43 research outputs found

    Процесс оценки уровня освоения профессиональных компетенций бакалавров на примере специальности «Землеустройство и кадастры»

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    В процессе исследования проводился анализ процесса формирования профессиональных компетенций бакалавров, разработка тестовых заданий для измерения профессиональных компетенций бакалавров, измерение профессиональных компетенций бакалавров. В результате исследования выявлены проблемы в процессе оценке уровня сформированности профессиональных компетенций бакалавров.In the course of the research, the analysis of the process of formation of professional competencies of bachelors was carried out, the development of test tasks to measure the professional competencies of bachelors, the measurement of professional competences of bachelors. As a result of the study, problems were identified in the process of assessing the level of formation of professional competencies of bachelors

    Galactan biosynthesis in snails: a comparative study of beta -(1 6) galactosyltransferases from Helix pomatia and Biomphalaria glabrata

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    Adult snails synthesize in their albumen glands a polysaccharide which is composed exclusively of D- or D- and L-galactose (Gal) residues which are interglycosidically linked by 1 → 3 and 1 → 6 bonds. It is the only carbohydrate source for embryos and freshly hatched snails. Two galactosyltransferases are described in this study which are most likely involved in the biosynthesis of this polysaccharide. One identified in Helix pomatia acts on oligosaccharides and could be used to synthesize a tetrasaccharide when the branched trisaccharide D-Gal-β-(1 → 3)-[D-Galβ-(1 → 6)]-D-Galβ-1 → OMe was offered as acceptor. This enzyme, requiring Mg++- and Mn++-ions for activity, introduced a linear β-(1 → 6) linkage at the terminal non-reducing ends and was not detected in Biomphalaria glabrata. The other enzyme, which introduced β-(1 → 6) linkages at subterminal D-Gal residues, thus forming branching points in the polysaccharide, was found in H. pomatia, Arianta arbustorum and B. glabrata with comparable activities. With the enzyme preparation of H. pomatia, up to four D-Gal residues were introduced into vicinal positions, forming single-membered side chains, if a hexasaccharide with five linearly β-(1 → 3)-linked D-Gal residues was offered as a acceptor. The multiple-branched structure formed is typical for snail galactans, making this enzyme a prime candidate for the branching enzyme in galactan synthesis. The enzyme activity could be solubilized and purified by affinity chromatography. In SDS-polyacrylamide electrophoresis, the Helix- derived eluate displayed two bands (68, 37 kDa) and that of Biomphalaria five bands (68, 63, 17.5; 15; 13 kDa). The purified material showed only 8% of the total activity of the crude extracts, but it could be shown that a phosphatase present in the crude extract can degrade UDP formed in the transfer reaction and thus drive the reaction to completion

    Neue Charakterisierungsmethoden von Polysacchariden. Teilvorhaben: Methodenentwicklung zur Bestimmung der Substituentenverteilung von Cellulose-und Staerkederivaten Schlussbericht

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    SIGLEAvailable from TIB Hannover: F96B1646+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

    New approaches to the analysis of enzymatically hydrolyzed methyl cellulose. Part 1. Investigation of the influence of structural parameters on the extent of degradation

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    Six methyl celluloses (MCs), one with a degree of substitution (DS) of 1.32 and five with DS between 1.83 and 1.88, were thoroughly investigated. Monomer composition and methyl distribution in the polymer chain were analyzed after total or partial random hydrolysis and appropriate derivatization with gas chromatography ( GC) and mass spectrometry (MS), respectively, and used as reference data. The same MCs were then hydrolyzed with an enzyme preparation of Trichoderma longibrachiatum and further investigated with size-exclusion chromatography with multiangle light scattering and refractive index detection (SEC-MALS/RI) and MS. Electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI) in combination with various MS analyzers were compared with respect to quantification of the degradation products directly and after perdeuteriomethylation. The methyl group distribution in the oligomeric fractions and the average DS as a function of chain length were calculated from ESI mass spectra. With help of the reference analysis, patterns could be corrected for the unspecific contribution of end groups. By labeling and ESI tandem MS, our knowledge about the tolerance of the enzymes' sub-sites with respect to the number of methyl groups could be improved
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