72 research outputs found
Delta degrees of freedom in antisymmetrized molecular dynamics and (p,p') reactions in the delta region
Delta degrees of freedom are introduced into antisymmetrized molecular
dynamics (AMD). This is done by increasing the number of basic states in the
AMD wave function, introducing a Skyrme-type delta-nucleon potential, and
including reactions in the collision description.
As a test of the delta dynamics, the extended AMD is applied to (p,p)
recations at MeV for a C target. It is found that the
ratio and the absolute values for delta peak and quasielastic peak (QEP) in the
C(p,p) reaction are reproduced for angles \Theta_{\rm lab} \agt
40^\circ, pointing to a correct treatment of the delta dynamics in the
extended AMD. For forward angles the QEP is overestimated. The results of the
AMD calculations are compared to one-step Monte Carlo (OSMC) calculations and a
detailed analysis of multi-step and delta potential effects is given. As
important side results we present a way to apply a Gallilei invariant theory
for (N,N) reactions up to MeV which ensures
approximate Lorentz invariance and we discuss how to fix the width parameter
of the single particle momentum distribution for outgoing nucleons in the
AMD calculation.Comment: 28 pages, revtex, 12 figures included, figures are also available
upon request as postscript files from the authors (e-mail:
[email protected]), submitted to Phys. Rev.
Evidence for a companion to BM Gem, a silicate carbon star
Balmer and Paschen continuum emission as well as Balmer series lines of P
Cygni-type profile from H_gamma through H_23 are revealed in the violet spectra
of BM Gem, a carbon star associated with an oxygen-rich circumstellar shell
(`silicate carbon star') observed with the high dispersion spectrograph (HDS)
on the Subaru telescope. The blue-shifted absorption in the Balmer lines
indicates the presence of an outflow, the line of sight velocity of which is at
least 400 km s^-1, which is the highest outflow velocity observed to date in a
carbon star. We argue that the observed unusual features in BM Gem are strong
evidence for the presence of a companion, which should form an accretion disk
that gives rise to both an ionized gas region and a high velocity, variable
outflow. The estimated luminosity of ~0.2 (0.03-0.6) L_sun for the ionized gas
can be maintained by a mass accretion rate to a dwarf companion of ~10^-8 M_sun
yr^-1, while ~10^-10 M_sun yr^-1 is sufficient for accretion to a white dwarf
companion. These accretion rates are feasible for some detached binary
configurations on the basis of the Bond-Hoyle type accretion process. We
concluded that the carbon star BM Gem is in a detached binary system with a
companion of low mass and low luminosity. However, we are unable to determine
whether this companion object is a dwarf or a white dwarf. The upper limits for
binary separation are 210 AU and 930 AU for a dwarf and a white dwarf,
respectively. We also note that the observed features of BM Gem mimic those of
Mira (omi Cet), which may suggest actual similarities in their binary
configurations and circumstellar structures.Comment: 11 pages, 2 figures, 1 table, accepted for publication in Ap
Proton inelastic scattering to continuum studied with antisymmetrized molecular dynamics
Intermediate energy (p,px) reaction is studied with antisymmetrized
molecular dynamics (AMD) in the cases of Ni target with MeV
and C target with 200 and 90 MeV. Angular distributions for
various energies are shown to be reproduced well without any
adjustable parameter, which shows the reliability and usefulness of AMD in
describing light-ion reactions. Detailed analyses of the calculations are made
in the case of Ni target and following results are obtained: Two-step
contributions are found to be dominant in some large angle region and to be
indispensable for the reproduction of data. Furthermore the reproduction of
data in the large angle region \theta \agt 120^\circ for = 100 MeV
is shown to be due to three-step contributions. Angular distributions for
E_{p'} \agt 40 MeV are found to be insensitive to the choice of different
in-medium nucleon-nucleon cross sections and the reason of this
insensitivity is discussed in detail. On the other hand, the total reaction
cross section and the cross section of evaporated protons are found to be
sensitive to . In the course of the analyses of the calculations,
comparison is made with the distorted wave approach.Comment: 16 pages, 7 Postscript figure
The Erotic and the Vulgar: Visual Culture and Organized Labor's Critique of U.S. Hegemony in Occupied Japan
This essay engages the colonial legacy of postwar Japan by arguing that the political cartoons produced as part of the postwar Japanese labor movement’s critique of U.S. cultural hegemony illustrate how gendered discourses underpinned,
and sometimes undermined, the ideologies formally represented by visual artists and the organizations that funded them. A significant component of organized
labor’s propaganda rested on a corpus of visual media that depicted women as icons of Japanese national culture. Japan’s most militant labor unions were propagating anti-imperialist discourses that invoked an engendered/endangered nation that accentuated the importance of union roles for men by subordinating, then eliminating, union roles for women
Genome-Wide Haplotype Changes Produced by Artificial Selection during Modern Rice Breeding in Japan
