171 research outputs found

    Genetic diversity in wild diploid wheat T. urartu revealed by SSR markers

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    Genetic diversity of 74 T. urartu genotypes was studied using 11 SSR (simple sequence repeats) markers. The number of alleles ranged from 4 to 15, with an average of 8 alleles per primer. The mean values for the expected heterozygosity (He) and polymorphism information content (PIC) over all loci and populations were 0.56 and 0.52, respectively. From a geographic viewpoint the higher diversities were observed in Jordan, followed by Syria and Turkey. Diversity revealed within countries was higher than among them, even in the same regions of the relevant countries. The analysis of molecular variance revealed that most of the genetic variability was accounted for by differences within populations (90%), with less variability among them (10%). The dendrogram generated based on Nei’s dissimilarity matrix revealed three main clusters for which the grouping patterns were not clearly associated with the geographic origins, indicating the gene flow among different countries. Principal coordinate analysis (PCoA) confirmed subgrouping obtained by cluster analysis. In general, genetic distances between geographic regions were low or moderate, which was also supported by low values of pairwise Fst. Our findings can direct the sampling strategies on T. urartu in studied regions to find beneficial alleles. The heterotic groups detected by cluster and PCoA analysis in the present study can serve as effective candidates in crossing programs to broaden the genetic base in T. urartu

    Stereodivergent, Diels-Alder-initiated organocascades employing α,β-unsaturated acylammonium salts: scope, mechanism, and application.

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    Chiral α,β-unsaturated acylammonium salts are novel dienophiles enabling enantioselective Diels-Alder-lactonization (DAL) organocascades leading to cis- and trans-fused, bicyclic γ- and δ-lactones from readily prepared dienes, commodity acid chlorides, and a chiral isothiourea organocatalyst under mild conditions. We describe extensions of stereodivergent DAL organocascades to other racemic dienes bearing pendant secondary and tertiary alcohols, and application to a formal synthesis of (+)-dihydrocompactin is described. A combined experimental and computational investigation of unsaturated acylammonium salt formation and the entire DAL organocascade pathway provide a rationalization of the effect of Brønsted base additives and enabled a controllable, diastereodivergent DAL process leading to a full complement of possible stereoisomeric products. Evaluation of free energy and enthalpy barriers in conjunction with experimentally observed temperature effects revealed that the DAL is a rare case of an entropy-controlled diastereoselective process. NMR analysis of diene alcohol-Brønsted base interactions and computational studies provide a plausible explanation of observed stabilization of exo transition-state structures through hydrogen-bonding effects

    Long-Range Dependence and Sea Level Forecasting

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    This study shows that the Caspian Sea level time series possess long range dependence even after removing linear trends, based on analyses of the Hurst statistic, the sample autocorrelation functions, and the periodogram of the series. Forecasting performance of ARMA, ARIMA, ARFIMA and Trend Line-ARFIMA (TL-ARFIMA) combination models are investigated. The forecast confidence bands and the forecast updating methodology, provided for ARIMA models in the literature, are modified for the ARFIMA models. Sample autocorrelation functions are utilized to estimate the differencing lengths of the ARFIM

    Study of the genetic polymorphism of diploid wheat Triticum boeoticum Boiss. using SSR markers

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    Diploid wheat Triticum boeoticum Boiss. (genome constitution AA) is a promising source of new valu­able alleles for improving cultivated wheat species. Therefore, the evaluation of the intraspecies diversity of T. boeoticum and DNA fingerprinting of accessions of this species are topical tasks. In this paper, the ge­netic diversity of over 60 T. boeoticum accessions was studied using 11 SSR markers. The analysis revealed 83 alleles, 7.5 alleles per locus on the average. The values of expected (HE) and observed (HO) heterozygosity varied within 0.00–0.74 and 0.17–0.89, respectively, the average indices being HO = 0.13 and HE = 0.52. The PIC value for each locus was within 0.17–0.88, 0.49 on the average. Unique alleles were found in all loci studied. Cluster analysis allowed the accessions studied to be combined into five major groups. The distances between the groups varied from 0 to 1, pointing to a high level of genetic differences in the collection under study. On the base of PCoA, five major groups were formed and some correspondence with the dendrogram was detected. Summarizing the data of PCoA and cluster analysis, we noted a weak genetic differentiation in the studied collection of T. boeoticum. A correlation between the genetic distance and geographic origin was revealed only for accessions of diploid wheat T. boeoticum from Iran. The analysis of the T. boeoticum accessions studied showed a wide diversity for SSR loci. The results expand our knowledge and pro­vide additional information on the genetic structure of the collection and on the genetic diversity of T. boeoti­cum accessions studied

