Large non-adiabatic hole polarons and matrix element effects in the angle-resolved photoemission spectroscopy of dielectric cuprates

It has been made an extention of the conventional theory based on the assumption of the well isolated Zhang-Rice singlet to be a first electron-removal state in dielectric copper oxide. One assumes the photohole has been localised on either small (pseudo)Jahn-Teller polaron or large non-adiabatic polaron enclosed one or four to five $CuO_4$ centers, respectively, with active one-center valent $(^{1}A_{1g}-{}^{1,3}E_{u})$ manifold. In the framework of the cluster model we have performed a model microscopic calculation of the ${\bf k}$-dependence of the matrix element effects and photon polarization effects for the angle-resolved photoemission in dielectric cuprate like $Sr_{2}CuO_{2}Cl_{2}$. We show that effects like the ''remnant Fermi surface'' detected in ARPES experiment for $Ca_{2}CuO_{2}Cl_{2}$ may be, in fact, a reflection of the matrix element effects, not a reflection of the original band-structure Fermi surface, or the strong antiferromagnetic correlations. The measured dispersion-like features in the low-energy part of the ARPES spectra may be a manifestation of the complex momentum-dependent spectral line-shape of the large PJT polaron response, not the dispersion of the well-isolated Zhang-Rice singlet in antiferromagnetic matrix.Comment: 16 pages, TeX, 9 eps figures adde

Large Non-Adiabatic Hole Polarons and Matrix Element Effects in the Angle-Resolved Photoemission Spectroscopy of Dielectric Cuprates

We propose a generalization of the conventional theory based on the assumption of the well-isolated Zhang-Rice 1A1g singlet to be a first electron-removal state in insulating copper oxide. The photohole is assumed to be localized on either small (pseudo) Jahn-Teller (PJT) polaron or large non-adiabatic polaron-enclosed one or four to five CuO4 centers, respectively, with active one-center valent (1A1g-1,3Eu) manifold. In the framework of the cluster model we have performed the model microscopic calculation of the k-dependence of the matrix element effects and photon polarization effects for the angle-resolved photoemission (ARPES) in insulating cuprates like Sr2CuO2Cl2. We show that effects like the "remnant Fermi surface" detected in the ARPES experiment for Ca2CuO2Cl2 may be, in fact, the manifestation of the matrix element effects rather than of the original band-structure Fermi surface or strong antiferromagnetic correlations. The measured dispersion-like features in the low-energy part of the ARPES spectra may be the manifestation of the complex momentum-dependent spectral line shape of the large PJT polaron response, in addition to the dispersion effect for the well-isolated Zhang-Rice singlet in antiferro-magnetic matrix. © 2002 Elsevier Science B.V. All rights reserved.We wish to thank S.-L. Drechsler and R. Hayn for valuable discussions. The research described in this publication was made possible in part by Award No. REC-005 of the US Civilian Research & Development Foundation for the Independent States of the Former Soviet Union (CRDF). The authors acknowledge a partial support from the Russian Ministry of Education, Grant E00-3.4-280, and Russian Foundation for Basic Researches, Grant 01-02-96404

The lightest scalar glueball

Recently performed investigations of meson spectra allow us to determine the resonance structure for the waves $IJ^{PC}=00^{++}$, $10^{++}$, $02^{++}$, $12^{++}$ = $IJ^P= 1/2 0^+$ in the mass region up to 1900 MeV, thus establishing the meson multiplets $1^3P_0q\bar q$ and $2^3P_0q\bar q$. Experimental data demonstrate that there are five scalar/isoscalar states in this mass region. Four of them are $q\bar q$ states, that is, members of the $1^3P_0q\bar q$ and $2^3P_0q\bar q$ nonets, while the fifth state is an extra one not accomodated by $q \bar q$ systematics; it has the properties of the lightest scalar glueball. Analysis of the $00^{++}$-wave performed within the framework of the dispersion relation technique allows us to reconstruct the mixing of a pure gluonium with neighbouring scalar $q \bar q$ states belonging to $1^3P_0q\bar q$ and $2^3P_0q\bar q$ nonets: three scalar mesons share the gluonium state between each other -- those are two comparatively narrow resonances $f_0(1300)$ and $f_0(1500)$ and a broad resonance $f_0(1530^{+90}_{-250})$. The broad state is a descendant of the gluonium, keeping about 40-50% of its component.Comment: 48 pages, LaTeX, 25 PostScript figures, epsfig.sty. Submitted to Russian Journal Uspekhi Fiz. Nauk (Phys-Uspekhi

