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Zizina emelina (de l'Orza) is listed on Japan's Red Data List as an endangered species because of loss of its principal food plant and habitat. We compared parts of the mitochondrial and nuclear genes of this species to investigate the level of genetic differentiation among the 14 extant populations. We also examined infection of the butterfly with the bacterium Wolbachia to clarify the bacterium's effects on the host population's genetic structure. Mitochondrial and nuclear DNA analyses revealed that haplotype composition differed significantly among most of the populations, and the fixation index FST was positively correlated with geographic distance. In addition, we found three strains of Wolbachia, one of which was a male killer; these strains were prevalent in several populations. There was linkage between some host mitochondrial haplotypes and the three Wolbachia strains, although no significant differences were found in a comparison of host mitochondrial genetic diversity with nuclear genetic diversity in Wolbachia-infected or -uninfected populations. These genetic analyses and Wolbachia infection findings show that Z. emelina has little migratory activity and that little gene flow occurs among the current populations.
It is difficult to get a real scale image of the solar system through lecture. A scale model is a classical and one of good solutions (e.g. Handa et al.2003, Handa et al.2008). Through this model, people living in or visiting to the city can physically understand the scale of the solar system. This scale gives 1 cm for Earth's diameter and 115 m for 1 AU. However, some gadget is required to make it attractive for public citizens.
Mango (Mangifera indica L.) is an important fruit crop with a long cultivation history in Myanmar. This study evaluated the genetic variation within two economically important traditional varieties, ‘Yin Kwe’ and ‘Sein Ta Lone’, and the relationship between genetic variation and propagation practices. Genetic variation was estimated by genotyping 94 individuals with 12 single sequence repeat markers. ‘Yin Kwe’ (n = 53) showed higher levels of observed heterozygosity (Ho = 0.59) and average genetic distance among individuals (Da = 0.29) than did ‘Sein Ta Lone’ (n = 41; Ho = 0.45; Da = 0.09). The differences between the two varieties at the DNA level were significant (Fst = 0.44). The broader genetic background in ‘Yin Kwe’ compared with ‘Sein Ta Lone’ was also demonstrated by neighbour-joining and principal coordinates analyses. Differences in variety uses and propagation practices were determined by interviewing local specialists in Lower Myanmar (southern Myanmar). ‘Yin Kwe’ was often used as a rootstock for ‘Sein Ta Lone’. Clonal propagation by grafting was observed frequently for ‘Sein Ta Lone’ but never for ‘Yin Kwe’. The differences in genetic variation between these two varieties might have been caused by the propagation practices for each variety, which result from their respective uses.
For appropriate safety assessment of TRU waste disposal, the dominant chemical species of 14C-gas was studied. [1,2-14C] sodium acetate was added to flooded paddy soil samples, and the content of 14C in the soil, solution, and the emitted CO2 gas during incubation period was determined. Recovery ratios of the total 14C activity to the initial 14C activity were 97.9% at day 1, 86.4% at day 3, and 83.5% at day 7 of incubation. The result of the day 1 means that the emitted 14C-gas was almost 14CO2. At day 7 of incubation, about 16.5% of 14C was failed to recover. Even if the unknown 14C was gases other than 14CO2, the dominant chemical species of the emitted 14C-gas will be 14CO2, because the recovery ratio of the 14CO2 was 48.9% (¿16.5%). Sodium 2-bromoethane-sulfonate was used to ensure the emission of CH4, but there was no effect of the regent to the recovery ratio of 14CO2. Methane emission may be little under our experimental conditions. These results suggest that the dominant chemical species of the emitted 14C-gas from the flooded paddy soil samples was 14CO2.
For appropriate safety assessment of TRU waste disposal, gasification ratios and distribution coefficients (Kd) of 14C labeled [1, 2-14C] sodium acetate were determined by batch experiments for a Japanese paddy soil sample. Approximately 60% of the total added C-14 was released from the flooded paddy soil into the air as gas forms during 7 days shake-incubation periods. In the present study, the paddy soil was contacted with deionized water and well water, and the lower gasification ratio was found for the well water sample. The similar result was observed for the Kd values. Values of Kd varied from 51 to 138 mL g-1. The lower values were observed when the soil was contacted with well water. When the microorganisms in the samples were killed by glutaraldehyde, both gasification ratios and Kd values were nearly zero. These results suggested that microorganisms responsible for the behavior of C-14 in biosphere. In addition, water characteristics such as dissolved ions, pH and electrical conductivity would affect the gasification ratio and the Kd values.
