377 research outputs found

    Evolution of the S-Genomes in Triticum-Aegilops Alliance: Evidences From Chromosome Analysis

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    Five diploid Aegilops species of the Sitopsis section: Ae. speltoides, Ae. longissima, Ae. sharonensis, Ae. searsii, and Ae. bicornis, two tetraploid species Ae. peregrina (= Ae. variabilis) and Ae. kotschyi (Aegilops section) and hexaploid Ae. vavilovii (Vertebrata section) carry the S-genomes. The B- and G-genomes of polyploid wheat are also the derivatives of the S-genome. Evolution of the S-genome species was studied using Giemsa C-banding and fluorescence in situ hybridization (FISH) with DNA probes representing 5S (pTa794) and 18S-5.8S-26S (pTa71) rDNAs as well as nine tandem repeats: pSc119.2, pAesp_SAT86, Spelt-1, Spelt-52, pAs1, pTa-535, and pTa-s53. To correlate the C-banding and FISH patterns we used the microsatellites (CTT)10 and (GTT)9, which are major components of the C-banding positive heterochromatin in wheat. According to the results obtained, diploid species split into two groups corresponding to Emarginata and Truncata sub-sections, which differ in the C-banding patterns, distribution of rDNA and other repeats. The B- and G-genomes of polyploid wheat are most closely related to the S-genome of Ae. speltoides. The genomes of allopolyploid wheat have been evolved as a result of different species-specific chromosome translocations, sequence amplification, elimination and re-patterning of repetitive DNA sequences. These events occurred independently in different wheat species and in Ae. speltoides. The 5S rDNA locus of chromosome 1S was probably lost in ancient Ae. speltoides prior to formation of Timopheevii wheat, but after the emergence of ancient emmer. Evolution of Emarginata species was associated with an increase of C-banding and (CTT)10-positive heterochromatin, amplification of Spelt-52, re-pattering of the pAesp_SAT86, and a gradual decrease in the amount of the D-genome-specific repeats pAs1, pTa-535, and pTa-s53. The emergence of Ae. peregrina and Ae. kotschyi did not lead to significant changes of the S*-genomes. However, partial elimination of 45S rDNA repeats from 5S* and 6S* chromosomes and alterations of C-banding and FISH-patterns have been detected. Similarity of the Sv-genome of Ae. vavilovii with the Ss genome of diploid Ae. searsii confirmed the origin of this hexaploid. A model of the S-genome evolution is suggested

    Cooperation of China and Russia in the framework of the Asian Super Grid : political and legal aspects

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    The authors present data on the current situation regarding the organization of electricity exports and analyze the potential of the Russian Far East in electricity production in the context of the financial and investment interaction between China and Russia. The research showed that by building up its own export potential in the electricity power industry will allow Russia to strengthen the existing electric power complex of the Russian regions bordering with China making qualitative changes in the structure of the trade balance between these countries with respect to energy resources.peer-reviewe

    Economization of information and scientific data : a common approach

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    The authors present a study on the economization of information and scientific data in the current information society that creates grounds for the rapid development of the economy of knowledge. The study reveals that both information and scientific data became the object of attention of economists who tried to explain the behavior of scientists and groups of scientists (research communities) from a standpoint of not only ‘disinterestedness’ in scientific research, but also in the context of striving to optimize their costs and earns.The reported study was funded by RFBR according to the research project № 18-29-15030 mk on the theme “Scientific information in the orbit of the content, forms and problems of intellectual property rights protection (comparison with regard to the experience of BRICS countries)” (Grantee – Dr. of Sciences, Prof. Ksenia M. Belikova, Peoples’ Friendship University of Russia (RUDN University), www.rudn.ru)peer-reviewe

    Enhanced two-photon absorption of organic chromophores: theoretical and experimental assessments

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    C. Katan present address: CNRS UMR6082 FOTON, INSA de Rennes, 20 avenue des Buttes de Coësmes, CS 70839, 35708 RENNES cedex 7, FranceInternational audienceFunctional organic materials with enhanced two-photon absorption (TPA) lead to new technologies in the fields of chemistry, biology, and photonics. In this article we review experimental and theoretical methodologies allowing detailed investigation and analysis of TPA properties of organic chromophores. This includes femtosecond two-photon excited fluorescence (TPEF) experimental setups and quantum-chemical methodologies based on time-dependent density functional theory (TD-DFT). We thoroughly analyze physical phenomena and trends leading to large TPA responses of a few series of model chromophores focusing on the effects of symmetric and asymmetric donor/acceptor substitution and branching

    Tuning Photophysics And Nonlinear Absorption Of Bipyridyl Platinum(ii) Bisstilbenylacetylide Complexes By Auxiliary Substituents

