1,405 research outputs found

    DETERMINATION OF A CRITICAL ZONE OF ETHYLENE GLYCOL SOLUTION OF CRYSTAL FORMATION IN A WIDE SPECTRUM OF FREEZE-THAWING RATES

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     «Візуальним» методом визначено залежність ступеня помутніння середовища від концентрації етиленгліколю (0¸70 % [v/v]) і швидкості заморожування-відтавання (10¸16×103 0С/хв). Отримано регресійне рівняння, яке спрощує встановлення мінімальної концентрації вітрифікуючого розчину кріопротектору, що містить етиленгліколь, яка забезпечує прозорість середовища при заданій швидкості теплообміну. Встановлено мінімальну концентрацію вітрифікуючого  розчину кріопротектору для  кріоконсервування  ембріонів  ссавців  (53 %  [v/v]), що  містить  етиленгліколь  і  сахарозу  (у співвідношенні 2:1), яка забезпечує  прозорість середовища при швидкості 6´103 0С/хв. «Визуальным» методом установлена зависимость степени помутнения среды от концентрации этиленгликоля (0¸70% [v/v]) и скорости замораживания-оттаивания (10¸16×103 0С/мин). Получено регрессионное уравнение, которое упрощает определение минимальной концентрации витрифицирующего раствора криопротектора, содержащего этиленгликоль и обеспечивающее прозрачность среды при заданной скорости теплообмена.Установлена минимальная концентрация витрифицирующего раствора криопротектора для криоконсервирования эмбрионов млекопитающих (53 % [v/v]), состоящая из  этиленгликоля и сахарозы (в соотношении 2 : 1), которая обеспечивает прозрачность среды при скорости 6´103 0С/мин.The «visual» method established dependence of extent of turbidity of the environment on concentration of ethylene glycol (0¸70% [v/v]) and of freeze-thawing rates (10¸16×103 0С/min). The regression equation which simplifies determination of the minimum concentration of vitrifications solution of the cryoprotector containing ethylene glycol and providing transparency of the environment at the set heat exchange rates is received. The minimum concentration of vitrification solution of a cryoprotector for cryoconservation of mammals embryos (53 % [v/v]) consisting of ethylene glycol and sucrose (in the ratio 2:1) which provides transparency of the environment at a rate of 6´103 0С/min. is established

    Modeling Escape from a One-Dimensional Potential Well at Zero or Very Low Temperatures

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    The process of activation out a one-dimensional potential is investigated systematically in zero and nonzero temperature conditions. The features of the potential are traced through statistical escape out of its wells whose depths are tuned in time by a forcing term. The process is carried out on the damped pendulum system imposing specific initial conditions on the potential variable. While for relatively high values of the dissipation the statistical properties follow a behavior that can be derived from the standard Kramers model, decreasing the dissipation we observe responses/deviations which have regular dependencies on initial conditions, temperature, and loss parameter itself. It is shown that failures of the thermal activation model are originated at low temperatures, and very low dissipation, by the initial conditions and intrinsic, namely T=0, characteristic oscillations of the potential-generated dynamical equation.Comment: 25 pages and 13 Figure

    Cytogenetics in the Study of Chromosomal Rearrangement during Wheat Evolution and Breeding

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    Cytogenetic methods such as chromosome banding and in situ hybridization remain relevant in the post-genomic era, especially for allopolyploid species where genome duplication in some cases makes it difficult to assess the reorganization of chromosomes during evolution. In this review, we give a brief description of cytogenetic methods for the analysis of homoeological chromosomes in cereals. Emphasis is placed on the development of methods for the study of polyploid wheat and its progenitors and on tandem repeats and retrotransposons as markers to evaluate chromosome reorganization throughout evolution and breeding. The most effective cytological probes used for the identification of chromosomes in wheat and Triticeae species by fluorescence and genomic in situ hybridization are described. Particular attention is paid to ribosomal genes used as markers in phylogenetic studies and for chromosome identification. Utility of these cytogenetic methods in the evaluation of breeding lines is demonstrated. A strategy for cytological analysis of wheat hybrids according to the degree of relationships between the species involved in crosses is also discussed

    Determination of technological parameters for continiuous casting of a hollow pipe billet

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    This article presents a method for calculating the speed of a hollow steel billet continuous casting for the seamless hot-rolled pipes production. As the initial data, used the values of the technological parameters of a round pipe billet production at the Pavlodar branch of LLP “KSP Steel” and physical modeling data of a hollow aluminum billet continuous casting at the laboratory facility of Toraighyrov University. The recalculation of the modeling results into the actual volumes of industrial production was carried out according to the condition of the similarity criterion of Fourier numbers. The casting speed of a steel hollow billet are determined, the increase of which, compared with a solid billet, amounted to 16 %