This paper summarizes research activities in National Institute of Radiological Sciences (NIRS) for evaluation of the radiation effects on selected terrestrial and aquatic organisms as well as the ecosystems. Seven organisms, conifers, fungi, earthworms, springtails, algae, daphnia and Medaka are presently selected to study. For the estimation of possible radiation dose, transfers of radionuclides and related elements from medium to organisms are evaluated. Dose-effect relationships of acute gamma radiation on the survival, growth, and reproduction of selected organisms have been studied. Studies on the effect of chronic gamma radiation at low dose rate were also started. In order to understand the mechanism of radiation effects and to find possible indicators of the effects, information of genome- and metagenome-wide gene expression has been collected. Evaluation of ecological effects of radiation is more challenging task. Study methods by using three-species microcosm were established, and an index for the holistic evaluation of effects on various ecological parameters was proposed. The microcosm has been simulated as a computer simulation code. Developments of more complicated and practical model ecosystems have been started. The Denaturant Gradient Gel Electrophoresis (DGGE) has been applied on soil bacterial community in order to evaluate the radiation effects on soil ecosystems.
Structural relaxation around free volume in Zr50Cu40Al10 bulk metallic glass (BMG) during isothermal annealing at 473, 573 and 673 K which are below glass transition temperature Tg =675 K have been investigated by positron annihilation lifetime (PAL) and coincidence Doppler broadening (CDB) measurements. The trends of change in positron lifetime, which correspond to the size of free volume at each annealing temperature, have a good correlation with their density change. These annealing processes obey a stretched exponential relaxation function (KWW: Kohlrausch-Williams-Watts law). Fitting parameters of KWW function, with relaxation time t0 and β, in each temperature were determined. These relaxation parameters depend on the annealing temperature, suggesting the distribution of activation energy for structural relaxation. Moreover, the profile of electron momentum distribution around free volume derived by CDB spectrum during annealing showed no appreciable change at each temperature. These facts suggest that long range chemical ordering, particularly around the free volume, dose not take place essentially.
Mathematical computer model is developed to simulate the population dynamics and dynamic mass budgets of the microbial community realized as a self sustainable aquatic ecological system in the tube. Autotroph algae, heterotroph protozoa and saprotroph bacteria live symbiotically with interspecies' interactions as predator-prey relationship, competition for the common resource, autolysis of detritus and detritus-grazing food chain, etc. The simulation model is the individual-based parallel model, built in the demographic stochasticity, environmental stochasticity by dividing the aquatic environment into patches.
Validity of the model is checked by the multifaceted data of the microcosm experiments. In the analysis, intrinsic parameters of umbrella endpoint regarding to lethality are manipulated at the individual level, and tried to find the population level, community level especially focused on predator-prey relationship, and revealed the indirect effect of chronic exposure of radiation on the probability of Tetrahymena's extinction.
In various organic electronic devices, interfaces formed by organic layers can play important roles. We have been studying various organic interfaces for clarifying their structure and electronic structure. In this talk, we will report our recent study of the effect of various types of doping for a variety of dopants – residual impurity, atmospheric gases, and metallic and organic intentional dopants. In particular, detailed and quantitative information about the effect of oxygen from the viewpoint of electronic structure was obtained for titanyl phthalocyanine (TiOPc), and the results corresponded well with the recent report of atmospheric effect on orga nic field effect transistor.
