142 research outputs found

    'Russian bureaucratic ruling elite': towards a social portrait of Russia's higher bureaucracy during the first quarter of the 19th century

    Full text link
    Der vorliegende Beitrag analysiert anhand der Personalakten der Beamten (formuliarnye spisky) die Herrschaftsstruktur im zaristischen Rußland. Die Ergebnisse revidieren ein Stereotyp der sowjetischen Geschichtsschreibung: über ein Drittel der bürokratischen Eliten besaßen keine Leibeigenen. Ein kontinuierliches Wachstum dieser Gruppe läßt sich vor allem für die zentrale Verwaltung des Landes feststellen. Dieser Befund widerlegt die These der (marxistischen) Geschichtswissenschaft, daß die reale Macht in Rußland in den Händen des feudalen Landadels gelegen hat. (pmb)'An attempt is made to study the social structure of Russia's bureaucratic ruling elite during the first quarter of the 19th century. The work is done on the basis of a mass statistic source: service records of bureaucracy (formuliarnye spisky). The results of the research undermine common stereotypes in Soviet historiography. Among the higher bureaucratic elites one third owned no serfs whatsoever. A constant growth of this group was observed, especially in the central bureaucracy. Thus, a close analysis of the data disproves the widely-held belief that real power and authority in Russia was connected with the landed gentry.' (author's abstract

    The selection pressure on the neuraminidase gene of influenza viruses isolated in Ukraine from 2009 to 2015

    Get PDF
    A broad range of naturally occurring antigenic variants of the influenza virus is caused by its rapid evolutionary variability. The survival of viable influenza virus variants occurs through natural selection. The treatment of influenza infection with modern antiviral drugs – neuraminidase (NA) inhibitors – leads to the occurrence of mutations in the NA gene, which thereby result in the emergence of virus resistance to these drugs. The goal of this study was to determine the selection pressure on the NA protein of influenza viruses isolated in Ukraine from 2009 to 2015. The main method for assessing the selection pressure on proteins is to quantify the ratio of substitution rates at nonsynonymous (dN) and synonymous (dS) sites. With the help of this method, we showed that only a few codons in the NA gene were under positive selection resulting in mutations at the following sites: for influenza A viruses of the A(H1N1)pdm09 subtype – site 40, for viruses of the A(H3N2) subtype – sites 93 and 402, for Influenza B viruses of the B/Yamagata lineage – sites 74, 99, and 268, and for the viruses of the B/Victoria lineage – sites 358, 288, and 455. These sites are not associated with the NA active site, transmembrane domain, or the antigenic sites of this protein. We concluded that NA inhibitors are not a significant factor in the process of selection of the influenza viruses in Ukraine because the sites associated with the resistance of influenza viruses to NA inhibitors were not affected by positive selection. This finding could be explained by the limited use of NA inhibitors for the treatment of influenza infections in Ukraine. A broad range of naturally occurring antigenic variants of the influenza virus is caused by its rapid evolutionary variability. The survival of viable influenza virus variants occurs through natural selection. The treatment of influenza infection with modern antiviral drugs – neuraminidase (NA) inhibitors – leads to the occurrence of mutations in the NA gene, which thereby result in the emergence of virus resistance to these drugs. The goal of this study was to determine the selection pressure on the NA protein of influenza viruses isolated in Ukraine from 2009 to 2015. The main method for assessing the selection pressure on proteins is to quantify the ratio of substitution rates at nonsynonymous (dN) and synonymous (dS) sites. With the help of this method, we showed that only a few codons in the NA gene were under positive selection resulting in mutations at the following sites: for influenza A viruses of the A(H1N1)pdm09 subtype – site 40, for viruses of the A(H3N2) subtype – sites 93 and 402, for Influenza B viruses of the B/Yamagata lineage – sites 74, 99, and 268, and for the viruses of the B/Victoria lineage – sites 358, 288, and 455. These sites are not associated with the NA active site, transmembrane domain, or the antigenic sites of this protein. We concluded that NA inhibitors are not a significant factor in the process of selection of the influenza viruses in Ukraine because the sites associated with the resistance of influenza viruses to NA inhibitors were not affected by positive selection. This finding could be explained by the limited use of NA inhibitors for the treatment of influenza infections in Ukraine.

