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Sample records for 0-atp-synthase aus acetobacterium

  1. Atrazine binds to F1F0-ATP synthase and inhibits mitochondrial function in sperm.

    PubMed

    Hase, Yasuyoshi; Tatsuno, Michiko; Nishi, Takeyuki; Kataoka, Kosuke; Kabe, Yasuaki; Yamaguchi, Yuki; Ozawa, Nobuaki; Natori, Michiya; Handa, Hiroshi; Watanabe, Hajime

    2008-02-01

    Atrazine is a widely used triazine herbicide. Although controversy still exists, a number of recent studies have described its adverse effects on various animals including humans. Of particular interest is its effects on reproductive capacity. In this study, we investigated the mechanisms underlying the adverse effects of atrazine, with a focus on its effects on sperm. Here we show evidence that mitochondrial F(1)F(0)-ATP synthase is a molecular target of atrazine. A series of experiments with sperm and isolated mitochondria suggest that atrazine inhibits mitochondrial function through F(1)F(0)-ATP synthase. Moreover, affinity purification using atrazine as a ligand demonstrates that F(1)F(0)-ATP synthase is a major atrazine-binding protein in cells. The inhibitory activity against mitochondria and F(1)F(0)-ATP synthase is not limited to atrazine but is likely to be applicable to other triazine-based compounds. Thus, our findings may have wide relevance to pharmacology and toxicology. PMID:18060860

  2. Crystallization of F 1F 0-ATP synthase from Chloroflexus aurantiacus

    NASA Astrophysics Data System (ADS)

    Kiselyova, O. I.; Shiryaeva, G. N.; Efremov, R. G.; Gordeliy, V. I.; Yaminsky, I. V.; Yanyushin, M. F.; Büldt, G.; Yaguzhinsky, L. S.

    2005-02-01

    Crystallization of F 1F 0-ATP synthase from thermophilic bacterium Chloroflexus aurantiacus was carried out in the present work. A new crystallization method based on slow detergent removal in a two-phase system, consisting of decane and protein solution, was developed. Three-dimensional protein crystals were grown by this method. Two-dimensional molecular lattice with unit cell parameters of a=28 nm, b=23 nm and φ=104° was observed by atomic force microscopy on their surface. Thickness of protein surface layer of the crystals was determined also. Model of the protein molecular packing of the crystals is suggested basing on the experimental data.

  3. An intermediate step in the evolution of ATPases: a hybrid F(0)-V(0) rotor in a bacterial Na(+) F(1)F(0) ATP synthase.

    PubMed

    Fritz, Michael; Klyszejko, Adriana L; Morgner, Nina; Vonck, Janet; Brutschy, Bernd; Muller, Daniel J; Meier, Thomas; Müller, Volker

    2008-05-01

    The Na(+) F(1)F(0) ATP synthase operon of the anaerobic, acetogenic bacterium Acetobacterium woodii is unique because it encodes two types of c subunits, two identical 8 kDa bacterial F(0)-like c subunits (c(2) and c(3)), with two transmembrane helices, and a 18 kDa eukaryal V(0)-like (c(1)) c subunit, with four transmembrane helices but only one binding site. To determine whether both types of rotor subunits are present in the same c ring, we have isolated and studied the composition of the c ring. High-resolution atomic force microscopy of 2D crystals revealed 11 domains, each corresponding to two transmembrane helices. A projection map derived from electron micrographs, calculated to 5 A resolution, revealed that each c ring contains two concentric, slightly staggered, packed rings, each composed of 11 densities, representing 22 transmembrane helices. The inner and outer diameters of the rings, measured at the density borders, are approximately 17 and 50 A. Mass determination by laser-induced liquid beam ion desorption provided evidence that the c rings contain both types of c subunits. The stoichiometry for c(2)/c(3) : c(1) was 9 : 1. Furthermore, this stoichiometry was independent of the carbon source of the growth medium. These analyses clearly demonstrate, for the first time, an F(0)-V(0) hybrid motor in an ATP synthase. PMID:18355313

  4. Metabolic Trade-offs in Yeast are Caused by F1F0-ATP synthase.

    PubMed

    Nilsson, Avlant; Nielsen, Jens

    2016-01-01

    Intermediary metabolism provides living cells with free energy and precursor metabolites required for synthesizing proteins, lipids, RNA and other cellular constituents, and it is highly conserved among living species. Only a fraction of cellular protein can, however, be allocated to enzymes of intermediary metabolism and consequently metabolic trade-offs may take place. One such trade-off, aerobic fermentation, occurs in both yeast (the Crabtree effect) and cancer cells (the Warburg effect) and has been a scientific challenge for decades. Here we show, using flux balance analysis combined with in vitro measured enzyme specific activities, that fermentation is more catalytically efficient than respiration, i.e. it produces more ATP per protein mass. And that the switch to fermentation at high growth rates therefore is a consequence of a high ATP production rate, provided by a limited pool of enzymes. The catalytic efficiency is also higher for cells grown on glucose compared to galactose and ethanol, which may explain the observed differences in their growth rates. The enzyme F1F0-ATP synthase (Complex V) was found to have flux control over respiration in the model, and since it is evolutionary conserved, we expect the trade-off to occur in organisms from all kingdoms of life. PMID:26928598

  5. Metabolic Trade-offs in Yeast are Caused by F1F0-ATP synthase

    PubMed Central

    Nilsson, Avlant; Nielsen, Jens

    2016-01-01

    Intermediary metabolism provides living cells with free energy and precursor metabolites required for synthesizing proteins, lipids, RNA and other cellular constituents, and it is highly conserved among living species. Only a fraction of cellular protein can, however, be allocated to enzymes of intermediary metabolism and consequently metabolic trade-offs may take place. One such trade-off, aerobic fermentation, occurs in both yeast (the Crabtree effect) and cancer cells (the Warburg effect) and has been a scientific challenge for decades. Here we show, using flux balance analysis combined with in vitro measured enzyme specific activities, that fermentation is more catalytically efficient than respiration, i.e. it produces more ATP per protein mass. And that the switch to fermentation at high growth rates therefore is a consequence of a high ATP production rate, provided by a limited pool of enzymes. The catalytic efficiency is also higher for cells grown on glucose compared to galactose and ethanol, which may explain the observed differences in their growth rates. The enzyme F1F0-ATP synthase (Complex V) was found to have flux control over respiration in the model, and since it is evolutionary conserved, we expect the trade-off to occur in organisms from all kingdoms of life. PMID:26928598

  6. Mitochondrial F1F0-ATP synthase and organellar internal architecture.

    PubMed

    Velours, Jean; Dautant, Alain; Salin, Bénédicte; Sagot, Isabelle; Brèthes, Daniel

    2009-10-01

    The mitochondrial F(1)F(0)-ATP synthase adopts supramolecular structures. The interaction domains between monomers involve components belonging to the F(0) domains. In Saccharomyces cerevisiae, alteration of these components destabilizes the oligomeric structures, leading concomitantly to the appearance of monomeric species of ATP synthase and anomalous mitochondrial morphologies in the form of onion-like structures. The mitochondrial ultrastructure at the cristae level is thus modified. Electron microscopy on cross-sections of wild type mitochondria display many short cristae with narrowed intra-cristae space, whereas yeast mutants defected in supramolecular ATP synthases assembly present a low number of large lamellar cristae of constant thickness and traversing the whole organelle. The growth of these internal structures leads finally to mitochondria with sphere-like structures with a mean diameter of 1 microm that are easily identified by epifluorescence microscopy. As a result, ATP synthase is an actor of the mitochondrial ultrastructure in yeast. This paper reviews the ATP synthase components whose modifications lead to anomalous mitochondrial morphology and also provides a schema showing the formation of the so-called onion-like structures. PMID:19703649

  7. Cruentaren A Binds F1F0 ATP Synthase To Modulate the Hsp90 Protein Folding Machinery

    PubMed Central

    2015-01-01

    The molecular chaperone Hsp90 requires the assistance of immunophilins, co-chaperones, and partner proteins for the conformational maturation of client proteins. Hsp90 inhibition represents a promising anticancer strategy due to the dependence of numerous oncogenic signaling pathways upon Hsp90 function. Historically, small molecules have been designed to inhibit ATPase activity at the Hsp90 N-terminus; however, these molecules also induce the pro-survival heat shock response (HSR). Therefore, inhibitors that exhibit alternative mechanisms of action that do not elicit the HSR are actively sought. Small molecules that disrupt Hsp90-co-chaperone interactions can destabilize the Hsp90 complex without induction of the HSR, which leads to inhibition of cell proliferation. In this article, selective inhibition of F1F0 ATP synthase by cruentaren A was shown to disrupt the Hsp90-F1F0 ATP synthase interaction and result in client protein degradation without induction of the HSR. PMID:24450340

  8. Structure of the nucleotide-binding subunit B of the energy producer A1A0 ATP synthase in complex with adenosine diphosphate.

    PubMed

    Kumar, Anil; Manimekalai, Malathy Sony Subramanian; Grüber, Gerhard

    2008-11-01

    A1A0 ATP synthases are the major energy producers in archaea. Like the related prokaryotic and eukaryotic F1F0 ATP synthases, they are responsible for most of the synthesis of adenosine triphosphate. The catalytic events of A1A0 ATP synthases take place inside the A3B3 hexamer of the A1 domain. Recently, the crystallographic structure of the nucleotide-free subunit B of Methanosarcina mazei Gö1 A1A0 ATP synthase has been determined at 1.5 A resolution. To understand more about the nucleotide-binding mechanism, a protocol has been developed to crystallize the subunit B-ADP complex. The crystallographic structure of this complex has been solved at 2.7 A resolution. The ADP occupies a position between the essential phosphate-binding loop and amino-acid residue Phe149, which are involved in the binding of the antibiotic efrapeptin in the related F1F0 ATP synthases. This trapped ADP location is about 13 A distant from its final binding site and is therefore called the transition ADP-binding position. In the trapped ADP position the structure of subunit B adopts a different conformation, mainly in its C-terminal domain and also in the final nucleotide-binding site of the central alphabeta-domain. This atomic model provides insight into how the substrate enters into the nucleotide-binding protein and thereby into the catalytic A3B3 domain. PMID:19020348

  9. Mutagenic analysis of the a subunit of the F1F0 ATP synthase in Escherichia coli: Gln-252 through Tyr-263.

    PubMed

    Hartzog, P E; Cain, B D

    1993-03-01

    The a subunit of F1F0 ATP synthase contains a highly conserved region near its carboxyl terminus which is thought to be important in proton translocation. Cassette site-directed mutagenesis was used to study the roles of four conserved amino acids Gln-252, Phe-256, Leu-259, and Tyr-263. Substitution of basic amino acids at each of these four sites resulted in marked decreases in enzyme function. Cells carrying a subunit mutations Gln-252-->Lys, Phe-256-->Arg, Leu-259-->Arg, and Tyr-263-->Arg all displayed growth characteristics suggesting substantial loss of ATP synthase function. Studies of both ATP-driven proton pumping and proton permeability of stripped membranes indicated that proton translocation through F0 was affected by the mutations. Other mutations, such as the Phe-256-->Asp mutation, also resulted in reduced enzyme activity. However, more conservative amino acid substitutions generated at these same four positions produced minimal losses of F1F0 ATP synthase. The effects of mutations and, hence, the relative importance of the amino acids for enzyme function appeared to decrease with proximity to the carboxyl terminus of the a subunit. The data are most consistent with the hypothesis that the region between Gln-252 and Tyr-263 of the a subunit has an important structural role in F1F0 ATP synthase. PMID:8383111

  10. Role of the N-terminal signal peptide in the membrane insertion of Aquifex aeolicus F1F0 ATP synthase c-subunit.

    PubMed

    Zhang, Chunli; Marcia, Marco; Langer, Julian D; Peng, Guohong; Michel, Hartmut

    2013-07-01

    Rotary ATPases are membrane protein complexes that couple ATP hydrolysis to ion translocation across the membrane. Overall, they are evolutionarily well conserved, but the N-terminal segments of their rotary subunits (c-subunits) possess different lengths and levels of hydrophobicity across species. By analyzing the N-terminal variability, we distinguish four phylogenetic groups of c-subunits (groups 1-4). We characterize a member of group 2, the c-subunit from Aquifex aeolicus F1F0 ATP synthase, both in native cells and in a heterologous expression system. We demonstrate that its N-terminal segment forms a signal peptide with signal recognition particle (SRP) recognition features and is obligatorily required for membrane insertion. Based on our study and on previous characterizations of c-subunits from other organisms, we propose that c-subunits follow different membrane insertion pathways. PMID:23663226

  11. Hydrogenase from Acetobacterium woodii.

    PubMed

    Ragsdale, S W; Ljungdahl, L G

    1984-11-01

    Hydrogenase from fructose-grown cells of Acetobacterium woodii has been purified 70-fold to a specific activity of 3,500 mumol hydrogen oxidized per min per mg of protein measured at 35 degrees C and pH 7.6 with methyl viologen as electron acceptor. At the same conditions with reduced methyl viologen as electron donor the enzyme catalyzes the evolvement of 440 mumol of H2 per min per mg of protein. The enzyme was found in the soluble portion of the cell, indicating that it is either not membrane-bound or is loosely associated with the membrane. The purified enzyme, which does not contain nickel, exhibits spectroscopic properties similar to the iron-sulfur hydrogenase of Clostridium pasteurianum. The enzyme is strongly inhibited by carbon monoxide, with 50% inhibition occurring at approximately 7 nM CO. Ferredoxin, flavodoxin, and carbon monoxide dehydrogenase are reduced in hydrogen-dependent reaction by the A. woodi hydrogenase. PMID:6393895

  12. Nickel requirement of Acetobacterium woodii.

    PubMed

    Diekert, G; Ritter, M

    1982-08-01

    Growth of Acetobacterium woodii on H2 and CO2 rather than on fructose was dependent on nickel. Nickel-deprived cultures growing on fructose did not synthesize acetate from CO2; under these conditions hydrogen formation was used as the electron sink. The data indicate that nickel is involved in CO2 reduction to acetate in A. woodii. PMID:6807954

  13. Nickel requirement of Acetobacterium woodii.

    PubMed Central

    Diekert, G; Ritter, M

    1982-01-01

    Growth of Acetobacterium woodii on H2 and CO2 rather than on fructose was dependent on nickel. Nickel-deprived cultures growing on fructose did not synthesize acetate from CO2; under these conditions hydrogen formation was used as the electron sink. The data indicate that nickel is involved in CO2 reduction to acetate in A. woodii. PMID:6807954

  14. CO Metabolism in the Acetogen Acetobacterium woodii

    PubMed Central

    Bertsch, Johannes

    2015-01-01

    The Wood-Ljungdahl pathway allows acetogenic bacteria to grow on a number of one-carbon substrates, such as carbon dioxide, formate, methyl groups, or even carbon monoxide. Since carbon monoxide alone or in combination with hydrogen and carbon dioxide (synthesis gas) is an increasingly important feedstock for third-generation biotechnology, we studied CO metabolism in the model acetogen Acetobacterium woodii. When cells grew on H2-CO2, addition of 5 to 15% CO led to higher final optical densities, indicating the utilization of CO as a cosubstrate. However, the growth rate was decreased by the presence of small amounts of CO, which correlated with an inhibition of H2 consumption. Experiments with resting cells revealed that the degree of inhibition of H2 consumption was a function of the CO concentration. Since the hydrogen-dependent CO2 reductase (HDCR) of A. woodii is known to be very sensitive to CO, we speculated that cells may be more tolerant toward CO when growing on formate, the product of the HDCR reaction. Indeed, addition of up to 25% CO did not influence growth rates on formate, while the final optical densities and the production of acetate increased. Higher concentrations (75 and 100%) led to a slight inhibition of growth and to decreasing rates of formate and CO consumption. Experiments with resting cells revealed that the HDCR is a site of CO inhibition. In contrast, A. woodii was not able to grow on CO as a sole carbon and energy source, and growth on fructose-CO or methanol-CO was not observed. PMID:26092462

  15. CO Metabolism in the Acetogen Acetobacterium woodii.

    PubMed

    Bertsch, Johannes; Müller, Volker

    2015-09-01

    The Wood-Ljungdahl pathway allows acetogenic bacteria to grow on a number of one-carbon substrates, such as carbon dioxide, formate, methyl groups, or even carbon monoxide. Since carbon monoxide alone or in combination with hydrogen and carbon dioxide (synthesis gas) is an increasingly important feedstock for third-generation biotechnology, we studied CO metabolism in the model acetogen Acetobacterium woodii. When cells grew on H2-CO2, addition of 5 to 15% CO led to higher final optical densities, indicating the utilization of CO as a cosubstrate. However, the growth rate was decreased by the presence of small amounts of CO, which correlated with an inhibition of H2 consumption. Experiments with resting cells revealed that the degree of inhibition of H2 consumption was a function of the CO concentration. Since the hydrogen-dependent CO2 reductase (HDCR) of A. woodii is known to be very sensitive to CO, we speculated that cells may be more tolerant toward CO when growing on formate, the product of the HDCR reaction. Indeed, addition of up to 25% CO did not influence growth rates on formate, while the final optical densities and the production of acetate increased. Higher concentrations (75 and 100%) led to a slight inhibition of growth and to decreasing rates of formate and CO consumption. Experiments with resting cells revealed that the HDCR is a site of CO inhibition. In contrast, A. woodii was not able to grow on CO as a sole carbon and energy source, and growth on fructose-CO or methanol-CO was not observed. PMID:26092462

  16. 2,3-Butanediol Metabolism in the Acetogen Acetobacterium woodii.

    PubMed

    Hess, Verena; Oyrik, Olga; Trifunović, Dragan; Müller, Volker

    2015-07-01

    The acetogenic bacterium Acetobacterium woodii is able to reduce CO2 to acetate via the Wood-Ljungdahl pathway. Only recently we demonstrated that degradation of 1,2-propanediol by A. woodii was not dependent on acetogenesis, but that it is disproportionated to propanol and propionate. Here, we analyzed the metabolism of A. woodii on another diol, 2,3-butanediol. Experiments with growing and resting cells, metabolite analysis and enzymatic measurements revealed that 2,3-butanediol is oxidized in an NAD(+)-dependent manner to acetate via the intermediates acetoin, acetaldehyde, and acetyl coenzyme A. Ethanol was not detected as an end product, either in growing cultures or in cell suspensions. Apparently, all reducing equivalents originating from the oxidation of 2,3-butanediol were funneled into the Wood-Ljungdahl pathway to reduce CO2 to another acetate. Thus, the metabolism of 2,3-butanediol requires the Wood-Ljungdahl pathway. PMID:25934628

  17. 2,3-Butanediol Metabolism in the Acetogen Acetobacterium woodii

    PubMed Central

    Hess, Verena; Oyrik, Olga; Trifunović, Dragan

    2015-01-01

    The acetogenic bacterium Acetobacterium woodii is able to reduce CO2 to acetate via the Wood-Ljungdahl pathway. Only recently we demonstrated that degradation of 1,2-propanediol by A. woodii was not dependent on acetogenesis, but that it is disproportionated to propanol and propionate. Here, we analyzed the metabolism of A. woodii on another diol, 2,3-butanediol. Experiments with growing and resting cells, metabolite analysis and enzymatic measurements revealed that 2,3-butanediol is oxidized in an NAD+-dependent manner to acetate via the intermediates acetoin, acetaldehyde, and acetyl coenzyme A. Ethanol was not detected as an end product, either in growing cultures or in cell suspensions. Apparently, all reducing equivalents originating from the oxidation of 2,3-butanediol were funneled into the Wood-Ljungdahl pathway to reduce CO2 to another acetate. Thus, the metabolism of 2,3-butanediol requires the Wood-Ljungdahl pathway. PMID:25934628

  18. Carbonic anhydrase in Acetobacterium woodii and other acetogenic bacteria.

    PubMed

    Braus-Stromeyer, S A; Schnappauf, G; Braus, G H; Gössner, A S; Drake, H L

    1997-11-01

    Acetobacterium woodii, Acetohalobium arabaticum, Clostridium formicoaceticum, and Sporomusa silvacetica were found to contain carbonic anhydrase (CA). Minimal to no CA activity was detected in Moorella thermoautotrophica, Moorella thermoacetica subsp. "pratumsolum," Sporomusa termitida, and Thermoanaerobacter kivui. Of the acetogens tested, A. woodii had the highest CA specific activity, approximately 14 U mg of protein(-1), in extracts of either glucose- or H2-CO2-cultivated cells. CA of A. woodii was cytoplasmic and was purified approximately 300-fold to a specific activity of 5,236 U mg of protein(-1). Intracellular acetate concentrations inhibited CA activity of A. woodii by 50 to 85%, indicating that intracellular acetate may affect in situ CA activity. PMID:9371472

  19. AusEinetter, 1997.

    ERIC Educational Resources Information Center

    AusEinetter, 1997

    1997-01-01

    This document comprises the two AusEinetter newsletters published in 1997. The first newletter describes the background and structure of Australia's Early Intervention Network for Mental Health in Young People (AusEinet) and discusses the necessity of early intervention for mental health issues in young people 5-25 years of age. The following…

  20. The ins and outs of Na(+) bioenergetics in Acetobacterium woodii.

    PubMed

    Schmidt, Silke; Biegel, Eva; Müller, Volker

    2009-06-01

    The acetogenic bacterium Acetobacterium woodii uses a transmembrane electrochemical sodium ion potential for bioenergetic reactions. A primary sodium ion potential is established during carbonate (acetogenesis) as well as caffeate respiration. The electrogenic Na(+) pump connected to the Wood-Ljungdahl pathway (acetogenesis) still remains to be identified. The pathway of caffeate reduction with hydrogen as electron donor was investigated and the only membrane-bound activity was found to be a ferredoxin-dependent NAD(+) reduction. This exergonic electron transfer reaction may be catalyzed by the membrane-bound Rnf complex that was discovered recently and is suggested to couple exergonic electron transfer from ferredoxin to NAD(+) to the vectorial transport of Na(+) across the cytoplasmic membrane. Rnf may also be involved in acetogenesis. The electrochemical sodium ion potential thus generated is used to drive endergonic reactions such as flagellar rotation and ATP synthesis. The ATP synthase is a member of the F(1)F(O) class of enzymes but has an unusual and exceptional feature. Its membrane-embedded rotor is a hybrid made of F(O) and V(O)-like subunits in a stoichiometry of 9:1. This stoichiometry is apparently not variable with the growth conditions. The structure and function of the Rnf complex and the Na(+) F(1)F(O) ATP synthase as key elements of the Na(+) cycle in A. woodii are discussed. PMID:19167341

  1. Production and Utilization of Ethanol by the Homoacetogen Acetobacterium woodii.

    PubMed

    Buschhorn, H; Dürre, P; Gottschalk, G

    1989-07-01

    Acetobacterium woodii formed ethanol as a fermentation product in addition to acetate when the phosphate concentration of the medium was between 0.2 and 8.4 mM. Considerable amounts of alanine were also found (2 to 11 mM). Supplementation with phosphate caused a shift to acetate as the only end product. Ethanol could also serve as a substrate for A. woodii. The fermentation yielded predominantly acetate and was strictly dependent on high bicarbonate concentrations. 1-Propanol, 1-butanol, and 1-pentanol were converted to the corresponding fatty acids but allowed only marginal growth. A. wieringae and A. carbinolicum grown under identical conditions were also able to form ethanol, and A. wieringae could use ethanol as a substrate, too. Alcohol dehydrogenase and acetaldehyde dehydrogenase activities were determined in A. woodii. Activity stains of polyacrylamide gels with crude extracts allowed the detection of acetaldehyde dehydrogenase but not of alcohol dehydrogenase. Trace amounts of methane were detected during growth of A. woodii on glucose and ethanol. PMID:16347978

  2. Acetone production with metabolically engineered strains of Acetobacterium woodii.

    PubMed

    Hoffmeister, Sabrina; Gerdom, Marzena; Bengelsdorf, Frank R; Linder, Sonja; Flüchter, Sebastian; Öztürk, Hatice; Blümke, Wilfried; May, Antje; Fischer, Ralf-Jörg; Bahl, Hubert; Dürre, Peter

    2016-07-01

    Expected depletion of oil and fossil resources urges the development of new alternative routes for the production of bulk chemicals and fuels beyond petroleum resources. In this study, the clostridial acetone pathway was used for the formation of acetone in the acetogenic bacterium Acetobacterium woodii. The acetone production operon (APO) containing the genes thlA (encoding thiolase A), ctfA/ctfB (encoding CoA transferase), and adc (encoding acetoacetate decarboxylase) from Clostridium acetobutylicum were cloned under the control of the thlA promoter into four vectors having different replicons for Gram-positives (pIP404, pBP1, pCB102, and pCD6). Stable replication was observed for all constructs. A. woodii [pJIR_actthlA] achieved the maximal acetone concentration under autotrophic conditions (15.2±3.4mM). Promoter sequences of the genes ackA from A. woodii and pta-ack from C. ljungdahlii were determined by primer extension (PEX) and cloned upstream of the APO. The highest acetone production in recombinant A. woodii cells was achieved using the promoters PthlA and Ppta-ack. Batch fermentations using A. woodii [pMTL84151_actthlA] in a bioreactor revealed that acetate concentration had an effect on the acetone production, due to the high Km value of the CoA transferase. In order to establish consistent acetate concentration within the bioreactor and to increase biomass, a continuous fermentation process for A. woodii was developed. Thus, acetone productivity of the strain A. woodii [pMTL84151_actthlA] was increased from 1.2mgL(-1)h(-1) in bottle fermentation to 26.4mgL(-1)h(-1) in continuous gas fermentation. PMID:26971669

  3. Regulation of caffeate respiration in the acetogenic bacterium Acetobacterium woodii.

    PubMed

    Dilling, Sabrina; Imkamp, Frank; Schmidt, Silke; Müller, Volker

    2007-06-01

    The anaerobic acetogenic bacterium Acetobacterium woodii can conserve energy by oxidation of various substrates coupled to either carbonate or caffeate respiration. We used a cell suspension system to study the regulation and kinetics of induction of caffeate respiration. After addition of caffeate to suspensions of fructose-grown cells, there was a lag phase of about 90 min before caffeate reduction commenced. However, in the presence of tetracycline caffeate was not reduced, indicating that de novo protein synthesis is required for the ability to respire caffeate. Induction also took place in the presence of CO(2), and once a culture was induced, caffeate and CO(2) were used simultaneously as electron acceptors. Induction of caffeate reduction was also observed with H(2) plus CO(2) as the substrate, but the lag phase was much longer. Again, caffeate and CO(2) were used simultaneously as electron acceptors. In contrast, during oxidation of methyl groups derived from methanol or betaine, acetogenesis was the preferred energy-conserving pathway, and caffeate reduction started only after acetogenesis was completed. The differential flow of reductants was also observed with suspensions of resting cells in which caffeate reduction was induced prior to harvest of the cells. These cell suspensions utilized caffeate and CO(2) simultaneously with fructose or hydrogen as electron donors, but CO(2) was preferred over caffeate during methyl group oxidation. Caffeate-induced resting cells could reduce caffeate and also p-coumarate or ferulate with hydrogen as the electron donor. p-Coumarate or ferulate also served as an inducer for caffeate reduction. Interestingly, caffeate-induced cells reduced ferulate in the absence of an external reductant, indicating that caffeate also induces the enzymes required for oxidation of the methyl group of ferulate. PMID:17416687

  4. Draft Genome Sequence of Acetobacterium bakii DSM 8239, a Potential Psychrophilic Chemical Producer through Syngas Fermentation

    PubMed Central

    Hwang, Soonkyu; Song, Yoseb

    2015-01-01

    Acetobacterium bakii DSM 8239 is an anaerobic, psychrophilic, and chemolithoautotrophic bacterium that is a potential platform for producing commodity chemicals from syngas fermentation. We report here the draft genome sequence of A. bakii DSM 8239 (4.14 Mb) to elucidate its physiological and metabolic properties related to syngas fermentation. PMID:26404601

  5. Structure of the Na+-driven flagellum from the homoacetogenic bacterium Acetobacterium woodii.

    PubMed

    Aufurth, S; Madkour, M; Mayer, F; Müller, V

    1998-09-01

    The Na+-dependent flagellum of Acetobacterium woodii was characterised. Flagellin and whole flagella were purified and analysed by SDS-PAGE and electron microscopy. The structure and dimensions of the filament and the hook-basal body, as revealed by electron microscopy, resemble those of H+-dependent flagella from gram-positive bacteria. Intramembrane particle rings were present at the cell pole in freeze-fractured A. woodii cells, which might correspond to the mot complex. PMID:9742948

  6. Isolation of Acetobacterium sp. strain AG, which reductively debrominates octa- and pentabrominated diphenyl ether technical mixtures.

    PubMed

    Ding, Chang; Chow, Wai Ling; He, Jianzhong

    2013-02-01

    Polybrominated diphenyl ethers (PBDEs) are a class of environmental pollutants that have been classified as persistent organic pollutants since 2009. In this study, a sediment-free enrichment culture (culture G) was found to reductively debrominate octa- and penta-BDE technical mixtures to less-brominated congeners (tetra-, tri-, and di-BDEs) via a para-dominant debromination pattern for the former and a strict para debromination pattern for the latter. Culture G could debrominate 96% of 280 nM PBDEs in an octa-BDE mixture to primarily tetra-BDEs in 21 weeks. Continuous transferring of culture G with octa-/penta-BDEs dissolved in n-nonane or trichloroethene (TCE) yielded two strains (Acetobacterium sp. strain AG and Dehalococcoides sp. strain DG) that retained debromination capabilities. In the presence of lactate but without TCE, strain AG could cometabolically debrominate 75% of 275 nM PBDEs in a penta-BDE mixture in 33 days. Strain AG shows 99% identity to its closest relative, Acetobacterium malicum. In contrast to strain AG, strain DG debrominated PBDEs only in the presence of TCE. In addition, 18 out of 19 unknown PBDE debromination products were successfully identified from octa- and penta-BDE mixtures and revealed, for the first time, a comprehensive microbial PBDE debromination pathway. As an acetogenic autotroph that rapidly debrominates octa- and penta-BDE technical mixtures, Acetobacterium sp. strain AG adds to the still-limited understanding of PBDE debromination by microorganisms. PMID:23204415

  7. Transfer and expression of the tetracycline resistance transposon Tn925 in Acetobacterium woodii.

    PubMed

    Strätz, M; Gottschalk, G; Dürre, P

    1990-03-01

    The Enterococcus faecalis conjugative plasmid pCF10 was used to introduce Tn925 into Acetobacterium woodii by filter mating. Tetracycline resistance was transferred at frequencies of about 10(-6) per donor, but no plasmid DNA was found in the transconjugants. DNA hybridization analyses of HindIII-digested chromosomal DNA demonstrated the insertion of Tn925 at a variety of locations, whereas wild type DNA showed no hybridization at all. The transconjugants were used as donor in mating experiments with tetracycline-sensitive Bacillus subtilis. Transfer of tetracycline resistance was observed at frequencies of 10(-8) per recipient. PMID:2158923

  8. Anaerobic biodegradation of methyl esters by Acetobacterium woodii and Eubacterium limosum.

    PubMed

    Liu, S; Suflita, J M

    1994-09-01

    The ability of Acetobacterium woodii and Eubacterium limosum to degrade methyl esters of acetate, propionate, butyrate, and isobutyrate was examined under growing and resting-cell conditions. Both bacteria hydrolyzed the esters to the corresponding carboxylates and methanol under either condition. Methanol was further oxidized to formate under growing but not resting conditions. Unlike the metabolism of phenylmethylethers, no H2 requirement was evident for ester biotransformation. The hydrolysis of methyl carboxylates is thermodynamically favorable under standard conditions and the mixotrophic metabolism of ester/CO2 allowed for bacterial growth. These results suggest that the degradation of methyl carboxylates may be a heretofore unrecognized nutritional option for acetogenic bacteria. PMID:7765371

  9. A sodium-stimulated ATP synthase in the acetogenic bacterium Acetobacterium woodii.

    PubMed

    Heise, R; Reidlinger, J; Müller, V; Gottschalk, G

    1991-12-16

    Experiments with resting cells of Acetobacterium woodii were performed to elucidate the coupling ion used by the ATP synthase. A. woodii synthesized ATP in response to an artificial delta pH, indicating the presence of a proton-translocating ATPase. On the other hand, a delta pNa, as well as a proton diffusion potential, could serve as a driving force for ATP synthesis with the latter strictly dependent on Na+. These results are indicative for the presence of a Na(+)-translocating ATP synthase in A. woodii. PMID:1837273

  10. Tetrahydrofolate enzyme levels in Acetobacterium woodii and their implication in the synthesis of acetate from CO2.

    PubMed Central

    Tanner, R S; Wolfe, R S; Ljungdahl, L G

    1978-01-01

    Acetate synthesis from CO2 by Acetobacterium woodii may occur as in homoacetate-fermenting clostridia, as indicated by high levels of enzymes of the tetrahydrofolate pathway and by pyruvate-dependent formation of acetate from methyl-B12 and methyltetrahydrofolate. PMID:659361

  11. Tetrahydrofolate enzyme levels in Acetobacterium woodii and their implication in the synthesis of acetate from CO2.

    PubMed

    Tanner, R S; Wolfe, R S; Ljungdahl, L G

    1978-05-01

    Acetate synthesis from CO2 by Acetobacterium woodii may occur as in homoacetate-fermenting clostridia, as indicated by high levels of enzymes of the tetrahydrofolate pathway and by pyruvate-dependent formation of acetate from methyl-B12 and methyltetrahydrofolate. PMID:659361

  12. Nonacetogenic Growth of the Acetogen Acetobacterium woodii on 1,2-Propanediol

    PubMed Central

    Schuchmann, Kai; Schmidt, Silke; Martinez Lopez, Antonio; Kaberline, Christina; Kuhns, Martin; Lorenzen, Wolfram; Bode, Helge B.; Joos, Friederike

    2014-01-01

    Acetogenic bacteria can grow by the oxidation of various substrates coupled to the reduction of CO2 in the Wood-Ljungdahl pathway. Here, we show that growth of the acetogen Acetobacterium woodii on 1,2-propanediol (1,2-PD) as the sole carbon and energy source is independent of acetogenesis. Enzymatic measurements and metabolite analysis revealed that 1,2-PD is dehydrated to propionaldehyde, which is further oxidized to propionyl coenzyme A (propionyl-CoA) with concomitant reduction of NAD. NADH is reoxidized by reducing propionaldehyde to propanol. The potential gene cluster coding for the responsible enzymes includes genes coding for shell proteins of bacterial microcompartments. Electron microscopy revealed the presence of microcompartments as well as storage granules in cells grown on 1,2-PD. Gene clusters coding for the 1,2-PD pathway can be found in other acetogens as well, but the distribution shows no relation to the phylogeny of the organisms. PMID:25384483

  13. Electron microscopic investigation of the hydrogen-oxidizing acetate-forming anaerobic bacterium Acetobacterium woodii.

    PubMed

    Mayer, F; Lurz, R; Schoberth, S

    1977-11-18

    Acetobacterium woodii is a Gram-positive anaerobic nonsporeforming bacterium able to grow on H2 and CO2 as sole sources of energy. The product of fermentation is acetic acid. Fine structural analysis showed rod-shaped flagellated cells, and coccoid cells without flagella arranged predominantly in pairs and chains. The cell wall was found to be composed of three layers. The cell surface exhibited a periodic array of particles consisting of subunits. The cytoplasmic membrane showed particles either in random distribution or in a hexagonal pattern. Intracytoplasmic membranes were rarely observed, whereas inclusion bodies of varying shapes, predominantly in an uncommon disc-shape, could frequently be observed. Their content was dissolved in ultrathin sections indicating hydrophobic nature. PMID:596994

  14. Methane formation from fructose by syntrophic associations of Acetobacterium woodii and different strains of methanogens.

    PubMed

    Winter, J U; Wolfe, R S

    1980-01-01

    When Acetobacterium woodii was co-cultured in continuous or in stationary culture with Methanobacterium strain AZ, fructose instead of being converted to 3 mol of acetate was converted to 2 mol of acetate and 1 mol each of carbon dioxide and methane, showing that interspecies hydrogen transfer occurred. In continuous culture the organisms formed a close physical association in clumps; the doubling time for each organism was 6 h at 33 degrees C. Methane mainly was derived from carbon positions 3 and 4 of the sugar, but other carbons also yielded methane; this was shown to be due to carbon dioxide-acetate exchange reactions by A. woodii in a manner similar to that carried out by Clostridium thermoaceticum. Four other methanogens, Methanobacterium M.o.H. and M.o.H. G, Methanobacterium formicicum, and Methanosarcina barkeri (not acetate-adapted) also produced similar results, when co-cultured with A. woodii. PMID:6769417

  15. Plasmid Transfer into the Homoacetogen Acetobacterium woodii by Electroporation and Conjugation.

    PubMed

    Strätz, M; Sauer, U; Kuhn, A; Dürre, P

    1994-03-01

    Shuttle vectors (pMS3 and pMS4) which replicated in Escherichia coli and in gram-positive Acetobacterium woodii were constructed by ligating the replication origin of plasmid pAMbeta1 with the E. coli cloning vector pUC19 and the tetM gene of streptococcal transposon Tn916. Electrotransformation of A. woodii was achieved at frequencies of 4.5 x 10 transformants per mug of plasmid DNA. For conjugal plasmid transfer, the mobilizable shuttle vector pKV12 was constructed by cloning the tetM gene into pAT187. Mating of E. coli containing pKV12 with A. woodii resulted in transfer frequencies of 3 x 10 to 7 x 10 per donor or recipient. PMID:16349209

  16. Genetic, immunological and biochemical evidence for a Rnf complex in the acetogen Acetobacterium woodii.

    PubMed

    Biegel, Eva; Schmidt, Silke; Müller, Volker

    2009-06-01

    Acetogenic bacteria grow by the oxidation of various substrates coupled to the reduction of carbon dioxide (acetogenesis) or other electron acceptors but the mechanisms of energy conservation are still enigmatic. Here, we report the presence of a rnf gene cluster rnfCDGEAB in Acetobacterium woodii that is speculated to encode a novel, energy-conserving ferredoxin:NAD(+)-oxidoreductase complex composed of at least six different subunits. Transcriptional analysis revealed that the genes constitute an operon. RnfC and RnfG were heterologously produced and antibodies were generated. Western blot analyses demonstrated that these subunits were produced and are associated with the cytoplasmic membrane. The subunits were present in cells respiring with either carbon dioxide or caffeate. A preparation with NADH dehydrogenase activity was obtained from detergent solubilized membranes that contained RnfC and RnfG. PMID:19222539

  17. Nonacetogenic growth of the acetogen Acetobacterium woodii on 1,2-propanediol.

    PubMed

    Schuchmann, Kai; Schmidt, Silke; Martinez Lopez, Antonio; Kaberline, Christina; Kuhns, Martin; Lorenzen, Wolfram; Bode, Helge B; Joos, Friederike; Müller, Volker

    2015-01-01

    Acetogenic bacteria can grow by the oxidation of various substrates coupled to the reduction of CO2 in the Wood-Ljungdahl pathway. Here, we show that growth of the acetogen Acetobacterium woodii on 1,2-propanediol (1,2-PD) as the sole carbon and energy source is independent of acetogenesis. Enzymatic measurements and metabolite analysis revealed that 1,2-PD is dehydrated to propionaldehyde, which is further oxidized to propionyl coenzyme A (propionyl-CoA) with concomitant reduction of NAD. NADH is reoxidized by reducing propionaldehyde to propanol. The potential gene cluster coding for the responsible enzymes includes genes coding for shell proteins of bacterial microcompartments. Electron microscopy revealed the presence of microcompartments as well as storage granules in cells grown on 1,2-PD. Gene clusters coding for the 1,2-PD pathway can be found in other acetogens as well, but the distribution shows no relation to the phylogeny of the organisms. PMID:25384483

  18. Heterotrimeric NADH-Oxidizing Methylenetetrahydrofolate Reductase from the Acetogenic Bacterium Acetobacterium woodii

    PubMed Central

    Bertsch, Johannes; Öppinger, Christian; Hess, Verena; Langer, Julian D.

    2015-01-01

    ABSTRACT The methylenetetrahydrofolate reductase (MTHFR) of acetogenic bacteria catalyzes the reduction of methylene-THF, which is highly exergonic with NADH as the reductant. Therefore, the enzyme was suggested to be involved in energy conservation by reducing ferredoxin via electron bifurcation, followed by Na+ translocation by the Rnf complex. The enzyme was purified from Acetobacterium woodii and shown to have an unprecedented subunit composition containing the three subunits RnfC2, MetF, and MetV. The stable complex contained 2 flavin mononucleotides (FMN), 23.5 ± 1.2 Fe and 24.5 ± 1.5 S, which fits well to the predicted six [4Fe4S] clusters in MetV and RnfC2. The enzyme catalyzed NADH:methylviologen and NADH:ferricyanide oxidoreductase activity but also methylene-tetrahydrofolate (THF) reduction with NADH as the reductant. The NADH:methylene-THF reductase activity was high (248 U/mg) and not stimulated by ferredoxin. Furthermore, reduction of ferredoxin, alone or in the presence of methylene-THF and NADH, was never observed. MetF or MetVF was not able to catalyze the methylene-THF-dependent oxidation of NADH, but MetVF could reduce methylene-THF using methyl viologen as the electron donor. The purified MTHFR complex did not catalyze the reverse reaction, the endergonic oxidation of methyl-THF with NAD+ as the acceptor, and this reaction could not be driven by reduced ferredoxin. However, addition of protein fractions made the oxidation of methyl-THF to methylene-THF coupled to NAD+ reduction possible. Our data demonstrate that the MTHFR of A. woodii catalyzes methylene-THF reduction according to the following reaction: NADH + methylene-THF → methyl-THF + NAD+. The differences in the subunit compositions of MTHFRs of bacteria are discussed in the light of their different functions. IMPORTANCE Energy conservation in the acetogenic bacterium Acetobacterium woodii involves ferredoxin reduction followed by a chemiosmotic mechanism involving Na

  19. Transformation of tetrachloromethane to dichloromethane and carbon dioxide by Acetobacterium woodii

    SciTech Connect

    Egli, C.; Tschan, T.; Scholtz, R.; Cook, A.M.; Leisinger, T. )

    1988-11-01

    Five anaerobic bacteria were tested for their abilities to transform tetrachloromethane so that information about enzymes involved in reductive dehalogenations of polychloromethanes could be obtained. Cultures of the sulfate reducer Desulfobacterium autotrophicum transformed some 80 {mu}M tetrachloromethane to trichloromethane and a small amount of dichloromethane in 18 days under conditions of heterotrophic growth. The acetogens Acetobacterium woodii and Clostridium thermoaceticum in fructose-salts and glucose-salts media, respectively, degraded some 80 {mu}M tetrachloromethane completely within 3 days. Trichloromethane accumulated as a transient intermediate, but the only chlorinated methanes recovered at the end of the incubation were 8 {mu}M dichloromethane and traces of chloromethane. Desulfobacter hydrogenophilus and an autotrophic, nitrate-reducing bacterium were unable to transform tetrachloromethane. Reduction of chlorinated methanes was thus observed only in the organisms with the acetyl-coenzyme A pathway. Experiments with ({sup 14}C)tetrachloromethane were done to determine the fate of this compound in the acetogen A. woodii. Radioactivity in an 11-day heterotrophic culture was largely (67%) recovered in CO{sub 2}, acetate, pyruvate, and cell material. In experiments with cell suspensions to which ({sup 14}C)tetrachloromethane was added, {sup 14}CO{sub 2} appeared within 20 s as the major transformation product. A. woodii thus catalyzes reductive dechlorinations and transforms tetrachloromethane to CO{sub 2} by a series of unknown reactions.

  20. Role of carbon monoxide dehydrogenase in acetate synthesis by the acetogenic bacterium, Acetobacterium woodii.

    PubMed

    Shanmugasundaram, T; Ragsdale, S W; Wood, H G

    1988-07-01

    Carbon monoxide dehydrogenase (CODH) plays a key role in acetate synthesis by the acetogenic bacterium, Clostridium thermoaceticum. Acetobacterium woodii, like C. thermoaceticum contains high levels of CODH. In this work we show that crude extracts of A. woodii synthesize acetate from methyl tetrahydrofolate or methyl iodide, carbon monoxide and coenzyme A (CoA). The purified CODH from A. woodii catalyzes an exchange reaction between CO and the carbonyl group of acetyl-CoA even faster than the C. thermoaceticum enzyme, indicating the CODH of A. woodii, like that of C. thermoaceticum is an acetyl-CoA synthetase. Fluorescence and EPR studies further support this postulate by demonstrating that CODH binds CoA near the CO binding site involving a tryptophan residue. The UV absorption spectra and the amino acid compositions of A. woodii and C. thermoaceticum CODHs are very similar. Evidence is presented using purified enzymes from A. woodii that the synthesis of acetyl-CoA occurs by a pathway similar to that utilized by C. thermoaceticum. PMID:2855585

  1. A Na+-translocating pyrophosphatase in the acetogenic bacterium Acetobacterium woodii.

    PubMed

    Biegel, Eva; Müller, Volker

    2011-02-25

    The anaerobic acetogenic bacterium Acetobacterium woodii employs a novel type of Na(+)-motive anaerobic respiration, caffeate respiration. However, this respiration is at the thermodynamic limit of energy conservation, and even worse, in the first step, caffeate is activated by caffeyl-CoA synthetase, which hydrolyzes ATP to AMP and pyrophosphate. Here, we have addressed whether or not the energy stored in the anhydride bond of pyrophosphate is conserved by A. woodii. Inverted membrane vesicles of A. woodii have a membrane-bound pyrophosphatase that catalyzes pyrophosphate hydrolysis at a rate of 70-120 milliunits/mg of protein. Pyrophosphatase activity was dependent on the divalent cation Mg(2+). In addition, activity was strictly dependent on Na(+) with a K(m) of 1.1 mM. Hydrolysis of pyrophosphate was accompanied by (22)Na(+) transport into the lumen of the inverted membrane vesicles. Inhibitor studies revealed that (22)Na(+) transport was primary and electrogenic. Next to the Na(+)-motive ferredoxin:NAD(+) oxidoreductase (Fno or Rnf), the Na(+)-pyrophosphatase is the second primary Na(+)-translocating enzyme in A. woodii. PMID:21173152

  2. Anaerobic O-demethylation of phenylmethylethers. [und Acetobacterium woodii :a3

    SciTech Connect

    Frazer, A.C.; Young, L.Y.

    1991-08-01

    Assay of O-demethylation in cell-free extracts of Acetobacterium woodii: we have shown that THF and ATP are necessary for enzyme activity and thus are probably reactants; apparent Km values were 0.65 mM for the methoxylated substrate, 0.27 mM for ATP, and 0.17 mM for DL-THF. The enzyme activity is present in the cytosol, rather than being membrane bound, and is sensitive to oxygen. There is evidence to suggest that the enzyme system involves more than one protein component. Studies using suspensions of whole cells, suggest that there are several inducible AOD systems with distinguishable substrate specificities in A. woodii. A similar phenomenon has previously been suggested for the related acetogen, Eubacterium limosum. We have developed a system for obtaining mutants that are deficient in O-demethylation (AOD{sup {minus}}) in E. limosum, by using transposon mutagenesis with Tn916. In an ancillary study, A. woodii and E. limosum, were compared with respect to their capacity to O-demethylate guaiacol and chloroguaiacols. 8 refs., 1 fig., 1 tab.

  3. Reaction engineering analysis of hydrogenotrophic production of acetic acid by Acetobacterium woodii.

    PubMed

    Demler, Martin; Weuster-Botz, Dirk

    2011-02-01

    Great interest has emerged in biological CO₂-fixing processes in the context of current climate change discussions. One example for such a process is the hydrogenotrophic production of acetic acid by anaerobic microorganisms. Acetogenic microorganisms make use of carbon dioxide in the presence of hydrogen to produce acetic acid and biomass. In order to establish a process for the hydrogenotrophic production of acetic acid, the formation of acetate by Acetobacterium woodii was studied in a batch-operated stirred-tank bioreactor at different hydrogen partial pressures (pH₂) in the gas phase. The volumetric productivity of the batch processes increased with increasing hydrogen partial pressure. A maximum of the volumetric productivity of 7.4 g(acetate) L⁻¹ day⁻¹ was measured at a pH₂ of 1,700 mbar. At this pH(2) a final acetate concentration of 44 g L⁻¹ was measured after a process time of 11 days, if the pH was controlled at pH 7.0 (average cell density of 1.1 g L⁻¹ cell dry weight). The maximum cell specific actetate productivity was 6.9 g(acetate) g(cdw)⁻¹ day⁻¹ under hydrogenotrophic conditions. PMID:20830677

  4. Transformation of tetrachloromethane to dichloromethane and carbon dioxide by Acetobacterium woodii.

    PubMed

    Egli, C; Tschan, T; Scholtz, R; Cook, A M; Leisinger, T

    1988-11-01

    Five anaerobic bacteria were tested for their abilities to transform tetrachloromethane so that information about enzymes involved in reductive dehalogenations of polychloromethanes could be obtained. Cultures of the sulfate reducer Desulfobacterium autotrophicum transformed some 80 microM tetrachloromethane to trichloromethane and a small amount of dichloromethane in 18 days under conditions of heterotrophic growth. The acetogens Acetobacterium woodii and Clostridium thermoaceticum in fructose-salts and glucose-salts media, respectively, degraded some 80 microM tetrachloromethane completely within 3 days. Trichloromethane accumulated as a transient intermediate, but the only chlorinated methanes recovered at the end of the incubation were 8 microM dichloromethane and traces of chloromethane. Desulfobacter hydrogenophilus and an autotrophic, nitrate-reducing bacterium were unable to transform tetrachloromethane. Reduction of chlorinated methanes was thus observed only in the organisms with the acetyl-coenzyme A pathway. Experiments with [14C]tetrachloromethane were done to determine the fate of this compound in the acetogen A. woodii. Radioactivity in an 11-day heterotrophic culture was largely (67%) recovered in CO2, acetate, pyruvate, and cell material. In experiments with cell suspensions to which [14C]tetrachloromethane was added, 14CO2 appeared within 20 s as the major transformation product. A. woodii thus catalyzes reductive dechlorinations and transforms tetrachloromethane to CO2 by a series of unknown reactions. PMID:3145712

  5. Sodium dependence of acetate formation by the acetogenic bacterium Acetobacterium woodii.

    PubMed

    Heise, R; Müller, V; Gottschalk, G

    1989-10-01

    Growth of Acetobacterium woodii on fructose was stimulated by Na+; this stimulation was paralleled by a shift of the acetate-fructose ratio from 2.1 to 2.7. Growth on H2-CO2 or on methanol plus CO2 was strictly dependent on the presence of sodium ions in the medium. Acetate formation from formaldehyde plus H2-CO by resting cells required Na+, but from methanol plus H2-CO did not. This is analogous to H2-CO2 reduction to methane by Methanosarcina barkeri, which involves a sodium pump (V. Müller, C. Winner, and G. Gottschalk, Eur. J. Biochem. 178:519-525, 1988). This suggests that the reduction of methylenetetrahydrofolate to methyltetrahydrofolate is the Na+-requiring reaction. A sodium gradient (Na+ out/Na+ in = 32, delta pNa = -91 mV) was built up when resting cells of A. woodii were incubated under H2-CO2. Acetogenesis was inhibited when the delta pNa was dissipated by monensin. PMID:2507527

  6. Presence of a sodium-translocating ATPase in membrane vesicles of the homoacetogenic bacterium Acetobacterium woodii.

    PubMed

    Heise, R; Müller, V; Gottschalk, G

    1992-06-01

    Inverted membrane vesicles of the homoacetogenic bacterium Acetobacterium woodii catalyzed the hydrolysis of ATP with a rate of 100-150 nmol.min-1.mg protein-1. The ATPase was stimulated 1.4-1.6-fold by NaCl and inhibited by N,N'-dicyclohexylcarbodiimide tributyltin or azide. The degree of inhibition caused by F0-directed but not F1-directed inhibitors was affected by the Na+ concentration in the medium. These experiments indicated the presence of a sodium-translocating ATPase. This was verified by transport studies. Upon addition of ATP to inverted vesicles, 22Na+ was actively transported into the intravesicular space up to a 24-fold accumulation. Na+ transport was inhibited by the sodium ionophore N,N,N',N',-tetracyclohexyl-1,2-phenyl-enedioxydiacetamide but stimulated by valinomycin with potassium whereas the protonophore 3,5,-di-tert-butyl-4-hydroxybenzylidenemalonitrile was without effect. N,N'-dicyclohexylcarbodiimide and tributyltin inhibited 22Na+ transport. These experiments are in accordance with a primary electrogenic Na+ transport as catalyzed by a F1F0-ATPase. PMID:1534543

  7. Continuous gas fermentation by Acetobacterium woodii in a submerged membrane reactor with full cell retention.

    PubMed

    Kantzow, Christina; Mayer, Alexander; Weuster-Botz, Dirk

    2015-10-20

    Acetogenic bacteria like Acetobacterium woodii represent an ancient group of anaerobic microorganisms which use hydrogen and carbon dioxide to produce acetate. Cell concentrations and space-time yields are usually low in gas fermentations. A standard stirred‑tank bioreactor with continuous gas supply was equipped with a customized submerged microfiltration unit. A. woodii showed similar growth behavior with an initial maximal growth rate of 1.2 d(-1) in continuous gas fermentations with full cell retention and varying dilution rates. A steady increase of cell mass concentrations was observed with the highest biomass formation at the highest dilution rate. By contrast the final acetate concentrations were lowest at the highest dilution rate. The highest final acetate space-time yield of 148 g l(-1) d(-1) was measured at the highest dilution rate (increase by factor 8 compared to a standard batch process or by factor 37 compared to published data). The highest reported cell concentration of A. woodii in gas fermentations of nearly 14 g l(-1) cell dry weight was achieved in the submerged membrane bioreactor with increased yeast extract concentrations in the feed medium. Product inhibition was observed when acetate concentrations exceeded 8-12 g l(-1) causing a steady decrease in cell mass specific acetate production rates. PMID:26239230

  8. Selective enhancement of autotrophic acetate production with genetically modified Acetobacterium woodii.

    PubMed

    Straub, Melanie; Demler, Martin; Weuster-Botz, Dirk; Dürre, Peter

    2014-05-20

    Great interest has emerged in the recent past towards the potential of autotrophic acetogenic bacteria for the sustainable production of fuels and chemicals. This group of microorganisms possesses an ancient pathway for the fixation of carbon dioxide in the presence of hydrogen, making them highly attractive for the utilization of gas mixtures as a cheap and abundant carbon and energy source. As more and more genome sequence data of acetogens becomes available, the genetic tools are being developed concomitantly. Here, we demonstrate for the first time the genetic modification of the well-characterized acetogen Acetobacterium woodii. This microorganism selectively produces acetate under autotrophic conditions, but seems to be limited at high acetate concentrations. To increase the carbon flow through the Wood-Ljungdahl pathway and therefore increase the efficiency of CO2 fixation, genes of enzyme groups of this pathway were selectively overexpressed (the four THF-dependent enzymes for the processing of formate as well as phosphotransacetylase and acetate kinase to enhance an ATP-generation step). Acetate production with genetically modified strains was increased in a batch process under pH-controlled reaction conditions in a stirred-tank reactor with continuous sparging of H2 and CO2. Final acetate concentrations of more than 50gL(-1) acetate were thus measured with the recombinant strains at low cell concentrations of 1.5-2gL(-1) dry cell mass in less than four days under autotrophic conditions. PMID:24637370

  9. Transformation of tetrachloromethane to dichloromethane and carbon dioxide by Acetobacterium woodii.

    PubMed Central

    Egli, C; Tschan, T; Scholtz, R; Cook, A M; Leisinger, T

    1988-01-01

    Five anaerobic bacteria were tested for their abilities to transform tetrachloromethane so that information about enzymes involved in reductive dehalogenations of polychloromethanes could be obtained. Cultures of the sulfate reducer Desulfobacterium autotrophicum transformed some 80 microM tetrachloromethane to trichloromethane and a small amount of dichloromethane in 18 days under conditions of heterotrophic growth. The acetogens Acetobacterium woodii and Clostridium thermoaceticum in fructose-salts and glucose-salts media, respectively, degraded some 80 microM tetrachloromethane completely within 3 days. Trichloromethane accumulated as a transient intermediate, but the only chlorinated methanes recovered at the end of the incubation were 8 microM dichloromethane and traces of chloromethane. Desulfobacter hydrogenophilus and an autotrophic, nitrate-reducing bacterium were unable to transform tetrachloromethane. Reduction of chlorinated methanes was thus observed only in the organisms with the acetyl-coenzyme A pathway. Experiments with [14C]tetrachloromethane were done to determine the fate of this compound in the acetogen A. woodii. Radioactivity in an 11-day heterotrophic culture was largely (67%) recovered in CO2, acetate, pyruvate, and cell material. In experiments with cell suspensions to which [14C]tetrachloromethane was added, 14CO2 appeared within 20 s as the major transformation product. A. woodii thus catalyzes reductive dechlorinations and transforms tetrachloromethane to CO2 by a series of unknown reactions. PMID:3145712

  10. Complete degradation of carbohydrate to carbon dioxide and methane by syntrophic cultures of Acetobacterium woodii and Methanosarcina barkeri.

    PubMed

    Winter, J; Wolfe, R S

    1979-04-01

    Methanosarcina barkeri (strain MS) grew and converted acetate to CO2 and methane after an adaption period of 20 days. Growth and metabolism were rapid with gas production being comparable to that of cells grown on H2 and CO2. After an intermediary growth cycle under a H2 and CO2 atmosphere acetate-adapted cells were capable of growth on acetate with formation of methane and CO2. When acetate-adapted Methanosarcina barkeri was co-cultured with Acetobacterium woodii on fructose or glucose as substrate, a complete conversion of the carbohydrate to gases (CO2 and CH4) was observed. PMID:464732

  11. Enhanced biotransformation of carbon tetrachloride by Acetobacterium woodii upon addition of hydroxocobalamin and fructose

    SciTech Connect

    Hashsham, S.A.; Freedman, D.L.

    1999-10-01

    The objective of this study was to evaluate the effect of hydroxocobalamin (OH-Cbl) on transformation of high concentrations of carbon tetrachloride (CT) by Acetobacterium woodii. Complete transformation of 470 {micro}M CT was achieved by A. woodii within 2.5 days, when 10 {micro}M OH-Cbl was added along with 25.2 mM fructose. This was approximately 30 times faster than A. woodii cultures and medium that did not receive OH-Cbl and 5 times faster than those controls that did receive OH-Cbl, but either live A. woodii or fructose was missing. CT transformation in treatments with only OH-Cbl was indicative of the important contribution of nonenzymatic reactions. Besides increasing the rate of CT transformation, addition of fructose and OH-Cbl to live cultures increased the percentage of [{sup 14}C]CT transformed to {sup 14}CO{sub 2} and {sup 14}C-labeled soluble materials, while decreasing the percentage of CT reduced to chloroform and abiotically transformed to carbon disulfide. {sup 14}CS{sub 2} represented more than 35% of the [{sup 14}C]CT in the presence of reduced medium and OH-Cbl. Conversion of CT to CO was a predominant pathway in formation of CO{sub 2} in the presence of live cells and added fructose and OH-Cbl. These results indicate that the rate and distribution of products during cometabolic transformation of CT by A. woodii can be improved by the addition of fructose and OH-Cbl.

  12. Effects of hydrogen partial pressure on autotrophic growth and product formation of Acetobacterium woodii.

    PubMed

    Kantzow, Christina; Weuster-Botz, Dirk

    2016-08-01

    Low aqueous solubility of the gases for autotrophic fermentations (e.g., hydrogen gas) results in low productivities in bioreactors. A frequently suggested approach to overcome mass transfer limitation is to increase the solubility of the limiting gas in the reaction medium by increasing the partial pressure in the gas phase. An increased inlet hydrogen partial pressure of up to 2.1 bar (total pressure of 3.5 bar) was applied for the autotrophic conversion of hydrogen and carbon dioxide with Acetobacterium woodii in a batch-operated stirred-tank bioreactor with continuous gas supply. Compared to the autotrophic batch process with an inlet hydrogen partial pressure of 0.4 bar (total pressure of 1.0 bar) the final acetate concentration after 3.1 days was reduced to 50 % (29.2 g L(-1) compared to 59.3 g L(-1)), but the final formate concentration was increased by a factor of 18 (7.3 g L(-1) compared to 0.4 g L(-1)). Applying recombinant A. woodii strains overexpressing either genes for enzymes in the methyl branch of the Wood-Ljungdahl pathway or the genes phosphotransacetylase and acetate kinase at an inlet hydrogen partial pressure of 1.4 bar reduced the final formate concentration by up to 40 % and increased the final dry cell mass and acetate concentrations compared to the wild type strain. Solely the overexpression of the two genes for ATP regeneration at the end of the Wood-Ljungdahl pathway resulted in an initial switch off of formate production at increased hydrogen partial pressure until the maximum of the hydrogen uptake rate was reached. PMID:27059835

  13. Purification and properties of NAD-dependent 5,10-methylenetetrahydrofolate dehydrogenase from Acetobacterium woodii.

    PubMed

    Ragsdale, S W; Ljungdahl, L G

    1984-03-25

    An NAD-dependent 5,10-methylenetetrahydrofolate dehydrogenase has been purified to homogeneity from autotrophically and heterotrophically grown cells of Acetobacterium woodii. The enzymes from the differently grown cells were indistinguishable by gel filtration and sodium dodecyl sulfate electrophoresis and have a final specific activity of 670 units mg-1. The enzyme is oxygen-labile; therefore, it was isolated under anaerobic conditions in the presence of dithiothreitol. The oxidized enzyme can be reactivated with 5 mM dithiothreitol, the half-time of activation being 19 min. The forward and reverse reaction initial velocity kinetics was studied and the enzyme was found to follow a substituted (ping-pong) reaction mechanism. With this model, the Km values for NAD and 5,10-methylenetetrahydrofolate are 4.0 and 0.26 mM, while for NADH and 5,10-methenyltetrahydrofolate, they are 2.0 and 1.0 mM, respectively. The equilibrium constant at pH 6.7, determined by the Haldane relationship, is approximately equal to 2.0, favoring the formation of NADH and 5,10-methenyltetrahydrofolate. The purified enzyme is a Mr = 55,000 dimer which lacks 10-formyltetrahydrofolate synthetase and 5,10-methenyltetrahydrofolate cyclohydrolase activities. At pH 6.7, the conversion of 5,10-methylenetetrahydrofolate to 5,10-methenyltetrahydrofolate occurs at a rate of 98,600 mol min-1 mol-1 of enzyme, while the reverse reaction occurs at a rate of 95,600 mol min-1 mol-1 of enzyme. PMID:6608524

  14. Additional characteristics of one-carbon-compound utilization by Eubacterium limosum and Acetobacterium woodii.

    PubMed

    Sharak Genthner, B R; Bryant, M P

    1987-03-01

    Growth characteristics of Eubacterium limosum and Acetobacterium woodii during one-carbon-compound utilization were investigated. E. limosum RF grew with formate as the sole energy source. Formate also replaced a requirement for CO2 during growth with methanol. Growth with methanol required either rumen fluid, yeast extract, or acetate, but their effects were not additive. Cultures were adapted to grow in concentrations of methanol of up to 494 mM. Growth occurred with methanol in the presence of elevated levels of Na+ (576 mM). The pH optima for growth with methanol, H2-CO2, and carbon monoxide were similar (7.0 to 7.2). Growth occurred with glucose at a pH of 4.7, but not at 4.0. The apparent Km values for methanol and hydrogen were 2.7 and 0.34 mM, respectively. The apparent Vmax values for methanol and hydrogen were 1.7 and 0.11 mumol/mg of protein X min-1, respectively. The Ks value for CO was estimated to be less than 75 microM. Cellular growth yields were 70.5, 7.1, 3.38, and 0.84 g (dry weight) per mol utilized for glucose, methanol, CO, and hydrogen (in H2-CO2), respectively. E. limosum was also able to grow with methoxylated aromatic compounds as energy sources. Glucose apparently repressed the ability of E. limosum to use methanol, hydrogen, or isoleucine but not CO. Growth with mixtures of methanol, H2, CO, or isoleucine was not diauxic. The results, especially the relatively high apparent Km values for H2 and methanol, may indicate why E. limosum does not usually compete with rumen methanogens for these energy sources.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3579266

  15. Enhanced biotransformation of carbon tetrachloride by Acetobacterium woodii upon addition of hydroxocobalamin and fructose.

