Universal dark halo scaling relation for the dwarf spheroidal satellites

Motivated by a recently found interesting property of the dark halo surface density within a radius, $r_{\rm max}$, giving the maximum circular velocity, $V_{\rm max}$, we investigate it for dark halos of the Milky Way's and Andromeda's dwarf satellites based on cosmological simulations. We select and analyze the simulated subhalos associated with Milky Way-sized dark halos and find that the values of their surface densities, $\Sigma_{V_{\rm max}}$, are in good agreement with those for the observed dwarf spheroidal satellites even without employing any fitting procedures. This implies that this surface density would not be largely affected by any baryonic feedbacks and thus universal. Moreover, all subhalos on the small scales of dwarf satellites are expected to obey the relation $\Sigma_{V_{\rm max}}\propto V_{\rm max}$, irrespective of differences in their orbital evolutions, host halo properties, and observed redshifts. Therefore, we find that the universal scaling relation for dark halos on dwarf galaxy mass scales surely exists and provides us important clues to understanding fundamental properties of dark halos. We also investigate orbital and dynamical evolutions of subhalos to understand the origin of this universal dark halo relation and find that most of subhalos evolve generally along the $r_{\rm max}\propto V_{\rm max}$ sequence, even though these subhalos have undergone different histories of mass assembly and tidal stripping. This sequence, therefore, should be the key feature to understand the nature of the universality of $\Sigma_{V_{\rm max}}$.Comment: 12 pages, 5 figures and 3 tables, submitted to Ap

EXFOR-based simultaneous evaluation for neutron-induced fission cross section of plutonium-242

The $^{242}$Pu neutron-induced fission cross section was evaluated from 100 keV to 200 MeV. The experimental $^{242}$Pu and $^{235}$U fission cross sections and their ratios in the EXFOR library were reviewed and analysed by the least-squares method. Additional simultaneous evaluation was performed by including the experimental database of the $^{233,238}$U and $^{239,240,241}$Pu fission cross sections and their ratios developed for JENDL-5 evaluation. The $^{242}$Pu fission cross sections from our evaluation and JENDL-5 evaluation are close to each other below 1 MeV while systematically differ from each other above 10 MeV. The cross section from our evaluation is systematically lower than the JENDL-4.0 cross section in the prompt fission neutron spectrum peak region ($\sim$5% lower around 1 MeV). The newly evaluated $^{242}$Pu fission cross section was verified against the cross section measured in the $^{252}$Cf spontaneous fission neutron field and criticalities of small-sized LANL fast systems, and demonstrated better performance than the JENDL-4.0 cross section on the same level with the JENDL-5 cross section.Comment: Submitted to Journal of Nuclear Science and Technolog

Benchmarks of subcriticality in accelerator-driven system at Kyoto University Critical Assembly

Basic research on the accelerator-driven system is conducted by combining U-235-fueled and Th-232-loaded cores in the Kyoto University Critical Assembly with the pulsed neutron generator (14 MeV neutrons) and the proton beam accelerator (100 MeV protons with a heavy metal target). The results of experimental subcriticality are presented with a wide range of subcriticality level between near critical and 10,000 pcm, as obtained by the pulsed neutron source method, the Feynman-alpha method, and the neutron source multiplication method

Neutron Generation Time in Highly-Enriched Uranium Core at Kyoto University Critical Assembly

At the Kyoto University Critical Assembly experiments on kinetics parameters are carried out at near-critical configurations, supercritical and subcritical states, in the thermal neutron spectrum made with a highly enriched uranium fuel. The main calculated kinetics parameters, the effective delayed neutron fraction (βeff) and the neutron generation time (Ʌ), are used effectively for the estimation of experimental parameters, and the accuracy of experiments on prompt neutron decay constant (α) and subcriticality (ρ$) in dollar units is attained by the numerical results of βeff and Ʌ. Furthermore, the value of βeff/Ʌ is experimentally deduced with the use of the experimental results of α and ρ$, ranging between 250 and −80 pcm. Thus, the experimentally deduced values of βeff/Ʌ that reveal good accuracy through a comparison with those by the MCNP6.1 calculations with JENDL-4.0 are then taken as an index of Ʌ by introducing an acceptable assumption of βeff at near-critical configurations. From the results of experimental and numerical analyses, the experimental value of βeff/Ʌ is important for the validation of Ʌ since kinetics parameters are successfully obtained from the clean cores of near-critical configurations in the thermal neutron spectrum