    Coherent control of nuclear spin isomers of molecules: The role of molecular motion

    Get PDF
    Molecular center-of-mass motion is taken into account in the theory of coherent control of nuclear spin isomers of molecules. It is shown that infrared radiation resonant to the molecular rovibrational transition can substantially enrich nuclear spin isomers and speed up their conversion rate.Comment: REVTEX, 13 pages + 3 eps figure

    Influence of allelic polymorphism in the 3’ untranslated region of the <i>StTCP23</i> gene on the tolerance of potato cultivars to the potato spindle tuber viroid

    Get PDF
    Background. It is known that the pathological phenotype of potato plants can be mediated by complementary interactions between the genomic RNA of PSTVd and mRNA of some regulatory genes, which consequently lead to RNA interference, the synthesis of small interfering RNAs (vd-sRNA PSTVd), and impaired morphogenesis. At the same time, symptoms caused by the viroid may vary in different potato cultivars. Here we predict the interactions between the 3’ UTRs of various alleles of the StTCP23 transcription factor gene and the complementary regions in PSTVd genomic RNA.Materials and methods. We selected eight commercial potato cultivars with different symptoms of viroid infection and disease. For each cultivar, six clones of each cDNA amplicon of StTCP23 with a 3’ UTR were identified, and the allelic compositions of the target regions within their 3’ UTRs were characterized.Results. In total, 11 types of alleles of the 3’ UTR StTCP23 segment complementary to the vd-sRNA PSTVd were identified. Cultivars with the A allele (‘Gala’, ‘Colomba’, ‘Favorit’, and ‘Fioletovy’) identical to the reference genome or a high dose of the C allele with a deletion of four nucleotides (cv. ‘Impala’) were characterized by high susceptibility already at the primary (firstyear) infection with the PSTVd. Cvs. ‘Krepysh’, ‘Labadia’ and ‘Riviera’, classified as tolerant during primary inoculation, on the contrary, were characterized by the absence of the A allele and the presence of cultivar-specific mutant alleles.Conclusion. A high degree of polymorphism in the target site (3’ UTR region) of StTCP23 indicates a possible selection pressure on this locus. It can be assumed that cultivars with shorter alleles, which have fewer bases complementary to vd-sRNA in hypothetical duplexes and therefore less likely to induce target gene silencing, are more tolerant to the PSTVd upon primary viroid infection

    Controlling thickness variation during pneumothermal forming in the superplastic regime

    Full text link
    Results are presented from the modeling of different methods of controlling thickness fluctuations in superplastic pneumothermal forming. Recommendations are given on the use of each method and a part made of titanium alloy VT-20 is used as an example to show the thickness distribution over the part for each method. © 2013 Springer Science+Business Media New York

    Transmission of potato spindle tuber viroid between <i>Phytophthora infestans</i> and host plants

    Get PDF
    Potato spindle tuber viroid (PSTVd) is a naked, circular, single-stranded RNA (356–363 nucleotides in length) which lacks any protein-coding sequences. It is an economically important pathogen and is classified as a high-risk plant quarantine disease. Moreover, it is known that PSTVd is mechanically transmitted by vegetative plant propagation through infected pollen, and by aphids. The aim of this study is to determine the possibility of viroid transmission by potato pathogen Phytophthora infestans (Mont.) de Bary. PSTVd-infected (strain VP87) potato cultivars Gala, Colomba, and Riviera were inoculated with P. infestans isolate PiVZR18, and in 7 days, after the appearance of symptoms, re-isolation of P. infestans on rye agar was conducted. RT-PCR diagnostics of PSTVd in a mixture of mycelia and sporangia were positive after 14 days of cultivation on rye agar. The PSTVd-infected P. infestans isolate PiVZR18v+ was used to inoculate the healthy, viroid-free plants of potato cv. Gala and tomato cv. Zagadka. After 60 days, an amplification fragment of PSTVd was detected in the tissues of one plant of tomato cv. Zagadka by RT-PCR with the primer set P3/P4, indicating successful transmission of PSTVd by P. infestans isolate PiVZR18v+. This result was confirmed by sequencing of the RT-PCR amplicon with primers P3/P4. The partial sequence of this amplicon was identical (99.5 %) to PSTVd strain VP87. RT-PCR showed the possibility of viroid stability in a pure culture of P. infestans isolate PiVZR18v+ after three consecutive passages on rye agar. PSTVd was not detected after the eighth passage on rye agar in P. infestans subculture. These results are initial evidence of potato viroid PSTVd being bidirectionally transferred between P. infestans and host plants