    PubMed

    Hashsham, S A; Freedman, D L

    1999-10-01

    The objective of this study was to evaluate the effect of hydroxocobalamin (OH-Cbl) on transformation of high concentrations of carbon tetrachloride (CT) by Acetobacterium woodii (ATCC 29683). Complete transformation of 470 microM (72 mg/liter [aqueous]) CT was achieved by A. woodii within 2.5 days, when 10 microM OH-Cbl was added along with 25.2 mM fructose. This was approximately 30 times faster than A. woodii cultures (live or autoclaved) and medium that did not receive OH-Cbl and 5 times faster than those controls that did receive OH-Cbl, but either live A. woodii or fructose was missing. CT transformation in treatments with only OH-Cbl was indicative of the important contribution of nonenzymatic reactions. Besides increasing the rate of CT transformation, addition of fructose and OH-Cbl to live cultures increased the percentage of [(14)C]CT transformed to (14)CO(2) (up to 31%) and (14)C-labeled soluble materials (principally L-lactate and acetate), while decreasing the percentage of CT reduced to chloroform and abiotically transformed to carbon disulfide. (14)CS(2) represented more than 35% of the [(14)C]CT in the presence of reduced medium and OH-Cbl. Conversion of CT to CO was a predominant pathway in formation of CO(2) in the presence of live cells and added fructose and OH-Cbl. These results indicate that the rate and distribution of products during cometabolic transformation of CT by A. woodii can be improved by the addition of fructose and OH-Cbl. PMID:10508086

  16. Purification and properties of NAD-dependent 5,10-methylenetetrahydrofolate dehydrogenase from Acetobacterium woodii

    SciTech Connect

    Ragsdale, S.W.; Ljungdahl, L.G.

    1984-03-25

    An NAD-dependent 5,10-methylenetetrahydrofolate dehydrogenase has been purified to homogeneity from autotrophically and heterotrophically grown cells of Acetobacterium woodii. The enzymes from the differently grown cells were indistinguishable by gel filtration and sodium dodecyl sulfate electrophoresis and have a final specific activity of 670 units mg/sup -1/. The enzyme is oxygen-labile; therefore, it was isolated under anaerobic conditions in the presence of dithiothreitol. The oxidized enzyme can be reactivated with 5 mM dithiothreitol, the half-time of activation being 19 min. The forward and reverse reaction initial velocity kinetics was studied and the enzyme was found to follow a substituted reaction mechanism. With this model, the K/sub m/ values for NAD and 5,10-methylenetetrahydrofolate are 4.0 and 0.26 mM, while for NADH and 5,10-methenyltetrahydrofolate, they are 2.0 and 1.0 mM, respectively. The equilibrium constant at pH 6.7, determined by the Haldane relationship, is approximately equal to 2.0, favoring the formation of NADH and 5,10-methenyltetrahydrofolate. The purified enzyme is a M/sub r/ = 55,000 dimer which lacks 10-formyltetrahydrofolate synthetase and 5,10-methenyltetrahydrofolate cyclohydrolase activities. At pH 6.7, the conversion of 5,10-methylenetetrahydrofolate to 5,10-methenyltetrahydrofolate occurs at a rate of 98,600 mol min/sup -1/ mol/sup -1/ of enzyme, while the reverse reaction occurs at a rate of 95,600 mol min/sup -1/ mol/sup -1/ of enzyme.

  17. Purification of ATP synthase from Acetobacterium woodii and identification as a Na(+)-translocating F1F0-type enzyme.

    PubMed

    Reidlinger, J; Müller, V

    1994-07-01

    The ATPase of Acetobacterium woodii was purified after solubilization of membranes with Triton X-100 by poly(ethylene glycol) precipitation and gel filtration. The enzyme consists of at least six subunits of apparent molecular masses of 57, 52, 35, 19, 15 and 4.8 kDa, as determined by SDS/PAGE. The 52-kDa band is immunologically related to the F1F0-ATPase beta subunit of Escherichia coli. The enzyme is not inhibited by vanadate but is inhibited by nitrate, azide and N,N'-dicyclohexylcarbodiimide; the 4.8-kDa subunit specifically reacts with N,N'-dicyclohexyl[14C]carbodiimide, indicating that the enzyme is of the F1F0 type. The enzyme activity is dependent on MgATP (Km = 0.4), has a pH optimum of pH 7-9 and is stimulated by sulfite. ATP hydrolysis is strictly dependent on sodium ions with a Km for Na+ of 0.4 mM. The purified enzyme was reconstituted into liposomes. Upon addition of ATP, primary and electrogenic 22Na+ transport into the lumen of the proteoliposomes was determined. These experiments demonstrate that the ATPase of Acetobacterium woodii is a Na(+)-translocating F1F0-type ATPase. PMID:8033902

  18. Discovery of a ferredoxin:NAD+-oxidoreductase (Rnf) in Acetobacterium woodii: a novel potential coupling site in acetogens.

    PubMed

    Müller, Volker; Imkamp, Frank; Biegel, Eva; Schmidt, Silke; Dilling, Sabrina

    2008-03-01

    Acetogens use the Wood-Ljungdahl pathway for reduction of carbon dioxide to acetate. This pathway not only allows reoxidation of reducing equivalents during heterotrophic growth but also supports chemolithoautotrophic growth on H(2) + CO(2). The latter argues for this pathway being a source for net energy conservation, but the mechanism involved remains unknown. In addition to CO(2), acetogens can use alternative electron acceptors, such as nitrate or caffeate. Caffeate respiration in the model acetogen Acetobacterium woodii is coupled to energy conservation via a chemiosmotic mechanism, with Na(+) as coupling ion. The pathway and its bioenergetics were solved in some detail very recently. This review focuses on the regulation of caffeate respiration, describes the enyzmes involved, summarizes the evidence for a potential Na(+)-translocating ferredoxin:NAD(+)-oxidoreductase (Rnf complex) as a new coupling site, and hypothesizes on the role of this Rnf complex in the Wood-Ljungdahl pathway. PMID:18378592

  19. Sequence of subunit c of the Na(+)-translocating F1F0 ATPase of Acetobacterium woodii: proposal for determinants of Na+ specificity as revealed by sequence comparisons.

    PubMed

    Rahlfs, S; Müller, V

    1997-03-10

    A 3.2 kb EcoRI fragment carrying genes for Na(+)-F1F0 ATPase was cloned from chromosomal DNA of Acetobacterium woodii. DNA sequence analysis revealed the presence of an open reading frame which was identified by data base searches and comparison with the experimentally derived N-terminal amino acid sequence to code for subunit c of Na(+)-F1F0 ATPase. A comparison of the primary sequences of the two well established Na(+)-translocating F1F0 ATPases from Acetobacterium woodii and Propionigenium modestum with H(+)-translocating enzymes indicates the length of the C-terminus as well as specific residues located in the cytoplasmic membrane to be important for Na+ transport. PMID:9119076

  20. The molecular structure of the Na(+)-translocating F1F0-ATPase of Acetobacterium woodii, as revealed by electron microscopy, resembles that of H(+)-translocating ATPases.

    PubMed

    Reidlinger, J; Mayer, F; Müller, V

    1994-12-12

    The Na(+)-translocating F1F0-ATPase of Acetobacterium woodii was examined by electron microscopy. After reconstitution into proteoliposomes, knobs typical for the F1 domain were visible on the outside of the membrane. The F1-part of the isolated enzyme showed a hexagonal symmetry suggesting an alpha 3 beta 3 structure, and the F1F0 complex had molecular dimensions very similar to those of H(+)-translocating ATPases of E. coli, chloroplasts, and mitochondria. PMID:7988711

  1. Effect of molecular hydrogen and carbon dioxide on chemo-organotrophic growth of Acetobacterium woodii and Clostridium aceticum.

    PubMed

    Braun, K; Gottschalk, G

    1981-01-01

    During growth of Acetobacterium woodii on fructose, glucose or lactate in a medium containing less than 0.04% bicarbonate, molecular hydrogen was evolved up to 0.1 mol per mol of substrate. Under an H2-atmosphere growth of A. woodii with organic substrates was completely inhibited whereas under an H2/CO2-atmosphere rapid growth occurred. Under these conditions H2 + CO2 and the organic substrate were utilized simultaneously indicating that A. woodii was able to grow mixotrophically. Clostridium aceticum differed from A. woodii in that H2 was only evolved in the stationary phase, that the inhibition by H2 was observed at pH 8.5 but not at pH 7.5, anf that in the presence of fructose and H2 + CO2 only fructose was utilized. The hydrogenase activity of fructose-grown cells of C. aceticum amounted to only 12% of that of H2 + CO2-grown cells. With A. woodii a corresponding decrease of the activity of this enzyme was not observed. PMID:6783002

  2. Chemiosmotic energy conservation with Na(+) as the coupling ion during hydrogen-dependent caffeate reduction by Acetobacterium woodii.

    PubMed

    Imkamp, Frank; Müller, Volker

    2002-04-01

    Cell suspensions of Acetobacterium woodii prepared from cultures grown on fructose plus caffeate catalyzed caffeate reduction with electrons derived from molecular hydrogen. Hydrogen-dependent caffeate reduction was strictly Na(+) dependent with a K(m) for Na(+) of 0.38 mM; Li(+) could substitute for Na(+). The sodium ionophore ETH2120, but not protonophores, stimulated hydrogen-dependent caffeate reduction by 280%, indicating that caffeate reduction is coupled to the buildup of a membrane potential generated by primary Na(+) extrusion. Caffeate reduction was coupled to the synthesis of ATP, and again, ATP synthesis coupled to hydrogen-dependent caffeate reduction was strictly Na(+) dependent and abolished by ETH2120, but not by protonophores, indicating the involvement of a transmembrane Na(+) gradient in ATP synthesis. The ATPase inhibitor N,N'-dicyclohexylcarbodiimide (DCCD) abolished ATP synthesis, and at the same time, hydrogen-dependent caffeate reduction was inhibited. This inhibition could be relieved by ETH2120. These experiments are fully compatible with a chemiosmotic mechanism of ATP synthesis with Na(+) as the coupling ion during hydrogen-dependent caffeate reduction by A. woodii. PMID:11889102

  3. A low phosphorylation potential in the acetogen Acetobacterium woodii reflects its lifestyle at the thermodynamic edge of life.

    PubMed

    Spahn, Sebastian; Brandt, Karsten; Müller, Volker

    2015-08-01

    The anaerobic, acetogenic bacterium Acetobacterium woodii grows on hydrogen and carbon dioxide and uses the Wood-Ljungdahl pathway to fix carbon but also to synthesize ATP. The free energy change of acetogenesis from H2 + CO2 allows for synthesis of only a fraction of an ATP under environmental conditions, and A. woodii is clearly a paradigm for microbial life under extreme energy limitation. However, it was unknown how much energy is required to make ATP under these conditions. In the present study, we determined the phosphorylation potential in cells metabolizing three different acetogenic substrates. It accounts to 37.9 ± 1.3 kJ/mol ATP during acetogenesis from fructose, 32.1 ± 0.3 kJ/mol ATP during acetogenesis from H2 + CO2 and 30.2 ± 0.9 kJ/mol ATP during acetogenesis from CO, the lowest phosphorylation potential ever described. The physiological consequences in terms of energy conservation under extreme energy limitation are discussed. PMID:25820826

  4. The Ether-Cleaving Methyltransferase System of the Strict Anaerobe Acetobacterium dehalogenans: Analysis and Expression of the Encoding Genes▿

    PubMed Central

    Schilhabel, Anke; Studenik, Sandra; Vödisch, Martin; Kreher, Sandra; Schlott, Bernhard; Pierik, Antonio Y.; Diekert, Gabriele

    2009-01-01

    Anaerobic O-demethylases are inducible multicomponent enzymes which mediate the cleavage of the ether bond of phenyl methyl ethers and the transfer of the methyl group to tetrahydrofolate. The genes of all components (methyltransferases I and II, CP, and activating enzyme [AE]) of the vanillate- and veratrol-O-demethylases of Acetobacterium dehalogenans were sequenced and analyzed. In A. dehalogenans, the genes for methyltransferase I, CP, and methyltransferase II of both O-demethylases are clustered. The single-copy gene for AE is not included in the O-demethylase gene clusters. It was found that AE grouped with COG3894 proteins, the function of which was unknown so far. Genes encoding COG3894 proteins with 20 to 41% amino acid sequence identity with AE are present in numerous genomes of anaerobic microorganisms. Inspection of the domain structure and genetic context of these orthologs predicts that these are also reductive activases for corrinoid enzymes (RACEs), such as carbon monoxide dehydrogenase/acetyl coenzyme A synthases or anaerobic methyltransferases. The genes encoding the O-demethylase components were heterologously expressed with a C-terminal Strep-tag in Escherichia coli, and the recombinant proteins methyltransferase I, CP, and AE were characterized. Gel shift experiments showed that the AE comigrated with the CP. The formation of other protein complexes with the O-demethylase components was not observed under the conditions used. The results point to a strong interaction of the AE with the CP. This is the first report on the functional heterologous expression of acetogenic phenyl methyl ether-cleaving O-demethylases. PMID:19011025

  5. Isolation of carbon monoxide dehydrogenase from Acetobacterium woodii and comparison of its properties with those of the Clostridium thermoaceticum enzyme.

    PubMed

    Ragsdale, S W; Ljungdahl, L G; DerVartanian, D V

    1983-09-01

    An oxygen-labile carbon monoxide dehydrogenase was purified to at least 98% homogeneity from fructose-grown cells of Acetobacterium woodii. Gel filtration and electrophoresis experiments gave molecular weights of 480,000 and 153,000, respectively, of the active enzyme. The molecular weights for the subunits are 80,000 and 68,000; the subunits occur in equal proportion. The small subunit of the A. woodii enzyme differs in size from that of the Clostridium thermoaceticum enzyme; however, the large subunits are similar. The specific activity of the A. woodii enzyme, measured at 30 degrees C and pH 7.6, is 500 mumol of CO oxidized min-1 mg-1 with 20 mM methyl viologen as the electron acceptor. Analysis revealed (number per dimer) iron (9), acid-labile sulfide (12), nickel (1.4), and magnesium or zinc (1). This metal content is quite similar to that of the C. thermoaceticum enzyme (Ragsdale et al., J. Biol. Chem. 258:2364-2369, 1983). The nickel as well as the iron-sulfur clusters are redox-active, as was found for the C. thermoaceticum enzyme (Ragsdale et al., Biochem. Biophys. Res. Commun. 108:658-663, 1982). CO can reduce and CO2 can oxidize the iron-sulfur clusters. The enzyme is inhibited by cyanide, but CO2 in the presence of reduced methyl viologen or CO alone can reverse or prevent this inhibition. Several ferredoxins, flavodoxin, and rubredoxin and some artificial electron carriers were tested for their relative rates of reaction with the CO dehydrogenases from A. woodii, C. thermoaceticum, and Clostridium formicoaceticum. Rubredoxin was by far the most reactive acceptor and is proposed to be the primary natural electron carrier for the acetogenic CO dehydrogenases. PMID:6309745

  6. A caffeyl-coenzyme A synthetase initiates caffeate activation prior to caffeate reduction in the acetogenic bacterium Acetobacterium woodii.

    PubMed

    Hess, Verena; Vitt, Stella; Müller, Volker

    2011-02-01

    The anaerobic acetogenic bacterium Acetobacterium woodii couples the reduction of caffeate with electrons derived from hydrogen to the synthesis of ATP by a chemiosmotic mechanism using sodium ions as coupling ions, but the enzymes involved remain to be established. Previously, the electron transfer flavoproteins EtfA and EtfB were found to be involved in caffeate respiration. By inverse PCR, we identified three genes upstream of etfA and etfB: carA, carB, and carC. carA encodes a potential coenzyme A (CoA) transferase, carB an acyl-CoA synthetase, and carC an acyl-CoA dehydrogenase. carA, -B, and -C are located together with etfA/carE and etfB/carD on one polycistronic message, indicating that CarA, CarB, and CarC are also part of the caffeate respiration pathway. The genetic data suggest an initial ATP-dependent activation of caffeate by CarB. To prove the proposed function of CarB, the protein was overproduced in Escherichia coli, and the recombinant protein was purified. Purified CarB activates caffeate to caffeyl-CoA in an ATP- and CoA-dependent reaction. The enzyme has broad pH and temperature optima and requires K(+) for activity. In addition to caffeate, it can use ρ-coumarate, ferulate, and cinnamate as substrates, with 50, 15, and 9%, respectively, of the activity obtained with caffeate. Expression of the car operon is induced not only by caffeate, ρ-coumarate, ferulate, and cinnamate but also by sinapate. There is no induction by ρ-hydroxybenzoate or syringate. PMID:21131487

  7. Methanogenesis from sucrose by defined immobilized consortia. [Escherichia coli; Acetobacterium woodii; Desulfovibrio vulgaris; Methanosarcina barkeri; Methanobacterium formicicum

    SciTech Connect

    Jones, W.J.; Guyot, J.P.; Wolfe, R.S.

    1984-01-01

    A bacterial consortium capable of sucrose degradation primarily to CH/sub 4/ and CO/sub 2/ was constructed, with acetate as the key methanogenic precursor. In addition, the effect of agar immobilization on the activity of the consortium was determined. The primary fermentative organism, Escherichia coli, produced acetate, formate, H/sub 2/, and CO/sub 2/ (known substrates for methanogens), as well as ethanol and lactate, compounds that are not substrates for methanogens. Oxidation of the nonmethanogenic substrates, lactate and ethanol, to acetate was mediated by the addition of Acetobacterium woodii and Desulfovibrio vulgaris. The methanogenic stage was accomplished by the addition of the acetophilic methanogen Methanosarcina barkeri and the hydrogenophilic methanogen Methanobacterium formicicum. Results of studies with low substrate concentrations (0.05 to 0.2% (wt/vol)), a growth-limiting medium, and the five-component consortium indicated efficient conversion (40%) of sucrose carbon to CH/sub 4/. Significant decreases in yields of CH/sub 4/ and rates of CH/sub 4/ production were observed if any component of the consortium was omitted. Approximately 70% of the CH/sub 4/ generated occurred via acetate. Agar-immobilized cells of the consortium exhibited yields of CH/sub 4/ and rates of CH/sub 4/ production from sucrose similar to those of nonimmobilized cells. The rate of CH/sub 4/ production decreased by 25% when cysteine was omitted from reaction conditions and by 40% when the immobilized consortium was stored for 1 week at 4/sup 0/C.

  8. Caffeate respiration in the acetogenic bacterium Acetobacterium woodii: a coenzyme A loop saves energy for caffeate activation.

    PubMed

    Hess, Verena; González, José M; Parthasarathy, Anutthaman; Buckel, Wolfgang; Müller, Volker

    2013-03-01

    The anaerobic acetogenic bacterium Acetobacterium woodii couples reduction of caffeate with electrons derived from molecular hydrogen to the synthesis of ATP by a chemiosmotic mechanism with sodium ions as coupling ions. Caffeate is activated to caffeyl coenzyme A (caffeyl-CoA) prior to its reduction, and the caffeate reduction operon encodes an ATP-dependent caffeyl-CoA synthetase that is thought to catalyze the initial caffeate activation. The operon also encodes a potential CoA transferase, the product of carA, which was thought to be involved in subsequent ATP-independent caffeate activation. To prove the proposed function of carA, we overproduced its protein in Escherichia coli and then purified it. Purified CarA drives the formation of caffeyl-CoA from caffeate with hydrocaffeyl-CoA as the CoA donor. The dependence of the reaction on caffeate and hydrocaffeyl-CoA followed Michaelis-Menten kinetics, with apparent K(m) values of 75 ± 5 μM for caffeate and 8 ± 2 μM for hydrocaffeyl-CoA. The enzyme activity had broad ranges of pH and temperature optima. In addition to being able to use caffeate, CarA could use p-coumarate and ferulate but not cinnamate, sinapate, or p-hydroxybenzoate as a CoA acceptor. Neither acetyl-CoA nor butyryl-CoA served as the CoA donor for CarA. The enzyme uses a ping-pong mechanism for CoA transfer and is the first classified member of a new subclass of family I CoA transferases that has two catalytic domains on one polypeptide chain. Apparently, CarA catalyzes an energy-saving CoA loop for caffeate activation in the steady state of caffeate respiration. PMID:23315745

  9. An intermediate step in the evolution of ATPases--the F1F0-ATPase from Acetobacterium woodii contains F-type and V-type rotor subunits and is capable of ATP synthesis.

    PubMed

    Fritz, Michael; Müller, Volker

    2007-07-01

    Previous preparations of the Na(+) F(1)F(0)-ATP synthase solubilized by Triton X-100 lacked some of the membrane-embedded motor subunits [Reidlinger J & Müller V (1994) Eur J Biochem233, 275-283]. To improve the subunit recovery, we revised our purification protocol. The ATP synthase was solubilized with dodecylmaltoside and further purified to apparent homogeneity by chromatographic techniques. The preparation contained, along with the F(1) subunits, the entire membrane-embedded motor with the stator subunits a and b, and the heterooligomeric c ring, which contained the V(1)V(0)-like subunit c(1) and the F(1)F(0)-like subunits c(2) and c(3). After incorporation into liposomes, ATP synthesis could be driven by an electrochemical sodium ion potential or a potassium ion diffusion potential, but not by a sodium ion potential. This is the first demonstration that an ATPase with a V(0)-F(0) hybrid motor is capable of ATP synthesis. PMID:17555523

  10. ATP synthases with novel rotor subunits: new insights into structure, function and evolution of ATPases.

    PubMed

    Müller, Volker; Lingl, Astrid; Lewalter, Kim; Fritz, Michael

    2005-12-01

    ATPases with unusual membrane-embedded rotor subunits were found in both F(1)F(0) and A(1)A(0) ATP synthases. The rotor subunit c of A(1)A(0) ATPases is, in most cases, similar to subunit c from F(0). Surprisingly, multiplied c subunits with four, six, or even 26 transmembrane spans have been found in some archaea and these multiplication events were sometimes accompanied by loss of the ion-translocating group. Nevertheless, these enzymes are still active as ATP synthases. A duplicated c subunit with only one ion-translocating group was found along with "normal" F(0) c subunits in the Na(+) F(1)F(0) ATP synthase of the bacterium Acetobacterium woodii. These extraordinary features and exceptional structural and functional variability in the rotor of ATP synthases may have arisen as an adaptation to different cellular needs and the extreme physicochemical conditions in the early history of life. PMID:16691483

  11. Energie aus der Tiefe: Geothermische Stromerzeugung

    NASA Astrophysics Data System (ADS)

    Huenges, Ernst

    2004-11-01

    Die Erde birgt überall genug Wärme für die geothermische Erzeugung elektrischen Stroms, die allerdings Wassertemperaturen von über 150 °C braucht. So warme Gesteinsschichten liegen in Mitteleuropa in mindestens 4 km Tiefe. Ein Kraftwerk muss also beim Betrieb über tiefe Bohrungen Wasser durch das Tiefengestein zirkulieren und dort erhitzen. Von Natur aus ist das Gestein jedoch dafür meist zu wenig porös. Deshalb soll das Einpressen von Fluiden unter hohem Druck die natürlichen Risse im Reservoirgestein künstlich vergrößern. Diese Stimulationstechnik erprobte das GeoForschungsZentrum Potsdam erfolgreich an einer 4309 m tiefen Bohrung im Geothermielabor Groß Schönebeck. Eine zweite Bohrung soll nun eine langfristige Wasserzirkulation im Untergrund erforschen. Funktioniert sie stabil, dann soll eine Demonstrationsanlage Strom erzeugen.

  12. Sequence of subunit a of the Na(+)-translocating F1F0-ATPase of Acetobacterium woodii: proposal for residues involved in Na+ binding.

    PubMed

    Rahlfs, S; Müller, V

    1999-06-18

    Na+ transport through the F0 domain of Na(+)-F1F0-ATPases involves the combined action of subunits c and a but the residues involved in Na+ liganding in subunit a are unknown. As a first step towards the identification of these residues, we have cloned and sequenced the gene encoding subunit a of the Na(+)-F1F0-ATPase of Acetobacterium woodii. This is the second sequence available now for this subunit from Na(+)-F1F0-ATPases. A comparison of subunit a from Na(+)-F1F0-ATPases with those from H(+)-translocating enzymes unraveled structural similarity in a C-terminal segment including the ultimate and penultimate transmembrane helix. Seven residues are conserved in this region and, therefore, likely to be involved in Na+ liganding. PMID:10403370

  13. Diversity of corrinoids in acetogenic bacteria. P-cresolylcobamide from Sporomusa ovata, 5-methoxy-6-methylbenzimidazolylcobamide from Clostridium formicoaceticum and vitamin B12 from Acetobacterium woodii.

    PubMed

    Stupperich, E; Eisinger, H J; Kräutler, B

    1988-03-01

    The Co beta-cyanocobamides obtained by cyanide extractions from several acetogenic bacteria were structurally characterized by ultraviolet/visible spectra, proton-nuclear-magnetic-resonance spectra and fast-atom-bombardment mass spectra. p-Cresolycobamide was detected as a major corrinoid from Sporomusa ovata. This 'complete' corrinoid was isolated from an organism for the first time. Instead of the common Co alpha bases of the known and biologically active cobamides, p-cresolylcobamide contained a glycosidically bound cresolyl function that was unable to coordinate to the cobalt of the corrin ring. An additional, previously unknown corrinoid from natural sources, Co alpha-[alpha-(5-methoxy-6-methylbenzimidazolyl)]-Co beta-cyanocobamide, was isolated along with vitamin B12 from Clostridium formicoaceticum. Both homoacetogenic eubacteria were grown on methanol and contained high amounts of corrinoids (greater than 950 nmol/g cell dry mass). Less corrinoid was isolated from Acetobacterium woodii and characterized as vitamin B12. PMID:3350008

  14. Solarzellen aus Folien-Silizium: Neue Materialien der Photovoltaik

    NASA Astrophysics Data System (ADS)

    Hahn, Giso

    2004-01-01

    Die Photovoltaik wird auf absehbare Zeit vor allem kristallines Silizium als Baumaterial nutzen, mit Tendenz zu billigeren, multikristallinen Wafern. Allerdings werden heutige Wafer aus großen Silizium-Blöcken gesägt, was viel Material verpulvert. Das treibt den Anteil des Wafers an den Gesamtkosten des Solarmoduls auf 50% hoch. Folien-Silizium nutzt dagegen durch eine andere Herstellungstechnik das Material viel besser aus und senkt so die Waferkosten erheblich. Im Wirkungsgrad können Solarzellen aus Folien-Silizium schon fast mit herkömmlichen Zellen konkurrieren. Ein weiterer Vorteil von Folien-Silizium: Es kann relativ problemlos in die Produktionslinien heutiger Solarzellen aus kristallinem Silizium eingegliedert werden. Allerdings sind die attraktivsten Herstellungsverfahren noch nicht serienreif.

  15. Characterization of Two Subsurface H2-Utilizing Bacteria, Desulfomicrobium hypogeium sp. nov. and Acetobacterium psammolithicum sp. nov., and Their Ecological Roles

    PubMed Central

    Krumholz, Lee R.; Harris, Steve H.; Tay, Stephen T.; Suflita, Joseph M.

    1999-01-01

    We examined the relative roles of acetogenic and sulfate-reducing bacteria in H2 consumption in a previously characterized subsurface sandstone ecosystem. Enrichment cultures originally inoculated with ground sandstone material obtained from a Cretaceous formation in central New Mexico were grown with hydrogen in a mineral medium supplemented with 0.02% yeast extract. Sulfate reduction and acetogenesis occurred in these cultures, and the two most abundant organisms carrying out the reactions were isolated. Based on 16S rRNA analysis data and on substrate utilization patterns, these organisms were named Desulfomicrobium hypogeium sp. nov. and Acetobacterium psammolithicum sp. nov. The steady-state H2 concentrations measured in sandstone-sediment slurries (threshold concentration, 5 nM), in pure cultures of sulfate reducers (threshold concentration, 2 nM), and in pure cultures of acetogens (threshold concentrations 195 to 414 nM) suggest that sulfate reduction is the dominant terminal electron-accepting process in the ecosystem examined. In an experiment in which direct competition for H2 between D. hypogeium and A. psammolithicum was examined, sulfate reduction was the dominant process. PMID:10347005

  16. Single-carbon catabolism in acetogens: analysis of carbon flow in Acetobacterium woodii and Butyribacterium methylotrophicum by fermentation and 13C nuclear magnetic resonance measurement.

    PubMed Central

    Kerby, R; Niemczura, W; Zeikus, J G

    1983-01-01

    The catabolism of methanol, formate, or carbon monoxide to acetate or butyrate or both was examined in two acetogenic bacteria. Butyribacterium methylotrophicum simultaneously transformed methanol and formate mainly to butyrate with concomitant H2 and CO2 production and consumption. In contrast, methanol plus CO was primarily converted to acetate, and only slight amounts of CO2 were produced. In vivo 13C nuclear magnetic resonance analysis of [13C]methanol transformation by B. methylotrophicum indicated that methanol was predominantly incorporated into the methyl of acetate. 13CO2 was produced and then consumed, and butyrate was formed from the condensation of two acetate precursors. The analysis of the position of acetate labeled by a given 13C single-carbon substrate when B. methylotrophicum or Acetobacterium woodii was grown in the presence of a second one-carbon substrate indicated two trends: when methanol was consumed, CO, CO2, or formate predominantly labeled the acetate carboxyl; when CO was consumed, CO2 and formate were principally funneled into the acetate methyl group, and CO remained a better carboxyl precursor. These data suggest a model of acetate synthesis via the combined operation of two readily reversible single-carbon pathways which are linked by CO2. PMID:6411684

  17. Stoichiometry and deletion analyses of subunits in the heterotrimeric F-ATP synthase c ring from the acetogenic bacterium Acetobacterium woodii.

    PubMed

    Brandt, Karsten; Müller, Daniel B; Hoffmann, Jan; Langer, Julian D; Brutschy, Bernd; Morgner, Nina; Müller, Volker

    2016-02-01

    The ion-translocating c ring of the Na(+) F1 Fo ATP synthase of the anaerobic bacterium Acetobacterium woodii is the first heteromeric c ring found in nature that contains one V- (c1 ) and two F-type-like c subunits (c2 /c3 ), the latter of identical amino acid sequence. To address whether they are of equal or different importance for function, they were deleted in combination or individually. Deletion of c1 was compensated by incorporation of two c2 /c3 subunits but the enzyme was unstable and largely impaired in Na(+) transport. Deletion of c2 was compensated by incorporation of c3 but also led to a reduction of Na(+) transport. Deletion of c3 had no effect. In contrast, deletion of both c2 and c3 led to a complete loss of ATPase activity at the cytoplasmic membrane. Mass spectrometric analysis of c2 +1 Ala and c2 +2 Ala variants revealed a copy number of 8 : 1 for c2 /c3 which is consistent with the biochemical characteristics of the variants. These data indicate a role of c1 in assembly and a function of c2 as the predominant c ring constituent. PMID:26613566

  18. Single-carbon catabolism in acetogens: analysis of carbon flow in Acetobacterium woodii and Butyribacterium methylotrophicum by fermentation and 13C nuclear magnetic resonance measurement.

    PubMed

    Kerby, R; Niemczura, W; Zeikus, J G

    1983-09-01

    The catabolism of methanol, formate, or carbon monoxide to acetate or butyrate or both was examined in two acetogenic bacteria. Butyribacterium methylotrophicum simultaneously transformed methanol and formate mainly to butyrate with concomitant H2 and CO2 production and consumption. In contrast, methanol plus CO was primarily converted to acetate, and only slight amounts of CO2 were produced. In vivo 13C nuclear magnetic resonance analysis of [13C]methanol transformation by B. methylotrophicum indicated that methanol was predominantly incorporated into the methyl of acetate. 13CO2 was produced and then consumed, and butyrate was formed from the condensation of two acetate precursors. The analysis of the position of acetate labeled by a given 13C single-carbon substrate when B. methylotrophicum or Acetobacterium woodii was grown in the presence of a second one-carbon substrate indicated two trends: when methanol was consumed, CO, CO2, or formate predominantly labeled the acetate carboxyl; when CO was consumed, CO2 and formate were principally funneled into the acetate methyl group, and CO remained a better carboxyl precursor. These data suggest a model of acetate synthesis via the combined operation of two readily reversible single-carbon pathways which are linked by CO2. PMID:6411684

  19. Dissection of the Caffeate Respiratory Chain in the Acetogen Acetobacterium woodii: Identification of an Rnf-Type NADH Dehydrogenase as a Potential Coupling Site▿

    PubMed Central

    Imkamp, Frank; Biegel, Eva; Jayamani, Elamparithi; Buckel, Wolfgang; Müller, Volker

    2007-01-01

    The anaerobic acetogenic bacterium Acetobacterium woodii couples caffeate reduction with electrons derived from hydrogen to the synthesis of ATP by a chemiosmotic mechanism with sodium ions as coupling ions, a process referred to as caffeate respiration. We addressed the nature of the hitherto unknown enzymatic activities involved in this process and their cellular localization. Cell extract of A. woodii catalyzes H2-dependent caffeate reduction. This reaction is strictly ATP dependent but can be activated also by acetyl coenzyme A (CoA), indicating that there is formation of caffeyl-CoA prior to reduction. Two-dimensional gel electrophoresis revealed proteins present only in caffeate-grown cells. Two proteins were identified by electrospray ionization-mass spectrometry/mass spectrometry, and the encoding genes were cloned. These proteins are very similar to subunits α (EtfA) and β (EtfB) of electron transfer flavoproteins present in various anaerobic bacteria. Western blot analysis demonstrated that they are induced by caffeate and localized in the cytoplasm. Etf proteins are known electron carriers that shuttle electrons from NADH to different acceptors. Indeed, NADH was used as an electron donor for cytosolic caffeate reduction. Since the hydrogenase was soluble and used ferredoxin as an electron acceptor, the missing link was a ferredoxin:NAD+ oxidoreductase. This activity could be determined and, interestingly, was membrane bound. A search for genes that could encode this activity revealed DNA fragments encoding subunits C and D of a membrane-bound Rnf-type NADH dehydrogenase that is a potential Na+ pump. These data suggest the following electron transport chain: H2 → ferredoxin → NAD+ → Etf → caffeyl-CoA reductase. They also imply that the sodium motive step in the chain is the ferredoxin-dependent NAD+ reduction catalyzed by Rnf. PMID:17873051

  20. Functional production of the Na+ F1F(O) ATP synthase from Acetobacterium woodii in Escherichia coli requires the native AtpI.

    PubMed

    Brandt, Karsten; Müller, Daniel B; Hoffmann, Jan; Hübert, Christine; Brutschy, Bernd; Deckers-Hebestreit, Gabriele; Müller, Volker

    2013-02-01

    The Na(+) F(1)F(O) ATP synthase of the anaerobic, acetogenic bacterium Acetobacterium woodii has a unique F(O)V(O) hybrid rotor that contains nine copies of a F(O)-like c subunit and one copy of a V(O)-like c(1) subunit with one ion binding site in four transmembrane helices whose cellular function is obscure. Since a genetic system to address the role of different c subunits is not available for this bacterium, we aimed at a heterologous expression system. Therefore, we cloned and expressed its Na(+) F(1)F(O) ATP synthase operon in Escherichia coli. A Δatp mutant of E. coli produced a functional, membrane-bound Na(+) F(1)F(O) ATP synthase that was purified in a single step after inserting a His(6)-tag to its β subunit. The purified enzyme was competent in Na(+) transport and contained the F(O)V(O) hybrid rotor in the same stoichiometry as in A. woodii. Deletion of the atpI gene from the A. woodii operon resulted in a loss of the c ring and a mis-assembled Na(+) F(1)F(O) ATP synthase. AtpI from E. coli could not substitute AtpI from A. woodii. These data demonstrate for the first time a functional production of a F(O)V(O) hybrid rotor in E. coli and revealed that the native AtpI is required for assembly of the hybrid rotor. PMID:23054076

  1. Dissection of the caffeate respiratory chain in the acetogen Acetobacterium woodii: identification of an Rnf-type NADH dehydrogenase as a potential coupling site.

    PubMed

    Imkamp, Frank; Biegel, Eva; Jayamani, Elamparithi; Buckel, Wolfgang; Müller, Volker

    2007-11-01

    The anaerobic acetogenic bacterium Acetobacterium woodii couples caffeate reduction with electrons derived from hydrogen to the synthesis of ATP by a chemiosmotic mechanism with sodium ions as coupling ions, a process referred to as caffeate respiration. We addressed the nature of the hitherto unknown enzymatic activities involved in this process and their cellular localization. Cell extract of A. woodii catalyzes H(2)-dependent caffeate reduction. This reaction is strictly ATP dependent but can be activated also by acetyl coenzyme A (CoA), indicating that there is formation of caffeyl-CoA prior to reduction. Two-dimensional gel electrophoresis revealed proteins present only in caffeate-grown cells. Two proteins were identified by electrospray ionization-mass spectrometry/mass spectrometry, and the encoding genes were cloned. These proteins are very similar to subunits alpha (EtfA) and beta (EtfB) of electron transfer flavoproteins present in various anaerobic bacteria. Western blot analysis demonstrated that they are induced by caffeate and localized in the cytoplasm. Etf proteins are known electron carriers that shuttle electrons from NADH to different acceptors. Indeed, NADH was used as an electron donor for cytosolic caffeate reduction. Since the hydrogenase was soluble and used ferredoxin as an electron acceptor, the missing link was a ferredoxin:NAD(+) oxidoreductase. This activity could be determined and, interestingly, was membrane bound. A search for genes that could encode this activity revealed DNA fragments encoding subunits C and D of a membrane-bound Rnf-type NADH dehydrogenase that is a potential Na(+) pump. These data suggest the following electron transport chain: H(2) --> ferredoxin --> NAD(+) --> Etf --> caffeyl-CoA reductase. They also imply that the sodium motive step in the chain is the ferredoxin-dependent NAD(+) reduction catalyzed by Rnf. PMID:17873051

  2. The Ferredoxin:NAD+ Oxidoreductase (Rnf) from the Acetogen Acetobacterium woodii Requires Na+ and Is Reversibly Coupled to the Membrane Potential*

    PubMed Central

    Hess, Verena; Schuchmann, Kai; Müller, Volker

    2013-01-01

    The anaerobic acetogenic bacterium Acetobacterium woodii has a novel Na+-translocating electron transport chain that couples electron transfer from reduced ferredoxin to NAD+ with the generation of a primary electrochemical Na+ potential across its cytoplasmic membrane. In previous assays in which Ti3+ was used to reduce ferredoxin, Na+ transport was observed, but not a Na+ dependence of the electron transfer reaction. Here, we describe a new biological reduction system for ferredoxin in which ferredoxin is reduced with CO, catalyzed by the purified acetyl-CoA synthase/CO dehydrogenase from A. woodii. Using CO-reduced ferredoxin, NAD+ reduction was highly specific and strictly dependent on ferredoxin and occurred at a rate of 50 milliunits/mg of protein. Most important, this assay revealed for the first time a strict Na+ dependence of this electron transfer reaction. The Km was 0.2 mm. Na+ could be partly substituted by Li+. Na+ dependence was observed at neutral and acidic pH values, indicating the exclusive use of Na+ as a coupling ion. Electron transport from reduced ferredoxin to NAD+ was coupled to electrogenic Na+ transport, indicating the generation of Δμ̃Na+. Vice versa, endergonic ferredoxin reduction with NADH as reductant was possible, but only in the presence of Δμ̃Na+, and was accompanied by Na+ efflux out of the vesicles. This is consistent with the hypothesis that Rnf also catalyzes ferredoxin reduction at the expense of an electrochemical Na+ gradient. The physiological significance of this finding is discussed. PMID:24045950

  3. The ferredoxin:NAD+ oxidoreductase (Rnf) from the acetogen Acetobacterium woodii requires Na+ and is reversibly coupled to the membrane potential.

    PubMed

    Hess, Verena; Schuchmann, Kai; Müller, Volker

    2013-11-01

    The anaerobic acetogenic bacterium Acetobacterium woodii has a novel Na(+)-translocating electron transport chain that couples electron transfer from reduced ferredoxin to NAD(+) with the generation of a primary electrochemical Na(+) potential across its cytoplasmic membrane. In previous assays in which Ti(3+) was used to reduce ferredoxin, Na(+) transport was observed, but not a Na(+) dependence of the electron transfer reaction. Here, we describe a new biological reduction system for ferredoxin in which ferredoxin is reduced with CO, catalyzed by the purified acetyl-CoA synthase/CO dehydrogenase from A. woodii. Using CO-reduced ferredoxin, NAD(+) reduction was highly specific and strictly dependent on ferredoxin and occurred at a rate of 50 milliunits/mg of protein. Most important, this assay revealed for the first time a strict Na(+) dependence of this electron transfer reaction. The Km was 0.2 mm. Na(+) could be partly substituted by Li(+). Na(+) dependence was observed at neutral and acidic pH values, indicating the exclusive use of Na(+) as a coupling ion. Electron transport from reduced ferredoxin to NAD(+) was coupled to electrogenic Na(+) transport, indicating the generation of ΔμNa(+). Vice versa, endergonic ferredoxin reduction with NADH as reductant was possible, but only in the presence of ΔμNa(+), and was accompanied by Na(+) efflux out of the vesicles. This is consistent with the hypothesis that Rnf also catalyzes ferredoxin reduction at the expense of an electrochemical Na(+) gradient. The physiological significance of this finding is discussed. PMID:24045950

  4. Metabolism of the /sup 18/O-methoxy substituent of 3-methoxybenzoic acid and other unlabeled methoxybenzoic acids by anaerobic bacteria. [Eubacterium limosum; Acetobacterium woodil; Syntrophococcus; Clostridium; Desulfotomaculum; Enterobacter

    SciTech Connect

    DeWeerd, J.A.; Saxena, A.; Nagle, D.P. Jr.; Sulflita, J.M.

    1988-05-01

    The mechanism of the bioconversion of methoxylated benzoic acids to the hydroxylated derivatives was investigated with a model substrate and cultures of one anaerobic consortium, eight strict anaerobic bacteria, and one facultative anaerobic microorganism. We found that a haloaromatic dehalogenating consortium, a dehalogenating isolate from that consortium, Eubacterium, limosum, and a strain of Acetobacterium woodii metabolized 3-(methoxy-/sup 18/O)methoxybenzoic acid (3-anisic acid) to 3-(hydroxy-/sup 18/O)hydroxybenzoic acid stoichiometrically at rates of 1.5, 3.2, 52.4, and 36.7 nmol/min per mg of protein, respectively. A different strain of Acetobacterium and strains of Syntrophococcus, Clostridium Desulfotomaculum, Enterobacter, and an anaerobic bacterium, strain TH-001, were unable to transform this compound. The O-demethylating ability of E. limosum was induced only with appropriate methoxylated benzoates but not with D-glucose, lactate, isoleucine, or methanol. Cross-acclimation and growth experiments with E. limosum showed a rate of metabolism that was an order of magnitude slower and showed no growth with either 4-methoxysalicylic acid (2-hydroxy-4-methoxybenzoic acid) or 4-anisic acid (4-methoxybenzoic acid) when adapted to 3-anisic acid. However, A. woodii NZva-16 showed slower rates and no growth with 3- or 4-methoxysalicylic acid when adapted to 3-anisic acid in similar experiments.

  5. Vollautomatische Segmentierung der Prostata aus 3D-Ultraschallbildern

    NASA Astrophysics Data System (ADS)

    Heimann, Tobias; Simpfendörfer, Tobias; Baumhauer, Matthias; Meinzer, Hans-Peter

    Diese Arbeit beschreibt ein modellbasiertes Verfahren zur Segmentierung der Prostata aus 3D-Ultraschalldaten. Kern der Methode ist ein statistisches Formmodell, das auf Beispieldaten der Prostata trainiert wird. Erster Schritt der Segmentierung ist ein evolutionärer Algorithmus, mit dem das Modell grob im zu segmentierenden Bild positioniert wird. Für die darauf folgende lokale Suche wurden mehrere Varianten des Algorithmus evaluiert, unter anderem Ausreißer-Unterdrückung, freie Deformation und Gewichtung der verwendeten Erscheinungsmodelle nach ihrer Zuverlässigkeit. Alle Varianten wurden auf 35 Ultraschallbildern getestet und mit manuellen Referenzsegmentierungen verglichen. Die beste Variante erreichte eine durchschnittliche Oberflächenabweichung von 1.1 mm.

  6. The Na(+)-translocating ATPase of Acetobacterium woodii is a F1F0-type enzyme as deduced from the primary structure of its beta, gamma and epsilon subunits.

    PubMed

    Forster, A; Daniel, R; Müller, V

    1995-05-10

    A 4.5 kbp EcoRI fragment hybridizing to a fragment of uncD (coding for subunit beta of F1F0-ATPases) was cloned from chromosomal DNA of Acetobacterium woodii. The nucleotide sequence was determined and revealed five open reading frames (ORF), four of which were identified to code for subunits of the Na(+)-ATPase. The deduced amino acid sequences of these ORF's are homologous to subunit alpha (partial coding sequence, C-terminal end), gamma, beta and epsilon of F1F0-ATPases from various organisms; furthermore, the organization of the genes in the order uncA (alpha), uncG (gamma), uncD (beta), uncC (epsilon) is identical to the structure of unc operon as present in most bacteria. Downstream of uncC is an ORF whose deduced amino acid sequence has 53% sequence homology to AlgD from Pseudomonas aeruginosa. The structure and organization of the unc genes are the final proof that the Na(+)-ATPase from A. woodii is a member of the family of F1F0-ATPases. PMID:7748890

  7. The Na(+) cycle in Acetobacterium woodii: identification and characterization of a Na(+) translocating F(1)F(0)-ATPase with a mixed oligomer of 8 and 16 kDa proteolipids.

    PubMed

    Müller, V; Aufurth, S; Rahlfs, S

    2001-05-01

    The homoacetogenic bacterium Acetobacterium woodii relies on a sodium ion current across its cytoplasmic membrane for energy-dependent reactions. The sodium ion potential is established by a yet to be identified primary, electrogenic pump connected to the Wood-Ljungdahl pathway. Reactions possibly involved in Na(+) export are discussed. The electrochemical sodium ion potential generated is used to drive endergonic reactions such as flagellar rotation and ATP synthesis. Biochemical and molecular data identified the Na(+)-ATPase of A. woodii as a typical member of the F(1)F(0) class of ATPases. Its catalytic properties and the hypothetical sodium ion binding site in subunit c are discussed. The encoding genes were cloned and, surprisingly, the atp operon was shown to contain multiple copies of genes encoding subunit c. Two copies encode identical 8 kDa proteolipids, and a third copy arose by duplication and subsequent fusion of two genes. Furthermore, the duplicated subunit c does not contain the ion binding site in hair pin two. Biochemical and molecular data revealed that all three copies of subunit c constitute a mixed oligomer. The evolution of the structure and function of subunit c in ATPases from eucarya, bacteria, and archaea is discussed. PMID:11248193

  8. Identification of subunits a, b, and c1 from Acetobacterium woodii Na+-F1F0-ATPase. Subunits c1, c2, AND c3 constitute a mixed c-oligomer.

    PubMed

    Aufurth, S; Schägger, H; Müller, V

    2000-10-27

    The Na(+)-F(1)F(0)-ATPase operon of Acetobacterium woodii was recently shown to contain, among eleven atp genes, those genes that encode subunit a and b, a gene encoding a 16-kDa proteolipid (subunit c(1)), and two genes encoding 8-kDa proteolipids (subunits c(2) and c(3)). Because subunits a, b, and c(1) were not found in previous enzyme preparations, we re-determined the subunit composition of the enzyme. The genes were overproduced, and specific antibodies were raised. Western blots revealed that subunits a, b, and c(1) are produced and localized in the cytoplasmic membrane. Membrane protein complexes were solubilized by dodecylmaltoside and separated by blue native-polyacrylamide gel electrophoresis, and the ATPase subunits were resolved by SDS-polyacrylamide gel electrophoresis. N-terminal sequence analyses revealed the presence of subunits a, c(2), c(3), b, delta, alpha, gamma, beta, and epsilon. Biochemical and immunological analyses revealed that subunits c(1), c(2), and c(3) are all part of the c-oligomer, the first of a F(1)F(0)-ATPase that contains 8- and 16-kDa proteolipids. PMID:10913149

  9. The Na(+)-F(1)F(0)-ATPase operon from Acetobacterium woodii. Operon structure and presence of multiple copies of atpE which encode proteolipids of 8- and 18-kda.

    PubMed

    Rahlfs, S; Aufurth, S; Müller, V

    1999-11-26

    Eight genes (atpI, atpB, atpE(1), atpE(2), atpE(3), atpF, atpH, and atpA) upstream of and contiguous with the previously described genes atpG, atpD, and atpC were cloned from chromosomal DNA of Acetobacterium woodii. Northern blot analysis revealed that the eleven atp genes are transcribed as a polycistronic message. The atp operon encodes the Na(+)-F(1)F(0)-ATPase of A. woodii, as evident from a comparison of the biochemically derived N termini of the subunits with the amino acid sequences deduced from the DNA sequences. The molecular analysis revealed that all of the F(1)F(0)-encoding genes from Escherichia coli have homologs in the Na(+)-F(1)F(0)-ATPase operon from A. woodii, despite the fact that only six subunits were found in previous preparations of the enzyme from A. woodii. These results unequivocally prove that the Na(+)-ATPase from A. woodii is an enzyme of the F(1)F(0) class. Most interestingly, the gene encoding the proteolipid underwent quadruplication. Two gene copies (atpE(2) and atpE(3)) encode identical 8-kDa proteolipids. Two additional gene copies were fused to form the atpE(1) gene. Heterologous expression experiments as well as immunolabeling studies with native membranes revealed that atpE(1) encodes a duplicated 18-kDa proteolipid. This is the first demonstration of multiplication and fusion of proteolipid-encoding genes in F(1)F(0)-ATPase operons. Furthermore, AtpE(1) is the first duplicated proteolipid ever found to be encoded by an F(1)F(0)-ATPase operon. PMID:10567365

  10. Das Lektin aus der Erbse Pisum sativum : Bindungsstudien, Monomer-Dimer-Gleichgewicht und Rückfaltung aus Fragmenten

    NASA Astrophysics Data System (ADS)

    Küster, Frank

    2002-11-01

    Das Lektin aus Pisum sativum, der Gartenerbse, ist Teil der Familie der Leguminosenlektine. Diese Proteine haben untereinander eine hohe Sequenzhomologie, und die Struktur ihrer Monomere, ein all-ß-Motiv, ist hoch konserviert. Dagegen gibt es innerhalb der Familie eine große Vielfalt an unterschiedlichen Quartärstrukturen, die Gegenstand kristallographischer und theoretischer Arbeiten waren. Das Erbsenlektin ist ein dimeres Leguminosenlektin mit einer Besonderheit in seiner Struktur: Nach der Faltung in der Zelle wird aus einem Loop eine kurze Aminosäuresequenz herausgeschnitten, so dass sich in jeder Untereinheit zwei unabhängige Polypeptidketten befinden. Beide Ketten sind aber stark miteinander verschränkt und bilden eine gemeinsame strukturelle Domäne. Wie alle Lektine bindet Erbsenlektin komplexe Oligosaccharide, doch sind seine physiologische Rolle und der natürliche Ligand unbekannt. In dieser Arbeit wurden Versuche zur Entwicklung eines Funktionstests für Erbsenlektin durchgeführt und seine Faltung, Stabilität und Monomer-Dimer-Gleichgewicht charakterisiert. Um die spezifische Rolle der Prozessierung für Stabilität und Faltung zu untersuchen, wurde ein unprozessiertes Konstrukt in E. coli exprimiert und mit der prozessierten Form verglichen. Beide Proteine zeigen die gleiche kinetische Stabilität gegenüber chemischer Denaturierung. Sie denaturieren extrem langsam, weil nur die isolierten Untereinheiten entfalten können und das Monomer-Dimer-Gleichgewicht bei mittleren Konzentrationen an Denaturierungsmittel auf der Seite der Dimere liegt. Durch die extrem langsame Entfaltung zeigen beide Proteine eine apparente Hysterese im Gleichgewichtsübergang, und es ist nicht möglich, die thermodynamische Stabilität zu bestimmen. Die Stabilität und die Geschwindigkeit der Assoziation und Dissoziation in die prozessierten bzw. nichtprozessierten Untereinheiten sind für beide Proteine gleich. Darüber hinaus konnte gezeigt werden, dass auch unter

  11. Triage of patients with AUS/FLUS on thyroid cytopathology: effectiveness of the multimodal diagnostic techniques.

    PubMed

    Kim, Tae Hyuk; Jeong, Dae Joon; Hahn, Soo Yeon; Shin, Jung Hee; Oh, Young Lyun; Ki, Chang-Seok; Kim, Jong-Won; Jang, Ju Young; Cho, Yoon Young; Chung, Jae Hoon; Kim, Sun Wook

    2016-05-01

    The management of patients with thyroid cytopathologic diagnosis of atypia (or follicular lesion) of undetermined significance (AUS/FLUS) is a complex clinical problem. The purpose of this study was to develop a practical triage scheme based on multiple diagnostic tests in general use. We performed a retrospective cohort study involving 15,335 consecutive patients with a referral diagnosis of thyroid nodule between April 2011 and March 2015 using an institutional database. We obtained 904 patients with an initial cytopathologic diagnosis of AUS/FLUS who underwent repeat fine-needle aspiration or core needle biopsy, 388 of whom had a corresponding histopathological diagnosis for excised index lesions. The diagnostic performance of ultrasound (US) findings, repeat biopsy, and BRAF(V) (600E) mutation in cytopathologic specimens were evaluated individually or as a set. Of the 388 resected AUS/FLUS cases, 338 (87.1%) were thyroid cancer. The positive likelihood ratios (LRs) for BRAF(V) (600E) mutation and repeat biopsy result of suspicious for malignant cell (SMC) or worse were 11.6 (95% CI = 1.7-77.8) and 13.7 (95% CI = 4.6-41.0), respectively. The absence of suspicious findings on US combined with cytologic result of less than SMC or negative BRAF(V) (600E) mutation produced negative LRs ranging from 0.06 to 0.15, corresponding to negative predictive values of over 90% in both primary and referral settings. For patients with AUS/FLUS cytopathology, clinical decision making can be guided by a simple triage scheme based on US findings, repeat biopsy, or BRAF(V) (600E) mutation. PMID:26775803

  12. Establishing the Aus-ROC Australian and New Zealand out-of-hospital cardiac arrest Epistry

    PubMed Central

    Bray, Janet; Smith, Karen; Walker, Tony; Grantham, Hugh; Hein, Cindy; Thorrowgood, Melanie; Smith, Anthony; Smith, Tony; Dicker, Bridget; Swain, Andy; Bailey, Mark; Bosley, Emma; Pemberton, Katherine; Cameron, Peter; Nichol, Graham; Finn, Judith

    2016-01-01

    Introduction Out-of-hospital cardiac arrest (OHCA) is a global health problem with low survival. Regional variation in survival has heightened interest in combining cardiac arrest registries to understand and improve OHCA outcomes. While individual OHCA registries exist in Australian and New Zealand ambulance services, until recently these registries have not been combined. The aim of this protocol paper is to describe the rationale and methods of the Australian Resuscitation Outcomes Consortium (Aus-ROC) OHCA epidemiological registry (Epistry). Methods and analysis The Aus-ROC Epistry is designed as a population-based cohort study. Data collection started in 2014. Six ambulance services in Australia (Ambulance Victoria, SA Ambulance Service, St John Ambulance Western Australia and Queensland Ambulance Service) and New Zealand (St John New Zealand and Wellington Free Ambulance) currently contribute data. All OHCA attended by ambulance, regardless of aetiology or patient age, are included in the Epistry. The catchment population is approximately 19.3 million persons, representing 63% of the Australian population and 100% of the New Zealand population. Data are collected using Utstein-style definitions. Information incorporated into the Epistry includes demographics, arrest features, ambulance response times, treatment and patient outcomes. The primary outcome is ‘survival to hospital discharge’, with ‘return of spontaneous circulation’ as a key secondary outcome. Ethics and dissemination Ethics approval was independently sought by each of the contributing registries. Overarching ethics for the Epistry was provided by Monash University HREC (Approval No. CF12/3938—2012001888). A population-based OHCA registry capturing the majority of Australia and New Zealand will allow risk-adjusted outcomes to be determined, to enable benchmarking across ambulance providers, facilitate the identification of system-wide strategies associated with survival from OHCA, and

  13. Using NOAA/AVHRR based remote sensing data and PCR method for estimation of Aus rice yield in Bangladesh

    NASA Astrophysics Data System (ADS)

    Nizamuddin, Mohammad; Akhand, Kawsar; Roytman, Leonid; Kogan, Felix; Goldberg, Mitch

    2015-06-01

    Rice is a dominant food crop of Bangladesh accounting about 75 percent of agricultural land use for rice cultivation and currently Bangladesh is the world's fourth largest rice producing country. Rice provides about two-third of total calorie supply and about one-half of the agricultural GDP and one-sixth of the national income in Bangladesh. Aus is one of the main rice varieties in Bangladesh. Crop production, especially rice, the main food staple, is the most susceptible to climate change and variability. Any change in climate will, thus, increase uncertainty regarding rice production as climate is major cause year-to-year variability in rice productivity. This paper shows the application of remote sensing data for estimating Aus rice yield in Bangladesh using official statistics of rice yield with real time acquired satellite data from Advanced Very High Resolution Radiometer (AVHRR) sensor and Principal Component Regression (PCR) method was used to construct a model. The simulated result was compared with official agricultural statistics showing that the error of estimation of Aus rice yield was less than 10%. Remote sensing, therefore, is a valuable tool for estimating crop yields well in advance of harvest, and at a low cost.

  14. A nanosensor for in vivo selenol imaging based on the formation of AuSe bonds.

    PubMed

    Hu, Bo; Cheng, Ranran; Liu, Xiaojun; Pan, Xiaohong; Kong, Fanpeng; Gao, Wen; Xu, Kehua; Tang, Bo

    2016-06-01

    Selenol is a key metabolite of Na2SeO3 and plays an important role in many physiological and pathological processes. The real-time monitoring of selenol is of scientific interest for understanding the anti-cancer mechanism of Na2SeO3. Based on selenol's ability to specifically break AuS bonds and form more stable AuSe bonds on the surfaces of gold nanoparticles (AuNPs), we developed a novel near-infrared fluorescent nanosensor (Cy5.5-peptide-AuNPs) for detecting selenol. The nanosensor exhibited rapid response to selenol with high selectivity and sensitivity, and it was successfully used to image changes in the selenol level in HepG2 cells during Na2SeO3-induced apoptosis. Moreover, in vivo fluorescence imaging of selenol was obtained from H22 tumor-bearing mice injected with both the nanosensor and sodium selenite. The results showed that the tumor cell apoptosis induced by Na2SeO3 is correlated with high-level of selenol under hypoxic conditions. We believe that this nanosensor could serve as a powerful tool for monitoring selenol and exploring the physiological function of selenol in a variety of physiological and pathological contexts and that the probe-designed strategy will provide a new platform for research on relevant selenium chemistry. PMID:27043769

  15. Die Anfaenge der Melker Bibliothek - Neue Erkenntnisse zu Handschriften und Fragmenten aus der Zeit vor 1200

    NASA Astrophysics Data System (ADS)

    Glaßner, Christine; Haidinger, Alois

    1996-04-01

    Untersuchung der zeitnahen Eintragungen in diese Handschrift gelang es, die Tätigkeit von zumindest drei wichtigen, im 12. Jahrhundert in Melk identifizierbaren, namentlich nicht bekannten Schreibern chronologisch zuzuordnen. Erstmals wurden die nur fragmentarisch als Makulatur in den Bucheinbänden erhaltenen Handschriften in die Untersuchung einbezogen, so dass für die Wende vom 12. zum 13. Jahrhundert ein Bücherbestand von 68 Handschriften erschlossen werden konnte. Besonders hervorzuheben ist, dass in der Sonderausstellung von 1996 und im Begleitband erstmals eingehend die Bedeutung der ältesten Melker Handschrift, Cod. 412 aus dem frühen 9. Jahrhundert mit naturwissenschaftlichen Texten des Beda Venerabilis, als Vorlage für drei weitere Handschriften diente: Vatikan, Cod. Vat. lat. 643, abgeschrieben wahrscheinlich in Melk, davon abhängig Zwettl, Cod. 296, und Klosterneuburg, Cod. 685. Die Abschriften der Melker Beda-Handschrift sind inhaltlich fast identisch, allerdings um den im Mittelalter fälschlicherweise Beda Venerabilis zugeschriebenen Sternbilderkatalog erweitert.

  16. Diagnostic Thyroidectomy May Be Preferable in Patients With Suspicious Ultrasonography Features After Cytopathology Diagnosis of AUS/FLUS in the Bethesda System.

    PubMed

    Lee, Yong Sang; Kim, Hyeung Kyoo; Chang, Hojin; Kim, Seok Mo; Kim, Bup-Woo; Chang, Hang-Seok; Park, Cheong Soo

    2015-12-01

    Atypia/follicular lesion of undetermined significance (AUS/FLUS) is a new category in the Bethesda System for Reporting Thyroid Cytopathology (BSRTC) for which repeat fine-needle aspiration cytology (FNAC) is recommended. The aim of this study was to identify specific ultrasonography and clinical predictors of malignancy in a subset of thyroid nodules associated with cytology diagnoses of AUS/FLUS.Between January 2011 and December 2102, 5440 patients underwent thyroid surgery at our institution. Of these, 213 patients were diagnosed AUS/FLUS at the preoperative cytopathology diagnosis. The frequency of FNAC and ultrasonography images was compared between patients with cancerous and benign tumors based on their final pathology.Of the 213 patients, 158 (74.2%) were diagnosed with thyroid carcinoma in their final pathology reports. In univariate and multivariate analyses, the frequency of FNAC was not significantly correlated with the cancer diagnosis. Hypoechogenicity (odds ratio 2.521, P = 0.007) and microcalcification (odds ratio 3.247, P = 0.005) were statistically correlated with cancer risk.Although AUS/FLUS in cytopathology is recommended for repeating FNAC in BSRTC, we proposed that thyroid nodules with ultrasonography findings that suggest the possibility of cancer should undergo thyroidectomy with diagnostic intent. PMID:26705204

  17. The Quintessential Bond of Modern Science. The Detection and Characterization of Diatomic Gold Sulfide, AuS.

    NASA Astrophysics Data System (ADS)

    Kokkin, Damian L.; Zhang, Ruohan; Steimle, Timothy; Pearlman, Bradley W.; Wyse, Ian A.; Varberg, Thomas D.

    2015-06-01

    The gold sulfur bond is becoming ever more important to a vast range of scientific endeavors. We have recorded the electronic spectrum of gas-phase AuS, at vibrational resolution, over the 440-740 nm wavelength range. By application of a synergy of production techniques, hot hollow-cathode sputtering source and cold laser ablation molecular beam source, excitation from both spin components of the inverted ^2Π ground state is possible. Excitation into four different excited electronic states involving approximately 100 red-degraded bands has been observed. The four excited states have been characterized as a^4σ1/2, A^2σ^+1/2, B^2σ^-1/2 and C^2Δ_i. The observed red-degraded vibronic bands where then globally analyzed to determine an accurate set of term energies and vibrational constants for the excited and ground electronic states. The electronic configurations from which these states arise will be discussed.

  18. AusEinetter, 1998.

    ERIC Educational Resources Information Center

    AusEinetter, 1998

    1998-01-01

    This publication contains the 1998 issues of the Australian Early Intervention Network for Mental Health in Young People newsletters for health professionals. The newsletters disseminate information about the national and local initiatives for intervention and prevention of mental health problems in young children and youth. Each issue also offers…

  19. AusEinetter, 1999.

    ERIC Educational Resources Information Center

    AusEinetter, 1999

    1999-01-01

    This document contains issues eight and nine of the 1999 Australian Early Intervention Network for Mental Health in Young People newsletters for health professionals. The newsletters disseminate information about the national and local initiatives for intervention and prevention of mental health problems in young children and youth. The issues…

  20. The AusD Study: a population-based study of the determinants of serum 25-hydroxyvitamin D concentration across a broad latitude range.

