Non-Markovian decoherence: complete positivity and decomposition

In this work, the non-Markovian decoherence is considered in two ways. Firstly, an effective Hamiltonian approach is demonstrated to investigate the decoherence of a quantum system in a non-Markovian environment, in which complete positivity of the reduced dynamics is achieved. This method uses the notion of an effective environment, that is a subsystem of the environment that causes the decoherence. Secondly, the evolution of the system and environment is decomposed, thus partially illuminating how they would interact given that memory effects are allowed. It should be noted that beam splitters and rotators are sufficient to explain this decomposition.

A Tunable Split Resonator Method for Non-destructive Permittivity Characterization

The split cylinder resonator method is improved for nondestructive and accurate measurement for low permittivity materials at multiple frequency points. The dielectric constants of flat substrate materials are calculated based on a rigorous mode match analysis of the TE/sub 011/ mode. The loss tangent is also approximately calculated. The dielectric properties of two commercial substrates have been measured at multiple frequencies. The results demonstrate that this technology is capable of accurately characterizing the dielectric properties of flat substrate materials versus frequency in a nondestructive way.

A split-combination approach to merging knowledge bases in possibilistic logic

In this paper, we propose an adaptive approach to merging possibilistic knowledge bases that deploys multiple operators instead of a single operator in the merging process. The merging approach consists of two steps: one is called the splitting step and the other is called the combination step. The splitting step splits each knowledge base into two subbases and then in the second step, different classes of subbases are combined using different operators. Our approach is applied to knowledge bases which are self-consistent and the result of merging is also a consistent knowledge base. Two operators are proposed based on two different splitting methods. Both operators result in a possibilistic knowledge base which contains more information than that obtained by the t-conorm (such as the maximum) based merging methods. In the flat case, one of the operators provides a good alternative to syntax-based merging operators in classical logic.

Detection and localisation of protein-protein interactions in Saccharomyces cerevisiae using a split-GFP method

An alternative method for monitoring protein-protein interactions in Saccharomyces cerevisiae has been developed. It relies on the ability of two fragments of enhanced green fluorescent protein (EGFP) to reassemble and fluoresce when fused to interacting proteins. Since this fluorescence can be detected in living cells, simultaneous detection and localisation of interacting pairs is possible. DNA sequences encoding N- and C-terminal EGFP fragments flanked by sequences from the genes of interest were transformed into S. cerevisicie JPY5 cells and homologous recombination into the genome verified by PCR. The system was evaluated by testing known interacting proteins: labelling of the phosphofructokinase subunits, Pfk1p and Pfk2p, with N- and C-terminal EGFP fragments, respectively, resulted in green fluorescence in the cytoplasm. The system works in other cellular compartments: labelling of Idh1p and Idh2p, (mitochondrial matrix), Sdh3p and Sdh4p (mitochondrial membrane) and Pap2p and Mtr4p (nucleus) all resulted in fluorescence in the appropriate cellular compartment. (c) 2008 Elsevier Inc. All rights reserved.