Relativistic eikonal description of A(p,pN) reactions

The authors present a relativistic and cross-section factorized framework for computing quasielastic A(p,pN) observables at intermediate and high energies. The model is based on the eikonal approximation and can accomodate both optical potentials and the Glauber method for dealing with the initial- and final-state interactions (IFSI). At lower nucleon energies, the optical-potential philosophy is preferred, whereas at higher energies the Glauber method is more natural. This versatility in dealing with the IFSI allows one to describe A(p,pN) reactions in a wide energy range. Most results presented here use optical potentials as this approach is argued to be the optimum choice for the kinematics of the experiments considered in the present paper. The properties of the IFSI factor, a function wherein the entire effect of the IFSI is contained, are studied in detail. The predictions of the presented framework are compared with two kinematically different experiments. First, differential cross sections for quasielastic proton scattering at 1 GeV off 12C, 16O, and 40Ca target nuclei are computed and compared to data from PNPI. Second, the formalism is applied to the analysis of a 4He(p,2p) experiment at 250 MeV. The optical-potential calculations are found to be in good agreement with the data from both experiments, showing the reliability of the adopted model in a wide energy range.Comment: 34 pages, 14 figures, accepted for publication in Phys. Rev.

ABOUT METHODS OF SEISMIC ANALYSIS OF UNDERGROUND STRUCTURES

As is known, underground facilities are an integral part of the infrastructure of modern society. These objects have some specific characteristics such as complex construction, high cost, long life cycle, etc. Once it is destroyed, the direct and indirect losses are more seriousness than the general structure in the ground. Under-ground facilities built in areas subject to earthquake activity must withstand both seismic and static loading. Therefore, it is very important to carry on the seismic design of the underground structure in a safe and economi-cal way. The distinctive paper presents a summary of the current state of seismic analysis for underground struc-tures. Classification and brief overview of methods of seismic analysis of underground structures (force-based methods, displacement-based methods, numerical methods of seismic analysis of coupled system “soil – under-ground structure”) are presented, problems of soil-structure interaction are under consideration as well. So-called static finite element method with substructure technique for seismic analysis of underground structures is de-scribed

Measurement of tensor analyzing powers in deuteron photodisintegration

New accurate measurement of tensor analyzing powers T20, T21 and T22 in deuteron photodisintegration has been performed. Wide-aperture non-magnetic detectors allowed to cover broad kinematic ranges in a single setup: photon energy = 25 to 600 MeV, proton emission angle in CM = 24 to 48 deg. and 70 to 102 deg. New data provide a significant improvement of a few existing measurements. The angular dependency of the tensor asymmetries in deuteron photodisintegration is extracted for the first time.Comment: 4 pages, 5 figures, submitted to Phys. Rev. Let

Probing coherent charmonium photoproduction off light nuclei at medium energies

We demonstrate how the elementary amplitudes $\gamma N\to \Psi N$, the amplitude of the nondiagonal $J/\psi N\Leftrightarrow \psi' N$ transition, and the total $J/\psi N$ and $\psi' N$ cross sections can be determined from measurements of the coherent $J/\psi$ and $\psi'$ photoproduction off light nuclei at moderate energies. For this purpose we provide a detailed numerical analysis of the coherent charmonium photoproduction off silicon within the generalized vector dominance model (GVDM) adjusted to account for the physics of charmonium models and color transparency phenomenon.Comment: 8 pages, 5 figures (color

Radio-frequency discharges in Oxygen. Part 1: Modeling

In this series of three papers we present results from a combined experimental and theoretical effort to quantitatively describe capacitively coupled radio-frequency discharges in oxygen. The particle-in-cell Monte-Carlo model on which the theoretical description is based will be described in the present paper. It treats space charge fields and transport processes on an equal footing with the most important plasma-chemical reactions. For given external voltage and pressure, the model determines the electric potential within the discharge and the distribution functions for electrons, negatively charged atomic oxygen, and positively charged molecular oxygen. Previously used scattering and reaction cross section data are critically assessed and in some cases modified. To validate our model, we compare the densities in the bulk of the discharge with experimental data and find good agreement, indicating that essential aspects of an oxygen discharge are captured.Comment: 11 pages, 10 figure

