Dynamics of quantum dissipation systems interacting with bosonic canonical bath: Hierarchical equations of motion approach

A nonperturbative theory is developed, aiming at an exact and efficient evaluation of a general quantum system interacting with arbitrary bath environment at any temperature and in the presence of arbitrary time-dependent external fields. An exact hierarchical equations of motion formalism is constructed on the basis of calculus-on-path-integral algorithm, via the auxiliary influence generating functionals related to the interaction bath correlation functions in a parametrization expansion form. The corresponding continued-fraction Green's functions formalism for quantum dissipation is also presented. Proposed further is the principle of residue correction, not just for truncating the infinite hierarchy, but also for incorporating the small residue dissipation that may arise from the practical difference between the true and the parametrized bath correlation functions. The final residue-corrected hierarchical equations of motion can therefore be used practically for the evaluation of arbitrary dissipative quantum systems.Comment: 12 pages, submitted to PR

A new protocol for extraction of C0t-1 DNA from rice

C<i>0</i>t-1 DNA, enriched for repetitive DNA sequences, has been proved to be valuable in the studies of plant species differentiation and genome evolution. A new protocol to steadily obtain the aimed range of DNA fragments has been developed by shearing the genomic DNA with the digest system containing DNase and DNA polymerase . Comparison through fluorescence in situ hybridization (FISH) - Oryza sativa L with labeled probe of C0t-1 DNA isolated by the autoclave equipment and the new procedurewas carried out. FISH result shows that the new procedure can be a feasible method to steadily isolate high-quality C<i>0</i>t-1 DNA

Exact quantum dissipative dynamics under external time-dependent fields driving

Exact and nonperturbative quantum master equation can be constructed via the calculus on path integral. It results in hierarchical equations of motion for the reduced density operator. Involved are also a set of well--defined auxiliary density operators that resolve not just system--bath coupling strength but also memory. In this work, we scale these auxiliary operators individually to achieve a uniform error tolerance, as set by the reduced density operator. An efficient propagator is then proposed to the hierarchical Liouville--space dynamics of quantum dissipation. Numerically exact studies are carried out on the dephasing effect on population transfer in the simple stimulated Raman adiabatic passage scheme. We also make assessments on several perturbative theories for their applicabilities in the present system of study

CRISPR dynamics during the interaction between bacteria and phage in the first year of life

Gut microbiomes in infancy have a profound impact on health in adulthood. CRISPRs play an essential role in the interaction between bacteria and phages. However, the dynamics of CRISPRs in gut microbiomes during early life are poorly understood. In this study, using shotgun metagenomic sequencing data from 82 Swedish infants’ gut microbiomes, 1882 candidate CRISPRs were identified, and their dynamics were analysed. We found large-scale turnover of CRISPRs and their spacers during the first year of life. As well as changes in relative abundance of the bacteria containing CRISPR, acquisition, loss and mutation of spacers were observed within the same CRISPR array sampled over time. Accordingly, the inferred interaction network of bacteria and phage was distinct at different times. This research underpins CRISPR dynamics and their potential role in the interaction between bacteria and phage in early life

CRISPR dynamics during the interaction between bacteria and phage in the first year of life

Gut microbiomes in infancy have a profound impact on health in adulthood. CRISPRs play an essential role in the interaction between bacteria and phages. However, the dynamics of CRISPRs in gut microbiomes during early life are poorly understood. In this study, using shotgun metagenomic sequencing data from 82 Swedish infants' gut microbiomes, 1882 candidate CRISPRs were identified, and their dynamics were analysed. We found large-scale turnover of CRISPRs and their spacers during the first year of life. As well as changes in relative abundance of the bacteria containing CRISPR, acquisition, loss and mutation of spacers were observed within the same CRISPR array sampled over time. Accordingly, the inferred interaction network of bacteria and phage was distinct at different times. This research underpins CRISPR dynamics and their potential role in the interaction between bacteria and phage in early life.</p

Quantitative trait locus (QTL) analysis of pod related traits in different environments in soybean

Soybean is an important crop, whose most agronomic traits are quantitative inherited. Mapping of these quantitative trait loci in soybean genes is importance for various applications. A F2:15 RIL population containing 149 lines derived from a cross between Charleston as female and Dongnong 594 as male parent were used for mapping of the QTL of pod related traits. Three agronomic traits showing clear phenotypic variations between parents were investigated and relevant QTLs were analyzed with software WindowsQTL Cartographer V2.5. The pod related traits are podwall thickness, weight of podwall, and ratio of podwall to pod (weight to weight). A total of 67 QTLs were mapped for 3 agronomic traits. Some QTLs identified under all environments tend to be valuable for soybean molecular marker assistant breeding selection.Key words: Soybean, pod traits, QTL, different environments

Justifying top management pay in a transitional economy

We investigate some aspects of top management pay in China\u27s listed firms. We find positive pay and performance sensitivities and elasticities for top executives. In terms of magnitude, these sensitivities are similar to those reported in U.S. firms during the 1970s. However, the pay and performance relation is slightly weaker for firms located in less developed provinces. We also find that the pay disparities between top managers and employees are positively related to a firm\u27s performance. Thus, it appears that any deviation away from a manager-worker compensation norm has to be justified by superior firm performance. In additional analyses, we find that managers\u27 perquisites are not related to performance

Effect of Exchange-type Zero-bias Anomaly on Single Electron Tunnelling of Au Nanoparticles

Using cryogenic scanning tunnelling microscopy and scanning tunnelling spectroscopy we measured single electron tunnelling of isolated Au nanoparticles with 1.4 nm in radius. We observe that a gap {\Delta}V ~ 2e/C (C is the capacitance of the Au particle) around zero bias in the tunnelling conductance spectrum, followed by a series of discrete single electron tunnelling peaks with voltage widths of EC ~ e/C at both negative and positive bias. Experimental data are well explained by taking into account the effect of exchange interaction of electrons on the single electron tunnelling of Au nanoparticles. A tunnelling peak near zero-bias was suppressed by the exchange-type zero-bias anomaly, which results in the gap {\Delta}V ~ 2EC.Comment: 4pages, 3 figure

Parallel momentum distribution of the 28^{28}Si fragments from 29^{29}P

Distribution of the parallel momentum of $^{28}$Si fragments from the breakup of 30.7 MeV/nucleon $^{29}$P has been measured on C targets. The distribution has the FWHM with the value of 110.5 $\pm$ 23.5 MeV/c which is consistent quantitatively with Galuber model calculation assuming by a valence proton in $^{29}$P. The density distribution is also predicted by Skyrme-Hartree-Fock calculation. Results show that there might exist the proton-skin structure in $^{29}$P.Comment: 4 pages, 4 figure