    Relationship between homoeologous regulatory and structural genes in allopolyploid genome – A case study in bread wheat

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    <p>Abstract</p> <p>Background</p> <p>The patterns of expression of homoeologous genes in hexaploid bread wheat have been intensively studied in recent years, but the interaction between structural genes and their homoeologous regulatory genes remained unclear. The question was as to whether, in an allopolyploid, this interaction is genome-specific, or whether regulation cuts across genomes. The aim of the present study was cloning, sequence analysis, mapping and expression analysis of <it>F3H </it>(flavanone 3-hydroxylase – one of the key enzymes in the plant flavonoid biosynthesis pathway) homoeologues in bread wheat and study of the interaction between <it>F3H </it>and their regulatory genes homoeologues – <it>Rc </it>(red coleoptiles).</p> <p>Results</p> <p>PCR-based cloning of <it>F3H </it>sequences from hexaploid bread wheat (<it>Triticum aestivum </it>L.), a wild tetraploid wheat (<it>T. timopheevii</it>) and their putative diploid progenitors was employed to localize, physically map and analyse the expression of four distinct bread wheat <it>F3H </it>copies. Three of these form a homoeologous set, mapping to the chromosomes of homoeologous group 2; they are highly similar to one another at the structural and functional levels. However, the fourth copy is less homologous, and was not expressed in anthocyanin pigmented coleoptiles. The presence of dominant alleles at the <it>Rc-1 </it>homoeologous loci, which are responsible for anthocyanin pigmentation in the coleoptile, was correlated with <it>F3H </it>expression in pigmented coleoptiles. Each dominant <it>Rc-1 </it>allele affected the expression of the three <it>F3H </it>homoeologues equally, but the level of <it>F3H </it>expression was dependent on the identity of the dominant <it>Rc-1 </it>allele present. Thus, the homoeologous <it>Rc-1 </it>genes contribute more to functional divergence than do the structural <it>F3H </it>genes.</p> <p>Conclusion</p> <p>The lack of any genome-specific relationship between <it>F3H-1 </it>and <it>Rc-1 </it>implies an integrative evolutionary process among the three diploid genomes, following the formation of hexaploid wheat. Regulatory genes probably contribute more to the functional divergence between the wheat genomes than do the structural genes themselves. This is in line with the growing consensus which suggests that although heritable morphological traits are determined by the expression of structural genes, it is the regulatory genes which are the prime determinants of allelic identity.</p

    Penggunaan Bahasa oleh Moderator Debat Pasangan Calon Presiden dan Wakil Presiden Tahun 2014

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    The reason of the researcher to observe the Presidential and Vice Presidential candidates debate is because of this debate is a formal event which requires formal language. Thus, it is suitable to observe how to speak the language properly. This research applies descriptive method and qualitative form. Research data, such as pronunciation, diction, intonation, and effective sentences. Technique of collecting data is documentary study. Tools of collecting data are the researcher (key instrument) and data tables. Based on the analysis of data on the language used by moderator of presidential and vice presidential candidates debate 2014 can be decuded 478 pronunciation mistakes, 28 diction mistakes, 13 intonation mistakes, and 59 ineffective sentences mistakes

    A WIDE DISTRIBUTION OF A NEW VRN-B1c ALLELE OF WHEAT TRITICUM AESTIVUM L. IN RUSSIA, UKRAINE AND ADJACENT REGIONS: A LINK WITH THE HEADING TIME AND ADAPTIVE POTENTIAL

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    The adaptation of common wheat (T. aestivum L.) to diverse environmental conditions is greatly under the control of genes involved in determination of vernalization response (Vrn-1 genes). It was found that the variation in common wheat heading time is affected not only by combination of Vrn-1 homoeoalleles but also by multiple alleles at a separate Vrn-1 locus. Previously, we described the Vrn-B1c allele from T.aestivum cv. 'Saratovskaya 29' and found significant differences in the structure of the first (1st) intron of this allele when compared to another highly abundant Vrn-B1a allele, specifically, the deletion of 0.8 kb coupled with the duplication of 0.4 kb. We suggested that the changes in the intron 1 of Vrn-B1c allele caused earlier ear emergence in the near-isogenic line and cultivars, carrying this allele. In this study we investigate the distribution of the Vrn-B1c allele in a wide set of spring wheat cultivars from Russia, Ukraine and adjacent regions. The analysis revealed that 40% of Russian and 53% of Ukranian spring wheat cultivars contain the Vrn-B1c allele. The high distribution of the Vrn-B1c allele can be explained by a frequent using of 'Saratovskaya 29' in the breeding process inside the studied area. From the other hand, the predominance of the Vrn-B1c allele among cultivars cultivated in West Siberia and Kazakhstan may be due to the selective advantage of this allele for the region where there is a high risk of early fall frosts
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