Fluorescence-Tagged Transgenic Lines Reveal Genetic Defects in Pollen Growth—Application to the Eif3 Complex

BACKGROUND: Mutations in several subunits of eukaryotic translation initiation factor 3 (eIF3) cause male transmission defects in Arabidopsis thaliana. To identify the stage of pollen development at which eIF3 becomes essential it is desirable to examine viable pollen and distinguish mutant from wild type. To accomplish this we have developed a broadly applicable method to track mutant alleles that are not already tagged by a visible marker gene through the male lineage of Arabidopsis. METHODOLOGY/PRINCIPAL FINDINGS: Fluorescence tagged lines (FTLs) harbor a transgenic fluorescent protein gene (XFP) expressed by the pollen-specific LAT52 promoter at a defined chromosomal position. In the existing collection of FTLs there are enough XFP marker genes to track nearly every nuclear gene by virtue of its genetic linkage to a transgenic marker gene. Using FTLs in a quartet mutant, which yields mature pollen tetrads, we determined that the pollen transmission defect of the eif3h-1 allele is due to a combination of reduced pollen germination and reduced pollen tube elongation. We also detected reduced pollen germination for eif3e. However, neither eif3h nor eif3e, unlike other known gametophytic mutations, measurably disrupted the early stages of pollen maturation. CONCLUSION/SIGNIFICANCE: eIF3h and eIF3e both become essential during pollen germination, a stage of vigorous translation of newly transcribed mRNAs. These data delimit the end of the developmental window during which paternal rescue is still possible. Moreover, the FTL collection of mapped fluorescent protein transgenes represents an attractive resource for elucidating the pollen development phenotypes of any fine-mapped mutation in Arabidopsis

Measurement of Angular Distributions and R= sigma_L/sigma_T in Diffractive Electroproduction of rho^0 Mesons

Production and decay angular distributions were extracted from measurements of exclusive electroproduction of the rho^0(770) meson over a range in the virtual photon negative four-momentum squared 0.5< Q^2 <4 GeV^2 and the photon-nucleon invariant mass range 3.8< W <6.5 GeV. The experiment was performed with the HERMES spectrometer, using a longitudinally polarized positron beam and a ^3He gas target internal to the HERA e^{+-} storage ring. The event sample combines rho^0 mesons produced incoherently off individual nucleons and coherently off the nucleus as a whole. The distributions in one production angle and two angles describing the rho^0 -> pi+ pi- decay yielded measurements of eight elements of the spin-density matrix, including one that had not been measured before. The results are consistent with the dominance of helicity-conserving amplitudes and natural parity exchange. The improved precision achieved at 47 GeV, reveals evidence for an energy dependence in the ratio R of the longitudinal to transverse cross sections at constant Q^2.Comment: 15 pages, 15 embedded figures, LaTeX for SVJour(epj) document class Revision: Fig. 15 corrected, recent data added to Figs. 10,12,14,15; minor changes to tex

Nuclear Polarization of Molecular Hydrogen Recombined on a Non-metallic Surface

The nuclear polarization of $\mathrm{H}_2$ molecules formed by recombination of nuclear polarized H atoms on the surface of a storage cell initially coated with a silicon-based polymer has been measured by using the longitudinal double-spin asymmetry in deep-inelastic positron-proton scattering. The molecules are found to have a substantial nuclear polarization, which is evidence that initially polarized atoms retain their nuclear polarization when absorbed on this type of surfac