    PubMed

    Brodie, A M; Lucas, R M; Harrison, S L; van der Mei, I A F; Armstrong, B; Kricker, A; Mason, R S; McMichael, A J; Nowak, M; Whiteman, D C; Kimlin, M G

    2013-05-01

    Observational studies suggest that people with a high serum 25-hydroxyvitamin D (25(OH)D) concentration may have reduced risk of chronic diseases such as osteoporosis, multiple sclerosis, type 1 diabetes, cardiovascular disease, and some cancers. The AusD Study (A Quantitative Assessment of Solar UV Exposure for Vitamin D Synthesis in Australian Adults) was conducted to clarify the relationships between ultraviolet (UV) radiation exposure, dietary intake of vitamin D, and serum 25(OH)D concentration among Australian adults residing in Townsville (19.3°S), Brisbane (27.5°S), Canberra (35.3°S), and Hobart (42.8°S). Participants aged 18-75 years were recruited from the Australian Electoral Roll between 2009 and 2010. Measurements were made of height, weight, waist:hip ratio, skin, hair, and eye color, blood pressure, and grip strength. Participants completed a questionnaire on sun exposure and vitamin D intake, together with 10 days of personal UV dosimetry and an associated sun-exposure and physical-activity diary that was temporally linked to a blood test for measurement of 25(OH)D concentration. Ambient solar UV radiation was also monitored at all study sites. We collected comprehensive, high-quality data from 1,002 participants (459 males, 543 females) assessed simultaneously across a range of latitudes and through all seasons. Here we describe the scientific and methodological issues considered in designing the AusD Study. PMID:23524036

  1. Identification of Novel Mitochondrial Protein Components of Chlamydomonas reinhardtii. A Proteomic Approach1

    PubMed Central

    van Lis, Robert; Atteia, Ariane; Mendoza-Hernández, Guillermo; González-Halphen, Diego

    2003-01-01

    Pure mitochondria of the photosynthetic alga Chlamydomonas reinhardtii were analyzed using blue native-polyacrylamide gel electrophoresis (BN-PAGE). The major oxidative phosphorylation complexes were resolved: F1F0-ATP synthase, NADH-ubiquinone oxidoreductase, ubiquinol-cytochrome c reductase, and cytochrome c oxidase. The oligomeric states of these complexes were determined. The F1F0-ATP synthase runs exclusively as a dimer, in contrast to the C. reinhardtii chloroplast enzyme, which is present as a monomer and subcomplexes. The sequence of a 60-kD protein, associated with the mitochondrial ATP synthase and with no known counterpart in any other organism, is reported. This protein may be related to the strong dimeric character of the algal F1F0-ATP synthase. The oxidative phosphorylation complexes resolved by BN-PAGE were separated into their subunits by second dimension sodium dodecyl sulfate-PAGE. A number of polypeptides were identified mainly on the basis of their N-terminal sequence. Core I and II subunits of complex III were characterized, and their proteolytic activities were predicted. Also, the heterodimeric nature of COXIIA and COXIIB subunits in cytochrome c oxidase was demonstrated. Other mitochondrial proteins like the chaperone HSP60, the alternative oxidase, the aconitase, and the ADP/ATP carrier were identified. BN-PAGE was also used to approach the analysis of the major chloroplast protein complexes of C. reinhardtii. PMID:12746537

  2. Lineare und verzweigte Blockcopolymere aus Polypeptiden und synthetischen Polymeren

    NASA Astrophysics Data System (ADS)

    Kukula, Hildegard

    2001-07-01

    Die vorliegende Arbeit beschäftigt sich mit der Synthese und den Eigenschaften von linearen und verzweigten amphiphilen Polypeptid-Blockcopolymeren. Die Frage nach dem Einfluss der Topologie und Konformation der Blockcopolymere auf die supramolekularen und kolloidalen Eigenschaften bildete einen wichtigen Aspekt bei den Untersuchungen. Die Blockcopolymere wurden nach einem mehrstufigen Reaktionsschema durch Kombination von anionischer und ringöffnender Polymerisation von Aminosäuren-N-Carboxyanhydriden (NCA) synthetisiert. Die Untersuchung der Polypeptid-Blockcopolymere hinsichtlich ihres Aggregationsverhaltens in fester Phase sowie in verdünnter wässriger Lösung erfolgte mittels Streumethoden (SAXS, WAXS, DLS) sowie abbildender Methoden (TEM). Durch Einsatz der Blockcopolymere als polymere Stabilisatoren in der Emulsionspolymerisation wurden Oberflächen funktionalisierte Latizes erhalten. Als Beispiel für eine pharmazeutische Anwendung wurden bioverträgliche Polypeptid-Blockcopolymere als Wirkstoff-Trägersysteme in der Krebstherapie eingesetzt. This work describes the synthesis and characterization of linear and branched polypeptide block copolymers having amphiphilic character. The studies focused on the impact of the block copolymers' conformation and architecture on the supramolecular and colloidal properties. The polypeptide block copolymers were prepared in a multi-step process involving the anionic synthesis of (poly)amino-functional polymers (polystyrene and polybutadiene) which where used as macroinitiators for the ring-opening polymerization of N-carboxyanhydrides (NCA) of protected a-aminoacids. Supramolecular structures of the block copolymers in the solid state as well as in diluted aqueous solution were investigated using scattering (SAXS, WAXS, DLS) and microscopic (TEM) methods. Both linear and branched polypeptide block copolymers were used as polymeric stabilizers in the emulsion polymerization of styrene to yield polypeptide-decorated latexes. Biocompatible block copolymers were used as drug-delivery systems in lymphatic cancer therapy.

  3. Mikro- und Nanokapseln aus Funktionspolymeren, Biopolymeren und Proteinen

    NASA Astrophysics Data System (ADS)

    Schüler, Corinna

    2001-03-01

    In dieser Arbeit wird die Beschichtung von kolloidalen Templaten mit Hilfe der Layer-by-layer Technik beschrieben. Mit ihr ist es möglich, die Oberfläche der Template mit sehr dünnen und gut definierten Filmen zu versehen. Durch Auflösung der Template werden Kapseln hergestellt, die je nach Zusammensetzung der Beschichtung unterschiedliche Eigenschaften aufweisen. In this thesis the coating of colloid templates using the layer-by-layer technique is described. The surface of the templates is modified with thin, well defined films. After dissolving the templates, hollow capsules with different properties are obtained.

  4. Political Participation of Non-Citzens in Germany and Western Europe. (Beitrage aus dem Fachbereich Padagogik).

    ERIC Educational Resources Information Center

    Reuter, Lutz R.

    This paper compares the present social, economic, and political rights labor immigrants enjoy within the European Community (EC). Its focus is the current debate about the municipal suffrage of permanent residents. The dual relevance of the topic is obvious. EC bodies like the Commission, Council of Ministers, Political Council, and European…

  5. Materials Data on Ag3AuS2 (SG:1) by Materials Project

    SciTech Connect

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  6. Persönlichkeitsentwicklung als ziel der Bildung: Aus der Sicht eines Psychologen

    NASA Astrophysics Data System (ADS)

    Heinze, Burger

    1990-06-01

    Personality, which is a term almost always used in a positive sense, does not exist from the moment of birth, but it develops under the influence of heredity and environment. Adolescence, which is seen as a transition from childhood to adulthood, raises difficulties in many modern industrialized countries as a result of the often arduous search for individual identity. In this context identity is seen as an interaction between heredity and environment. While developing his own personality, the young person has to maintain an integral existence vis-à-vis himself, society and life. Psychology defines the personality as the sum of numerous psychological characteristics, through which differences between people are revealed. The development of these characteristics is to be seen in the environment, maturation and actions of the individual. It can be subdivided into causes, conditions and processes. Finally the article discusses various aspects of the general question of education. The author concludes that the development of the personality should be an aim of education, but that this aim is presently unattainable because of a lack of clarity in the concept of education.

  7. Die Wirtschaftliche Bedeutung von Cyberphysical Systems aus der Sicht Eines Global Players

    NASA Astrophysics Data System (ADS)

    Beetz, Klaus

    Langfristiges und nachhaltiges Denken ist ein wichtiger Teil unserer Tradition. Nachhaltigkeit heißt für uns, in unseren Handlungen die Belange von Ökologie, Ökonomie und sozialer Verantwortung ausgewogen zu berücksichtigen.", sagte Peter Löscher, CEO von Siemens, im Januar 2010.

  8. Materials Data on Ag3AuS2 (SG:166) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  9. Materials Data on Ag3AuSe2 (SG:214) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  10. Probleme bei der Nutzung von Offshore-Wind-energie aus Sicht des Naturschutzes

    NASA Astrophysics Data System (ADS)

    Merck, Thomas; von Nordheim, Henning

    1999-12-01

    Permissions for wind parks of together more than 1000 wind mills have been asked for regarding only the German Exclusive Economical Zone (EEZ) of the North Sea and the Baltic Sea. Following the German Ordinance for Offshore Installations permission cannot be given if flora and fauna will be affected by the installation. Wind energy plants in the offshore area are a new technique and a thorough assessment of their effects on nature is impossible at the moment. Nevertheless, likely and possible effects could be deduced from experiences on land. Thus it has to be expected that roosting, feeding or migrating sea birds will be affected due to disturbance and collision. At least on a local scale the foundations will destroy the benthos but due to their effects on the hydrology and the sedimentation pattern they may change the composition of benthic communities on a larger scale as well. Furthermore they form an artificial hard substrate that serves as habitat for epibenthic flora and fauna not typically found in great parts of the German part of the North Sea. It should be feared that artificial magnetic and electric fields generated by the cable links will affect small and large scale orientation of fishes and marine mammals. Additional disturbances could arise from noise and vibrations released into the water column as well as from the shadows generated by the turning mills. Although these wind parks at least partly will be placed far off-shore a visual disturbance of the landscape has to be expected just as on land. In addition off-shore wind parks will increase the collision risk for ships and accidents may affect areas even far away from the wind park, e.g. by oil spills. In conclusion there is sufficient reason to assume a considerable risk that off-shore wind parks will affect the environment. So far only wind parks consisting of a few mills should be placed. They have to been seen as case studies to enable the necessary research on their effects on nature.

  11. Materials Data on K3AuSe13 (SG:13) by Materials Project

    SciTech Connect

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  12. Zweiwegintegration durch zweisprachige Bildung? Ergebnisse aus der Staatlichen Europa-Schule Berlin

    NASA Astrophysics Data System (ADS)

    Meier, Gabriela

    2012-06-01

    While there is no simple recipe of how to respond to the multitude of languages present in many European schools, this article presents a promising alternative to monolingual education. The focus is on Staatliche Europa-Schule Berlin (SESB), a two-way immersion (TWI) model that unites children whose mother tongue is German with children whose mother tongue is another locally spoken language in one class and teaches them together in two languages. Thus in this model, offered by 17 primary schools and 13 secondary schools in Berlin, pupils learn in two languages from and with each other. Based on a largely quantitative, quasi-experimental study with 603 students, evidence is provided that there are a number of peace-linguistic benefits that can promote two-way social integration, besides fostering personal and societal multilingualism. This suggests that TWI education as practised in Berlin could serve as an educational model for other multilingual parts of Europe.

  13. Syllis onkylochaeta sp. n., ein korallenfressender Polychaet (Syllidae) aus dem Korallenaquarium des Löbbecke-Museums

    NASA Astrophysics Data System (ADS)

    Hartmann-Schröder, Gesa

    1991-03-01

    A new species of the genus Syllis is described feeding on a colony of corals of the genus Xenia (Xeniidae, Alcyonaria) in the coral aquarium of the Löbbecke Museum Düsseldorf. The origin of the corals is very probably Bali (Indonesia).

  14. Stabile Isotope als Tracer zur Bestimmung der Abstandsgeschwindigkeit in Trinkwassergewinnungsbrunnen aus Uferfiltrat

    NASA Astrophysics Data System (ADS)

    van Geldern, Robert; Kolb, Angela; Baier, Alfons; Barth, Johannes A. C.

    2015-09-01

    A potential risk for drinking water wells that gain their water from bank filtration is contamination by pollutants from infiltrating river water. Natural occurring variations in the stable isotope ratio of the river water can be detected in observation wells and drinking water production wells. The flow velocity can then be assessed from the time shift of isotope events and best fit of the measured curves. The determination of the fluid velocity by means of stable isotopes were investigated at a study site in the vicinity of the city Volkach (Bavaria) between the River Main and riverbank drinking water wells. The results revealed a velocity of approx. 2.9 m per day, which results in an average flow time of about 50 days between the river and the drinking water wells. The isotope measurements of this study helped to better constrain earlier estimates of residence times and demonstrated the high potential of this method.

  15. How the nucleus and mitochondria communicate in energy production during stress: nuclear MtATP6, an early-stress responsive gene, regulates the mitochondrial F₁F₀-ATP synthase complex.

    PubMed

    Moghadam, Ali Asghar; Ebrahimie, Eemaeil; Taghavi, Seyed Mohsen; Niazi, Ali; Babgohari, Mahbobeh Zamani; Deihimi, Tahereh; Djavaheri, Mohammad; Ramezani, Amin

    2013-07-01

    A small number of stress-responsive genes, such as those of the mitochondrial F1F0-ATP synthase complex, are encoded by both the nucleus and mitochondria. The regulatory mechanism of these joint products is mysterious. The expression of 6-kDa subunit (MtATP6), a relatively uncharacterized nucleus-encoded subunit of F0 part, was measured during salinity stress in salt-tolerant and salt-sensitive cultivated wheat genotypes, as well as in the wild wheat genotypes, Triticum and Aegilops using qRT-PCR. The MtATP6 expression was suddenly induced 3 h after NaCl treatment in all genotypes, indicating an early inducible stress-responsive behavior. Promoter analysis showed that the MtATP6 promoter includes cis-acting elements such as ABRE, MYC, MYB, GTLs, and W-boxes, suggesting a role for this gene in abscisic acid-mediated signaling, energy metabolism, and stress response. It seems that 6-kDa subunit, as an early response gene and nuclear regulatory factor, translocates to mitochondria and completes the F1F0-ATP synthase complex to enhance ATP production and maintain ion homeostasis under stress conditions. These communications between nucleus and mitochondria are required for inducing mitochondrial responses to stress pathways. Dual targeting of 6-kDa subunit may comprise as a mean of inter-organelle communication and save energy for the cell. Interestingly, MtATP6 showed higher and longer expression in the salt-tolerant wheat and the wild genotypes compared to the salt-sensitive genotype. Apparently, salt-sensitive genotypes have lower ATP production efficiency and weaker energy management than wild genotypes; a stress tolerance mechanism that has not been transferred to cultivated genotypes. PMID:23208548

  16. The molecular motor F-ATP synthase is targeted by the tumoricidal protein HAMLET.

    PubMed

    Ho, James; Sielaff, Hendrik; Nadeem, Aftab; Svanborg, Catharina; Grüber, Gerhard

    2015-05-22

    HAMLET (human alpha-lactalbumin made lethal to tumor cells) interacts with multiple tumor cell compartments, affecting cell morphology, metabolism, proteasome function, chromatin structure and viability. This study investigated if these diverse effects of HAMLET might be caused, in part, by a direct effect on the ATP synthase and a resulting reduction in cellular ATP levels. A dose-dependent reduction in cellular ATP levels was detected in A549 lung carcinoma cells, and by confocal microscopy, co-localization of HAMLET with the nucleotide-binding subunits α (non-catalytic) and β (catalytic) of the energy converting F1F0 ATP synthase was detected. As shown by fluorescence correlation spectroscopy, HAMLET binds to the F1 domain of the F1F0 ATP synthase with a dissociation constant (KD) of 20.5μM. Increasing concentrations of the tumoricidal protein HAMLET added to the enzymatically active α3β3γ complex of the F-ATP synthase lowered its ATPase activity, demonstrating that HAMLET binding to the F-ATP synthase effects the catalysis of this molecular motor. Single-molecule analysis was applied to study HAMLET-α3β3γ complex interaction. Whereas the α3β3γ complex of the F-ATP synthase rotated in a counterclockwise direction with a mean rotational rate of 3.8±0.7s(-1), no rotation could be observed in the presence of bound HAMLET. Our findings suggest that direct effects of HAMLET on the F-ATP synthase may inhibit ATP-dependent cellular processes. PMID:25681694

  17. Pigment Epithelium-derived Factor (PEDF) Binds to Cell-surface F1-ATP Synthase

    PubMed Central

    Notari, Luigi; Arakaki, Naokatu; Mueller, David; Meier, Scott; Amaral, Juan; Becerra, S. Patricia

    2010-01-01

    Pigment epithelium-derived factor (PEDF), a potent blocker of angiogenesis in vivo, and of endothelial cell migration and tubule formation, binds with high affinity to a yet unknown protein on the surface of endothelial cells. Given that protein fingerprinting suggested a match of a ~60-kDa PEDF-binding protein in bovine retina to Bos taurus F1-ATP synthase β-subunit, and that F1F0-ATP synthase components have been identified recently as cell-surface receptors, we examined the direct binding of PEDF to F1. Size-exclusion ultrafiltration assays showed that recombinant human PEDF formed a complex with recombinant yeast F1. Real-time binding by surface plasmon resonance demonstrated that yeast F1 interacted specifically and reversibly with human PEDF. Kinetic evaluations revealed high binding affinity for PEDF, in agreement with PEDF affinities for endothelial cell-surfaces. PEDF blocked interactions between F1 and angiostatin, another antiangiogenic factor, suggesting overlapping PEDF- and angiostatin-binding sites on F1. Surfaces of endothelial cells exhibited affinity for PEDF-binding proteins of ~60-kDa. Antibodies to F1 β-subunit specifically captured PEDF-binding components in endothelial plasma membranes. Extracellular ATP synthesis activity of endothelial cells was examined in the presence of PEDF. PEDF significantly inhibited the extracellular ATP produced by endothelial cells, in agreement with direct interactions between cell-surface ATP synthase and PEDF. In addition to demonstrating that PEDF binds to cell-surface F1, these results show that PEDF is a ligand for endothelial cell-surface F1F0-ATP synthase. They suggest that PEDF-mediated inhibition of ATP synthase may be part of the biochemical mechanisms by which PEDF exerts its antiangiogenic activity. PMID:20412062

  18. Welche Fragen konnen aus einer Gemeinsamen Interpretation der Befunde aus PISA and IGLU Fundiert Beantwortet Werden? (To Which Questions Does a Combined Interpretation of the Results Yielded by both PISA and IGLU Provide Well-Grounded Answers?).

    ERIC Educational Resources Information Center

    Bos, Wilfried; Lankes, Eva-Maria; Prenzel, Manfred; Schwippert, Knut; Walther, Gerd; Valtin, Renate; Voss, Andreas

    2003-01-01

    Discusses the International Survey on Reading Abilities in Primary School (IGLU) and its data on achievement in reading, mathematics, and natural science. Compares this data to that collected by the Program for International Student Assessment (PISA). Identifies achievement relevant correlations such as gender, migration background, socioeconomic…

  19. Die Bewertung von Textaufgaben - dargestellt an Beispielen aus dem Franzoesischunterricht (Grading Textbook Lessons -- Presented with Examples from Teaching French)

    ERIC Educational Resources Information Center

    Edener, Wilfried

    1975-01-01

    Explains and illustrates the term "textbook lesson," and mentions the considerations that have led to the recommended grading system. The chief aim is to achieve uniformity in grading. Offers recommendations for formulating and ordering lessons, grading criteria, awarding of points and key for computing points. (Text is in German.) (IFS/WGA)

  20. Elucidation of the Au-S bond in a passivated gold cluster through density functional theory calculations (abstract only).

    PubMed

    Sihelniková, L; Tvaroška, I

    2008-02-13

    Gold clusters are of increasing interest due to a number of already established as well as new potential applications in different fields of nanotechnology. The use of gold nanoparticles can be significantly extended by surface modifications, sulfidation being the most popular. The identifications of preferred adsorption geometries, bond formation, and binding energies are helpful tools for understanding the properties of these particles. This study is focused on a 38-atom gold cluster passivated with 3-hydroxypropanthiolate linkers. Starting from the re-optimized global minimum structure of a bare 38-atom gold cluster (Doye and Wales 1998 New J. Chem. 22 733-44) and aiming at a description of the passivated particle, density functional theory calculations (within the framework of the Amsterdam density functional calculation package ADF 2006.01 (ADF2006.01, SCM, Theoretical Chemistry, Vrije Universiteit, Amsterdam, The Netherlands, http://www.scm.com)) were performed at the level of the generalized gradient approximation of Perdew and Wang from 1991, with triple-zeta Slater basis sets plus p- and f-polarization functions (TZ2P) for the 33 outermost electrons of each gold atom, and considering scalar relativistic effects. Using this methodology, the space around the gold cluster (with the distance of the S of the thiolate from the gold cluster surface in the range 2.3-2.6 Å) was examined to identify the most favourable absorption site for the thiolate linker. As a result, a 3D map was created and low energy areas corresponding to the potentially most favourable site for one 3-hydroxypropanthiolate linker on the gold cluster localized. Structures representing these areas were further optimized and consequently analysed using Mulliken population analysis to compare charge distribution over the tested structures, Mayer bond order analysis, as well as electron localization function/indicator bond formation analysis. The results obtained will be presented in comparison to ones available from studies of other research groups. PMID:21693876

  1. Bienvenue aus Etats-Unis. Guide Pour Refugies. (Welcome to the United States. A Guidebook for Refugees).

    ERIC Educational Resources Information Center

    Center for Applied Linguistics, Washington, DC. Refugee Service Center.

    This guidebook provides French-speaking refugees being resettled in the United States with general information about what they will encounter and the services they can receive in their first months in the country. The book is distributed to overseas processing agencies, refugees overseas who have been approved for U.S. admission, and service…

  2. Grundwassergefährdungspotenzial von Additiven in Wärmeträgerflüssigkeiten aus Erdwärmesonden

    NASA Astrophysics Data System (ADS)

    Ilieva, Dafina; Haderlein, Stefan B.; Morasch, Barbara

    2014-12-01

    The number of installed vertical borehole heat exchangers is continuing to grow continuously which increases the risk of a local groundwater contamination with heat exchanger fluids due to a system leakage. This study evaluates the groundwater pollution potential of organic additives applied in heat exchanger fluids. In the first step of the project a data survey was carried out to collect detailed information about the identity, frequency of use and concentrations of the applied additives. In total, 35 different additives were disclosed by producers and/or distributors of heat exchanger fluids. The additives were classified as corrosion inhibitors, alkalis, dyes, solvents, scentsflavours, defoamers, and surfactants. The groundwater pollution potential of the additives was assessed based on their frequency of usage in the declared fluids and on their environmental fate (mobility, persistence and aquatic toxicity). Based on our analysis, the corrosion inhibitors benzotriazole, tolyltriazole, 2-ethylhexanoate, benzoate and sebacate exhibit a potentially exhibit a significant risk for groundwater contamination.

  3. Grundwassergefährdungspotenzial von Additiven in Wärmeträgerflüssigkeiten aus Erdwärmesonden

    NASA Astrophysics Data System (ADS)

    Ilieva, Dafina; Haderlein, Stefan B.; Morasch, Barbara

    2014-09-01

    The number of installed vertical borehole heat exchangers is continuing to grow continuously which increases the risk of a local groundwater contamination with heat exchanger fluids due to a system leakage. This study evaluates the groundwater pollution potential of organic additives applied in heat exchanger fluids. In the first step of the project a data survey was carried out to collect detailed information about the identity, frequency of use and concentrations of the applied additives. In total, 35 different additives were disclosed by producers and/or distributors of heat exchanger fluids. The additives were classified as corrosion inhibitors, alkalis, dyes, solvents, scentsflavours, defoamers, and surfactants. The groundwater pollution potential of the additives was assessed based on their frequency of usage in the declared fluids and on their environmental fate (mobility, persistence and aquatic toxicity). Based on our analysis, the corrosion inhibitors benzotriazole, tolyltriazole, 2-ethylhexanoate, benzoate and sebacate exhibit a potentially exhibit a significant risk for groundwater contamination.

  4. Direkte Kontakte zu Deutschland aus und in der Ferne (Direct Contact with Germany from and at a Distance).

    ERIC Educational Resources Information Center

    Wicke, Rainer E.

    This guide is a summary of ideas for enhancing the teaching of German through direct contact with Germany or German people without traveling abroad. The following ideas are highlighted: (1) correspondence (pen pals) with students in Germany; (2) audiotape recordings as an alternative to letter writing; (3) the exchange of videotape recordings with…

  5. An obituary of Christoph Scheiner from the year 1650. (German Title: Ein Nachruf auf Christoph Scheiner aus dem Jahr 1650)

    NASA Astrophysics Data System (ADS)

    Daxecker, Franz; Schaffenrath, Florian

    An obituary of the astronomer and Jesuit Christoph Scheiner (1573-1650) was discovered in Cracow in the year 2001. This discovery makes it now possible to fix Scheiner's year of birth to 1573. Scheiner had a controversy with Galileo Galilei about the priority of the discovery of sunspots. Scheiner remained a supporter of the geocentric system until his death in 1650. The obituary gives new insights into Scheiner's personality and the last years of his life.

  6. Utopie: Eine Geschichte aus dem 15. Jahrhundert fur die Siebte Klasse, mit Ubungen (Utopia: A View of the 15th Century for the Seventh Class, with Exercises).

    ERIC Educational Resources Information Center

    Stott, Michael

    This German language textbook is intended for classroom use. The theme of the text relates to the Renaissance, and the narrative is based on Sir Thomas More's "Utopia" (1516) and relates to the experiences of its central character Raphael among the inhabitants of the strange island. Each chapter touches lightly on some thought provoking issue,…

  7. Philippus Feselius - Biographical notes on the unknown medicus of Kepler's Tertius Interveniens. (German Title: Philippus Feselius - Biographische Notizen zum unbekannten Medicus aus Keplers Tertius Interveniens)

    NASA Astrophysics Data System (ADS)

    Lenke, Nils; Roudet, Nicolas

    Until now, Philipp Feselius has been perceived only indirectly as Kepler's antagonist. Not much is known about his life besides his work as Baden private physician and his book against astrology which was cited intensely in Kepler's «Tertius Interveniens». This paper traces the stations of his career as a physician, about his presumable provenance and education in Strasbourg, his academic career in Tübingen, Strasbourg, Rostock and Padua, the doctorate in Basel in 1592, up to his employment, in 1599, as a court physician in Sulzburg and later in Durlach. Further hand-written and printed traces of Feselius are presented, and his social environment is investigated so that his personality becomes clearer, and relations can be established between his education and his writing against astrology.

  8. ASAS 095221-4329.8 und ASAS 123034-7703.9 - zwei R-CrB-Stern-Kandidaten aus der ASAS-Datenbank

    NASA Astrophysics Data System (ADS)

    Huemmerich, Stefan

    2011-04-01

    During an examination of ASAS Misc-type objects, the stars ASAS 095221-4329.8 GSC 07706-00560, 09:52:21.38 -43:29:40.5) and ASAS 123034-7703.9 (GSC 09416-00380, 12:30:34.22 -77:03:52.7) - both of which show semi-regular variability - were found to exhibit significant obscuration events in their V-band lightcurves. Both stars are likely to be red giants undergoing fading events, possibly of DY Per-type. However, spectroscopy of both stars is needed for a conclusive classification. The corresponding entries in the International Variable Star Index (VSX) have been revised accordingly; variability type was set to "RCB:".

  9. Bildung in der Strukturr Sozio-ökonomischer Entwicklung: Eine Analyse von Löngsschnittsdaten aus Afrika südlich der Sahara

    NASA Astrophysics Data System (ADS)

    Bergmann, Herbert

    1991-06-01

    The preparation for the World Conference on Education for All at the beginning of 1990 once again showed clearly the importance of education for development in the countries of the Third World. This article explores the systemic place of education in the process of development. With the help of factor analysis it treats the following individual questions: Is education, or basic education, an independent factor? Are the many development indicators determined by general factors? Is basic education one of these factors? An analysis is made of development indicators from 1960 to 1984 drawn from World Bank reports on 38 sub-Saharan African countries. Two sets of economic, demographic and educational data have been examined: the first relates to the year 1984 (or nearest available); the second contains two years, adding an earlier set from the nearest available date to 1960. The analysis of the later set reveals five factors: general modernization, population growth, economic development, pupil-teacher ratio, and food supply to the general population. Education is not an independent factor in this list. Using the data sets from both years, seven factors are revealed. After diagonal rotation these are: basic education, degree of urbanization, pupil-teacher ratio, average standard of living attained, economic growth, service sector, food production per head, population growth, and employment in modern sectors.

  10. A review of the Australian-New Zealand sector of the Southern Ocean over the last 30 ka (Aus-INTIMATE project)

    NASA Astrophysics Data System (ADS)

    Bostock, H. C.; Barrows, T. T.; Carter, L.; Chase, Z.; Cortese, G.; Dunbar, G. B.; Ellwood, M.; Hayward, B.; Howard, W.; Neil, H. L.; Noble, T. L.; Mackintosh, A.; Moss, P. T.; Moy, A. D.; White, D.; Williams, M. J. M.; Armand, L. K.

    2013-08-01

    The Australia/New Zealand region of the Southern Ocean is influenced by several of the major global water masses of the oceans and is the prime entry point for cold deep waters into the Pacific basin. During the last glacial there was increased sea-ice extent around Antarctica (as far north as 55°S), as well as increased iceberg presence inferred from ice-rafted debris. Evidence from microfossil assemblages suggests that sea surface temperatures (SST) were up to 7 °C cooler, consistent with recent estimates of cooling for New Zealand derived from glacier modelling and other terrestrial proxies. The Subtropical Front (STF), Subantarctic Front (SAF) and Polar Front (PF) had migrated north, except where the position of the fronts were controlled bathymetrically. Despite the potential for iron fertilisation by increased dust input into the ocean during the glacial, there is limited evidence for higher total biological productivity in the Pacific sector of the Southern Ocean. The altered oceanic circulation during the glacial also decreased nutrients in the surface waters and affected the outgassing of CO2. This contributed to an increased storage of CO2 in the deep waters and lowering of the carbonate lysocline. During the deglaciation, sea-ice retreat and SST increased rapidly at ˜18 ka, roughly synchronous with the reinvigoration of deep water circulation in the Southern Ocean and the release of CO2 stored in the deep waters. The gradient in carbon isotopes (δ13Cbenthic) between Antarctic Intermediate Water (AAIW) and lower Circumpolar Deep Water (LCDW) was greatest at the start of the deglaciation, suggesting that the AAIW ventilation preceded LCDW ventilation, or there was a significant change in air-sea fractionation of δ13C. There was a slight enrichment in δ18Oplanktic, decrease in SSTs and a reduction in intermediate and deep water circulation between ˜14 and 12.5 ka BP during the Antarctic Cold Reversal (ACR), coincident with glacier advances in the New Zealand Southern Alps and other terrestrial records of cooling. Following the ACR, there was a second, more minor, release of deep water CO2, most likely related to reinvigoration of North Atlantic Deep Water (NADW). From 10 ka onwards the modern intermediate and deep water circulation was established. Air temperatures and SSTs reached a maximum in the early Holocene, with the STF located at its most southerly position, and there was a widespread retreat of Antarctic ice sheets to their modern position. A decline to modern SST and air temperatures in the mid to late Holocene followed. While millennial cycles overprinted on the SST and δ18Oplanktic records, may be the result of subtle changes in the position and strength of the westerly winds during the Holocene.

  11. Mimicking respiratory phosphorylation using purified enzymes.

    PubMed

    von Ballmoos, Christoph; Biner, Olivier; Nilsson, Tobias; Brzezinski, Peter

    2016-04-01

    The enzymes of oxidative phosphorylation is a striking example of the functional association of multiple enzyme complexes, working together to form ATP from cellular reducing equivalents. These complexes, such as cytochrome c oxidase or the ATP synthase, are typically investigated individually and therefore, their functional interplay is not well understood. Here, we present methodology that allows the co-reconstitution of purified terminal oxidases and ATP synthases in synthetic liposomes. The enzymes are functionally coupled via proton translocation where upon addition of reducing equivalents the oxidase creates and maintains a transmembrane electrochemical proton gradient that energizes the synthesis of ATP by the F1F0 ATP synthase. The method has been tested with the ATP synthases from Escherichia coli and spinach chloroplasts, and with the quinol and cytochrome c oxidases from E. coli and Rhodobacter sphaeroides, respectively. Unlike in experiments with the ATP synthase reconstituted alone, the setup allows in vitro ATP synthesis under steady state conditions, with rates up to 90 ATP×s(-1)×enzyme(-1). We have also used the novel system to study the phenomenon of "mild uncoupling" as observed in mitochondria upon addition of low concentrations of ionophores (e.g. FCCP, SF6847) and the recoupling effect of 6-ketocholestanol. While we could reproduce the described effects, our data with the in vitro system does not support the idea of a direct interaction between a mitochondrial protein and the uncoupling agents as proposed earlier. PMID:26707617

  12. F1 rotary motor of ATP synthase is driven by the torsionally-asymmetric drive shaft

    PubMed Central

    Kulish, O.; Wright, A. D.; Terentjev, E. M.

    2016-01-01

    F1F0 ATP synthase (ATPase) either facilitates the synthesis of ATP in a process driven by the proton moving force (pmf), or uses the energy from ATP hydrolysis to pump protons against the concentration gradient across the membrane. ATPase is composed of two rotary motors, F0 and F1, which compete for control of their shared γ -shaft. We present a self-consistent physical model of F1 motor as a simplified two-state Brownian ratchet using the asymmetry of torsional elastic energy of the coiled-coil γ -shaft. This stochastic model unifies the physical concepts of linear and rotary motors, and explains the stepped unidirectional rotary motion. Substituting the model parameters, all independently known from recent experiments, our model quantitatively reproduces the ATPase operation, e.g. the ‘no-load’ angular velocity is ca. 400 rad/s anticlockwise at 4 mM ATP. Increasing the pmf torque exerted by F0 can slow, stop and overcome the torque generated by F1, switching from ATP hydrolysis to synthesis at a very low value of ‘stall torque’. We discuss the motor efficiency, which is very low if calculated from the useful mechanical work it produces - but is quite high when the ‘useful outcome’ is measured in the number of H+ pushed against the chemical gradient. PMID:27321713

  13. An analysis of the effects of Mn{sup 2+} on oxidative phosphorylation in liver, brain, and heart mitochondria using state 3 oxidation rate assays

    SciTech Connect

    Gunter, Thomas E.; Gerstner, Brent; Lester, Tobias; Wojtovich, Andrew P.; Malecki, Jon; Swarts, Steven G.; Brookes, Paul S.; Gavin, Claire E. Gunter, Karlene K.

    2010-11-15

    Manganese (Mn) toxicity is partially mediated by reduced ATP production. We have used oxidation rate assays-a measure of ATP production-under rapid phosphorylation conditions to explore sites of Mn{sup 2+} inhibition of ATP production in isolated liver, brain, and heart mitochondria. This approach has several advantages. First, the target tissue for Mn toxicity in the basal ganglia is energetically active and should be studied under rapid phosphorylation conditions. Second, Mn may inhibit metabolic steps which do not affect ATP production rate. This approach allows identification of inhibitions that decrease this rate. Third, mitochondria from different tissues contain different amounts of the components of the metabolic pathways potentially resulting in different patterns of ATP inhibition. Our results indicate that Mn{sup 2+} inhibits ATP production with very different patterns in liver, brain, and heart mitochondria. The primary Mn{sup 2+} inhibition site in liver and heart mitochondria, but not in brain mitochondria, is the F{sub 1}F{sub 0} ATP synthase. In mitochondria fueled by either succinate or glutamate + malate, ATP production is much more strongly inhibited in brain than in liver or heart mitochondria; moreover, Mn{sup 2+} inhibits two independent sites in brain mitochondria. The primary site of Mn-induced inhibition of ATP production in brain mitochondria when succinate is substrate is either fumarase or complex II, while the likely site of the primary inhibition when glutamate plus malate are the substrates is either the glutamate/aspartate exchanger or aspartate aminotransferase.

  14. Genome-guided analysis of physiological capacities of Tepidanaerobacter acetatoxydans provides insights into environmental adaptations and syntrophic acetate oxidation.

    PubMed

    Müller, Bettina; Manzoor, Shahid; Niazi, Adnan; Bongcam-Rudloff, Erik; Schnürer, Anna

    2015-01-01

    This paper describes the genome-based analysis of Tepidanaerobacter acetatoxydans strain Re1, a syntrophic acetate-oxidising bacterium (SAOB). Principal issues such as environmental adaptations, metabolic capacities, and energy conserving systems have been investigated and the potential consequences for syntrophic acetate oxidation discussed. Briefly, in pure culture, T. acetatoxydans grows with different organic compounds and produces acetate as the main product. In a syntrophic consortium with a hydrogenotrophic methanogen, it can also reverse its metabolism and instead convert acetate to formate/H2 and CO2. It can only proceed if the product formed is continuously removed. This process generates a very small amount of energy that is scarcely enough for growth, which makes this particular syntrophy of special interest. As a crucial member of the biogas-producing community in ammonium-rich engineered AD processes, genomic features conferring ammonium resistance, bacterial defense, oxygen and temperature tolerance were found, as well as attributes related to biofilm formation and flocculation. It is likely that T. acetatoxydans can form an electrochemical gradient by putative electron-bifurcating Rnf complex and [Fe-Fe] hydrogenases, as observed in other acetogens. However, genomic deficiencies related to acetogenic metabolism and anaerobic respiration were discovered, such as the lack of formate dehydrogenase and F1F0 ATP synthase. This has potential consequences for the metabolic pathways used under SAO and non-SAO conditions. The two complete sets of bacteriophage genomes, which were found to be encoded in the genome, are also worthy of mention. PMID:25811859

  15. Aim-less translation: loss of Saccharomyces cerevisiae mitochondrial translation initiation factor mIF3/Aim23 leads to unbalanced protein synthesis

    PubMed Central

    Kuzmenko, Anton; Derbikova, Ksenia; Salvatori, Roger; Tankov, Stoyan; Atkinson, Gemma C.; Tenson, Tanel; Ott, Martin; Kamenski, Piotr; Hauryliuk, Vasili

    2016-01-01

    The mitochondrial genome almost exclusively encodes a handful of transmembrane constituents of the oxidative phosphorylation (OXPHOS) system. Coordinated expression of these genes ensures the correct stoichiometry of the system’s components. Translation initiation in mitochondria is assisted by two general initiation factors mIF2 and mIF3, orthologues of which in bacteria are indispensible for protein synthesis and viability. mIF3 was thought to be absent in Saccharomyces cerevisiae until we recently identified mitochondrial protein Aim23 as the missing orthologue. Here we show that, surprisingly, loss of mIF3/Aim23 in S. cerevisiae does not indiscriminately abrogate mitochondrial translation but rather causes an imbalance in protein production: the rate of synthesis of the Atp9 subunit of F1F0 ATP synthase (complex V) is increased, while expression of Cox1, Cox2 and Cox3 subunits of cytochrome c oxidase (complex IV) is repressed. Our results provide one more example of deviation of mitochondrial translation from its bacterial origins. PMID:26728900

  16. Mechanisms of ATP release and signalling in the blood vessel wall

    PubMed Central

    Lohman, Alexander W.; Billaud, Marie; Isakson, Brant E.

    2012-01-01

    The nucleotide adenosine 5′-triphosphate (ATP) has classically been considered the cell's primary energy currency. Importantly, a novel role for ATP as an extracellular autocrine and/or paracrine signalling molecule has evolved over the past century and extensive work has been conducted to characterize the ATP-sensitive purinergic receptors expressed on almost all cell types in the body. Extracellular ATP elicits potent effects on vascular cells to regulate blood vessel tone but can also be involved in vascular pathologies such as atherosclerosis. While the effects of purinergic signalling in the vasculature have been well documented, the mechanism(s) mediating the regulated release of ATP from cells in the blood vessel wall and circulation are now a key target of investigation. The aim of this review is to examine the current proposed mechanisms of ATP release from vascular cells, with a special emphasis on the transporters and channels involved in ATP release from vascular smooth muscle cells, endothelial cells, circulating red blood cells, and perivascular sympathetic nerves, including vesicular exocytosis, plasma membrane F1/F0-ATP synthase, ATP-binding cassette (ABC) transporters, connexin hemichannels, and pannexin channels. PMID:22678409

  17. Genome-Guided Analysis of Physiological Capacities of Tepidanaerobacter acetatoxydans Provides Insights into Environmental Adaptations and Syntrophic Acetate Oxidation

    PubMed Central

    Niazi, Adnan; Bongcam-Rudloff, Erik; Schnürer, Anna

    2015-01-01

    This paper describes the genome-based analysis of Tepidanaerobacter acetatoxydans strain Re1, a syntrophic acetate-oxidising bacterium (SAOB). Principal issues such as environmental adaptations, metabolic capacities, and energy conserving systems have been investigated and the potential consequences for syntrophic acetate oxidation discussed. Briefly, in pure culture, T. acetatoxydans grows with different organic compounds and produces acetate as the main product. In a syntrophic consortium with a hydrogenotrophic methanogen, it can also reverse its metabolism and instead convert acetate to formate/H2 and CO2. It can only proceed if the product formed is continuously removed. This process generates a very small amount of energy that is scarcely enough for growth, which makes this particular syntrophy of special interest. As a crucial member of the biogas-producing community in ammonium-rich engineered AD processes, genomic features conferring ammonium resistance, bacterial defense, oxygen and temperature tolerance were found, as well as attributes related to biofilm formation and flocculation. It is likely that T. acetatoxydans can form an electrochemical gradient by putative electron-bifurcating Rnf complex and [Fe-Fe] hydrogenases, as observed in other acetogens. However, genomic deficiencies related to acetogenic metabolism and anaerobic respiration were discovered, such as the lack of formate dehydrogenase and F1F0 ATP synthase. This has potential consequences for the metabolic pathways used under SAO and non-SAO conditions. The two complete sets of bacteriophage genomes, which were found to be encoded in the genome, are also worthy of mention. PMID:25811859

  18. Cloning of the cDNA for the human ATP synthase OSCP subunit (ATP5O) by exon trapping and mapping to chromosome 21q22.1-q22.2

    SciTech Connect

    Chen, Haiming; Morris, M.A.; Rossier, C.

    1995-08-10

    Exon trapping was used to clone portions of potential genes from human chromosome 21. One trapped sequence showed striking homology with the bovine and rat ATP synthase OSCP (oligomycin sensitivity conferring protein) subunit. We subsequently cloned the full-length human ATP synthase OSCP cDNA (GDB/HGMW approved name ATP50) from infant brain and muscle libraries and determined its nucleotide and deduced amino acid sequence (EMBL/GenBank Accession No. X83218). The encoded polypeptide contains 213 amino acids, with more than 80% identity to bovine and murine ATPase OSCP subunits and over 35% identity to Saccharomyces cerevisiae and sweet potato sequences. The human ATP5O gene is located at 21q22.1-q22.2, just proximal to D21S17, in YACs 860G11 and 838C7 of the Chumakov et al. YAC contig. The gene is expressed in all human tissues examined, most strongly in muscle and heart. This ATP5O subunit is a key structural component of the stalk of the mitochondrial respiratory chain F{sub 1}F{sub 0}-ATP synthase and as such may contribute in a gene dosage-dependent manner to the phenotype of Down syndrome (trisomy 21). 39 refs., 5 figs.

  19. The alpha-subunit of Leishmania F1 ATP synthase hydrolyzes ATP in presence of tRNA.

    PubMed

    Goswami, Srikanta; Adhya, Samit

    2006-07-14

    Import of tRNAs into the mitochondria of the kinetoplastid protozoon Leishmania requires the tRNA-dependent hydrolysis of ATP leading to the generation of membrane potential through the pumping of protons. Subunit RIC1 of the inner membrane RNA import complex is a bi-functional protein that is identical to the alpha-subunit of F1F0 ATP synthase and specifically binds to a subset (Type I) of importable tRNAs. We show that recombinant, purified RIC1 is a Type I tRNA-dependent ATP hydrolase. The activity was insensitive to oligomycin, sensitive to mutations within the import signal of the tRNA, and required the cooperative interaction between the ATP-binding and C-terminal domains of RIC1. The ATPase activity of the intact complex was inhibited by anti-RIC1 antibody, while knockdown of RIC1 in Leishmania tropica resulted in deficiency of the tRNA-dependent ATPase activity of the mitochondrial inner membrane. Moreover, RIC1 knockdown extracts failed to generate a membrane potential across reconstituted proteoliposomes, as shown by a rhodamine 123 uptake assay, but activity was restored by adding back purified RIC1. These observations identify RIC1 as a novel form of the F1 ATP synthase alpha-subunit that acts as the major energy transducer for tRNA import. PMID:16735512

  20. Biochemical investigation of a human pathogenic mutation in the nuclear ATP5E gene using yeast as a model

    PubMed Central

    Sardin, Elodie; Donadello, Stéphanie; di Rago, Jean-Paul; Tetaud, Emmanuel

    2015-01-01

    F1F0-ATP synthase is a key enzyme of the mitochondrial energetic metabolism responsible for the production of most cellular ATP in humans. Mayr et al. (2010) recently described a patient with a homozygote (Y12C) mutation in the nuclear gene ATP5E encoding the ε-subunit of ATP synthase. To better define how it affects ATP synthase, we have modeled this mutation in the yeast Saccharomyces cerevisiae. A yeast equivalent of this mutation (Y11C) had no significant effect on the growth of yeast on non-fermentable carbon sources (glycerol/ethanol or lactate), conditions under which the activity of the mitochondrial energy transducing system is absolutely essential. In addition, similar to what was observed in patient, this mutation in yeast has a minimal effect on the ATPase/synthase activities. On the contrary, this mutation which has been shown to have a strong impact on the assembly of the ATP synthase complex in humans, shows no significant impact on the assembly/stability of this complex in yeast, suggesting that biogenesis of this complex differs significantly. PMID:25954304

  1. Mitochondrial functions of RECQL4 are required for the prevention of aerobic glycolysis-dependent cell invasion.

    PubMed

    Kumari, Jyoti; Hussain, Mansoor; De, Siddharth; Chandra, Suruchika; Modi, Priyanka; Tikoo, Shweta; Singh, Archana; Sagar, Chandrasekhar; Sepuri, Naresh Babu V; Sengupta, Sagar

    2016-04-01

    Germline mutations in RECQL4 helicase are associated with Rothmund-Thomson syndrome, which is characterized by a predisposition to cancer. RECQL4 localizes to the mitochondria, where it acts as an accessory factor during mitochondrial DNA replication. To understand the specific mitochondrial functions of RECQL4, we created isogenic cell lines, in which the mitochondrial localization of the helicase was either retained or abolished. The mitochondrial integrity was affected due to the absence of RECQL4 in mitochondria, leading to a decrease in F1F0-ATP synthase activity. In cells where RECQL4 does not localize to mitochondria, the membrane potential was decreased, whereas ROS levels increased due to the presence of high levels of catalytically inactive SOD2. Inactive SOD2 accumulated owing to diminished SIRT3 activity. Lack of the mitochondrial functions of RECQL4 led to aerobic glycolysis that, in turn, led to an increased invasive capability within these cells. Together, this study demonstrates for the first time that, owing to its mitochondrial functions, the accessory mitochondrial replication helicase RECQL4 prevents the invasive step in the neoplastic transformation process. PMID:26906415

  2. Mitochondrial Efficiency-Dependent Viability of Saccharomyces cerevisiae Mutants Carrying Individual Electron Transport Chain Component Deletions.

    PubMed

    Kwon, Young-Yon; Choi, Kyung-Mi; Cho, ChangYeon; Lee, Cheol-Koo

    2015-12-31

    Mitochondria play a crucial role in eukaryotic cells; the mitochondrial electron transport chain (ETC) generates adenosine triphosphate (ATP), which serves as an energy source for numerous critical cellular activities. However, the ETC also generates deleterious reactive oxygen species (ROS) as a natural byproduct of oxidative phosphorylation. ROS are considered the major cause of aging because they damage proteins, lipids, and DNA by oxidation. We analyzed the chronological life span, growth phenotype, mitochondrial membrane potential (MMP), and intracellular ATP and mitochondrial superoxide levels of 33 single ETC component-deleted strains during the chronological aging process. Among the ETC mutant strains, 14 (sdh1Δ, sdh2Δ, sdh4Δ, cor1Δ, cyt1Δ, qcr7Δ, qcr8Δ, rip1Δ, cox6Δ, cox7Δ, cox9Δ, atp4Δ, atp7Δ, and atp17Δ) showed a significantly shorter life span. The deleted genes encode important elements of the ETC components succinate dehydrogenase (complex II) and cytochrome c oxidase (complex IV), and some of the deletions lead to structural instability of the membrane-F1F0-ATP synthase due to mutations in the stator stalk (complex V). These short-lived strains generated higher superoxide levels and produced lower ATP levels without alteration of MMP. In summary, ETC mutations decreased the life span of yeast due to impaired mitochondrial efficiency. PMID:26608359

  3. UCP2 regulates energy metabolism and differentiation potential of human pluripotent stem cells

    PubMed Central

    Zhang, Jin; Khvorostov, Ivan; Hong, Jason S; Oktay, Yavuz; Vergnes, Laurent; Nuebel, Esther; Wahjudi, Paulin N; Setoguchi, Kiyoko; Wang, Geng; Do, Anna; Jung, Hea-Jin; McCaffery, J Michael; Kurland, Irwin J; Reue, Karen; Lee, Wai-Nang P; Koehler, Carla M; Teitell, Michael A

    2011-01-01

    It has been assumed, based largely on morphologic evidence, that human pluripotent stem cells (hPSCs) contain underdeveloped, bioenergetically inactive mitochondria. In contrast, differentiated cells harbour a branched mitochondrial network with oxidative phosphorylation as the main energy source. A role for mitochondria in hPSC bioenergetics and in cell differentiation therefore remains uncertain. Here, we show that hPSCs have functional respiratory complexes that are able to consume O2 at maximal capacity. Despite this, ATP generation in hPSCs is mainly by glycolysis and ATP is consumed by the F1F0 ATP synthase to partially maintain hPSC mitochondrial membrane potential and cell viability. Uncoupling protein 2 (UCP2) plays a regulating role in hPSC energy metabolism by preventing mitochondrial glucose oxidation and facilitating glycolysis via a substrate shunting mechanism. With early differentiation, hPSC proliferation slows, energy metabolism decreases, and UCP2 is repressed, resulting in decreased glycolysis and maintained or increased mitochondrial glucose oxidation. Ectopic UCP2 expression perturbs this metabolic transition and impairs hPSC differentiation. Overall, hPSCs contain active mitochondria and require UCP2 repression for full differentiation potential. PMID:22085932

  4. F1 rotary motor of ATP synthase is driven by the torsionally-asymmetric drive shaft

    NASA Astrophysics Data System (ADS)

    Kulish, O.; Wright, A. D.; Terentjev, E. M.

    2016-06-01

    F1F0 ATP synthase (ATPase) either facilitates the synthesis of ATP in a process driven by the proton moving force (pmf), or uses the energy from ATP hydrolysis to pump protons against the concentration gradient across the membrane. ATPase is composed of two rotary motors, F0 and F1, which compete for control of their shared γ -shaft. We present a self-consistent physical model of F1 motor as a simplified two-state Brownian ratchet using the asymmetry of torsional elastic energy of the coiled-coil γ -shaft. This stochastic model unifies the physical concepts of linear and rotary motors, and explains the stepped unidirectional rotary motion. Substituting the model parameters, all independently known from recent experiments, our model quantitatively reproduces the ATPase operation, e.g. the ‘no-load’ angular velocity is ca. 400 rad/s anticlockwise at 4 mM ATP. Increasing the pmf torque exerted by F0 can slow, stop and overcome the torque generated by F1, switching from ATP hydrolysis to synthesis at a very low value of ‘stall torque’. We discuss the motor efficiency, which is very low if calculated from the useful mechanical work it produces - but is quite high when the ‘useful outcome’ is measured in the number of H+ pushed against the chemical gradient.

  5. F1 rotary motor of ATP synthase is driven by the torsionally-asymmetric drive shaft.

    PubMed

    Kulish, O; Wright, A D; Terentjev, E M

    2016-01-01

    F1F0 ATP synthase (ATPase) either facilitates the synthesis of ATP in a process driven by the proton moving force (pmf), or uses the energy from ATP hydrolysis to pump protons against the concentration gradient across the membrane. ATPase is composed of two rotary motors, F0 and F1, which compete for control of their shared γ -shaft. We present a self-consistent physical model of F1 motor as a simplified two-state Brownian ratchet using the asymmetry of torsional elastic energy of the coiled-coil γ -shaft. This stochastic model unifies the physical concepts of linear and rotary motors, and explains the stepped unidirectional rotary motion. Substituting the model parameters, all independently known from recent experiments, our model quantitatively reproduces the ATPase operation, e.g. the 'no-load' angular velocity is ca. 400 rad/s anticlockwise at 4 mM ATP. Increasing the pmf torque exerted by F0 can slow, stop and overcome the torque generated by F1, switching from ATP hydrolysis to synthesis at a very low value of 'stall torque'. We discuss the motor efficiency, which is very low if calculated from the useful mechanical work it produces - but is quite high when the 'useful outcome' is measured in the number of H(+) pushed against the chemical gradient. PMID:27321713

  6. Nature of plant stimulators in the production of Acetobacter xylinum ({open_quotes}Tea fungas{close_quotes}) biofilm used in skin therapy

    SciTech Connect

    Fontana, J.D.; Franco, V.C.; Lyra, I.N.; De Souza, A.M.; De Souza, S.

    1991-12-31

    Caffeine and related xanthines were identified as potent stimulators for the bacterial cellulose production in A. xylinum. These compounds are present in several plants whose infusions are useful as culture-medium supplements for this acetobacterium. The proposed target for these native purine-like inhibitory substances is the novel diguanyl nucleotide phosphodiesterase(s) that participates in the bacterial cellulogenic complex.

  7. Growth-substrate dependent dechlorination of 1,2-dichloroethane by a homoacetogenic bacterium.

    PubMed

    De Wildeman, Stefaan; Neumann, Anke; Diekert, Gabriele; Verstraete, Willy

    2003-08-01

    A rod shaped, gram positive, non sporulating Acetobacterium strain was isolated that dechlorinated 1,2dichloroethane (1,2-DCA) to ethene at a dechlorination rate of up to 2 nmol Cl- min(-1) mg(-1) of protein in the exponential growth phase with formate (40 mM) as the substrate. Although with other growth substrates such as pyruvate, lactate, H2/CO2, and ethanol higher biomass productions were obtained, the dechlorination rate with these substrates was more than 10-fold lower compared with formate growing cells. Neither cell extracts nor autoclaved cells of the isolated Acetobacterium strain mediated the dechlorination of 1,2-DCA at significant rates. The addition of 1,2-DCA to the media did not result in increased cell production. No significant differences in corrinoid concentrations could be measured in cells growing on several growth-substrates. However, these measurements indicated that differences in corrinoid structure might cause the different dechlorination activity. The Acetobacterium sp. strain gradually lost its dechlorination ability during about 10 transfers in pure culture, probably due to undefined nutritional requirements. 16S rDNA analysis of the isolate revealed a 99.7% similarity with Acetobacterium wieringae. However, the type strains of A. wieringae and A. woodii did not dechlorinate 1,2-DCA. PMID:12948054

  8. Regulation of necrotic cell death: p53, PARP1 and cyclophilin D-overlapping pathways of regulated necrosis?

    PubMed

    Ying, Yuan; Padanilam, Babu J

    2016-06-01

    In contrast to apoptosis and autophagy, necrotic cell death was considered to be a random, passive cell death without definable mediators. However, this dogma has been challenged by recent developments suggesting that necrotic cell death can also be a regulated process. Regulated necrosis includes multiple cell death modalities such as necroptosis, parthanatos, ferroptosis, pyroptosis, and mitochondrial permeability transition pore (MPTP)-mediated necrosis. Several distinctive executive molecules, particularly residing on the mitochondrial inner and outer membrane, amalgamating to form the MPTP have been defined. The c-subunit of the F1F0ATP synthase on the inner membrane and Bax/Bak on the outer membrane are considered to be the long sought components that form the MPTP. Opening of the MPTP results in loss of mitochondrial inner membrane potential, disruption of ATP production, increased ROS production, organelle swelling, mitochondrial dysfunction and consequent necrosis. Cyclophilin D, along with adenine nucleotide translocator and the phosphate carrier are considered to be important regulators involved in the opening of MPTP. Increased production of ROS can further trigger other necrotic pathways mediated through molecules such as PARP1, leading to irreversible cell damage. This review examines the roles of PARP1 and cyclophilin D in necrotic cell death. The hierarchical role of p53 in regulation and integration of key components of signaling pathway to elicit MPTP-mediated necrosis and ferroptosis is explored. In the context of recent insights, the indistinct role of necroptosis signaling in tubular necrosis after ischemic kidney injury is scrutinized. We conclude by discussing the participation of p53, PARP1 and cyclophilin D and their overlapping pathways to elicit MPTP-mediated necrosis and ferroptosis in acute kidney injury. PMID:27048819

  9. Photoreceptor phagosome processing defects and disturbed autophagy in retinal pigment epithelium of Cln3Δex1-6 mice modelling juvenile neuronal ceroid lipofuscinosis (Batten disease).

    PubMed

    Wavre-Shapton, Silène T; Calvi, Alessandra A; Turmaine, Mark; Seabra, Miguel C; Cutler, Daniel F; Futter, Clare E; Mitchison, Hannah M

    2015-12-15

    Retinal degeneration and visual impairment are the first signs of juvenile neuronal ceroid lipofuscinosis caused by CLN3 mutations, followed by inevitable progression to blindness. We investigated retinal degeneration in Cln3(Δex1-6) null mice, revealing classic 'fingerprint' lysosomal storage in the retinal pigment epithelium (RPE), replicating the human disease. The lysosomes contain mitochondrial F0-ATP synthase subunit c along with undigested membranes, indicating a reduced degradative capacity. Mature autophagosomes and basal phagolysosomes, the terminal degradative compartments of autophagy and phagocytosis, are also increased in Cln3(Δex1) (-6) RPE, reflecting disruption to these key pathways that underpin the daily phagocytic turnover of photoreceptor outer segments (POS) required for maintenance of vision. The accumulated autophagosomes have post-lysosome fusion morphology, with undigested internal contents visible, while accumulated phagosomes are frequently docked to cathepsin D-positive lysosomes, without mixing of phagosomal and lysosomal contents. This suggests lysosome-processing defects affect both autophagy and phagocytosis, supported by evidence that phagosomes induced in Cln3(Δex1) (-) (6)-derived mouse embryonic fibroblasts have visibly disorganized membranes, unprocessed internal vesicles and membrane contents, in addition to reduced LAMP1 membrane recruitment. We propose that defective lysosomes in Cln3(Δex1) (-) (6) RPE have a reduced degradative capacity that impairs the final steps of the intimately connected autophagic and phagocytic pathways that are responsible for degradation of POS. A build-up of degradative organellar by-products and decreased recycling of cellular materials is likely to disrupt processes vital to maintenance of vision by the RPE. PMID:26450516

  10. The participation of metals in the mechanism of the F(1)-ATPase.

    PubMed

    Frasch, W D

    2000-05-31

    The Mg(2+) cofactor of the F(1)F(0) ATP synthase is required for the asymmetry of the catalytic sites that leads to the differences in affinity for nucleotides. Vanadyl (V(IV)=O)(2+) is a functional surrogate for Mg(2+) in the F(1)-ATPase. The (51)V-hyperfine parameters derived from EPR spectra of VO(2+) bound to specific sites on the enzyme provide a direct probe of the metal ligands at each site. Site-directed mutations of residues that serve as metal ligands were found to cause measurable changes in the (51)V-hyperfine parameters of the bound VO(2+), thereby providing a means by which metal ligands were identified in the functional enzyme in several conformations. At the low-affinity catalytic site comparable to beta(E) in mitochondrial F(1), activation of the chloroplast F(1)-ATPase activity induces a conformational change that inserts the P-loop threonine and catch-loop tyrosine hydroxyl groups into the metal coordination sphere thereby displacing an amino group and the Walker homology B aspartate. Kinetic evidence suggests that coordination of this tyrosine by the metal when the empty site binds substrate may provide an escapement mechanism that allows the gamma subunit to rotate and the conformation of the catalytic sites to change, thereby allowing rotation only when the catalytic sites are filled. In the high-affinity conformation analogous to the beta(DP) site of mitochondrial F(1), the catch-loop tyrosine has been displaced by carboxyl groups from the Walker homology B aspartate and from betaE197 in Chlamydomonas CF(1). Coordination of the metal by these carboxyl groups contributes significantly to the ability of the enzyme to bind the nucleotide with high affinity. PMID:10838047

  11. Photoreceptor phagosome processing defects and disturbed autophagy in retinal pigment epithelium of Cln3Δex1-6 mice modelling juvenile neuronal ceroid lipofuscinosis (Batten disease)

    PubMed Central

    Wavre-Shapton, Silène T.; Calvi, Alessandra A.; Turmaine, Mark; Seabra, Miguel C.; Cutler, Daniel F.; Futter, Clare E.; Mitchison, Hannah M.

    2015-01-01

    Retinal degeneration and visual impairment are the first signs of juvenile neuronal ceroid lipofuscinosis caused by CLN3 mutations, followed by inevitable progression to blindness. We investigated retinal degeneration in Cln3Δex1-6 null mice, revealing classic ‘fingerprint’ lysosomal storage in the retinal pigment epithelium (RPE), replicating the human disease. The lysosomes contain mitochondrial F0-ATP synthase subunit c along with undigested membranes, indicating a reduced degradative capacity. Mature autophagosomes and basal phagolysosomes, the terminal degradative compartments of autophagy and phagocytosis, are also increased in Cln3Δex1-6 RPE, reflecting disruption to these key pathways that underpin the daily phagocytic turnover of photoreceptor outer segments (POS) required for maintenance of vision. The accumulated autophagosomes have post-lysosome fusion morphology, with undigested internal contents visible, while accumulated phagosomes are frequently docked to cathepsin D-positive lysosomes, without mixing of phagosomal and lysosomal contents. This suggests lysosome-processing defects affect both autophagy and phagocytosis, supported by evidence that phagosomes induced in Cln3Δex1-6-derived mouse embryonic fibroblasts have visibly disorganized membranes, unprocessed internal vesicles and membrane contents, in addition to reduced LAMP1 membrane recruitment. We propose that defective lysosomes in Cln3Δex1-6 RPE have a reduced degradative capacity that impairs the final steps of the intimately connected autophagic and phagocytic pathways that are responsible for degradation of POS. A build-up of degradative organellar by-products and decreased recycling of cellular materials is likely to disrupt processes vital to maintenance of vision by the RPE. PMID:26450516

  12. Investigation of Geotrichum candidum gene expression during the ripening of Reblochon-type cheese by reverse transcription-quantitative PCR.

    PubMed

    Castellote, Jessie; Fraud, Sébastien; Irlinger, Françoise; Swennen, Dominique; Fer, Frédéric; Bonnarme, Pascal; Monnet, Christophe

    2015-02-01

    Cheese ripening involves the activity of various bacteria, yeasts or molds, which contribute to the development of the typical color, flavor and texture of the final product. In situ measurements of gene expression are increasingly being used to improve our understanding of the microbial flora activity in cheeses. The objective of the present study was to investigate the physiology and metabolic activity of Geotrichum candidum during the ripening of Reblochon-type cheeses by quantifying mRNA transcripts at various ripening times. The expression of 80 genes involved in various functions could be quantified with a correct level of biological repeatability using a set of three stable reference genes. As ripening progresses, a decrease in expression was observed for genes involved in cell wall organization, translation, vesicular mediated transport, and in cytoskeleton constituents and ribosomal protein genes. There was also a decrease in the expression of mitochondrial F1F0 ATP synthase and plasma membrane H(+) ATPase genes. Some genes involved in the catabolism of lactate, acetate and ethanol were expressed to a greater extent at the beginning of ripening. During the second part of ripening, there was an increased expression of genes involved in the transport and catabolism of amino acids, which could be attributed to a change in the energy source. There was also an increase in the expression of genes involved in autophagy and of genes possibly involved in lifespan determination. Quantification of mRNA transcripts may also be used to produce bioindicators relevant for cheesemaking, for example when considering genes encoding enzymes involved in the catabolism of amino acids. PMID:25461609

  13. Electrostatic interactions in catalytic centers of F1-ATPase

    NASA Astrophysics Data System (ADS)

    Pogrebnaya, Alexandra F.; Romanovsky, Yury M.; Tikhonov, Alexander N.

