819 research outputs found
Proton and neutron correlations in B
We investigate positive-parity states of B with the calculation of
antisymmetrized molecular dynamics focusing on pair correlations. We
discuss effects of the spin-orbit interaction on energy spectra and
correlations of the , , and states. The
state has almost no energy gain of the spin-orbit interaction, whereas
the state gains the spin-orbit interaction energy largely to come down
to the ground state. We interpret a part of the two-body spin-orbit interaction
in the adopted effective interactions as a contribution of the genuine
force, and find it to be essential for the level ordering of the and
states in B. We also apply a model to discuss
effects of the spin-orbit interaction on and pairs around the
2 core. In the spin-aligned state, the spin-orbit
interaction affects the pair attractively and keeps the pair close
to the core, whereas, in the state, it gives a minor effect to the
pair. In the state, the pair is somewhat
dissociated by the spin-orbit interaction.Comment: 12 pages 9 figure
Breaking of N=8 magicity in 13Be
Structure of Be was investigated with antisymmetrized molecular
dynamics. The variation after spin and parity projections was performed. An
unnatural parity state was suggested to be lower than state
indicating that vanishing of the N=8 magic number occurs in Be. A
low-lying state with a configuration was also suggested.
Developed cluster structures were found in the intruder states. Lowering
mechanism of the intruder states was discussed in terms of molecular orbitals
around a core.Comment: 9 pages, 8 figures, submitted to PR
Construction of a topological charge on fuzzy S^2 x S^2 via Ginsparg-Wilson relation
We construct a topological charge of gauge field configurations on a fuzzy
S^2xS^2 by using a Dirac operator satisfying the Ginsparg-Wilson relation. The
topological charge defined on the fuzzy S^2xS^2 can be interpreted as a
noncommutative (or matrix) generalization of the 2nd Chern character on
S^2xS^2. We further calculate the number of chiral zero modes of the Dirac
operator in topologically nontrivial gauge configurations. Generalizations of
our formulation to fuzzy (S^2)^k are also discussed.Comment: 30 pages, typo corrected, version published in Phys.Rev.
Anticardiolipin Antibodies Recognize β(2)-Glycoprotein I Structure Altered by Interacting with an Oxygen Modified Solid Phase Surface
Anticardiolipin antibodies (aCL) derived from the sera of individuals exhibiting the antiphospholipid syndrome (APS) directly bind to beta(2)-glycoprotein I (beta(2)-GPI), which is adsorbed to an oxidized polystyrene surface. Oxygen atoms were introduced on a polystyrene surface by irradiation with electron or gamma-ray radiation. X-ray photoelectron spectroscopy revealed the irradiated surfaces were oxidized to generate C-O and C=O moieties. aCL derived from either APS patients or (NZW x BXSB)F-1 mice bound to beta(2)-GPI coated on the irradiated plates, depending on the radiation dose. Antibody binding to beta(2)-GPI on the irradiated plates was competitively inhibited by simultaneous addition of cardiolipin (CL)-coated latex beads mixed together with beta(2)-GPI but were unaffected by addition of excess beta(2)-GPI, CL micelles, or CL-coated latex beads alone. There was a high correlation between binding values of aCL in sera from 40 APS patients obtained by the anti-beta(2)-GPI enzyme-linked immunosorbent assay (ELISA) using the irradiated plates and those by the beta(2)-GPI-dependent aCL ELISA. Therefore, aCL have specificity for an epitope on beta(2)-GPI. This epitope is expressed by a conformational change occurring when beta(2)-GPI interacts with an oxygen-substituted solid phase surface
A new N* resonance as a hadronic molecular state
We report our recent work on a hadronic molecule state of the KbarKN system
with I=1/2 and J^P=1/2^+. We assume that the Lambda(1405) resonance and the
scalar mesons, f_{0}(980), a_{0}(980), are reproduced as quasi-bound states of
KbarN and KbarK, respectively. Performing non-relativistic three-body
calculations with a variational method for this system, we find a quasibound
state of the KbarKN system around 1910 MeV below the three-body breakup
threshold. This state corresponds to a new baryon resonance of N* with
J^P=1/2^+. We find also that this resonance has the cluster structure of the
two-body bound states keeping their properties as in the isolated two-particle
systems. We also briefly discuss another hadronic molecular state composed by
two Kbar and one N, which corresponds to a Xi^* resonance.Comment: Talk given at Workshop on the Physics of Excited Nucleon --
NSTAR2009, Beijing April 19 - 22, 200
Triaxial quadrupole deformation dynamics in sd-shell nuclei around 26Mg
Large-amplitude dynamics of axial and triaxial quadrupole deformation in
24,26Mg, 24Ne, and 28Si is investigated on the basis of the quadrupole
collective Hamiltonian constructed with use of the constrained
Hartree-Fock-Bogoliubov plus the local quasiparticle random phase approximation
method. The calculation reproduces well properties of the ground rotational
bands, and beta and gamma vibrations in 24Mg and 28Si. The gamma-softness in
the collective states of 26Mg and 24Ne are discussed. Contributions of the
neutrons and protons to the transition properties are also analyzed in
connection with the large-amplitude quadrupole dynamics.Comment: 16 pages, 18 figures, submitted to Phys. Rev.
