Anti-Pattern Matching Modulo

International audienceNegation is intrinsic to human thinking and most of the time when searching for something, we base our patterns on both positive and negative conditions. In a previous work, we have extended the notion of term to the one of anti-term that may contain complement symbols. Matching such anti-terms against terms has the nice property of being unitary. Here we generalize the syntactic anti-pattern matching to anti-pattern matching modulo an arbitrary equational theory E, and we study the specific and practically very useful case of associativity, possibly with a unity (AU). To this end, based on the syntacticness of associativity, we present a rule-based associative matching algorithm, and we extend it to AU. This algorithm is then used to solve AU anti-pattern matching problems. This allows us to be generic enough so that for instance, the AllDiff standard predicate of constraint programming becomes simply expressible in this framework. AU anti-patterns are implemented in the Tom language and we show some examples of their usage

Neuraminidase and Hemagglutinin Matching Patterns of a Highly Pathogenic Avian and Two Pandemic H1N1 Influenza A Viruses

BACKGROUND: Influenza A virus displays strong reassortment characteristics, which enable it to achieve adaptation in human infection. Surveying the reassortment and virulence of novel viruses is important in the prevention and control of an influenza pandemic. Meanwhile, studying the mechanism of reassortment may accelerate the development of anti-influenza strategies. METHODOLOGY/PRINCIPAL FINDINGS: The hemagglutinin (HA) and neuraminidase (NA) matching patterns of two pandemic H1N1 viruses (the 1918 and current 2009 strains) and a highly pathogenic avian influenza A virus (H5N1) were studied using a pseudotyped particle (pp) system. Our data showed that four of the six chimeric HA/NA combinations could produce infectious pps, and that some of the chimeric pps had greater infectivity than did their ancestors, raising the possibility of reassortment among these viruses. The NA of H5N1 (A/Anhui/1/2005) could hardly reassort with the HAs of the two H1N1 viruses. Many biological characteristics of HA and NA, including infectivity, hemagglutinating ability, and NA activity, are dependent on their matching pattern. CONCLUSIONS/SIGNIFICANCE: Our data suggest the existence of an interaction between HA and NA, and the HA NA matching pattern is critical for valid viral reassortment

Spontaneous emission control in high-extraction efficiency plasmonic crystals

We experimentally and theoretically investigate exciton-field coupling for the surface plasmon polariton (SPP) in waveguide-confined (WC) anti-symmetric modes of hexagonal plasmonic crystals in InP-TiO-Au-TiO-Si heterostructures. The radiative decay time of the InP-based transverse magnetic (TM)-strained multi-quantum well (MQW) coupled to the SPP modes is observed to be 2.9-3.7 times shorter than that of a bare MQW wafer. Theoretically we find that 80 % of the enhanced PL is emitted into SPP modes, and 17 % of the enhanced luminescence is redirected into WC-anti-symmetric modes. In addition to the direct coupling of the excitons to the plasmonic modes, this demonstration is also useful for the development of high-temperature SPP lasers, the development of highly integrated photo-electrical devices, or miniaturized biosensors.Comment: Spontaneous emission control in high-extraction efficiency plasmonic crystal