    2003-10-01

    F1-ATPase is one of the most important enzymes of membrane bioenergetics. F1-ATPase is the constituent complex that provides the ATP formation from ADP and inorganic phosphate (Pi) at the expense of energy of electrochemical gradient of hydrogen ions generated across the energy transducing mitochondrial, chloroplast or bacterial membrane. F1-ATPase is a reversible molecular machine that can work as a proton pump due to energy released in the course of ATP hydrolysis (ATPase reaction). The unusual feature of this enzyme is that it operates as a rotary molecular motor. Recently, using the fluorescence microscopy method for the real time visualization of molecular mobility of individual molecules, it was demonstrated directly that the ATP hydrolysis by F1-ATPase is accompanied by unidirectional rotations of mobile subunits (rotor) of F1F0-ATP synthase. In this work, we calculated the contribution of electrostatic interactions between charged groups of a substrate (MgATP), products molecules (MgADP and Pi), and charged amino acid residuals of ATPase molecule to the energy changes associated with the substrate binding and their chemical transformations in the catalytic centers located at the interface of α and β subunits of the enzyme (oligomer complex α3β3γ of bovine mitochondria ATPase). A catalytic cycle of ATP hydrolysis considered in our work includes conformational changes of α and β subunits caused by unidirectional rotations of an eccentric γ subunit. The knowledge of energy characteristics and force field in catalytic center of an enzyme in different conformational states may be important for further simulation dynamic properties of ATP synthase complex.

  14. A Novel High-Throughput Assay for Islet Respiration Reveals Uncoupling of Rodent and Human Islets

    PubMed Central

    Wikstrom, Jakob D.; Sereda, Samuel B.; Stiles, Linsey; Elorza, Alvaro; Allister, Emma M.; Neilson, Andy; Ferrick, David A.; Wheeler, Michael B.; Shirihai, Orian S.

    2012-01-01

    Background The pancreatic beta cell is unique in its response to nutrient by increased fuel oxidation. Recent studies have demonstrated that oxygen consumption rate (OCR) may be a valuable predictor of islet quality and long term nutrient responsiveness. To date, high-throughput and user-friendly assays for islet respiration are lacking. The aim of this study was to develop such an assay and to examine bioenergetic efficiency of rodent and human islets. Methodology/Principal Findings The XF24 respirometer platform was adapted to islets by the development of a 24-well plate specifically designed to confine islets. The islet plate generated data with low inter-well variability and enabled stable measurement of oxygen consumption for hours. The F1F0 ATP synthase blocker oligomycin was used to assess uncoupling while rotenone together with myxothiazol/antimycin was used to measure the level of non-mitochondrial respiration. The use of oligomycin in islets was validated by reversing its effect in the presence of the uncoupler FCCP. Respiratory leak averaged to 59% and 49% of basal OCR in islets from C57Bl6/J and FVB/N mice, respectively. In comparison, respiratory leak of INS-1 cells and C2C12 myotubes was measured to 38% and 23% respectively. Islets from a cohort of human donors showed a respiratory leak of 38%, significantly lower than mouse islets. Conclusions/Significance The assay for islet respiration presented here provides a novel tool that can be used to study islet mitochondrial function in a relatively high-throughput manner. The data obtained in this study shows that rodent islets are less bioenergetically efficient than human islets as well as INS1 cells. PMID:22606219

  15. Altered Lipid Synthesis by Lack of Yeast Pah1 Phosphatidate Phosphatase Reduces Chronological Life Span.

    PubMed

    Park, Yeonhee; Han, Gil-Soo; Mileykovskaya, Eugenia; Garrett, Teresa A; Carman, George M

    2015-10-16

    In Saccharomyces cerevisiae, Pah1 phosphatidate phosphatase, which catalyzes the dephosphorylation of phosphatidate to yield diacylglycerol, plays a crucial role in the synthesis of the storage lipid triacylglycerol. This evolutionarily conserved enzyme also plays a negative regulatory role in controlling de novo membrane phospholipid synthesis through its consumption of phosphatidate. We found that the pah1Δ mutant was defective in the utilization of non-fermentable carbon sources but not in oxidative phosphorylation; the mutant did not exhibit major changes in oxygen consumption rate, mitochondrial membrane potential, F1F0-ATP synthase activity, or gross mitochondrial morphology. The pah1Δ mutant contained an almost normal complement of major mitochondrial phospholipids with some alterations in molecular species. Although oxidative phosphorylation was not compromised in the pah1Δ mutant, the cellular levels of ATP in quiescent cells were reduced by 2-fold, inversely correlating with a 4-fold increase in membrane phospholipids. In addition, the quiescent pah1Δ mutant cells had 3-fold higher levels of mitochondrial superoxide and cellular lipid hydroperoxides, had reduced activities of superoxide dismutase 2 and catalase, and were hypersensitive to hydrogen peroxide. Consequently, the pah1Δ mutant had a shortened chronological life span. In addition, the loss of Tsa1 thioredoxin peroxidase caused a synthetic growth defect with the pah1Δ mutation. The shortened chronological life span of the pah1Δ mutant along with its growth defect on non-fermentable carbon sources and hypersensitivity to hydrogen peroxide was suppressed by the loss of Dgk1 diacylglycerol kinase, indicating that the underpinning of pah1Δ mutant defects was the excess synthesis of membrane phospholipids. PMID:26338708

  16. Mechanism of anaerobic degradation of triethanolamine by a homoacetogenic bacterium

    SciTech Connect

    Speranza, Giovanna . E-mail: giovanna.speranza@unimi.it; Morelli, Carlo F.; Cairoli, Paola; Mueller, Britta; Schink, Bernhard

    2006-10-20

    Triethanolamine (TEA) is converted into acetate and ammonia by a strictly anaerobic, gram-positive Acetobacterium strain LuTria3. Fermentation experiments with resting cell suspensions and specifically deuterated substrates indicate that in the acetate molecule the carboxylate and the methyl groups correspond to the alcoholic function and to its adjacent methylene group, respectively, of the 2-hydroxyethyl unit of TEA. A 1,2 shift of a hydrogen (deuterium) atom from -CH{sub 2} -O- to =N-CH{sub 2} - without exchange with the medium was observed. This fact gives evidence that a radical mechanism occurs involving the enzyme and/or coenzyme molecule as a hydrogen carrier. Such a biodegradation appears analogous to the conversion of 2-phenoxyethanol into acetate mediated by another strain of the anaerobic homoacetogenic bacterium Acetobacterium.

  17. Transformation of tetrachloroethylene to trichloroethylene by homoacetogenic bacteria.

    PubMed

    Terzenbach, D P; Blaut, M

    1994-10-15

    Eight homoacetogenic strains of the genera Acetobacterium, Clostridium and Sporomusa were tested for their ability to dechlorinate tetrachloroethylene (perchloroethene, PCE). Of the organisms tested only Sporomusa ovata was able to reductively dechlorinate PCE with methanol as an electron donor. Resting cells of S. ovata reductively dechlorinated PCE at a rate of 9.8 nmol h-1 (mg protein)-1 to trichloroethylene (TCE) as the sole product. The dechlorination activity depended on concomitant acetogenesis from methanol and CO2. Cell-free extracts of S. ovata, Clostridium formicoaceticum, Acetobacterium woodii, and the methanogenic bacterium Methanolobus tindarius transformed PCE to TCE with Ti(III) or carbon monoxide as electron donors. Corrinoids were shown in S. ovata to be involved in the dechlorination reaction of PCE to TCE as evident from the reversible inhibition with propyl iodide. Rates of dechlorination followed a pseudo-first-order kinetic. PMID:7988892

  18. [Catalase and superoxide dismutase in the cells of strictly anaerobic microorganisms].

    PubMed

    Briukhanov, A L; Thauer, R K; Netrusov, A I

    2002-01-01

    Strictly anaerobic microorganisms relating to various physiological groups were screened for catalase and superoxide dismutase (SOD) activity. All of the investigated anaerobes possessed the SOD activity, necessary for protection against toxic products of oxygen reduction. High specific activities of SOD were found in Acetobacterium woodii and Acetobacterium wieringae. Most of the investigated clostridia and acetogens were catalase-negative. A significant activity of catalase was found in Thermohydrogenium kirishiense, in representatives of the genus Desulfotomaculum, and in several methanogens. Methanobrevibacter arboriphilus had an exceptionally high catalase activity after growth in medium supplemented with hemin. Hemin also produced a strong positive effect on the catalase activity in many other anaerobic microorganisms. In methanogens, the activities of the enzymes of antioxidant defense varied in wide ranges depending on the stage of growth and the energy source. PMID:12138753

  19. Transformation of gram positive bacteria by sonoporation

    DOEpatents

    Yang, Yunfeng; Li, Yongchao

    2014-03-11

    The present invention provides a sonoporation-based method that can be universally applied for delivery of compounds into Gram positive bacteria. Gram positive bacteria which can be transformed by sonoporation include, for example, Bacillus, Streptococcus, Acetobacterium, and Clostridium. Compounds which can be delivered into Gram positive bacteria via sonoporation include nucleic acids (DNA or RNA), proteins, lipids, carbohydrates, viruses, small organic and inorganic molecules, and nano-particles.

  20. Is the incidence of heart attack still decreasing in Australia? Developing reliable methods for monitoring trends in myocardial infarction and coronary heart disease (AUS-MOCHA): a study protocol

    PubMed Central

    Nedkoff, Lee; Knuiman, Matthew; Hobbs, Michael S T; Hung, Joseph; Mathur, Sushma; Beilby, John; Reynolds, Anna; Briffa, Tom G; Lopez, Derrick

    2016-01-01

    Introduction Accurate monitoring of acute coronary heart disease (CHD) is essential for understanding the effects of primary and secondary prevention and for planning of healthcare services. The ability to reliably monitor acute CHD has been affected by new diagnostic tests for myocardial infarction (MI) and changing clinical classifications and management of CHD. Our study will develop new and reliable methods for monitoring population trends in incidence, outcomes and health service usage for acute CHD and chest pain. Methods and analysis The study cohort of all CHD will be identified from the Western Australian Data Linkage System using state-wide data sets for emergency department presentation, hospitalisations and mortality data for 2002–2014. This core linked data set will be supplemented with data from hospital medical record reviews, pathology data and hospital pharmacy dispensing databases. The consistency over time of the coding of the different subgroups of CHD/chest pain (ST-elevation MI, non-ST elevation MI, unstable angina, stable angina, other CHD, non-CHD chest pain) in linked data will be assessed using these data sources, and an algorithm developed detailing groups in which temporal trends can be reliably measured. This algorithm will be used for measurement of trends in incidence and outcomes of acute CHD, and to develop further methods for monitoring acute CHD using unlinked and linked data with varying availability of hospitalisation history. Ethics and dissemination Ethics approval has been obtained from the Human Research Ethics Committees of the WA Department of Health (#2016/23) and The University of Western Australia (RA/4/1/7230). Findings will be disseminated via publication in peer-reviewed journals, and presentation at national and international conferences. There will also be a strong platform for dissemination of new monitoring methods via collaboration with the Australian Institute of Health and Welfare which will assist with promotion of these methods at state and national levels. PMID:27558904

  1. Learning from History: The Nazi Era and the Holocaust in German Education = Lernen aus geschichte: Projekte zu Nationalsozialismus und Holocaust in schule und jugendar beit. [With CD-ROM].

    ERIC Educational Resources Information Center

    Brinkmann, Annette, Ed.; Ehmann, Annegret, Ed.; Milton, Sybil, Ed.; Rathenow, Hanns-Fred, Ed.; Wyrwoll, Regina, Ed.

    This project is the result of extensive research about the practical applications of "National Socialism and the Holocaust" in historical and political education in and outside schools and in educational work with young people. The multifaceted documentation, on CD-ROM, booklet and a Web site is aimed at a broad international and educational…

  2. Praxisorientierter Ansatz zur kartographischen Darstellung von Karst-Grundwasserressourcen. Erfahrungen aus dem SWISSKARST-Projekt A practical approach for mapping karst groundwater resources

    NASA Astrophysics Data System (ADS)

    Malard, Arnauld; Jeannin, Pierre-Yves; Sinreich, Michael; Weber, Eric; Vouillamoz, Jonathan; Eichenberger, Urs

    2014-12-01

    In spite of their abundant water resources, in Switzerland as well as in other countries, the location and extent of karst aquifers have not yet been systematically studied and documented - mainly due to the lack of systematic and dedicated approaches for their characterization. In the framework of a project aiming at documenting the karst aquifers in Switzerland (SWISSKARST Project) the pragmatic KARSYS approach has been developed to systematically assess the main characteristics of karst aquifers and karst systems. One part of this project deals with the development of a practical method for mapping 2D hydrogeological karst systems, which is designed to address both scientific and applied issues. A series of maps based on the approach is proposed to describe the main characteristics of karst groundwater systems resulting in a synthesized map which suitably combines all relevant information.

  3. "Weil Man da Uber Seine Probleme Reden Kann . . ." Partielle Geschlechtertrennung aus der Sicht der Schulerinnen und Schuler ("Because There, You can Talk about Your Problems . . ." Partial Separation by Gender from the Perspective of Male and Female Students).

    ERIC Educational Resources Information Center

    Biskup, Claudia; Pfister, Gertrud; Robke, Cathrin

    1998-01-01

    Examines the results of interviews with elementary school children that gauged the attitudes towards and reasons for a partial separation by gender. Proposes an occassional separation of girls and boys for special pedogogical intervention. Discusses the findings. (CMK)

  4. Schwachstelle Sprachpraxis. Ueberlegungen und Vorschlaege zur sprachpraktischen Aus- und Weiterbildung des Englischlehrers (Weak Spot: Language Practice. Considerations and Suggestions concerning Language Practice in the Education and Continued Training of English Teachers).

    ERIC Educational Resources Information Center

    Hoegel, Rolf

    1979-01-01

    Recommends foreign-language camps as a remedy for lack of practice in speaking. Relates experiences with a two-day camp at a youth hostel in North Germany, for 25 to 30 students from a teachers' college. Advantages of such camps are described and details of the program are given. (IFS/WGA)

  5. Dreissig Jahre Volksrepublik Polen. Aus den Thesen des Zentralkomitees der Polnischen Vereinigten Arbeiterpartei (Thirty years of the People's Republic of Poland. From the Theses of the Central Committee of the Polish United Workers' Party)

    ERIC Educational Resources Information Center

    Fremdsprachenunterricht, 1974

    1974-01-01

    Offers an overview of the development of the teaching of Russian in the People's Republic of Poland since its introduction in 1945 and the support of the periodical "Jezyk Rosyjski" (Russian Language) in the attainment of the goals set by the Ministry of Popular Education of the People's Republic of Poland. (Text is in German.) (IFS/WGA)

  6. "Onkle Karl" aus Milwaukee: Deutsch-amerikanische Einwandererkultur im Spiegel der Jugendliteratur vor hundert Jahren (Uncle Carl from Milwaukee: German-American Newcomer Culture Reflected in Children's Literature a Hundred Years Ago).

    ERIC Educational Resources Information Center

    Weiss, Gerhard

    1998-01-01

    Examines a late nineteenth-century Milwaukee (Wisconsin) publication for children and young people as a reflection of German-American middle-class culture of the time, showing how the spirit of the 1848 revolution and the experience of the American Civil War shaped German-American intellectuals and how the ideals of freedom and equality dominated…

  7. Intensity Estimation of Spontaneous Facial Action Units Based on Their Sparsity Properties.

    PubMed

    Mohammadi, Mohammad Reza; Fatemizadeh, Emad; Mahoor, Mohammad H

    2016-03-01

    Automatic measurement of spontaneous facial action units (AUs) defined by the facial action coding system (FACS) is a challenging problem. The recent FACS user manual defines 33 AUs to describe different facial activities and expressions. In spontaneous facial expressions, a subset of AUs are often occurred or activated at a time. Given this fact that AUs occurred sparsely over time, we propose a novel method to detect the absence and presence of AUs and estimate their intensity levels via sparse representation (SR). We use the robust principal component analysis to decompose expression from facial identity and then estimate the intensity of multiple AUs jointly using a regression model formulated based on dictionary learning and SR. Our experiments on Denver intensity of spontaneous facial action and UNBC-McMaster shoulder pain expression archive databases show that our method is a promising approach for measurement of spontaneous facial AUs. PMID:25861093

  8. Metabolic labeling with stable isotope nitrogen (15N) to follow amino acid and protein turnover of three plastid proteins in Chlamydomonas reinhardtii

    PubMed Central

    2014-01-01

    Background The length of time that a protein remains available to perform its function is significantly influenced by its turnover rate. Knowing the turnover rate of proteins involved in different processes is important to determining how long a function might progress even when the stimulus has been removed and no further synthesis of the particular proteins occurs. In this article, we describe the use of 15N-metabolic labeling coupled to GC-MS to follow the turnover of free amino acids and LC-MS/MS to identify and LC-MS to follow the turnover of specific proteins in Chlamydomonas reinhardtii. Results To achieve the metabolic labeling, the growth medium was formulated with standard Tris acetate phosphate medium (TAP) in which14NH4Cl was replaced with 15NH415NO3 and (14NH4)6Mo7O24.4H2O was replaced with Na2MoO4.2H2O. This medium designated 15N-TAP allowed CC-125 algal cells to grow normally. Mass isotopic distribution revealed successful 15N incorporation into 13 amino acids with approximately 98% labeling efficiency. Tryptic digestion of the 55 kDa SDS-PAGE bands from 14N- and 15N-labeled crude algal protein extracts followed by LC-MS/MS resulted in the identification of 27 proteins. Of these, five displayed peptide sequence confidence levels greater than 95% and protein sequence coverage greater than 25%. These proteins were the RuBisCo large subunit, ATP synthase CF1 alpha and beta subunits, the mitochondrial protein (F1F0 ATP synthase) and the cytosolic protein (S-adenosyl homocysteine hydroxylase). These proteins were present in both labeled and unlabeled samples. Once the newly synthesized 15N-labeled free amino acids and proteins obtained maximum incorporation of the 15N-label, turnover rates were determined after transfer of cells into 14N-TAP medium. The t½ values were determined for the three plastid proteins (RuBisCo, ATP synthase CF1 alpha and beta) by following the reduction of the 15N-fractional abundance over time. Conclusion We describe a more

  9. Comparative reaction engineering analysis of different acetogenic bacteria for gas fermentation.

    PubMed

    Groher, Anna; Weuster-Botz, Dirk

    2016-06-20

    The production of chemicals by syngas fermentation is a promising alternative to heterotrophic fermentation processes. The autotrophic process performances of the so far not well studied acetogens Acetobacterium fimetarium, Acetobacterium wieringae, Blautia hydrogenotrophica, Clostridium magnum, Eubacterium aggregans, Sporomusa acidovorans, Sporomusa ovata and Terrisporobacter mayombei were characterized. Acetobacterium woodii was used as reference strain. Standardized batch experiments with continuous supply of the gaseous substrates CO2 and H2 were performed in fully controlled stirred-tank bioreactors. A. wieringae and S. ovata showed by far the highest growth rates and maximum biomass concentrations among the acetogens under study. Aside from the reference strain A. woodii, highest volumetric (17.96gL(-1)d(-1)) as well as cell specific acetate formation rates (21.03gg(-1)d(-1)) were observed with S. ovata resulting in a final acetate concentration of 32.2gL(-1). Accumulation of formate with up to 4.8gL(-1) was observed with all acetogens. Ethanol was produced autotrophically with up to 0.42gL(-1) by four of the acetogenic bacteria under study (A. wieringae, C. magnum, S. acidovorans and S. ovata) and also by A. woodii. Butyrate was formed with up to 0.14gL(-1) by three of the acetogenic bacteria under study (C. magnum, B. hydrogenotrophica and E. aggregans). Due to its superior process performances S. ovata may be a promising host for redirecting carbon fluxes by applying metabolic engineering and tools of synthetic biology to produce non-natural chemicals from syngas. PMID:27107467

  10. Microbiology and physiology of anaerobic fermentations of cellulose. Progress report, September 1982-March 1983

    SciTech Connect

    Peck, H.D. Jr.; Ljungdahl, L.G.

    1983-01-01

    Research progress for the period September 1982-March 1983 is reported. The cellulose enzyme system of the anaerobic thermophile Clostridium thermocellum is being studied. Mutants have been obtained from thermoanaerobacter ethanolicus which produce higher amounts of ethanol than does the wild type. Clostridium thermoautotrophicum has been studied with respect to the pathway of acetate synthesis from CO/sub 2/. Progress has been achieved on properties of the NADP-dependent formate dehydrogenase and the CO dehydrogenase of Clostridium thermoaceticum. The CO dehydrogenase of Acetobacterium woodii has been isolated. Research has continued on the bioenergetics of dissimilatory sulfate reduction in sulfate reducing and methanogenic bacteria.

  11. Tolerance and metabolic response of acetogenic bacteria toward oxygen.

    PubMed

    Karnholz, Arno; Küsel, Kirsten; Gössner, Anita; Schramm, Andreas; Drake, Harold L

    2002-02-01

    The acetogens Sporomusa silvacetica, Moorella thermoacetica, Clostridium magnum, Acetobacterium woodii, and Thermoanaerobacter kivui (i) grew in both semisolid and liquid cultivation media containing O(2) and (ii) consumed small amounts of O(2). Low concentrations of O(2) caused a lag phase in growth but did not alter the ability of these acetogens to synthesize acetate via the acetyl coenzyme A pathway. Cell extracts of S. silvacetica, M. thermoacetica, and C. magnum contained peroxidase and NADH oxidase activities; catalase and superoxide dismutase activities were not detected. PMID:11823254

  12. The accuracy of preoperative axillary nodal staging in primary breast cancer by ultrasound is modified by nodal metastatic load and tumor biology.

    PubMed

    Dihge, Looket; Grabau, Dorthe A; Rasmussen, Rogvi W; Bendahl, Pär-Ola; Rydén, Lisa

    2016-08-01

    Background The outcome of axillary ultrasound (AUS) with fine-needle aspiration biopsy (FNAB) in the diagnostic work-up of primary breast cancer has an impact on therapy decisions. We hypothesize that the accuracy of AUS is modified by nodal metastatic burden and clinico-pathological characteristics. Material and methods The performance of AUS and AUS-guided FNAB for predicting nodal metastases was assessed in a prospective breast cancer cohort subjected for surgery during 2009-2012. Predictors of accuracy were included in multivariate analysis. Results AUS had a sensitivity of 23% and a specificity of 95%, while AUS-guided FNAB obtained 73% and 100%, respectively. AUS-FNAB exclusively detected macro-metastases (median four metastases) and identified patients with more extensive nodal metastatic burden in comparison with sentinel node biopsy. The accuracy of AUS was affected by metastatic size (OR 1.11), obesity (OR 2.46), histological grade (OR 4.43), and HER2-status (OR 3.66); metastatic size and histological grade were significant in the multivariate analysis. Conclusions The clinical utility of AUS in low-risk breast cancer deserves further evaluation as the accuracy decreased with a low nodal metastatic burden. The diagnostic performance is modified by tumor and clinical characteristics. Patients with nodal disease detected by AUS-FNAB represent a group for whom neoadjuvant therapy should be considered. PMID:27050668

  13. Magnitude of phonetic distinction predicts success at early word learning in native and non-native accents

    PubMed Central

    Escudero, Paola; Best, Catherine T.; Kitamura, Christine; Mulak, Karen E.

    2014-01-01

    Although infants perceptually attune to native vowels and consonants well before 12 months, at 13–15 months, they have difficulty learning to associate novel words that differ by their initial consonant (e.g., BIN and DIN) to their visual referents. However, this difficulty may not apply to all minimal pair novel words. While Canadian English (CE) 15-month-olds failed to respond to a switch from the newly learned word DEET to the novel non-word DOOT, they did notice a switch from DEET to DIT (Curtin et al., 2009). Those authors argued that early word learners capitalize on large phonetic differences, seen in CE DEET–DIT, but not on smaller phonetic differences, as in CE DEET–DOOT. To assess this hypothesis, we tested Australian English (AusE) 15-month-olds, as AusE has a smaller magnitude of phonetic difference in both novel word pairs. Two groups of infants were trained on the novel word DEET and tested on the vowel switches in DIT and DOOT, produced by an AusE female speaker or the same CE female speaker as in Curtin et al. (2009). If the size of the phonetic distinction plays a more central role than native accent experience in early word learning, AusE children should more easily recognize both of the unfamiliar but larger CE vowel switches than the more familiar but smaller AusE ones. The results support our phonetic-magnitude hypothesis: AusE children taught and tested with the CE-accented novel words looked longer to both of the switch test trials (DIT, DOOT) than same test trials (DEET), while those who heard the AusE-accented tokens did not notice either switch. Implications of our findings for models of early word learning are discussed. PMID:25324793

  14. Culturable prokaryotic diversity of deep, gas hydrate sediments: first use of a continuous high-pressure, anaerobic, enrichment and isolation system for subseafloor sediments (DeepIsoBUG)

    PubMed Central

    Parkes, R John; Sellek, Gerard; Webster, Gordon; Martin, Derek; Anders, Erik; Weightman, Andrew J; Sass, Henrik

    2009-01-01

    Deep subseafloor sediments may contain depressurization-sensitive, anaerobic, piezophilic prokaryotes. To test this we developed the DeepIsoBUG system, which when coupled with the HYACINTH pressure-retaining drilling and core storage system and the PRESS core cutting and processing system, enables deep sediments to be handled without depressurization (up to 25 MPa) and anaerobic prokaryotic enrichments and isolation to be conducted up to 100 MPa. Here, we describe the system and its first use with subsurface gas hydrate sediments from the Indian Continental Shelf, Cascadia Margin and Gulf of Mexico. Generally, highest cell concentrations in enrichments occurred close to in situ pressures (14 MPa) in a variety of media, although growth continued up to at least 80 MPa. Predominant sequences in enrichments were Carnobacterium, Clostridium, Marinilactibacillus and Pseudomonas, plus Acetobacterium and Bacteroidetes in Indian samples, largely independent of media and pressures. Related 16S rRNA gene sequences for all of these Bacteria have been detected in deep, subsurface environments, although isolated strains were piezotolerant, being able to grow at atmospheric pressure. Only the Clostridium and Acetobacterium were obligate anaerobes. No Archaea were enriched. It may be that these sediment samples were not deep enough (total depth 1126–1527 m) to obtain obligate piezophiles. PMID:19694787

  15. Culturable prokaryotic diversity of deep, gas hydrate sediments: first use of a continuous high-pressure, anaerobic, enrichment and isolation system for subseafloor sediments (DeepIsoBUG).

    PubMed

    Parkes, R John; Sellek, Gerard; Webster, Gordon; Martin, Derek; Anders, Erik; Weightman, Andrew J; Sass, Henrik

    2009-12-01

    Deep subseafloor sediments may contain depressurization-sensitive, anaerobic, piezophilic prokaryotes. To test this we developed the DeepIsoBUG system, which when coupled with the HYACINTH pressure-retaining drilling and core storage system and the PRESS core cutting and processing system, enables deep sediments to be handled without depressurization (up to 25 MPa) and anaerobic prokaryotic enrichments and isolation to be conducted up to 100 MPa. Here, we describe the system and its first use with subsurface gas hydrate sediments from the Indian Continental Shelf, Cascadia Margin and Gulf of Mexico. Generally, highest cell concentrations in enrichments occurred close to in situ pressures (14 MPa) in a variety of media, although growth continued up to at least 80 MPa. Predominant sequences in enrichments were Carnobacterium, Clostridium, Marinilactibacillus and Pseudomonas, plus Acetobacterium and Bacteroidetes in Indian samples, largely independent of media and pressures. Related 16S rRNA gene sequences for all of these Bacteria have been detected in deep, subsurface environments, although isolated strains were piezotolerant, being able to grow at atmospheric pressure. Only the Clostridium and Acetobacterium were obligate anaerobes. No Archaea were enriched. It may be that these sediment samples were not deep enough (total depth 1126-1527 m) to obtain obligate piezophiles. PMID:19694787

  16. Schule in der Transformation--Transformation der Schule? Was man aus Gesprachen mit ehemaligen Schulern uber die Schule "zwischen zwei Diktaturen" erfahren kann (Schools in Transitions--Transformation of the School? What Can Be Learnt from Former Students Who Experienced Schooling under Two Dictatorial Regimes).

    ERIC Educational Resources Information Center

    Kluchert, Gerhard; Leschinsky, Achim

    1998-01-01

    Addresses interviews that focused on former students' educations under two dictatorial regimes. All the interviewees took their school-leaving examinations between 1951 and 1954. Explains that the interviews are evaluated according to the preconditions, limits, and mechanisms of the school's influence on children and adolescents. (CMK)

  17. Mentalitat und Intergenerationalitat als Rahmenbedingungen "Lebenslangen Lernens". Konzeptionelle Konsequenzen aus Ergebnissen einer Biografieanalytischen Mehrgenerationenstudie in Ostdeutschland (Mentality and Intergenerationality as Framework Conditions of "Life-Long Learning": Conceptual Consequences To Be Drawn from Results of a Biography-Analytical Multi-Generational Study Carried out in East Germany).

    ERIC Educational Resources Information Center

    Alheit, Peter

    2003-01-01

    Discusses a comprehensive qualitative multigenerational study carried out in East Germany. Shows that social orientations and attitudes remained practically unchanged between the generation of grandparents and grandchildren. Argues that educational processes throughout a life-span can only be understood if mental deep structures and…

  18. Allgemeine Sprachfaehigkeit und Fremdsprachenerwerb. Zur Struktur von Leistungsdimensionen und linguistischer Kompetenz des Fremdsprachenlerners (General Language Ability and Foreign Language Acquisition. On the Structure of Performance Dimensions and the Linguistic Competence of the Foreign Language Learner). Diskussions beitraege aus dem Institute fuer Bildungsforschung, No. 1.

    ERIC Educational Resources Information Center

    Sang, Fritz; Vollmer, Helmut J.

    This study investigates the theoretical plausibility and empirical validity of the assumption that all performance in a foreign language can be traced back to a single factor, the general language ability factor. The theoretical background of this hypothesis is reviewed in detail. The concept of a unitary linguistic competence, interpreted as an…

  19. Pumpspeicherbecken im Karstgrundwasserleiter des Weißen Jura der Schwäbischen Alb. Erste Ergebnisse aus der geologischen und hydrogeologischen Erkundung für die Planfeststellung Pumped-storage hydroelectric power plant in the Jurassic karst aquifer of the swabian alb, Germany

    NASA Astrophysics Data System (ADS)

    Neukum, Christoph; Köhler, Hans Joachim; Fernandez-Steeger, Tomas; Hennings, Sibylle; Azzam, Rafig

    2014-06-01

    Extensive geological and hydrogeological investigations have been undertaken for the planned pumped-storage hydroelectric power plant in "Blautal" (Swabian Alb, Germany) in order to characterise the Jurassic karst aquifer in which the lower reservoir will be constructed. The preferred option for the plant setup is to integrate the lower reservoir into the groundwater without sealing. Therefore, in order to reliably predict the impact of the pumped storage plant operations on the surrounding drinking water wells and groundwater dependent ecosystems, a comprehensive database has been developed to assess the hydraulic conditions of the karst aquifer. A large scale geological site investigation was carried out to characterise the rock mass and extensive hydraulic tests were performed in many boreholes. The results of the hydraulic characterisation were then implemented in a three dimensional flow model. In this paper, the first results of the geological and hydrogeological investigations are presented and discussed.

  20. Intergenerationale Transmission von kulturellem Kapital unter Migrationsbedingungen: Zum Bildungserfolg von Kindern und Jugendlichen aus Migrantenfamilien in Deutschland (Intergenerational Transmission of Cultural Capital under the Conditions of Migration--On the Educational Achievement of Children and Adolescents from Migrant Families in Germany).

    ERIC Educational Resources Information Center

    Nauck, Bernhard; Diefenbach, Heike; Petri, Kornelia

    1998-01-01

    Examines the factors that lead to the existing ethnic inequalities within the German educational system. Analyzes, in relation to migration, the significance of the intergenerational transmission of education as cultural capital in combination with economic and social capital. Discusses the findings. (CMK)

  1. Morphometric Analysis of Thyroid Follicular Cells with Atypia of Undetermined Significance

    PubMed Central

    Kang, Youngjin; Lee, Yoo Jin; Jung, Jiyoon; Lee, Youngseok; Won, Nam Hee; Chae, Yang Seok

    2016-01-01

    Background: Atypia of undetermined significance (AUS) is a category that encompasses a heterogeneous group of thyroid aspiration cytology. It has been reclassified into two subgroups based on the cytomorphologic features: AUS with cytologic atypia and AUS with architectural atypia. The nuclear characteristics of AUS with cytologic atypia need to be clarified by comparing to those observed in Hashimoto thyroiditis and benign follicular lesions. Methods: We selected 84 cases of AUS with histologic follow-up, 24 cases of Hashimoto thyroiditis, and 26 cases of benign follicular lesions. We also subcategorized the AUS group according to the follow-up biopsy results into a papillary carcinoma group and a nodular hyperplasia group. The differences in morphometric parameters, including the nuclear areas and perimeters, were compared between these groups. Results: The AUS group had significantly smaller nuclear areas than the Hashimoto thyroiditis group, but the nuclear perimeters were not statistically different. The AUS group also had significantly smaller nuclear areas than the benign follicular lesion group; however, the AUS group had significantly longer nuclear perimeters. The nuclear areas in the papillary carcinoma group were significantly smaller than those in the nodular hyperplasia group; however, the nuclear perimeters were not statistically different. Conclusions: We found the AUS group to be a heterogeneous entity, including histologic follow-up diagnoses of papillary carcinoma and nodular hyperplasia. The AUS group showed significantly greater nuclear irregularities than the other two groups. Utilizing these features, nuclear morphometry could lead to improvements in the accuracy of the subjective diagnoses made with thyroid aspiration cytology. PMID:27292152

  2. Identification of Action Units Related to Affective States in a Tutoring System for Mathematics

    ERIC Educational Resources Information Center

    Padrón-Rivera, Gustavo; Rebolledo-Mendez, Genaro; Parra, Pilar Pozos; Huerta-Pacheco, N. Sofia

    2016-01-01

    Affect is an important element of the learning process both in the classroom and with educational technology. This paper presents analyses in relation to the identification of Action Units (AUs) related to affective states and their impact on learning with a tutoring system. To assess affect, a tool was devised to identify AUs on pictures of human…

  3. TÜV - Zertifizierungen in der Life Science Branche

    NASA Astrophysics Data System (ADS)

    Schaff, Peter; Gerbl-Rieger, Susanne; Kloth, Sabine; Schübel, Christian; Daxenberger, Andreas; Engler, Claus

    Life Sciences [1] (Lebenswissenschaften) sind ein globales Innovationsfeld mit Anwendungen der Bio- und Medizinwissenschaften, der Pharma-, Chemie-, Kosmetik- und Lebensmittelindustrie. Diese Branche zeichnet sich durch eine stark interdisziplinäre Ausrichtung aus, mit Anwendung wissenschaftlicher Erkenntnisse und Einsatz von Ausgangsstoffen aus der modernen Biologie, Chemie und Humanmedizin sowie gezielter marktwirtschaftlich orientierter Arbeit.

  4. Neuropsychological Functioning of Siblings of Children with Autism, Siblings of Children with Developmental Language Delay, and Siblings of Children with Mental Retardation of Unknown Genetic Etiology

    ERIC Educational Resources Information Center

    Pilowsky, Tammy; Yirmiya, Nurit; Gross-Tsur, Varda; Shalev, Ruth S.

    2007-01-01

    Neuropsychological functioning of 30 siblings of children with autism (AU-S), 28 siblings of children with mental retardation of (MR-S), and 30 siblings of children with developmental language delay (DLD-S) was compared. Two siblings, both AU-S, received diagnoses of pervasive developmental disorder (PDD). More siblings with cognitive disabilities…

  5. Crystallization and preliminary crystallographic analysis of latent, active and recombinantly expressed aurone synthase, a polyphenol oxidase, from Coreopsis grandiflora

    PubMed Central

    Molitor, Christian; Mauracher, Stephan Gerhard; Rompel, Annette

    2015-01-01

    Aurone synthase (AUS), a member of a novel group of plant polyphenol oxidases (PPOs), catalyzes the oxidative conversion of chalcones to aurones. Two active cgAUS1 (41.6 kDa) forms that differed in the level of phosphorylation or sulfation as well as the latent precursor form (58.9 kDa) were purified from the petals of Coreopsis grandiflora. The differing active cgAUS1 forms and the latent cgAUS1 as well as recombinantly expressed latent cgAUS1 were crystallized, resulting in six different crystal forms. The active forms crystallized in space groups P212121 and P1211 and diffracted to ∼1.65 Å resolution. Co-crystallization of active cgAUS1 with 1,4-resorcinol led to crystals belonging to space group P3121. The crystals of latent cgAUS1 belonged to space group P1211 and diffracted to 2.50 Å resolution. Co-crystallization of recombinantly expressed pro-AUS with the hexatungstotellurate(VI) salt Na6[TeW6O24] within the liquid–liquid phase separation zone significantly improved the quality of the crystals compared with crystals obtained without hexatungstotellurate(VI). PMID:26057806

  6. Kometen und Asteroiden

    NASA Astrophysics Data System (ADS)

    Borgeest, Ulf; Staude, Jakob; Hahn, Gerhard; Harris, Alan W.; Jaumann, Ralf; Köhler, Ulrich; Kührt, Ekkehard; Schulz, Rita; Neukum, Gerhard; Arnold, Gabriele; Keller, Horst Uwe; Denk, Tilmann; Müller, Thomas; Wulff, André; Maruhn, Nicolaus; Fischer, Daniel; Trieloff, Mario; Althaus, Tilmann

    Contents: Die Kleinkörper des Sonnensystems. Kern, Koma und Schweife. Ziele der Planetenforschung. ROSETTA: Naherkundung von Kometen. Asteroiden: Trümmer aus planetarer Urzeit. Kleinkörper im Infrarotweltall. Selbs beobachten! Apocalypse - not now! Meteoriten - Boten aus der Urzeit des Sonnensystems.

  7. Homology modeling and dynamics study of aureusidin synthase--an important enzyme in aurone biosynthesis of snapdragon flower.

    PubMed

    Elumalai, Pavadai; Liu, Hsuan-Liang

    2011-08-01

    Aurones, a class of plant flavonoids, provide bright yellow color on some important ornamental flowers, such as cosmos, coreopsis, and snapdragon (Antirrhinum majus). Recently, it has been elucidated that aureusidin synthase (AUS), a homolog of plant polyphenol oxidase (PPO), plays a key role in the yellow coloration of snapdragon flowers. In addition, it has been shown that AUS is a chalcone-specific PPO specialized for aurone biosynthesis. AUS gene has been successfully demonstrated as an attractive tool to engineer yellow flowers in blue flowers. Despite these biological studies, the structural basis for the specificity of substrate interactions of AUS remains elusive. In this study, we performed homology modeling of AUS using Grenache PPO and Sweet potato catechol oxidase (CO). An AUS-inhibitor was then developed from the initial homology model based on the CO and subsequently validated. We performed a thorough study between AUS and PTU inhibitor by means of interaction energy, which indicated the most important residues in the active site that are highly conserved. Analysis of the molecular dynamics simulations of the apo enzyme and ligand-bound complex showed that complex is relatively stable than apo and the active sites of both systems are flexible. The results from this study provide very helpful information to understand the structure-function relationships of AUS. PMID:21470561

  8. Hormonsystem

    NASA Astrophysics Data System (ADS)

    Spindler-Barth, Margarethe

    Hormone werden in spezialisierten Zellen gebildet, die häufig zu Drüsen zusammengefasst sind. Sie gelangen über die Blutbahn (endokrine Sekretion) bzw. durch Diffusion (parakrine oder autokrine Sekretion) zu ihrem Wirkort. Nach ihrer chemischen Struktur unterscheidet man Peptidhormone, also von Aminosäuren abgeleitete Hormone und Steroid hormone (S. 144, Tabelle 3). In einem vielzelligen Organismus dienen Hormone der Koordination und Regulation von zahlreichen Funktionen (Homöostase, Reproduktion, Verhalten). Hormonproduzierende Drüsen (Abb. 134) gehen aus jedem der drei Keimblätter hervor, z. B. Hypothalamus und Nebennierenmark aus dem Ektoderm, Nebennierenrinde und Gonaden aus dem Mesoderm, Schilddrüse und Inselgewebe (Pankreas) aus dem Entoderm. Häufig werden die Organe aus zwei unterschiedlichen Geweben (Nerven- und Epithelzellen) gebildet. Auffallend sind ferner Abwandlungen der ursprünglich epithelialen Anteile (z. B. Nebennierenrinde, Adenohypophyse).

  9. Crystallization and preliminary crystallographic analysis of latent, active and recombinantly expressed aurone synthase, a polyphenol oxidase, from Coreopsis grandiflora

    SciTech Connect

    Molitor, Christian; Mauracher, Stephan Gerhard; Rompel, Annette

    2015-05-22

    Latent and active aurone synthase purified from petals of C. grandiflora (cgAUS1) were crystallized. The crystal quality of recombinantly expressed latent cgAUS1 was significantly improved by co-crystallization with the polyoxotungstate Na{sub 6}[TeW{sub 6}O{sub 24}] within the liquid–liquid phase-separation zone. Aurone synthase (AUS), a member of a novel group of plant polyphenol oxidases (PPOs), catalyzes the oxidative conversion of chalcones to aurones. Two active cgAUS1 (41.6 kDa) forms that differed in the level of phosphorylation or sulfation as well as the latent precursor form (58.9 kDa) were purified from the petals of Coreopsis grandiflora. The differing active cgAUS1 forms and the latent cgAUS1 as well as recombinantly expressed latent cgAUS1 were crystallized, resulting in six different crystal forms. The active forms crystallized in space groups P2{sub 1}2{sub 1}2{sub 1} and P12{sub 1}1 and diffracted to ∼1.65 Å resolution. Co-crystallization of active cgAUS1 with 1,4-resorcinol led to crystals belonging to space group P3{sub 1}21. The crystals of latent cgAUS1 belonged to space group P12{sub 1}1 and diffracted to 2.50 Å resolution. Co-crystallization of recombinantly expressed pro-AUS with the hexatungstotellurate(VI) salt Na{sub 6}[TeW{sub 6}O{sub 24}] within the liquid–liquid phase separation zone significantly improved the quality of the crystals compared with crystals obtained without hexatungstotellurate(VI)

  10. Bioenergetic constraints for conversion of syngas to biofuels in acetogenic bacteria.

    PubMed

    Bertsch, Johannes; Müller, Volker

    2015-01-01

    Synthesis gas (syngas) is a gas mixture consisting mainly of H2, CO, and CO2 and can be derived from different sources, including renewable materials like lignocellulose. The fermentation of syngas to certain biofuels, using acetogenic bacteria, has attracted more and more interest over the last years. However, this technology is limited by two things: (1) the lack of complete knowledge of the energy metabolism of acetogenic bacteria, and (2) the lack of sophisticated genetic tools for the modification of acetogens. In this review, we discuss the bioenergetic constraints for the conversion of syngas to different biofuels. We will mainly focus on Acetobacterium woodii, which is the best understood acetogen in terms of energy conservation. Syngas fermentation with Clostridium autoethanogenum will also be discussed, since this organism is well suited to convert syngas to certain products and already used in large-scale industrial processes. PMID:26692897

  11. Occurrence of ferredoxin:NAD+ oxidoreductase activity and its ion specificity in several Gram-positive and Gram-negative bacteria

    PubMed Central

    Hess, Verena; Gallegos, Rene; Jones, J Andrew; Barquera, Blanca; Malamy, Michael H

    2016-01-01

    A ferredoxin:NAD+ oxidoreductase was recently discovered as a redox-driven ion pump in the anaerobic, acetogenic bacterium Acetobacterium woodii. The enzyme is assumed to be encoded by the rnf genes. Since these genes are present in the genomes of many bacteria, we tested for ferredoxin:NAD+ oxidoreductase activity in cytoplasmic membranes from several different Gram-positive and Gram-negative bacteria that have annotated rnf genes. We found this activity in Clostridium tetanomorphum, Clostridium ljungdahlii, Bacteroides fragilis, and Vibrio cholerae but not in Escherichia coli and Rhodobacter capsulatus. As in A. woodii, the activity was Na+-dependent in C. tetanomorphum and B. fragilis but Na+-independent in C. ljungdahlii and V. cholerae. We deleted the rnf genes from B. fragilis and demonstrated that the mutant has greatly reduced ferredoxin:NAD+ oxidoreductase activity. This is the first genetic proof that the rnf genes indeed encode the reduced ferredoxin:NAD+ oxidoreductase activity. PMID:26793417

  12. Carbon isotope effects associated with autotrophic acetogenesis

    USGS Publications Warehouse

    Gelwicks, J.T.; Risatti, J.B.; Hayes, J.M.

    1989-01-01

    The carbon kinetic isotope effects associated with synthesis of acetate from CO2 and H2 during autotrophic growth of Acetobacterium woodii at 30??C have been measured by isotopic analyses of CO2, methyl-carbon, and total acetate. Closed systems allowing construction of complete mass balances at varying stages of growth were utilized, and the effects of the partitioning of carbon between CO2 and HCO3- were taken into account. For the overall reaction, total carbonate ??? total acetate, isotope effects measured in replicate experiments ranged from -59.0 ?? 0.9% to - 57.2 ?? 2.3z%. Taking into account all measurements, the weighted mean and standard deviation are -58.6 ?? 0.7%. There is no evidence for intramolecular ordering in the acetate. The carbon isotopic composition of sedimentary acetate, otherwise expected to be near that of sedimentary organic carbon, is likely to be depleted in environments in which autotrophic acetogenesis is occurring. ?? 1989.

  13. The interaction of plutonium with bacteria in the repository environment

    NASA Astrophysics Data System (ADS)

    Gillow, J. B.; Francis, A. J.; Lucero, D. A.; Papenguth, H. W.

    2000-07-01

    Microorganisms in the nuclear waste repository environment may interact with plutonium through (i) sorption, (ii) intracellular accumulation, and (iii) transformation of chemical speciation. These interactions may retard or enhance the mobility of Pu by precipitation reactions, biocolloid formation, or production of more soluble species. Current and planned radioactive waste repository environments, such as deep subsurface halite and granite formations, are considered extreme relative to life processes in the near-surface terrestrial environment. There is a paucity of information on the biotransformation of radionuclides by microorganisms present in such extreme environments. In order to gain a better understanding of the interaction of plutonium with microorganisms present in the waste repository sites we investigated a pure culture (Halomonas sp.) and a mixed culture of bacteria (Haloarcula sinaiiensis, Marinobacter hydrocarbonoclasticus, Altermonas sp., and a g-proteobacterium) isolated from the Waste Isolation Pilot Plant (WIPP) site and an Acetobacterium sp. from alkaline groundwater at the Grimsel Test Site in Switzerland.

  14. Interaction of Plutonium with Bacteria in the Repository Environment

    SciTech Connect

    Gillow, J. B.; Francis, A. J.; Lucero, D. A.; Papenguth, H. W.

    2000-07-01

    Microorganisms in the nuclear waste repository environment may interact with plutonium through (1) sorption, (2) intracellular accumulation, and (3) transformation speciation. These interactions may retard or enhance the mobility of Pu by precipitation reactions, biocolloid formation, or production of more soluble species. Current and planned radioactive waste repository environments, such as deep subsurface halite and granite formations, are considered extreme relative to life processes in the near-surface terrestrial environment. There is a paucity of information on the biotransformation of radionuclides by microorganisms present in such extreme environments. In order to gain a better understanding of the interaction of plutonium with microorganisms present in the waste repository sites we investigated a pure culture (Halomonas sp.) and a mixed culture of bacteria (Haloarcula sinaiiensis, Marinobacter hydrocarbonoclasticus, Altermonas sp., and a {gamma}-proteobacterium) isolated from the Waste Isolation Pilot Plant (WIPP) site and an Acetobacterium sp. from alkaline groundwater at the Grimsel Test Site in Switzerland.

  15. Recalcitrance of 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) to cometabolic degradation by pure cultures of aerobic and anaerobic bacteria.

    PubMed

    Megharaj, M; Jovcic, A; Boul, H L; Thiele, J H

    1997-08-01

    Pure cultures of aerobic and anaerobic bacteria capable of oxidation and reductive dehalogenation of chloroethylenes, and aerobic bacteria involved in biodegradation of polychlorinated biphenyls (PCBs) were screened for their ability to cometabolize the persistent pollutant 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE). Bacterial cultures expressing methane monooxygenase (Methylosinus trichosporium), propane monooxygenase (Mycobacterium vaccae) and biphenyl 2,3-dioxygenase enzymes (Pseudomonas fluorescens and Rhodococcus globerulus), as well as bacteria reductively dechlorinating chloroethylenes (Acetobacterium woodii and Clostridium butyricum) could not degrade DDE. Cell-free extracts of M. trichosporium, M. vaccae, P. fluorescens and R. globerulus were also unable to transform DDE, indicating that cell wall and membrane diffusion barriers were not biodegradation limiting. These studies suggest that these bacteria can not degrade DDE, even when provided with cosubstrates that induce chlorophenyl- and dichloroethylene-group transforming enzymes. PMID:9294241

  16. Natural transfer of conjugative transposon Tn916 between gram-positive and gram-negative bacteria.

    PubMed

    Bertram, J; Strätz, M; Dürre, P

    1991-01-01

    The conjugative streptococcal transposon Tn916 was found to transfer naturally between a variety of gram-positive and gram-negative eubacteria. Enterococcus faecalis hosting the transposon could serve as a donor for Alcaligenes eutrophus, Citrobacter freundii, and Escherichia coli at frequencies of 10(-6) to 10(-8). No transfer was observed with several phototrophic species. Mating of an E. coli strain carrying Tn916 yielded transconjugants with Bacillus subtilis, Clostridium acetobutylicum, Enterococcus faecalis, and Streptococcus lactis subsp. diacetylactis at frequencies of 10(-4) to 10(-6). Acetobacterium woodii was the only gram-positive organism tested that did not accept the transposon from a gram-negative donor. The results prove the ability of conjugative transposable elements such as Tn916 for natural cross-species gene transfer, thus potentially contributing to bacterial evolution. PMID:1846142

  17. Effect of solvents on obligately anaerobic bacteria.

    PubMed

    Rodriguez Martinez, Maria Fernanda; Kelessidou, Niki; Law, Zoe; Gardiner, John; Stephens, Gill

    2008-02-01

    Growth of Acetobacterium woodii and Clostridium sporogenes was studied in the presence of water-immiscible solvents. Nitrogen purging, vacuum distillation or distillation under nitrogen were all suitable as methods to remove oxygen from the solvents, since growth rates and yields of A. woodii were unaffected in the presence of tetradecane which had been degassed by these methods. Varying the solvent volume from 20% to 80% of the culture volume had little effect on growth rate of A. woodii. A.woodii was relatively sensitive to organic solvents since growth was inhibited by alkanes with logP(octanol/water) values below 7.1. C. sporogenes was less solvent sensitive, since it grew without inhibition when the logP of the solvent was > or = 6.6. Nevertheless, both A. woodii and C. sporogenes were more sensitive to solvent polarity than aerobic bacteria. PMID:18083050

  18. Production of acetate from carbon dioxide in bioelectrochemical systems based on autotrophic mixed culture.

    PubMed

    Su, Min; Jiang, Yong; Li, Daping

    2013-08-01

    Bioelectrochemical systems (BESs) have been suggested as a new technology for wastewater treatment while accomplishing energy and chemical generation. This study describes the performance of BESs based on mixed culture that are capable of reducing carbon dioxide to acetate. The cathode potential was a critical factor that affected the performance of the BESs. The rate of acetate production increased as the electrode potential became more negative, from 0.38 mM d(-1) (-900 mV vs. Ag/AgCl) to 2.35 mM d(-1) (-1,100 mV), while the electron recovery efficiency of carbon dioxide reduction to acetate increased from 53.6% to 89.5%. The microbial population was dominated by relatives of Acetobacterium woodii when a methanogenic inhibitor was added to the BESs initially. PMID:23727797

  19. Direct and reversible hydrogenation of CO2 to formate by a bacterial carbon dioxide reductase.

    PubMed

    Schuchmann, K; Müller, V

    2013-12-13

    Storage and transportation of hydrogen is a major obstacle for its use as a fuel. An increasingly considered alternative for the direct handling of hydrogen is to use carbon dioxide (CO2) as an intermediate storage material. However, CO2 is thermodynamically stable, and developed chemical catalysts often require high temperatures, pressures, and/or additives for high catalytic rates. Here, we present the discovery of a bacterial hydrogen-dependent carbon dioxide reductase from Acetobacterium woodii directly catalyzing the hydrogenation of CO2. We also demonstrate a whole-cell system able to produce formate as the sole end product from dihydrogen (H2) and CO2 as well as syngas. This discovery opens biotechnological alternatives for efficient CO2 hydrogenation either by using the isolated enzyme or by employing whole-cell catalysis. PMID:24337298

  20. An ancient pathway combining carbon dioxide fixation with the generation and utilization of a sodium ion gradient for ATP synthesis.

    PubMed

    Poehlein, Anja; Schmidt, Silke; Kaster, Anne-Kristin; Goenrich, Meike; Vollmers, John; Thürmer, Andrea; Bertsch, Johannes; Schuchmann, Kai; Voigt, Birgit; Hecker, Michael; Daniel, Rolf; Thauer, Rudolf K; Gottschalk, Gerhard; Müller, Volker

    2012-01-01

    Synthesis of acetate from carbon dioxide and molecular hydrogen is considered to be the first carbon assimilation pathway on earth. It combines carbon dioxide fixation into acetyl-CoA with the production of ATP via an energized cell membrane. How the pathway is coupled with the net synthesis of ATP has been an enigma. The anaerobic, acetogenic bacterium Acetobacterium woodii uses an ancient version of this pathway without cytochromes and quinones. It generates a sodium ion potential across the cell membrane by the sodium-motive ferredoxin:NAD oxidoreductase (Rnf). The genome sequence of A. woodii solves the enigma: it uncovers Rnf as the only ion-motive enzyme coupled to the pathway and unravels a metabolism designed to produce reduced ferredoxin and overcome energetic barriers by virtue of electron-bifurcating, soluble enzymes. PMID:22479398

  1. Occurrence of ferredoxin:NAD(+) oxidoreductase activity and its ion specificity in several Gram-positive and Gram-negative bacteria.

    PubMed

    Hess, Verena; Gallegos, Rene; Jones, J Andrew; Barquera, Blanca; Malamy, Michael H; Müller, Volker

    2016-01-01

    A ferredoxin:NAD(+) oxidoreductase was recently discovered as a redox-driven ion pump in the anaerobic, acetogenic bacterium Acetobacterium woodii. The enzyme is assumed to be encoded by the rnf genes. Since these genes are present in the genomes of many bacteria, we tested for ferredoxin:NAD(+) oxidoreductase activity in cytoplasmic membranes from several different Gram-positive and Gram-negative bacteria that have annotated rnf genes. We found this activity in Clostridium tetanomorphum, Clostridium ljungdahlii, Bacteroides fragilis, and Vibrio cholerae but not in Escherichia coli and Rhodobacter capsulatus. As in A. woodii, the activity was Na(+)-dependent in C. tetanomorphum and B. fragilis but Na(+)-independent in C. ljungdahlii and V. cholerae. We deleted the rnf genes from B. fragilis and demonstrated that the mutant has greatly reduced ferredoxin:NAD(+) oxidoreductase activity. This is the first genetic proof that the rnf genes indeed encode the reduced ferredoxin:NAD(+) oxidoreductase activity. PMID:26793417

  2. Carbon isotope effects associated with autotrophic acetogenesis.

    PubMed

    Gelwicks, J T; Risatti, J B; Hayes, J M

    1989-01-01

    The carbon kinetic isotope effects associated with synthesis of acetate from CO2 and H2 during autotrophic growth of Acetobacterium woodii at 30 degrees C have been measured by isotopic analyses of CO2, methyl-carbon, and total acetate. Closed systems allowing construction of complete mass balances at varying stages of growth were utilized, and the effects of the partitioning of carbon between CO2 and HCO3- were taken account. For the overall reaction, total carbonate --> total acetate, isotope effects measured in replicate experiments ranged from -59.0 +/- 0.9% to -57.2 +/- 2.3%. Taking into account all measurements, the weighted mean and standard deviation are -58.6 +/- 0.7%. There is no evidence for intramolecular ordering in the acetate. The carbon isotopic composition of sedimentary acetate, otherwise expected to be near that of sedimentary organic carbon, is likely to be depleted in environments in which autotrophic acetogenesis is occurring. PMID:11542159

  3. Respiratory chain supercomplexes.

    PubMed

    Schägger, H

    2001-01-01

    Respiratory chain supercomplexes have been isolated from mammalian and yeast mitochondria, and bacterial membranes. Functional roles of respiratory chain supercomplexes are catalytic enhancement, substrate channelling, and stabilization of complex I by complex III in mammalian cells. Bacterial supercomplexes are characterized by their relatively high detergent-stability compared to yeast or mammalian supercomplexes that are stable to sonication. The mobility of substrate cytochrome c increases in the order bacterial, yeast, and mammalian respiratory chain. In bacterial supercomplexes, the electron transfer between complexes III and IV involves movement of the mobile head of a tightly bound cytochrome c, whereas the yeast S. cerevisiae seems to use substrate channelling of a mobile cytochrome c, and mammalian respiratory chains have been described to use a cytochrome c pool. Dimeric ATP synthase seems to be specific for mitochondrial OXPHOS systems. Monomeric complex V was found in Acetobacterium woodii and Paracoccus denitrificans. PMID:11798023

  4. Carbon isotope effects associated with autotrophic acetogenesis

    NASA Technical Reports Server (NTRS)

    Gelwicks, J. T.; Risatti, J. B.; Hayes, J. M.

    1989-01-01

    The carbon kinetic isotope effects associated with synthesis of acetate from CO2 and H2 during autotrophic growth of Acetobacterium woodii at 30 degrees C have been measured by isotopic analyses of CO2, methyl-carbon, and total acetate. Closed systems allowing construction of complete mass balances at varying stages of growth were utilized, and the effects of the partitioning of carbon between CO2 and HCO3- were taken account. For the overall reaction, total carbonate --> total acetate, isotope effects measured in replicate experiments ranged from -59.0 +/- 0.9% to -57.2 +/- 2.3%. Taking into account all measurements, the weighted mean and standard deviation are -58.6 +/- 0.7%. There is no evidence for intramolecular ordering in the acetate. The carbon isotopic composition of sedimentary acetate, otherwise expected to be near that of sedimentary organic carbon, is likely to be depleted in environments in which autotrophic acetogenesis is occurring.

  5. An Ancient Pathway Combining Carbon Dioxide Fixation with the Generation and Utilization of a Sodium Ion Gradient for ATP Synthesis

    PubMed Central

    Poehlein, Anja; Schmidt, Silke; Kaster, Anne-Kristin; Goenrich, Meike; Vollmers, John; Thürmer, Andrea; Bertsch, Johannes; Schuchmann, Kai; Voigt, Birgit; Hecker, Michael; Daniel, Rolf; Thauer, Rudolf K.; Gottschalk, Gerhard; Müller, Volker

    2012-01-01

    Synthesis of acetate from carbon dioxide and molecular hydrogen is considered to be the first carbon assimilation pathway on earth. It combines carbon dioxide fixation into acetyl-CoA with the production of ATP via an energized cell membrane. How the pathway is coupled with the net synthesis of ATP has been an enigma. The anaerobic, acetogenic bacterium Acetobacterium woodii uses an ancient version of this pathway without cytochromes and quinones. It generates a sodium ion potential across the cell membrane by the sodium-motive ferredoxin:NAD oxidoreductase (Rnf). The genome sequence of A. woodii solves the enigma: it uncovers Rnf as the only ion-motive enzyme coupled to the pathway and unravels a metabolism designed to produce reduced ferredoxin and overcome energetic barriers by virtue of electron-bifurcating, soluble enzymes. PMID:22479398

  6. Fermentative degradation of nonionic surfactants and polyethylene glycol by enrichment cultures and by pure cultures of homoacetogenic and propionate-forming bacteria.

    PubMed Central

    Wagener, S; Schink, B

    1988-01-01

    Linear alkyl ethoxylates (polyethylene glycol alkyl ethers) were fermented completely to methane and CO2 in enrichment cultures inoculated with anoxic sewage sludge. Long-chain fatty acids were released as intermediates. No degradation was found with polypropylene glycol and polypropylene glycol-containing surfactants. Two types of primary ethoxylate-degrading bacteria were isolated and characterized. Both degraded polyethylene glycols with molecular weights of 1,000 completely. Strain KoB35 fermented polyethylene glycol, ethoxyethanol, and lactate to acetate and propionate and was assigned to the described species Pelobacter propionicus. Strain KoB58 converted polyethylene glycol and many other substrates to acetate only and was assigned to the genus Acetobacterium. The pathways of anaerobic degradation of nonionic surfactants are discussed with respect to their limitations and the various groups of bacteria involved. Images PMID:3355141

  7. Artificial urinary sphincters for male stress urinary incontinence: current perspectives

    PubMed Central

    Cordon, Billy H; Singla, Nirmish; Singla, Ajay K

    2016-01-01

    The artificial urinary sphincter (AUS), which has evolved over many years, has become a safe and reliable treatment for stress urinary incontinence and is currently the gold standard. After 4 decades of existence, there is substantial experience with the AUS. Today AUS is most commonly placed for postprostatectomy stress urinary incontinence. Only a small proportion of urologists routinely place AUS. In a survey in 2005, only 4% of urologists were considered high-volume AUS implanters, performing >20 per year. Globally, ~11,500 AUSs are placed annually. Over 400 articles have been published regarding the outcomes of AUS, with a wide variance in success rates ranging from 61% to 100%. Generally speaking, the AUS has good long-term outcomes, with social continence rates of ~79% and high patient satisfaction usually between 80% and 90%. Despite good outcomes, a substantial proportion of patients, generally ~25%, will require revision surgery, with the rate of revision increasing with time. Complications requiring revision include infection, urethral atrophy, erosion, and mechanical failure. Most infections are gram-positive skin flora. Urethral atrophy and erosion lie on a spectrum resulting from the same problem, constant urethral compression. However, these two complications are managed differently. Mechanical failure is usually a late complication occurring on average later than infection, atrophy, or erosions. Various techniques may be used during revisions, including cuff relocation, downsizing, transcorporal cuff placement, or tandem cuff placement. Patient satisfaction does not appear to be affected by the need for revision as long as continence is restored. Additionally, AUS following prior sling surgery has comparable outcomes to primary AUS placement. Several new inventions are on the horizon, although none have been approved for use in the US at this point. PMID:27445509

  8. Stemming the tide of mild to moderate post-prostatectomy incontinence: A retrospective comparison of transobturator male slings and the artificial urinary sphincter

    PubMed Central

    Hoy, Nathan Y.; Rourke, Keith F.

