We compare three different statistical models for the equation of state (EOS) of stellar matter at subnuclear densities and temperatures (0.5–10 MeV) expected to occur during the collapse of massive ...stars and supernova explosions. The models introduce the distributions of various nuclear species in nuclear statistical equilibrium, but use somewhat different nuclear physics inputs. It is demonstrated that the basic thermodynamical quantities of stellar matter under these conditions are similar, except in the region of high densities and low temperatures. We demonstrate that mass and isotopic distributions have considerable differences related to the different assumptions of the models on properties of nuclei at these stellar conditions. Overall, the three models give similar trends, but the details reflect the uncertainties related to the modeling of medium effects, such as the temperature and density dependence of surface and bulk energies of heavy nuclei, and the nuclear shell structure effects. We discuss importance of new physics inputs for astrophysical calculations from experimental data obtained in intermediate energy heavy-ion collisions, in particular, the similarities of the conditions reached during supernova explosions and multifragmentation reactions.
Herein, we review the nuclear equations of state (EOSs) and the constituent nuclei of core-collapse supernovae (CCSNe) and their roles in CCSN simulations. Various nuclei such as deuterons, iron, and ...extremely neutron-rich nuclei compose in the central engines of CCSNe. The center of a collapsing core is dominated by neutron-rich heavy nuclei prior to the occurrence of core bounce. Their weak interactions significantly affect the neutrino emission and the size of the produced proto-neutron star. After a core bounce, heavy nuclei are dissolved to protons, neutrons, and light nuclei between the expanding shock wave and the newly formed neutron star (NS). Some of the key components in determining the shock-wave dynamics and supernova explosion of outer envelopes are neutrino interactions of nucleons and light nuclei such as deuterons. An EOS provides the relations between thermodynamical properties and the nuclear composition, and is needed to simulate this explosion. Further investigations on uniform and non-uniform nuclear matter are needed to improve the understanding of the mechanism of CCSNe and the properties of supernova nuclei. The knowledge of the EOS for uniform nuclear matter is being continually improved by a combination of microscopic calculations, terrestrial experiments, and NS observations. With reference to various nuclear experiments and current theories, the finite temperature effects on heavy nuclei, formation of light nuclei in dilute nuclear matter, and transition to uniform nuclear matter should be improved in the model of the EOS for non-uniform nuclear matter.
We perform numerical experiments to investigate the influence of inelastic neutrino reactions with light nuclei on the standing accretion shock instability. The time evolutions of shock waves are ...calculated with a simple light-bulb approximation for the neutrino transport and a multi-nuclei equation of state. The neutrino absorptions and inelastic interactions with deuterons, tritons, helions and alpha particles are taken into account in the hydrodynamical simulations in addition to the ordinary charged-current interactions with nucleons. Axial symmetry is assumed but no equatorial symmetry is imposed. We show that the heating rates of deuterons reach as high as ∼ 10% of those of nucleons around the bottom of the gain region. On the other hands, alpha particles heat the matter near the shock wave, which is important when the shock wave expands and density and temperature of matter become low. It is also found that the models with heating by light nuclei have different evolutions from those without it in non-linear evolution phase. The matter in the gain region has various densities and temperatures and there appear regions that are locally rich in deuterons and alpha particles. These results indicate that the inelastic reactions of light nuclei, especially deuterons, should be incorporated in the simulations of core-collapse supernovae.
Amorphous lithium lanthanum titanate (LLT) thin films were prepared by the pulsed laser deposition (PLD) method. By X-ray diffraction measurement of the films, it was confirmed that the crystal ...structure of the as-prepared thin films was amorphous. The temperature dependence of the ionic conductivity of the amorphous LLT thin film was measured from 300 to 475 K over the frequency region 100 Hz to 10 MHz. The value 0.35 eV was estimated as the activation energy of Li
+ ionic conduction in the film in the temperature region 300–475 K. It was revealed that the transfer ratio of Li
+ ion for the ionic conduction of the amorphous LLT thin film is over 94%, and the amorphous LLT thin film shows super-ionic conduction at and above room temperature. The conductivity of the LLT thin film was an order of magnitude higher than that of its polycrystalline precursor, mainly due to absence of grain boundary elements and its structural disorder.
