105 research outputs found

    The mitochondrial gene order and CYTB gene evolution in insects

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    Over millions of years of evolution, the genomes of modern insects have accumulated a significant number of mutations, which often can lead up a blind alley when carrying out phylogenetic research. Genomic differences between some representatives belonging to the same family or group are often so great that they demand using nonconventional methods of the phylogenetic analysis. It is known that molecular evolution goes by the way of not only single nucleotide substitutions, but also by larger genomic reorganizations, such as insertion or deletion of large genome fragments, and even changing the order of genes. Mitochondrial DNA genes (mtDNA) are quite often used as markers for phylogenetic research into many organisms including arthropods, because mtDNA is multicopied, is inherited maternally, does not undergo recombination and accumulates mutations quickly enough (relative to the nuclear genome). To date, a large number of full nucleotide sequences of mitogenomes (thousands of organisms) has been deposited in public databases; however, their phylogenetic analysis has obstacles, especially for representatives of the insects (Insecta), whose evolution takes a considerable part of geological time. In this work we describe the application and a comparison of two ways of the phylogenetic analysis for different groups of insects. The first method uses the variability of the nucleotide sequence of mtDNA, and the second one analyses the order of genes in full mitochondrial genomes of insects that can be used as an additional marker in phylogenetic research into representatives of the order Hymenoptera

    СИНТЕЗ КОНЪЮГАТОВ ОЛИГОНУКЛЕОТИДОВ С ПРОИЗВОДНЫМИ 11,11-D2-ЛИНОЛЕВОЙ КИСЛОТЫ ПО РЕАКЦИИ АЗИД-АЛКИНОВОГО ЦИКЛОПРИСОЕДИНЕНИЯ

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    A new approach to the synthesis of oligonucleotide-fatty acid conjugates is reported. It is based on Cu-catalyzed reaction between azide oligonucleotides and fatty acid derivatives with terminal triple bond (CuAAC). To demonstrate this approach, five derivatives of 11,11-D2-linoleic acid containing terminal alkyne group at different parts of the molecule were synthesized. A method of conjugation of alkyne 11,11-D2-linoleic acid with azide oligonucleotide T20 is developed, and the conditions (time, concentration of Cu catalyst, excess of alkyne reagent, composition of the solvent, etc.) are optimized. These conjugates are stable in biological media, have increased permeability through the cell membranes and can be used in gene therapy. Предложен новый подход к синтезу конъюгатов олигонуклеотидов и жирных кислот, основанный на медь-катализируемой реакции циклоприсоединения азидсодержащих олигонуклеотидов к производным жирных кислот с терминальной тройной связью (CuAAC). Для демонстрации этого подхода осуществлен синтез пяти производных 11,11-D2-линолевой кислоты, содержащих концевую тройную связь в различных частях молекулы. Разработана методика их конъюгации с азидсодержащим модельным олигонуклеотидом Т20, проверено влияние различных условий (времени, концентрации катализатора, избытка алкинсодержащего реагента, состава растворителя и др.) на выход продукта. Такие конъюгаты устойчивы в биологических средах, обладают повышенной способностью проникать в клетки и могут найти применение в качестве средств генной терапии.

    Methamphetamine withdrawal induces activation of CRF neurons in the brain stress system in parallel with an increased activity of cardiac sympathetic pathways.