An Evolutionary Reduction Principle for Mutation Rates at Multiple Loci

A model of mutation rate evolution for multiple loci under arbitrary selection is analyzed. Results are obtained using techniques from Karlin (1982) that overcome the weak selection constraints needed for tractability in prior studies of multilocus event models. A multivariate form of the reduction principle is found: reduction results at individual loci combine topologically to produce a surface of mutation rate alterations that are neutral for a new modifier allele. New mutation rates survive if and only if they fall below this surface - a generalization of the hyperplane found by Zhivotovsky et al. (1994) for a multilocus recombination modifier. Increases in mutation rates at some loci may evolve if compensated for by decreases at other loci. The strength of selection on the modifier scales in proportion to the number of germline cell divisions, and increases with the number of loci affected. Loci that do not make a difference to marginal fitnesses at equilibrium are not subject to the reduction principle, and under fine tuning of mutation rates would be expected to have higher mutation rates than loci in mutation-selection balance. Other results include the nonexistence of 'viability analogous, Hardy-Weinberg' modifier polymorphisms under multiplicative mutation, and the sufficiency of average transmission rates to encapsulate the effect of modifier polymorphisms on the transmission of loci under selection. A conjecture is offered regarding situations, like recombination in the presence of mutation, that exhibit departures from the reduction principle. Constraints for tractability are: tight linkage of all loci, initial fixation at the modifier locus, and mutation distributions comprising transition probabilities of reversible Markov chains.Comment: v3: Final corrections. v2: Revised title, reworked and expanded introductory and discussion sections, added corollaries, new results on modifier polymorphisms, minor corrections. 49 pages, 64 reference

The state and environmental management: general regulatory issues

The authors set the task based on the importance of the role of the state- to analyze the state policy of Russia and several foreign countries in the direction of environmental management. The research focus concerned the classification of the main policy areas of environmental management regulation and the identification of problems related to special state activities in this are

Comparative genome analysis of Pseudogymnoascus spp. reveals primarily clonal evolution with small genome fragments exchanged between lineages

Abstract Background Pseudogymnoascus spp. is a wide group of fungi lineages in the family Pseudorotiaceae including an aggressive pathogen of bats P. destructans. Although several lineages of P. spp. were shown to produce ascospores in culture, the vast majority of P. spp. demonstrates no evidence of sexual reproduction. P. spp. can tolerate a wide range of different temperatures and salinities and can survive even in permafrost layer. Adaptability of P. spp. to different environments is accompanied by extremely variable morphology and physiology. Results We sequenced genotypes of 14 strains of P. spp., 5 of which were extracted from permafrost, 1 from a cryopeg, a layer of unfrozen ground in permafrost, and 8 from temperate surface environments. All sequenced genotypes are haploid. Nucleotide diversity among these genomes is very high, with a typical evolutionary distance at synonymous sites dS ≈ 0.5, suggesting that the last common ancestor of these strains lived >50Mya. The strains extracted from permafrost do not form a separate clade. Instead, each permafrost strain has close relatives from temperate environments. We observed a strictly clonal population structure with no conflicting topologies for ~99% of genome sequences. However, there is a number of short (~100–10,000 nt) genomic segments with the total length of 67.6 Kb which possess phylogenetic patterns strikingly different from the rest of the genome. The most remarkable case is a MAT-locus, which has 2 distinct alleles interspersed along the whole-genome phylogenetic tree. Conclusions Predominantly clonal structure of genome sequences is consistent with the observations that sexual reproduction is rare in P. spp. Small number of regions with noncanonical phylogenies seem to arise due to some recombination events between derived lineages of P. spp., with MAT-locus being transferred on multiple occasions. All sequenced strains have heterothallic configuration of MAT-locus.http://deepblue.lib.umich.edu/bitstream/2027.42/111733/1/12864_2015_Article_1570.pd

Transcriptome‐based phylogeny of endemic Lake Baikal amphipod species flock: fast speciation accompanied by frequent episodes of positive selection

Endemic species flocks inhabiting ancient lakes, oceanic islands and other long‐lived isolated habitats are often interpreted as adaptive radiations. Yet molecular evidence for directional selection during species flocks radiation is scarce. Using partial transcriptomes of 64 species of Lake Baikal (Siberia, Russia) endemic amphipods and two nonendemic outgroups, we report a revised phylogeny of this species flock and analyse evidence for positive selection within the endemic lineages. We confirm two independent invasions of amphipods into Baikal and demonstrate that several morphological features of Baikal amphipods, such as body armour and reduction in appendages and sensory organs, evolved in several lineages in parallel. Radiation of Baikal amphipods has been characterized by short phylogenetic branches and frequent episodes of positive selection which tended to be more frequent in the early phase of the second invasion of amphipods into Baikal when the most intensive diversification occurred. Notably, signatures of positive selection are frequent in genes encoding mitochondrial membrane proteins with electron transfer chain and ATP synthesis functionality. In particular, subunits of both the membrane and substrate‐level ATP synthases show evidence of positive selection in the plankton species Macrohectopus branickii, possibly indicating adaptation to active plankton lifestyle and to survival under conditions of low temperature and high hydrostatic pressures known to affect membranes functioning. Other functional categories represented among genes likely to be under positive selection include Ca‐binding muscle‐related proteins, possibly indicating adaptation to Ca‐deficient low mineralization Baikal waters.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/136009/1/mec13927.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/136009/2/mec13927_am.pd