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    The photophysics of six bipyridyl platinum(II) bisstilbenylacetylide complexes with different auxiliary substituents are reported. These photophysical properties have been investigated in detail by UV-vis, photoluminescence (both at room temperature and at 77 K) and transient absorption (nanosecond and femtosecond) spectroscopies, as well as by linear response time-dependent density functional theory (TD-DFT) calculations. The photophysics of the complexes are found to be dominated by the singlet and triplet pi,pi* transitions localized at the stilbenylacetylide ligands with strong admixture of the metal-to-ligand (MLCT) and ligand-to-ligand (LLCT) charge-transfer characters. The interplay between the pi,pi* and MLCT/LLCT states depends on the electron-withdrawing or -donating properties of the substituents on the stilbenylacetylide ligands. All complexes exhibit remarkable reverse saturable absorption (RSA) at 532 nm for nanosecond laser pulses, with the complex that contains the NPh2 substituent giving the strongest RSA and the complex with NO2 substituent showing the weakest RSA

    Modalization of Speech Actions as the Basis of the Metaphoric Transfer (on the Example of German Economic Discourse)

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    The question of the nature of speech modalization has been repeatedly considered in linguistics from various positions, which is partially reflected in the text of the article. The authors of the publication propose to look at the points of intersection of the process of metaphorization of statements within the framework of one type of discourse with the expression of the author's attitude to and/or assessment of its content. To substantiate the validity of this approach, the authors refer to the methodology of logical analysis of language, the theory of intersubjectivity and the theory of evaluativity, linking cognitive methods of analyzing the process of metaphorization with a broad understanding of the category of modality. This formulation of the problem fits into the modern scientific paradigm of interdisciplinarity and the actualization of interdisciplinary relations, which reflects the relevance of the proposed text. The scientific novelty of the topic is an attempt to determine the correlation of the category of modality in its axiological and ideological aspects with metaphorization as a means of actualizing evaluativity in economic discourse. Commonly, denoting phenomena, processes or results is not limited to their nomination, but the producer of the utterance gives them a modal assessment. The empirical material containing fragments of texts of the German-language mass media on economic topics reflects the validity of the proposed interpretation of the issue, shows the potential relationship of phenomena in the intersection of various connotative meanings of a cognitive metaphor, potentially serving to express the attitude to the proposition of an utterance at the level of intersubjective assessments that create a modal frame of the text. The given examples clearly demonstrate that cognitive metaphors in various forms of their implementation could serve to express ideological modality from the standpoint of intersubjectivity, since the producer of the text relies on the reflection of a fragment of reality in the communicative and cognitive activity of subjects of the national-cultural community of people. The article recognizes a certain ambiguity of the proposed interpretation of the category of modality, which is considered in the traditional grammar as an expression of possibility, ought and desirability, or as a confidence, doubt and assertion that the action is carried out at different time levels using phrases with modal verbs, modal words or adverbs, particles, etc. Thus, the article can be considered as an indirect invitation to a discussion on the issue

    Use of H. vulgare EST Markers, GISH and C-banding to Study Bread Wheat – H. marinum subsp. gussoneanum (2n = 28) Introgression Lines

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    Wild barley, Hordeum marinum subsp. gussoneanum (2n = 28) is a valuable source of genes that determine resistance to abiotic stresses. These resistance traits might be transferred to wheat due to the crossability of wild barley with bread wheat. The availability of reliable and rapid methods for the identification of H. marinum subsp. gussoneanum chromatin in a wheat background would facilitate the development of introgression wheat genotypes. For this purpose, we evaluated the applicability of eighty-seven H. vulgare EST markers for studying bread wheat – H. marinum subsp. gussoneanum substitution and addition lines. Of all of the markers studied, forty-three (49%) were amplified in H. marinum ssp. gussoneanum and wheat introgression lines. The identification of wild barley chromosomes using EST markers confirmed the GISH and C-banding data. Thus, it was established that the H. vulgare EST markers can be successfully used to identify the chromosomes of the H. marinum subsp. gussoneanum in introgression lines of wheat

    Simultaneous control of emission localization and two-photon absorption efficiency in dissymmetrical chromophores

