Constraint on Heavy Element Production in Inhomogeneous Big-Bang Nucleosynthesis from The Light-Element Observations

We investigate the observational constraints on the inhomogeneous big-bang nucleosynthesis that Matsuura et al. suggested the possibility of the heavy element production beyond ${}^7$Li in the early universe. From the observational constraints on light elements of ${}^4$He and D, possible regions are found on the plane of the volume fraction of the high density region against the ratio between high-and low-density regions. In these allowed regions, we have confirmed that the heavy elements beyond Ni can be produced appreciably, where $p$- and/or $r$-process elements are produced well simultaneously.Comment: 11 pages, 7 figures, 4 Tables., accepted in Journal of Astrophysics. arXiv admin note: substantial text overlap with arXiv:1007.046

Numerical experiments of adjusted BSSN systems for controlling constraint violations

We present our numerical comparisons between the BSSN formulation widely used in numerical relativity today and its adjusted versions using constraints. We performed three testbeds: gauge-wave, linear wave, and Gowdy-wave tests, proposed by the Mexico workshop on the formulation problem of the Einstein equations. We tried three kinds of adjustments, which were previously proposed from the analysis of the constraint propagation equations, and investigated how they improve the accuracy and stability of evolutions. We observed that the signature of the proposed Lagrange multipliers are always right and the adjustments improve the convergence and stability of the simulations. When the original BSSN system already shows satisfactory good evolutions (e.g., linear wave test), the adjusted versions also coincide with those evolutions; while in some cases (e.g., gauge-wave or Gowdy-wave tests) the simulations using the adjusted systems last 10 times as long as those using the original BSSN equations. Our demonstrations imply a potential to construct a robust evolution system against constraint violations even in highly dynamical situations.Comment: to be published in PR

Hypernova Nucleosynthesis and Implications for Cosmic Chemical Evolution

We examine the characteristics of nucleosynthesis in 'hypernovae', i.e., supernovae with very large explosion energies (\gsim 10^{52} ergs). Implications for the cosmic chemical evolution and the abundances in M82 are discussed.Comment: To appear in 'Cosmic Evolution' Conference at IAP, Paris, honoring Jean Audouze and Jim Truran, 13-17 Nov 200

Cost Analysis of eVTOL Configuration Design for an Air Ambulances System in Japan

Electric-vertical-takeoff-and-landing (eVTOL) aircraft, known as urban air mobility or flying cars, are being considered for widespread use as air taxis, emergency medical transportation, sightseeing vehicles, and rural transportation, owing to their reduced-size, low-cost, and low-noise characteristics. In this study, we conduct an interview at a Japanese hospital that currently uses a helicopter for medical emergencies to output the mission profile. Due to current battery-technology limitations, the new air ambulance, which will deliver a doctor to a patient, is conceived as having 2 passengers, including the pilot. Two eVTOL configurations are studied: a fixed-wing craft and a multi-rotor. The purpose of this study is to develop a cost model for a new air ambulance through a combination of 3 approaches: top-down, bottom-up, and parametric. The cost model is constructed to analyze the production cost of each configuration, broken down into the capital expense and direct operating cost. The result shows that the multi-rotor’s production cost is lower than the fixed-wing craft. The direct operating cost of a fixed-wing craft at high flight hours is higher than that of the multi-rotor. Scenario analysis shows a result that the capacity difference of a battery has a significant difference in the cost in the years 2020 and 2030 due to the high cost of battery replacement

Constraints on a vacuum energy from both SNIa and CMB temperature observations

We investigate the cosmic thermal evolution with a vacuum energy which decays into photon at the low-redshift. We assume that the vacuum energy is a function of the scale factor that increases toward the early universe. We put on the constraints using recent observations of both type Ia supernovae (SNIa) by Union-2 compilation and the cosmic microwave background (CMB) temperature at the range of the redshift 0.01 < z < 3. From SNIa, we find that the effects of a decaying vacuum energy on the cosmic expansion rate should be very small but could be possible for z < 1.5. On the other hand, we obtain the severe constraints for parameters from the CMB temperature observations. Although the temperature can be still lower than the case of the standard cosmological model, it should only affect the thermal evolution at the early epoch.Comment: 9 pages, 3 figures, 1 tables, submitted to Advances in Astronom