    2014-01-01

    Introduction: The AUS remains the gold standard treatment for post-prostatectomy incontinence (PPI), although most patients with mild-moderate PPI prefer a sling without strong evidence of procedural equivalence. This study compares outcomes of 2 procedures for the treatment of mild-moderate PPI. Methods: A retrospective review of 124 patients (76 transobturator sling, 48 AUS) with mild-moderate PPI requiring intervention over an 8-year period. The primary outcome was continence. Secondary outcomes included global patient satisfaction, improvement, and complication rates. Mild to moderate incontinence was defined as requiring ≤5 pads/day. Results: There was no significant difference in age (66.2 vs. 68.1 years; p = 0.17) or prostate cancer characteristics for slings and AUS, respectively. AUS patients had higher Charlson comorbidity scores and were more likely to have previous radiotherapy. Median length of follow up was 24 months for slings and 42 months for AUS. There was no difference in continence rates, 88.2% vs. 87.5% (p = 0.79), rate of improvement, 94.7% vs. 95.8% (p = 1.00), or patient satisfaction, 93.4% vs. 91.7% (p = 0.73), for slings and AUS, respectively. Complication rates were equivalent (19.7% vs. 16.7%; p = 1.00), though a significantly higher proportion of complications with AUS were Clavien Grade 3 (0% vs. 75%; p = 0.006). Conclusions: For mild to moderate PPI there is no difference in continence, satisfaction, or improvement rates, between AUS and slings. AUS complications tend to be more severe. Our study supports the use of slings as first-line treatment for mild-moderate PPI. PMID:25210552

  9. Ecological relevance of current water quality assessment unit designations in impaired rivers.

    PubMed

    Layhee, Megan; Sepulveda, Adam; Ray, Andrew; Mladenka, Greg; Van Every, Lynn

    2015-12-01

    Managers often nest sections of water bodies together into assessment units (AUs) to monitor and assess water quality criteria. Ideally, AUs represent an extent of waters with similar ecological, watershed, habitat and land-use conditions and no overlapping characteristics with other waters. In the United States, AUs are typically based on political or hydrologic boundaries rather than on ecologically relevant features, so it can be difficult to detect changes in impairment status. Our goals were to evaluate if current AU designation criteria of an impaired water body in southeastern Idaho, USA that, like many U.S. waters, has three-quarters of its mainstem length divided into two AUs. We focused our evaluation in southeastern Idaho's Portneuf River, an impaired river and three-quarters of the river is divided into two AUs. We described biological and environmental conditions at multiple reaches within each AU. We used these data to (1) test if variability at the reach-scale is greater within or among AUs and, (2) to evaluate alternate AU boundaries based on multivariate analyses of reach-scale data. We found that some biological conditions had greater variability within an AU than between AUs. Multivariate analyses identified alternative, 2- and 3-group, AUs that reduced this variability. Our results suggest that the current AU designations in the mainstem Portneuf River contain ecologically distinct sections of river and that the existing AU boundaries should be reconsidered in light of the ecological conditions measured at the reach scale. Variation in biological integrity within designated AUs may complicate water quality and biological assessments, influence management decisions or affect where monitoring or mitigation resources are directed. PMID:26210354

  10. Ecological relevance of current water quality assessment unit designations in impaired rivers

    USGS Publications Warehouse

    Layhee, Megan J.; Sepulveda, Adam; Ray, Andrew; Mladenka, Greg; Van Every, Lynn

    2016-01-01

    Managers often nest sections of water bodies together into assessment units (AUs) to monitor and assess water quality criteria. Ideally, AUs represent an extent of waters with similar ecological, watershed, habitat and land-use conditions and no overlapping characteristics with other waters. In the United States, AUs are typically based on political or hydrologic boundaries rather than on ecologically relevant features, so it can be difficult to detect changes in impairment status. Our goals were to evaluate if current AU designation criteria of an impaired water body in southeastern Idaho, USA that, like many U.S. waters, has three-quarters of its mainstem length divided into two AUs. We focused our evaluation in southeastern Idaho's Portneuf River, an impaired river and three-quarters of the river is divided into two AUs. We described biological and environmental conditions at multiple reaches within each AU. We used these data to (1) test if variability at the reach-scale is greater within or among AUs and, (2) to evaluate alternate AU boundaries based on multivariate analyses of reach-scale data. We found that some biological conditions had greater variability within an AU than between AUs. Multivariate analyses identified alternative, 2- and 3-group, AUs that reduced this variability. Our results suggest that the current AU designations in the mainstem Portneuf River contain ecologically distinct sections of river and that the existing AU boundaries should be reconsidered in light of the ecological conditions measured at the reach scale. Variation in biological integrity within designated AUs may complicate water quality and biological assessments, influence management decisions or affect where monitoring or mitigation resources are directed.

  11. The role of acetogens in microbially influenced corrosion of steel

    PubMed Central

    Mand, Jaspreet; Park, Hyung Soo; Jack, Thomas R.; Voordouw, Gerrit

    2014-01-01

    Microbially influenced corrosion (MIC) of iron (Fe0) by sulfate-reducing bacteria (SRB) has been studied extensively. Through a mechanism, that is still poorly understood, electrons or hydrogen (H2) molecules are removed from the metal surface and used as electron donor for sulfate reduction. The resulting ferrous ions precipitate in part with the sulfide produced, forming characteristic black iron sulfide. Hydrogenotrophic methanogens can also contribute to MIC. Incubation of pipeline water samples, containing bicarbonate and some sulfate, in serum bottles with steel coupons and a headspace of 10% (vol/vol) CO2 and 90% N2, indicated formation of acetate and methane. Incubation of these samples in serum bottles, containing medium with coupons and bicarbonate but no sulfate, also indicated that formation of acetate preceded the formation of methane. Microbial community analyses of these enrichments indicated the presence of Acetobacterium, as well as of hydrogenotrophic and acetotrophic methanogens. The formation of acetate by homoacetogens, such as Acetobacterium woodii from H2 (or Fe0) and CO2, is potentially important, because acetate is a required carbon source for many SRB growing with H2 and sulfate. A consortium of the SRB Desulfovibrio vulgaris Hildenborough and A. woodii was able to grow in defined medium with H2, CO2, and sulfate, because A. woodii provides the acetate, needed by D. vulgaris under these conditions. Likewise, general corrosion rates of metal coupons incubated with D. vulgaris in the presence of acetate or in the presence of A. woodii were higher than in the absence of acetate or A. woodii, respectively. An extended MIC model capturing these results is presented. PMID:24917861

  12. Molecular Characterization of a Dechlorinating Community Resulting from In Situ Biostimulation in a Trichloroethene-Contaminated Deep, Fractured Basalt Aquifer and Comparison to a Derivative Laboratory Culture

    PubMed Central

    Macbeth, Tamzen W.; Cummings, David E.; Spring, Stefan; Petzke, Lynn M.; Sorenson, Kent S.

    2004-01-01

    Sodium lactate additions to a trichloroethene (TCE) residual source area in deep, fractured basalt at a U.S. Department of Energy site have resulted in the enrichment of the indigenous microbial community, the complete dechlorination of nearly all aqueous-phase TCE to ethene, and the continued depletion of the residual source since 1999. The bacterial and archaeal consortia in groundwater obtained from the residual source were assessed by using PCR-amplified 16S rRNA genes. A clone library of bacterial amplicons was predominated by those from members of the class Clostridia (57 of 93 clones), of which a phylotype most similar to that of the homoacetogen Acetobacterium sp. strain HAAP-1 was most abundant (32 of 93 clones). The remaining Bacteria consisted of phylotypes affiliated with Sphingobacteria, Bacteroides, Spirochaetes, Mollicutes, and Proteobacteria and candidate divisions OP11 and OP3. The two proteobacterial phylotypes were most similar to those of the known dechlorinators Trichlorobacter thiogenes and Sulfurospirillum multivorans. Although not represented by the bacterial clones generated with broad-specificity bacterial primers, a Dehalococcoides-like phylotype was identified with genus-specific primers. Only four distinct phylotypes were detected in the groundwater archaeal library, including predominantly a clone affiliated with the strictly acetoclastic methanogen Methanosaeta concilii (24 of 43 clones). A mixed culture that completely dechlorinates TCE to ethene was enriched from this groundwater, and both communities were characterized by terminal restriction fragment length polymorphism (T-RFLP). According to T-RFLP, the laboratory enrichment community was less diverse overall than the groundwater community, with 22 unique phylotypes as opposed to 43 and a higher percentage of Clostridia, including the Acetobacterium population. Bioreactor archaeal structure was very similar to that of the groundwater community, suggesting that methane is

  13. Metabolism of the 18O-methoxy substituent of 3-methoxybenzoic acid and other unlabeled methoxybenzoic acids by anaerobic bacteria.

    PubMed

    DeWeerd, K A; Saxena, A; Nagle, D P; Suflita, J M

    1988-05-01

    O-methyl substituents of aromatic compounds can provide C1 growth substrates for facultative and strict anaerobic bacteria isolated from diverse environments. The mechanism of the bioconversion of methoxylated benzoic acids to the hydroxylated derivatives was investigated with a model substrate and cultures of one anaerobic consortium, eight strict anaerobic bacteria, and one facultative anaerobic microorganism. Using high-pressure liquid chromatography and gas chromatography-mass spectral analysis, we found that a haloaromatic dehalogenating consortium, a dehalogenating isolate from that consortium, Eubacterium limosum, and a strain of Acetobacterium woodii metabolized 3-[methoxy-18O]methoxybenzoic acid (3-anisic acid) to 3-[hydroxy-18O]hydroxybenzoic acid stoichiometrically at rates of 1.5, 3.2, 52.4, and 36.7 nmol/min per mg of protein, respectively. A different strain of Acetobacterium and strains of Syntrophococcus, Clostridium, Desulfotomaculum, Enterobacter, and an anaerobic bacterium, strain TH-001, were unable to transform this compound. The O-demethylating ability of E. limosum was induced only with appropriate methoxylated benzoates but not with D-glucose, lactate, isoleucine, or methanol. Cross-acclimation and growth experiments with E. limosum showed a rate of metabolism that was an order of magnitude slower and showed no growth with either 4-methoxysalicylic acid (2-hydroxy-4-methoxybenzoic acid) or 4-anisic acid (4-methoxybenzoic acid) when adapted to 3-anisic acid. However, A. woodii NZva-16 showed slower rates and no growth with 3- or 4-methoxysalicylic acid when adapted to 3-anisic acid in similar experiments. The results clearly indicate a methyl rather than methoxy group removal mechanism for such reactions. PMID:3389815

  14. Metabolism of the 18O-methoxy substituent of 3-methoxybenzoic acid and other unlabeled methoxybenzoic acids by anaerobic bacteria.

    PubMed Central

    DeWeerd, K A; Saxena, A; Nagle, D P; Suflita, J M

    1988-01-01

    O-methyl substituents of aromatic compounds can provide C1 growth substrates for facultative and strict anaerobic bacteria isolated from diverse environments. The mechanism of the bioconversion of methoxylated benzoic acids to the hydroxylated derivatives was investigated with a model substrate and cultures of one anaerobic consortium, eight strict anaerobic bacteria, and one facultative anaerobic microorganism. Using high-pressure liquid chromatography and gas chromatography-mass spectral analysis, we found that a haloaromatic dehalogenating consortium, a dehalogenating isolate from that consortium, Eubacterium limosum, and a strain of Acetobacterium woodii metabolized 3-[methoxy-18O]methoxybenzoic acid (3-anisic acid) to 3-[hydroxy-18O]hydroxybenzoic acid stoichiometrically at rates of 1.5, 3.2, 52.4, and 36.7 nmol/min per mg of protein, respectively. A different strain of Acetobacterium and strains of Syntrophococcus, Clostridium, Desulfotomaculum, Enterobacter, and an anaerobic bacterium, strain TH-001, were unable to transform this compound. The O-demethylating ability of E. limosum was induced only with appropriate methoxylated benzoates but not with D-glucose, lactate, isoleucine, or methanol. Cross-acclimation and growth experiments with E. limosum showed a rate of metabolism that was an order of magnitude slower and showed no growth with either 4-methoxysalicylic acid (2-hydroxy-4-methoxybenzoic acid) or 4-anisic acid (4-methoxybenzoic acid) when adapted to 3-anisic acid. However, A. woodii NZva-16 showed slower rates and no growth with 3- or 4-methoxysalicylic acid when adapted to 3-anisic acid in similar experiments. The results clearly indicate a methyl rather than methoxy group removal mechanism for such reactions. PMID:3389815

  15. The role of acetogens in microbially influenced corrosion of steel.

    PubMed

    Mand, Jaspreet; Park, Hyung Soo; Jack, Thomas R; Voordouw, Gerrit

    2014-01-01

    Microbially influenced corrosion (MIC) of iron (Fe(0)) by sulfate-reducing bacteria (SRB) has been studied extensively. Through a mechanism, that is still poorly understood, electrons or hydrogen (H2) molecules are removed from the metal surface and used as electron donor for sulfate reduction. The resulting ferrous ions precipitate in part with the sulfide produced, forming characteristic black iron sulfide. Hydrogenotrophic methanogens can also contribute to MIC. Incubation of pipeline water samples, containing bicarbonate and some sulfate, in serum bottles with steel coupons and a headspace of 10% (vol/vol) CO2 and 90% N2, indicated formation of acetate and methane. Incubation of these samples in serum bottles, containing medium with coupons and bicarbonate but no sulfate, also indicated that formation of acetate preceded the formation of methane. Microbial community analyses of these enrichments indicated the presence of Acetobacterium, as well as of hydrogenotrophic and acetotrophic methanogens. The formation of acetate by homoacetogens, such as Acetobacterium woodii from H2 (or Fe(0)) and CO2, is potentially important, because acetate is a required carbon source for many SRB growing with H2 and sulfate. A consortium of the SRB Desulfovibrio vulgaris Hildenborough and A. woodii was able to grow in defined medium with H2, CO2, and sulfate, because A. woodii provides the acetate, needed by D. vulgaris under these conditions. Likewise, general corrosion rates of metal coupons incubated with D. vulgaris in the presence of acetate or in the presence of A. woodii were higher than in the absence of acetate or A. woodii, respectively. An extended MIC model capturing these results is presented. PMID:24917861

  16. A Dechlorinating Community Resulting From In Situ Biostimulation of a TCE-contaminated Deep Fracture Basalt Aquifer

    SciTech Connect

    T. Wood; D. E. Cummings

    2004-12-01

    Sodium lactate additions to a trichloroethene (TCE) residual source area in deep, fractured basalt at a U.S. Department of Energy site have resulted in the enrichment of the indigenous microbial community, the complete dechlorination of nearly all aqueous-phase TCE to ethene, and the continued depletion of the residual source since 1999. The bacterial and archaeal consortia in groundwater obtained from the residual source were assessed by using PCR-amplified 16S rRNA genes. A clone library of bacterial amplicons was predominated by those from members of the class Clostridia (57 of 93 clones), of which a phylotype most similar to that of the homoacetogen Acetobacterium sp. strain HAAP-1 was most abundant (32 of 93 clones). The remaining Bacteria consisted of phylotypes affiliated with Sphingobacteria, Bacteroides, Spirochaetes, Mollicutes, and Proteobacteria and candidate divisions OP11 and OP3. The two proteobacterial phylotypes were most similar to those of the known dechlorinators Trichlorobacter thiogenes and Sulfurospirillum multivorans. Although not represented by the bacterial clones generated with broad-specificity bacterial primers, a Dehalococcoides-like phylotype was identified with genus-specific primers. Only four distinct phylotypes were detected in the groundwater archaeal library, including predominantly a clone affiliated with the strictly acetoclastic methanogen Methanosaeta concilii (24 of 43 clones). A mixed culture that completely dechlorinates TCE to ethene was enriched from this groundwater, and both communities were characterized by terminal restriction fragment length polymorphism (T-RFLP). According to T-RFLP, the laboratory enrichment community was less diverse overall than the groundwater community, with 22 unique phylotypes as opposed to 43 and a higher percentage of Clostridia, including the Acetobacterium population. Bioreactor archaeal structure was very similar to that of the groundwater community, suggesting that methane is

  17. Comparison Of A Laboratory Consortium That Dechlorinates TCE To Ethene To The Field Community From Which It Was Derived

    SciTech Connect

    T. Wood; K. S. Sorenson; D. E. Cummings

    2004-12-01

    Sodium lactate additions to a trichloroethene (TCE) residual source area in deep, fractured basalt at a U.S. Department of Energy site have resulted in the enrichment of the indigenous microbial community, the complete dechlorination of nearly all aqueous-phase TCE to ethene, and the continued depletion of the residual source since 1999. The bacterial and archaeal consortia in groundwater obtained from the residual source were assessed by using PCR-amplified 16S rRNA genes. A clone library of bacterial amplicons was predominated by those from members of the class Clostridia (57 of 93 clones), of which a phylotype most similar to that of the homoacetogen Acetobacterium sp. strain HAAP-1 was most abundant (32 of 93 clones). The remaining Bacteria consisted of phylotypes affiliated with Sphingobacteria, Bacteroides, Spirochaetes, Mollicutes, and Proteobacteria and candidate divisions OP11 and OP3. The two proteobacterial phylotypes were most similar to those of the known dechlorinators Trichlorobacter thiogenes and Sulfurospirillum multivorans. Although not represented by the bacterial clones generated with broad-specificity bacterial primers, a Dehalococcoides-like phylotype was identified with genus-specific primers. Only four distinct phylotypes were detected in the groundwater archaeal library, including predominantly a clone affiliated with the strictly acetoclastic methanogen Methanosaeta concilii (24 of 43 clones). A mixed culture that completely dechlorinates TCE to ethene was enriched from this groundwater, and both communities were characterized by terminal restriction fragment length polymorphism (T-RFLP). According to T-RFLP, the laboratory enrichment community was less diverse overall than the groundwater community, with 22 unique phylotypes as opposed to 43 and a higher percentage of Clostridia, including the Acetobacterium population. Bioreactor archaeal structure was very similar to that of the groundwater community, suggesting that methane is

  18. Nitric oxide reduces flow-induced superoxide production via cGMP-dependent protein kinase in thick ascending limbs

    PubMed Central

    Hong, Nancy J.; Garvin, Jeffrey L.

    2009-01-01

    We have shown that increased luminal flow induces O2− and nitric oxide (NO) production in thick ascending limbs (TALs). However, the interaction of flow-stimulated NO and O2− in TALs is unclear. We hypothesized that NO inhibits flow-induced O2− production in TALs via cGMP-dependent protein kinase (PKG). We measured flow-stimulated O2− production in rat TALs using dihydroethidium in the absence and presence of l-arginine (0.3 mM), the substrate for NO synthase. The addition of l-arginine reduced flow-induced net O2− production from 68 ± 9 to 17 ± 4 AU/s (P < 0.002). The addition of the NO synthase inhibitor NG-nitro-l-arginine methyl ester (l-NAME; 5 mM) in the presence of l-arginine stimulated production (l-arginine: 15 ± 4 AU/s vs. l-arginine + l-NAME: 63 ± 7 AU/s; P < 0.002). The guanylate cyclase inhibitor LY-83583 (10 μM) also enhanced flow-induced net O2− production in the presence of l-arginine (l-arginine: 7 ± 4 AU/s vs. l-arginine + LY-83583: 53 ± 7 AU/s; P < 0.01). In the presence of LY-83583, l-arginine only reduced flow-induced net O2− by 36% (LY-83583: 80 ± 7 AU/s vs. LY-83583 + l-arginine: 51 ± 3 AU/s; P < 0.006). The cGMP analog dibutyryl (db)-cGMP reduced flow-induced net O2− from 39 ± 9 to 7 ± 3 AU/s (P < 0.03). The PKG inhibitor KT-5823 (5 μM) partially restored flow-induced net O2− in the presence of l-arginine (l-arginine: 4 ± 4 AU/s vs. l-arginine + KT-5823: 32 ± 9 AU/s; P < 0.03) and db-cGMP (db-cGMP: 9 ± 7 AU/s vs. db-cGMP + KT-5823: 54 ± 5 AU/s; P < 0.01). Phosphodiesterase II inhibition had no effect on arginine-inhibited O2− production. We conclude that 1) NO reduces flow-stimulated O2− production, 2) this occurs primarily via the cGMP/PKG pathway, and 3) O2− scavenging by NO plays a minor role. PMID:19244401

  19. Aromen

    NASA Astrophysics Data System (ADS)

    Salzer, Uwe-Jens; Krammer, Gerhard

    Aromen sind Zubereitungen/Mischungen aus Aromastoffen und/oder Aromaextrakten. Weiterhin gibt es Rauch- und Reaktionsaromen. Alle Einzelbestandteile können auch als Aroma bezeichnet werden, z. B. der Aromastoff Vanillin.

  20. Cloning and functional expression in E. coli of a polyphenol oxidase transcript from Coreopsis grandiflora involved in aurone formation☆

    PubMed Central

    Kaintz, Cornelia; Molitor, Christian; Thill, Jana; Kampatsikas, Ioannis; Michael, Claudia; Halbwirth, Heidi; Rompel, Annette

    2014-01-01

    Polyphenol oxidases are involved in aurone biosynthesis but the gene responsible for 4-deoxyaurone formation in Asteraceae was so far unknown. Three novel full-length cDNA sequences were isolated from Coreopsis grandiflora with sizes of 1.80 kb (cgAUS1) and 1.85 kb (cgAUS2a, 2b), encoding for proteins of 68–69 kDa, respectively. cgAUS1 is preferably expressed in young petals indicating a specific role in pigment formation. The 58.9 kDa AUS1 holoproenzyme, was recombinantly expressed in E. coli and purified to homogeneity. The enzyme shows only diphenolase activity, catalyzing the conversion of chalcones to aurones and was characterized by SDS–PAGE and shot-gun type nanoUHPLC–ESI-MS/MS. PMID:25109778

  1. 77 FR 5291 - The Designation of Monir Chouka, also Known as Mounir Chouka, Also Known as Abu Adam, Also Known...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-02

    ... Germany, also Known as Abu Adam aus Deutschland, as a Specially Designated Global Terrorist Pursuant to... Monir Chouka, also known as Mounir Chouka, also known as Abu Adam from Germany, also known as Abu...

  2. Increased EMRSA-15 health-care worker colonization demonstrated in retrospective review of EMRSA hospital outbreaks

    PubMed Central

    2014-01-01

    Background Health care worker (HCW) colonization with methicillin resistant Staphylococcus aureus (MRSA) is a documented cause of hospital outbreaks and contributes to ongoing transmission. At Royal Perth Hospital (RPH) it had been anecdotally noted that the increasing prevalence of EMRSA-15 appeared to be associated with increased HCW colonization compared with Aus2/3-EMRSA. Hence we compared HCW colonization rates during outbreaks of EMRSA-15 and Aus2/3-EMRSA at a single institution. Methods We performed a retrospective review of EMRSA-15 and Aus2/3-EMRSA outbreaks from 2000–2009 at RPH, a quaternary hospital in Western Australia. Outbreak files were reviewed and relevant data extracted. Results Ten EMRSA-15 outbreaks were compared with seven Aus2/3 outbreaks. The number of patients colonized was similar between EMRSA-15 and Aus2/3-EMRSA outbreaks (median 7 [range 3–20] and 11 [5–26], respectively; P = 0.07) but the number of HCWs colonized was significantly higher in EMRSA-15 outbreaks compared to Aus2/3-EMRSA outbreaks (median 4 [range 0–15] and 2 [1-3], respectively; P = 0.013). The percentage of HCWs colonized was also higher in EMRSA-15 outbreaks versus Aus2/3-EMRSA outbreaks (median 3.4% [range 0–5.5%] and 0.81% [0.56–2.2%], respectively; P = 0.013). Conclusions This study demonstrates a higher level of HCW colonization during EMRSA-15 outbreaks compared with Aus2/3-EMRSA outbreaks. This finding suggests that MRSA vary in their ability to colonize HCWs and contribute to outbreaks. MRSA type should be determined during outbreaks and future research should investigate the mechanisms by which EMRSA-15 contributes to increased HCW colonization. PMID:24588849

  3. Photovoltaik Hybrid-Solarzellen mit Nanopartikeln

    NASA Astrophysics Data System (ADS)

    Leute, Angelika

    2004-09-01

    Die organische Photovoltaik auf der Basis halbleitender Polymere bietet eine kostengünstige Alternative zu Solarzellen aus Silizium. Allerdings weisen die organischen Materialien relativ schlechte Ladungstransporteigenschaften auf. Hybrid-Solarzellen, in denen Polymere mit geeigneten anorganischen Halbleitern kombiniert sind, besitzen einerseits die praktischen Vorteile der Organik und andererseits die hohe Elektronenbeweglichkeit der anorganischen Materialien. Wissenschaftler der Technischen Universität Eindhoven haben kürzlich Hybrid-Solarzellen vorgestellt, die aus einem halbleitenden Polymer mit Zinkoxid-Nanopartikeln bestehen.

  4. Survey of cytopathologists and cytotechnologists for the clinical impact of the use of atypia or follicular lesion of undetermined significance

    PubMed Central

    Nassar, Aziza; Reynolds, Jordan P.; Kerr, Sarah E.; Jenkins, Sarah M.; Lackore, Kandace A.; Bernet, Victor

    2015-01-01

    Background: The cytologic diagnosis of atypia of undetermined significance or follicular lesion of undetermined significance (AUS/FLUS) is controversial because of variation in how it is applied in practice, as well as uncertainty about patient management. We aimed to assess the percentage of thyroid fine-needle aspiration biopsies (FNABs) with AUS/FLUS diagnoses in different North American and European practice settings (e.g. community, academic, etc.), assess whether patients were managed according to current guidelines, and determine patient outcomes. Materials and Methods: A detailed questionnaire survey was posted in secure websites used separately by cytopathologists and cytotechnologists. The questionnaire was posted from August 1 through December 31, 2013. Results: Endocrinologists and cytopathologists performed 51.7% and 37.1% of thyroid FNABs, respectively. The Bethesda reporting system for thyroid FNAB was used in 90% of practices. The rate of AUS/FLUS varied widely among institutions, with 46.1% of represented institutions reporting AUS/FLUS rates of 3–10%. The median follow-up rate of patients with an initial AUS/FLUS diagnosis was 70% (range, 10–100%). For the majority of represented institutions (86.4%), patients with initial AUS/FLUS diagnosis had follow-up with endocrinologists. Of repeat AUS/FLUS thyroid FNABs, a median of 52% was considered benign, and 18% were suspicious of or positive for malignancy (median, 10% and 7.5%, respectively). Conclusions: Reporting of the AUS/FLUS category varied widely among different institutions. The median follow-up rate was lower than published guidelines. The most common follow-up diagnosis was benign thyroid nodule. Improved standardization of cytologic criteria should be adopted to reduce such variation. PMID:26195986

  5. Was wissen wir über Information?

    NASA Astrophysics Data System (ADS)

    Engelmann, Florian; Großmann, Christoph

    Der Begriff Information stammt aus dem Lateinischen. Von der Antike bis in das 20. Jahrhundert war Information ein kaum verwendetes und unspektakuläres Wort. ZEMANEK belegt diese Hypothese mit dem Verweis auf ein Häufigkeitswörterbuch der deutschen Sprache aus dem Jahre 1897. Dort kommt in ca. 11 Millionen Wörten nur 55 mal das Wort Information vor [Zemanek 1986, S. 19].

  6. Evaluation of Abdominal Ultrasonography Mass Screening for Hepatocellular Carcinoma in Taiwan

    PubMed Central

    Yeh, Yen-Po; Hu, Tsung-Hui; Cho, Po-Yuan; Chen, Hsiu-Hsi; Yen, Amy Ming-Fang; Chen, Sam Li-Sheng; Chiu, Sherry Yueh-Hsia; Fann, Jean Ching-Yuan; Su, Wei-Wen; Fang, Yi-Jen; Chen, Shih-Tien; San, Hsiao-Ching; Chen, Hung-Pin; Liao, Chao-Sheng

    2014-01-01

    Mass screening with abdominal ultrasonography (AUS) has been suggested as a tool to control adult hepatocellular carcinoma (HCC) in individuals, but its efficacy in reducing HCC mortality has never been demonstrated. This study aimed to assess the effectiveness of reducing HCC mortality by mass AUS screening for HCC based on a program designed and implemented in the Changhua Community-based Integrated Screening (CHCIS) program with an efficient invitation scheme guided by the risk score. We invited 11,114 (27.0%) of 41,219 eligible Taiwanese subjects between 45 and 69 years of age who resided in an HCC high-incidence area to attend a risk score-guided mass AUS screening between 2008 and 2010. The efficacy of reducing HCC mortality was estimated. Of the 8,962 AUS screening attendees (with an 80.6% attendance rate), a total of 16 confirmed HCC cases were identified through community-based ultrasonography screening. Among the 16 screen-detected HCC cases, only two died from HCC, indicating a favorable survival. The cumulative mortality due to HCC (per 100,000) was considerably lower in the invited AUS group (17.26) compared with the uninvited AUS group (42.87) and the historical control group (47.51), yielding age- and gender-adjusted relative mortality rates of 0.69 (95% confidence interval [CI]: 0.56-0.84) and 0.63 (95% CI: 0.52-0.77), respectively. Conclusion: The residents invited to community-based AUS screening for HCC, compared with those who were not invited, showed a reduction in HCC mortality by ∼31% among subjects aged 45-69 years who had not been included in the nationwide vaccination program against hepatitis B virus infection. (Hepatology 2014;59:1840–1849) PMID:24002724

  7. Anisotropic chemical pressure effects in single-component molecular metals based on radical dithiolene and diselenolene gold complexes.

    PubMed

    Yzambart, Gilles; Bellec, Nathalie; Nasser, Ghassan; Jeannin, Olivier; Roisnel, Thierry; Fourmigué, Marc; Auban-Senzier, Pascale; Íñiguez, Jorge; Canadell, Enric; Lorcy, Dominique

    2012-10-17

    On the basis of the reported radical neutral complex [Au(Et-thiazdt)(2)] (Et-thiazdt = N-ethyl-1,3-thiazoline-2-thione-4,5-dithiolate), a series of single-component conductors derived from [Au(Et-thiazdt)(2)], also noted as [AuS(4)(═S)(2)], has been developed, by replacing the outer sulfur atoms of the thiazoline-2-thione rings by oxygen atoms and/or by replacing the coordinating sulfur atoms by selenium atoms toward the corresponding diselenolene complexes. Comparison of the X-ray crystal structures and transport properties of the four isostructural complexes, noted as [AuS(4)(═S)(2)], [AuS(4)(═O)(2)], [AuSe(4)(═S)(2)], and [AuSe(4)(═O)(2)], shows that the oxygen substitution on the outer thiazoline ring actually decreases the conductivity by a factor of 100, despite a contracted unit cell volume reflecting a positive chemical pressure effect. On the other hand, the S/Se substitution increases the conductivity by a factor of 100, and the pressure needed to transform these semiconductors into the metallic state is shifted from 13 kbar in [AuS(4)(═S)(2)] to only ≈6 kbar in [AuSe(4)(═S)(2)]. Analysis of unit cell evolutions and ab initio band structure calculations demonstrates the strongly anisotropic nature of this chemical pressure effect and provides an explanation for the observed changes in conductivity. The greater sensitivity of these neutral single-component conductors to external pressure, as compared with "classical" radical salts, is also highlighted. PMID:23009033

  8. Usefulness of NRAS codon 61 mutation analysis and core needle biopsy for the diagnosis of thyroid nodules previously diagnosed as atypia of undetermined significance.

    PubMed

    Jang, Eun Kyung; Kim, Won Gu; Kim, Eui Young; Kwon, Hyemi; Choi, Yun Mi; Jeon, Min Ji; Baek, Jung Hwan; Lee, Jeong Hyun; Kim, Tae Yong; Shong, Young Kee; Choi, Jene; Song, Dong Eun; Kim, Won Bae

    2016-05-01

    A repeat fine needle aspiration (FNA) is recommended for thyroid nodules diagnosed as atypia of undetermined significance (AUS) in a previous cytology. We evaluated the utility of NRAS codon 61 (NRAS61) mutation analysis and core needle biopsy (CNB) for the diagnosis of thyroid nodules previously diagnosed as AUS. This study enrolled 236 patients who underwent both NRAS61 mutation analysis and CNB of thyroid nodules previously diagnosed as AUS at cytology. The NRAS61 mutation was detected in 36 nodules and was more frequently detected in the AUS and follicular neoplasm (FN)/suspicious for follicular neoplasm (SFN) categories, as determined by histological analysis of CNB, than in the benign group (p = 0.005). Sixty-one patients underwent surgery, and 29 nodules were finally diagnosed as malignant after surgery. Among 61 patients who underwent surgery, nodules with the NRAS61 mutation (42-65 %) had a significantly higher malignancy rate than nodules with wild-type NRAS61 (7-37 %, p = 0.038). The association between malignancy and the NRAS61 mutation was significant after adjusting for age, sex, nodule size, and histological diagnosis of CNB (p = 0.01). NRAS61 mutation analysis together with CNB could be helpful for arriving at a clinical decision in patients with thyroid nodules showing AUS in a previous cytology. PMID:26547216

  9. The Bethesda system for reporting thyroid cytopathology: An experience of 1,382 cases in a community practice setting with the implication for risk of neoplasm and risk of malignancy.

    PubMed

    Wu, Howard Her-Juing; Rose, Crystal; Elsheikh, Tarik M

    2012-05-01

    The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) has provided a set of uniform diagnostic terminology including benign (B), atypia of undetermined significance (AUS), follicular neoplasm (FN), suspicious for malignancy (SM), malignancy (M), and nondiagnostic (ND) for the interpretation of thyroid fine-needle aspiration (FNA). We applied this terminology on our 1,382 thyroid aspirates in a community practice setting, which included 539 cases of B (39%), 376 cases of AUS (27.2%), 116 cases of FN (8.4%), 37 cases of malignant (2.7%), 36 cases of SM (2.6%), and 278 cases of ND (20.1%). Two hundred twenty-one cases (16%) of thyroid FNA had corresponding follow-up thyroidectomies. Each diagnostic category represented a unique association with risk of malignancy and risk of neoplasm. Based on histologic follow-up, the risk of neoplasm (including benign and malignant neoplasm) was B 14%, AUS 44%, FN 67%, SM 77%, and M 100% and the risk of malignancy was B 3%, AUS 6%, FN 22%, SM 56%, and M 100%. The classification and follow-up recommendation of TBSRTC are appropriate for each category. Both B and AUS are low-risk lesions with low probability of malignancy. FN predicts a higher rate for neoplasm but an intermediate rate for malignancy while SM carries a high risk for malignancy. PMID:21681976

  10. Alcohol Use Severity among Hispanic Emerging Adults in Higher Education: Understanding the Effect of Cultural Congruity

    PubMed Central

    Cano, Miguel Ángel; Vaughan, Ellen L.; de Dios, Marcel A.; Castro, Yessenia; Roncancio, Angelica M.; Ojeda, Lizette

    2016-01-01

    Background Identifying and understanding determinants of alcohol use behavior among Hispanic college students is an increasingly important public health issue, particularly during emerging adulthood. Studies examining ethnocultural determinants of alcohol use behavior among Hispanic college students have focused on direct associations with cultural orientation (e.g., acculturation and enculturation); yet there is a need for research that accounts for the complex interplay of other culturally relevant sociocultural factors. Objectives This study examined associations of behavioral acculturation, behavioral enculturation, and cultural congruity (perception of cultural fit between the values of the academic environment and the student's personal values) with alcohol use severity (AUS); and tested if gender moderated those associations. Methods A hierarchical linear regression and moderation analysis were conducted on a sample of 167 Hispanic emerging adults (ages 18 to 25) enrolled in college. Results All predictor variables entered in the regression model accounted for 20.9% of the variance in AUS. After controlling for demographic variables and depressive symptoms, behavioral acculturation and enculturation did not have a statistically significant association with AUS. Further, gender did not moderate either of these associations. Conversely, greater cultural congruity was associated with lower reports of AUS. A moderation analysis suggested that cultural congruity predicted lower reports of AUS among men, but not among women. Conclusions This was the first known study to examine the association of cultural congruity with alcohol use. Findings highlight the value of examining contextual factors of culture and moving beyond reductive measures of cultural orientation. PMID:26574656

  11. The Current Role of the Artificial Urinary Sphincter in Male and Female Urinary Incontinence

    PubMed Central

    Islah, MAR; Cho, Sung Yong

    2013-01-01

    The evolution of the artificial urinary sphincter has affected the current surgical options for urinary incontinence. With its unique features, the artificial urinary sphincter (AUS) has been an attractive option for the treatment of urinary incontinence regardless of gender. The current paper discusses the indications, contraindications, types of devices, surgical approaches, outcomes, and complications of the AUS in the treatment of both male and female urinary incontinence. A PubMed review of the available literature was performed and articles reporting implantation of artificial urinary sphincters for urinary incontinence in both male and female patients were evaluated. There was a comparable satisfactory continence rate after the implantation of an AUS (59~97% in males vs. 60~92% in females). In comparison, there were some differences in the indications, contraindications, surgical approaches, outcomes, and complications of the AUS implanted for urinary incontinence in male and female patients. AUS implantation is a safe and effective surgical option for the treatment of urinary incontinence of various etiologies. Continuous evolution of the device has made it an attractive option for the treatment of both male and female urinary incontinence. PMID:23658862

  12. Methodik und Qualität statistischer Erhebungen

    NASA Astrophysics Data System (ADS)

    Krug, Walter; Schmidt, Jürgen; Wiegert, Rolf

    Kapitel 8 wirft einen Blick hinter die Kulissen statistischer Arbeit und ihrer Methoden, insbesondere auch hinter die der amtlichen Statistik: Wie kommen die Myriaden von Zahlen zustande, die heute aus statistischen Quellenwerken aller Art und aus Datenbanken abgerufen werden können? Dabei wird deutlich, welche Schwierigkeiten bei Erhebungen, insbesondere bei Stichprobenerhebungen, zu überwinden sind, wie man Antwortverweigerer kooperativer stimmt, wie sich auch aus kleinen Stichproben auf intelligente Weise verlässliche Ergebnisse erzielen lassen und wie Großstichproben auf europäischer Ebene harmonisiert werden. Am Beispiel des Zensus 2011 wird gezeigt, wie sich eine Kombination von Stichproben und Registerauswertungen als Ersatz für eine Volkszählung nutzen lässt. Mitglieder der Deutschen Statistischen Gesellschaft waren daran kooperativ beteiligt.

  13. Wie entsteht Bewusstsein?: Einfache Modelle der Selbstwahrnehmung

    NASA Astrophysics Data System (ADS)

    Schuster, Heinz Georg

    2003-07-01

    Was ist die funktionale Basis der Entstehung des Bewusstseins? Warum bringt dieses in der Evolution einen Vorteil? Diese Fragen werden anhand von drei Spielen untersucht, in denen die Spieler mathematisch modelliert sind. Im ersten Spiel lernt ein Spieler, seine Stellung in einer Hierarchie aus der Interaktion mit anderen zu erraten. Im zweiten Spiel macht ein Zuwachs des Gedächtnisses einen Spieler zum Gewinner: Das ermöglicht ihm einen Spiel entscheidenden Überblick über sein eigenes Verhalten und das seines Gegners. Im dritten Spiel müssen die Spieler die Farbe des Hutes auf dem eigenen Kopf aus der Reaktion des Gegners erraten. Hier ist die Fähigkeit von Vorteil, Inhalte aus dem Langzeit- und Kurzzeitgedächtnis im Geist abbilden und manipulieren zu können.

  14. Speaker and Accent Variation Are Handled Differently: Evidence in Native and Non-Native Listeners.

    PubMed

    Kriengwatana, Buddhamas; Terry, Josephine; Chládková, Kateřina; Escudero, Paola

    2016-01-01

    Listeners are able to cope with between-speaker variability in speech that stems from anatomical sources (i.e. individual and sex differences in vocal tract size) and sociolinguistic sources (i.e. accents). We hypothesized that listeners adapt to these two types of variation differently because prior work indicates that adapting to speaker/sex variability may occur pre-lexically while adapting to accent variability may require learning from attention to explicit cues (i.e. feedback). In Experiment 1, we tested our hypothesis by training native Dutch listeners and Australian-English (AusE) listeners without any experience with Dutch or Flemish to discriminate between the Dutch vowels /I/ and /ε/ from a single speaker. We then tested their ability to classify /I/ and /ε/ vowels of a novel Dutch speaker (i.e. speaker or sex change only), or vowels of a novel Flemish speaker (i.e. speaker or sex change plus accent change). We found that both Dutch and AusE listeners could successfully categorize vowels if the change involved a speaker/sex change, but not if the change involved an accent change. When AusE listeners were given feedback on their categorization responses to the novel speaker in Experiment 2, they were able to successfully categorize vowels involving an accent change. These results suggest that adapting to accents may be a two-step process, whereby the first step involves adapting to speaker differences at a pre-lexical level, and the second step involves adapting to accent differences at a contextual level, where listeners have access to word meaning or are given feedback that allows them to appropriately adjust their perceptual category boundaries. PMID:27309889

  15. Characterisation of a new stripe rust resistance gene Yr47 and its genetic association with the leaf rust resistance gene Lr52.

    PubMed

    Bansal, U K; Forrest, K L; Hayden, M J; Miah, H; Singh, D; Bariana, H S

    2011-05-01

    Two Iranian common wheat landraces AUS28183 and AUS28187 from the Watkins collection showed high levels of seedling resistance against Australian pathotypes of leaf rust and stripe rust pathogens. Chi-squared analyses of rust response segregation among F(3) populations derived from crosses of AUS28183 and AUS28187 with a susceptible genotype AUS27229 revealed monogenic inheritance of leaf rust and stripe rust resistance. As both genotypes produced similar leaf rust and stripe rust infection types, they were assumed to carry the same genes. The genes were temporarily named as LrW1 and YrW1. Molecular mapping placed LrW1 and YrW1 in the short arm of chromosome 5B, about 10 and 15 cM proximal to the SSR marker gwm234, respectively, and the marker cfb309 mapped 8-12 cM proximal to YrW1. LrW1 mapped 3-6 cM distal to YrW1 in two F(3) populations. AUS28183 corresponded to the accession V336 of the Watkins collection which was the original source of Lr52. Based on the genomic location and accession records, LrW1 was concluded to be Lr52. Because no other seedling stripe rust resistance gene has previously been mapped in chromosome 5BS, YrW1 was permanently named as Yr47. A combination of flanking markers gwm234 and cfb309 with phenotypic assays could be used to ascertain the presence of Lr52 and Yr47 in segregating populations. This investigation characterised a valuable source of dual leaf rust and stripe rust resistance for deployment in new wheat cultivars. Transfer of Lr52 and Yr47 into current Australian wheat backgrounds is in progress. PMID:21344185

  16. Speaker and Accent Variation Are Handled Differently: Evidence in Native and Non-Native Listeners

    PubMed Central

    Kriengwatana, Buddhamas; Terry, Josephine; Chládková, Kateřina; Escudero, Paola

    2016-01-01

    Listeners are able to cope with between-speaker variability in speech that stems from anatomical sources (i.e. individual and sex differences in vocal tract size) and sociolinguistic sources (i.e. accents). We hypothesized that listeners adapt to these two types of variation differently because prior work indicates that adapting to speaker/sex variability may occur pre-lexically while adapting to accent variability may require learning from attention to explicit cues (i.e. feedback). In Experiment 1, we tested our hypothesis by training native Dutch listeners and Australian-English (AusE) listeners without any experience with Dutch or Flemish to discriminate between the Dutch vowels /I/ and /ε/ from a single speaker. We then tested their ability to classify /I/ and /ε/ vowels of a novel Dutch speaker (i.e. speaker or sex change only), or vowels of a novel Flemish speaker (i.e. speaker or sex change plus accent change). We found that both Dutch and AusE listeners could successfully categorize vowels if the change involved a speaker/sex change, but not if the change involved an accent change. When AusE listeners were given feedback on their categorization responses to the novel speaker in Experiment 2, they were able to successfully categorize vowels involving an accent change. These results suggest that adapting to accents may be a two-step process, whereby the first step involves adapting to speaker differences at a pre-lexical level, and the second step involves adapting to accent differences at a contextual level, where listeners have access to word meaning or are given feedback that allows them to appropriately adjust their perceptual category boundaries. PMID:27309889

  17. Aiding the environment: the Australian Development Agency's experience of implementing an environmental management system

    SciTech Connect

    Keen, Meg . E-mail: meg.keen@anu.edu.au; Sullivan, Marjorie

    2005-08-15

    Aid agencies, like commercial businesses, are increasingly concerned with incorporating sound environmental management into their operations. Different approaches are being used to integrate sustainability into development assistance to ensure that environmental impacts are assessed and managed. One approach being used by AusAID, the Australian aid agency, is to implement an environmental management system (EMS) across program and project areas. This paper examines how AusAID has adapted the EMS approach to suit aid agency operations, and some of the lessons from the Australian experience.

  18. Einführung in moderne analytische Verfahren mit ausgewählten Beispielen

    NASA Astrophysics Data System (ADS)

    Stadler, Richard; Gude, Thomas

    Die Lebensmittelanalytik hat während der letzten zehn bis fünfzehn Jahre in den meisten Bereichen fundamentale und fast "exponentielle" Fortschritte erzielt. Es gibt viele unterschiedliche, aber zusammenhängende Gründe für diese rasche Entwicklung. Deutliche Impulse kommen aus dem zunehmenden Aufwand für Qualitätssicherungsmaßnahmen, die aus Kosten- bzw. Wirtschaftlichkeitsgründen möglichst einfach und leicht durchzuführende Tests fordern.

  19. High-resolution structure and mechanism of an F/V-hybrid rotor ring in a Na+-coupled ATP synthase

    NASA Astrophysics Data System (ADS)

    Matthies, Doreen; Zhou, Wenchang; Klyszejko, Adriana L.; Anselmi, Claudio; Yildiz, Özkan; Brandt, Karsten; Müller, Volker; Faraldo-Gómez, José D.; Meier, Thomas

    2014-11-01

    All rotary ATPases catalyse the interconversion of ATP and ADP-Pi through a mechanism that is coupled to the transmembrane flow of H+ or Na+. Physiologically, however, F/A-type enzymes specialize in ATP synthesis driven by downhill ion diffusion, while eukaryotic V-type ATPases function as ion pumps. To begin to rationalize the molecular basis for this functional differentiation, we solved the crystal structure of the Na+-driven membrane rotor of the Acetobacterium woodii ATP synthase, at 2.1 Å resolution. Unlike known structures, this rotor ring is a 9:1 heteromer of F- and V-type c-subunits and therefore features a hybrid configuration of ion-binding sites along its circumference. Molecular and kinetic simulations are used to dissect the mechanisms of Na+ recognition and rotation of this c-ring, and to explain the functional implications of the V-type c-subunit. These structural and mechanistic insights indicate an evolutionary path between synthases and pumps involving adaptations in the rotor ring.

  20. Carbon Isotope Fractionation of 11 Acetogenic Strains Grown on H2 and CO2

    PubMed Central

    Dreisbach, Lisa K.; Conrad, Ralf

    2013-01-01

    Acetogenic bacteria are able to grow autotrophically on hydrogen and carbon dioxide by using the acetyl coenzyme A (acetyl-CoA) pathway. Acetate is the end product of this reaction. In contrast to the fermentative route of acetate production, which shows almost no fractionation of carbon isotopes, the acetyl-CoA pathway has been reported to exhibit a preference for light carbon. In Acetobacterium woodii the isotope fractionation factor (ε) for 13C and 12C has previously been reported to be ε = −58.6‰. To investigate whether such a strong fractionation is a general feature of acetogenic bacteria, we measured the stable carbon isotope fractionation factor of 10 acetogenic strains grown on H2 and CO2. The average fractionation factor was εTIC = −57.2‰ for utilization of total inorganic carbon and εacetate = −54.6‰ for the production of acetate. The strongest fractionation was found for Sporomusa sphaeroides (εTIC = −68.3‰), the lowest fractionation for Morella thermoacetica (εTIC = −38.2‰). To investigate the reproducibility of our measurements, we determined the fractionation factor of 21 biological replicates of Thermoanaerobacter kivui. In general, our study confirmed the strong fractionation of stable carbon during chemolithotrophic acetate formation in acetogenic bacteria. However, the specific characteristics of the bacterial strain, as well as the cultural conditions, may have a moderate influence on the overall fractionation. PMID:23275504

  1. Energetics and Application of Heterotrophy in Acetogenic Bacteria.

    PubMed

    Schuchmann, Kai; Müller, Volker

    2016-07-15

    Acetogenic bacteria are a diverse group of strictly anaerobic bacteria that utilize the Wood-Ljungdahl pathway for CO2 fixation and energy conservation. These microorganisms play an important part in the global carbon cycle and are a key component of the anaerobic food web. Their most prominent metabolic feature is autotrophic growth with molecular hydrogen and carbon dioxide as the substrates. However, most members also show an outstanding metabolic flexibility for utilizing a vast variety of different substrates. In contrast to autotrophic growth, which is hardly competitive, metabolic flexibility is seen as a key ability of acetogens to compete in ecosystems and might explain the almost-ubiquitous distribution of acetogenic bacteria in anoxic environments. This review covers the latest findings with respect to the heterotrophic metabolism of acetogenic bacteria, including utilization of carbohydrates, lactate, and different alcohols, especially in the model acetogen Acetobacterium woodii Modularity of metabolism, a key concept of pathway design in synthetic biology, together with electron bifurcation, to overcome energetic barriers, appears to be the basis for the amazing substrate spectrum. At the same time, acetogens depend on only a relatively small number of enzymes to expand the substrate spectrum. We will discuss the energetic advantages of coupling CO2 reduction to fermentations that exploit otherwise-inaccessible substrates and the ecological advantages, as well as the biotechnological applications of the heterotrophic metabolism of acetogens. PMID:27208103

  2. Fermentative degradation of polyethylene glycol by a strictly anaerobic, gram-negative, nonsporeforming bacterium, Pelobacter venetianus sp. nov.

    PubMed Central

    Schink, B; Stieb, M

    1983-01-01

    The synthetic polyether polyethylene glycol (PEG) with a molecular weight of 20,000 was anaerobically degraded in enrichment cultures inoculated with mud of limnic and marine origins. Three strains (Gra PEG 1, Gra PEG 2, and Ko PEG 2) of rod-shaped, gram-negative, nonsporeforming, strictly anaerobic bacteria were isolated in mineral medium with PEG as the sole source of carbon and energy. All strains degraded dimers, oligomers, and polymers of PEG up to a molecular weight of 20,000 completely by fermentation to nearly equal amounts of acetate and ethanol. The monomer ethylene glycol was not degraded. An ethylene glycol-fermenting anaerobe (strain Gra EG 12) isolated from the same enrichments was identified as Acetobacterium woodii. The PEG-fermenting strains did not excrete extracellular depolymerizing enzymes and were inhibited by ethylene glycol, probably owing to a blocking of the cellular uptake system. PEG, some PEG-containing nonionic detergents, 1,2-propanediol, 1,2-butanediol, glycerol, and acetoin were the only growth substrates utilized of a broad variety of sugars, organic acids, and alcohols. The isolates did not reduce sulfate, sulfur, thiosulfate, or nitrate and were independent of growth factors. In coculture with A. woodii or Methanospirillum hungatei, PEGs and ethanol were completely fermented to acetate (and methane). A marine isolate is described as the type strain of a new species, Pelobacter venetianus sp. nov. Its physiology and ecological significance, as well as the importance and possible mechanism of anaerobic polyether degradation, are discussed. Images PMID:6881964

  3. High-Resolution Structure and Mechanism of an F/V-Hybrid Rotor Ring in a Na+-coupled ATP Synthase

    PubMed Central

    Matthies, Doreen; Zhou, Wenchang; Klyszejko, Adriana L.; Anselmi, Claudio; Yildiz, Özkan; Brandt, Karsten; Müller, Volker; Faraldo-Gómez, José D.; Meier, Thomas

    2014-01-01

    All rotary ATPases catalyze the interconversion of ATP and ADP-Pi through a mechanism that is coupled to the transmembrane flow of H+ or Na+. Physiologically, however, F/A-type enzymes specialize in ATP synthesis driven by downhill ion diffusion, while eukaryotic V-type ATPases function as ion pumps. To begin to rationalize the molecular basis for this functional differentiation, we solved the crystal structure of the Na+-driven membrane rotor of the Acetobacterium woodii ATP synthase, at 2.1 Å resolution. Unlike known structures, this rotor ring is a 9:1 heteromer of F- and V-type c-subunits, and therefore features a hybrid configuration of ion-binding sites along its circumference. Molecular and kinetic simulations are used to dissect the mechanisms of Na+ recognition and rotation of this c-ring, and to explain the functional implications of the V-type c-subunit. These structural and mechanistic insights indicate an evolutionary path between synthases and pumps involving adaptations in the rotor ring. PMID:25381992

  4. Analysis of microbial communities in the oil reservoir subjected to CO2-flooding by using functional genes as molecular biomarkers for microbial CO2 sequestration

    PubMed Central

    Liu, Jin-Feng; Sun, Xiao-Bo; Yang, Guang-Chao; Mbadinga, Serge M.; Gu, Ji-Dong; Mu, Bo-Zhong

    2015-01-01

    Sequestration of CO2 in oil reservoirs is considered to be one of the feasible options for mitigating atmospheric CO2 building up and also for the in situ potential bioconversion of stored CO2 to methane. However, the information on these functional microbial communities and the impact of CO2 storage on them is hardly available. In this paper a comprehensive molecular survey was performed on microbial communities in production water samples from oil reservoirs experienced CO2-flooding by analysis of functional genes involved in the process, including cbbM, cbbL, fthfs, [FeFe]-hydrogenase, and mcrA. As a comparison, these functional genes in the production water samples from oil reservoir only experienced water-flooding in areas of the same oil bearing bed were also analyzed. It showed that these functional genes were all of rich diversity in these samples, and the functional microbial communities and their diversity were strongly affected by a long-term exposure to injected CO2. More interestingly, microorganisms affiliated with members of the genera Methanothemobacter, Acetobacterium, and Halothiobacillus as well as hydrogen producers in CO2 injected area either increased or remained unchanged in relative abundance compared to that in water-flooded area, which implied that these microorganisms could adapt to CO2 injection and, if so, demonstrated the potential for microbial fixation and conversion of CO2 into methane in subsurface oil reservoirs. PMID:25873911

  5. Influence of Acidic pH on Hydrogen and Acetate Production by an Electrosynthetic Microbiome

    PubMed Central

    LaBelle, Edward V.; Marshall, Christopher W.; Gilbert, Jack A.; May, Harold D.

    2014-01-01

    Production of hydrogen and organic compounds by an electrosynthetic microbiome using electrodes and carbon dioxide as sole electron donor and carbon source, respectively, was examined after exposure to acidic pH (∼5). Hydrogen production by biocathodes poised at −600 mV vs. SHE increased>100-fold and acetate production ceased at acidic pH, but ∼5–15 mM (catholyte volume)/day acetate and>1,000 mM/day hydrogen were attained at pH ∼6.5 following repeated exposure to acidic pH. Cyclic voltammetry revealed a 250 mV decrease in hydrogen overpotential and a maximum current density of 12.2 mA/cm2 at −765 mV (0.065 mA/cm2 sterile control at −800 mV) by the Acetobacterium-dominated community. Supplying −800 mV to the microbiome after repeated exposure to acidic pH resulted in up to 2.6 kg/m3/day hydrogen (≈2.6 gallons gasoline equivalent), 0.7 kg/m3/day formate, and 3.1 kg/m3/day acetate ( = 4.7 kg CO2 captured). PMID:25333313

  6. Quantitative Fluorescence In Situ Hybridization Analysis of Microbial Consortia from a Biogenic Gas Field in Alaska's Cook Inlet Basin

    PubMed Central

    Strąpoć, Dariusz; Huizinga, Brad; Lidstrom, Ulrika; Ashby, Matt; Macalady, Jennifer L.

    2012-01-01

    Filter-collected production water samples from a methane-rich gas field in the Cook Inlet basin of Alaska were investigated using whole-cell rRNA-targeted fluorescence in situ hybridization (FISH) and 16S rRNA tag pyrosequencing. Both techniques were consistent in determining the microbial community composition, including the archaeal or bacterial dominance of samples. The archaeal community is dominated by the obligate methylotrophic methanogen genus Methanolobus as well as the nutritional generalist methanogen genus Methanosarcina, which is capable of utilizing acetate, CO2, and methyl-bearing compounds. The most-abundant bacterial groups are Firmicutes, notably of the Acetobacterium genus, and Cytophaga-Flexibacter-Bacteroides species (CFBs) affiliated with the order Bacteroidales. We observed spatial variation among samples in both the percentage of members of Archaea compared to that of members of Bacteria and the dominant members of the bacterial community, differences which could not be explained with the available geochemical data. Based upon the microbial community composition and the isotopic signature of methane associated with the Cook Inlet basin site, we propose a simplified reaction network beginning with the breakdown of coal macromolecules, followed by fermentation and methylotrophic and acetoclastic methane production. PMID:22427501

  7. Electrosynthesis of Organic Compounds from Carbon Dioxide Is Catalyzed by a Diversity of Acetogenic Microorganisms

    SciTech Connect

    Nevin, KP; Hensley, SA; Franks, AE; Summers, ZM; Ou, JH; Woodard, TL; Snoeyenbos-West, OL; Lovley, DR

    2011-04-20

    Microbial electrosynthesis, a process in which microorganisms use electrons derived from electrodes to reduce carbon dioxide to multicarbon, extracellular organic compounds, is a potential strategy for capturing electrical energy in carbon-carbon bonds of readily stored and easily distributed products, such as transportation fuels. To date, only one organism, the acetogen Sporomusa ovata, has been shown to be capable of electrosynthesis. The purpose of this study was to determine if a wider range of microorganisms is capable of this process. Several other acetogenic bacteria, including two other Sporomusa species, Clostridium ljungdahlii, Clostridium aceticum, and Moorella thermoacetica, consumed current with the production of organic acids. In general acetate was the primary product, but 2-oxobutyrate and formate also were formed, with 2-oxobutyrate being the predominant identified product of electrosynthesis by C. aceticum. S. sphaeroides, C. ljungdahlii, and M. thermoacetica had high (> 80%) efficiencies of electrons consumed and recovered in identified products. The acetogen Acetobacterium woodii was unable to consume current. These results expand the known range of microorganisms capable of electrosynthesis, providing multiple options for the further optimization of this process.

  8. Spatial heterogeneity of dechlorinating bacteria and limiting factors for in situ trichloroethene dechlorination revealed by analyses of sediment cores from a polluted field site.

    PubMed

    Dowideit, Kerstin; Scholz-Muramatsu, Heidrun; Miethling-Graff, Rona; Vigelahn, Lothar; Freygang, Martina; Dohrmann, Anja B; Tebbe, Christoph C

    2010-03-01

    Microbiological analyses of sediment samples were conducted to explore potentials and limitations for bioremediation of field sites polluted with chlorinated ethenes. Intact sediment cores, collected by direct push probing from a 35-ha contaminated area, were analyzed in horizontal layers. Cultivation-independent PCR revealed Dehalococcoides to be the most abundant 16S rRNA gene phylotype with a suspected potential for reductive dechlorination of the major contaminant trichloroethene (TCE). In declining abundances, Desulfitobacterium, Desulfuromonas and Dehalobacter were also detected. In TCE-amended sediment slurry incubations, 66% of 121 sediment samples were dechlorinating, among them one-third completely and the rest incompletely (end product cis-1,2-dichloroethene; cDCE). Both PCR and slurry analyses revealed highly heterogeneous horizontal and vertical distributions of the dechlorination potentials in the sediments. Complete reductive TCE dechlorination correlated with the presence of Dehalococcoides, accompanied by Acetobacterium and a relative of Trichococcus pasteurii. Sediment incubations under close to in situ conditions showed that a low TCE dechlorination activity could be stimulated by 7 mg L(-1) dissolved carbon for cDCE formation and by an additional 36 mg carbon (lactate) L(-1) for further dechlorination. The study demonstrates that the highly heterogeneous distribution of TCE degraders and their specific requirements for carbon and electrons are key issues for TCE degradation in contaminated sites. PMID:20041951

  9. Clostridium ljungdahlii represents a microbial production platform based on syngas

    PubMed Central

    Köpke, Michael; Held, Claudia; Hujer, Sandra; Liesegang, Heiko; Wiezer, Arnim; Wollherr, Antje; Ehrenreich, Armin; Liebl, Wolfgang; Gottschalk, Gerhard; Dürre, Peter

    2010-01-01

    Clostridium ljungdahlii is an anaerobic homoacetogen, able to ferment sugars, other organic compounds, or CO2/H2 and synthesis gas (CO/H2). The latter feature makes it an interesting microbe for the biotech industry, as important bulk chemicals and proteins can be produced at the expense of CO2, thus combining industrial needs with sustained reduction of CO and CO2 in the atmosphere. Sequencing the complete genome of C. ljungdahlii revealed that it comprises 4,630,065 bp and is one of the largest clostridial genomes known to date. Experimental data and in silico comparisons revealed a third mode of anaerobic homoacetogenic metabolism. Unlike other organisms such as Moorella thermoacetica or Acetobacterium woodii, neither cytochromes nor sodium ions are involved in energy generation. Instead, an Rnf system is present, by which proton translocation can be performed. An electroporation procedure has been developed to transform the organism with plasmids bearing heterologous genes for butanol production. Successful expression of these genes could be demonstrated, leading to formation of the biofuel. Thus, C. ljungdahlii can be used as a unique microbial production platform based on synthesis gas and carbon dioxide/hydrogen mixtures. PMID:20616070

  10. The Complete Genome Sequence of Clostridium aceticum: a Missing Link between Rnf- and Cytochrome-Containing Autotrophic Acetogens

    PubMed Central

    Poehlein, Anja; Cebulla, Martin; Ilg, Marcus M.; Bengelsdorf, Frank R.; Schiel-Bengelsdorf, Bettina; Whited, Gregg; Andreesen, Jan R.; Gottschalk, Gerhard; Daniel, Rolf

    2015-01-01

    ABSTRACT Clostridium aceticum was the first isolated autotrophic acetogen, converting CO2 plus H2 or syngas to acetate. Its genome has now been completely sequenced and consists of a 4.2-Mbp chromosome and a small circular plasmid of 5.7 kbp. Sequence analysis revealed major differences from other autotrophic acetogens. C. aceticum contains an Rnf complex for energy conservation (via pumping protons or sodium ions). Such systems have also been found in C. ljungdahlii and Acetobacterium woodii. However, C. aceticum also contains a cytochrome, as does Moorella thermoacetica, which has been proposed to be involved in the generation of a proton gradient. Thus, C. aceticum seems to represent a link between Rnf- and cytochrome-containing autotrophic acetogens. In C. aceticum, however, the cytochrome is probably not involved in an electron transport chain that leads to proton translocation, as no genes for quinone biosynthesis are present in the genome. PMID:26350967

  11. Methanogenesis from Sucrose by Defined Immobilized Consortia

    PubMed Central

    Jones, W. Jack; Guyot, Jean-Pierre; Wolfe, Ralph S.

    1984-01-01

    A bacterial consortium capable of sucrose degradation primarily to CH4 and CO2 was constructed, with acetate as the key methanogenic precursor. In addition, the effect of agar immobilization on the activity of the consortium was determined. The primary fermentative organism, Escherichia coli, produced acetate, formate, H2, and CO2 (known substrates for methanogens), as well as ethanol and lactate, compounds that are not substrates for methanogens. Oxidation of the nonmethanogenic substrates, lactate and ethanol, to acetate was mediated by the addition of Acetobacterium woodii and Desulfovibrio vulgaris. The methanogenic stage was accomplished by the addition of the acetophilic methanogen Methanosarcina barkeri and the hydrogenophilic methanogen Methanobacterium formicicum. Results of studies with low substrate concentrations (0.05 to 0.2% [wt/vol]), a growth-limiting medium, and the five-component consortium indicated efficient conversion (40%) of sucrose carbon to CH4. Significant decreases in yields of CH4 and rates of CH4 production were observed if any component of the consortium was omitted. Approximately 70% of the CH4 generated occurred via acetate. Agar-immobilized cells of the consortium exhibited yields of CH4 and rates of CH4 production from sucrose similar to those of nonimmobilized cells. The rate of CH4 production decreased by 25% when cysteine was omitted from reaction conditions and by 40% when the immobilized consortium was stored for 1 week at 4°C. PMID:16346452

  12. Analysis of microbial communities in the oil reservoir subjected to CO2-flooding by using functional genes as molecular biomarkers for microbial CO2 sequestration.

    PubMed

    Liu, Jin-Feng; Sun, Xiao-Bo; Yang, Guang-Chao; Mbadinga, Serge M; Gu, Ji-Dong; Mu, Bo-Zhong

    2015-01-01

    Sequestration of CO2 in oil reservoirs is considered to be one of the feasible options for mitigating atmospheric CO2 building up and also for the in situ potential bioconversion of stored CO2 to methane. However, the information on these functional microbial communities and the impact of CO2 storage on them is hardly available. In this paper a comprehensive molecular survey was performed on microbial communities in production water samples from oil reservoirs experienced CO2-flooding by analysis of functional genes involved in the process, including cbbM, cbbL, fthfs, [FeFe]-hydrogenase, and mcrA. As a comparison, these functional genes in the production water samples from oil reservoir only experienced water-flooding in areas of the same oil bearing bed were also analyzed. It showed that these functional genes were all of rich diversity in these samples, and the functional microbial communities and their diversity were strongly affected by a long-term exposure to injected CO2. More interestingly, microorganisms affiliated with members of the genera Methanothemobacter, Acetobacterium, and Halothiobacillus as well as hydrogen producers in CO2 injected area either increased or remained unchanged in relative abundance compared to that in water-flooded area, which implied that these microorganisms could adapt to CO2 injection and, if so, demonstrated the potential for microbial fixation and conversion of CO2 into methane in subsurface oil reservoirs. PMID:25873911

  13. Microbial Community Succession During Lactate Amendment of Chromium Contaminated Groundwater Reveals a Predominance of Pelosinus spp.

