Explore the vast range of titles available.

A bstract We discusses the charge asymmetry in B → D D ¯ K decays with an invariant mass of the D D ¯ pair near the Ψ(3770) resonance. Unlike Ψ(3770) decays in e + e − annihilation, in B + decays the probability of D 0 D ¯ 0 production is almost three times higher than D + D − . In B 0 decays, the ratio of these probabilities will be opposite. The effect is explained by the fact that, in B -meson decays, the D D ¯ pair is produced in a superposition of isoscalar and isovector states, and only in combination with K -mesons the total state has 1 / 2 isospin. We present a simple model in which the interference of the nonresonant isovector amplitude with the resonant isoscalar amplitude explains the experimental data.

Semileptonic decays of the B B ¯ pairs produced in the Υ ( 5 S ) can be used to find the relative probability of Υ ( 5 S ) → B s B ¯ s decays. This could be achieved by the study of time dependence of B -meson decays to the leptons of equal and opposite signs.

A bstract A method for measuring the average longitudinal polarization of the electron beam at an electron-positron collider operating near the J / ψ resonance is proposed. The method utilizes the differential cross-section of J / ψ → Λ → p π − Λ → p ¯ π + decay. It can be used to measure the average longitudinal polarization of electrons with the statistical precision better than 10 −3 at a Super Charm-Tau factory operating at the luminosity of 10 35 cm −2 s −1 . The method is discussed in the context of the weak mixing angle measurement in the same experiment.

Procedures of the Direct Simulation Monte Carlo method for weakly ionized flows around reentry vehicles are presented. For ionization and recombination reactions, expressions for the model dependence of the reaction probability on velocities and energies of reagents are derived. An algorithm of dissociative recombination is presented, whose computational efficiency is reached by bypassing the modeling of the interaction of electrons and heavy particles. An approach to the construction of a weighting scheme for elastic collisions and chemical reactions is described, which significantly increases the computational efficiency of the algorithm. An example of using these numerical models and procedures for studying a weakly ionized flow around a reentry capsule under typical reentry co-nditions is given. The computation results are compared to plasma parameters measured in flight experiments.

A bstract Model estimates are obtained for the influence of Coulomb effects on the ratio of the cross sections for the production of charged and neutral B B ¯ and B * B ¯ * pairs in e + e − annihilation. It is shown that the difference between the masses of charged and neutral mesons obtained under the assumption that this ratio is constant on a scale of the order of the beam energy spread can differ from the true one by δM ∼ 0 . 03 MeV at the energy of Υ(5 S ) and by δM ∼ 0 . 4 MeV at the energy of Υ(4 S ). Thus, the errors given in the PDG for the difference between the masses of charged and neutral B mesons, based on the results obtained at the energy of Υ(4 S ), are strongly underestimated. Similar measurements at the energy of Υ(5 S ) will have an order of magnitude smaller systematic shift for the mass difference. This circumstance should be taken into account when planning future experiments at the B factory in KEK.

The influenza epidemic in 2015-2016 in Russia is characterized by a sharp increase of influenza cases (beginning from the second week of 2016) with increased fatalities. Influenza was confirmed in 20 fatal cases registered among children (0-10 years), in 5 cases among pregnant women, and in 173 cases among elderly people (60 years and older). Two hundred and ninety nine people died from influenza were patients with some chronic problems. The overwhelming majority among the deceased (more than 98%) were not vaccinated against influenza. We isolated 109 influenza A(H1N1)pdm09 and one A(H3N2) virus strains from 501 autopsy material samples. The antigenic features of the strains were similar to the vaccine strains. A phylogenic analysis of hemagglutinin revealed that influenza A(H1N1)pdm09 virus strains belonged to 6B genetic group that had two main dominant subgroups during the 2015-2016 season. In Russia strains of the first group predominated. We registered an increased proportion of strains with D222G mutation in receptor-binding site. A herd immunity analysis carried out immediately prior to the epidemic showed that 34.4% blood sera samples collected in different regions of Russia were positive to A/California/07/09(H1N1)pdm09. We came to a conclusion that public awareness enhancement is necessary to reduce unreasonable refusals of vaccination.

The article deals with a typical technological map for the installation and dismantling of the formwork of a German manufacturer, the loads listed in the technological map according to the German regulatory documents are considered. The calculation of the loads acting on the formwork was performed in accordance with the Russian regulatory documents. A table comparing the results is presented from which it can be seen that the loads calculated in accordance with DIN 4421 and GOST R 52085-2003 for the same formwork differ in the values obtained. The conclusion is made that it is necessary to apply the Russian normative documents when calculating and using the formwork in the territory of the Russian Federation. In accordance with the Russian regulations, when calculating the distances between girders and contractions, calculations must be made for the two limiting states - from the strength conditions of the shield according to the carrying capacity and the shield strength by deformation. The distances between girders and contractions calculated in this way will meet the requirements of the normative documents of the Russian Federation. The article proposes a method for determining the distances between girders and contractions in two limiting states and shows the derivation of the formulas used in the calculations.

The removal of double-stranded RNA (dsRNA) contaminants during in vitro mRNA synthesis is one of the technological problems to be solved. Apparently, these contaminants are the result of the T7 RNA polymerase side activity. In this study, we used a modified method of mRNA purification based on the selective binding of dsRNA to cellulose in ethanol-containing buffer. It was shown both in vivo and in vitro that the cellulose-purified mRNA preparation leads neither to activation of the lymphocyte inflammatory marker CD69 nor to increased release of IFNα in mice, and does not contain impurities detectable by antibodies to dsRNA.

Mitochondrial forms account approximately 1–2% of all nonsyndromic cases of hearing loss (HL). One of the most common causative variants of mtDNA is the m.1555A > G variant of the MT-RNR1 gene (OMIM 561000). Currently the detection of the m.1555A > G variant of the MT-RNR1 gene is not included in all research protocols. In this study this variant was screened among 165 patients with HL from the Republic of Buryatia, located in the Baikal Lake region of Russia. In our study, the total contribution of the m.1555A > G variant to the etiology of HL was 12.7% (21/165), while the update global prevalence of this variant is 1.8% (863/47,328). The m.1555A > G variant was notably more prevalent in Buryat (20.2%) than in Russian patients (1.3%). Mitogenome analysis in 14 unrelated Buryat families carrying the m.1555A > G variant revealed a predominant lineage: in 13 families, a cluster affiliated with sub-haplogroup A5b (92.9%) was identified, while one family had the D5a2a1 lineage (7.1%). In a Russian family with the m.1555A > G variant the lineage affiliated with sub-haplogroup F1a1d was found. Considering that more than 90% of Buryat families with the m.1555A > G variant belong to the single maternal lineage cluster we conclude that high prevalence of this variant in patients with HL in the Baikal Lake region can be attributed to a founder effect.

A method for measuring cross sections at colliders for the case where the center-of-mass frame of colliding particles moves in the laboratory frame is proposed. Within this method, the energy dependence of the cross section is extracted from the angular distribution of interaction products. The method applied to the process is found to be sensitive. This method provides the possibility of studying the fine structure of the cross section near the threshold at scales much less than the energy spread of the beams used. Similar measurements may be implemented in experiments at the Super Charm-Tau Factory.