Local density of states and superconducting gap in the iron chalcogenide superconductor Fe1+δ_{1+\delta}Se1−x_{1-x}Tex_{x} observed by scanning tunneling spectroscopy

We report on the first investigation of the quasiparticle local density of states and superconducting gap in the iron chalcogenide superconductor Fe$_{1+\delta}$Se$_{1-x}$Te$_{x}$ ($T_{\mathrm{c}} \sim 14$ K). The surface of a cleaved crystal revealed an atomic square lattice, superimposed on the inhomogeneous background, with a lattice constant of $\sim 3.8$ \AA without any reconstruction. Tunneling spectra measured at 4.2 K exhibit the superconducting gap, which completely disappears at 18 K, with a magnitude of $\sim 2.3$ meV, corresponding to $2\Delta / k_{\mathrm{B}}T_{\mathrm{c}}=3.8$.In stark contrast to the cuprate superconductors, the value of the observed superconducting gap is relatively homogeneous, following a sharp distribution with a small standard deviation of 0.23 meV. Conversely, the normal-state local density of states observed above $T_{\mathrm{c}}$ shows spatial variation over a wide energy range of more than 1 eV, probably due to the excess iron present in the crystal.Comment: 4 pages, 5 figure

Local Measurement of Microwave Response with Local Tunneling Spectra Using Near Field Microwave Microscopy

We have designed and built a near-field scanning microwave microscope, which has been used to measure the local microwave response and the local density-of-states (LDOS) in the area including the boundary between the gold deposited and the non-deposited region on highly-orientated pyrolytic graphite at a frequency of about 7.3 GHz. We have succeeded in measuring the spatial variation of both the LDOS and the surface resistance. It can be observed that the surface resistance in gold deposited region with the metallic tunneling spectra is smaller than that in the non-deposited region with the U-shaped tunneling spectra.Comment: 3 pages, 3 figures

Retinoblastoma and Its Binding Partner MSI1 Control Imprinting in Arabidopsis

Parental genomic imprinting causes preferential expression of one of the two parental alleles. In mammals, differential sex-dependent deposition of silencing DNA methylation marks during gametogenesis initiates a new cycle of imprinting. Parental genomic imprinting has been detected in plants and relies on DNA methylation by the methyltransferase MET1. However, in contrast to mammals, plant imprints are created by differential removal of silencing marks during gametogenesis. In Arabidopsis, DNA demethylation is mediated by the DNA glycosylase DEMETER (DME) causing activation of imprinted genes at the end of female gametogenesis. On the basis of genetic interactions, we show that in addition to DME, the plant homologs of the human Retinoblastoma (Rb) and its binding partner RbAp48 are required for the activation of the imprinted genes FIS2 and FWA. This Rb-dependent activation is mediated by direct transcriptional repression of MET1 during female gametogenesis. We have thus identified a new mechanism required for imprinting establishment, outlining a new role for the Retinoblastoma pathway, which may be conserved in mammals

Reliable Methods for Estimating Relative Vocal Tract Lengths From Formant Trajectories of Common Words

This paper describes reliable methods for estimating relative vocal tract lengths from speech signals. Two proposed methods are based on the simple principle that resonant frequencies in an acoustic tube are inversely proportional to the tube length in cases where the configuration is constant. We estimated the ratio between two speakers\u27 vocal tract lengths using first and second formant trajectories of the same words uttered by them. In the first method, which is referred to as "strict estimation method", we sought instances at which the gross structures of two vocal tracts are analogous by applying dynamic time-warping to formant-trajectories of common words that were uttered at different speeds. In those instances, which were found from among more than 100 common words by two speakers, an average formant ratio proved to be an excellent estimate (about /spl plusmn/0.1% in errors) for a reciprocal of the vocal tract length ratio. Next, we examined a simplified method for estimating those ratios using all corresponding points of two formant-trajectories: it is the "direct estimation method". Estimation errors in the direct estimation were evaluated to be about /spl plusmn/0.3% at equal utterance-speeds and /spl plusmn/2% at most, within 2.0 of the ratios of "fast" to "slow". Finally, we estimated relative vocal tract lengths for four Japanese speaker groups, whose members differed in terms of age and gender. Experimental results showed that the average vocal tract length of adult females and that of 7-10-year-old boys and girls are 21%, 27%, and 30%, respectively, shorter than adult males\u27