Лекарственный анафилактический шок

Among the major etiological factors that can cause an anaphylactic shock (AS), drugs account for 31.2-46.5%.Purpose of the work was to identify factors associated with a high AS risk based on 2010-2018 records made in the Republic of Crimea.Materials and methods. The objects of the study were 112 information reports about adverse reactions (AR) to medicine remedies (MR), which were recorded in the regional database of spontaneous information reports—ARCAD — in the Republic of Crimea during 2010-2018. A retrospective analysis of drug-induced AS cases has been carried out for the following indicators: intake and route of administration of drugs, gender, age, history of allergies.Results of the study have shown that antimicrobial drugs, local anesthetics, analgesics-antipyretics, X-ray contrast iodine-containing substances, and non-steroidal anti-inflammatory drugs featured the highest AS incidence. Most frequently, AS cases were observed in patients aged 31 to 60 years, with no significant differences between men (57 cases) and women (54 cases). In one case the patient's gender was missed or not stated.The leader in AS incidence is Ceftriaxone, which application was associated with 22 cases of such AR. In 87 cases, AS was found associated with parenteral administration drugs, the intravenous route of administration being predominant (44 cases). In 97 cases, development of drug-induced AS was life-threatening and required emergency pharmacotherapy; 8 reports contained a lethal outcome record.Conclusions. Attention should be paid to high incidence, severity, and instant progression rate of adverse reactions in the form of AS. Considering the AS progression rate and facts of ignored past history of drugs and allergies, as well as pharmacological correction errors, additional educational events are worth conducting for physicians specializing in different fields.Среди основных этиологических факторов, способных вызвать развитие анафилактического шока (АШ) у пациентов, лекарственные препараты составляют 31,2-46,5%.Цель работы — выявление факторов, ассоциированных с повышенным риском развития АШ, зарегистрированного в 2010-2018 гг. у пациентов в Республике Крым.Материалы и методы. Объектами исследования стали 112 карт-извещений о нежелательных реакциях (НР) лекарственных средств (ЛС), зарегистрированных в региональной базе спонтанных сообщений ARCADe в Республике Крым за период 2010-2018 гг. На основании карт-извещений провели ретроспективный анализ случаев возникновения лекарственного АШ по следующим показателям: прием и способ введения препаратов, пол, возраст, аллергологический анамнез.Результаты исследования показали, что лидерами по частоте развития АШ являлись противомикробные препараты местные анестетики, анальгетики-антипиретики, рентгеноконтрастные йодсодержащие вещества и нестероидные противовоспалительные препараты. Случаи развития АШ чаще всего наблюдали у пациентов в возрасте от 31 до 60 лет, у мужчин с большей частотой (57 случаев), чем у женщин (54 случая). В одном случае указания на пол пациента отсутствовали. Лидером по частоте развития случаев АШ являлся цефтриаксон, с применением которого было ассоциировано 22 случая таких НР Выявили, что в 87 случаях АШ развивался на фоне парентерального введения препаратов, среди которых преобладал внутривенный путь введения (44 случая). Развитие лекарственного АШ в 97 случаях представляло собой угрозу жизни пациента и требовало неотложной фармакотерапии, в 8 картах-извещениях содержалась информация о летальном исходе для пациентов.Выводы. Стоит обратить внимание на высокую частоту, серьезность и мгновенную скорость развития нежелательных реакций в виде АШ. Учитывая скорость развития АШ и факты игнорирования лекарственного и аллергологического анамнеза, ошибки медикаментозной коррекции следует рассмотреть возможность проведения дополнительных образовательных мероприятий для врачей разных специальностей

Transcriptome analysis of haploid male gametophyte development in Arabidopsis

BACKGROUND: The haploid male gametophyte generation of flowering plants consists of two- or three-celled pollen grains. This functional specialization is thought to be a key factor in the evolutionary success of flowering plants. Moreover, pollen ontogeny is also an attractive model in which to dissect cellular networks that control cell growth, asymmetric cell division and cellular differentiation. Our objective, and an essential step towards the detailed understanding of these processes, was to comprehensively define the male haploid transcriptome throughout development. RESULTS: We have developed staged spore isolation procedures for Arabidopsis and used Affymetrix ATH1 genome arrays to identify a total of 13,977 male gametophyte-expressed mRNAs, 9.7% of which were male-gametophyte-specific. The transition from bicellular to tricellular pollen was accompanied by a decline in the number of diverse mRNA species and an increase in the proportion of male gametophyte-specific transcripts. Expression profiles of regulatory proteins and distinct clusters of coexpressed genes were identified that could correspond to components of gametophytic regulatory networks. Moreover, integration of transcriptome and experimental data revealed the early synthesis of translation factors and their requirement to support pollen tube growth. CONCLUSIONS: The progression from proliferating microspores to terminally differentiated pollen is characterized by large-scale repression of early program genes and the activation of a unique late gene-expression program in maturing pollen. These data provide a quantum increase in knowledge concerning gametophytic transcription and lay the foundations for new genomic-led studies of the regulatory networks and cellular functions that operate to specify male gametophyte development