2,290 research outputs found
The O-specific polysaccharide structure and biosynthetic gene cluster of Yersinia pseudotuberculosis serotype O:11
No full textIn the Yersinia pseudotuberculosis serotyping scheme, 21 serotypes are present originating from about 30 different O-factors distributed within the species. With regard to the chemical structures of lipopolysaccharides (LPSs) and the genetic basis of their biosynthesis, a number, but not all, of Y. pseudotuberculosis strains representing different serotypes have been investigated. In order to present an overall picture of the relationship between genetics and structures, we have been working on the genetics and structures of various Y. pseudotuberculosis O-specific polysaccharides (OPSs). Here, we present a structural and genetic analysis of the Y. pseudotuberculosis serotype O:11 OPS. Our results showed that this OPS structure has the same backbone as that of Y. pseudotuberculosis O:1b, but with a 6d-L-Altf side-branch instead of Parf. The 30 end of the gene cluster is the same as that for O:1b and has the genes for synthesis of the backbone and for processing the completed repeat unit. The 50 end has genes for synthesis of 6d-L-Altf and its transfer to the repeating unit backbone. The pathway for the synthesis of the 6d-L-Altf appears to be different from that for 6d-L-Altp in Y. enterocolitica O:3. The chemical structure of the O:11 repeating unit i
Characterization of the specific O-polysaccharide structure and biosynthetic gene cluster of Yersinia pseudotuberculosis serotype O:15
No full textYersinia pseudotuberculosis serotyping scheme contains 21 serotypes based on the distribution of about 30 different O-factors within the species. The chemical structures of LPSs and the genetic basis of their biosynthesis has been determined for a number of Y. pseudotuberculosis strains representing different serotypes; thus, an overall picture of the relationship between genetics and structures is emerging. In this work, we have performed a structural and genetic analysis of the Y. pseudotuberculosis serotype O:15 O-specific polysaccharide. Our results showed that the set-up of the Y. pseudotuberculosis O:15 gene cluster is a hybrid between those of Y. pseudotuberculosis serotypes O:1b and O:5a, possibly due to a single recombination event. The hybrid nature could also be seen in the structure of the O-specific polysaccharide repeating unit pentasaccharide. It contains a tetrameric backbone identical to that of O:5a while the branching paratofuranose residue is identical to that of O:1b
The genetics and structure of the O-specific polysaccharide of Yersinia pseudotuberculosis serotype O:10 and its relationship to Escherichia coli O111 and Salmonella enterica O35.
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The O-specific polysaccharide (OPS) is a variable constituent of the lipopolysaccharide of Gram-negative bacteria. The polymorphic nature of OPSs within a species is usually first defined serologically, and the current serotyping scheme for Yersinia pseudotuberculosis consists of 21 O serotypes of which 15 have been characterized genetically and structurally. Here, we present the structure and DNA sequence of Y. pseudotuberculosis O:10 OPS. The O unit consists of one residue each of d-galactopyranose, N-acetyl-d-galactosamine (2-amino-2-deoxy-d-galactopyranose) and d-glucopyranose in the backbone, with two colitose (3,6-dideoxy-l-xylo-hexopyranose) side-branch residues. This structure is very similar to that shared by Escherichia coli O111 and Salmonella enterica O35. The gene cluster sequences of these serotypes, however, have only low levels of similarity to that of Y. pseudotuberculosis O:10, although there is significant conservation of gene order. Within Y. pseudotuberculosis, the O10 structure is most closely related to the O:6 and O:7 structures
Dr. O. v. Holst ex librise
No full texthttp://www.lib.unideb.huDebreceni Egyetem Egyetemi és Nemzeti KönyvtárA kép alján egy nyitott könyv, mellette, mögötte további könyvek és egy tinta és toll tartó sorakoznak. Fölötte feliratszalagon: " Dr. O. v. Holst". Efölött egyszer hasított címer, rajta balra fakopáncs, jobbra fiait vérével tápláló pelikán, feje fölött 3 csillag. Az oromdíszen ismétlődik a pelikán-figura.. E mögött húzódik az "ex libris" felirat. A kép alatt vélhetően a szerző aláírása és a dátum szerepel. A hátoldalon kézzel írva a következő olvasható:" Stützkopf Würzburg 1898".metsze
Acetyl substitution of the O-specific caryan from the lipopolysaccharide of Pseudomonas (Burkholderia) caryophylli leads to a block pattern
No full textMigration and Money - What Determines Remittances?: Evidence from Germany
No full textThe determinants of migrants' remittances are the subject of this study based on German SOEP data. For our analysis of the probability and amount of remittances, we do not restrict ourselves on immigrants with a foreign citizenship, but focus on all individuals with a migration background. Major findings are: first, the degree of integration into German society matters. Second, the probability to remit is not dominated by income. Third, foreigners living in Germany are not a homogenous group concerning their remittance behavior: people with Turkish and former Yugoslavian citizenship, who are facing a comparable strong pressure for return migration, remit significantly more than others. The study points to potentially interesting directions for future research: (a) deeper investigations of the extent to which the legal status of the migrant influences cross-border transfer behavior and (b) reconsidering the theoretical arguments since the motive for remittances might have changed during the ongoing globalization process..Remittances, international migration, altruism
Policy Analysis Using a Business Simulation Game
No full textDespite numerous studies on farmers' responses to changing irrigation water policies, uncertainties remain about the potential of water pricing schemes and water quotas to reduce irrigation. Thus far, policy impact analysis is predominantly based upon rational choice models that assume behavioral assumptions, such as a perfectly rational profit-maximizing decision maker. Also, econometric techniques are applied which could lack internal validity due to uncontrolled field data. Furthermore, such techniques are not capable of identifying ill-designed policies prior to their implementation. With this in mind, we apply a business simulation game for ex ante policy impact analysis of irrigation water policies at the farm level. Our approach has the potential to reveal the policy-induced behavioral change of the participants in a controlled environment. To do so, we investigate how real farmers from Germany, in an economic experiment, respond to a water pricing scheme and a water quota intending to reduce irrigation. In the business simulation game, the participants manage a virtual cash-crop farm for which they make crop allocation and irrigation decisions during several production periods, while facing uncertain product prices and weather conditions. The results reveal that a water quota is able to reduce mean irrigation applications, while a water pricing scheme does not have an impact, even though both policies exhibit equal income effects for the farmers. However, both policies appear to increase the variation of irrigation applications. Compared to a perfectly rational profit-maximizing decision maker, the participants apply less irrigation on average, both when irrigation is not restricted and when a water pricing scheme applies. Moreover, the participants' risk attitude affects the irrigation decisions
The structure of the O-specific polysaccharide of the lipopolysaccharide from Bulkholderia gladioli pv. agaricicola
No full textA neutral O-specific polysaccharide contg. D-mannose, D-rhamnose and D-galactose was obtained by mild acid hydrolysis of the lipopolysaccharide of the plant pathogenic bacterium Burkholderia gladioli pv. agaricicola. By means of compositional analyses and NMR spectroscopy, the chem. repeating unit of the polymer was identified as a linear trisaccharide of the structure shown below, in which the mannose residue was quant. acetylated at C-2
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