-13_06

Cloning of the Lipooligosaccharide α-2,3-Sialyltransferase from the Bacterial Pathogens Neisseria meningitidis and Neisseria gonorrhoeae

The genes encoding the alpha-2,3-sialyltransferases involved in lipooligosaccharide biosynthesis from Neisseria meningitidis and Neisseria gonorrhoeae have been cloned and expressed in Escherichia coli. A high sensitivity enzyme assay using a synthetic fluorescent glycosyltransferase acceptor and capillary electrophoresis was used to screen a genomic library of N. meningitidis MC58 L3 in a "divide and conquer" strategy. The gene, denoted lst, was found on a 2. 0-kilobase fragment of DNA, and its sequence was determined and then used to design probes to amplify and subsequently clone the corresponding lst genes from N. meningitidis 406Y L3, N. meningitidis M982B L7, and N. gonorrhoeae F62. Functional sialyltransferase was produced from the genes derived from both L3 N. meningitidis strains and the N. gonorrhoeae F62. However, the N. meningitidis M982B L7 gene contained a frameshift mutation that renders it inactive. The expression of the lst gene was easily detected using the enzyme assay, and the protein expression could be detected when an immunodetection tag was added to the COOH-terminal end of the protein. Using the synthetic acceptor N-acetyllactosamine-aminophenyl-(6-(5-(fluorescein-carboxamido)-hexan oic acid amide), the alpha-2,3 specificity of the enzyme was confirmed by NMR examination of the reaction product. The enzyme could also use synthetic acceptors with lactose or galactose as the saccharide portion. This study is the first example of the cloning, expression, and examination of alpha-2,3-sialyltransferase activity from a bacterial source

Ferrets exclusively synthesize Neu5Ac and express naturally humanized influenza A virus receptors

Mammals express the sialic acids ​N-acetylneuraminic acid (​Neu5Ac) and ​N-glycolylneuraminic acid (​Neu5Gc) on cell surfaces, where they act as receptors for pathogens, including influenza A virus (IAV). ​Neu5Gc is synthesized from ​Neu5Ac by the enzyme cytidine monophosphate-N-acetylneuraminic acid hydroxylase (CMAH). In humans, this enzyme is inactive and only ​Neu5Ac is produced. Ferrets are susceptible to human-adapted IAV strains and have been the dominant animal model for IAV studies. Here we show that ferrets, like humans, do not synthesize ​Neu5Gc. Genomic analysis reveals an ancient, nine-exon deletion in the ferret CMAH gene that is shared by the Pinnipedia and Musteloidia members of the Carnivora. Interactions between two human strains of IAV with the sialyllactose receptor (sialic acid—α2,6Gal) confirm that the type of terminal sialic acid contributes significantly to IAV receptor specificity. Our results indicate that exclusive expression of ​Neu5Ac contributes to the susceptibility of ferrets to human-adapted IAV strains

Delivering services by building and running virtual organisations

Non peer reviewedPostprin