Weak dipole moment of τ\tau in e+e−e^+e^- collisions with longitudinally polarized electrons

It is pointed out that certain CP-odd momentum correlations in the production and subsequent decay of tau pairs in $e^+e^-$ collisions get enhanced when the $e^-$ is longitudinally polarized. Analytic expressions for these correlations are obtained for the single-pion decay mode of $\tau$ when $\tau^+\tau^-$ have a ``weak" dipole form factor (WDFF) coupling to $Z$ . For $e^+e^-$ collisions at the $Z$ peak, a sensitivity of about 1-5$\times 10^{-17}$\mbox{$e$ cm} for the $\tau$ WDFF can be reached using a {\em single} $\tau^+\tau^-$ decay channel, with $10^6\, Z$'s likely to be available at the SLC at Stanford with $e^-$ polarization of 62\%-75\%.Comment: 9 pages, Latex, PRL-TH-93/17 (Revised

Techniques for the Synthesis of Reversible Toffoli Networks

This paper presents novel techniques for the synthesis of reversible networks of Toffoli gates, as well as improvements to previous methods. Gate count and technology oriented cost metrics are used. Our synthesis techniques are independent of the cost metrics. Two new iterative synthesis procedure employing Reed-Muller spectra are introduced and shown to complement earlier synthesis approaches. The template simplification suggested in earlier work is enhanced through introduction of a faster and more efficient template application algorithm, updated (shorter) classification of the templates, and presentation of the new templates of sizes 7 and 9. A novel ``resynthesis'' approach is introduced wherein a sequence of gates is chosen from a network, and the reversible specification it realizes is resynthesized as an independent problem in hopes of reducing the network cost. Empirical results are presented to show that the methods are effective both in terms of the realization of all 3x3 reversible functions and larger reversible benchmark specifications.Comment: 20 pages, 5 figure

Orbital symmetry fingerprints for magnetic adatoms in graphene

In this paper, we describe the formation of local resonances in graphene in the presence of magnetic adatoms containing localized orbitals of arbitrary symmetry, corresponding to any given angular momentum state. We show that quantum interference effects which are naturally inbuilt in the honeycomb lattice in combination with the specific orbital symmetry of the localized state lead to the formation of fingerprints in differential conductance curves. In the presence of Jahn-Teller distortion effects, which lift the orbital degeneracy of the adatoms, the orbital symmetries can lead to distinctive signatures in the local density of states. We show that those effects allow scanning tunneling probes to characterize adatoms and defects in graphene.Comment: 15 pages, 11 figures. Added discussion about the multi-orbital case and the validity of the single orbital picture. Published versio

Rhizosphere microbial community composition of common beans with different levels of resistance to Fusarium oxysporum.

Microbial communities in the rhizosphere make significant contributions to plant health, growth and protection against soil pathogens. Plants can take advantage of their rhizosphere microbiomes to fend off pathogens, avoiding microbial infections. Here, we aimed to identify potential microbial groups and functional traits correlated to the suppression of the soil borne Microbial diversity and functioning in the soil ecosystem 145 pathogen Fusarium oxysporum. Through shotgun metagenomics we investigated the rhizosphere microbial communities of four common bean cultivars with different levels of resistance to the fungus, ranging from susceptible to resistant. Plants were grown in mesocosms experiments with two contrasting soils, i.e. Amazon Dark Earth (ADE) and an agricultural soil (AS). The soils presented clear differences in chemical properties, and ADE hosts higher microbial diversity than AS. Chemical analysis indicated a significant increase of pH, Ca, Fe, sum of bases and base saturation, and decrease of K, Mg, exchangeable Al, and Mn in rhizosphere of both soil types. Quantitative PCR showed an increase of 16S rRNA copy number with the increase resistance to the fungus in ADE soil. The rhizosphere of the four bean cultivars is dominated by the same bacterial phyla Proteobacteria, Actinobacteria, Firmicutes, and Chloroflexi, albeit in different relative abundance between soil types. The community structure of rhizosphere was different from the bulk soil, revealing the selection process in this environment. In ADE soil, the most resistant cultivar presented higher taxonomic diversity when compared to other cultivars; in contrast, the functional diversity was lower. Comparing the resistant to the susceptible cultivars there was an increase of Nitrospirae, Solibacteres, Spirochaeta and Chryosiogenetes bacterial classes in the resistant. Also, resistant cultivar presented high number of sequences affiliated to the family Pseudomonadaceae and to the genera Bacillus and Solibacter. Interestingly, the resistant and moderately resistant cultivars, presented high proportion of sequences related to bacteriocin, a narrow spectrum antibiotic, which suggests its role on pathogen suppression. Preliminary analysis showed that the selection of the microbial communities inhabiting the common bean rhizosphere is cultivar and soil type dependent. Further analysis will search for bacterial groups potentially related to the fungal antagonism. FAPESP 2014/03217-3

Analysis of the rhizosphere microbial communities of common beans resistant and susceptible to Fusarium oxysporum.

The rhizosphere is the narrow zone of soil around the living plant roots that is influenced by the activity of the plants. Many beneficial microorganisms in the rhizosphere provide plants with mineral nutrients, phytohormones, and also help to protect the plant against soil-borne pathogens. Microbiological studies are addressed to understand how rhizosphere microorganisms are recruited from soil and either benefit or harm plant growth, nutrition and health. Here, we aimed to identify potential microbial groups and functional traits correlated to the suppression of the soil borne pathogen Fusarium oxysporum, the causal agent of Fusarium wilt on common beans. We used shotgun metagenomics to investigate the rhizosphere microbiome of two common bean cultivars classified as resistant (Milênio) and susceptible (Alvorada). Plants were grown in mesocosms experiments in Amazon Dark Earth, a soil with high microbial diversity. Chemical analysis indicated a significant increase of pH, Ca, Fe, Zn, Mn, B, nitrate, cation exchange capacity, sum of bases and base saturation in rhizosphere of both common bean types. The microbial community structure of rhizosphere was different from the bulk soil in a deeper taxonomic classification (genera), revealing the selection process in this environment. Quantitative PCR showed an increase of 16S rRNA copy number with the increase resistance to the fungus in ADE soil. The resistant cultivar presented higher taxonomic diversity but lower functional diversity. The most abundant phyla in rhizosphere were Proteobacteria (41%), Actinobacteria (31%), Firmicutes (5%), Acidobacteria (3%) and Chloroflexi (3%). The resistant cultivar presented more abundance of the phyla Chlamydiae, Spirochaetes, Deinococcus-Thermus and Chrysiogenetes in comparison to the susceptible one and bulk soil. Comparing the resistant to the susceptible cultivar in a finer taxonomic level, 24 genera presented higher abundance in the resistant one, highlighting Bacillus and Pseudomonas. Preliminary analysis showed that there is a specific selection of the microbial communities inhabiting the rhizosphere of a resistant common bean cultivar. Further analysis will combine 16S rRNA gene sequencing and metatranscriptome for a deep taxonomical and functional analysis

Ultimate on-chip quantum amplifier

We report amplification of electromagnetic waves by a single artificial atom in open 1D space. Our three-level artificial atom -- a superconducting quantum circuit -- coupled to a transmission line presents an analog of a natural atom in open space. The system is the most fundamental quantum amplifier whose gain is limited by a spontaneous emission mechanism. The noise performance is determined by the quantum noise revealed in the spectrum of spontaneous emission, also characterized in our experiments.Comment: 4 pages, 4 figures + supplemenntary materials accepted for publication in Phys. Rev. Lett