    The Salts of Nitronic acid as CO2-Corrosion Inhibitors

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    The salts of nitronic acids were obtained by nitration of higher olefins, both normal and isomeric structure in the presence of aqueous alkali. The resulting salts (Na+, K+, NH4+), were tested in CO2 -media as a corrosion inhibitor. The results showed that, the protective effect of the linear nitronated olefins increases by increasing the number of carbon atoms. This is due to the fact that because of  the branched structure of the compounds, it is much more difficult to form a dense protective layer on the metal surface. 20% solutions of nitronated ethanolamine in isopropyl alcohol was synthesized and tested as corrosion inhibitor in carbon dioxide environments. The results showed that diethanolamine nitron based on a mixture of normal olefins C16-C18 at a concentration of 50 ppm has a high protective effect of  99.69%

    CONSERVATIVE FLUIDS AND LUBRICANTS BASED ON TURBINE OIL, NITRO, AMIDO AND PARAFFIN WAX

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    To create conservation fluids and lubricants based on the oil acids and polyethylene polyamine (PEPA) synthesized amidoamines, and based on α-olefins (C12, C14 and C16-C18) and the nitric acids-nitro compounds. Using of amido, nitro and solid n-paraffins in the turbine oil T-30 (Standard 32-74) formulated lubricants and conservation fluid which are tested under different conditions. It is shown that in comparison with the preservative fluid, the preservative lubrication more effective

    Adaptive potential of durum wheat (Triticum durum Desf.) varieties of Azerbaijan

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    Background. Studies into the adaptability of the genetic diversity of cultivated plants and their wild relatives to various environments are induced by global climate change. Introduction of adaptive wheat cultivars resistant to environmental stressors is the basis for stable harvests. This article presents the results of a research into the adaptive value of indigenous durum wheat varieties and improved cultivars released in different years in Azerbaijan.Materials and methods. The experiments were carried out in the foothills of Mountainous Shirvan under unsecured non-irrigation at Gobustan Experiment Station of the Research Institute of Crop Husbandry. In 2012–2014, contrasting in weather conditions, levels and structure of yield were analyzed. VIR’s guidelines were used to study 42 durum wheat varie ties, including 10 landraces. The years of study differed sharply in rainfall. Selyaninov’s hydrothermal coefficient was used to assess the conditions of growing seasons.Results. Mostly modern cultivars of the semi-intensive type were distinguished for a set of agrobiological traits. Adaptability coefficients (0.81–1.23) showed that the response of the studied varieties to unfavorable conditions was highly expressed. Indigenous landraces ‘Ag bughda’ and ‘Bozak’, old breeding varieties ‘Arandani’, ‘Ag bughda 13’, ‘Kahraba’ and ‘Mirbashir 50’, and new cultivars ‘Karagilchig 2’ and ‘Barakatli 95’ had the highest adaptability coefficients. The first of them demonstrated stable yield, and the latter two were also resistant to stressors.Conclusion. Durum wheat yields under the conditions of moderately continental climate in Mountainous Shirvan depended on the number and weight of grains per ear. The varieties identified for the best adaptability are recommended to be included in crosses to develop new plastic cultivars of durum wheat

    Analysis of Structure Destroyed Metal after Diffusion Heat Treatment

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    It was accomplished research of the structure steel which carbonitriding and subsequent heat treatment was exposed for its cause's destruction to discover. For measure quality field of metal were used methods optical, appearing electronic microscopy and X-ray diffraction. Therefore one of the principal problems were research phase composition, grain and dislocation structure of a metal the gear teeth. Mechanism of rising hear cracks in the gear teeth on different stages her making and their trajectories of evolution were determined

    2-[2-(4-Methoxyphenyl)-4,5-diphenyl-1 H

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    In the title compound, C(24)H(22)N(2)O(2), the central imidazole ring makes dihedral angles of 49.45 (8), 88.94 (9) and 19.43 (8)° with the benzene ring and the two phenyl rings, respectively. The dihedral angle between the phenyl rings is 77.86 (9)°, and they form dihedral angles of 49.06 (9) and 67.31 (8)° with the benzene ring. In the crystal, mol­ecules are linked by O—H⋯N hydrogen bonds, forming chains along the b axis. These chains are connected by C—H⋯O hydrogen bonds, forming a two-dimensional network parallel to (100). In addition, C—H⋯π inter­actions are also observed. The terminal C and O atoms of the ethanol group are disordered over two sets of sites with an occupancy ratio of 0.801 (5):0.199 (5)
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