Index theorem in spontaneously symmetry-broken gauge theories on a fuzzy 2-sphere
We consider a gauge-Higgs system on a fuzzy 2-sphere and study the
topological structure of gauge configurations, when the U(2) gauge symmetry is
spontaneously broken to U(1) times U(1) by the vev of the Higgs field. The
topology is classified by the index of the Dirac operator satisfying the
Ginsparg-Wilson relation, which turns out to be a noncommutative analog of the
topological charge introduced by 't Hooft. It can be rewritten as a form whose
commutative limit becomes the winding number of the Higgs field. We also study
conditions which assure the validity of the formulation, and give a
generalization of the admissibility condition. Finally we explicitly calculate
the topological charge of a one-parameter family of configurations.Comment: 37 pages, 3 figures, typo corrected, version published in Physical
Review
The Diffusion of the Magnetization Profile in the XX-model
By the -algebraic method, we investigate the magnetization profile in
the intermediate time of diffusion. We observe a transition from monotone
profile to non-monotone profile. This transition is purely thermal.Comment: Accepted for publication in Phys. Rev.
Cilostazol Attenuates AngII-Induced Cardiac Fibrosis in apoE Deficient Mice
Cardiac fibrosis is characterized by the net accumulation of extracellular matrix in the myocardium and is an integral component of most pathological cardiac conditions. Cilostazol, a selective inhibitor of phosphodiesterase type III with anti-platelet, anti-mitogenic, and vasodilating properties, is widely used to treat the ischemic symptoms of peripheral vascular disease. Here, we investigated whether cilostazol has a protective effect against Angiotensin II (AngII)-induced cardiac fibrosis. Male apolipoprotein E-deficient mice were fed either a normal diet or a diet containing cilostazol (0.1% wt/wt). After 1 week of diet consumption, the mice were infused with saline or AngII (1000 ng kg(-1) min(-1)) for 28 days. AngII infusion increased heart/body weight ratio (p < 0.05), perivascular fibrosis (p < 0.05), and interstitial cardiac fibrosis (p < 0.0001), but were significantly attenuated by cilostazol treatment (p < 0.05, respectively). Cilostazol also reduced AngII-induced increases in fibrotic and inflammatory gene expression (p < 0.05, respectively). Furthermore, cilostazol attenuated both protein and mRNA abundance of osteopontin induced by AngII in vivo. In cultured human cardiac myocytes, cilostazol reduced mRNA expression of AngII-induced osteopontin in dose-dependent manner. This reduction was mimicked by forskolin treatment but was cancelled by co-treatment of H-89. Cilostazol attenuates AngII-induced cardiac fibrosis in mice through activation of the cAMP-PKA pathway
Pupil size is modulated by the size of equal-luminance gratings
© 2020 The Authors. Pupil size changes with light. For this reason, researchers studying the effect of attention, contextual processing, and arousal on the pupillary response have matched the mean luminance of their stimuli across conditions to eliminate the contribution of differences in light levels. Here, we argue that the match of mean luminance is not enough. In Experiment 1, we presented a circular sinewave grating on a gray background for 2 seconds. The area of the grating could be 3°, 6°, or 9°. The mean luminance of each grating was equal to the luminance of the gray background, such that regardless of the size of the grating there was no change in mean luminance between conditions. Participants were asked to fixate the center of the grating and passively view it. We found that in all size conditions, there was a pupil constriction starting at about 300 ms after stimulus onset, and the pupil constriction increased with the size of the grating. In Experiment 2, when a small grating was presented immediately after the presentation of a large grating (or vice versa), the pupil constriction changed accordingly. In Experiment 3, we replicated Experiment 1 but had the subjects perform an attention-demanding fixation task in one session, and passively view the stimuli in the other. We found that the main effect of task was not significant. In sum, our results show that stimulus size can modulate pupil size robustly and steadily even when the luminance is matched across the different stimuli
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