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    C. K's secondary address for this work: CNRS UMR6082 FOTON, INSA de Rennes, 20 avenue des Buttes de Coësmes, CS 70839, 35708 RENNES cedex 7, FranceWe thank E. Leroux for technical assistance in the synthesis, S. Soualmi in electrochemical mesaurements and M. H. V. Werts for help in the TPEF measurements.International audienceThe aim of the present work is to demonstrate that combined spatial tuning of fluorescence and two-photon absorption (TPA) properties of multipolar chromophores can be achieved by introduction of slight electronic chemical dissymmetry. In that perspective, two model series of structurally related chromophores have been designed and investigated. One is based on rod-like quadrupolar chromophores bearing either two identical or different electron-donating (D) end groups and the other on three-branched octupolar chromophores built from a trigonal donating moiety bearing identical or different acceptor (A) peripheral groups. The influence of the electronic dissymmetry is investigated by combined experimental and theoretical studies of the linear and nonlinear optical properties of dissymmetrical chromophores compared to their symmetrical counterparts. In both types of systems (i.e., quadrupoles and octupoles), experiments and theory reveal that excitation is essentially delocalized and that excitation involves synchronized charge redistribution (i.e., concerted intramolecular charge transfer) between the different D and A moieties within the multipolar structure. In contrast, the emission stems only from a particular dipolar subunit bearing the strongest D or A moiety due to fast excitation localization after excitation, prior to emission. Hence, control of emission characteristics (polarization and emission spectrum), can be achieved, in addition to localization, by controlled introduction of electronic dissymmetry (i.e., replacement of one of the D or A end-groups by a slightly stronger D′ or A′ unit). Interestingly, slight dissymmetrical functionalization of both quadrupolar and octupolar compounds does not lead to significant loss in TPA responses and can even be beneficial due to the spectral broadening and peak position tuning that it allows. This study thus reveals an original molecular engineering route allowing TPA enhancement in multipolar structures, due to concerted core-to-periphery or periphery-to-core intramolecular charge redistribution upon excitation, while providing for control of emission localization. Such a route could be extended to more intricate (dendritic) and multipolar (3D) systems

    Alien introgressions and chromosomal rearrangements do not affect the activity of gliadin-coding genes in hybrid lines of Triticum aestivum L. × Aegilops columnaris Zhuk

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    Using chromosome C-banding and electrophoresis of grain storage proteins, gliadins, 17 Triticum aestivumAegilops columnaris lines with substitutions of chromosomes of homoeologous groups 1 and 6 were examined. Based on their high polymorphism, gliadins were used to identify alien genetic material. For all of the lines examined, electrophoretic analysis of gliadin spectra confirmed substitution of wheat chromosomes 6A, 6D or 1D for the homoeologous Aegilops chromosomes of genomes Uс or Xс. The substitution manifested in the disappearance of the products of gliadin-coding genes on chromosomes 6A, 6D or 1D with the simultaneous appearance of the products of genes localized on alien chromosomes of genomes Uс or Xс. Thus, Aegilops chromosomes were shown to be functionally active in the alien wheat genome. The absence of alien genes expression in the lines carrying a long arm deletion in chromosome 6Xc suggested that the gliadin-coding locus moved from the short chromosome arm (its characteristic position in all known wheat species) to the long one. This is probably associated with a large species-specific pericentric inversion. In spite of losing a part of its long arm and combination with a non-homologous chromosome of a different genome (4BL), chromosome 1D was fully functioning. For Aegilops, the block type of gliadin components inheritance was shown, indicating similarity in the structural organization of gliadin-coding loci in these genera. Based on determining genetic control of various polypeptides in the electrophoretic aegilops spectrum, markers to identify Ae. columnaris chromosomes 1Xс, 6Xс and 6Uс were constructed

    Wheat Landrace Genome Diversity

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    Understanding the genomic complexity of bread wheat (Triticum aestivum L.) is a cornerstone in the quest to unravel the processes of domestication and the following adaptation of domesticated wheat to a wide variety of environments across the globe. Additionally, it is of importance for future improvement of the crop, particularly in the light of climate change. Focussing on the adaptation after domestication, a nested association mapping (NAM) panel of 60 segregating bi-parental populations were developed mainly involving landrace accessions from the core set of the Watkins hexaploid wheat collection optimized for genetic diversity (WINGEN et al. 2014). A modern spring elite variety, ’Paragon’, was used as common reference parent. Genetic maps were constructed following identical rules to make them comparable. In total, 1,611 linkage groups were identified, based on recombination from an estimated 126,300 crossover events over the whole NAM panel. A consensus map, named landrace consensus map (LRC) was constructed and contained 2,498 genetic loci. These newly developed genetics tools were used to investigate the rules underlying genome fluidity or rigidity, e.g. by comparing at marker distances and marker orders. In general, marker order was highly correlated, which provides support for strong synteny between bread wheat accessions. However, many exceptional cases of incongruent linkage groups and increased marker distances were also found. Segregation distortion was detected for many markers, sometimes as hot-spots present in different populations. Furthermore, evidence for translocations in at least 36 of the maps was found. These translocations fell, in general, into many different translocation classes, but a few translocation classes were found in several accessions, the most frequent one being the well known T5B:7B translocation. Loci involved in recombination rate, which is an interesting trait for plant breeding, were identified by QTL analyses using the crossover counts as a trait. In total, 114 significant QTL were detected, nearly half of them with increasing effect from the non-reference parents
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