The Quality Control Assessment of Commercially Available Coenzyme Q10-Containing Dietary and Health Supplements in Japan

Coenzyme Q10 (CoQ10) has been widely commercially available in Japan as a dietary and health supplement since 2001 and is used for the prevention of lifestyle-related diseases induced by free radicals and aging. We evaluated CoQ10 supplements to ensure that these supplements can be used effectively and safely. Commercially available products were selected and assessed by the quality control tests specified in the Japanese Pharmacopoeia XV. When the disintegration time of CoQ10 supplements was measured, a few tested supplements did not completely disintegrate even after incubation in water for an hour at 37°C. In the content test, many samples were well controlled. However, a few supplements showed low recovery rates of CoQ10 as compared to manufacturer’s indicated contents. Among soft capsule and liquid supplements, the reduced form of CoQ10 (H2CoQ10), as well as the oxidized form, was detected by HPLC with electrochemical detector. The results for experimental formulated CoQ10 supplements demonstrated that H2CoQ10 was produced by the interaction of CoQ10 with vitamins E and/or C. From these results, we concluded that quality varied considerably among the many supplement brands containing CoQ10. Additionally, we also demonstrated that H2CoQ10 can be detected in some foods as well as in CoQ10 supplements

Comunidade de Colêmbolos em florestas decíduas e em plantações da conífera Cryptomeria japonica no Japão central

Collembolan communities in conifer plantations (Japanese cedar, Cryptomeria japonica) and secondary deciduous broad-leaved forests of varying ages were investigated to determine the extent to which forest conversion (broad-leaved to coniferous) affects the species richness and assemblage composition of Collembola in central Japan. Density and total species richness of Collembola not differed between the broad-leaved and cedar forests except immediately after clear-cutting. The amount of forest-floor organic matter was larger in cedar forests and positively correlated with the species richness of detritus feeders. Species richness of fungal feeders and sucking feeders positively correlated with the species richness of forest-floor plants. There was difference in collembolan species composition between the forest types. The age of the forests seemed to have only small importance for the collembolan community, except during the first four years after clear-cutting. The conversion to artificial cedar stands has not reduced the abundance or species richness of collembolan communities, but has affected community composition. Differences in species composition may be related to the ground floras.As comunidades de colÛmbolos nas plantaþ§es da conÝfera Cryptomeria japonica (cedro japonês) e florestas decíduas secundárias de várias idades foram investigadas para determinar até que ponto a conversão da floresta decídua em conífera afeta a riqueza das espécies e a composição das comunidades de colêmbolos no Japão central. A densidade e a riqueza total de espécies de Collembola não foram diferentes entre as florestas decíduas e de cedro, exceto imediatamente depois do corte raso. A quantidade de matéria orgânica acumulada no solo foi maior sob cedro e positivamente correlacionada com a riqueza de espécies de detritívoros. A riqueza de espécies de fungívoros e sugadores foi positivamente correlacionada à riqueza de espécies de plantas do estrato herbáceo da floresta. Houve diferença na composição das espécies de colêmbolos entre os tipos de floresta. A idade das florestas parece ter pouca importância para a comunidade de colêmbolos, exceto nos primeiros quatro anos após o corte raso. Concluiu-se que a conversão da floresta decídua em plantações de cedro japonês não causou diminuição na abundância e na riqueza das espécies das comunidades de colêmbolos, mas afetou a composição dessas comunidades. As diferenças na composição das espécies podem ser relacionadas ao desenvolvimento de plantas do estrato herbáceo da floresta