Multiobjective routing in multiservice MPLS networks with traffic splitting — A network flow approach

A multiobjective routing model for Multiprotocol Label Switching networks with multiple service types and traffic splitting is presented in this paper.The routing problem is formulated as a multiobjective mixed-integer program,where the considered objectives are the minimization of the bandwidth routing cost and the minimization of the load cost in the network links with a constraint on the maximal splitting of traffic trunks.Two different exact methods are developed for solving the formulated problem,one based on the classical constraint method and another based on a modified constraint method.Avery extensive experimental study,with results on network performance measures in various reference test networks and in randomly generated networks,is also presented and its results are discussed.     

Induced and heavy aggregation operators with distance measures

This paper introduces a new aggregation model by using induced and heavy aggregation operators in distances measures such as the Hamming distance. It is called the induced heavy ordered weighted averaging (OWA) distance (IHOWAD) operator. This paper studies some of its main properties and a wide range of particular cases such as the induced heavy OWA (IHOWA) operator, the induced OWA distance (IOWAD) operator and the heavy OWA distance (HOWAD) operator. This approach is generalized by using generalized and quasi-arithmetic means obtaining the induced generalized IHOWAD (IGHOWAD) operator and the Quasi-IHOWAD operator. An application of the new approach in a decision making problem regarding the selection of strategies is developed.     

Generalization of the linguistic aggregation operator and its application in decision making

A generalization of the linguistic aggregation functions (or operators) is presented by using generalized and quasiarithmetic means.Firstly,the linguistic weighted generalized mean (LWGM) and the linguistic generalized ordered weighted averaging (LGOWA) operator are introduced.These aggregation functions use linguistic information and generalized means in the weighted average (WA) and in the ordered weighted averaging (OWA) function.They are very useful for uncertain situations where the available information cannot be assessed with numerical values but it is possible to use linguistic assessments.These aggregation operators generalize a wide range of aggregation operators that use linguistic information such as the linguistic generalized mean (LGM),the linguistic OWA (LOWA) operator and the linguistic ordered weighted quadratic averaging (LOWQA) operator.We also introduce a further generalization by using quasi-arithmetic means instead of generalized means obtaining the quasi-LWA and the quasi-LOWA operator.Finally,we develop an application of the new approach where we analyze a decision making problem regarding the selection of strategies.     

A plant pathogen virulence factor inhibits the eukaryotic proteasome by a novel mechanism

Pathogenic bacteria often use effector molecules to increase virulence. In most cases, the mode of action of effectors remains unknown. Strains of Pseudomonas syringae pv. syringae (Pss) secrete syringolin A (SylA), a product of a mixed non-ribosomal peptide/polyketide synthetase, in planta. Here we identify SylA as a virulence factor because a SylA-negative mutant in Pss strain B728a obtained by gene disruption was markedly less virulent on its host, Phaseolus vulgaris (bean). We show that SylA irreversibly inhibits all three catalytic activities of eukaryotic proteasomes, thus adding proteasome inhibition to the repertoire of modes of action of virulence factors. The crystal structure of the yeast proteasome in complex with SylA revealed a novel mechanism of covalent binding to the catalytic subunits. Thus, SylA defines a new class of proteasome inhibitors that includes glidobactin A (GlbA), a structurally related compound from an unknown species of the order Burkholderiales, for which we demonstrate a similar proteasome inhibition mechanism. As proteasome inhibitors are a promising class of anti-tumour agents, the discovery of a novel family of inhibitory natural products, which we refer to as syrbactins, may also have implications for the development of anti-cancer drugs. Homologues of SylA and GlbA synthetase genes are found in some other pathogenic bacteria, including the human pathogen Burkholderia pseudomallei, the causative agent of melioidosis. It is thus possible that these bacteria are capable of producing proteasome inhibitors of the syrbactin class.     

Unusual magnetic order in the pseudogap region of the superconductor HgBa2CuO4+delta

The pseudogap region of the phase diagram is an important unsolved puzzle in the field of high-transition-temperature (high-T(c)) superconductivity, characterized by anomalous physical properties. There are open questions about the number of distinct phases and the possible presence of a quantum-critical point underneath the superconducting dome. The picture has remained unclear because there has not been conclusive evidence for a new type of order. Neutron scattering measurements for YBa(2)Cu(3)O(6+delta) (YBCO) resulted in contradictory claims of no and weak magnetic order, and the interpretation of muon spin relaxation measurements on YBCO and of circularly polarized photoemission experiments on Bi(2)Sr(2)CaCu(2)O(8+delta)(refs 12, 13) has been controversial. Here we use polarized neutron diffraction to demonstrate for the model superconductor HgBa(2)CuO(4+delta) (Hg1201) that the characteristic temperature T* marks the onset of an unusual magnetic order. Together with recent results for YBCO, this observation constitutes a demonstration of the universal existence of such a state. The findings appear to rule out theories that regard T* as a crossover temperature rather than a phase transition temperature. Instead, they are consistent with a variant of previously proposed charge-current-loop order that involves apical oxygen orbitals, and with the notion that many of the unusual properties arise from the presence of a quantum-critical point.