Relationship between sleep duration and clustering of metabolic syndrome diagnostic components

Sayuri Katano1, Yasuyuki Nakamura1,2, Aki Nakamura1, Yoshitaka Murakami3, Taichiro Tanaka4, Toru Takebayashi5, Akira Okayama6, Katsuyuki Miura2, Tomonori Okamura7, Hirotsugu Ueshima2, for HIPOP-OHP Research Group1Cardiovascular Epidemiology, Kyoto Women&amp;#39;s University, Kyoto, Japan; 2Department of Health Science, Shiga University of Medical Science, Otsu, Japan; 3Department of Medical Statistics, Shiga University of Medical Science, Otsu, Japan; 4Department of Health Sciences, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Japan; 5Department of Preventive Medicine and Public Health, School of Medicine, Keio University, Tokyo, Japan; 6The First Institute of Health Service, Japan Anti-Tuberculosis Association, Tokyo, Japan; 7Department of Preventive Cardiology, National Cardiovascular Center, Suita, JapanObjective: To examine the relation between sleep duration and metabolic syndrome (MetS).Methods: We examined the baseline data from 4356 healthy workers (3556 men and 800 women) aged 19&amp;ndash;69 years. The physical activity of each participant was classified according to the International Physical Activity Questionnaire (IPAQ). We defined four components of MetS diagnostic components in this study as follows: 1) high blood pressure (BP) systolic BP [SBP] &amp;ge; 130 mmHg, or diastolic BP [DBP] &amp;ge; 85 mmHg, or on medication; 2) dyslipidemia (high-density lipoprotein-cholesterol concentration ,40 mg/dL, or triglycerides concentration &amp;ge;150 mg/dL, or on medication; 3) impaired glucose tolerance (fasting blood sugar concentration &amp;ge; 110 mg/dL, or if less than 8 hours after meals &amp;ge; 140 mg/dL), or on medication; and 4) overweight (body mass index [BMI] &amp;ge; 25 kg/m2), or obesity (BMI &amp;ge; 30 kg/m2). There were 680 participants in the group, with sleep duration &amp;lt;6 hours (15.6%).Results: Those who had 0&amp;ndash;4 MetS diagnostic components, including overweight, accounted for 2159, 1222, 674, 255, and 46 participants, respectively, in the Poisson distribution. Poisson regression analysis revealed that independent factors that contributed to the number of MetS diagnostic components were being male (regression coefficient b = 0.752, P &amp;lt; 0.001), age (b = 0.026, P &amp;lt; 0.001), IPAQ classification (b = -0.238, P = 0.034), and alcohol intake (mL/day) (b = 0.018, P &amp;lt; 0.001). Short sleep duration (&amp;lt;6 hours) was also related to the number of MetS (b = 0.162, P &amp;lt; 0.001). The results of analyses with obesity component showed a similar association.Conclusion: Short sleep duration was positively associated with the number of MetS diagnostic components independent of other lifestyle habits.Keyword: short sleep duration, MetS diagnostic components, obesit

An All-Recombinant Protein-Based Culture System Specifically Identifies Hematopoietic Stem Cell Maintenance Factors.

Hematopoietic stem cells (HSCs) are considered one of the most promising therapeutic targets for the treatment of various blood disorders. However, due to difficulties in establishing stable maintenance and expansion of HSCs in vitro, their insufficient supply is a major constraint to transplantation studies. To solve these problems we have developed a fully defined, all-recombinant protein-based culture system. Through this system, we have identified hemopexin (HPX) and interleukin-1α as responsible for HSC maintenance in vitro. Subsequent molecular analysis revealed that HPX reduces intracellular reactive oxygen species levels within cultured HSCs. Furthermore, bone marrow immunostaining and 3D immunohistochemistry revealed that HPX is expressed in non-myelinating Schwann cells, known HSC niche constituents. These results highlight the utility of this fully defined all-recombinant protein-based culture system for reproducible in vitro HSC culture and its potential to contribute to the identification of factors responsible for in vitro maintenance, expansion, and differentiation of stem cell populations