    SciTech Connect

    Mosher, Jennifer J; Phelps, Tommy Joe; Drake, Meghan M; Campbell, James H; Moberly, James G; Schadt, Christopher Warren; Podar, Mircea; Brown, Steven D; Hazen, Terry; Arkin, Adam; Palumbo, Anthony Vito; Faybishenko, Boris A; Elias, Dwayne A

    2012-01-01

    Microbial community structure and metabolism in contaminated ecosystems are potentially controlled not only by the different populations within the community, but a myriad of dynamic physicochemical parameters as well. The goal of the current work was to determine the impact of organic acid enrichment, in this case lactate, on the succession of the native microbial community from a contaminated groundwater aquifer. Triplicate anaerobic, continuous-flow glass reactors were inoculated with Hanford 100-H groundwater and incubated for 95 days to obtain a stable, enriched community. The microbial community experienced a shift in the population dynamics over time to eventually form a community with far less diversity than the original. The final community was dominated by Pelosinus spp. and to a lesser degree, Acetobacterium spp. with small amounts of other bacteria and archaea including methanogens. The resultant diversity was far decreased from 63 genera within 12 phyla to 11 bacterial genera (from three phyla) and 2 archaeal genera (from one phylum). Isolation efforts were successful in attaining new species of Pelosinus and known members of Methanosarcina barkerii along with several sulfate- and Fe(III)- reducing consortia members. The continuous-flow reactors allowed for testing physiochemical factors with microbial community dynamics on a smaller, replicable, scale while also facilitating the isolation of several previously uncultured community members. These lab-scale simulations will presumably allow for a deeper understanding of the community metabolism with specific carbon amendments that can inform future in situ efforts.

  14. High-resolution structure and mechanism of an F/V-hybrid rotor ring in a Na⁺-coupled ATP synthase.

    PubMed

    Matthies, Doreen; Zhou, Wenchang; Klyszejko, Adriana L; Anselmi, Claudio; Yildiz, Özkan; Brandt, Karsten; Müller, Volker; Faraldo-Gómez, José D; Meier, Thomas

    2014-01-01

    All rotary ATPases catalyse the interconversion of ATP and ADP-Pi through a mechanism that is coupled to the transmembrane flow of H(+) or Na(+). Physiologically, however, F/A-type enzymes specialize in ATP synthesis driven by downhill ion diffusion, while eukaryotic V-type ATPases function as ion pumps. To begin to rationalize the molecular basis for this functional differentiation, we solved the crystal structure of the Na(+)-driven membrane rotor of the Acetobacterium woodii ATP synthase, at 2.1 Å resolution. Unlike known structures, this rotor ring is a 9:1 heteromer of F- and V-type c-subunits and therefore features a hybrid configuration of ion-binding sites along its circumference. Molecular and kinetic simulations are used to dissect the mechanisms of Na(+) recognition and rotation of this c-ring, and to explain the functional implications of the V-type c-subunit. These structural and mechanistic insights indicate an evolutionary path between synthases and pumps involving adaptations in the rotor ring. PMID:25381992

  15. Microbial reduction and precipitation of vanadium (V) in groundwater by immobilized mixed anaerobic culture.

    PubMed

    Zhang, Baogang; Hao, Liting; Tian, Caixing; Yuan, Songhu; Feng, Chuanping; Ni, Jinren; Borthwick, Alistair G L

    2015-09-01

    Vanadium is an important contaminant impacted by natural and industrial activities. Vanadium (V) reduction efficiency as high as 87.0% was achieved by employing immobilized mixed anaerobic sludge as inoculated seed within 12h operation, while V(IV) was the main reduction product which precipitated instantly. Increasing initial V(V) concentration resulted in the decrease of V(V) removal efficiency, while this index increased first and then decreased with the increase of initial COD concentration, pH and conductivity. High-throughput 16S rRNA gene pyrosequencing analysis indicated the decreased microbial diversity. V(V) reduction was realized through dissimilatory reduction process by significantly enhanced Lactococcus and Enterobacter with oxidation of lactic and acetic acids from fermentative microorganisms such as the enriched Paludibacter and the newly appeared Acetobacterium, Oscillibacter. This study is helpful to detect new functional species for V(V) reduction and constitutes a step ahead in developing in situ bioremediations of vanadium contamination. PMID:26067477

  16. A novel way to utilize hydrogen and carbon dioxide in acidogenic reactor through homoacetogenesis.

    PubMed

    Yan, Bing Hua; Selvam, Ammaiyappan; Xu, Su Yun; Wong, Jonathan W C

    2014-05-01

    This study investigated the potential of Acetobacterium woodii, a homoacetogen, in co-culture with common acetogens for acetate production during glucose fermentation. Three types of inocula, A. woodii (AW), heat-treated sludge (HTS) and co-culture of A. woodii and heat-treated sludge (AW-HTS) were investigated. Results showed that ∼ 150 mM of glucose was almost completely converted to biomass, gases and other products in co-culture. The addition of A. woodii induced homoacetogenic fermentation in AW-HTS during the first 3 days, as evidenced by the decreased hydrogen production and acetate dominance (>90%, corresponding to 1.19 mol acetate/mol glucose) in total soluble products. However, due to the unfavorable environmental conditions, metabolic pathway in AW-HTS treatment shifted towards butyrate type at the end of the experiment. Bacterial diversity analysis indicated that species supporting growth of A. woodii were dominant during the first several days and their abundance gradually decreased until the end of experiment. PMID:24657755

  17. Distribution of coenzyme F420 and properties of its hydrolytic fragments.

    PubMed

    Eirich, L D; Vogels, G D; Wolfe, R S

    1979-10-01

    The ability of hydrolytic products of coenzyme F420 to substitute for F420 in the hydrogenase and nicotinamide adenine dinucleotide phosphate-liniked hydrogenase systems of Methanobacterium strain M.o.H. was kinetically determined. The nicotinamide adenine dinucleotide phosphate-linked hydrogenase system was employed to quantitate the levels of F420 in a number of methanogenic bacteria as well as in some nonmethanogens. Methanobacterium ruminantium and Methanosarcina barkeri contained low levels of F420, whereas other methanogens tested contained high levels (100 to 400 mg/kg of cells). F420 from six of the seven methanogens was tested by thin-layer electrophoresis and was found to be electrophoretically identical to that purified from Methanobacterium strain M.o.H. The only exception was M. barkeri, which contained a more electronegative derivative of F420. Acetobacterium woodii, Escherichia coli, and yeast extract contained no compounds able to substitute for F420 in the nicotinamide adenine dinucleotide phosphate-linked hydrogenase system. PMID:40952

  18. Distribution of coenzyme F420 and properties of its hydrolytic fragments.

    PubMed Central

    Eirich, L D; Vogels, G D; Wolfe, R S

    1979-01-01

    The ability of hydrolytic products of coenzyme F420 to substitute for F420 in the hydrogenase and nicotinamide adenine dinucleotide phosphate-liniked hydrogenase systems of Methanobacterium strain M.o.H. was kinetically determined. The nicotinamide adenine dinucleotide phosphate-linked hydrogenase system was employed to quantitate the levels of F420 in a number of methanogenic bacteria as well as in some nonmethanogens. Methanobacterium ruminantium and Methanosarcina barkeri contained low levels of F420, whereas other methanogens tested contained high levels (100 to 400 mg/kg of cells). F420 from six of the seven methanogens was tested by thin-layer electrophoresis and was found to be electrophoretically identical to that purified from Methanobacterium strain M.o.H. The only exception was M. barkeri, which contained a more electronegative derivative of F420. Acetobacterium woodii, Escherichia coli, and yeast extract contained no compounds able to substitute for F420 in the nicotinamide adenine dinucleotide phosphate-linked hydrogenase system. PMID:40952

  19. Sugar phosphorylation activity in ruminal acetogens.

    PubMed

    Jiang, W; Pinder, R S; Patterson, J A; Ricke, S C

    2012-01-01

    Acetogenic bacteria Acetitomaculum ruminis, Acetobacterium woodii, and Eubacterium limosum were compared for phosphoenolpyruvate (PEP) and ATP-dependent phosphorylation of glucose and 2-deoxy-glucose. Rate of phosphorylation activity was measured in toluene-treated acetogenic cells using PEP and ATP and radiolabled glucose or 2-deoxy glucose. Eubacterium limosum, most likely has a glucose phosphotransferase system (PTS). In contrast, A. ruminis, and A. woodii had PEP-dependent glucose phosphorylation rates very similar to control rates, suggesting the lack of PTS activity. These results were confirmed by PEP dependent 2-deoxyglucose phosphorylation data. The rates of ATP-dependent glucose phosphorylation were higher than PEP-dependent glucose dependent in all organisms surveyed. Only E. limosum appeared to have PTS. The presence of PTS in E. limosum could explain why it is not capable of utilizing sugars and H(2)/CO(2) simultaneously and why acetogenesis is not as prominant in the rumen because of the availability of carbohydrates as alternative energy substrates. PMID:22423990

  20. /sup 13/C and /sup 61/Ni isotope substitutions confirm the presence of a nickel(III)-carbon species in acetogenic CO dehydrogenases

    SciTech Connect

    Ragsdale, S.W.; Ljungdahl, L.G.; DerVartanian, D.V.

    1983-09-15

    The nickel-containing CO dehydrogenase from Acetobacterium woodii and Clostridium thermoaceticum were studied by EPR spectroscopy in order to define the components involved in the EPR spectrum obtained by reaction of the enzymes with the substrate, CO. Using isotopic substitution techniques, these experiments unequivocally establish that a nickel-carbon species is involved in the g=2.08, 2.02 EPR signal. Comparing the /sup 61/Ni- and /sup 59/Ni-substituted enzymes, the g=2.08 component of the resonance was found to be mainly due to nickel with a smaller contribution by the carbon species. Reaction of the CO dehydrogenase with (/sup 13/C)CO versus (/sup 12/C)CO showed that a carbon species, formed from CO, was the major contributor to the g=2.02 EPR signal. In addition, the oxidized CO dehydrogenase was found to exhibit a Ni(III) EPR signal analogous to that of the hydrogenase from the methanogenic and sulfate-reducing bacteria. 19 references, 3 figures.

  1. Respiratory chain supercomplexes of mitochondria and bacteria.

    PubMed

    Schägger, Hermann

    2002-09-10

    Respiratory chain complexes are fragments of larger structural and functional units, the respiratory chain supercomplexes or "respirasomes", which exist in bacterial and mitochondrial membranes. Supercomplexes of mitochondria and bacteria contain complexes III, IV, and complex I, with the notable exception of Saccharomyces cerevisiae, which does not possess complex I. These supercomplexes often are stable to sonication but sensitive to most detergents except digitonin. In S. cerevisiae, a major component linking complexes III and IV together is cardiolipin.In Paracoccus denitrificans, complex I itself is rather detergent-sensitive and thus could not be obtained in detergent-solubilized form so far. However, it can be isolated as part of a supercomplex. Stabilization of complex I by binding to complex III was also found in human mitochondria. Further functional roles of the organization in a supercomplex are catalytic enhancement by reducing diffusion distances of substrates or, depending on the organism, channelling of the substrates quinone and cytochrome c. This makes redox reactions less dependent of midpoint potentials of substrates, and permits electron flow at low degree of substrate reduction.A dimeric state of ATP synthase seems to be specific for mitochondria. Exclusively, monomeric ATP synthase was found in Acetobacterium woodii, in P. denitrificans, and in spinach chloroplasts. PMID:12206908

  2. Importance of tetrahydrofolate and ATP in the anaerobic O-demethylation reaction for phenylmethylethers.

    PubMed

    Berman, M H; Frazer, A C

    1992-03-01

    DL-Tetrahydrofolate (THF) and ATP were necessary for the anaerobic O-demethylation of phenylmethylethers in cell extracts of the type strain (ATCC 29683) of the homoacetogen Acetobacterium woodii. The reactants for this enzymatic activity have not been previously demonstrated in any system, nor has the mediating enzyme been studied. An assay using reaction mixtures containing 1 mM THF, 2 mM ATP, and 2 mM hydroferulate (i.e., 4-hydroxy,3-methoxyphenylpropionate) was developed and was performed under stringent anaerobic conditions. Pyridine nucleotides and several other possible cofactors were tested but had no effect on the activity. After centrifugation of disrupted cells at 27,000 x g, the activity was found primarily in the supernatant, which had a specific activity of 14.2 +/- 0.5 nmol/min/mg of protein. At saturating levels of each of the other two substrates, apparent Km values for the variable substrate were 0.65 mM hydroferulate, 0.27 mM ATP, and 0.17 mM THF. Activity was significantly decreased when extract was preincubated at 60 degrees C and was completely lost after preincubation in air for 30 min. Thus, the soluble anaerobic O-demethylating enzyme system of A. woodii is oxygen sensitive. The THF- and ATP-dependent activity measurable in the soluble fraction of cell extracts constituted about 34% of the activity seen with intact cells. PMID:1575495

  3. Methylenetetrahydrofolate dehydrogenase from Clostridium formicoaceticum and methylenetetrahydrofolate dehydrogenase, methenyltetrahydrofolate cyclohydrolase (combined) from Clostridium thermoaceticum

    SciTech Connect

    Ljungdahl, L.G.; O'Brien, W.E.; Moore, M.R.; Liu, M.T.

    1980-01-01

    Methylenetetrahydrofolate dehydrogenase is widely distributed and has been found in every cell type investigated. The NAD-specific enzyme has been purified to homogeneity from Clostridium formicoaceticum and the NADP-specific enzyme has been obtained from Clostridium thermoaceticum. Other sources of the NADP-specific enzyme are Streptococcus species, Escherichia coli, Clostridium cylindrosporum, Salmonella typhimurium, yeast, liver from various animals, calf thymus, and plants. The NAD-specific enzyme has been demonstrated in Acetobacterium woodii, some methane bacteria, and in Ehrlich ascites tumor cells. Of considerable interest are the observations that in porcine and ovine livers, as well as in yeast, methylenetetrahydrofolate dehydrogenase purified to homogeneity also contains methylenetetrahydrofolate cyclohydrolase and formyltetrahydrofolate synthetase activities. Now it appears that the purified methylenetetrahydrofolate dehydrogenase from C. thermoaceticum also has cyclohydrolase but not synthetase activity. Methylenetetrahydrofolate dehydrogenase has been discussed previously in this series, as has methenyltetrahydrofolate cyclohydrolase. In C. formicoaceticum and C. thermoaceticum these tetrahydrofolate-dependent enzymes participate in a sequence of metabolic reactions by which carbon dioxide is reduced to the methyl group of 5-methyltetrahydrofolate which in turn is utilized for the synthesis of acetate. This pathway provides the mechanism for disposing of reducing equivalents generated in glycolysis.

  4. A bacterial electron-bifurcating hydrogenase.

    PubMed

    Schuchmann, Kai; Müller, Volker

    2012-09-01

    The Wood-Ljungdahl pathway of anaerobic CO(2) fixation with hydrogen as reductant is considered a candidate for the first life-sustaining pathway on earth because it combines carbon dioxide fixation with the synthesis of ATP via a chemiosmotic mechanism. The acetogenic bacterium Acetobacterium woodii uses an ancient version of the pathway that has only one site to generate the electrochemical ion potential used to drive ATP synthesis, the ferredoxin-fueled, sodium-motive Rnf complex. However, hydrogen-based ferredoxin reduction is endergonic, and how the steep energy barrier is overcome has been an enigma for a long time. We have purified a multimeric [FeFe]-hydrogenase from A. woodii containing four subunits (HydABCD) which is predicted to have one [H]-cluster, three [2Fe2S]-, and six [4Fe4S]-clusters consistent with the experimental determination of 32 mol of Fe and 30 mol of acid-labile sulfur. The enzyme indeed catalyzed hydrogen-based ferredoxin reduction, but required NAD(+) for this reaction. NAD(+) was also reduced but only in the presence of ferredoxin. NAD(+) and ferredoxin reduction both required flavin. Spectroscopic analyses revealed that NAD(+) and ferredoxin reduction are strictly coupled and that they are reduced in a 1:1 stoichiometry. Apparently, the multimeric hydrogenase of A. woodii is a soluble energy-converting hydrogenase that uses electron bifurcation to drive the endergonic ferredoxin reduction by coupling it to the exergonic NAD(+) reduction. PMID:22810230

  5. Importance of tetrahydrofolate and ATP in the anaerobic O-demethylation reaction for phenylmethylethers

    SciTech Connect

    Berman, M.H.; Frazer, A.C. )

    1992-03-01

    DL-Tetrahydrofolate (THF) and ATP were necessary for the anaerobic O-demethylation of phenylmethylethers in cell extracts of the type strain (ATCC 29683) of the homoacetogen Acetobacterium woodii. The reactants for this enzymatic activity have not been previously demonstrated in any system, nor has the mediating enzyme been studied. An assay using reaction mixtures containing 1 mM THF, 2 mM ATP, and 2 mM hydroferulate (i.e., 4-hydroxy,3-methoxyphenylpropionate) was developed and was performed under stringent anaerobic conditions. Pyridine nucleotides and several other possible cofactors were tested but had no effect on the activity. After centrifugation of disrupted cells at 27,000 x g, the activity was found primarily in the supernatant, which had a specific activity of 14.2 {plus minus} 0.5 nmol/min/mg of protein. At saturating levels of each of the other two substrates, apparent K{sub m} values for the variable substrate were 0.65 mM hydroferulate, 0.27 mM ATP, and 0.17 mM THF. Activity was significantly decreased when extract was preincubated at 60C and was completely lost after preincubation in air for 30 min. Thus, the soluble anaerobic O-demethylating enzyme system of A. woodii is oxygen sensitive. The THF- and ATP-dependent activity measurable in the soluble fraction of cell extracts constituted about 34% of the activity seen with intact cells.

  6. Methanogenesis from sucrose by defined immobilized consortia.

    PubMed

    Jones, W J; Guyot, J P; Wolfe, R S

    1984-01-01

    A bacterial consortium capable of sucrose degradation primarily to CH(4) and CO(2) was constructed, with acetate as the key methanogenic precursor. In addition, the effect of agar immobilization on the activity of the consortium was determined. The primary fermentative organism, Escherichia coli, produced acetate, formate, H(2), and CO(2) (known substrates for methanogens), as well as ethanol and lactate, compounds that are not substrates for methanogens. Oxidation of the nonmethanogenic substrates, lactate and ethanol, to acetate was mediated by the addition of Acetobacterium woodii and Desulfovibrio vulgaris. The methanogenic stage was accomplished by the addition of the acetophilic methanogen Methanosarcina barkeri and the hydrogenophilic methanogen Methanobacterium formicicum. Results of studies with low substrate concentrations (0.05 to 0.2% [wt/vol]), a growth-limiting medium, and the five-component consortium indicated efficient conversion (40%) of sucrose carbon to CH(4). Significant decreases in yields of CH(4) and rates of CH(4) production were observed if any component of the consortium was omitted. Approximately 70% of the CH(4) generated occurred via acetate. Agar-immobilized cells of the consortium exhibited yields of CH(4) and rates of CH(4) production from sucrose similar to those of nonimmobilized cells. The rate of CH(4) production decreased by 25% when cysteine was omitted from reaction conditions and by 40% when the immobilized consortium was stored for 1 week at 4 degrees C. PMID:16346452

  7. [Sugar phosphorylation activities in acetogenic bacteria].

    PubMed

    Jiang, W; Patterson, J A

    1999-12-01

    Seven acetogenic bacteria (Acetitomaculum ruminis, Acetobacterium woodii, Eubacterium limosum as well as isolates A2, A4, A10 and H3HH) were tested for PEP- and ATP-dependent phosphorylation of glucose and 2-deoxyglucose. Although all organisms had detectable phosphorylation activity, substantial variation existed in the rates of both PEP- and ATP-dependent phosphorylation. Isolate Alo had the highest rate of PEP-dependent phosphorylation of 11.62 nmol.L-1.mg-1.min-1. Isolate A10, H3HH as well as E. limosum most likely have a glucose phosphotransferase system(PTS). In contrast, A ruminis, A. woodii and isolate A2, A4 had PEP-dependent glucose phosphorylation rates very similar to control rates, suggesting the lack of PTS activity. The rates of ATP-dependent glucose phosphorylation were higher than PEP-dependent phosphorylation in all organisms surveyed. However, substantial variation existed in the rates of ATP-dependent glucose phosphorylation. The glucose PTS of isolates A10 and H3HH were induced by the presence of extracellular glucose. Moreover, the specific activity of the glucose PTS of both isolates increased as cultures progressed from the early log to late log phase of growth. ATP- and PEP-dependent maltose and sucrose phosphorylation was detected in isolates A10 and H3HH. Although activity was detected in both isolates(A10 and H3HH), the rate of activity varied considerably, depending on the sugar and organism tested. PMID:12555560

  8. Biomass-derived syngas fermentation into biofuels: Opportunities and challenges.

    PubMed

    Munasinghe, Pradeep Chaminda; Khanal, Samir Kumar

    2010-07-01

    The conversion of biomass-derived synthesis gas (or syngas in brief) into biofuels by microbial catalysts (such as Clostridium ljungdahlii, Clostridium autoethanogenum, Acetobacterium woodii, Clostridium carboxidivorans and Peptostreptococcus productus) has gained considerable attention as a promising alternative for biofuel production in the recent past. The utilization of the whole biomass, including lignin, irrespective of biomass quality, the elimination of complex pre-treatment steps and costly enzymes, a higher specificity of biocatalysts, an independence of the H(2):CO ratio for bioconversion, bioreactor operation at ambient conditions, and no issue of noble metal poisoning are among the major advantages of this process. Poor mass transfer properties of the gaseous substrates (mainly CO and H(2)) and low ethanol yield of biocatalysts are the biggest challenges preventing the commercialization of syngas fermentation technology. This paper critically reviews the existing literature in biomass-derived syngas fermentation into biofuels, specifically, different biocatalysts, factors affecting syngas fermentation, and mass transfer. The paper also outlines the major challenges of syngas fermentation, key performance index and technology road map, and discusses the further research needs. PMID:20096574

  9. Anaerobic O-demethylation of phenylmethylethers

    SciTech Connect

    Frazer, A.C.; Young, L.Y.

    1990-01-01

    Anaerobic O-demethylation (AOD) of phenylmethylethers is a process of both basic and applied significance. The aryl-O-methyl ethers are abundant in natural products, particularly as components of lignin. They are present as methoxylated lignin monomers in anaerobic environments and can be completely degraded there by mixed microbial populations. AOD is an essential early step in this process, and it is also a key reaction in the utilization of the O-methyl substituent as a C-one substrate by acetogens. An understanding of the AOD reaction mechanism might suggest new ways in which chemicals could be derived from lignocellulosic materials. The biochemical mechanism for the anaerobic cleavage of the aryl-O-methyl ether bond is an intriguing, but relatively unexplored process. In contrast to aerobic O-demethylating enzymes, AOD appears to involve methyl group transfer. Thus, novel biochemical information on an important biotransformation reaction will be gained from the research proposed. Recently, we have shown that AOD activity is inducible and have developed an assay for detecting AOD activity in cell-free extracts of Acetobacterium woodii. AOD activity is stimulated in vitro by the addition of ATP (1mM) and pyruvate (30 mM), the K{sub M} for vanillate being 0.4 mM. In collaboration with protein purification experts, we proposed to purify the AOD enzyme and characterize the protein(s) and the enzymatic reaction involved. 8 figs., 5 tabs.

  10. Carbon isotope fractionation of 11 acetogenic strains grown on H2 and CO2.

    PubMed

    Blaser, Martin B; Dreisbach, Lisa K; Conrad, Ralf

    2013-03-01

    Acetogenic bacteria are able to grow autotrophically on hydrogen and carbon dioxide by using the acetyl coenzyme A (acetyl-CoA) pathway. Acetate is the end product of this reaction. In contrast to the fermentative route of acetate production, which shows almost no fractionation of carbon isotopes, the acetyl-CoA pathway has been reported to exhibit a preference for light carbon. In Acetobacterium woodii the isotope fractionation factor (ε) for (13)C and (12)C has previously been reported to be ε = -58.6‰. To investigate whether such a strong fractionation is a general feature of acetogenic bacteria, we measured the stable carbon isotope fractionation factor of 10 acetogenic strains grown on H(2) and CO(2). The average fractionation factor was ε(TIC) = -57.2‰ for utilization of total inorganic carbon and ε(acetate) = -54.6‰ for the production of acetate. The strongest fractionation was found for Sporomusa sphaeroides (ε(TIC) = -68.3‰), the lowest fractionation for Morella thermoacetica (ε(TIC) = -38.2‰). To investigate the reproducibility of our measurements, we determined the fractionation factor of 21 biological replicates of Thermoanaerobacter kivui. In general, our study confirmed the strong fractionation of stable carbon during chemolithotrophic acetate formation in acetogenic bacteria. However, the specific characteristics of the bacterial strain, as well as the cultural conditions, may have a moderate influence on the overall fractionation. PMID:23275504

  11. Bacterial Na+-translocating ferredoxin:NAD+ oxidoreductase.

    PubMed

    Biegel, Eva; Müller, Volker

    2010-10-19

    The anaerobic acetogenic bacterium Acetobacterium woodii carries out a unique type of Na(+)-motive, anaerobic respiration with caffeate as electron acceptor, termed "caffeate respiration." Central, and so far the only identified membrane-bound reaction in this respiration pathway, is a ferredoxin:NAD(+) oxidoreductase (Fno) activity. Here we show that inverted membrane vesicles of A. woodii couple electron transfer from reduced ferredoxin to NAD(+) with the transport of Na(+) from the outside into the lumen of the vesicles. Na(+) transport was electrogenic, and accumulation was inhibited by sodium ionophores but not protonophores, demonstrating a direct coupling of Fno activity to Na(+) transport. Results from inhibitor studies are consistent with the hypothesis that Fno activity coupled to Na(+) translocation is catalyzed by the Rnf complex, a membrane-bound, iron-sulfur and flavin-containing electron transport complex encoded by many bacterial and some archaeal genomes. Fno is a unique type of primary Na(+) pump and represents an early evolutionary mechanism of energy conservation that expands the redox range known to support life. In addition, it explains the lifestyle of many anaerobic bacteria and gives a mechanistic explanation for the enigma of the energetic driving force for the endergonic reduction of ferredoxin with NADH plus H(+) as reductant in a number of aerobic bacteria. PMID:20921383

  12. Hybrid rotors in F1F(o) ATP synthases: subunit composition, distribution, and physiological significance.

    PubMed

    Brandt, Karsten; Müller, Volker

    2015-09-01

    The c ring of the Na+ F1F(o) ATP synthase from the anaerobic acetogenic bacterium Acetobacterium woodii is encoded by three different genes: atpE1, atpE2 and atpE3. Subunit c1 is similar to typical V-type c subunits and has four transmembrane helices with one ion binding site. Subunit c2 and c3 are identical at the amino acid level and are typical F-type c subunits with one ion binding site in two transmembrane helices. All three constitute a hybrid F(o)V(o) c ring, the first found in nature. To analyze whether other species may have similar hybrid rotors, we searched every genome sequence publicly available as of 23 February 2015 for F1F(o) ATPase operons that have more than one gene encoding the c subunit. This revealed no other species that has three different c subunit encoding genes but twelve species that encode one F(o)- and one V(o)-type c subunit in one operon. Their c subunits have the conserved binding motif for Na+. The organisms are all anaerobic. The advantage of hybrid c rings for the organisms in their environments is discussed. PMID:25838297

  13. Electrosynthesis of organic compounds from carbon dioxide is catalyzed by a diversity of acetogenic microorganisms.

    PubMed

    Nevin, Kelly P; Hensley, Sarah A; Franks, Ashley E; Summers, Zarath M; Ou, Jianhong; Woodard, Trevor L; Snoeyenbos-West, Oona L; Lovley, Derek R

    2011-05-01

    Microbial electrosynthesis, a process in which microorganisms use electrons derived from electrodes to reduce carbon dioxide to multicarbon, extracellular organic compounds, is a potential strategy for capturing electrical energy in carbon-carbon bonds of readily stored and easily distributed products, such as transportation fuels. To date, only one organism, the acetogen Sporomusa ovata, has been shown to be capable of electrosynthesis. The purpose of this study was to determine if a wider range of microorganisms is capable of this process. Several other acetogenic bacteria, including two other Sporomusa species, Clostridium ljungdahlii, Clostridium aceticum, and Moorella thermoacetica, consumed current with the production of organic acids. In general acetate was the primary product, but 2-oxobutyrate and formate also were formed, with 2-oxobutyrate being the predominant identified product of electrosynthesis by C. aceticum. S. sphaeroides, C. ljungdahlii, and M. thermoacetica had high (>80%) efficiencies of electrons consumed and recovered in identified products. The acetogen Acetobacterium woodii was unable to consume current. These results expand the known range of microorganisms capable of electrosynthesis, providing multiple options for the further optimization of this process. PMID:21378039

  14. An electron-bifurcating caffeyl-CoA reductase.

    PubMed

    Bertsch, Johannes; Parthasarathy, Anutthaman; Buckel, Wolfgang; Müller, Volker

    2013-04-19

    A low potential electron carrier ferredoxin (E0' ≈ -500 mV) is used to fuel the only bioenergetic coupling site, a sodium-motive ferredoxin:NAD(+) oxidoreductase (Rnf) in the acetogenic bacterium Acetobacterium woodii. Because ferredoxin reduction with physiological electron donors is highly endergonic, it must be coupled to an exergonic reaction. One candidate is NADH-dependent caffeyl-CoA reduction. We have purified a complex from A. woodii that contains a caffeyl-CoA reductase and an electron transfer flavoprotein. The enzyme contains three subunits encoded by the carCDE genes and is predicted to have, in addition to FAD, two [4Fe-4S] clusters as cofactor, which is consistent with the experimental determination of 4 mol of FAD, 9 mol of iron, and 9 mol of acid-labile sulfur. The enzyme complex catalyzed caffeyl-CoA-dependent oxidation of reduced methyl viologen. With NADH as donor, it catalyzed caffeyl-CoA reduction, but this reaction was highly stimulated by the addition of ferredoxin. Spectroscopic analyses revealed that ferredoxin and caffeyl-CoA were reduced simultaneously, and a stoichiometry of 1.3:1 was determined. Apparently, the caffeyl-CoA reductase-Etf complex of A. woodii uses the novel mechanism of flavin-dependent electron bifurcation to drive the endergonic ferredoxin reduction with NADH as reductant by coupling it to the exergonic NADH-dependent reduction of caffeyl-CoA. PMID:23479729

  15. Clostridium ljungdahlii represents a microbial production platform based on syngas.

    PubMed

    Köpke, Michael; Held, Claudia; Hujer, Sandra; Liesegang, Heiko; Wiezer, Arnim; Wollherr, Antje; Ehrenreich, Armin; Liebl, Wolfgang; Gottschalk, Gerhard; Dürre, Peter

    2010-07-20

    Clostridium ljungdahlii is an anaerobic homoacetogen, able to ferment sugars, other organic compounds, or CO(2)/H(2) and synthesis gas (CO/H(2)). The latter feature makes it an interesting microbe for the biotech industry, as important bulk chemicals and proteins can be produced at the expense of CO(2), thus combining industrial needs with sustained reduction of CO and CO(2) in the atmosphere. Sequencing the complete genome of C. ljungdahlii revealed that it comprises 4,630,065 bp and is one of the largest clostridial genomes known to date. Experimental data and in silico comparisons revealed a third mode of anaerobic homoacetogenic metabolism. Unlike other organisms such as Moorella thermoacetica or Acetobacterium woodii, neither cytochromes nor sodium ions are involved in energy generation. Instead, an Rnf system is present, by which proton translocation can be performed. An electroporation procedure has been developed to transform the organism with plasmids bearing heterologous genes for butanol production. Successful expression of these genes could be demonstrated, leading to formation of the biofuel. Thus, C. ljungdahlii can be used as a unique microbial production platform based on synthesis gas and carbon dioxide/hydrogen mixtures. PMID:20616070

  16. Dependence on membrane components of methanogenesis from methyl-CoM with formaldehyde or molecular hydrogen as electron donors.

    PubMed

    Deppenmeier, U; Blaut, M; Gottschalk, G

    1989-12-01

    Methane formation from 2-(methylthio)-ethanesulfonate (methyl-CoM) and H2 by the soluble fraction from the methanogenic bacterium strain Gö1 was stimulated up to tenfold by the addition of the membrane fraction. This stimulation was observed with membranes from various methanogenic species belonging to different phylogenetic families, but not with membranes from Escherichia coli or Acetobacterium woodii. Treatment of the membranes with strong oxidants, i.e. O2 and K3[Fe(CN)6], or with SH reagents, i.e. Ag+, p-chloromercuribenzoate or iodoacetamide, caused an irreversible decrease or loss in stimulatory activity, as did heat treatment at temperatures above 78 degrees C. Methanogenesis from methyl-CoM with formaldehyde instead of H2 as electron donor depended similarly on the membrane fraction. With membranes, 1 mol HCHO was oxidized to 1 mol CO2 and allowed the formation of 2 mol CH4 from 2 mol CH3-CoM. Without membranes, per mol of HCHO oxidized 1 mol H2 was formed and 1 mol CH4 was produced from CH3-CoM; the rate was 10-20% of that in the presence of membranes. When methyl-CoM was replaced by an artificial electron acceptor system consisting of methylviologen and metronidazole, the formaldehyde-oxidizing activity was no longer stimulated by the membrane fraction. These results demonstrate for the first time an essential function of membrane components in methanogenic electron transfer. PMID:2513188

  17. Carbon isotope fractionation and the acetyl-CoA pathway

    NASA Astrophysics Data System (ADS)

    Blaser, Martin; Conrad, Ralf

    2010-05-01

    Homoacetogenic bacteria can catalyze the reductive synthesis of acetate from CO2 via the acetyl-CoA pathway. Besides this unifying property homoacetogenic bacteria constitute a metabolically and phylogenetically diverse bacteriological group. Therefore their environmental role is difficult to address. It has been recognized that in methanogenic environments homoacetogenic bacteria contribute to the degradation of organic matter. The natural abundance of 13C may be used to understand the functional impact of homoacetogenic bacteria in the soil environment. To distinguish the acetyl-CoA pathway from other dominant processes, the isotopic composition of acetate and CO2 can be determined and the fractionation factors of the individual processes may be used to discriminate between the dominant pathways. To characterize the fractionation factor associated with the acetyl-CoA pathway the phylogenetic and metabolic diversity needs to be considered. Therefore the fractionation factor of substrate utilization and product formation of different homoacetogens (Acetobacterium woodii, Sporomusa ovata, Thermoanaerobacter kivui, Morella thermoautotrophica) has been studied under pure culture conditions in two defined minimal medium with H2/CO2 as sole source of carbon and energy. It became obvious that the cultivation conditions have a major impact on the obtained fractionation factors.

  18. 13C and 61Ni isotope substitutions confirm the presence of a nickel (III)-carbon species in acetogenic CO dehydrogenases.

    PubMed

    Ragsdale, S W; Ljungdahl, L G; DerVartanian, D V

    1983-09-15

    The nickel-containing CO dehydrogenases from Acetobacterium woodii and Clostridium thermoaceticum were studied by EPR spectroscopy in order to define the components involved in the EPR spectrum obtained by reaction of the enzymes with the substrate, CO. Using isotopic substitution techniques, these experiments unequivocally establish that a nickel-carbon species is involved in the g = 2.08, 2.02 EPR signal. Comparing the 61Ni- and 59Ni-substituted enzymes, the g = 2.08 component of the resonance was found to be mainly due to nickel with a smaller contribution by the carbon species. Reaction of the CO dehydrogenase with [13C]CO versus [12C]CO showed that a carbon species, formed from CO, was the major contributor to the g = 2.02 EPR signal. In addition, the oxidized CO dehydrogenase was found to exhibit a Ni (III) EPR signal analogous to that of the hydrogenases from the methanogenic and sulfate-reducing bacteria. PMID:6312988

  19. A novel mode of lactate metabolism in strictly anaerobic bacteria.

    PubMed

    Weghoff, Marie Charlotte; Bertsch, Johannes; Müller, Volker

    2015-03-01

    Lactate is a common substrate for major groups of strictly anaerobic bacteria, but the biochemistry and bioenergetics of lactate oxidation is obscure. The high redox potential of the pyruvate/lactate pair of E0 ' = -190 mV excludes direct NAD(+) reduction (E0 ' = -320 mV). To identify the hitherto unknown electron acceptor, we have purified the lactate dehydrogenase (LDH) from the strictly anaerobic, acetogenic bacterium Acetobacterium woodii. The LDH forms a stable complex with an electron-transferring flavoprotein (Etf) that exhibited NAD(+) reduction only when reduced ferredoxin (Fd(2-) ) was present. Biochemical analyses revealed that the LDH/Etf complex of A. woodii uses flavin-based electron confurcation to drive endergonic lactate oxidation with NAD(+) as oxidant at the expense of simultaneous exergonic electron flow from reduced ferredoxin (E0 ' ≈ -500 mV) to NAD(+) according to: lactate + Fd(2-)  + 2 NAD(+)  → pyruvate + Fd + 2 NADH. The reduced Fd(2-) is regenerated from NADH by a sequence of events that involves conversion of chemical (ATP) to electrochemical ( Δ μ ˜ Na + ) and finally redox energy (Fd(2-) from NADH) via reversed electron transport catalysed by the Rnf complex. Inspection of genomes revealed that this metabolic scenario for lactate oxidation may also apply to many other anaerobes. PMID:24762045

  20. Fermentative degradation of polyethylene glycol by a strictly anaerobic, gram-negative, nonsporeforming bacterium, Pelobacter venetianus sp. nov.

    PubMed

    Schink, B; Stieb, M

    1983-06-01

    The synthetic polyether polyethylene glycol (PEG) with a molecular weight of 20,000 was anaerobically degraded in enrichment cultures inoculated with mud of limnic and marine origins. Three strains (Gra PEG 1, Gra PEG 2, and Ko PEG 2) of rod-shaped, gram-negative, nonsporeforming, strictly anaerobic bacteria were isolated in mineral medium with PEG as the sole source of carbon and energy. All strains degraded dimers, oligomers, and polymers of PEG up to a molecular weight of 20,000 completely by fermentation to nearly equal amounts of acetate and ethanol. The monomer ethylene glycol was not degraded. An ethylene glycol-fermenting anaerobe (strain Gra EG 12) isolated from the same enrichments was identified as Acetobacterium woodii. The PEG-fermenting strains did not excrete extracellular depolymerizing enzymes and were inhibited by ethylene glycol, probably owing to a blocking of the cellular uptake system. PEG, some PEG-containing nonionic detergents, 1,2-propanediol, 1,2-butanediol, glycerol, and acetoin were the only growth substrates utilized of a broad variety of sugars, organic acids, and alcohols. The isolates did not reduce sulfate, sulfur, thiosulfate, or nitrate and were independent of growth factors. In coculture with A. woodii or Methanospirillum hungatei, PEGs and ethanol were completely fermented to acetate (and methane). A marine isolate is described as the type strain of a new species, Pelobacter venetianus sp. nov. Its physiology and ecological significance, as well as the importance and possible mechanism of anaerobic polyether degradation, are discussed. PMID:6881964

  1. Electrosynthesis of Organic Compounds from Carbon Dioxide Is Catalyzed by a Diversity of Acetogenic Microorganisms▿

    PubMed Central

    Nevin, Kelly P.; Hensley, Sarah A.; Franks, Ashley E.; Summers, Zarath M.; Ou, Jianhong; Woodard, Trevor L.; Snoeyenbos-West, Oona L.; Lovley, Derek R.

    2011-01-01

    Microbial electrosynthesis, a process in which microorganisms use electrons derived from electrodes to reduce carbon dioxide to multicarbon, extracellular organic compounds, is a potential strategy for capturing electrical energy in carbon-carbon bonds of readily stored and easily distributed products, such as transportation fuels. To date, only one organism, the acetogen Sporomusa ovata, has been shown to be capable of electrosynthesis. The purpose of this study was to determine if a wider range of microorganisms is capable of this process. Several other acetogenic bacteria, including two other Sporomusa species, Clostridium ljungdahlii, Clostridium aceticum, and Moorella thermoacetica, consumed current with the production of organic acids. In general acetate was the primary product, but 2-oxobutyrate and formate also were formed, with 2-oxobutyrate being the predominant identified product of electrosynthesis by C. aceticum. S. sphaeroides, C. ljungdahlii, and M. thermoacetica had high (>80%) efficiencies of electrons consumed and recovered in identified products. The acetogen Acetobacterium woodii was unable to consume current. These results expand the known range of microorganisms capable of electrosynthesis, providing multiple options for the further optimization of this process. PMID:21378039

  2. Influence of acidic pH on hydrogen and acetate production by an electrosynthetic microbiome

    SciTech Connect

    LaBelle, Edward V.; Marshall, Christopher W.; Gilbert, Jack A.; May, Harold D.; Battista, John R.

    2014-10-15

    Production of hydrogen and organic compounds by an electrosynthetic microbiome using electrodes and carbon dioxide as sole electron donor and carbon source, respectively, was examined after exposure to acidic pH (~5). Hydrogen production by biocathodes poised at -600 mV vs. SHE increased>100-fold and acetate production ceased at acidic pH, but ~5–15 mM (catholyte volume)/day acetate and>1,000 mM/day hydrogen were attained at pH ~6.5 following repeated exposure to acidic pH. Cyclic voltammetry revealed a 250 mV decrease in hydrogen overpotential and a maximum current density of 12.2 mA/cm2 at -765 mV (0.065 mA/cm2 sterile control at -800 mV) by the Acetobacterium-dominated community. Supplying -800 mV to the microbiome after repeated exposure to acidic pH resulted in up to 2.6 kg/m3/day hydrogen (≈2.6 gallons gasoline equivalent), 0.7 kg/m3/day formate, and 3.1 kg/m3/day acetate ( = 4.7 kg CO2 captured).

  3. Influence of acidic pH on hydrogen and acetate production by an electrosynthetic microbiome

    DOE PAGESBeta

    LaBelle, Edward V.; Marshall, Christopher W.; Gilbert, Jack A.; May, Harold D.; Battista, John R.

    2014-10-15

    Production of hydrogen and organic compounds by an electrosynthetic microbiome using electrodes and carbon dioxide as sole electron donor and carbon source, respectively, was examined after exposure to acidic pH (~5). Hydrogen production by biocathodes poised at -600 mV vs. SHE increased>100-fold and acetate production ceased at acidic pH, but ~5–15 mM (catholyte volume)/day acetate and>1,000 mM/day hydrogen were attained at pH ~6.5 following repeated exposure to acidic pH. Cyclic voltammetry revealed a 250 mV decrease in hydrogen overpotential and a maximum current density of 12.2 mA/cm2 at -765 mV (0.065 mA/cm2 sterile control at -800 mV) by the Acetobacterium-dominatedmore » community. Supplying -800 mV to the microbiome after repeated exposure to acidic pH resulted in up to 2.6 kg/m3/day hydrogen (≈2.6 gallons gasoline equivalent), 0.7 kg/m3/day formate, and 3.1 kg/m3/day acetate ( = 4.7 kg CO2 captured).« less

  4. Morphogenetic Mechanisms in the Cyclic Regeneration of Hair Follicles and Deer Antlers from Stem Cells

    PubMed Central

    Li, Chunyi; McMahon, Chris

    2013-01-01

    We have made comparisons between hair follicles (HFs) and antler units (AUs)—two seemingly unrelated mammalian organs. HFs are tiny and concealed within skin, whereas AUs are gigantic and grown externally for visual display. However, these two organs share some striking similarities. Both consist of permanent and cyclic/temporary components and undergo stem-cell-based organogenesis and cyclic regeneration. Stem cells of both organs reside in the permanent part and the growth centres are located in the temporary part of each respective organ. Organogenesis and regeneration of both organs depend on epithelial-mesenchymal interactions. Establishment of these interactions requires stem cells and reactive/niche cells (dermal papilla cells for HFs and epidermal cells for AUs) to be juxtaposed, which is achieved through destruction of the cyclic part to bring the reactive cells into close proximity to the respective stem cell niche. Developments of HFs and AUs are regulated by similar endocrine (particularly testosterone) and paracrine (particularly IGF1) factors. Interestingly, these two organs come to interplay during antlerogenesis. In conclusion, we believe that investigators from the fields of both HF and AU biology could greatly benefit from a comprehensive comparison between these two organs. PMID:24383056

  5. Improving Electrical Engineering Education at the American University of Sharjah through Continuous Assessment

    ERIC Educational Resources Information Center

    Al-Nashash, Hasan; Khaliq, Abdul; Qaddoumi, Nasser; Al-Assaf, Yousef; Assaleh, Khaled; Dhaouadi, Rached; El-Tarhuni, Mohamed

    2009-01-01

    The electrical engineering (ELE) program at the American University of Sharjah (AUS) is designed to fulfill the ABET criteria. Several assessment tools are used to qualitatively and quantitatively measure the level of achievement of the program's educational objectives and outcomes. These tools include alumni, employer, and graduate advisor…

  6. Population structure of the stable fly, Stomoxys calcitrans (L.) (Diptera: Muscidae) assessed on a global scale using Amplified Fragment Length Polymorphism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The stable fly, Stomoxys calcitrans (L.) (Diptera: Muscidae), is a major pest of livestock in the United States and worldwide. To assess the genetic variability in geographically distant stable flies, samples were obtained from four biogeographical regions: Nearctic, Neotropical, Palearctic, and Aus...

  7. Effect of microstructure on transformation-induced plasticity of silicon-containing low-alloy steel

    SciTech Connect

    Tomita, Yoshiyuki; Morioka, Kojiro

    1997-04-01

    Fe-0.6C-1.5Si-0.8Mn steel was studied to determine the effect of the microstructure on transformation-induced plasticity (TRIP) of silicon-containing low-alloy steel. A remarkable increase in elongation through TRIP can develop in the steel subjected to the following heat treatments: (1) austemper combined with subcritical annealing (SA Aus-T): subcritical annealing at 993K followed by austempering at 673K and then light tempering (after austenitization at 1173K); (2) austemper coupled with interrupted quenching (IQ Aus-T): interrupted quenching at 533K followed by austempering at 673K and light tempering (after austenization at 1,173K). The SA Aus-T treatment produced the triple structures of carbide-free upper bainite, retained austenite ({gamma}R), and free ferrite. As a result of the IQ Aus-T treatment, the triple structures of carbide-free upper bainite, {gamma}R, and tempered martensite appeared. The results are described and microstructural factors in TRIP are discussed.

  8. Geschichtliche Entwicklung der Abdichtungstechnik

    NASA Astrophysics Data System (ADS)

    Cziesielski, Erich

    Die Abdichtungstechnik mit industriell hergestellten Abdichtungsmaterialien ist relativ jung. Gleichwohl wurden aber auch schon im Altertum Bauwerke abgedichtet bzw. aus wasserundurchlässigem Beton (opus caementitium) hergestellt, wenn es darum ging, die erforderliche Wasserdichtigkeit im Bereich von Zisternen, Wasserleitungen, öffentlichen Bädern o.ä. zu erreichen.

  9. Physik im Beruf Physiker bei der Deutschen Börse

    NASA Astrophysics Data System (ADS)

    Schäfer, Carsten

    2002-01-01

    Seine wissenschaftlichen Wirkungsstätten sind schnell aufgezählt: Basel, St. Petersburg, Berlin. Und wieder St. Petersburg. Mit seiner Arbeit ist das schon schwieriger.Insgesamt zählt man ungefähr 900 Arbeiten und zwanzig Bücher aus seiner Feder.

  10. “Rice Diversity Panel”: A Genetic Resource for Exploring Phenotype-Genotype Associations in O. sativa.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A “Rice Diversity Panel” comprised of 409 purified rice (Oryza sativa L.) accessions originating from 79 countries was fingerprinted with 36 SSR markers, 1,536 SNP markers and more recently with a 44,100 SNP array. These accessions grouped into five ancestral subpopulations, indica, aus, tropical ja...

  11. Rice Root Architectural Plasticity Traits and Genetic Regions for Adaptability to Variable Cultivation and Stress Conditions.

    PubMed

    Sandhu, Nitika; Raman, K Anitha; Torres, Rolando O; Audebert, Alain; Dardou, Audrey; Kumar, Arvind; Henry, Amelia

    2016-08-01

    Future rice (Oryza sativa) crops will likely experience a range of growth conditions, and root architectural plasticity will be an important characteristic to confer adaptability across variable environments. In this study, the relationship between root architectural plasticity and adaptability (i.e. yield stability) was evaluated in two traditional × improved rice populations (Aus 276 × MTU1010 and Kali Aus × MTU1010). Forty contrasting genotypes were grown in direct-seeded upland and transplanted lowland conditions with drought and drought + rewatered stress treatments in lysimeter and field studies and a low-phosphorus stress treatment in a Rhizoscope study. Relationships among root architectural plasticity for root dry weight, root length density, and percentage lateral roots with yield stability were identified. Selected genotypes that showed high yield stability also showed a high degree of root plasticity in response to both drought and low phosphorus. The two populations varied in the soil depth effect on root architectural plasticity traits, none of which resulted in reduced grain yield. Root architectural plasticity traits were related to 13 (Aus 276 population) and 21 (Kali Aus population) genetic loci, which were contributed by both the traditional donor parents and MTU1010. Three genomic loci were identified as hot spots with multiple root architectural plasticity traits in both populations, and one locus for both root architectural plasticity and grain yield was detected. These results suggest an important role of root architectural plasticity across future rice crop conditions and provide a starting point for marker-assisted selection for plasticity. PMID:27342311

  12. Offshore Teaching Practice in the Australia-Pacific Technical College: A Case Study in the South Pacific

    ERIC Educational Resources Information Center

    Bailey, Anthony

    2011-01-01

    This paper investigates teaching practices at the Australia-Pacific Technical College (APTC), which comprise a unique official development assistance (ODA) program funded by the Government of Australia (GoA) and managed through the Australian Agency for International Development (AusAid) with the aim of training and equipping workers from the…

  13. Learning to Lead: A Social Justice Perspective on Understanding Elementary Teacher Leadership in Papua New Guinea

    ERIC Educational Resources Information Center

    Brownlee, Joanne; Scholes, Laura; Farrell, Ann; Davis, Julie; Cook, Donna

    2012-01-01

    Leadership in elementary education is currently recognized as a political imperative in Papua New Guinea (PNG), as the nation develops strategies towards equitable access to schooling. One recent initiative aimed at building educational leadership was an intensive Australian Leadership Award Fellowship (ALAF) program funded by AusAID, involving a…

  14. Attention Deficit Hyperactivity Disorder in Preschool Aged Children. Clinical Approaches to Early Intervention in Child and Adolescent Mental Health, Volume 1.

    ERIC Educational Resources Information Center

    Hazell, Philip

    The need for guidelines for early intervention of children experiencing Attention Deficit Hyperactivity Disorders (ADHD) was identified by the Australian Early Intervention Network (AusEinet). This document attempts to guide appropriate practice in the care of children and adolescents with ADHD. The guidelines are designed to provide information…

  15. Physik gestern und heute: Visualisierung mit der Schlierenmethode

    NASA Astrophysics Data System (ADS)

    Heering, Peter

    2006-07-01

    Der Name des österreichischen Forschers Ernst Mach ist heute noch mit der Schallgeschwindigkeit verbunden. Diese Auszeichnung resultiert aus Machs Untersuchungen, wie sich Projektile mit Überschallgeschwindigkeit durch die Luft bewegen. Gerade in jüngster Zeit hat die Anwendung derartiger Methoden durch technische Modifikationen wieder einen Aufschwung erfahren.

  16. Investigating the Impacts of Global Education Curriculum on the Values and Attitudes of Secondary Students

    ERIC Educational Resources Information Center

    DeNobile, John; Kleeman, Grant; Zarkos, Anastasia

    2014-01-01

    Each year, World Vision and AusAID devote substantial resources to their educational programs. These initiatives include the production and dissemination of Global Education related instructional materials and the provision of professional learning for teachers. Given the substantial funds involved, it is important that we evaluate the…

  17. 22 CFR 126.16 - Exemption pursuant to the Defense Trade Cooperation Treaty between the United States and Australia.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Explosives found at 27 CFR parts 447, 478, and 479, which are unaffected by the Defense Trade Cooperation... and USA Treaty Community//.” For example, for defense articles classified SECRET, the marking or identification shall be “//SECRET USML//REL AUS and USA Treaty Community//.” (ii) Unclassified defense...

  18. Unraveling the rich phenotypic and genetic diversity in rice for varietal improvement

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Asian cultivated rice (Oryza sativa L.) has two distinct varietal groups identified as the indica and japonica subspecies. With the advent of molecular markers the indica subspecies was divided into the indica and aus subpopulation groups and the japonica subspecies into the aromatic, tropical japon...

  19. Unraveling the rich phenotypic and genetic diversity in rice for varietal improvement

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Asian cultivated rice (Oryza sativa L.) has two distinct varietal groups identified as the indica and japonica subspecies. With the advent of molecular markers the indica subspecies was divided into the indica and aus subpopulation groups and the japonica subspecies into the aromatic, tropical japo...

  20. Kapselung sicherheitskritischer Funktionen in automobilen Steuergeräten

    NASA Astrophysics Data System (ADS)

    Eberhard, Denis

    Die Kapselung von Software-Teilen von Fahrzeug-Software sicherheitskritischer Systeme ist derzeit nicht üblich. Es werden die Grundlagen der Kapslung beschrieben und abgegrenzt. Exemplarisch wird Speicherschutz hinsichtlich Anforderungen, Autosar-Spezifikationen und Anwendung untersucht. Aus den Unterschieden der Theorie von Kapselung und aktuellen Spezifikation lassen sich Spezifikationslücken bzw. Verbesserungspotentiale für Autosar ableiten.

  1. On Sources of the Word Length Effect in Young Readers

    ERIC Educational Resources Information Center

    Gagl, Benjamin; Hawelka, Stefan; Wimmer, Heinz

    2015-01-01

    We investigated how letter length, phoneme length, and consonant clusters contribute to the word length effect in 2nd- and 4th-grade children. They read words from three different conditions: In one condition, letter length increased but phoneme length did not due to multiletter graphemes (H"aus"-B"auch"-S"chach"). In…

  2. Katzenaugen und Sternsteine: Spielwiese

    NASA Astrophysics Data System (ADS)

    Ucke, Christian; Schlichting, Hans-Joachim

    2004-07-01

    Edelsteine vom Typ Chrysoberyll sind auch unter der Kurzbezeichnung Katzenauge bekannt. Im Chrysoberyll eingelagert sind feine, parallel angeordnete, metallisch glänzende Nadeln aus Rutil (Titandioxid). Auch Hohlkanäle und Risse durchziehen das Material. Lichtreflexion an diesen Einlagerungen und Kanälen erklärt das Lichtband, das dem Stein zu seinem Namen verhalf.

  3. Spanish is better than English for discriminating Portuguese vowels: acoustic similarity versus vowel inventory size

    PubMed Central

    Elvin, Jaydene; Escudero, Paola; Vasiliev, Polina

    2014-01-01

    Second language (L2) learners often struggle to distinguish sound contrasts that are not present in their native language (L1). Models of non-native and L2 sound perception claim that perceptual similarity between L1 and L2 sound contrasts correctly predicts discrimination by naïve listeners and L2 learners. The present study tested the explanatory power of vowel inventory size versus acoustic properties as predictors of discrimination accuracy when naïve Australian English (AusE) and Iberian Spanish (IS) listeners are presented with six Brazilian Portuguese (BP) vowel contrasts. Our results show that IS listeners outperformed AusE listeners, confirming that cross-linguistic acoustic properties, rather than cross-linguistic vowel inventory sizes, successfully predict non-native discrimination difficulty. Furthermore, acoustic distance between BP vowels and closest L1 vowels successfully predicted differential levels of difficulty among the six BP contrasts, with BP /e-i/ and /o-u/ being the most difficult for both listener groups. We discuss the importance of our findings for the adequacy of models of L2 speech perception. PMID:25400599

  4. A “Rice Diversity Panel” evaluated for genetic and agro-morphological variation between subpopulations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since ancient times, Indica and Japonica have been recognized as the two major subspecies of Asian rice (Oryza sativa L.). First with isozymes and subsequently with DNA markers, five subpopulations indica, aus, temperate japonica, tropical japonica and aromatic/GroupV were identified. A “Rice Diver...

  5. Genetic structural analysis for germplasm accessions in the USDA Rice World Collection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice is grouped into five genetic structures including indica, aus, aromatic, temperate japonica, and tropical japonica. A core collection having 1,785 accessions from 114 countries has been developed that is representative of the USDA rice world collection which includes over 18,000 accessions. The...

  6. MICROBIOLOGICAL CHARACTERIZATION OF IMPORTED AND DOMESTIC BONELESS BEEF TRIM USED FOR GROUND BEEF

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The United States imports lean boneless beef trim from Australia (AUS), New Zealand (NZL), and Uruguay (URY) to meet demand for ground beef production. The reported incidence of, and etiological agents responsible for, foodborne disease differ between these countries and the United States. Therefo...

  7. Incorporating Computer-Aided Software in the Undergraduate Chemical Engineering Core Courses

    ERIC Educational Resources Information Center

    Alnaizy, Raafat; Abdel-Jabbar, Nabil; Ibrahim, Taleb H.; Husseini, Ghaleb A.

    2014-01-01

    Introductions of computer-aided software and simulators are implemented during the sophomore-year of the chemical engineering (ChE) curriculum at the American University of Sharjah (AUS). Our faculty concurs that software integration within the curriculum is beneficial to our students, as evidenced by the positive feedback received from industry…

  8. Praktikerporträts

    NASA Astrophysics Data System (ADS)

    Herber, Kamilla; Kramer, Regine; Voigt, Bernd

    Wie vielfältig die beruflichen Möglichkeiten von MINT-Absolventen sind, zeigen die nachfolgenden Praktikerporträts. Aus sämtlichen Branchen und in den verschiedensten Positionen berichten die Praktiker über ihr Studium, die unterschiedlichsten Karrierewege und ihre Erfahrungen im Berufsleben.

  9. Curriculum Development for Teacher Education in the Southern Philippines: A Simultaneous Process of Professional Learning and Syllabus Enhancement

    ERIC Educational Resources Information Center

    Zeegers, Yvonne

    2012-01-01

    This paper reflects on the process of curriculum development in 21 tertiary education institutions in the Southern Philippines. Assisting capacity-building of the teaching profession is an ongoing need in developing countries, but rarely does it extend to pre-service education. In this study of one aspect of a three year AusAid-funded education…

  10. Die Evolution der Religiosität

    NASA Astrophysics Data System (ADS)

    Voland, Eckart

    Ein konsequent darwinischer Blick auf den Menschen bedeutet, auch im Denken, Fühlen und Handeln biologische Anpassungsgeschichte zu suchen, denn auch die psychischen und mentalen Eigenheiten des Homo sapiens unterliegen der natürlichen Selektion. Lässt sich die religiöse Lebenspraxis von Menschen daher auch aus einer Fitnessperspektive betrachten?

  11. An Investigation of the Teacher Advancement Program and Student Performance in Urban Schools

    ERIC Educational Resources Information Center

    Grant, Ginger Madonna

    2010-01-01

    In 2005, the achievement gap between African-American and Caucasian students doubled in the state of Louisiana. Sixty-three percent of the public schools in an urban school district in southeastern Louisiana received an Academically Unacceptable Status (AUS) rating according to Louisiana accountability standards. In 2006, the Louisiana Board of…

  12. New GO-PEI-Au-L-Cys ZIC-HILIC composites: synthesis and selective enrichment of glycopeptides.

    PubMed

    Jiang, Bo; Liang, Yu; Wu, Qi; Jiang, Hao; Yang, Kaiguang; Zhang, Lihua; Liang, Zhen; Peng, Xiaojun; Zhang, Yukui

    2014-06-01

    GO-PEI-Au-L-Cys composites were synthesized via loading gold nanoparticles on a GO surface using polyethylenimine as reducing and stabilizing reagents, followed by L-cysteine immobilization through an Au-S bond. The composites were applied as a kind of novel ZIC-HILIC material to achieve highly selective enrichment of glycopeptides from biological samples. PMID:24752239

  13. Unlocking the variation hidden in rice germplasm collections with genomics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cultivated Asian rice (Oryza sativa) was domesticated from O. rufipogon (O. nivara). The O. sativa subspecies indica and japonica diverged in ancient times, and based on DNA markers, further subdivided into the five major subpopulations, aus, indica, aromatic, tropical japonica and temperate japoni...

  14. Differences between Children and Adults in the Recognition of Enjoyment Smiles

    ERIC Educational Resources Information Center

    Del Giudice, Marco; Colle, Livia

    2007-01-01

    The authors investigated the differences between 8-year-olds (n = 80) and adults (n = 80) in recognition of felt versus faked enjoyment smiles by using a newly developed picture set that is based on the Facial Action Coding System. The authors tested the effect of different facial action units (AUs) on judgments of smile authenticity. Multiple…

  15. Crystals: The Love Child Born from Art and Science

    ERIC Educational Resources Information Center

    Leong, Noby

    2014-01-01

    Noby Leong is a PhD student in Chemistry at University of Adelaide working on the design of new drug delivery systems for medical applications. He's also a science communicator, part of the volunteer blogging community at RiAus and curator of his own blog "The Other Side of Science." In this article Noby shares the highs and lows…

  16. Auf der Suche nach extrasolaren Transitplaneten

    NASA Astrophysics Data System (ADS)

    Heller, René

    2010-06-01

    Planeten um andere Sonnen, die von der Erde aus gesehen einmal während ihres Orbits vor ihrem Zentralstern vorbeiziehen, eröffnen eine bis vor Kurzem ungeahnte Palette an Möglichkeiten zu ihrer Untersuchung. Nur: Wo am Himmel lassen sich diese Kandidaten für Sternbedeckungen eigentlich finden?

  17. Molekularbiologische Speziesdifferenzierung

    NASA Astrophysics Data System (ADS)

    Mäde, Dietrich

    Der Speziesnachweis in Lebensmitteln dient der Analyse, aus welchen Tier- und Pflanzenarten die Erzeugnisse hergestellt wurden. Die Information darüber ist sowohl für den Gesundheitsschutz als auch für den Schutz vor Täuschungspraktiken und zur Information des Verbrauchers wichtig.

  18. Geographic description of genetic diversity and genetic relationships in the USDA Rice World Collection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Asian cultivated rice (Oryza sativa L.) is structured into five genetic groups, indica, AUS, tropical japonica, temperate japonica and aromatic. Genetic characterization of a global rice collection could help better serve the global research community. Collecting worldwide rice germplasm started in ...

  19. Rice Root Architectural Plasticity Traits and Genetic Regions for Adaptability to Variable Cultivation and Stress Conditions1[OPEN

    PubMed Central

    Sandhu, Nitika; Raman, K. Anitha; Torres, Rolando O.; Audebert, Alain; Dardou, Audrey; Kumar, Arvind; Henry, Amelia

    2016-01-01

    Future rice (Oryza sativa) crops will likely experience a range of growth conditions, and root architectural plasticity will be an important characteristic to confer adaptability across variable environments. In this study, the relationship between root architectural plasticity and adaptability (i.e. yield stability) was evaluated in two traditional × improved rice populations (Aus 276 × MTU1010 and Kali Aus × MTU1010). Forty contrasting genotypes were grown in direct-seeded upland and transplanted lowland conditions with drought and drought + rewatered stress treatments in lysimeter and field studies and a low-phosphorus stress treatment in a Rhizoscope study. Relationships among root architectural plasticity for root dry weight, root length density, and percentage lateral roots with yield stability were identified. Selected genotypes that showed high yield stability also showed a high degree of root plasticity in response to both drought and low phosphorus. The two populations varied in the soil depth effect on root architectural plasticity traits, none of which resulted in reduced grain yield. Root architectural plasticity traits were related to 13 (Aus 276 population) and 21 (Kali Aus population) genetic loci, which were contributed by both the traditional donor parents and MTU1010. Three genomic loci were identified as hot spots with multiple root architectural plasticity traits in both populations, and one locus for both root architectural plasticity and grain yield was detected. These results suggest an important role of root architectural plasticity across future rice crop conditions and provide a starting point for marker-assisted selection for plasticity. PMID:27342311

  20. Mol-Gastronomie Granulare Fleischgerichte und molekulares Kleben

    NASA Astrophysics Data System (ADS)

    Vilgis, Thomas A.

    2005-09-01

    Buletten, Fleischküchle oder Kebabs, Köstlichkeiten aus gehacktem Fleisch bestimmter Körnung, finden sich in allen Kulturen. Physikalisch ein großes Problem, denn zu Tisch dürfen diese Gebilde nicht auseinander brechen und zerfallen. Für ausreichend Bindung und Klebung muss also gesorgt werden.