    Potato mosaic viruses which infect plants of tuber-bearing Solanum spp. growing in the VIR field gene bank

    Get PDF
    Potato crop is particularly affected by virus diseases, and potato virus Y (PVY) currently considered the most important pathogen distributed worldwide as a diversity of strains. Wild and cultivated tuber-bearing species of the genus Solanum L., stored in the VIR collection, are used as the initial material in creation domestic potato varieties (Solanum tuberosum L.) resistant to virus diseases. The preservation and rational utilization of the potato collection is based on regular phytosanitary monitoring, including quarantine objects, foremost PSTVd (potato spindle tuber viroid). The aim of the work is to examine plants of tuber-bearing Solanum species in the field gene bank of VIR for the presence of PSTVd and PVX (potato virus X), PVS (potato virus S), PVM (potato virus M) and PVY, which are the most common viruses on potatoes in the North-West District of Russia. We examined clonal plants of 137 genotypes representing 31 species of the section Petota of the genus Solanum L. A diagnostic was carried out using ELISA, RT-PCR and indicator plants. No PSTVd was found in the studied plants, but a plural infestation by mosaic viruses was detected, more than half of the tested clones are infected with two or more viruses. In the studied samples, only 17 genotypes (12 %) are not infected by PVX, PVS, PVM and PVY according to the ELISA test. There are statistically significant differences in the virus infestation of Solanum species with different origins, according to Pearson’s chi-squared test. Among the studied genotypes of wild relatives of potatoes, the proportion of those affected by PVY was significantly higher in the South American than in the North American species (χ2 = 4.56, p = 0.03); the proportion of genotypes affected by PVХ was significantly higher in the North American species (χ2 = 8.81, p = 0.003), the critical value was χ2 = 3.841. PVY strains were identified by multiplex RT-PCR in 37 genotypes of Solanum spp. We found that 27 genotypes are infected by a common PVYO strain, two genotypes are infected by PVYNW (A) and PVYNW (B) strains, respectively, seven genotypes are infected by a mixture of PVYO +PVYNW (A) strains, and one is infected by a mixture of PVYO +PVYNTN-NW (SYRI)+SYRIII strains. The recombinant strains of PVY are detected in the North-West District of Russia for the first time. Coherency of the results of PVY strains detection by various (immunological, molecular and biological) methods is discussed

    Expression of the transcription factor encoding gene <i>StTCP23</i> in potato plants infected with the tuber spindle viroid

    Get PDF
    Background The potato spindle tuber viroid (PSTVd) is the smallest of all known potato pathogens. PSTVd is a circular, single-stranded RNA molecule that does not code for proteins. Symptoms caused by PSTVd lead to a significant reduction in tuber yield or death of the plant. PSTVd infection triggers the silencing of host-plant genes and induces disease symptoms in the plant via vd-sRNA. The StTCP23 potato gene which encodes a transcription factor is one of the targets of PSTVd. The aim of the study was to assess the effect of inoculation of potato plants of cv. ‘Colomba’ with the PSTVd viroid NicTr-3 strain on the StTCP23 expression in infected plants.Materials and methods. Potato plants of cv. ‘Colomba’ were inoculated with leaf sap of the tomato cv. ‘Rutgers’ in which the PSTVd viroid NicTr-3 strain was propagated. RT-PCR with specific primers was used to confirm the infection of potato plants with the viroid. Diversity of RNA molecules in the PSTVd population was revealed using RT, cloning, and sequencing of the viroid. The expression of the StTCP23 gene in infected potato plants was assessed by quantitative PCR with the ef1α gene as a reference.Results. Symptoms of infecting ‘Colomba’ plants with the PSTVd viroid strain NicTr-3 were not detected, while the presence of the viroid in potato leaves was confirmed by molecular methods. Ten mutations were found in individual variants of the PSTVd strain NicTr-3, responsible for reducing the viroid’s aggressiveness. An increase in the expression of StTCP23 was shown at 3 time points in ‘Colomba’ plants inoculated with the NicTr-3 strain compared to the control.Conclusion. The mechanism of interaction between PSTVd and the StTCP23 gene in an infected potato plant is not universal and depends both on the potato genotype and viroid strain. Additional studies are required to prove the existence of specific interaction mechanisms between the host-plant and viroid strain genotypes