The heat-treatment retention time effect of carbonized polyvinylidenechloride (PVDC) was investigated. Homogeneous PVDC with a crystallite size of 267 Å was used as a precursor material for an electric double-layer capacitor electrode. The P-120m material, which was heat treated for 120 min at 700 °C, shows a larger specific capacitance than any other material in this study. It shows the largest values reported up to now, reaching values as high as 100.2 F/g for a two-electrode system, which is equivalent to 400.8 F/g in a conventional three-compartment electrode system. It is difficult to distinguish the difference in the pore-size distribution by way of gas adsorption as the retention time is varied. However, the difference can be clarified using a novel method based on the analysis of transmission electron microscopy images. As the retention time for heat treatment increases, the pore size grows through the coalescence of small pores. Furthermore, a new concept for the electric double-layer capacitance is suggested on the basis of analysis of the transmission electron microscopy observations.
Unsteady circular jets are treated experimentally and numerically. The time evolution
of circular pulse jets is investigated systematically for a wide range of jet strength,
with the focus on the jet evolution, in particular the formation processes of Mach
disks in the middle stage and of shock-cell structures in the later stage. It is shown
that unsteady second shocks are realized for all sonic underexpanded jets and they
either breed conical shocks for lower pressure ratios or truncated cones (Mach disk
and reflected shock) for higher pressure ratios. The vortex ring produced near the
nozzle lip plays an important role in the formation of the shock-cell structure. In
particular, interactions between the vortex ring and the Mach disk connected with a
strong second shock affect remarkably the formation process of the first shock cell.
Different formation processes of the first cell structure are found. It is also made clear
that the Kelvin–Helmholtz instability along slip surfaces originating from the triple
point at the outer edge of the Mach disk is responsible for the generation of large
second vortices which entrain the first vortex. This results in strong mixing between
the primary jet and surrounding gas for higher pressure ratios. Numerical simulations
with a TVD-scheme for the Euler equations are also performed and the numerical
results are compared with the experimental ones to understand and predict the flow
characteristics of the pulse jets.
The vacuum level shift A was determined by Kelvin probe method for TPD/metal systems prepared in ultrahigh vacuum (TPD: N, N'-bis(3-methylphenyl)-N, N'-diphenyl-[1, 1'-biphenyl]-4,4'-diamine). The energy of the vacuum level sharply changed at the initial stage of depositing TPD on the metal substrates, and further bending was not observed up to 100 nm thickness of TPD. This result is consistent with our previous studies of ultraviolet photoelectron spectroscopy. These results indicate the invalidity of traditional model with a common vacuum level at organic/metal interface. We discussed the dependence of the vacuum level shift on the work function Φm of the metal substrate (Au, Cu, Ag, Mg, and Ca). A liner correlation between Δ and Φm was observed only in the region of 3.8 eV < Φm < 4.5 eV, indicating that Fermi level alignment is not achieved at least for some interfaces. We found that Δ for TPD film on the air-exposed metal substrate is smaller than that of TPD on clean metals and was observed a liner relation between Φm and Δ except for the Cu substrate.
Metal deposition on a p-sexiphenyl (6P) film was studied by ultraviolet photoelectron spectroscopy (UPS), metastable atom electron spectroscopy (MAES), and X-ray photoelectron spectroscopy (XPS). The deposited metals were Au, Mg, and several alkali metals (K, Na, Rb, and Cs). No chemical reaction between 6P and Au or Mg was observed in the measured spectra, while additional gap states appeared in the UPS and MAES spectra by deposition of the alkali metals. The diffusion of Au and Mg atoms into the 6P film was observed in the MAES spectra. We found the trend of the vacuum level shift is different between the systems of the 6P on the Au and its reversed systems (Au on the 6P film), suggesting the different formation of the interface depending on the deposition sequence.
This paper presents the current advances in the development of materials in the field of telecommunication wiring together with the background which created the need for the new technologies. The background is somewhat unique to the current socio-economical situation of Japan. The key technical areas, which are addressed in this paper, are; (1) fibers for transmission of over 1 Tbps by utilizing WDM (wavelength division multiplexing), (2) fibers for fiber amplifiers to replace repeaters within trunk lines, (3) high density cables with over 1000 fiber counts, (4) ABF (air blown fiber) for access system, (5) plastic optical fibers wiring in premises or offices operating at the transmission speed of over 200 Mbps.