Сравнительная оценка стандартного эхокардиографического исследования и классификационной модели на основе параметров функциональной геометрии левого желудочка в диагностике систолической дисфункции трансплантированного сердца

Objective. The purpose of this study was to assess the state of left ventricular (LV) systolic dysfunction for an extended period after heart transplantation using the parameters of the functional geometry of the left ventricle. Material and Methods. The study included 31 patients after orthotopic heart transplantation with a follow-up period of up to nine years. We used linear discriminant analysis to build a classification model based on either the standard echocardiographic parameters of LV systolic function or parameters of LV functional geometry indexes aimed at the potential prediction of acute rejection and progression of chronic heart failure. Results. The linear discriminant analysis model based on parameters of LV functional geometry showed a high predictive value to diagnose acute rejection and development of heart failure in heart transplant patients. Conclusion. Linear discriminant analysis classification model based on the LV functional geometry data showed high accuracy in predicting allograft rejection and development of heart failure in heart transplant patients. © 2022 Industrial Laboratory. Materials Diagnostics. All rights reserved.The work was carried out within the framework of state assignments for the Ural State Medical University of Minzdrav of Russia (theme № AAAA-A18-118051590064) and Institute of Immunology and Physiology, Ural Branch of the Russian Academy of Sciences (theme No AAAAA18-118020590031-8). This work was supported by Decree of the Russian Government №211 of March 16, 2013 (agreement 02.A03.21.0006)

Significance of neutrophil flow cytometry in laboratory monitoring in coronary heart disease

The aim of the work is a comparative assessment of quantitative and functional parameters of blood neutrophils in patients with different forms of ischemic heart disease (IHD). In patients with acute myocardial infarction and IHD disease, the number of neutrophils, the content of myeloperoxidase in them by flow cytometry, the level of markers of myocardial damage in immunochemical tests were determined. An increase in the level of neutrophils, including band forms, with a decrease in the level of intracellular myeloperoxidase was established. These changes were more significant in acute myocardial infarction than in IHD. The correlation of the myeloperoxidase level with troponin concentration is shown. The study of peripheral blood neutrophils by flow cytometry with the determination of intracellular myeloperoxidase can be considered as an additional tool for laboratory diagnosis of ischemic heart disease.Цель работы — сравнительная оценка количественных и функциональных параметров нейтрофилов крови, определенных методом проточной цитометрии, у пациентов с разными формами ИБС. У пациентов с острым инфарктом миокарда и хронической ИБС определяли количество нейтрофилов и содержание в них миелопероксидазы методом проточной цитометрии, а также уровень маркеров повреждения миокарда в сыворотке крови. Установлено повышение уровня нейтрофилов, в том числе молодых форм с одновременным снижением уровня внутриклеточной миелопероксидазы. Эти изменения были более выражены при остром инфаркте миокарда, чем при хронической ИБС. Показана корреляционная связь содержания миелопероксидазы с концентрацией тропонина. Исследование нейтрофилов периферической крови методом проточной цитометрии с определением внутриклеточной миелопероксидазы может рассматриваться в качестве дополнительного инструмента лабораторной диагностики ИБС

A Strong Deletion Bias in Nonallelic Gene Conversion

Gene conversion is the unidirectional transfer of genetic information between orthologous (allelic) or paralogous (nonallelic) genomic segments. Though a number of studies have examined nucleotide replacements, little is known about length difference mutations produced by gene conversion. Here, we investigate insertions and deletions produced by nonallelic gene conversion in 338 Drosophila and 10,149 primate paralogs. Using a direct phylogenetic approach, we identify 179 insertions and 614 deletions in Drosophila paralogs, and 132 insertions and 455 deletions in primate paralogs. Thus, nonallelic gene conversion is strongly deletion-biased in both lineages, with almost 3.5 times as many conversion-induced deletions as insertions. In primates, the deletion bias is considerably stronger for long indels and, in both lineages, the per-site rate of gene conversion is orders of magnitudes higher than that of ordinary mutation. Due to this high rate, deletion-biased nonallelic gene conversion plays a key role in genome size evolution, leading to the cooperative shrinkage and eventual disappearance of selectively neutral paralogs