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    Methamphetamine (METH) addiction is a major public health problem in some countries. There is evidence to suggest that METH use is associated with increased risk of developing cardiovascular problems. Here, we investigated the effects of chronic METH administration and withdrawal on the activation of the brain stress system and cardiac sympathetic pathways. Mice were treated with METH (2 mg/kg, i.p.) for 10 days and left to spontaneous withdraw for 7 days. The number of corticotrophin-releasing factor (CRF), c-Fos, and CRF/c-Fos neurons was measured by immunohistochemistry in the paraventricular nucleus of the hypothalamus (PVN) and the oval region of the bed nucleus of stria terminalis (ovBNST), two regions associated with cardiac sympathetic control. In parallel, levels of catechol-o-methyl-transferase (COMT), tyrosine hydroxylase (TH), and heat shock protein 27 (Hsp27) were measured in the heart. In the brain, chronic-METH treatment enhanced the number of c-Fos neurons and the CRF neurons with c-Fos signal (CRF+/c-Fos+) in PVN and ovBNST. METH withdrawal increased the number of CRF+neurons. In the heart, METH administration induced an increase in soluble (S)-COMT and membrane-bound (MB)-COMT without changes in phospho (p)-TH, Hsp27, or pHsp27. Similarly, METH withdrawal increased the expression of S- and MB-COMT. In contrast to chronic treatment, METH withdrawal enhanced levels of (p)TH and (p)Hsp27 in the heart. Overall, our results demonstrate that chronic METH administration and withdrawal activate the brain CRF systems associated with the heart sympathetic control and point towards a METH withdrawal induced activation of sympathetic pathways in the heart. Our findings provide further insight in the mechanism underlining the cardiovascular risk associated with METH use and proposes targets for its treatment

    Collins and Sivers transverse-spin asymmetries in inclusive muoproduction of ρ0\rho^0 mesons

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    The production of vector mesons in deep inelastic scattering is an interesting yet scarsely explored channel to study the transverse spin structure of the nucleon and the related phenomena. The COMPASS collaboration has performed the first measurement of the Collins and Sivers asymmetries for inclusively produced ρ0\rho^0 mesons. The analysis is based on the data set collected in deep inelastic scattering in 20102010 using a 160GeV/c160\,\,\rm{GeV}/c μ+\mu^+ beam impinging on a transversely polarized NH3\rm{NH}_3 target. The ρ0\rho^{0} mesons are selected from oppositely charged hadron pairs, and the asymmetries are extracted as a function of the Bjorken-xx variable, the transverse momentum of the pair and the fraction of the energy zz carried by the pair. Indications for positive Collins and Sivers asymmetries are observed

    High-statistics measurement of Collins and Sivers asymmetries for transversely polarised deuterons

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    New results are presented on a high-statistics measurement of Collins and Sivers asymmetries of charged hadrons produced in deep inelastic scattering of muons on a transversely polarised 6^6LiD target. The data were taken in 2022 with the COMPASS spectrometer using the 160 \gevv\ muon beam at CERN, balancing the existing data on transversely polarised proton targets. The first results from about two-thirds of the new data have total uncertainties smaller by up to a factor of three compared to the previous deuteron measurements. Using all the COMPASS proton and deuteron results, both the transversity and the Sivers distribution functions of the uu and dd quark, as well as the tensor charge in the measured xx-range are extracted. In particular, the accuracy of the dd quark results is significantly improved

    Spin Density Matrix Elements in Exclusive ρ0\rho ^0 Meson Muoproduction

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    We report on a measurement of Spin Density Matrix Elements (SDMEs) in hard exclusive ρ0\rho ^0 meson muoproduction at COMPASS using 160~GeV/cc polarised μ+ \mu ^{+} and μ \mu ^{-} beams impinging on a liquid hydrogen target. The measurement covers the kinematic range 5.0~GeV/c2c^2 <W<< W < 17.0~GeV/c2c^2, 1.0 (GeV/cc)2^2 <Q2<< Q^2 < 10.0 (GeV/cc)2^2 and 0.01 (GeV/cc)2^2 <pT2<< p_{\rm{T}}^2 < 0.5 (GeV/cc)2^2. Here, WW denotes the mass of the final hadronic system, Q2Q^2 the virtuality of the exchanged photon, and pTp_{\rm{T}} the transverse momentum of the ρ0\rho ^0 meson with respect to the virtual-photon direction. The measured non-zero SDMEs for the transitions of transversely polarised virtual photons to longitudinally polarised vector mesons (γTVL\gamma^*_T \to V^{ }_L) indicate a violation of ss-channel helicity conservation. Additionally, we observe a dominant contribution of natural-parity-exchange transitions and a very small contribution of unnatural-parity-exchange transitions, which is compatible with zero within experimental uncertainties. The results provide important input for modelling Generalised Parton Distributions (GPDs). In particular, they may allow one to evaluate in a model-dependent way the role of parton helicity-flip GPDs in exclusive ρ0\rho ^0 production