Structural evolution in the neutron-rich nuclei 106Zr and 108Zr

The low-lying states in 106Zr and 108Zr have been investigated by means of {\beta}-{\gamma} and isomer spectroscopy at the RI beam factory, respectively. A new isomer with a half-life of 620\pm150 ns has been identified in 108Zr. For the sequence of even-even Zr isotopes, the excitation energies of the first 2+ states reach a minimum at N = 64 and gradually increase as the neutron number increases up to N = 68, suggesting a deformed sub-shell closure at N = 64. The deformed ground state of 108Zr indicates that a spherical sub-shell gap predicted at N = 70 is not large enough to change the ground state of 108Zr to the spherical shape. The possibility of a tetrahedral shape isomer in 108Zr is also discussed.Comment: 10 pages, 3 figures, Accepted for publication in Phys. Rev. Let

<原著論文>南半球強豪3 カ国のブレイクダウンにおける防御プレーの分析 : ニュージーランドの特徴に着目して

The purpose of this study was to clarify defense play in breakdown in world top-level rugby and features of New Zealand by comparing the three countries. In order to fulfill this purpose we analyzed 12 matches of The Rugby Championship in 2016 and 2017. In these games, New Zealand, Australia and South Africa played against each other. Subjects of this study were 1772 of rucks with continued to possess the ball. We analyzed the number of defensive players involved in breakdown and “ball out ruck”, the time required to get the ball-out from rucks, and the actions of the tacklers and arriving players. Also we used Fisher’s exact test to verify significant difference in the ratios. The significance level was set at 5％ (two -sided test). The main results are as follows: 1) At the world top-level rugby, the following results were obtained. The number of player of “ball out ruck” was decreasing, 15％ was nobody, 53％ was one. 38％ was one tackler and 53％ were two. 63％ was nobody of arriving players. 2) In New Zealand, the ratio of the small number of “ball out ruck” was high. Also, the “reload” rate was high, especially “reload” rate at “non-contest” was high. And “reload” rate was high with “ball-out time” less than 2.5 seconds

Capability and Limitations of Recent Diagnostic Criteria for Autoimmune Pancreatitis

Because a diagnostic serological marker is unavailable, autoimmune pancreatitis (AIP) is diagnosed based on unique features. The diagnostic capabilities and potential limitations of four sets of diagnostic criteria for AIP (Japanese diagnostic criteria 2006 and 2011, Asian diagnostic criteria, and international consensus diagnostic criteria (ICDC)) were compared among 85 patients who were diagnosed AIP according to at least one of the four sets. AIP was diagnosed in 87%, 95%, 95%, and 95% of the patients according to the Japanese 2006, Asian, ICDC, and Japanese 2011 criteria, respectively. The ICDC can diagnose types 1 and 2 AIP independently and show high sensitivity for diagnosis of AIP. However, as the ICDC are rather complex, diagnostic criteria for AIP should perhaps be revised and tailored to each country based on the ICDC

Uninvestigated dyspepsia and non-ulcer dyspepsia—the use of endoscopy and the roles of Helicobacter pylori eradication and antisecretory therapy

Due to its prevalence, impact on quality-of-life and the associated significant health resource utilization, dyspepsia is a major healthcare concern. The available management strategies for uninvestigated dyspepsia include prompt endoscopy, the ‘test-and-treat’ strategy for Helicobacter pylori , and empiric antisecretory therapy. There is consensus that endoscopy should be reserved for patients with alarm features (e.g. symptom onset after 45 years of age, recurrent vomiting, weight loss, dysphagia, evidence of bleeding, anaemia), H. pylori -positive individuals who fail test-and-treat, and those with an inadequate response to empiric antisecretory therapy. Factors influencing the decision between test-and-treat and empiric antisecretory therapy in uninvestigated dyspepsia include the local prevalence of H. pylori and peptic ulcer disease and the proportion of ulcers attributable to H. pylori . For uninvestigated dyspepsia in patients without alarm features, test-and-treat is the preferred initial management method in Europe based on the relatively high prevalence of H. pylori /peptic ulcer disease whereas empiric antisecretory therapy is preferred in many parts of the United States, where the prevalence of H. pylori /peptic ulcer disease is relatively low. In patients with non-ulcer dyspepsia, H. pylori eradication and empiric antisecretory therapy result in comparable and small, but statistically significant, improvements in dyspepsia. Empiric antisecretory therapy is the preferred initial method of managing non-ulcer dyspepsia in Europe and the US. The test-and-treat approach would receive increased enthusiasm if H. pylori cure is shown to prevent development of gastric cancer in non-ulcer dyspepsia patients in a large Western trial.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72556/1/j.0953-0673.2004.01829.x.pd