During the last 90 years, the breeding of rice has delivered cultivars with improved agronomic and economic characteristics. Crossing of different lines and successive artificial selection of progeny based on their phenotypes have changed the chromosomal constitution of the ancestors of modern rice; however, the nature of these changes is unclear. The recent accumulation of data for genome-wide single-nucleotide polymorphisms (SNPs) in rice has allowed us to investigate the change in haplotype structure and composition. To assess the impact of these changes during modern breeding, we studied 177 Japanese rice accessions, which were categorized into three groups: landraces, improved cultivars developed from 1931 to 1974 (the early breeding phase), and improved cultivars developed from 1975 to 2005 (the late breeding phase). Phylogenetic tree and structure analysis indicated genetic differentiation between non-irrigated (upland) and irrigated (lowland) rice groups as well as genetic structuring within the irrigated rice group that corresponded to the existence of three subgroups. Pedigree analysis revealed that a limited number of landraces and cultivars was used for breeding at the beginning of the period of systematic breeding and that 11 landraces accounted for 70% of the ancestors of the modern improved cultivars. The values for linkage disequilibrium estimated from SNP alleles and the haplotype diversity determined from consecutive alleles in five-SNP windows indicated that haplotype blocks became less diverse over time as a result of the breeding process. A decrease in haplotype diversity, caused by a reduced number of polymorphisms in the haplotype blocks, was observed in several chromosomal regions. However, our results also indicate that new haplotype polymorphisms have been generated across the genome during the breeding process. These findings will facilitate our understanding of the association between particular haplotypes and desirable phenotypes in modern Japanese rice cultivars
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Plant-symbiotic fungi as chemical engineers: multi-genome analysis of the Clavicipitaceae reveals dynamics of alkaloid Loci
The fungal family Clavicipitaceae includes plant symbionts and parasites that produce several psychoactive and bioprotective alkaloids. The family includes grass symbionts in the epichloae clade (Epichloë and Neotyphodium species), which are extraordinarily diverse both in their host interactions and in their alkaloid profiles. Epichloae produce alkaloids of four distinct classes, all of which deter insects, and some—including the infamous ergot alkaloids—have potent effects on mammals. The exceptional chemotypic diversity of the epichloae may relate to their broad range of host interactions, whereby some are pathogenic and contagious, others are mutualistic and vertically transmitted (seed-borne), and still others vary in pathogenic or mutualistic behavior. We profiled the alkaloids and sequenced the genomes of 10 epichloae, three ergot fungi (Claviceps species), a morning-glory symbiont (Periglandula ipomoeae), and a bamboo pathogen (Aciculosporium take), and compared the gene clusters for four classes of alkaloids. Results indicated a strong tendency for alkaloid loci to have conserved cores that specify the skeleton structures and peripheral genes that determine chemical variations that are known to affect their pharmacological specificities. Generally, gene locations in cluster peripheries positioned them near to transposon-derived, AT-rich repeat blocks, which were probably involved in gene losses, duplications, and neofunctionalizations. The alkaloid loci in the epichloae had unusual structures riddled with large, complex, and dynamic repeat blocks. This feature was not reflective of overall differences in repeat contents in the genomes, nor was it characteristic of most other specialized metabolism loci. The organization and dynamics of alkaloid loci and abundant repeat blocks in the epichloae suggested that these fungi are under selection for alkaloid diversification. We suggest that such selection is related to the variable life histories of the epichloae, their protective roles as symbionts, and their associations with the highly speciose and ecologically diverse cool-season grasses
Changes in Cerebral Hemodynamics during Complex Motor Learning by Character Entry into Touch-Screen Terminals
Introduction Studies of cerebral hemodynamics during motor learning have mostly focused on neurorehabilitation interventions and their effectiveness. However, only a few imaging studies of motor learning and the underlying complex cognitive processes have been performed. Methods We measured cerebral hemodynamics using near-infrared spectroscopy (NIRS) in relation to acquisition patterns of motor skills in healthy subjects using character entry into a touchscreen terminal. Twenty healthy, right-handed subjects who had no previous experience with character entry using a touch-screen terminal participated in this study. They were asked to enter the characters of a randomly formed Japanese syllabary into the touchscreen terminal. All subjects performed the task with their right thumb for 15 s alternating with 25 s of rest for 30 repetitions. Performance was calculated by subtracting the number of incorrect answers from the number of correct answers, and gains in motor skills were evaluated according to the changes in performance across cycles. Behavioral and oxygenated hemoglobin concentration changes across task cycles were analyzed using Spearman\u27s rank correlations. Results Performance correlated positively with task cycle, thus confirming motor learning. Hemodynamic activation over the left sensorimotor cortex (SMC) showed a positive correlation with task cycle, whereas activations over the right prefrontal cortex (PFC) and supplementary motor area (SMA) showed negative correlations. Conclusions We suggest that increases in finger momentum with motor learning are reflected in the activity of the left SMC. We further speculate that the right PFC and SMA were activated during the early phases of motor learning, and that this activity was attenuated with learning progress
A preliminary study of individual cognitive behavior therapy for social anxiety disorder in Japanese clinical settings: a single-arm, uncontrolled trial
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