    Double J/ψJ/\psi production in pion-nucleon scattering at COMPASS

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    We present the study of the production of double J/ψJ/\psi mesons using COMPASS data collected with a 190 GeV/cc π\pi^- beam scattering off NH3_{3}, Al and W targets. Kinematic distributions of the collected double J/ψJ/\psi events are analysed, and the double J/ψJ/\psi production cross section is estimated for each of the COMPASS targets. The results are compared to predictions from single- and double-parton scattering models as well as the pion intrinsic charm and the tetraquark exotic resonance hypotheses. It is demonstrated that the single parton scattering production mechanism gives the dominant contribution that is sufficient to describe the data. An upper limit on the double intrinsic charm content of pion is evaluated. No significant signatures that could be associated with exotic tetraquarks are found in the double J/ψJ/\psi mass spectrum.Comment: 12 pages, 4 figure

    Measurement of Energy Correlators inside Jets and Determination of the Strong Coupling Formula Presented

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    Energy correlators that describe energy-weighted distances between two or three particles in a hadronic jet are measured using an event sample of s\sqrt{s}=13 TeV proton-proton collisions collected by the CMS experiment and corresponding to an integrated luminosity of 36.3 fb1^{−1}. The measured distributions are consistent with the trends in the simulation that reveal two key features of the strong interaction: confinement and asymptotic freedom. By comparing the ratio of the measured three- and two-particle energy correlator distributions with theoretical calculations that resum collinear emissions at approximate next-to-next-to-leading-logarithmic accuracy matched to a next-to-leading-order calculation, the strong coupling is determined at the Z boson mass: αS_S (mZ_Z)=0.1229 0.00400.0050\frac{0.0040}{-0.0050} , the most precise αS_SmZ_Z value obtained using jet substructure observable

    Search for heavy neutral leptons in final states with electrons, muons, and hadronically decaying tau leptons in proton-proton collisions at s \sqrt{s} = 13 TeV

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    A search for heavy neutral leptons (HNLs) of Majorana or Dirac type using proton-proton collision data at = 13 TeV is presented. The data were collected by the CMS experiment at the CERN LHC and correspond to an integrated luminosity of 138 fb−1. Events with three charged leptons (electrons, muons, and hadronically decaying tau leptons) are selected, corresponding to HNL production in association with a charged lepton and decay of the HNL to two charged leptons and a standard model (SM) neutrino. The search is performed for HNL masses between 10 GeV and 1.5 TeV. No evidence for an HNL signal is observed in data. Upper limits at 95% confidence level are found for the squared coupling strength of the HNL to SM neutrinos, considering exclusive coupling of the HNL to a single SM neutrino generation, for both Majorana and Dirac HNLs. The limits exceed previously achieved experimental constraints for a wide range of HNL masses, and the limits on tau neutrino coupling scenarios with HNL masses above the W boson mass are presented for the first time

    Measurement of the polarizations of prompt and non-prompt J/ψ and ψ (2S) mesons produced in pp collisions at s\sqrt{s} = 13 TeV

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    The polarizations of prompt and non-prompt J∕ψ and ψ(2S) mesons are measured in proton-proton collisions at √ = 13 TeV, using data samples collected by the CMS experiment in 2017 and 2018, corresponding to a total integrated luminosity of 103.3 fb1^{−1}. Based on the analysis of the dimuon decay angular distributions in the helicity frame, the polar anisotropy, , is measured as a function of the transverse momentum, T_T, of the charmonium states, in the 25–120 and 20–100 GeV ranges for the J∕ψ and ψ(2S), respectively. The non-prompt polarizations agree with predictions based on the hypothesis that, for T ≳ 25 GeV, the non-prompt J∕ψ and ψ(2S) are predominantly produced in two-body B meson decays. The prompt results clearly exclude strong transverse polarizations, even for T_T exceeding 30 times the J∕ψ mass, where tends to an asymptotic value around 0.3. Taken together with previous measurements, by CMS and LHCb at √ = 7 TeV, the prompt polarizations show a significant variation with T_T, at low T_T
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