Effects of Nitrogen Photoabsorption Cross Section Resolution on Minor Species Vertical Profiles in Titan's Upper Atmosphere

The significant variations in both measured and modeled densities of minor species in Titan's atmosphere call for the evaluation of possible influencing factors in photochemical modeling. The effect of nitrogen photoabsorption cross section selection on the modeled vertical profiles of minor species is analyzed here, with particular focus on C2H6 and HCN. Our results show a clear impact of cross sections used on all neutral and ion species studied. Affected species include neutrals and ions that are not primary photochemical products, including species that do not even contain nitrogen. The results indicate that photochemical models that employ low-resolution cross sections may significantly miscalculate the vertical profiles of minor species. Such differences are expected to have important implications for Titan's overall atmospheric structure and chemistry.NASA Outer Planet Research program NNH12ZDA001NInstitute for Computational Engineering and Sciences (ICES

Audit of stillbirths in a Nigerian teaching hospital Kuti

Objective: The purpose of this study is to classify the stillbirths (SBs) in our institution and to determine the avoidable contributors using a pro forma that was developed in our perinatal unit.Materials and Method: All mothers who delivered SBs at Obafemi Awolowo University Hospitals Complex Ile‑Ife, Nigeria, from April 2014 to August 2015 were the subjects of this study. At our weekly perinatal mortality meeting, every SB was reviewed in detail to determine the cause of death and identify gaps in the care. The causes of fetal death were classified using three classification systems – Simplified CODAC, ReCoDe, and our newly developed Ife Perinatal Death Classification System. Remote contributors to fetal demise were assigned using a purpose–designed “Avoidable Factor Proforma” A SB was deemed avoidable if one or more factors were identified.Results: The total number of deliveries during the study was 2,142 with 109 SBs giving a gross SB rate of 51/1000 total births. The SB rate was significantly lower among booked patients than their unbooked counterparts (15 vs. 140 per 1000; P < 0.005). Antepartum death constituted 82.6% of SB among booked patients compared to 41.2% in the unbooked. The most common cause of SB among booked mother was intrauterine growth restriction (21.7%) while obstructed labor (23.3%) was the leading cause among unbooked mothers. Using our classification system, only 3.8% of SBs were unexplained, as against 5.7% for ReCode, and 26.4% for Simplified CODAC. Majority (81.7%) of the SBs were avoidable; and the most common avoidable factor was deficiency in health care. Access to the point of care was not associated with any of the avoidable deaths.Conclusion: Our SB rate remains unacceptably high, with a preponderance of antepartum deaths among booked patients. Majority of the SBs are avoidable dictating the need for training in modern methods of fetal surveillance and improved efficiency of our health‑delivery systems.Keywords: Avoidable Factors , Classification,. Stillbirth

Quality evaluation of fresh and bloomed filled chocolates in House of Quality

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Anomalous Fermion Number Non-Conservation on the Lattice

The anomaly for the fermion number current is calculated on the lattice in a simple prototype model with an even number of fermion doublets.Comment: 6 pages, CERN-TH.6717/92. Contribution to the Amsterdam Lattice '92 Conferenc

Observation of Anomalous Internal Pair Creation in 8^8Be: A Possible Signature of a Light, Neutral Boson

Electron-positron angular correlations were measured for the isovector magnetic dipole 17.6 MeV state ($J^\pi=1^+$, $T=1$) $\rightarrow$ ground state ($J^\pi=0^+$, $T=0$) and the isoscalar magnetic dipole 18.15 MeV ($J^\pi=1^+$, $T=0$) state $\rightarrow$ ground state transitions in $^{8}$Be. Significant deviation from the internal pair creation was observed at large angles in the angular correlation for the isoscalar transition with a confidence level of $> 5\sigma$. This observation might indicate that, in an intermediate step, a neutral isoscalar particle with a mass of 16.70$\pm0.35$ (stat)$\pm 0.5$ (sys) MeV$/c^2$ and $J^\pi = 1^+$ was created.Comment: 5 pages, 5 figure

Spontaneous symmetry breaking on the lattice generated by Yukawa interaction

We study by numerical simulation a lattice Yukawa model with naive fermions at intermediate values of the Yukawa coupling $y$ when the nearest neighbour coupling \kp of the scalar field $\Phi$ is very weakly ferromagnetic (\kp \approx 0) or even antiferromagnetic ($\kappa < 0$) and the nonvanishing value of \vev is generated by the Yukawa interaction. The renormalized Yukawa coupling $y_R$ achieves here its maximal value and this $y$-region is thus of particular importance for lattice investigations of strong Yukawa interaction. However, here the scalar field propagators have a very complex structure caused by fermion loop corrections and by the proximity of phases with antiferromagnetic properties. We develop methods for analyzing these propagators and for extracting the physical observables. We find that going into the negative \kp region, the scalar field renormalization constant becomes small and $y_R$ does not seem to exceed the unitarity bound, making the existence of a nontrivial fixed point in the investigated Yukawa model quite unlikely.Comment: 22 pages plus 13 figure

A protosolar nebula origin for the ices agglomerated by Comet 67P/Churyumov-Gerasimenko

The nature of the icy material accreted by comets during their formation in the outer regions of the protosolar nebula is a major open question in planetary science. Some scenarios of comet formation predict that these bodies agglomerated from crystalline ices condensed in the protosolar nebula. Concurrently, alternative scenarios suggest that comets accreted amorphous ice originating from the interstellar cloud or from the very distant regions of the protosolar nebula. On the basis of existing laboratory and modeling data, we find that the N$_2$/CO and Ar/CO ratios measured in the coma of the Jupiter family comet 67P/Churyumov-Gerasimenko by the ROSINA instrument aboard the European Space Agency's Rosetta spacecraft match those predicted for gases trapped in clathrates. If these measurements are representative of the bulk N$_2$/CO and Ar/CO ratios in 67P/Churyumov-Gerasimenko, it implies that the ices accreted by the comet formed in the nebula and do not originate from the interstellar medium, supporting the idea that the building blocks of outer solar system bodies have been formed from clathrates and possibly from pure crystalline ices. Moreover, because 67P/Churyumov-Gerasimenko is impoverished in Ar and N$_2$, the volatile enrichments observed in Jupiter's atmosphere cannot be explained solely via the accretion of building blocks with similar compositions and require an additional delivery source. A potential source may be the accretion of gas from the nebula that has been progressively enriched in heavy elements due to photoevaporation.Comment: The Astrophysical Journal Letters, in pres