We examined intraspecies genetic variation in house mice (Mus musculus molossinus) from the northern third of the Japanese Islands, in order to obtain evidence of the history of mouse colonization ...that might have shaped the current genetic diversity. We extended the previous sampling of mitochondrial cytochrome b sequence and added information from the Y-linked Sry gene and ribosomal RNA gene surveys. We distinguish mitochondrial haplotypes characteristic of the North Asian musculus subspecies group (involving M. m. musculus and M. m. molossinus) as 'MUS', and that of the Southeast Asian castaneus subspecies group as 'CAS' (although the mice resemble MUS morphologically). There was a clear geographic partition of MUS and CAS types into southern and northern Hokkaido, respectively. Conversely, on Tohoku, the MUS and CAS types were interspersed without clear geographic subdivision. In contrast to the mtDNA data, all Hokkaido and Tohoku mice examined were found to possess a unique type for the Y-linked Sry gene, specific to Korea and Japan. Restriction site analysis of nuclear rDNA probe showed a consistent distribution of MUS and CAS types, as major and minor components, respectively, in the Hokkaido and Tohoku mice. These data support the previous notion that the Hokkaido and Tohoku mice experienced genetic hybridization between primary residents of CAS origin and MUS newcomers arriving via a southern route. The invasion of the MUS type could correspond with the evidence for arrival of prehistoric peoples. There are, however, alternative interpretations, including genetic admixture between MUS arriving by a southern route and CAS from a northern route.
It has been believed that the peripheral lymphocytes in chickens proliferate by self‐renewing amplification of the preimmune repertoire generated in bursa. We amplified rearranged immunoglobulin ...variable (V) region genes from the single germinal centers induced by immunization. The sequence analysis of these genes revealed that most were derived from distinct B‐cell clones which expanded locally, generating somatic antibody mutants at a high rate. Somatic hypermutations included unlinked base changes and the linked base modifications interpreted as unidirectional transfer of sequences from V region pseudogenes. This finding demonstrates the ongoing post‐bursal diversification of B‐cells in splenic germinal centers by templated gene conversion as well as untemplated point mutations.
SUMMARY
The superoxide (O2‐releasing capacity in response lo N‐fomiyl‐methionyl‐leucyl‐phenylalanine (FMLP)and the priming effects ofrecombinant human granuloeyte colony‐stimulating factor (rhG‐CSF) ...and granulocyte‐macrophage colony‐stimulating faclor (rhGM‐CSF) on FMLP‐induced O2 release were investigated in neutrophils from 14 patients with myelodysplastic syndromes (MDS). The O2 ‐releasing capacity in MDS neutrophils varied from patient to patient. As compared with normal neutJ‐ophils. theO2‐releasing capacity in MDS neutrophils was increased in 9/14 patients, nonnal in three patients and decreased in two patients. There was no close relationship between the 02‐reIeasing capacity and the peripheral blood neutrophil count or the plasma concentration of C‐reactive protein. The priming of neutrophils by rhG‐CSF was not observed in five patients, whereas rhGM‐CSF primed neutrophils from all patients. The priming eflect of rhGM‐CSF was consistently greater than that of rhG‐CSF in each patient. The intravenous administration of rhG‐CSF (300 μg/body) to two MDS patients showed an increase in the peripheral blood neutrophil count and enhancement of neutrophil O2 release. These findings demonstrate that the neutrophil O2‐releasing capacity in MDS varies from patient to patient and is not always impaired, and that rhGM‐CSF is able to prime neutrophils which never respond to rhG‐CSF.
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