    Quarantine nematode species and pathotypes potentially dangerous for domestic potato production: populations diversity and the genetics of potato resistance

    Get PDF
    The review considers quarantine species and nematode pathotypes potentially dangerous for domestic potato production. Potatoes are affected by more than 30 types of parasitic nematodes, but the review focuses on the most harmful representatives of genera that cause great damage to potato production: Globodera, Ditylenchus, Nacob bus and Meloidogyne. Phytopathological and molecular methods of identification of species and pathotypes and the main achievements in studying the population variability of parasitic potato nematodes were analyzed. It was shown that due to the peculiarities of the life cycle of nematodes and lability of their genomes, the genetic variability of these organisms is very high, which creates a threat of forming new pathogenic genotypes of the parasites. The information about the intra- and interpopulation variability of nematodes is important for studying the ways of introduction and distribution of separate species, as well as for searching for the correlations of molecular markers with the pathotype. Phylogenetic studies based on modern data on genetic variability of populations have allowed to reveal species complexes in Globodera pallida (Stone) Behrens and Nacobbus aberrans (Thorne) Thorne &amp; Allen (sensu lato), including cryptic species. The main components of successful protection preventing a wide distribution of parasitic nematodes are quarantine measures, agricultural techniques, biological methods of protection and cultivation of resistant cultivars. Special attention in the review is paid to the breeding of potato cultivars with durable resistance to various nematode pathotypes, because the cultivation of such varieties is the most ecologically safe and economically advantageous way to prevent epiphytoties. Currently, significant progress has been made in the genetic protection of potato cultivars, especially against cyst-forming nematodes. The review provides data on sources of potato resistance to parasitic nematodes identified in collections of wild and cultivated species. Data on identified R-gens and QTL of resistance that have been introduced into breeding varieties using different methods and approaches are analyzed. The literature data on the study of structural and functional organization of genes for resistance to potato cyst nematodes are given. The results of molecular research on revealing the polymorphisms of loci involved in the control of resistance to cyst and gall nematodes, the development of molecular markers of certain genes and their use in marker-assisted selection for developing of new resistant cultivars, including those with group resistance, are considered

    Resistance of old winter bread wheat landraces to tan spot

    Get PDF
    Background. The most effective and environmentally safe way to combat wheat diseases is to produce cultivars resistant to their pathogens. For this purpose, old landraces are often used as genetically diverse sources of traits important for breeding. In the process of wheat breeding for resistance to tan spot caused by the fungus Pyrenophora tritici-repentis (Died.) Drechs. (abbr. Ptr), selection is carried out against the dominant allele of Tsn1, the gene of sensitivity to the toxin Ptr ToxA, which induces necrosis and represents the main pathogenicity factor of Ptr controlled by the ToxA gene. The aim of the study was to characterize a set of bread wheat (Triticum aestivum L.) accessions from the VIR collection for resistance to various Ptr populations, genotype these accessions using Xfcp623 – a DNA marker of the Tsn1 gene, and identify sources of tan spot resistance.Materials and methods. Sixty-seven accessions of winter bread wheat landraces were studied. Seedling resistance to two Ptr populations was assessed using a 5-point scale adopted at VIZR. The allelic state of Tsn1 was identified by PCR.Results. Dominant alleles of Tsn1 were found for 55% of the studied accessions. Seventeen accessions were resistant or moderately resistant to two Ptr populations and an isolate from Krasnodar Territory previously used for their characterization. Nine of them had the tsn1tsn1 genotype, and 8 had Tsn1Tsn1. The accessions mainly belonged to three agroecological groups proposed by N. I. Vavilov: “steppe winter bread wheat (Banatka wheats)”, “North European forest awnless bread wheats (Sandomirka wheats)”, and “Caucasian mountain winter bread wheat”.Conclusion. The identified 17 accessions resistant to Ptr are potential breeding sources of resistance. In the studied set of accessions, no significant relationship was found between the allelic state of the Tsn1 gene in the accession and its response to the infection with pathogen populations, including isolates with the ToxA gene
    corecore