Accurate relativistic many-body calculations of van der Waals coefficients C_8 and C_10 for alkali-metal dimers

We consider long-range interactions between two alkali-metal atoms in their respective ground states. We extend the previous relativistic many-body calculations of C_6 dispersion coefficients [Phys.Rev. Lett. {\bf 82}, 3589 (1999)] to higher-multipole coefficients C_8 and C_10. A special attention is paid to usually omitted contribution of core-excited states. We calculate this contribution within relativistic random-phase approximation and demonstrate that for heavy atoms core excitations contribute as much as 10% to the dispersion coefficients. We tabulate results for both homonuclear and heteronuclear dimers and estimate theoretical uncertainties. The estimated uncertainties for C_8 coefficients range from 0.5% for Li_2 to 4% for Cs_2.Comment: 12 pages, submitted to Journal of Chemical Physic

Molecular-genetic analysis of Mycobacterium tuberculosis strains spread in different patient groups in St.Petersburg (Russia)

Molecular epidemiological features of M.tuberculosis strains spread among different patient groups in Russia is not studied well. The aim of our study was to compare genotypes of M.tuberculosis strains circulating among TB patients from different groups: homeless, HIV-infected, prisoners and general population of St.Petersburg citizens. 
One hundred fifty M.tuberculosis complex isolates from different TB patient groups were studied using spoligotyping method. 
The majority of studied M.tuberculosis isolates in all groups belonged to Beijing family (56% among homeless; 77% among HIV-infected; 60% among general population; 83% among prisoners). There were no significant difference in Beijing family prevalence among homeless patients, HIV/TB co-infected and general population of TB patients. The lowest genetic diversity of the pathogen was detected among imprisoned patients. 
Results of our study demonstrate that M.tuberculosis strains circulating among homeless and HIV-infected people are also spread among general population of St.Petersburg citizens. Thus, we have investigated participation of high-risk groups in the TB infection spread in the city

Hyperfine quenching of the metastable 3P0,2^3P_{0,2} states in divalent atoms

Hyperfine quenching rates of the lowest-energy metastable $^3P_0$ and $^3P_2$ states of Mg, Ca, Sr, and Yb atoms are computed. The calculations are carried out using ab initio relativistic many-body methods. The computed lifetimes may be useful for designing novel ultra-precise optical clocks and trapping experiments with the $3P_2$ fermionic isotopes. The resulting natural widths of the $^3P_0 -> ^1S_0$ clock transition are 0.44 mHz for $^{25}$Mg, 2.2 mHz for $^{43}$Ca, 7.6 mHz for $^{87}$Sr, 43.5 mHz for $^{171}$Yb, and 38.5 mHz for $^{173}$Yb. Compared to the bosonic isotopes, the lifetime of the $3P_2$ states in fermionic isotopes is noticeably shortened by the hyperfine quenching but still remains long enough for trapping experiments.Comment: 10 pages, 1 figure, submitted to Phys. Rev.

Reduction of negative impact on the geoenvironment using silica sol in road construction

Consumption and pollution of natural resources must be constantly compensated by their conservation, saving and restoration to create a balance in the ecosystem between man and nature. To solve this problem any construction process must be accompanied by geoecoprotective measures. The authors of the article suggest to use silica sol in the soils stabilization and reinforcement technology. Silica sol is a pure mineral product that has binding properties and neutralizing properties against some pollutants. This makes it suitable for soils reinforcement and also soils neutralization from pollutants such as heavy metals ions. The stabilization technology using technogenic soils and silica sol will conserve natural resources, improves the soil strength properties and neutralize them from pollutants

Alcohol misuse, drinking contexts and intimate partner violence in St. Petersburg, Russia: results from a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Alcohol misuse has been linked to intimate partner violence (IPV). However, this association is not usually examined in Russia. Moreover, more investigation is required as to whether specific drinking contexts are also associated with IPV. The objectives of this study are: to investigate whether alcohol misuse is associated with IPV and to further examine whether specific drinking contexts among drinkers are associated with IPV.</p> <p>Methods</p> <p>A questionnaire was used to collect information on demographics, health status, alcohol use, and violence involving sexual partners among 440 participants who were recruited from an STI (sexually transmitted infection) clinic center in St. Petersburg, Russia for a cross-sectional study from 2008 to 2009. Multivariate logistic regression was used for analysis.</p> <p>Results</p> <p>Overall, 47.0% participants were classified as misusing alcohol and 7.2% participants perpetrated IPV in the past three months. Participants with alcohol misuse were 3.28 times (OR: 3.28; 95% CI: 1.34-8.04) as likely as those without alcohol misuse to perpetrate IPV. Among participants who had consumed alcohol in the past three months, those who usually drank on the streets or in parks (OR: 5.62; 95% CI: 1.67-18.90) were more likely to perpetrate IPV.</p> <p>Conclusions</p> <p>Both alcohol misuse and certain drinking contexts (e.g., drinking on the streets or at parks) were associated with IPV. The association between drinking contexts and IPV needs further investigation, as do the underlying mechanisms for this association. IPV prevention initiatives might benefit from reducing alcohol misuse. Drinking contexts such as drinking on the streets or at parks as well as the factors related to the use of alcohol in these contexts may also need to be addressed.</p