  1. Rowing the Weaves of Community Participation: Good Practices in Early Childhood Development (ECD) Program in Rural Central Lombok, West Nusa Tenggara

    ERIC Educational Resources Information Center

    Abdillah, Ali

    2014-01-01

    This paper describes the rural community participation within the context of an integrated early childhood development program initiated by the government of Indonesia in partnership with UNICEF and AusAID in Central Lombok (2008-2010). Based on purposive interviews with relevant stakeholders, as well as an analysis of past documents,…

  2. Magnus Strandqvist: 50th anniversary of his doctoral thesis.

    PubMed

    Kajanti, M J

    1994-01-01

    This article is dedicated to Magnus Strandqvist's famous doctoral thesis "Studien über die kumulative Wirkung der Röntgenstrahlen bei Fraktionierung. Erfahrungen aus dem Radiumhemmet an 280 Haut- und Lippenkarzinomen" published in Acta Radiologica in 1944. After a short biography of Strandqvist some central points of his work and their influence on future development of modern radiotherapy are presented. PMID:7993639

  3. Finite-precision arithmetic in singular-value decomposition architectures

    SciTech Connect

    Duryea, R.A.

    1987-01-01

    The singular-value decomposition (SVD) is an important matrix algorithm that has many applications in signal processing. However, its use has been limited due to its computational complexity. Several architecture have been proposed to compute the SVD using arrays of parallel processors. This thesis derives requirements for the precision of arithmetic units (AUs) used in SVD arrays and compares the resource requirements of several architectures. The author's results are based on the assumption that he is operating on matrices of quantized data. Since the matrices have quantization errors, he shows that their singular values will have quantization errors as large as the data errors. To compute the number of bits needed in SVD AUs, it is required that the AUs have enough bits to keep the round-off errors of the SVD computation smaller than the quantization errors. The analysis shows that we need essentially the same number of bits for either the Hestenes of Jacobi SVD algorithms. Five SVD architectures, two linear structures and three quadratic arrays are described and their resource requirements are compared with floating point and CORDIC AUs. The comparison shows the total resource requirements of the linear designs to be lower than that of the quadratic arrays for all-size matrices.

  4. Computerunterstütztes Modellieren mit Musiknetzen

    NASA Astrophysics Data System (ADS)

    Levens, Ulla

    In der folgenden Ausführung geht es um eine Anwendung von Petri-Netzen im Bereich Musik. Ausgehend von der Implementierung einer speziellen Anwendung, dem Programmsystem ScoreSynth, wird das zugrundeliegende Konzept erläutert und anschließend an einem kleinen Beispiel veranschaulicht. Dieser Beitrag ist ein Auszug aus [Lev95b].

  5. Improved digital breast tomosynthesis images using automated ultrasound

    PubMed Central

    Zhang, Xing; Yuan, Jie; Du, Sidan; Kripfgans, Oliver D.; Wang, Xueding; Carson, Paul L.; Liu, Xiaojun

    2014-01-01

    Purpose: Digital breast tomosynthesis (DBT) offers poor image quality along the depth direction. This paper presents a new method that improves the image quality of DBT considerably through the a priori information from automated ultrasound (AUS) images. Methods: DBT and AUS images of a complex breast-mimicking phantom are acquired by a DBT/AUS dual-modality system. The AUS images are taken in the same geometry as the DBT images and the gradient information of the in-slice AUS images is adopted into the new loss functional during the DBT reconstruction process. The additional data allow for new iterative equations through solving the optimization problem utilizing the gradient descent method. Both visual comparison and quantitative analysis are employed to evaluate the improvement on DBT images. Normalized line profiles of lesions are obtained to compare the edges of the DBT and AUS-corrected DBT images. Additionally, image quality metrics such as signal difference to noise ratio (SDNR) and artifact spread function (ASF) are calculated to quantify the effectiveness of the proposed method. Results: In traditional DBT image reconstructions, serious artifacts can be found along the depth direction (Z direction), resulting in the blurring of lesion edges in the off-focus planes parallel to the detector. However, by applying the proposed method, the quality of the reconstructed DBT images is greatly improved. Visually, the AUS-corrected DBT images have much clearer borders in both in-focus and off-focus planes, fewer Z direction artifacts and reduced overlapping effect compared to the conventional DBT images. Quantitatively, the corrected DBT images have better ASF, indicating a great reduction in Z direction artifacts as well as better Z resolution. The sharper line profiles along the Y direction show enhancement on the edges. Besides, noise is also reduced, evidenced by the obviously improved SDNR values. Conclusions: The proposed method provides great improvement on

  6. U.S. Geological Survey 2013 assessment of undiscovered resources in the Bakken and Three Forks Formations of the U.S. Williston Basin Province

    USGS Publications Warehouse

    Gaswirth, Stephanie B.; Marra, Kristen R.

    2014-01-01

    The Upper Devonian Three Forks and Upper Devonian to Lower Mississippian Bakken Formations comprise a major United States continuous oil resource. Current exploitation of oil is from horizontal drilling and hydraulic fracturing of the Middle Member of the Bakken and upper Three Forks, with ongoing exploration of the lower Three Forks, and the Upper, Lower, and Pronghorn Members of the Bakken Formation. In 2008, the U.S. Geological Survey (USGS) estimated a mean of 3.65 billion bbl of undiscovered, technically recoverable oil resource within the Bakken Formation. The USGS recently reassessed the Bakken Formation, which included an assessment of the underlying Three Forks Formation. The Pronghorn Member of the Bakken Formation, where present, was included as part of the Three Forks assessment due to probable fluid communication between reservoirs. For the Bakken Formation, five continuous and one conventional assessment units (AUs) were defined. These AUs are modified from the 2008 AU boundaries to incorporate expanded geologic and production information. The Three Forks Formation was defined with one continuous and one conventional AU. Within the continuous AUs, optimal regions of hydrocarbon recovery, or “sweet spots,” were delineated and estimated ultimate recoveries were calculated for each continuous AU. Resulting undiscovered, technically recoverable resource estimates were 3.65 billion bbl for the five Bakken continuous oil AUs and 3.73 billion bbl for the Three Forks Continuous Oil AU, generating a total mean resource estimate of 7.38 billion bbl. The two conventional AUs are hypothetical and represent a negligible component of the total estimated resource (8 million barrels of oil).

  7. Phylogenetically Novel LuxI/LuxR-Type Quorum Sensing Systems Isolated Using a Metagenomic Approach

    PubMed Central

    Nasuno, Eri; Fujita, Masaki J.; Nakatsu, Cindy H.; Kamagata, Yoichi; Hanada, Satoshi

    2012-01-01

    A great deal of research has been done to understand bacterial cell-to-cell signaling systems, but there is still a large gap in our current knowledge because the majority of microorganisms in natural environments do not have cultivated representatives. Metagenomics is one approach to identify novel quorum sensing (QS) systems from uncultured bacteria in environmental samples. In this study, fosmid metagenomic libraries were constructed from a forest soil and an activated sludge from a coke plant, and the target genes were detected using a green fluorescent protein (GFP)-based Escherichia coli biosensor strain whose fluorescence was screened by spectrophotometry. DNA sequence analysis revealed two pairs of new LuxI family N-acyl-l-homoserine lactone (AHL) synthases and LuxR family transcriptional regulators (clones N16 and N52, designated AubI/AubR and AusI/AusR, respectively). AubI and AusI each produced an identical AHL, N-dodecanoyl-l-homoserine lactone (C12-HSL), as determined by nuclear magnetic resonance (NMR) and mass spectrometry. Phylogenetic analysis based on amino acid sequences suggested that AusI/AusR was from an uncultured member of the Betaproteobacteria and AubI/AubR was very deeply branched from previously described LuxI/LuxR homologues in isolates of the Proteobacteria. The phylogenetic position of AubI/AubR indicates that they represent a QS system not acquired recently from the Proteobacteria by horizontal gene transfer but share a more ancient ancestry. We demonstrated that metagenomic screening is useful to provide further insight into the phylogenetic diversity of bacterial QS systems by describing two new LuxI/LuxR-type QS systems from uncultured bacteria. PMID:22983963

  8. Systematics and phylogenetics of Indo-Pacific Luciolinae fireflies (Coleoptera: Lampyridae) and the description of new genera.

    PubMed

    Ballantyne, Lesly A; Lambkin, Christine L

    2013-01-01

    presented for the males and females. Certain females are characterised by the nature of their bursa plates. Australoluciola gen. nov. is proposed for ten species from Australia and New Guinea, seven transferred from Luciola and three new, with species keyed from males, all of which have an entire light organ in ventrite 7. Aus. anthracina (Olivier), Aus. aspera (Olivier), Aus. australis (F.), Aus. flavicollis (MacLeay), Aus. foveicollis (Olivier), Aus. nigra (Olivier) and Aus. orapallida (Ballantyne) are transferred from Luciola with males assigned to Aus. aspera(Olivier), and a lectotype designated for Luciola foveicollis Olivier; Aus. baduria sp. nov., Aus. fuscamagna sp. nov.,Aus. fuscaparva sp. nov., Aus. japenensis sp. nov. and Aus. pharusaurea sp. nov. are described. Females of Aus. australis and Aus. flavicollis have two pairs of wide bursa plates.  The bent-winged fireflies of New Guinea and Australia are removed from Pteroptyx Olivier and assigned to Medeopteryx gen. nov. and Trisinuata gen. nov. Medeopteryx gen. nov. is erected for 17 species including two new; all have ventrite 7 with an entire light organ, trisinuate posterior margin and short posterolateral projections; the following 14 species in which males have deflexed elytral apices are transferred from Pteroptyx Olivier: M. amilae (Satô), M. antennata (Olivier), M. corusca (Ballantyne), M. cribellata (Olivier), M. effulgens (Ballantyne), M. elucens (Ballantyne), M. flagrans (Ballantyne), M. fulminea (Ballantyne), M. hanedai (Ballantyne), M. platygaster (Lea), M. similisantennata(Ballantyne), M. sublustris (Ballantyne), M. tarsalis (Olivier), and M. torricelliensis (Ballantyne). M. clipeata sp. nov. is described. Two species without deflexed elytral apices include M. pupilla (Olivier) which is transferred from Luciola, and M. similispupillae sp. nov. A Lectotype is designated for Luciola pupilla (Olivier). Females of M. corusca(Ballantyne), M. cribellata (Olivier), M. effulgens (Ballantyne), and M

  9. Anaerobic Biodegradation of Ethylene Glycol within Hydraulic Fracturing Fluid

    NASA Astrophysics Data System (ADS)

    Heyob, K. M.; Mouser, P. J.

    2014-12-01

    Ethylene glycol (EG) is a commonly used organic additive in hydraulic fracturing fluids used for shale gas recovery. Under aerobic conditions, this compound readily biodegrades to acetate and CO2 or is oxidized through the glycerate pathway. In the absence of oxygen, organisms within genera Desulfovibrio, Acetobacterium, and others can transform EG to acetaldehyde, a flammable and suspected carcinogenic compound. Acetaldehyde can then be enzymatically degraded to ethanol or acetate and CO2. However, little is known on how EG degrades in the presence of other organic additives, particularly under anaerobic conditions representative of deep groundwater aquifers. To better understand the fate and attenuation of glycols within hydraulic fracturing fluids we are assessing their biodegradation potential and pathways in batch anaerobic microcosm treatments. Crushed Berea sandstone was inoculated with groundwater and incubated with either EG or a synthetic fracturing fluid (SFF) containing EG formulations. We tracked changes in dissolved organic carbon (DOC), EG, and its transformation products over several months. Approximately 41% of bulk DOC in SFF is degraded within 21 days, with 58% DOC still remaining after 63 days. By comparison, this same SFF degrades by 70% within 25 days when inoculated with sediment-groundwater microbial communities, suggesting that bulk DOC degradation occurs at a slower rate and to a lesser extent with bedrock. Aerobic biodegradation of EG occurs rapidly (3-7 days); however anaerobic degradation of EG is much slower, requiring several weeks for substantial DOC loss to be observed. Ongoing experiments are tracking the degradation pathways of EG alone and in the presence of SFF, with preliminary data showing incomplete glycol transformation within the complex hydraulic fracturing fluid mixture. This research will help to elucidate rates, processes, and pathways for EG biodegradation and identify key microbial taxa involved in its degradation.

  10. Characterization of an O-Demethylase of Desulfitobacterium hafniense DCB-2

    PubMed Central

    Studenik, Sandra; Vogel, Michaela

    2012-01-01

    Besides acetogenic bacteria, only Desulfitobacterium has been described to utilize and cleave phenyl methyl ethers under anoxic conditions; however, no ether-cleaving O-demethylases from the latter organisms have been identified and investigated so far. In this study, genes of an operon encoding O-demethylase components of Desulfitobacterium hafniense strain DCB-2 were cloned and heterologously expressed in Escherichia coli. Methyltransferases I and II were characterized. Methyltransferase I mediated the ether cleavage and the transfer of the methyl group to the superreduced corrinoid of a corrinoid protein. Desulfitobacterium methyltransferase I had 66% identity (80% similarity) to that of the vanillate-demethylating methyltransferase I (OdmB) of Acetobacterium dehalogenans. The substrate spectrum was also similar to that of the latter enzyme; however, Desulfitobacterium methyltransferase I showed a higher level of activity for guaiacol and used methyl chloride as a substrate. Methyltransferase II catalyzed the transfer of the methyl group from the methylated corrinoid protein to tetrahydrofolate. It also showed a high identity (∼70%) to methyltransferases II of A. dehalogenans. The corrinoid protein was produced in E. coli as cofactor-free apoprotein that could be reconstituted with hydroxocobalamin or methylcobalamin to function in the methyltransferase I and II assays. Six COG3894 proteins, which were assumed to function as activating enzymes mediating the reduction of the corrinoid protein after an inadvertent oxidation of the corrinoid cofactor, were studied with respect to their abilities to reduce the recombinant reconstituted corrinoid protein. Of these six proteins, only one was found to catalyze the reduction of the corrinoid protein. PMID:22522902

  11. Isolation of Acetogenic Bacteria That Induce Biocorrosion by Utilizing Metallic Iron as the Sole Electron Donor

    PubMed Central

    Yumoto, Isao; Kamagata, Yoichi

    2014-01-01

    Corrosion of iron occurring under anoxic conditions, which is termed microbiologically influenced corrosion (MIC) or biocorrosion, is mostly caused by microbial activities. Microbial activity that enhances corrosion via uptake of electrons from metallic iron [Fe(0)] has been regarded as one of the major causative factors. In addition to sulfate-reducing bacteria and methanogenic archaea in marine environments, acetogenic bacteria in freshwater environments have recently been suggested to cause MIC under anoxic conditions. However, no microorganisms that perform acetogenesis-dependent MIC have been isolated or had their MIC-inducing mechanisms characterized. Here, we enriched and isolated acetogenic bacteria that induce iron corrosion by utilizing Fe(0) as the sole electron donor under freshwater, sulfate-free, and anoxic conditions. The enriched communities produced significantly larger amounts of Fe(II) than the abiotic controls and produced acetate coupled with Fe(0) oxidation prior to CH4 production. Microbial community analysis revealed that Sporomusa sp. and Desulfovibrio sp. dominated in the enrichments. Strain GT1, which is closely related to the acetogen Sporomusa sphaeroides, was eventually isolated from the enrichment. Strain GT1 grew acetogenetically with Fe(0) as the sole electron donor and enhanced iron corrosion, which is the first demonstration of MIC mediated by a pure culture of an acetogen. Other well-known acetogenic bacteria, including Sporomusa ovata and Acetobacterium spp., did not grow well on Fe(0). These results indicate that very few species of acetogens have specific mechanisms to efficiently utilize cathodic electrons derived from Fe(0) oxidation and induce iron corrosion. PMID:25304512

  12. Comparison of electrochemical and microbiological characterization of microbial fuel cells equipped with SPEEK and Nafion membrane electrode assemblies.

    PubMed

    Suzuki, Kei; Owen, Rubaba; Mok, Joann; Mochihara, Hiroki; Hosokawa, Takuya; Kubota, Hiroko; Sakamoto, Hisatoshi; Matsuda, Atsunori; Tashiro, Yosuke; Futamata, Hiroyuki

    2016-09-01

    Microbial fuel cells equipped with SPEEK-MEA (SPEEK-MFC) and Nafion-MEA (Nafion-MFC) were constructed with organic waste as electron donor and lake sediment as inoculum and were then evaluated comprehensively by electrochemical and microbial analyses. The proton conductivity of SPEEK was several hundreds-fold lower than that of Nafion 117, whereas the oxygen mass and diffusion transfer coefficients of SPEEK were 10-fold lower than those of Nafion 117. It was difficult to predict which was better membrane for MFC based on the feature of membrane. Analyses of polarization curves indicated that the potential of electricity production was similar in both MFCs, as the SPEEK-MFC produced 50-80% of the practical current density generated by the Nafion-MFC. Chronopotentiometry analyses indicated that the Nafion-MEA kept the performance longer than the SPEEK-MEA for long period, whereas performance of both anodes improved on time. Multidimensional scaling analyses based on DGGE profiles revealed the anolytic and biofilm communities of the SPEEK-MFC had developed differently from those of the Nafion-MFC. Clone library analyses indicated that Geobacter spp. represented 6.3% of the biofilm bacterial community in the Nafion-MFC but not detected in the SPEEK-MFC. Interestingly, the clone closely related to Acetobacterium malicum strain HAAP-1, belonging to the homoacetogens, became dominant in both anolytic and biofilm communities of the SPEEK-MFC. It was suggested that the lower proton conductivity of SPEEK-MEA allowed the bacteria closely related to strain HAAP-1 to be dominant specifically in SPEEK-MFC. These results indicated that Nafion-MFC ranked with SPEEK-MFC and that MEAs had strong selective pressure for electricity-producing bacterial community. PMID:27215833

  13. Long-term operation of microbial electrosynthesis systems improves acetate production by autotrophic microbiomes.

    PubMed

    Marshall, Christopher W; Ross, Daniel E; Fichot, Erin B; Norman, R Sean; May, Harold D

    2013-06-01

    Microbial electrosynthesis is the biocathode-driven production of chemicals from CO2 and has the promise to be a sustainable, carbon-consuming technology. To date, microbial electrosynthesis of acetate, the first step in order to generate liquid fuels from CO2, has been characterized by low rates and yields. To improve performance, a previously established acetogenic biocathode was operated in semi-batch mode at a poised potential of -590 mV vs SHE for over 150 days beyond its initial development. Rates of acetate production reached a maximum of 17.25 mM day(-1) (1.04 g L(-1) d(-1)) with accumulation to 175 mM (10.5 g L(-1)) over 20 days. Hydrogen was also produced at high rates by the biocathode, reaching 100 mM d(-1) (0.2 g L(-1) d(-1)) and a total accumulation of 1164 mM (2.4 g L(-1)) over 20 days. Phylogenetic analysis of the active electrosynthetic microbiome revealed a similar community structure to what was observed during an earlier stage of development of the electroacetogenic microbiome. Acetobacterium spp. dominated the active microbial population on the cathodes. Also prevalent were Sulfurospirillum spp. and an unclassified Rhodobacteraceae. Taken together, these results demonstrate the stability, resilience, and improved performance of electrosynthetic biocathodes following long-term operation. Furthermore, sustained product formation at faster rates by a carbon-capturing microbiome is a key milestone addressed in this study that advances microbial electrosynthesis systems toward commercialization. PMID:23676111

  14. Bacterial Community Profiling of H2/CO2 or Formate-Utilizing Acetogens Enriched from Diverse Ecosystems

    NASA Astrophysics Data System (ADS)

    Han, R.; Zhang, L.; Fu, B.; Liu, H.

    2014-12-01

    Synthetic gases are usually generated from either cellulosic agricultural waste combustion or industrial release and could be subsequently transformed into acetate, ethanol, and/or butyrate by homoacetogenic bacteria, which commonly possess reductive acetyl-CoA synthesis pathway. Homoacetogen-based syngas fermentation technology provides an alternative solution to link greenhouse gas emission control and cellulosic solid waste treatment with biofuels production. The objective of our current project is to hunt for homoacetogens with capabilities of highly efficiently converting syngases to chemical solvents. In this study, we evaluated homoacetogens population dynamics during enrichments and pinpointed dominant homoacetogens representing diverse ecosystems enriched by different substrates. We enriched homoacetogens from four different samples including waste activate sludge, freshwater sediment, anaerobic methanogenic sludge, and cow manure using H2/CO2 (4:1) or formate as substrate for homoacetogen enrichment. Along with the formyltetrahydrofolate synthetase (FTHFS) gene (fhs gene)-specific real time qPCR assay and Terminal Restriction Fragment Length Polymorphism (T-RFLP) analysis, 16S rRNA based 454 high-throughput pyrosequencing was applied to reveal the population dynamic and community structure during enrichment from different origins. Enrichment of homoacetogenic populations coincided with accumulations of short chain fatty acids such as acetate and butyrate. 454 high-throughput pyrosequencing revealed Firmicutes and Spirochaetes populations became dominant while the overall microbial diversity decreased after enrichment. The most abundant sequences among the four origins belonged to the following phyla: Firmicutes, Spirochaetes, Proteobacteria, and Bacteroidetes, accounting for 62.1%-99.1% of the total reads. The major putative homoacetogenic species enriched on H2/CO2 or formate belonged to Clostridium spp., Acetobacterium spp., Acetoanaerobium spp

  15. Microbial Community Succession during Lactate Amendment and Electron Acceptor Limitation Reveals a Predominance of Metal-Reducing Pelosinus spp.

    PubMed Central

    Mosher, Jennifer J.; Phelps, Tommy J.; Podar, Mircea; Hurt, Richard A.; Campbell, James H.; Drake, Meghan M.; Moberly, James G.; Schadt, Christopher W.; Brown, Steven D.; Hazen, Terry C.; Arkin, Adam P.; Palumbo, Anthony V.; Faybishenko, Boris A.

    2012-01-01

    The determination of the success of in situ bioremediation strategies is complex. By using controlled laboratory conditions, the influence of individual variables, such as U(VI), Cr(VI), and electron donors and acceptors on community structure, dynamics, and the metal-reducing potential can be studied. Triplicate anaerobic, continuous-flow reactors were inoculated with Cr(VI)-contaminated groundwater from the Hanford, WA, 100-H area, amended with lactate, and incubated for 95 days to obtain stable, enriched communities. The reactors were kept anaerobic with N2 gas (9 ml/min) flushing the headspace and were fed a defined medium amended with 30 mM lactate and 0.05 mM sulfate with a 48-h generation time. The resultant diversity decreased from 63 genera within 12 phyla to 11 bacterial genera (from 3 phyla) and 2 archaeal genera (from 1 phylum). Final communities were dominated by Pelosinus spp. and to a lesser degree, Acetobacterium spp., with low levels of other organisms, including methanogens. Four new strains of Pelosinus were isolated, with 3 strains being capable of Cr(VI) reduction while one also reduced U(VI). Under limited sulfate, it appeared that the sulfate reducers, including Desulfovibrio spp., were outcompeted. These results suggest that during times of electron acceptor limitation in situ, organisms such as Pelosinus spp. may outcompete the more-well-studied organisms while maintaining overall metal reduction rates and extents. Finally, lab-scale simulations can test new strategies on a smaller scale while facilitating community member isolation, so that a deeper understanding of community metabolism can be revealed. PMID:22267668

  16. Electrosynthesis of Commodity Chemicals by an Autotrophic Microbial Community

    PubMed Central

    Marshall, Christopher W.; Ross, Daniel E.; Fichot, Erin B.; Norman, R. Sean

    2012-01-01

    A microbial community originating from brewery waste produced methane, acetate, and hydrogen when selected on a granular graphite cathode poised at −590 mV versus the standard hydrogen electrode (SHE) with CO2 as the only carbon source. This is the first report on the simultaneous electrosynthesis of these commodity chemicals and the first description of electroacetogenesis by a microbial community. Deep sequencing of the active community 16S rRNA revealed a dynamic microbial community composed of an invariant Archaea population of Methanobacterium spp. and a shifting Bacteria population. Acetobacterium spp. were the most abundant Bacteria on the cathode when acetogenesis dominated. Methane was generally the dominant product with rates increasing from <1 to 7 mM day−1 (per cathode liquid volume) and was concomitantly produced with acetate and hydrogen. Acetogenesis increased to >4 mM day−1 (accumulated to 28.5 mM over 12 days), and methanogenesis ceased following the addition of 2-bromoethanesulfonic acid. Traces of hydrogen accumulated during initial selection and subsequently accelerated to >11 mM day−1 (versus 0.045 mM day−1 abiotic production). The hypothesis of electrosynthetic biocatalysis occurring at the microbe-electrode interface was supported by a catalytic wave (midpoint potential of −460 mV versus SHE) in cyclic voltammetry scans of the biocathode, the lack of redox active components in the medium, and the generation of comparatively high amounts of products (even after medium exchange). In addition, the volumetric production rates of these three commodity chemicals are marked improvements for electrosynthesis, advancing the process toward economic feasibility. PMID:23001672

  17. Non-growth-associated demethylation of dimethylsulfoniopropionate by (homo)acetogenic bacteria.

    PubMed

    Jansen, M; Hansen, T A

    2001-01-01

    The demethylation of the algal osmolyte dimethylsulfoniopropionate (DMSP) to methylthiopropionate (MTPA) by (homo)acetogenic bacteria was studied. Five Eubacterium limosum strains (including the type strain), Sporomusa ovata DSM 2662(T), Sporomusa sphaeroides DSM 2875(T), and Acetobacterium woodii DSM 1030(T) were shown to demethylate DMSP stoichiometrically to MTPA. The (homo)acetogenic fermentation based on this demethylation did not result in any significant increase in biomass. The analogous demethylation of glycine betaine to dimethylglycine does support growth of acetogens. In batch cultures of E. limosum PM31 DMSP and glycine betaine were demethylated simultaneously. In mixed substrates experiments with fructose-DMSP or methanol-DMSP, DMSP was used rapidly but only after exhaustion of the fructose or the methanol. In steady-state fructose-limited chemostat cultures (at a dilution rate of 0.03 h(-1)) with DMSP as a second reservoir substrate, DMSP was biotransformed to MTPA but this did not result in higher biomass values than in cultures without DMSP; cells from such cultures demethylated DMSP at rates of approximately 50 nmol min(-1) mg of protein(-1), both after growth in the presence of DMSP and after growth in its absence. In cell extracts of glycine betaine-grown strain PM31, DMSP demethylation activities of 21 to 24 nmol min(-1) mg of protein(-1) were detected with tetrahydrofolate as a methyl acceptor; the activities seen with glycine betaine were approximately 10-fold lower. A speculative explanation for the demethylation of DMSP without an obvious benefit for the organism is that the DMSP-demethylating activity is catalyzed by the glycine betaine-demethylating enzyme and that a transport-related factor, in particular a higher energy demand for DMSP transport across the cytoplasmic membrane than for glycine betaine transport, may reduce the overall ATP yield of the fermentation to virtually zero. PMID:11133459

  18. The stable carbon isotope biogeochemistry of acetate and methane in freshwater environments

    SciTech Connect

    Gelwicks, J.T.

    1989-01-01

    Methane produced in freshwater sediments, where acetate is the major substrate utilized by methanogenic bacteria, is commonly depleted in {sup 13}C. Variations in the carbon-isotopic composition of methane have been related to flows of acetate carbon to various fates within microbial communities. To examine these processes, the isotopic compositions of biogenic methane and its sedimentary sources (acetate and CO{sub 2}) were considered along with related isotope effects. A method of preparation for carbon isotope analyses of both carbons in acetate was developed. Uncertainties in measurements are less than 0.4{per thousand} for samples greater than 5 {mu}mol of acetate. Advantages of this technique include good separation of acetate from other compounds and the applicability to samples containing micromolar quantities of acetate. Carbon kinetic isotope effects associated with synthesis of acetate from CO{sub 2} by Acetobacterium woodii were measured by isotopic analyses of CO{sub 2}, methyl-carbon, and total acetate. Closed systems allowing construction of complete mass balances at varying stages of growth were utilized, and the effects of the partitioning of carbon between CO{sub 2} and HCO{sub 3}{sup {minus}} were taken into account. For the overall reaction total carbonate {yields} total acetate, the isotope effect measured {minus}58.6 {plus minus} 0.7{per thousand}; there is no evidence for intramolecular isotopic ordering in the acetate. Carbon isotope effects associated with synthesis of methane from acetate by Methanosarcina barkeri and by a natural community of methanogens were measured in closed system experiments. For the process of methyl-carbon {yields} methane, the isotope effect measured {minus}21.5 {plus minus} 1.3{per thousand}.

  19. Hydrogen-dependent oxygen reduction by homoacetogenic bacteria isolated from termite guts.

    PubMed

    Boga, Hamadi I; Brune, Andreas

    2003-02-01

    Although homoacetogenic bacteria are generally considered to be obligate anaerobes, they colonize the intestinal tracts of termites and other environments that are not entirely anoxic in space or time. In this study, we investigated how homoacetogenic bacteria isolated from the hindguts of various termites respond to the presence of molecular oxygen. All strains investigated formed growth bands in oxygen gradient agar tubes under a headspace of H(2)-CO(2). The position of the bands coincided with the oxic-anoxic interface and depended on the O(2) partial pressure in the headspace; the position of the bands relative to the meniscus remained stable for more than 1 month. Experiments with dense cell suspensions, performed with Clark-type O(2) and H(2) electrodes, revealed a large capacity for H(2)-dependent oxygen reduction in Sporomusa termitida and Sporomusa sp. strain TmAO3 (149 and 826 nmol min(-1) mg of protein(-1), respectively). Both strains also reduced O(2) with endogenous reductants, albeit at lower rates. Only in Acetonema longum did the basal rates exceed the H(2)-dependent rates considerably (181 versus 28 nmol min(-1) mg of protein)(-1)). Addition of organic substrates did not stimulate O(2) consumption in any of the strains. Nevertheless, reductive acetogenesis by cell suspensions of strain TmAO3 was inhibited even at the lowest O(2) fluxes, and growth in nonreduced medium occurred only after the bacteria had rendered the medium anoxic. Similar results were obtained with Acetobacterium woodii, suggesting that the results are not unique to the strains isolated from termites. We concluded that because of their tolerance to temporary exposure to O(2) at low partial pressures (up to 1.5 kPa in the case of strain TmAO3) and because of their large capacity for O(2) reduction, homoacetogens can reestablish conditions favorable for growth by actively removing oxygen from their environment. PMID:12570995

  20. Acetogenesis from dichloromethane by a two-component mixed culture comprising a novel bacterium.

    PubMed

    Magli, A; Rainey, F A; Leisinger, T

    1995-08-01

    A strictly anaerobic two-component culture able to grow exponentially with a doubling time of 20 h on a medium containing dichloromethane as the carbon and energy source was characterized. On a medium without sulfate, we observed (per mol of dichloromethane) a mass balance of 2 mol of chloride, 0.26 mol of acetate, 0.05 mol of formate, and 0.25 mol of carbon in biomass. One component of the culture, strain DMB, was identified by a 16S ribosomal DNA analysis as a Desulfovibrio sp. The other component, the gram-positive organism strain DMC, could not be isolated. It was possible, however, to associate strain DMC on a medium containing dichloromethane in a coculture with Acetobacterium woodii or Methanospirillum hungatei. Coculture of strain DMC with the Archaeon M. hungatei allowed us to specifically amplify by PCR the 16S rRNA gene of strain DMC. A phylogenetic analysis of the 16S ribosomal DNA sequence revealed that this organism groups within the radiation of the Clostridium-Bacillus subphylum and exhibits the highest levels of sequence similarity (89%) with Desulfotomaculum orientis and Desulfitobacterium dehalogenans. Since the novel organism strain DMC was able to grow acetogenically with dichloromethane when it was associated with one of three metabolically different partners and since, in contrast to strain DMB, strain DMC contained carbon monoxide dehydrogenase activity, this bacterium is responsible for both the dehalogenation of dichloromethane and the acetogenesis observed in the original two-component culture. The obligatory dependence of strain DMC on a partner during growth with dichloromethane is thought to stem from the need for a growth factor produced by the associated organism. PMID:16535097

  1. Genome-guided analysis of physiological and morphological traits of the fermentative acetate oxidizer Thermacetogenium phaeum

    PubMed Central

    2012-01-01

    Background Thermacetogenium phaeum is a thermophilic strictly anaerobic bacterium oxidizing acetate to CO2 in syntrophic association with a methanogenic partner. It can also grow in pure culture, e.g., by fermentation of methanol to acetate. The key enzymes of homoacetate fermentation (Wood-Ljungdahl pathway) are used both in acetate oxidation and acetate formation. The obvious reversibility of this pathway in this organism is of specific interest since syntrophic acetate oxidation operates close to the energetic limitations of microbial life. Results The genome of Th. phaeum is organized on a single circular chromosome and has a total size of 2,939,057 bp. It comprises 3.215 open reading frames of which 75% could be assigned to a gene function. The G+C content is 53.88 mol%. Many CRISPR sequences were found, indicating heavy phage attack in the past. A complete gene set for a phage was found in the genome, and indications of phage action could also be observed in culture. The genome contained all genes required for CO2 reduction through the Wood-Ljungdahl pathway, including two formyl tetrahydrofolate ligases, three carbon monoxide dehydrogenases, one formate hydrogenlyase complex, three further formate dehydrogenases, and three further hydrogenases. The bacterium contains a menaquinone MQ-7. No indications of cytochromes or Rnf complexes could be found in the genome. Conclusions The information obtained from the genome sequence indicates that Th. phaeum differs basically from the three homoacetogenic bacteria sequenced so far, i.e., the sodium ion-dependent Acetobacterium woodii, the ethanol-producing Clostridium ljungdahlii, and the cytochrome-containing Moorella thermoacetica. The specific enzyme outfit of Th. phaeum obviously allows ATP formation both in acetate formation and acetate oxidation. PMID:23259483

  2. Impact of biting midges on residential property values in Hervey Bay, Queensland, Australia.

    PubMed

    Ratnayake, Jay; Dale, Pat E; Sipe, Neil G; Daniels, Peter

    2006-03-01

    Biting midges (Culicoides spp.) are an important environmental health issue in Hervey Bay, an area of rapid population growth in Australia. It is also the gateway to a World Heritage area (Great Sandy Strait) and a destination for tourists. The spread of housing developments into suburbs close to midge breeding habitats has led to a problem for the local government responsible for managing biting insects in its area. Suburbs with a severe biting midge problem were found to have significantly lower residential property values than less affected suburbs. The gross reduction in value in due to the midge problem was estimated to range from more than AUS dollar 25 million, based on actual sale price, to more than AUS dollar 55 million, based on the perceptions of the most severely affected residents. PMID:16646336

  3. Trends in der IT-Sicherheit

    NASA Astrophysics Data System (ADS)

    Eckert, Claudia

    Ich möchte Ihnen einen Überblick geben über Trends, Challenges, offene Fragestellungen sowie Lösungsansätze aus dem Bereich der IT-Sicherheit. Meine Vorredner haben mir schon eine wunderbare Basis dafür geschaffen, indem sie wichtige Trends im Bereich IT bereits angesprochen haben. Deshalb werde ich auf diese Trends, nämlich das Internet of Things and Services nur noch einmal kurz eingehen, um daran dann die IT-Sicherheitsthemen, die sich aus diesen IT-Trends ergeben, zu skizzieren und anschließend Lösungen vorstellen, die insbesondere im Forschungsumfeld entwickelt werden, aber schon reif sind, auch in die unternehmerische Praxis übernommen zu werden.

  4. Intelligente Objekte - Klein, Vernetzt, Sensitiv, acatech BEZIEHT POSITION

    NASA Astrophysics Data System (ADS)

    Schon im Juni 2005 stand das Thema auf der Tagesordnung - beim acatech Symposium in Berlin zum Thema Computer in der Alltagswelt - Chancen für Deutschland?" unter der Leitung von Prof. Dr. Dieter Spath. Zum einen ging es darum, in wieweit Intelligente Objekte bereits Alltag und Wirtschaftsleben durchdringen. Zum andern um die Chancen für Deutschland, die der große Wachstumsmarkt der so genannten Ambient Intelligence" bietet. Die Beiträge dieses Symposiums analysierten insbesondere die Marktmöglichkeiten aus Sicht der Wirtschaft und die Rahmenbedingungen aus Sicht von Politik und Gesellschaft. Darüber hinaus wurden die Themen Sicherheit, die Etablierung von Anwendungen und die Integration des neuen Wissensgebietes in die Ausbildung diskutiert.

  5. Joint Patch and Multi-label Learning for Facial Action Unit Detection

    PubMed Central

    Zhao, Kaili; Chu, Wen-Sheng; De la Torre, Fernando; Cohn, Jeffrey F.; Zhang, Honggang

    2016-01-01

    The face is one of the most powerful channel of nonverbal communication. The most commonly used taxonomy to describe facial behaviour is the Facial Action Coding System (FACS). FACS segments the visible effects of facial muscle activation into 30+ action units (AUs). AUs, which may occur alone and in thousands of combinations, can describe nearly all-possible facial expressions. Most existing methods for automatic AU detection treat the problem using one-vs-all classifiers and fail to exploit dependencies among AU and facial features. We introduce joint-patch and multi-label learning (JPML) to address these issues. JPML leverages group sparsity by selecting a sparse subset of facial patches while learning a multi-label classifier. In four of five comparisons on three diverse datasets, CK+, GFT, and BP4D, JPML produced the highest average F1 scores in comparison with state-of-the art. PMID:27382243

  6. Regenerative Energieträger im Aufwind: Entwicklung der erneuerbaren Energien

    NASA Astrophysics Data System (ADS)

    Kohl, Harald

    2006-05-01

    2005 kam 4,6 % des deutschen Primär-Energieverbrauchs aus erneuerbaren Energiequellen, bei der Stromproduktion lag ihr Anteil bei 10,2 %. Wesentliche Ursache ist der Boom bei der Windkraft, die vor allem durch Offshore-Windparks auf See weiter ausbaubar ist. Die Wasserkraft lieferte in Deutschland traditionell einen großen Beitrag zur Stromerzeugung, doch ihr Ausbaupotenzial ist gering. Die Photovoltaik, die solar- und die geothermische Stromerzeugung spielen derzeit noch eine kleine Rolle. Den deutschen Bedarf an Wärmeenergie deckten 2004 die erneuerbaren Energien zu 5,4 %, vor allem aus Biomasse. Die solarthermische Wärmeerzeugung hat sich gegenüber 2000 mehr als verdoppelt. Im Straßenverkehr spielen biogene Kraftstoffe mit 5,4 % noch eine untergeordnete Rolle. Bis 2050 könnte in Deutschland der Anteil regenerativer Energien am Primär-Energieverbrauch die Fünfzigprozentmarke überschreiten.

  7. [Implementation of medical specialists brigades in the areas of Universal Health coverage: the Peruvian Ministry of Health experience, 2009-2010].

    PubMed

    Barzola-Cordero, Violeta; Llamosas, Ena; Echegaray, Ciro; Cuzco, María; Peralta, Felipe

    2011-06-01

    Peru has a high degree of inequity reflected in the distribution of morbidity and mortality, consistent with the inaccessibility to health care and human resource gap, especially in remote areas of the capital. The Peruvian Ministry of Health, recognizing the right of all people to quality health care, initiated the Universal Health Insurance (AUS), and in this context, increased access to specialized care in pilot AUS areas by brigades of specialist doctors. This article offers an approach to this strategy presents the management and implementation processes, a quantitative analysis with indicators of output / efficiency, and provides a qualitative look from the perspective of the members of the brigades. Its main findings reflect the lack of effective and efficient management, translated in the absence of: production goals, work plans, working partnerships with local stakeholders, monitoring and effective supervision, recurrent shortages of human and technological resources, and high costs. PMID:21845318

  8. Bewegungsapparat: Postcraniales Skelett und Muskulatur

    NASA Astrophysics Data System (ADS)

    Fischer, Martin S.

    Der Bewegungsapparat bestimmt die Form des Wirbeltierkörpers. So lässt sich z. B. aus der Gestalt eines Fisches auf seine bevorzugt e Schwimmweise schließen (S. 61). Bei den aquatisch en Schädeltieren dominiert die Fortbewegung mit axialem Antrieb; bei den meisten Tetrapoda findet sich eine Kombination aus axialem Antrieb und Bewegung durch Gliedmaßen. Selbst beim höchst spezialisierten Gang, der bipeden Bewegung des Menschen, sind Torsionsbewegungen des Rumpfes noch maßgeblich und bestimmen auch die Grundform des menschlichen Körpers (z. B. die Taille). Obwohl die verschiedenen Antriebsmechanismen eine funktionelle Einheit bilden, werden im Folgenden das Axialskelett sowie der Schulter- und Beckengürtel mit den zugehörigen Extremitäten getrennt besprochen.

  9. Turbulenzübergang in der Rohrströmung: Die Lösung eines alten Rätsels

    NASA Astrophysics Data System (ADS)

    Eckhardt, Bruno; Hof, Björn; Faisst, Holger

    2006-09-01

    Die Strömung von Flüssigkeiten und Gasen durch eine Röhre kann zwei Zustände annehmen. Einer ist laminar, also gleichmäßig geordnet, einer ist zeitlich-räumlich verwirbelt und turbulent. Mit dem Übergang zur Turbulenz nimmt der Strömungswiderstand drastisch zu. Vor etwa 120 Jahren beschrieb Osborne Reynolds bereits das Verhalten der Rohrströmung sehr genau. Er beobachtete, dass der Turbulenzübergang sehr empfindlich von äußeren Störungen abhängt, was bislang rätselhaft blieb. Dieses Rätsel konnte nun mit einer Kombination aus Computerstudien, Konzepten aus der nichtlinearen Dynamik und speziell entwickelten Experimenten gelöst werden.

  10. Cost-effectiveness of monitoring free flaps.

    PubMed

    Subramaniam, Shiva; Sharp, David; Jardim, Christopher; Batstone, Martin D

    2016-06-01

    Methods of free flap monitoring have become more sophisticated and expensive. This study aims to determine the cost of free flap monitoring and examine its cost effectiveness. We examined a group of patients who had had free flaps to the head and neck over a two-year period, and combined these results with costs obtained from business managers and staff. There were 132 free flaps with a success rate of 99%. The cost of monitoring was Aus $193/flap. Clinical monitoring during this time period cost Aus$25 476 and did not lead to the salvage of any free flaps. Cost equivalence is reached between monitoring and not monitoring only at a failure rate of 15.8%. This is to our knowledge the first study to calculate the cost of clinical monitoring of free flaps, and to examine its cost-effectiveness. PMID:27015730

  11. Gestaltung transparenter Geschäftsprozesse

    NASA Astrophysics Data System (ADS)

    Bergmann, Lars; Crespo, Isabel; Fleischmann, Jürgen

    Ein Geschäftsprozess beschreibt eine sich regelmäßig wiederholende Folge von Arbeitsschritten oder Tätigkeiten, um ein definiertes Ergebnis zu erzielen. Geschäftsprozesse besitzen daher immer ein definiertes Ziel, einen Auslöser und ein Ergebnis. In der Regel verlaufen Geschäftsprozesse abteilungs- und bereichsübergreifend. Zur Abbildung von Geschäftsprozessen sind daher Mitarbeiter aus verschiedenen Abteilungen/Bereichen einzubinden. Ein typisches Beispiel für einen Geschäftsprozess in produzierenden Unternehmen ist der Auftragsabwicklungsprozess. Der Kunde löst mit seinem Auftrag den Prozess aus, der als Ergebnis die Auslieferung eines Produktes zur Folge hat. Je nach Art des Geschäftsprozesses und Größe eines Unternehmens sind unterschiedlich viele Mitarbeiter an einem Prozess beteiligt.

  12. Implementierungstechniken

    NASA Astrophysics Data System (ADS)

    Lippe, Wolfram-Manfred

    Die klassische Technik zur Implementierung funktionaler und applikativer Sprachen ist die des Interpretierens. Stammvater aller Interpretierer ist der in Kapitel 3.2.2.12 vorgestellte Interpretierer von McCarthy. Das Hauptproblem aller Implementierungstechniken, die Bindung von Werten an Namen, wird bei ihm durch das Konzept der Assoziationsliste (A-Liste) realisiert. Die Elemente dieser Liste sind Paare, deren 1. Komponente aus einem Namen und deren 2. Komponenete aus einem Wert besteht. Anschaulich kann man sich die A-Liste als einen Keller vorstellen, in den bei jeder Bindung eines Wertes an einen Namen, z.B. bei einer Funktions-Deklaration (Label-Deklaration) oder einer Funktionsapplikation, das entsprechende Paar gespeichert wird.

  13. Osteognathostomata

    NASA Astrophysics Data System (ADS)

    Schultze, Hans-Peter

    Noch häufig, vor allem im englischen Sprachraum, wird für die fischartigen Wirbeltiere mit Knochenskelett, also die Actinopterygii und Sarcopterygii, der Begriff "Osteichthyes" (Knochenfische) verwendet. Da sich jedoch aus einem Subtaxon der Sarcopterygier die Tet rapoda entwickelten (S. 322), würde diese Gruppierung ein paraphyletisches Taxon darstellen. Hier wird daher dem Vorschlag W. Hennigs (1983) gefolgt und die Schwestergruppe der Chondrichthyes Osteognathostomata genannt: Sie enthält alle weiteren kiefertragenden Wirbeltiere mit Knochenskelett (Name!) (Abb. 201). Die Sarcopterygii umfassen demnach verschiedene fossile Gruppen, die rezenten Reliktgruppen der Dipnoi (Lungenfische) und Actinistia (Hohlstachler) sowie die Tetrapoda und ihre Stammgruppenvertreter. (Neuerdings wird in der Literatur aus denselben Gründen einer konsequent phylogenetischen Systematisierung wieder die Gruppierung Osteichthyes, aber unter Einschluss der Tetrapoda, verwendet!).

  14. Complexity of indica-japonica varietal differentiation in Bangladesh rice landraces revealed by microsatellite markers

    PubMed Central

    Wang, Mumu; Zhu, Zuofeng; Tan, Lubin; Liu, Fengxia; Fu, Yongcai; Sun, Chuanqing; Cai, Hongwei

    2013-01-01

    To understand the genetic diversity and indica-japonica differentiation in Bangladesh rice varieties, a total of 151 accessions of rice varieties mostly Bangladesh traditional varieties including Aus, Boro, broadcast Aman, transplant Aman and Rayada varietal groups were genotyped using 47 rice nuclear SSRs. As a result, three distinct groups were detected by cluster analysis, corresponding to indica, Aus and japonica rice. Among deepwater rice varieties analyzed some having particular morphological features that mainly corresponded to the japonica varietal group. Some small seeded and aromatic varieties from Bangladesh also corresponded to the japonica varietal group. This research for the first time establishes that the japonica varietal group is a prominent component of traditional varieties in Bangladesh, particularly in deepwater areas. PMID:23853518

  15. Screening and predicting posttraumatic stress and depression in children following single-incident trauma.

    PubMed

    Nixon, Reginald D V; Ellis, Alicia A; Nehmy, Thomas J; Ball, Shelley-Anne

    2010-01-01

    Three screening methods to predict posttraumatic stress disorder (PTSD) and depression symptoms in children following single-incident trauma were tested. Children and adolescents (N = 90; aged 7-17 years) were assessed within 4 weeks of an injury that led to hospital treatment and followed up 3 and 6 months later. Screening methods were adapted from existing instruments and examined (a) an Australian version of the Screening Tool for Predictors of PTSD (STEPP-AUS), (b) an abbreviated measure of initial PTSD severity, and (c) an abbreviated measure of initial maladaptive trauma-specific beliefs. The STEPP-AUS correctly identified 89% of the children who developed PTSD at 6-month follow-up and the 69% of children who were non-PTSD. Predictive performance of the others instruments was generally poor, and no instrument consistently predicted subclinical levels of depression. PMID:20589569

  16. Deep genetic divergence in giant red shrimp Aristaeomorpha foliacea (Risso, 1827) across a wide distributional range

    NASA Astrophysics Data System (ADS)

    Fernández, M. V.; Heras, S.; Maltagliati, F.; Roldán, M. I.

    2013-02-01

    The giant red shrimp, Aristaeomorpha foliacea, is a commercially important species in the Mediterranean Sea (MED), Mozambique Channel (MOZ), and north western Australia (AUS). 685 bp of the mitochondrial COI gene was sequenced in 317 individuals from six Mediterranean and two Indian Ocean localities. Genetic diversity estimates of Indian Ocean samples were higher than those of MED counterparts. AMOVA, phylogenetic tree, haplotype network and Bayesian assignment analyses detected three haplogroups, corresponding to MED, MOZ and AUS, separated by three and 38 mutational steps, respectively. Within MED shallow genetic divergence between populations was dependent on local oceanographical characteristics. Mismatch distribution analysis and neutrality tests provided a consistent indication of past population expansion in each region considered. Our results provide the first evidence of genetic structure in A. foliacea and suggest a scenario of allopatric speciation within the Indian Ocean that, however needs deeper examination.

  17. Musik einpacken

    NASA Astrophysics Data System (ADS)

    Loos, Andreas

    Wer schon einmal Nudeln selbst gemacht hat, der weiß: Frische Pasta kann ganz schön pappen. Das ist ein Problem für die Nudelindustrie, denn es ist nicht leicht, mit unregelmäßigen und klebrigen Nudel-Klumpen 500-Gramm-Beutel genau zu füllen. Einige Hersteller verwenden daher "Teilmengenwaagen". Die besitzen bis zu hundert kleineWaagschalen, die über ein Förderband mit jeweils ungefähr 50 Gramm Nudel-Klumpen befüllt werden. Dann kommt Mathematik ins Spiel: Ein Computer wählt die zehn Waagschalen aus, deren Inhalt zusammen die 500 Gramm genau erreicht, und leert sie in einen Beutel aus.

  18. Web-based Recruiting for a Survey on Knowledge and Awareness of Cervical Cancer Prevention Among Young Women Living in Kanagawa Prefecture, Japan

    PubMed Central

    Miyagi, Etsuko; Motoki, Yoko; Asai-Sato, Mikiko; Taguri, Masataka; Morita, Satoshi; Hirahara, Fumiki; Wark, John D.; Garland, Suzanne M.

    2014-01-01

    Objectives Cervical cancer (CC) incidence and mortality among young women have been increasing in Japan. To develop effective measures to combat this, we assessed the feasibility of using a social networking site (SNS) to recruit a representative sample of young women to conduct a knowledge and attitude study about CC prevention via an internet-based questionnaire. Methods From July 2012 to March 2013, advertising banners targeting women aged 16 to 35 years in Kanagawa Prefecture were placed on Facebook in a similar manner as an Australian (AUS) study conducted in 16- to 25-year-olds in 2010 and on a homepage to advertise our CC advocacy activities. Eligible participants were emailed instructions for accessing our secure Web site where they completed an online survey including demographics, awareness, and knowledge of human papillomavirus (HPV) and CC. Data for the study population were compared with the general Japanese population and the AUS study. Results Among 394 women who expressed interest, 243 (62%) completed the survey, with 52% completing it via Facebook. Women aged 26 to 35 years, living in Yokohama City, with an education beyond high school, were overrepresented. Participants had high awareness and knowledge of HPV and CC, comparable with the AUS study participants. However, the self-reported HPV vaccination rate (22% among participants aged 16–25 years) and the recognition rate of the link between smoking and CC (31%) were significantly lower than in the AUS study (58% and 43%, respectively) (P < 0.05). Significant predictors of high knowledge scores about HPV included awareness of HPV vaccine (P < 0.001) and self-reported HPV vaccination (P < 0.05). Conclusions The SNS and homepage are efficient methods to recruit young women into health surveys, which can effectively be performed online. A nationwide survey using SNSs would be an appropriate next step to better understand the current lack of uptake of the national HPV vaccine program by young women

  19. Traits and QTLs for development of dry direct-seeded rainfed rice varieties.

    PubMed

    Sandhu, Nitika; Torres, Rolando O; Sta Cruz, Ma Teresa; Maturan, Paul Cornelio; Jain, Rajinder; Kumar, Arvind; Henry, Amelia

    2015-01-01

    The development of rice varieties for dry direct-seeded conditions can be accelerated by selecting suitable traits. In the present investigation, traits hypothesized to be important for direct-seeded conditions in rainfed systems, including seedling emergence, early vegetative vigour, nutrient uptake, nodal root number, and root hair length and density, were characterized to study the genetic control of these traits and their relationship with grain yield under seedling- and reproductive-stage drought stress. Two BC₂F₄ mapping populations derived from crosses of Aus276, a drought-tolerant aus variety, with MTU1010 and IR64, high-yielding indica mega-varieties, were developed and studied to identify quantitative trait loci (QTLs) that showed large and consistent effects. A total of 26 QTLs associated with 23 traits and 20 QTLs associated with 13 traits were mapped in the Aus276/3*IR64 and Aus276/3*MTU1010 populations, respectively. qGY₆.₁, qGY₁₀.₁, qGY₁.₁, and qEVV₉.₁ were found to be effective in both populations under a wide range of conditions. QTLs for several seedling-stage traits co-located with QTLs for grain yield, including early vegetative vigour and root hair length. On chromosome 5, several QTLs for nutrient uptake co-located with QTLs for root hair density and nematode gall rating. Six lines were selected from both populations based on grain yield and the presence of QTLs, and these lines typically showed improved seedling-stage traits (nodal root number, dry shoot weight, and root hair length and density). The co-located QTLs identified here can be used in research aimed at increasing the yield and adaptability of rainfed rice to direct-seeded conditions. PMID:25336682

  20. Traits and QTLs for development of dry direct-seeded rainfed rice varieties

    PubMed Central

    Sandhu, Nitika; Torres, Rolando O.; Sta Cruz, Ma. Teresa; Maturan, Paul Cornelio; Jain, Rajinder; Kumar, Arvind; Henry, Amelia

    2015-01-01

    The development of rice varieties for dry direct-seeded conditions can be accelerated by selecting suitable traits. In the present investigation, traits hypothesized to be important for direct-seeded conditions in rainfed systems, including seedling emergence, early vegetative vigour, nutrient uptake, nodal root number, and root hair length and density, were characterized to study the genetic control of these traits and their relationship with grain yield under seedling- and reproductive-stage drought stress. Two BC2F4 mapping populations derived from crosses of Aus276, a drought-tolerant aus variety, with MTU1010 and IR64, high-yielding indica mega-varieties, were developed and studied to identify quantitative trait loci (QTLs) that showed large and consistent effects. A total of 26 QTLs associated with 23 traits and 20 QTLs associated with 13 traits were mapped in the Aus276/3*IR64 and Aus276/3*MTU1010 populations, respectively. qGY6.1, qGY10.1, qGY1.1, and qEVV9.1 were found to be effective in both populations under a wide range of conditions. QTLs for several seedling-stage traits co-located with QTLs for grain yield, including early vegetative vigour and root hair length. On chromosome 5, several QTLs for nutrient uptake co-located with QTLs for root hair density and nematode gall rating. Six lines were selected from both populations based on grain yield and the presence of QTLs, and these lines typically showed improved seedling-stage traits (nodal root number, dry shoot weight, and root hair length and density). The co-located QTLs identified here can be used in research aimed at increasing the yield and adaptability of rainfed rice to direct-seeded conditions. PMID:25336682

  1. Slings in iatrogenic male incontinence: Current status

    PubMed Central

    Gallo, Fabrizio; Schenone, M.; Giberti, C.

    2010-01-01

    Objectives: The increasing number of prostatectomies entails an increasing number of patients suffering from iatrogenic incontinence despite improved surgical techniques. The severity of this problem often requires invasive treatments such as periurethral injection of bulking agents, artificial urinary sphincter (AUS) implantation, and sub-urethral sling positioning. The artificial urethral sphincter has represented, until today, the gold standard but, in the recent years, sling systems have been investigated as minimally invasive alternative options. Today, three different sling procedures are commonly performed: bone-anchored, readjustable, and trans-obturator slings systems. The aim of this review is to critically report the current status of sling systems in the treatment of iatrogenic male incontinence. Materials and Methods: MEDLINE and PubMed databases were searched and all articles between 1974 and 2009 were evaluated. Results: With regard to bone-anchored, readjustable, and trans-obturator slings systems, cure rates ranged between 58.0% and 86.0%, 55.5% and 73.0%, and 40.0% and 63.0%, respectively, while major complication rates ranged between 0 and 14.5%, 10.0 and 22.2%, and 0 and 10.0%, respectively. Conclusions: Suburethral slings are the only alternative techniques which can be favorably compared with the AUS, showing more advantages with respect to AUS implantations which are mainly represented by a quick and less invasive approach, low morbidity, and low costs. In spite of the difficulty in identifying the most effective sling procedure, overall, sling systems can be recommended for patients with persistent mild or moderate incontinence. However, the indication can also be extended to patients with severe incontinence, after appropriate counseling, allowing AUS implantation in the event of sling failure. PMID:20877609

  2. Physikgeschichte Das Rätsel bleibt

    NASA Astrophysics Data System (ADS)

    Hoffmann, Dieter

    2002-05-01

    Die jüngst erfolgte Veröffentlichung von Dokumenten aus dem Privatarchiv der Familie Bohr [1] über den geheimnisumwitterten Besuch von Werner Heisenberg in Kopenhagen im September 1941 hat in den deutschen Medien große Resonanz gefunden [2]. Tatsächlich verraten uns die jetzt veröffentlichten Dokumente sehr viel mehr über die Zeit ihres Entstehens als über den Besuch selbst.

  3. The 5-tiered categorization system for reporting cytology is sufficient for management of patients with thyroid nodules compared to the 6-tiered Bethesda system.

    PubMed

    Koh, Jieun; Moon, Hee Jung; Kim, Eun-Kyung; Kwak, Jin Young; Yoon, Jung Hyun

    2016-08-01

    To analyze whether the 5-tiered categorization system without the atypia of undetermined significance or follicular lesion of undetermined significance (AUS/FLUS) category is sufficient compared to the 6-tiered Bethesda system. This IRB-approved retrospective study was waived informed consent. The pre-Bethesda period was from March 2008 to December 2008 and the Bethesda period was from January 2012 to January 2013. Of 4677 nodules ≥10 mm with initial ultrasonography-guided fine-needle aspiration, 2553 nodules were from the pre-Bethesda period and 1754 nodules were from the Bethesda period. The utilization and malignancy rates of each category were compared between the two periods. The utilization rate of the benign category decreased from 67.7 % in the pre-Bethesda period to 60.0 % in the Bethesda period (p = 0.001). In the pre-Bethesda period, the malignancy rates of the non-diagnostic, benign, suspicious follicular neoplasm/Hürthle cell neoplasm, suspicious for malignancy, and malignancy categories were 3.8, 1.9, 25, 78.8, and 99.7 %, respectively. The malignancy rate of the benign category decreased from 1.9 to 0.3 % after the Bethesda system (p < 0.001). The utilization and malignancy rates of the AUS/FLUS category were 7 and 22.8 %. When the AUS/FLUS category was included in the benign category, the malignancy rate became 2.6 % which was not significantly different from 1.9 % in the pre-Bethesda period (p = 0.189). The malignancy rates of other categories were not significantly different. The 5-tiered categorization system without the AUS/FLUS category for reporting cytology was sufficient for management of patients with thyroid nodules compared to the 6-tiered categorization of the Bethesda system. PMID:26758996

  4. Physik gestern und heute Von der Metallstange zum Hochenergielaser

    NASA Astrophysics Data System (ADS)

    Heering, Peter

    2002-05-01

    Im Mai 1752 wurde in Marly bei Paris auf Anregung des amerikanischen Forschers und Politikers Benjamin Franklin erstmals die elektrische Natur des Blitzes nachgewiesen. Damals beschrieb Franklin auch eine technische Vorrichtung, die als Schutz von Gebäuden vor Blitzschlägen dienen sollte: den Blitzableiter. Diese aus heutiger Sicht scheinbar triviale Vorrichtung wurde aber keineswegs unmittelbar akzeptiert. Und bis heute ist die Forschung zum Schutz von Einrichtungen vor Blitzschlägen nicht abgeschlossen.

  5. Changes in and Efficacies of Indications for Invasive Prenatal Diagnosis of Cytogenomic Abnormalities: 13 Years of Experience in a Single Center

    PubMed Central

    Meng, Jinlai; Matarese, Chelsea; Crivello, Julianna; Wilcox, Katherine; Wang, Dongmei; DiAdamo, Autumn; Xu, Fang; Li, Peining

    2015-01-01

    Background Because the future application of cell-free fetal DNA screening is expected to dramatically improve the diagnostic yield and reduce unnecessary invasive procedures, it is time to summarize the indications of invasive prenatal diagnosis. This retrospective study was performed to evaluate the changes and efficacies of indications of invasive procedures for detecting cytogenomic abnormalities from 2000 to 2012. Material/Methods From our regional obstetric unit, 7818 invasive procedures were referred by indications of advance maternal age (AMA), abnormal ultrasound findings (aUS), abnormal maternal serum screening (aMSS), and family history (FH). Chromosome, fluorescence in situ hybridization (FISH), and array comparative genomic hybridization (aCGH) analyses were performed on chorionic villus sampling (CVS) and amniotic fluid (AF) specimens at the Yale Cytogenetics Laboratory. The abnormal findings from single or combined indications were compared to evaluate the diagnostic yield. Results The annual caseload declined by 57.2% but the diagnostic yield increased from 7.2% to 13.4%. Chromosomal and genomic abnormalities were detected in 752 cases (9.6%, 752/7818) and 12 cases (4%, 12/303), respectively. Significantly decreased AMA referrals and increased aUS and aMSS referrals were noted. The top 3 indications by diagnostic yield were AMA/aUS (51.4% for CVS, 24.2% for AF), aUS (34.7% for CVS, 14.5% for AF), and AMA/aMSS (17.8% for CVS, 9.9% for AF). Conclusions Over a period of 13 years, the indication of aMSS and aUS were increasing while AMA was decreasing for prenatal diagnosis of cytogenomic abnormalities, and there was a continuous trend of reduced invasive procedures. Prenatal evaluation using AMA/aUS was the most effective in detecting chromosomal abnormalities, but better indications for genomic abnormalities are needed. PMID:26143093

  6. Wirkstoffe, Medikamente und Mathematische Bildverarbeitung

    NASA Astrophysics Data System (ADS)

    Bauer, Günter J.; Lorenz, Dirk A.; Maaß, Peter; Preckel, Hartwig; Trede, Dennis

    Die Entwicklung neuer Medikamente ist langwierig und teuer. Der erste Schritt ist hierbei die Suche nach neuen Wirkstoffkandidaten, die für die Behandlung bislang schwer therapierbarer Krankheiten geeignet sind. Hierfür stehen der Pharma- und Biotechnologieindustrie riesige Substanzbibliotheken zur Verfügung. In diesen Bibliotheken werden die unterschiedlichsten Substanzen gesammelt, die entweder synthetisch hergestellt oder aus Pilzen, Bakterienkulturen und anderen Lebewesen gewonnen werden können.

  7. Meyers Großer Sternenatlas

    NASA Astrophysics Data System (ADS)

    Brunier, Serge; Fujii, Akira

    Unendliche Weiten mal ganz aus der Nähe betrachtet. Meyers Großer Sternenatlas ist ein außergewöhnlicher Bildband über den Sternenhimmel, der die Sternbilder erstmals im gleichen Größenverhältnis zeigt, wie sie am Himmel erscheinen. Die sensationellen Astrofotos und aktuellen Aufnahmen des Hubble-Weltraumteleskops werden Gelegenheitsbeobachter und Hobbyastronomen gleichermaßen begeistern.

  8. The Power of Inbreeding: NGS-Based GWAS of Rice Reveals Convergent Evolution during Rice Domestication.

    PubMed

    Wang, Hongru; Xu, Xun; Vieira, Filipe Garrett; Xiao, Yunhua; Li, Zhikang; Wang, Jun; Nielsen, Rasmus; Chu, Chengcai

    2016-07-01

    Low-coverage whole-genome sequencing is an effective strategy for genome-wide association studies in humans, due to the availability of large reference panels for genotype imputation. However, it is unclear whether this strategy can be utilized in other species without reference panels. Using simulations, we show that this approach is even more relevant in inbred species such as rice (Oryza sativa L.), which are effectively haploid, allowing easy haplotype construction and imputation-based genotype calling, even without the availability of large reference panels. We sequenced 203 rice varieties with well-characterized phenotypes from the United States Department of Agriculture Rice Mini-Core Collection at an average depth of 1.5× and used the data for mapping three traits. For the first two traits, amylose content and seed length, our approach leads to direct identification of the previously identified causal SNPs in the major-effect loci. For the third trait, pericarp color, an important trait underwent selection during domestication, we identified a new major-effect locus. Although known loci can explain color variation in the varieties of two main subspecies of Asian domesticated rice, japonica and indica, the new locus identified is unique to another domesticated rice subgroup, aus, and together with existing loci, can fully explain the major variation in pericarp color in aus. Our discovery of a unique genetic basis of white pericarp in aus provides an example of convergent evolution during rice domestication and suggests that aus may have a domestication history independent of japonica and indica. PMID:27179918

  9. Physik gestern und heute Vom Arbeitshaus zur Supernova

    NASA Astrophysics Data System (ADS)

    Heering, Peter

    2004-01-01

    In der letzten Ausgabe stellten wir einige Arbeiten des Grafen von Rumford vor. Unter seinen vielfältigen Entwicklungen findet sich auch die Beschreibung eines der ersten Photometer. Diese Arbeiten aus dem Jahre 1792 führten letztlich zu einer Definition der Lichtstärke, die lange Zeit gebräuchlich war. Rumfords Konzept der Standardkerze findet sich heute unter anderem in der Astronomie wieder.

