Experimentally Feasible Security Check for n-qubit Quantum Secret Sharing

In this article we present a general security strategy for quantum secret sharing (QSS) protocols based on the HBB scheme presented by Hillery, Bu\v{z}ek and Berthiaume [Phys. Rev A \textbf{59}, 1829 (1999)]. We focus on a generalization of the HBB protocol to $n$ communication parties thus including $n$-partite GHZ states. We show that the multipartite version of the HBB scheme is insecure in certain settings and impractical when going to large $n$. To provide security for such QSS schemes in general we use the framework presented by some of the authors [M. Huber, F. Minert, A. Gabriel, B. C. Hiesmayr, Phys. Rev. Lett. \textbf{104}, 210501 (2010)] to detect certain genuine $n$ partite entanglement between the communication parties. In particular, we present a simple inequality which tests the security.Comment: 5 pages, submitted to Phys. Rev.

Recognition of Host Proteins by Helicobacter Cysteine-Rich Protein C

Tetratricopeptide- and sel1-like repeat (SLR) proteins modulate various cellular activities, ranging from transcription regulation to cell-fate control. Helicobacter cysteine-rich proteins (Hcp) consist of several SLRs that are cross-linked by disulfide bridges and have been implicated in host/pathogen interactions. Using pull-down proteomics, several human proteins including Nek9, Hsp90, and Hsc71 have been identified as putative human interaction partners for HcpC. The interaction between the NimA-like protein kinase Nek9 and HcpC has been validated by ELISA and surface plasmon resonance. Recombinant Nek9 is recognized by HcpC with a dissociation constant in the lower micromolar range. This interaction is formed either directly between Nek9 and HcpC or via the formation of a complex with Hsc71. The HcpC homologue HcpA possesses no affinity for Nek9, suggesting that the reported interaction is rather specific for HcpC. These results are consistent with previous observations where Nek9 was targeted upon bacterial or viral invasion. However, further experiments will be required to show that the reported interactions also occur in viv

Die Glutamyl-tRNA Reduktase aus Escherichia coli: Rekombinante Produktion, Enzymmechanismus und biochemische Charakterisierung

Tetrapyrrole sind essentielle Bestandteile biologischer Systeme. Escherichia coli Glutamyl-tRNA Reduktase katalysiert im Rahmen der Tetrapyrrolbiosynthese die NADPH-abhängige Reduktion eines tRNA-gebundenen Glutamats zu Glutamat-1-semialdehyd. In der vorliegenden Arbeit gelang es erstmals das Enzym rekombinant bis zur apparenten Homogenität darzustellen. Es wurde eine spezifische Aktivität von 0.47 µmol min-1 mg-1 mit E. coli Glu-tRNA(Glu) als Substrat für das dimere Enyzm bestimmt. Der postulierte Enzymmechanismus wurde durch den direkten experimentellen Nachweis des zentralen Thioester-Zwischenproduktes bewiesen. Durch Mutagenesestudien konnte der hoch konservierte Cystein-Rest 50 als Nukleophil des aktiven Zentrums identifiziert werden. Durch kinetische Analysen mit den GluTR-Varianten R52Q und R52K in Kombination mit dem artifiziellen Substrat Gln-tRNA(Glu) konnte die zentrale Rolle von Arginin 52 für die richtige Positionierung des Substrates und für die Differenzierung zwischen Glutamat und Glutamin nachgewiesen werden. Der Vergleich von Enzymkinetiken mit in vitro synthetisierter, unmodifizierter Glu-tRNA(Glu) und modifizierter Glu-tRNA(Glu) zeigten, dass die posttranskriptionalen Modifikationen der tRNA keinen Einfluß auf die Erkennung durch die GluTR haben. Durch Co-Immunopräzipitationsstudien konnten direkte Protein-Protein-Wechselwirkungen von E. coli GluRS, GluTR und GSA-AM nachgewiesen werden.Tetrapyrrols are essential for life and therefore present in most biological systems. The first enzyme of tetrapyrrole biosynthesis, glutamyl-tRNA reductase, catalyzes the NADPH-dependent reduction of glutamyl-tRNA to glutamate-1-semialdehyde. In the present study the recombinant Escherichia coli enzyme was purified to apparent homogeneity for the first time. The dimeric enzyme showed a specific activity of 0.47 µmol min-1 mg-1 using E. coli Glu-tRNA(Glu) as substrate. The postulated enzymatic mechanism was proved by the trapping and detection of the central thioester intermediate. Mutagenesis studies identified the highly conserved Cys-50 as the active-site nucleophil. Kinetic analysis of the GluTR mutants R52Q and R52K in combination with the artificial substrate Gln-tRNA(Glu) revealed the central role of Arg-52 for the spatial arrangement of the substrate and the discrimination between glutamate and glutamine in the amino acid moiety of the aminoacyl-tRNA substrate. The comparison of enzyme kinetics with in vitro synthesized, unmodified Glu-tRNA(Glu) and fully modified Glu-tRNA(Glu) demonstrated that glutamyl-tRNA recognition by GluTR is independent of posttranscriptional modifications. Co-immunoprecipitation studies provided evidence for direct protein-protein interactions of E. coli GluRS, GluTR and GSA-AM

Micro Smart Micro-grid and Its Cyber Security Aspects in a Port Infrastructure

Maritime ports are intensive energy areas with a plenty of electrical systems that require an average power of many tens of megawatts (MW). Competitiveness, profits, reduction of pollution, reliability of operations, carbon emission trading are important energy related considerations for any port authority. Current technology allows the deployment of a local micro-grid of the size of tenths of MW, capable of islanded operation in case of emergency and to grant an increasing energy independency. Ownership of the grid permits a large flexibility on prices of energy sold inside the port, trading on local electric market and reduction of pollution. Renewable energy generation has a large impact on costs since features a low marginal cost. Unfortunately the smart grid is a critical asset within the port infrastructure and its intelligence is a high-level target for cyberattacks. Such attacks are often based on malicious software (malware), which makes use of a controlling entity on the network to coordinate and propagate. In this document, we will outline some features of a port smart grid and typical characteristics of cyber-attacks including potential ways to recognize it and suggestion for effective countermeasures

Proposal of \u3cem\u3eVibrionimonas magnilacihabitans\u3c/em\u3e gen. nov., sp. nov., a Curved Gram Negative Bacterium Isolated From Lake Michigan Water

A mesophilic bacterium appearing as curved rod-shaped cells was isolated from Lake Michigan water. It exhibited highest similarities with Sediminibacterium ginsengisoli DCY13T (94.4 %); Sediminibacterium salmoneum NJ-44T (93.6 %) and Hydrotalea flava CCUG 51397 T (93.1 %) while similarities with other recognized species were sym-homospermidine was the primary polyamine. The major cellular fatty acids were iso-C15 : 1G, iso-C15 : 0, iso-C16 : 0 3-OH and iso-C17 : 0 3-OH, with moderate amounts of iso-C16 : 0. The presence of glycolipids differentiated the novel strains from related genera. The DNA mol% G+C content of the type strain MU-2T was 45.2. Results for other phenotypic and molecular analyses indicated that strain MU-2T is a representative of a novel genus and species for which the name Vibrionimonas magnilacihabitans is proposed. The type strain is MU-2T ( = NRRL B-59231 = DSM 22423)