Propane-1,3-diaminium bis­(perchlorate)–18-crown-6 (1/2)

In the title compound, C3H12N2 2+·2ClO4 −·2C12H24O6, the central C atom of the propane-1,3-diammonium cation is located on a twofold rotation axis and the two terminal –NH3 groups insert into the crown rings through N—H⋯O hydrogen bonding, resulting in the formation of a 1:2 supra­molecular [(C3H12N2)·(C12H24O6)2]+ complex. The perchlorate anion links with the supra­molecular complex via weak C—H⋯O hydrogen bonding

Topological Strings and Quantum Spectral Problems

We consider certain quantum spectral problems appearing in the study of local Calabi-Yau geometries. The quantum spectrum can be computed by the Bohr-Sommerfeld quantization condition for a period integral. For the case of small Planck constant, the periods are computed perturbatively by deformation of the Omega background parameters in the Nekrasov-Shatashvili limit. We compare the calculations with the results from the standard perturbation theory for the quantum Hamiltonian. There have been proposals in the literature for the non-perturbative contributions based on singularity cancellation with the perturbative contributions. We compute the quantum spectrum numerically with some high precisions for many cases of Planck constant. We find that there are also some higher order non-singular non-perturbative contributions, which are not captured by the singularity cancellation mechanism. We fix the first few orders formulas of such corrections for some well known local Calabi-Yau models.Comment: 47 pages, 3 figures. v2: journal version, typos correcte

Socioeconomic Determinants of Mortality in Taiwan: Combining Individual Data and Aggregate Data

There is a very large literature that examines the relationship between health and income. Two main hypotheses have been investigated: the relative income hypothesis and the absolute income hypothesis. Most of previous studies that used mortality data have been criticized for estimating an aggregate model that does not account for non-linear links between health and income at the individual level. In this paper we follow a novel approach to avoid this bias, combining aggregate mortality data with individual level data on socio-economic characteristics. We test the relative and absolute income hypotheses using county level mortality data from Life Statistic of Department of Health and individual level data from Taiwan census FIES for 1976-2003. We find that there is no strong evidence supporting either hypothesis in the case of the general population. In contrast, we find strong evidence that education does have significant effects on individuals’ health and the estimates are not sensitive to income equivalent scales.mortality, relative income hypothesis, aggregation bias