The B-ring's surface mass density from hidden density waves: Less than meets the eye?

Saturn's B ring is the most opaque ring in our solar system, but many of its fundamental parameters, including its total mass, are not well constrained. Spiral density waves generated by mean-motion resonances with Saturn's moons provide some of the best constraints on the rings' mass density, but detecting and quantifying such waves in the B ring has been challenging because of this ring's high opacity and abundant fine-scale structure. Using a wavelet-based analyses of 17 occultations of the star gamma Crucis observed by the Visual and Infrared Mapping Spectrometer (VIMS) onboard the Cassini spacecraft, we are able to examine five density waves in the B ring. Two of these waves are generated by the Janus 2:1 and Mimas 5:2 Inner Lindblad Resonances at 96,427 km and 101,311 km from Saturn's center, respectively. Both of these waves can be detected in individual occultation profiles, but the multi-profile wavelet analysis reveals unexpected variations in the pattern speed of the Janus 2:1 wave that might arise from the periodic changes in Janus' orbit. The other three wave signatures are associated with the Janus 3:2, Enceladus 3:1 and Pandora 3:2 Inner Lindblad Resonances at 115,959 km, 115,207 km and 108,546 km. These waves are not visible in individual profiles, but structures with the correct pattern speeds can be detected in appropriately phase-corrected average wavelets. Estimates of the ring's surface mass density derived from these five waves fall between 40 and 140 g/cm^2, even though the ring's optical depth in these regions ranges from 1.5 to almost 5. This suggests that the total mass of the B ring is most likely between one-third and two-thirds the mass of Saturn's moon Mimas.Comment: 40 Pages, 21 Figures, Accepted for publication in Icarus, a few typos fixe

Alcohol consumption is associated with increased all-cause mortality in Russian men and women: a cohort study based on the mortality of relatives

Objectives: To examine the relationships between frequency of alcohol consumption and of binge drinking and adult mortality in Russian men and women.Methods : Using modified indirect demographic techniques, a convenience cohort was constructed based on survey respondents? information about their close relatives. A random sample general population of the Russian Federation of 7172 respondents (response rate 61%) provided information on 10475 male and 3129 female relatives, including age, vital status and frequency of alcohol consumption and binge drinking. These relatives formed the cohort analysed in this report. The outcome measure was all-cause mortality after the age of 30 years.Findings: There was a strong linear relationship between frequency of drinking and of binge drinking and all-cause mortality in men; after controlling for smoking and calendar period of birth, the relative risk of death in daily drinkers compared to occasional drinkers was 1.52 (95% CI 1.33 ?1.75). Male binge drinkers had higher mortality than drinkers who did not binge, which persisted after adjustment for drinking frequency (adjusted RR 1.09 (1.00-1.19). In women, the increased mortality was confined to a small group of those who binged at least once a month (adjusted relative risk 2.68, 1.54-4.66). Conclusions: The results suggest a positive association between alcohol and mortality in Russia. There was no evidence for the protective effect of drinking seen in western populations. Alcohol appears to have contributed to the high long-term mortality rates in Russian men, but it is unlikely to be a major cause of female mortality. Objectives: To examine the relationships between frequency of alcohol consumption and of binge drinking and adult mortality in Russian men and women.Methods : Using modified indirect demographic techniques, a convenience cohort was constructed based on survey respondents? information about their close relatives. A random sample general population of the Russian Federation of 7172 respondents (response rate 61%) provided information on 10475 male and 3129 female relatives, including age, vital status and frequency of alcohol consumption and binge drinking. These relatives formed the cohort analysed in this report. The outcome measure was all-cause mortality after the age of 30 years.Findings: There was a strong linear relationship between frequency of drinking and of binge drinking and all-cause mortality in men; after controlling for smoking and calendar period of birth, the relative risk of death in daily drinkers compared to occasional drinkers was 1.52 (95% CI 1.33 ?1.75). Male binge drinkers had higher mortality than drinkers who did not binge, which persisted after adjustment for drinking frequency (adjusted RR 1.09 (1.00-1.19). In women, the increased mortality was confined to a small group of those who binged at least once a month (adjusted relative risk 2.68, 1.54-4.66). Conclusions: The results suggest a positive association between alcohol and mortality in Russia. There was no evidence for the protective effect of drinking seen in western populations. Alcohol appears to have contributed to the high long-term mortality rates in Russian men, but it is unlikely to be a major cause of female mortality

Low complexity method for large-scale self-consistent ab initio electronic-structure calculations without localization

A novel low complexity method to perform self-consistent electronic-structure calculations using the Kohn-Sham formalism of density functional theory is presented. Localization constraints are neither imposed nor required thereby allowing direct comparison with conventional cubically scaling algorithms. The method has, to date, the lowest complexity of any algorithm for an exact calculation. A simple one-dimensional model system is used to thoroughly test the numerical stability of the algorithm and results for a real physical system are also given

Regional labor force growth: mix of native, immigrant workers varies

Immigrants