  10. Assessment of undiscovered continuous oil and gas resources in the Monterey Formation, San Joaquin Basin Province, California, 2015

    USGS Publications Warehouse

    Tennyson, Marilyn E.; Charpentier, Ronald R.; Klett, Timothy R.; Brownfield, Michael E.; Pitman, Janet K.; Gaswirth, Stephanie B.; Hawkins, Sarah J.; Lillis, Paul G.; Marra, Kristen R.; Mercier, Tracey J.; Leathers, Heidi M.; Schenk, Christopher J.; Whidden, Katherine J.

    2015-01-01

    Using a geology-based assessment methodology, the U.S. Geological Survey assessed mean volumes of 21 million barrels of oil (MMBO), 27 billion cubic feet of gas, and 1 million barrels of natural gas liquids in two assessment units (AUs) that may contain continuous oil resources. Mean volumes of oil for the individual assessment units are 14 MMBO in the Monterey Buttonwillow AU and 7 MMBO in the Monterey Maricopa AU.

  11. Cost-effectiveness analysis of population-based screening of hepatocellular carcinoma: Comparing ultrasonography with two-stage screening

    PubMed Central

    Kuo, Ming-Jeng; Chen, Hsiu-Hsi; Chen, Chi-Ling; Fann, Jean Ching-Yuan; Chen, Sam Li-Sheng; Chiu, Sherry Yueh-Hsia; Lin, Yu-Min; Liao, Chao-Sheng; Chang, Hung-Chuen; Lin, Yueh-Shih; Yen, Amy Ming-Fang

    2016-01-01

    AIM: To assess the cost-effectiveness of two population-based hepatocellular carcinoma (HCC) screening programs, two-stage biomarker-ultrasound method and mass screening using abdominal ultrasonography (AUS). METHODS: In this study, we applied a Markov decision model with a societal perspective and a lifetime horizon for the general population-based cohorts in an area with high HCC incidence, such as Taiwan. The accuracy of biomarkers and ultrasonography was estimated from published meta-analyses. The costs of surveillance, diagnosis, and treatment were based on a combination of published literature, Medicare payments, and medical expenditure at the National Taiwan University Hospital. The main outcome measure was cost per life-year gained with a 3% annual discount rate. RESULTS: The results show that the mass screening using AUS was associated with an incremental cost-effectiveness ratio of USD39825 per life-year gained, whereas two-stage screening was associated with an incremental cost-effectiveness ratio of USD49733 per life-year gained, as compared with no screening. Screening programs with an initial screening age of 50 years old and biennial screening interval were the most cost-effective. These findings were sensitive to the costs of screening tools and the specificity of biomarker screening. CONCLUSION: Mass screening using AUS is more cost effective than two-stage biomarker-ultrasound screening. The most optimal strategy is an initial screening age at 50 years old with a 2-year inter-screening interval. PMID:27022228

  12. Assessment of Appalachian basin oil and gas resources: Utica-Lower Paleozoic Total Petroleum System: Chapter G.10 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

    USGS Publications Warehouse

    Ryder, Robert T.

    2014-01-01

    Both conventional oil and gas resources and continuous (unconventional) gas resources are present in the UticaLower Paleozoic TPS. Conventional oil and gas resources in the Utica-Lower Paleozoic TPS were assessed by the U.S. Geological Survey (USGS) in 2002 in the following assessment units (AU): (1) the Lower Paleozoic Carbonates in Thrust Belt AU, (2) the Knox Unconformity AU, (3) the Black River-Trenton Hydrothermal Dolomite AU, and (4) the Lockport Dolomite AU. The total estimated undiscovered oil and gas resources for these four AUs, at a mean value, was about 46 million barrels of oil (MMBO) and about 3 trillion cubic feet of gas (TCFG), respectively. In contrast, continuous (unconventional) gas resources in the TPS were assessed by the USGS in 2002 in four AUs associated with the “Clinton” sandstone, Medina sandstone, Medina Group sandstones, Tuscarora Sandstone, and sandstones in the Queenston Shale. The total estimated undiscovered gas for these four AUs, at a mean value, was about 26.8 TCFG. A hypothetical Utica Shale AU for oil(?) and continuous gas is identified in this report. In 2012, the Utica Shale was recognized by the USGS as a continuous AU and was assessed by Kirschbaum and others (2012).

  13. Gestresste Haut? - Aktueller Stand molekularer psychosomatischer Zusammenhänge und ihr Beitrag zu Ursachen und Folgen dermatologischer Erkrankungen.

    PubMed

    Peters, Eva M J

    2016-03-01

    In den 70er Jahren des vergangenen Jahrhunderts wurde zum ersten Mal ein pathogenetisch relevanter Zusammenhang zwischen Stress, im Sinne von psychosozialem Stress, und Krankheit am Beispiel von viralen Erkrankungen der Schleimhäute (wie Rhinovirus-, Coxsackie-Infektion) nachgewiesen. Seither nehmen Publikationen, die diese Zusammenhänge bis auf die molekulare Ebene erforschen, jährlich zu. Dennoch sind die Evidenzen für einen Einfluss von psychosozialer Belastung auf chronisch-entzündliche Hauterkrankungen und auf Hauttumoren wenig bekannt. In diesem Beitrag fassen wir die aktuellen Erkenntnisse aus Epidemiologie, Psychoneuroimmunologie und molekularer Psychosomatik narrativ zusammen. Sie belegen die vielfältigen krankheitsrelevanten Interaktionen zwischen endokrinem System, Nervensystem und Immunsystem. Im Fokus stehen stressinduzierte Verschiebungen in der Immunbalance bei ausgewählten Erkrankungen wie Neurodermitis, Psoriasis oder malignem Melanom. Ziel dieses Beitrages ist die Vermittlung psychosomatischen Grundlagenwissens bei chronischen Dermatosen. Dies reicht von der Ätiologie über die Symptomatik bis zu den therapeutischen Optionen. Besonderes Augenmerk liegt dabei auf den zugrunde liegenden molekularen Zusammenhängen sowohl aus der somatopsychischen als auch aus der psychosomatischen Perspektive. PMID:26972186

  14. Die grünende IT - Wie die Computerindustrie das Energiesparen neu erfand

    NASA Astrophysics Data System (ADS)

    von Greiner, Wilhelm

    Die IT-Branche hat ihr grünes Gewissen entdeckt. In der jetzigen Verbreitung und Intensität ist dieses Phänomen noch recht neu - lange Zeit schien die Informationstechnik in puncto Umweltverträglichkeit und Energieverbrauch eine "weiße Weste" zu haben. Schließlich läuft ein PC mit Strom und nicht mit - sagen wir mal - einem Dieselmotor: Beim Booten eines Computers schießt nicht erst eine dunkelgraue Rauchwolke aus dem Auspuff, die Lärmerzeugung beschränkt sich auf das Surren des Lüfters, zum Tanken fahren muss man mit ihm auch nicht, und die Produktion der Komponenten erfolgt… ja, wo eigentlich? Irgendwo in der "dritten Welt", in Fernost oder in Mexiko. So sind die umweltschädlichen Aspekte der Produktion von Leiterplatten und sonstigen Bauteilen aus den Augen, aus dem Sinn und bestenfalls sporadisch Gegenstand eines kritischen Greenpeace-Berichts1, der im Überangebot der Medienlandschaft untergeht.

  15. Isomorphism and solid solutions among Ag- and Au-selenides

    NASA Astrophysics Data System (ADS)

    Palyanova, Galina A.; Seryotkin, Yurii V.; Kokh, Konstantin A.; Bakakin, Vladimir V.

    2016-09-01

    Au-Ag selenides were synthesized by heating stoichiometric mixtures of elementary substances of initial compositions Ag2-xAuxSe with a step of x=0.25 (0≤x≤2) to 1050 °C and annealing at 500 °C. Scanning electron microscopy, optical microscopy, electron microprobe analysis and X-ray powder diffraction methods have been applied to study synthesized samples. Results of studies of synthesized products revealed the existence of three solid solutions with limited isomorphism Ag↔Au: naumannite Ag2Se - Ag1.94Au0.06Se, fischesserite Ag3AuSe2 - Ag3.2Au0.8Se2 and gold selenide AuSe - Au0.94Ag0.06Se. Solid solutions and AgAuSe phases were added to the phase diagram of Ag-Au-Se system. Crystal-chemical interpretation of Ag-Au isomorphism in selenides was made on the basis of structural features of fischesserite, naumannite, and AuSe.

  16. Multilocus comparative phylogeography of two aristeid shrimps of high commercial interest (Aristeus antennatus and Aristaeomorpha foliacea) reveals different responses to past environmental changes.

    PubMed

    Fernández, Maria Victoria; Heras, Sandra; Viñas, Jordi; Maltagliati, Ferruccio; Roldán, Maria Inés

    2013-01-01

    Phylogeographical studies can reveal hidden patterns in the evolutionary history of species. Comparative analyses of closely related species can further help disentangle the relative contributions of processes responsible for such patterns. In this work, the phylogeography of two aristeid species, Aristeus antennatus and Aristaeomorpha foliacea, was compared through multiple genetic markers. These marine shrimp species are of high commercial importance, and are exploited in the Mediterranean Sea (MED) and in Mozambique Channel (MOZ) where they occur in partial sympatry. Aristeus antennatus (N = 50) from Western and Eastern Mediterranean (WM and EM, respectively), Atlantic Ocean (AO) and MOZ, and Aristaeomorpha foliacea (N = 40) from WM, EM, MOZ North-Western Australia (AUS) were analyzed with two nuclear genes (PEPCK and NaK) and one mitochondrial (COI) gene. Within the study area differences were found between the two species in their phylogeographical patterns, suggesting distinct responses to environmental changes. Monophyly of Aristeus antennatus was found across its distributional range. This pattern contrasted by a deep evolutionary split within Aristaeomorpha foliacea where genetic diversity followed geography distinguishing MED-MOZ and AUS. We propose that the AUS lineage of A. foliacea warrants consideration as a distinct species, with consequent implications in systematics and resource management. PMID:23516594

  17. Extremophile microbiomes in acidic and hypersaline river sediments of Western Australia.

    PubMed

    Lu, Shipeng; Peiffer, Stefan; Lazar, Cassandre Sara; Oldham, Carolyn; Neu, Thomas R; Ciobota, Valerian; Näb, Olga; Lillicrap, Adam; Rösch, Petra; Popp, Jürgen; Küsel, Kirsten

    2016-02-01

    We investigated the microbial community compositions in two sediment samples from the acidic (pH ∼3) and hypersaline (>4.5% NaCl) surface waters, which are widespread in Western Australia. In West Dalyup River, large amounts of NaCl, Fe(II) and sulfate are brought by the groundwater into the surface run-off. The presence of K-jarosite and schwertmannite minerals in the river sediments suggested the occurrence of microbial Fe(II) oxidation because chemical oxidation is greatly reduced at low pH. 16S rRNA gene diversity analyses revealed that sequences affiliated with an uncultured archaeal lineage named Aplasma, which has the genomic potential for Fe(II) oxidation, were dominant in both sediment samples. The acidophilic heterotrophs Acidiphilium and Acidocella were identified as the dominant bacterial groups. Acidiphilium strain AusYE3-1 obtained from the river sediment tolerated up to 6% NaCl at pH 3 under oxic conditions and cells of strain AusYE3-1 reduced the effects of high salt content by forming filamentous structure clumping as aggregates. Neither growth nor Fe(III) reduction by strain AusYE3-1 was observed in anoxic salt-containing medium. The detection of Aplasma group as potential Fe(II) oxidizers and the inhibited Fe(III)-reducing capacity of Acidiphilium contributes to our understanding of the microbial ecology of acidic hypersaline environments. PMID:26524974

  18. Revisiting the S-Au(111) interaction: Static or Dynamic?

    SciTech Connect

    Biener, M M; Biener, J; Friend, C M

    2004-08-17

    The chemical inertness typically observed for Au does not imply a general inability to form stable bonds with non-metals but is rather a consequence of high reaction barriers. The Au-S interaction is probably the most intensively studied interaction of Au surfaces with non-metals as, for example, it plays an important role in Au ore formation, and controls the structure and dynamics of thiol-based self-assembled-monolayers (SAMs). In recent years a quite complex picture of the interaction of sulfur with Au(111) surfaces emerged, and a variety of S-induced surface structures was reported under different conditions. The majority of these structures were interpreted in terms of a static Au surface, where the positions of the Au atoms remain essentially unperturbed. Here we demonstrate that the Au(111) surface exhibits a very dynamic character upon interaction with adsorbed sulfur: low sulfur coverages modify the surface stress of the Au surface leading to lateral expansion of the surface layer; large-scale surface restructuring and incorporation of Au atoms into a growing two-dimensional AuS phase were observed with increasing sulfur coverage. These results provide new insight into the Au-S surface chemistry, and reveal the dynamic character of the Au(111) surface.

  19. Modular System for Neutronics Calculations of Fission Reactors, Fusion Blankets, and Other Systems.

    Energy Science and Technology Software Center (ESTSC)

    1999-07-23

    AUS is a neutronics code system which may be used for calculations of a wide range of fission reactors, fusion blankets and other neutron applications. The present version, AUS98, has a nuclear cross section library based on ENDF/B-VI and includes modules which provide for reactor lattice calculations, one-dimensional transport calculations, multi-dimensional diffusion calculations, cell and whole reactor burnup calculations, and flexible editing of results. Calculations of multi-region resonance shielding, coupled neutron and photon transport, energymore » deposition, fission product inventory and neutron diffusion are combined within the one code system. The major changes from the previous release, AUS87, are the inclusion of a cross-section library based on ENDF/B-VI, the addition of the POW3D multi-dimensional diffusion module, the addition of the MICBURN module for controlling whole reactor burnup calculations, and changes to the system as a consequence of moving from IBM mainframe computers to UNIX workstations.« less

  20. Impact of the Multi-Gene ThyroSeq Next-Generation Sequencing Assay on Cancer Diagnosis in Thyroid Nodules with Atypia of Undetermined Significance/Follicular Lesion of Undetermined Significance Cytology

    PubMed Central

    Carty, Sally E.; Chiosea, Simon I.; Coyne, Christopher; Duvvuri, Umamaheswar; Ferris, Robert L.; Gooding, William E.; LeBeau, Shane O.; Ohori, N. Paul; Seethala, Raja R.; Tublin, Mitchell E.; Yip, Linwah; Nikiforova, Marina N.

    2015-01-01

    Background: Fine-needle aspiration (FNA) cytology is a common approach to evaluate thyroid nodules. It offers definitive diagnosis of a benign or malignant nodule in the majority of cases. However, 10–25% of nodules yield one of three indeterminate cytologic diagnoses, leading to suboptimal management of these patients. Atypia of undetermined significance/follicular lesion of undermined significance (AUS/FLUS) is a common indeterminate diagnosis, with the cancer risk ranging from 6% to 48%. This study assessed whether a multi-gene next-generation sequencing (NGS) assay can offer significant improvement in diagnosis in AUS/FLUS nodules. Methods: From May 2014 to March 2015, 465 consecutive FNA samples with the cytologic diagnosis of AUS/FLUS underwent prospective molecular testing using the ThyroSeq v2.1 panel. The panel included 14 genes analyzed for point mutations and 42 types of gene fusions occurring in thyroid cancer. In addition, eight genes were assessed for expression in order to evaluate the cell composition of FNA samples. Ninety-eight (21%) of these nodules had definitive surgical (n = 96) or nonsurgical (n = 2) follow-up and were used to determine the assay performance. Results: Among 465 AUS/FLUS nodules, three were found to be composed of parathyroid cells and 462 of thyroid follicular cells. Of the latter, 31 (6.7%) were positive for mutations. The most frequently mutated genes were NRAS and HRAS, and overall point mutations in seven different genes and five types of gene fusions were identified in these nodules. Among 98 nodules with known outcome, histologic analysis revealed 22 (22.5%) cancers. ThyroSeq v2.1 was able to classify 20/22 cancers correctly, showing a sensitivity of 90.9% [confidence interval (CI) 78.8–100], specificity of 92.1% [CI 86.0–98.2], positive predictive value of 76.9% [CI 60.7–93.1], and negative predictive value of 97.2% [CI 78.8–100], with an overall accuracy of 91.8% [CI 86.4–97.3]. Conclusions: The

  1. Atomic structure of a peptide coated gold nanocluster identified using theoretical and experimental studies.

    PubMed

    Wang, Hui; Li, Xu; Gao, Liang; Zhai, Jiao; Liu, Ru; Gao, Xueyun; Wang, Dongqi; Zhao, Lina

    2016-06-01

    Peptide coated gold nanoclusters (AuNCs) have a precise molecular formula and atomic structure, which are critical for their unique applications in targeting specific proteins either for protein analysis or drug design. To date, a study of the crystal structure of peptide coated AuNCs is absent primarily due to the difficulty of obtaining their crystalline phases in an experiment. Here we study a typical peptide coated AuNC (Au24Peptide8, Peptide = H2N-CCYKKKKQAGDV-COOH, Anal. Chem., 2015, 87, 2546) to figure out its atomic structure and electronic structure using a theoretical method for the first time. In this work, we identify the explicit configuration of the essential structure of Au24Peptide8, Au24(Cys-Cys)8, using density functional theory (DFT) computations and optical spectroscopic experiments, where Cys denotes cysteine without H bonded to S. As the first multidentate ligand binding AuNC, Au24(Cys-Cys)8 is characterized as a distorted Au13 core with Oh symmetry covered by two Au(Cys-Cys) and three Au3(Cys-Cys)2 staple motifs in its atomic structure. The most stable configuration of Au24(Cys-Cys)8 is confirmed by comparing its UV-vis absorption spectrum from time-dependent density-functional theory (TDDFT) calculations with optical absorption measurements, and these results are consistent with each other. Furthermore, we carry out frontier molecular orbital (FMO) calculations to elucidate that the electronic structure of Au24(Cys-Cys)8 is different from that of Au24(SR)20 as they have a different Au/S ratio, where SR represents alkylthiolate. Importantly, the different ligand coatings, Cys-Cys and SR, in Au24(Cys-Cys)8 and Au24(SR)20 cause the different Au/S ratios in the coated Au24. The reason is that the Au/S ratio is crucial in determining the size of the Au core of the ligand protected AuNC, and the size of the Au core corresponds to a specific electronic structure. By the adjustment of ligand coatings from alkylthiolate to peptide, the Au/S ratio

  2. Identification and mapping of stable QTL with main and epistasis effect on rice grain yield under upland drought stress

    PubMed Central

    2014-01-01

    Background Drought is one of the most important abiotic stresses that cause drastic reduction in rice grain yield (GY) in rainfed environments. The identification and introgression of QTL leading to high GY under drought have been advocated to be the preferred breeding strategy to improve drought tolerance of popular rice varieties. Genetic control of GY under reproductive-stage drought stress (RS) was studied in two BC1F4 mapping populations derived from crosses of Kali Aus, a drought-tolerant aus cultivar, with high-yielding popular varieties MTU1010 and IR64. The aim was to identify QTL for GY under RS that show a large and consistent effect for the trait. Bulk segregant analysis (BSA) was used to identify significant markers putatively linked with high GY under drought. Results QTL analysis revealed major-effect GY QTL: qDTY 1.2 , qDTY 2.2 and qDTY 1.3 , qDTY 2.3 (DTY; Drought grain yield) under drought consistently over two seasons in Kali Aus/2*MTU1010 and Kali Aus/2*IR64 populations, respectively. qDTY 1.2 and qDTY 2.2 explained an additive effect of 288 kg ha−1 and 567 kg ha−1 in Kali Aus/2*MTU1010, whereas qDTY 1.3 and qDTY 2.3 explained an additive effect of 198 kg ha−1 and 147 kg ha−1 in Kali Aus/2*IR64 populations, respectively. Epistatic interaction was observed for DTF (days to flowering) between regions on chromosome 2 flanked by markers RM154–RM324 and RM263–RM573 and major epistatic QTL for GY showing interaction between genomic locations on chromosome 1 at marker interval RM488–RM315 and chromosome 2 at RM324–RM263 in 2012 DS and 2013 DS RS in Kali Aus/2*IR64 mapping populations. Conclusion The QTL, qDTY 1.2 , qDTY 1.3 , qDTY 2.2 , and qDTY 2.3, identified in this study can be used to improve GY of mega varieties MTU1010 and IR64 under different degrees of severity of drought stress through marker-aided backcrossing and provide farmers with improved varieties that effectively combine high yield potential with good yield

  3. Influence of Vitamin B12 and Cocultures on the Growth of Dehalococcoides Isolates in Defined Medium▿

    PubMed Central

    He, Jianzhong; Holmes, Victor F.; Lee, Patrick K. H.; Alvarez-Cohen, Lisa

    2007-01-01

    Bacteria belonging to the genus Dehalococcoides play a key role in the complete detoxification of chloroethenes as these organisms are the only microbes known to be capable of dechlorination beyond dichloroethenes to vinyl chloride (VC) and ethene. However, Dehalococcoides strains usually grow slowly with a doubling time of 1 to 2 days and have complex nutritional requirements. Here we describe the growth of Dehalococcoides ethenogenes 195 in a defined mineral salts medium, improved growth of strain 195 when the medium was amended with high concentrations of vitamin B12, and a strategy for maintaining Dehalococcoides strains on lactate by growing them in consortia. Although strain 195 could grow in defined medium spiked with ∼0.5 mM trichloroethene (TCE) and 0.001 mg/liter vitamin B12, the TCE dechlorination and cellular growth rates doubled when the vitamin B12 concentration was increased 25-fold to 0.025 mg/liter. In addition, the final ratios of ethene to VC increased when the higher vitamin concentration was used, which reflected the key role that cobalamin plays in dechlorination reactions. No further improvement in dechlorination or growth was observed when the vitamin B12 concentration was increased to more than 0.025 mg/liter. In defined consortia containing strain 195 along with Desulfovibrio desulfuricans and/or Acetobacterium woodii and containing lactate as the electron donor, tetrachloroethene (∼0.4 mM) was completely dechlorinated to VC and ethene and there was concomitant growth of Dehalococcoides cells. In the cultures that also contained D. desulfuricans and/or A. woodii, strain 195 cells grew to densities that were 1.5 times greater than the densities obtained when the isolate was grown alone. The ratio of ethene to VC was highest in the presence of A. woodii, an organism that generates cobalamin de novo during metabolism. These findings demonstrate that the growth of D. ethenogenes strain 195 in defined medium can be optimized by providing

  4. Influence of vitamin B12 and cocultures on the growth of Dehalococcoides isolates in defined medium.

    PubMed

    He, Jianzhong; Holmes, Victor F; Lee, Patrick K H; Alvarez-Cohen, Lisa

    2007-05-01

    Bacteria belonging to the genus Dehalococcoides play a key role in the complete detoxification of chloroethenes as these organisms are the only microbes known to be capable of dechlorination beyond dichloroethenes to vinyl chloride (VC) and ethene. However, Dehalococcoides strains usually grow slowly with a doubling time of 1 to 2 days and have complex nutritional requirements. Here we describe the growth of Dehalococcoides ethenogenes 195 in a defined mineral salts medium, improved growth of strain 195 when the medium was amended with high concentrations of vitamin B(12), and a strategy for maintaining Dehalococcoides strains on lactate by growing them in consortia. Although strain 195 could grow in defined medium spiked with approximately 0.5 mM trichloroethene (TCE) and 0.001 mg/liter vitamin B(12), the TCE dechlorination and cellular growth rates doubled when the vitamin B(12) concentration was increased 25-fold to 0.025 mg/liter. In addition, the final ratios of ethene to VC increased when the higher vitamin concentration was used, which reflected the key role that cobalamin plays in dechlorination reactions. No further improvement in dechlorination or growth was observed when the vitamin B(12) concentration was increased to more than 0.025 mg/liter. In defined consortia containing strain 195 along with Desulfovibrio desulfuricans and/or Acetobacterium woodii and containing lactate as the electron donor, tetrachloroethene ( approximately 0.4 mM) was completely dechlorinated to VC and ethene and there was concomitant growth of Dehalococcoides cells. In the cultures that also contained D. desulfuricans and/or A. woodii, strain 195 cells grew to densities that were 1.5 times greater than the densities obtained when the isolate was grown alone. The ratio of ethene to VC was highest in the presence of A. woodii, an organism that generates cobalamin de novo during metabolism. These findings demonstrate that the growth of D. ethenogenes strain 195 in defined medium

  5. Atomic structure of a peptide coated gold nanocluster identified using theoretical and experimental studies

    NASA Astrophysics Data System (ADS)

    Wang, Hui; Li, Xu; Gao, Liang; Zhai, Jiao; Liu, Ru; Gao, Xueyun; Wang, Dongqi; Zhao, Lina

    2016-06-01

    Peptide coated gold nanoclusters (AuNCs) have a precise molecular formula and atomic structure, which are critical for their unique applications in targeting specific proteins either for protein analysis or drug design. To date, a study of the crystal structure of peptide coated AuNCs is absent primarily due to the difficulty of obtaining their crystalline phases in an experiment. Here we study a typical peptide coated AuNC (Au24Peptide8, Peptide = H2N-CCYKKKKQAGDV-COOH, Anal. Chem., 2015, 87, 2546) to figure out its atomic structure and electronic structure using a theoretical method for the first time. In this work, we identify the explicit configuration of the essential structure of Au24Peptide8, Au24(Cys-Cys)8, using density functional theory (DFT) computations and optical spectroscopic experiments, where Cys denotes cysteine without H bonded to S. As the first multidentate ligand binding AuNC, Au24(Cys-Cys)8 is characterized as a distorted Au13 core with Oh symmetry covered by two Au(Cys-Cys) and three Au3(Cys-Cys)2 staple motifs in its atomic structure. The most stable configuration of Au24(Cys-Cys)8 is confirmed by comparing its UV-vis absorption spectrum from time-dependent density-functional theory (TDDFT) calculations with optical absorption measurements, and these results are consistent with each other. Furthermore, we carry out frontier molecular orbital (FMO) calculations to elucidate that the electronic structure of Au24(Cys-Cys)8 is different from that of Au24(SR)20 as they have a different Au/S ratio, where SR represents alkylthiolate. Importantly, the different ligand coatings, Cys-Cys and SR, in Au24(Cys-Cys)8 and Au24(SR)20 cause the different Au/S ratios in the coated Au24. The reason is that the Au/S ratio is crucial in determining the size of the Au core of the ligand protected AuNC, and the size of the Au core corresponds to a specific electronic structure. By the adjustment of ligand coatings from alkylthiolate to peptide, the Au/S ratio

  6. General synthetic approach to heterostructured nanocrystals based on noble metals and I-VI, II-VI, and I-III-VI metal chalcogenides.

    PubMed

    Liu, Minghui; Zeng, Hua Chun

    2014-08-19

    Solid metal precursors (alloys or monometals) can serve both as a starting template and as a source material for chemical transformation to metal chalcogenides. Herein, we develop a simple solution-based strategy to obtain highly monodisperse noble-metal-based heterostructured nanocrystals from such precursor seeds. By utilizing chemical and structural inhomogeneity of these metal seeds, in this work, we have synthesized a total of five I-VI (Ag2S, Ag2Se, Ag3AuS2, Ag3AuSe2, and Cu9S5), three II-VI (CdS, CdSe, and CuSe), and four I-III-VI (AgInS2, AgInSe2, CuInS2, and CuInSe2) chalcogenides, together with their fifteen associated heterodimers (Au-Ag2S, Au-Ag2Se, Au-Ag3AuS2, Au-Ag3AuSe2, Au-AgInS2, Au-AgInSe2, Au-CdS, Au-CdSe, Ag-Ag2S, Ag-AgInS2, Au-Cu9S5, Au-CuInS2, Au-CuSe, Au-CuInSe2, and Pt-AgInS2) to affirm the process generality. Briefly, by adding elemental sulfur or selenium to AuAg alloy seeds and tuning the reaction conditions, we can readily obtain phase-pure Au-Ag2S, Au-Ag2Se, Au-Ag3AuS2, and Au-Ag3AuSe2 heterostructures. Similarly, we can also fabricate Au-AgInS2 and Au-AgInSe2 heterostructures from the AuAg seeds by adding sulfur/selenium and indium precursors. Furthermore, by partial or full conversion of Ag seeds, we can prepare both single-phase Ag chalcogenide nanocrystals and Ag-based heterostructures. To demonstrate wide applicability of this strategy, we have also synthesized Au-based binary and ternary Cu chalcogenide (Au-Cu9S5, Au-CuSe, Au-CuInS2, and Au-CuInSe2) heterostructures from alloy seeds of AuCu and Pt chalcogenides (e.g., Pt-AgInS2) from alloy seeds of PtAg. The structure and composition of the above products have been confirmed with X-ray diffraction, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and energy-dispersive X-ray spectroscopy methods. A kinetic investigation of the formation mechanism of these heterostructures is brought forward using Au-AgInS2 and Ag-CuInS2 as model examples. PMID

  7. Halorubrum chaoviator sp. nov., a haloarchaeon isolated from sea salt in Baja California, Mexico, Western Australia and Naxos, Greece.

    PubMed

    Mancinelli, Rocco L; Landheim, Ragnhild; Sánchez-Porro, Cristina; Dornmayr-Pfaffenhuemer, Marion; Gruber, Claudia; Legat, Andrea; Ventosa, Antonio; Radax, Christian; Ihara, Kunio; White, Melisa R; Stan-Lotter, Helga

    2009-08-01

    Three halophilic isolates, strains Halo-G*T, AUS-1 and Naxos II, were compared. Halo-G* was isolated from an evaporitic salt crystal from Baja California, Mexico, whereas AUS-1 and Naxos II were isolated from salt pools in Western Australia and the Greek island of Naxos, respectively. Halo-G*T had been exposed previously to conditions of outer space and survived 2 weeks on the Biopan facility. Chemotaxonomic and molecular comparisons suggested high similarity between the three strains. Phylogenetic analysis based on the 16S rRNA gene sequences revealed that the strains clustered with Halorubrum species, showing sequence similarities of 99.2-97.1%. The DNA-DNA hybridization values of strain Halo-G*T and strains AUS-1 and Naxos II are 73 and 75%, respectively, indicating that they constitute a single species. The DNA relatedness between strain Halo-G*T and the type strains of 13 closely related species of the genus Halorubrum ranged from 39 to 2%, suggesting that the three isolates constitute a different genospecies. The G+C content of the DNA of the three strains was 65.5-66.5 mol%. All three strains contained C20C20 derivatives of diethers of phosphatidylglycerol, phosphatidylglyceromethylphosphate and phosphatidylglycerolsulfate, together with a sulfated glycolipid. On the basis of these results, a novel species that includes the three strains is proposed, with the name Halorubrum chaoviator sp. nov. The type strain is strain Halo-G*T (=DSM 19316T=NCIMB 14426T=ATCC BAA-1602T). PMID:19567575

  8. Core Needle Biopsy Is a More Conclusive Follow-up Method Than Repeat Fine Needle Aspiration for Thyroid Nodules with Initially Inconclusive Results: A Systematic Review and Meta-Analysis

    PubMed Central

    Pyo, Jung-Soo; Sohn, Jin Hee; Kang, Guhyun

    2016-01-01

    Background: This study investigated the appropriate management of thyroid nodules with prior non-diagnostic or atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) through a systematic review and meta-analysis. Methods: This study included 4,235 thyroid nodules from 26 eligible studies. We investigated the conclusive rate of follow-up core needle biopsy (CNB) or repeat fine needle aspiration (rFNA) after initial fine needle aspiration (FNA) with non-diagnostic or AUS/FLUS results. A diagnostic test accuracy (DTA) review was performed to determine the diagnostic role of the follow-up CNB and to calculate the area under the curve (AUC) on the summary receiver operating characteristic (SROC) curve. Results: The conclusive rates of follow-up CNB and rFNA after initial FNA were 0.879 (95% confidence interval [CI], 0.801 to 0.929) and 0.684 (95% CI, 0.627 to 0.736), respectively. In comparison of the odds ratios of CNB and rFNA, CNB had more frequent conclusive results than rFNA (odds ratio, 5.707; 95% CI, 2.530 to 12.875). Upon subgroup analysis, follow-up CNB showed a higher conclusive rate than rFNA in both initial non-diagnostic and AUS/FLUS subgroups. In DTA review of followup CNB, the pooled sensitivity and specificity were 0.94 (95% CI, 0.88 to 0.97) and 0.88 (95% CI, 0.84 to 0.91), respectively. The AUC for the SROC curve was 0.981, nearing 1. Conclusions: Our results show that CNB has a higher conclusive rate than rFNA when the initial FNA produced inconclusive results. Further prospective studies with more detailed criteria are necessary before follow-up CNB can be applied in daily practice. PMID:27077724

  9. Combined use of conventional smear and liquid-based preparation versus conventional smear for thyroid fine-needle aspiration.

    PubMed

    Kim, Soo-Yeon; Kim, Eun-Kyung; Moon, Hee Jung; Yoon, Jung Hyun; Kwon, Hyeong Ju; Song, Mi Kyung; Kwak, Jin Young

    2016-07-01

    The purpose of the study was to compare the diagnostic utility of the combined conventional smear (CS) and liquid-based preparation (LBP) compared to CS with respect to the non-diagnostic rate, the atypia of undetermined significance (AUS) or follicular lesion of undetermined significance (FLUS) rate, and the diagnostic performances for malignancy. This retrospective study was approved by the Institutional Review Board, and the need to obtain informed consent was waived. In our institution, thyroid FNAs were processed with CS before October 2012, and LBP has been used in combination with CS after October 2012. On-site evaluation for the adequacy of CS was not performed. This study included nodules 5 mm or larger with FNAs performed by faculties: 811 nodules in 773 patients for CS, and 926 nodules in 894 patients for combined CS and LBP. Nodules with surgery or either benign or malignancy cytology on initial or repeat FNA were regarded to have the reference standards needed to calculate diagnostic performances. The proportion of Bethesda categories and diagnostic performances were compared between the two groups with z test. The non-diagnostic rate, the AUS or FLUS rate, and the diagnostic performances for malignancy were similar (All P > 0.05). The follicular neoplasm (FN) or suspicious for FN rate decreased from 1.2 to 0.3 % (P = 0.034). The benign rate increased from 51.4 to 57.0 % (P = 0.019). Combined CS and LBP decreased FN or suspicious for FN diagnoses, and increased benign diagnoses compared to CS with comparable non-diagnostic rates and AUS or FLUS rates, and comparable diagnostic performances. PMID:26714459

  10. Vom Urknall zum Durchknall

    NASA Astrophysics Data System (ADS)

    Unzicker, Alexander

    Lautstarker Applaus erhob sich im Salon III/IV des Marriott-Hotels von Crystal City im amerikanischen Bundesstaat Virginia. In dem überfüllten Konferenzraum starrten alle wie gebannt auf die Leinwand, wo nicht mehr zu sehen war als ein nüchternes Diagramm aus zahlreichen Punkten und einer geschwungenen Kurve. Nureine eigenartige Personengruppe konnte sich davon zu Emotionen hinreißen lassen - Physiker auf der Jahrestagung der Astronomischen Gesellschaft, die ihren Begeisterungssturm noch minutenlang fortsetzten. Was war geschehen? Die im Diagramm aufgetragenen Daten bestätigten mit einer nie da gewesenen Genauigkeit ein fundamentales Naturgesetz zur Wärmeabstrahlung von heißen Körpern. 1900 von Max Planck entdeckt, leuchtete es nun in geradezu mathematischer Reinheit auf. Noch sensationeller war der Ursprung der Daten - Mikrowellensignale verschiedener Frequenzen, die nicht aus einem irdischen Labor stammten, sondern von einem heißen Urzustand des Universums! Ein Feuerball aus Wasserstoff und Helium, noch ohne jegliche Strukturen, die irgendwann Leben ermöglichen sollten, ließ damals seinem Licht freien Lauf. Mehr als zehn Milliarden Jahre war es bis zu den Detektoren des vom Menschen gebauten Satelliten COBE unterwegs, der wenige Tage zuvor die Daten übertragen hatte. Wenn ich das alles wie einen Film in meiner Vorstellung ablaufen lasse, bekomme ich immer eine Gänsehaut, als würde ich die inzwischen extrem abgekühlte Strahlung tatsächlich spüren. Ihre Gleichverteilung im Raum macht uns auch deutlich, dass wir uns nicht einbilden dürfen, an einem besonderen Ort im Universum zu leben - intelligente Aliens könnten sich seitdem überall entwickelt haben! Sollten sie - was nicht wahrscheinlich ist - uns wirklich von Zeit zu Zeit über die Schulter schauen, dann hätten sie an jenem Nachmittag des 13. Januar 1990, als der Vortrag stattfand, bestimmt anerkennend mit ihrem großen Kopf genickt.

  11. Die Welt des Herrn Kuhn

    NASA Astrophysics Data System (ADS)

    Kern, Daniela

    Eines Morgens erwachte Herr Kuhn fröstelnd und staunte darüber, dass es in seinerWohnung eiskalt war. Dennoch quälte er sich aus seiner kuscheligen Bettdecke heraus und schlurfte ins Bad. "Hoffentlich wird wenigstens das Wasser warm", dachte er sich, als er den Wasserhahn betätigte - aber es kam nicht nur kein warmesWasser, außer einem unheilvollen Gluckser kam gar nichts aus der Leitung. "Dann werde ich wohl mal den Klempner anrufen", sprach er sich leise in den Bart und griff zu seinem Handy - doch das Netz war tot! Herr Kuhn begann nun, sich ernsthaft Sorgen zu machen, "Oje, was ist denn heute nur los? Ist irgendetwas Schlimmes passiert?" Um einen besseren Überblick über die Lage zu bekommen und sich austauschen zu können, brannte er nun förmlich darauf, rauszugehen und zur Arbeit zu fahren. An anderen Tagen, die er frisch geduscht und mit Kaffee und Marmeladen-Brot begann, war er selten so motiviert. So ging er also nun mit leerem Magen aus dem Haus. Hätte er den Versuch unternommen, sein tägliches Marmeladenbrot zuzubereiten, und dafür den Kühlschrank geöffnet, um das Marmeladenglas herauszunehmen, wäre ihm aufgefallen, dass auch die Stromversorgung Störungen unterworfen war, unschön zu erkennen an den ersten grünen, felligen Inseln auf seinem Lieblingskäse.

  12. Diagnostic value of BRAFV600E-mutation analysis in fine-needle aspiration of thyroid nodules: a meta-analysis

    PubMed Central

    Su, Xingyun; Jiang, Xiaoxia; Xu, Xin; Wang, Weibin; Teng, Xiaodong; Shao, Anwen; Teng, Lisong

    2016-01-01

    Fine-needle aspiration (FNA) is a reliable method for preoperative diagnosis of thyroid nodules; however, about 10%–40% nodules are classified as indeterminate. The BRAFV600E mutation is the most promising marker for thyroid FNA. This meta-analysis was conducted to investigate the diagnostic value of BRAFV600E analysis in thyroid FNA, especially the indeterminate cases. Systematic searches were performed in PubMed, Web of Science, Scopus, Ovid, Elsevier, and the Cochrane Library databases for relevant studies prior to June 2015, and a total of 88 studies were ultimately included in this meta-analysis. Compared with FNA cytology, the synergism of BRAFV600E testing increased the diagnostic sensitivity from 81.4% to 87.4% and decreased the false-negative rate from 8% to 5.2%. In the indeterminate group, the mutation rate of BRAFV600E was 23% and varied in different subcategories (43.2% in suspicious for malignant cells [SMC], 13.77% in atypia of undetermined significance/follicular lesion of undetermined significance [AUS/FLUS], and 4.43% in follicular neoplasm/suspicious for follicular neoplasm [FN/SFN]). The sensitivity of BRAFV600E analysis was higher in SMC than that in AUS/FLUS and FN/SFN cases (59.4% vs 40.1% vs 19.5% respectively), while specificity was opposite (86.1% vs 99.5% vs 99.7% respectively). The areas under the summary receiver-operating characteristic curve also confirmed the diagnostic value of BRAFV600E testing in SMC and AUS/FLUS rather than FN/SFN cases. Therefore, BRAFV600E analysis can improve the diagnostic accuracy of thyroid FNA, especially indeterminate cases classified as SMC, and select malignancy to guide the extent of surgery. PMID:27175084

  13. Halorubrum chaoviator sp. nov., a haloarchaeon isolated from sea salt in Baja California, Mexico, Western Australia and Naxos, Greece

    PubMed Central

    Mancinelli, Rocco L.; Landheim, Ragnhild; Sanchez-Porro, Cristina; Dornmayr-Pfaffenhuemer, Marion; Gruber, Claudia; Legat, Andrea; Ventosa, Antonio; Radax, Christian; Ihara, Kunio; White, Melisa R.; Stan-Lotter, Helga

    2011-01-01

    Three halophilic isolates, strains Halo-G*T, AUS-1 and Naxos II, were compared. Halo-G* was isolated from an evaporitic salt crystal from Baja California, Mexico, whereas AUS-1 and Naxos II were isolated from salt pools in Western Australia and the Greek island of Naxos, respectively. Halo-G*T had been exposed previously to conditions of outer space and survived 2 weeks on the Biopan facility. Chemotaxonomic and molecular comparisons suggested high similarity between the three strains. Phylogenetic analysis based on the 16S rRNA gene sequences revealed that the strains clustered with Halorubrum species, showing sequence similarities of 99.2–97.1 %. The DNA–DNA hybridization values of strain Halo-G*T and strains AUS-1 and Naxos II are 73 and 75 %, respectively, indicating that they constitute a single species. The DNA relatedness between strain Halo-G*T and the type strains of 13 closely related species of the genus Halorubrum ranged from 39 to 2 %, suggesting that the three isolates constitute a different genospecies. The G+C content of the DNA of the three strains was 65.5–66.5 mol%. All three strains contained C20C20 derivatives of diethers of phosphatidylglycerol, phosphatidylglyceromethylphosphate and phosphatidylglycerolsulfate, together with a sulfated glycolipid. On the basis of these results, a novel species that includes the three strains is proposed, with the name Halorubrum chaoviator sp. nov. The type strain is strain Halo-G*T (=DSM 19316T =NCIMB 14426T =ATCC BAA-1602T). PMID:19567575

  14. Aurone synthase is a catechol oxidase with hydroxylase activity and provides insights into the mechanism of plant polyphenol oxidases.

    PubMed

    Molitor, Christian; Mauracher, Stephan Gerhard; Rompel, Annette

    2016-03-29

    Tyrosinases and catechol oxidases belong to the family of polyphenol oxidases (PPOs). Tyrosinases catalyze theo-hydroxylation and oxidation of phenolic compounds, whereas catechol oxidases were so far defined to lack the hydroxylation activity and catalyze solely the oxidation of o-diphenolic compounds. Aurone synthase from Coreopsis grandiflora (AUS1) is a specialized plant PPO involved in the anabolic pathway of aurones. We present, to our knowledge, the first crystal structures of a latent plant PPO, its mature active and inactive form, caused by a sulfation of a copper binding histidine. Analysis of the latent proenzyme's interface between the shielding C-terminal domain and the main core provides insights into its activation mechanisms. As AUS1 did not accept common tyrosinase substrates (tyrosine and tyramine), the enzyme is classified as a catechol oxidase. However, AUS1 showed hydroxylase activity toward its natural substrate (isoliquiritigenin), revealing that the hydroxylase activity is not correlated with the acceptance of common tyrosinase substrates. Therefore, we propose that the hydroxylase reaction is a general functionality of PPOs. Molecular dynamics simulations of docked substrate-enzyme complexes were performed, and a key residue was identified that influences the plant PPO's acceptance or rejection of tyramine. Based on the evidenced hydroxylase activity and the interactions of specific residues with the substrates during the molecular dynamics simulations, a novel catalytic reaction mechanism for plant PPOs is proposed. The presented results strongly suggest that the physiological role of plant catechol oxidases were previously underestimated, as they might hydroxylate their--so far unknown--natural substrates in vivo. PMID:26976571

  15. Spontaneous gradual accumulation of hexagonally-aligned nano-silica on gold nanoparticles embedded in stabilized zirconia: a pathway from catalytic to NH3-sensing performance

    NASA Astrophysics Data System (ADS)

    Plashnitsa, Vladimir V.; Elumalai, Perumal; Fujio, Yuki; Kawaguchi, Toshikazu; Miura, Norio

    2011-05-01

    The present study highlights the influence of nano-impurities on the catalytic/sensing performance of nano-structured Au sensing-electrodes (SEs) housed in a quartz reactor and operated at high temperature over a long period of time. The planar sensor, made from a nano-structured Au-SE on a polished-polycrystalline (pp) yttria-stabilized zirconia (YSZ) substrate exhibited initially negligible electromotive force (emf) response to each of the examined gases (CO, CH4, C3H8, C3H6, NOx and NH3; 400 ppm each) at 700 °C in the presence of 5 vol.% oxygen and 5 vol.% water vapor. Such a poor emf response was attributed to the excellent gas-phase oxidation/reduction ability of Au nanoparticles embedded in the YSZ substrate at high temperature. The response of the planar sensor made up of nano-structured Au-SE was monitored for about 75 days at 700 °C. As a result of this long-term monitoring, we detected the appearance of highly sensitive and selective NH3 gas-sensing properties after 45-75 days of sensor operation. Detailed observation of the morphology and composition of the as-fabricated nano-structured Au-SE after 75 days operation at 700 °C revealed the gradual accumulation of hexagonally-aligned SiO2 nano-impurities on the surface of the Au nanoparticles. The NH3 sensing mechanism of the YSZ-based sensor using the spontaneously-formed composite (nano-Au + nano-SiO2)-SE is therefore proposed to be based on a strong acid-base interaction between gaseous NH3 and SiO2 nano-impurities, followed by spillover of adsorbed NH3 towards the nano-Au/pp-YSZ interface.

  16. Aurone synthase is a catechol oxidase with hydroxylase activity and provides insights into the mechanism of plant polyphenol oxidases

    PubMed Central

    Molitor, Christian; Mauracher, Stephan Gerhard

    2016-01-01

    Tyrosinases and catechol oxidases belong to the family of polyphenol oxidases (PPOs). Tyrosinases catalyze the o-hydroxylation and oxidation of phenolic compounds, whereas catechol oxidases were so far defined to lack the hydroxylation activity and catalyze solely the oxidation of o-diphenolic compounds. Aurone synthase from Coreopsis grandiflora (AUS1) is a specialized plant PPO involved in the anabolic pathway of aurones. We present, to our knowledge, the first crystal structures of a latent plant PPO, its mature active and inactive form, caused by a sulfation of a copper binding histidine. Analysis of the latent proenzyme’s interface between the shielding C-terminal domain and the main core provides insights into its activation mechanisms. As AUS1 did not accept common tyrosinase substrates (tyrosine and tyramine), the enzyme is classified as a catechol oxidase. However, AUS1 showed hydroxylase activity toward its natural substrate (isoliquiritigenin), revealing that the hydroxylase activity is not correlated with the acceptance of common tyrosinase substrates. Therefore, we propose that the hydroxylase reaction is a general functionality of PPOs. Molecular dynamics simulations of docked substrate–enzyme complexes were performed, and a key residue was identified that influences the plant PPO’s acceptance or rejection of tyramine. Based on the evidenced hydroxylase activity and the interactions of specific residues with the substrates during the molecular dynamics simulations, a novel catalytic reaction mechanism for plant PPOs is proposed. The presented results strongly suggest that the physiological role of plant catechol oxidases were previously underestimated, as they might hydroxylate their—so far unknown—natural substrates in vivo. PMID:26976571

  17. Carl Friedrich Gauss - General Theory of Terrestrial Magnetism - a revised translation of the German text

    NASA Astrophysics Data System (ADS)

    Glassmeier, K.-H.; Tsurutani, B. T.

    2014-02-01

    This is a translation of the Allgemeine Theorie des Erdmagnetismus published by Carl Friedrich Gauss in 1839 in the Resultate aus den Beobachtungen des Magnetischen Vereins im Jahre 1838. The current translation is based on an earlier translation by Elizabeth Juliana Sabine published in 1841. This earlier translation has been revised, corrected, and extended. Numerous biographical comments on the scientists named in the original text have been added as well as further information on the observational material used by Carl Friedrich Gauss. An attempt is made to provide a readable text to a wider scientific community, a text laying the foundation of today's understanding of planetary magnetic fields.

  18. The CSM testbed matrix processors internal logic and dataflow descriptions

    NASA Technical Reports Server (NTRS)

    Regelbrugge, Marc E.; Wright, Mary A.

    1988-01-01

    This report constitutes the final report for subtask 1 of Task 5 of NASA Contract NAS1-18444, Computational Structural Mechanics (CSM) Research. This report contains a detailed description of the coded workings of selected CSM Testbed matrix processors (i.e., TOPO, K, INV, SSOL) and of the arithmetic utility processor AUS. These processors and the current sparse matrix data structures are studied and documented. Items examined include: details of the data structures, interdependence of data structures, data-blocking logic in the data structures, processor data flow and architecture, and processor algorithmic logic flow.

  19. Optionsbewertung

    NASA Astrophysics Data System (ADS)

    Schoenmakers, John

    Seitdem es auf dieser Welt Geld gibt, wird damit gerechnet. Mathematik und Geld sind von daher eng miteinander verknüpft. Dabei sind die Anforderungen an die Rechenkünste gestiegen: Das Einmaleins reicht längst nicht mehr aus, schon gar nicht, wenn es um die Bewertung von Portfolios und komplizierten Finanzkonstrukten (Derivaten) geht. Mathematiker helfen der Finanzindustrie und arbeiten eng mit Banken und Versicherungen zusammen. Sie entwickeln Modelle und Programme, mit denen sich mittels mathematischer Verfahren Risiken und Absicherungsstrategien kompliziert strukturierter Finanzprodukte besser einschätzen lassen.

  20. Von Ringplaneten und schwarzen Löchern. Die Top-Themen der Astronomie

    NASA Astrophysics Data System (ADS)

    Keller, Hans-Ulrich

    Die spannendsten Monatsthemen der letzten Jahre. Wie alt ist das Universum? Woher kommen die Sterne? Beeinflusst der Mond das irdische Leben? Fast jeder mag sich diese und ähnliche Fragen schon einmal gestellt haben. Kurzweilig berichtet Hans-Ulrich Keller von alten Weisheiten und neuen Erkenntnissen aus der Wissenschaft. Mit vielen farbigen Bildern und Illustrationen sind diese "astronomischen Kurzgeschichten" Lesevergnügen und Informationsquelle zugleich. In über 20 Artikeln erfahren Sie z. B. etwas über: Das feurige Schicksal unseres Sonnensystems. Das Rätsel der dunklen Materie. Die Suche nach außerirdischen Intelligenzen.

  1. Sitzungsberichte der Heidelberger Akademie der Wissenschaften> " Jahrgang 1990 Sitzungsber.Heidelberg 90 " "Gott hat die Natur einfältig gemacht, sie aber suchen viel Künste"

    NASA Astrophysics Data System (ADS)

    Zehe, Horst

    Der Aufsatz demonstriert anhand ausgiebig kommentierter zeitgenössischer Zeugnisse Goethes Reaktion auf die Arbeiten Fraunhofers, insbesondere auf die Entdeckung der dunklen Linien im Sonnenspektrum. Den Fehlurteilen Goethes werden dabei die Urteile zeitgenössischer Physiker wie Chladni und J.F.W. Herschel gegenübergestellt. Bislang noch ungedruckte Dokumente aus dem Weimarer Goethe- und Schiller-Archiv belegen, daß sich Goethe nicht nur literarisch mit Fraunhofer beschäftigte, sondern daß er auch dessen Versuche mit Hilfe des Jenaer Universitätsmechanikers Körner getreulich zu wiederholen suchte.

  2. Sitzungsberichte der Heidelberger Akademie der Wissenschaften¬Jahrgang 1990 Sitzungsber.Heidelberg 90¬"Gott hat die Natur einfältig gemacht, sie aber suchen viel Künste"

    NASA Astrophysics Data System (ADS)

    Zehe, Horst

    Der Aufsatz demonstriert anhand ausgiebig kommentierter zeitgenössischer Zeugnisse Goethes Reaktion auf die Arbeiten Fraunhofers, insbesondere auf die Entdeckung der dunklen Linien im Sonnenspektrum. Den Fehlurteilen Goethes werden dabei die Urteile zeitgenössischer Physiker wie Chladni und J.F.W. Herschel gegenübergestellt. Bislang noch ungedruckte Dokumente aus dem Weimarer Goethe- und Schiller-Archiv belegen, daß sich Goethe nicht nur literarisch mit Fraunhofer beschäftigte, sondern daß er auch dessen Versuche mit Hilfe des Jenaer Universitätsmechanikers Körner getreulich zu wiederholen suchte.

  3. Terror mit Atomwaffen: reale Gefahr? Nukleare und Radiologische Waffen

    NASA Astrophysics Data System (ADS)

    Harigel, Gert G.

    2006-01-01

    Können Terroristen sich nukleare Massenvernichtungswaffen beschaffen? Dazu müssten sie ausreichende Mengen an waffenfähigem, spaltbarem Material stehlen. Selbst der Bau einer primitiven Atombombe erfordert einen hohen technischen Aufwand und Spezialisten. Wahrscheinlicher ist deshalb der Diebstahl einer kleinen taktischen Kernwaffe. Alternativ könnten Terroristen sich radioaktives Material aus zivilen Quellen beschaffen und daraus eine Schmutzige Bombe bauen. Eine solche radiologische Waffe wäre keine echte Massenvernichtungswaffe, doch ihre psychologische Wirkung könnte stark sein. Das macht sie für Terroristen attraktiv, weswegen diese Gefahr ernst genommen werden muss.

  4. A modified form of conjugate gradient method for unconstrained optimization problems

    NASA Astrophysics Data System (ADS)

    Ghani, Nur Hamizah Abdul; Rivaie, Mohd.; Mamat, Mustafa

    2016-06-01

    Conjugate gradient (CG) methods have been recognized as an interesting technique to solve optimization problems, due to the numerical efficiency, simplicity and low memory requirements. In this paper, we propose a new CG method based on the study of Rivaie et al. [7] (Comparative study of conjugate gradient coefficient for unconstrained Optimization, Aus. J. Bas. Appl. Sci. 5(2011) 947-951). Then, we show that our method satisfies sufficient descent condition and converges globally with exact line search. Numerical results show that our proposed method is efficient for given standard test problems, compare to other existing CG methods.

  5. Limits of quantitation - Yet another suggestion

    NASA Astrophysics Data System (ADS)

    Carlson, Jill; Wysoczanski, Artur; Voigtman, Edward

    2014-06-01

    The work presented herein suggests that the limit of quantitation concept may be rendered substantially less ambiguous and ultimately more useful as a figure of merit by basing it upon the significant figure and relative measurement error ideas due to Coleman, Auses and Gram, coupled with the correct instantiation of Currie's detection limit methodology. Simple theoretical results are presented for a linear, univariate chemical measurement system with homoscedastic Gaussian noise, and these are tested against both Monte Carlo computer simulations and laser-excited molecular fluorescence experimental results. Good agreement among experiment, theory and simulation is obtained and an easy extension to linearly heteroscedastic Gaussian noise is also outlined.

  6. The influence of gold(i) on the mechanism of thiolate, disulfide exchange.

    PubMed

    Garusinghe, Gamage S P; Bessey, S Max; Bruce, Alice E; Bruce, Mitchell R M

    2016-07-28

    The mechanism of gold(i)-thiolate, disulfide exchange was investigated by using initial-rate kinetic studies, 2D ((1)H-(1)H) ROESY NMR spectroscopy, and electrochemical/chemical techniques. The rate law for exchange is overall second order, first order in gold(i)-thiolate and disulfide. 2D NMR experiments show evidence of association between gold(i)-thiolate and disulfide. Electrochemical/chemical investigations do not show evidence of free thiolate and are consistent with a mechanism involving formation of a [Au-S, S-S], four-centered metallacycle intermediate during gold(i)-thiolate, disulfide exchange. PMID:27353236

  7. Doktor Johannes Häringshauser - Was seine Bücher über ihn erzählen.

    NASA Astrophysics Data System (ADS)

    Feola, Vittoria

    2009-06-01

    Die Bibliothek des Dr. Johannes Häringshauser (1603-1642) weist ihren Besitzer als Arzt und Gelehrten mit großem geistigen Horizont aus. Hervorzuheben ist sein Interesse für Astronomie und Astrologie. Neben Werken, die unmittelbar mit seinen Studien in Wien und Padua und den Erfordernissen eines Arztes in Zusammenhang zu bringen sind (Klassiker der Heilkunde genauso wie aktuelle medizinische Publikationen), wird in seiner Büchersammlung eine reiche Palette an Themen abgedeckt: Theologie, Philosophie, Philologie, Politik, Geschichte und Länderkunde.

  8. Anbindung des SISIS-SunRise-Bibliothekssystems an das zentrale Identitätsmanagement

    NASA Astrophysics Data System (ADS)

    Ebner, Ralf; Pretz, Edwin

    Wir berichten über Konzepte und Implementierungen zur Datenprovisionierung aus den Personenverwaltungssystemen der Technischen Universität München (TUM) über das zentrale Metadirectory am Leibniz-Rechenzentrum (LRZ) in das SISIS-SunRise-Bibliothekssystem der Universitätsbibliothek der TUM (TUB). Es werden drei Implementierungsvarianten diskutiert, angefangen von der Generierung und Übertragung einfacher CSV-Dateien über ein OpenLDAP-basiertes Konzept als Backend für die SISIS-Datenbank bis zur endgültigen Implementierung mit dem OCLC IDM Connector.

  9. Validation of the Extend Suite of MOD09 and SMAC Processed Reflectance Products for Australian Terrestrial Supersites: A Case Study

    NASA Astrophysics Data System (ADS)

    Broomhall, M. A.; Chedzey, H. C.; McAtee, B.; Fearns, P.; Lynch, M. J.

    2014-12-01

    The Australian Terrestrial Ecosystem Research Network (TERN) brings together ecosystem scientists allowing them to collect, contribute, store, integrate data and collaborate across numerous disciplines. The TERN AusCover Facility comprises a national expert network that provides remote sensing data such as satellite-derive biophysical products, advanced remote sensing products and ground-validation information free and online to the research community. TERN and AusCover have collected in situ data for a number of 5 km x 5 km supersites from nearly every state and territory in Australia. These data include spectrophotometer data, sun photometer and ozonometer data, airborne and terrestrial LIDAR data and airborne hyperspectral data. As part of the AusCover facility and in conjunction with Landgate, Western Australia, Curtin University has modified the atmospheric correction and surface reflectance processing scheme from Landgate to process 12 extra MODIS bands to surface reflectance, thus providing 19 bands. This processing scheme uses the Simple Method for Atmospheric Correction (SMAC) to produce reflectance data. Until recently, only the first 7 MODIS bands were available with the MODIS institutional algorithm for surface reflectance, MOD09, but this has altered to now also provide 9 extra bands. MOD09 is based around 6S to produce reflectance data. This case study makes use of hyperspectral airborne data captured over the Credo TERN supersite to compare the surface reflectance products from MOD09 and the SMAC-based 19-band reflectance process. This work required validating the airborne data against a set in situ reflectance measurements of large calibration targets. The validated airborne data were resampled spatially and spectrally to MODIS bands and both the airborne and MODIS data were mapped to the same spatial grid. Direct pixel comparisons have been made between the airborne data and the two algorithms, and between the algorithms themselves. The algorithms

  10. Detection of interstellar pick-up hydrogen in the solar system

    NASA Technical Reports Server (NTRS)

    Gloeckler, G.; Geiss, J.; Balsiger, H.; Fisk, L. A.; Galvin, A. B.; Ipavich, F. M.; Ogilvie, K. W.; Von Steiger, R.; Wilken, B.

    1993-01-01

    Interstellar hydrogen ionized primarily by the solar wind has been detected by the Solar Wind Ion Composition Spectrometer instrument on the Ulysses spacecraft at a distance of 4.8 AUs from the sun. This 'pick-up' hydrogen is identified by its distinct velocity distribution function, which drops abruptly at twice the local solar wind speed. From the measured fluxes of pick-up protons and singly charged helium, the number densities of neutral hydrogen and helium in the distant regions of the solar system are estimated to be 0.077 +/- 0.015 and 0.013 +/- 0.003 per cu cm, respectively.

  11. XAFS study on structural order in highly monodispersed thiol-stabilized Au nanoparticles

    NASA Astrophysics Data System (ADS)

    Huang, Y.; Liu, W.; Yang, L.; Huang, T.; Jiang, Y.; Yao, T.; Wei, S.

    2016-05-01

    Understanding the influence of thiol on nanoparticle size and structure is essential for the fundamental and applied researches. Here, using x-ray absorption fine structure (XAFS) spectroscopy, we investigate the structural order of Au nanoparticles (NPs) in the protection of thiol ligands with different contents. We found that besides protecting Au NPs against aggregation and growth, thiolates can effectively eliminate the dangling bonds of unsaturated Au atoms, and thus increase the structural order. This work enriches our knowledge of Au-S interface interaction and guides the way towards preparing size-controllable nanoparticles with specific physical/chemical properties.

  12. Nanomechanics of bidentate thiolate ligands on gold surfaces.

    PubMed

    Zoloff Michoff, Martin E; Ribas-Arino, Jordi; Marx, Dominik

    2015-02-20

    The effect of the chain length separating sulfur atoms in bidentate thiols attached to defective gold surfaces on the rupture of the respective molecule-gold junctions has been studied computationally. Thermal desorption always yields cyclic disulfides. In contrast, mechanochemical desorption leads to cyclic gold complexes, where metal atoms are extracted from the surface and kept in tweezer-like arrangements by the sulfur atoms. This phenomenon is rationalized in terms of directional mechanical manipulation of Au-Au bonds and Au-S coordination numbers. Moreover, the flexibility of the chain is shown to crucially impact on the mechanical strength of the junction. PMID:25763962

  13. Keller oder Dach zuerst?

    NASA Astrophysics Data System (ADS)

    Megow, Nicole

    Komplexe Planungsaufgaben entstehen in vielen Bereichen wie z. B. in der Produktion und Logistik, der Bauplanung oder allgemein im Projektmanagement. Typischerweise werden umfangreiche Projekte in viele einzelne Teilaufgaben zerlegt, die dann zeitlich geplant werden. Das heißt, es wird genau bestimmt wann bzw. in welcher Reihenfolge Aufgaben mit welchen Ressourcen durchgeführt warden sollen. Bei der Planung müssen verschiedenste Reihenfolgeabhängigkeiten zwischen den Vorgängen berücksichtigt werden. Diese Abhängigkeiten können technischer Natur sein oder werden aus sicherheitsrelevanten oder wirtschaftlichen Gründen festgelegt.

  14. Geschichtlicher Überblick

    NASA Astrophysics Data System (ADS)

    Bölke, Klaus-Peter

    Die Nachweise einer schadlosen Ableitung von Abwässern lassen sich bis weit in die Vergangenheit zurückverfolgen. Sie waren bereits zur damaligen Zeit eine Forderung zur Pflege der öffentlichen Reinlichkeit. Der Kanalisationsbau ist auch immer ein Ausdruck der Kultur eines Volkes gewesen. So kann festgestellt werden, dass im Zusammenhang mit der Hochkultur eines Volkes auch der Kanalbau ein vorherrschendes Thema war. Der Kanalbau steht auch in einem engen Zusammenhang mit dem Wasserleitungsbau. Es ist nur logisch, dass dort wo Wasser teilweise aus großer Entfernung herangeführt worden ist, dieses dann nach Gebrauch auch wieder schadlos beseitigt werden musste.

  15. VLBI Water Maser Proper Motion Measurements in Star-Forming Regions

    NASA Astrophysics Data System (ADS)

    Torrelles, J. M.; Patel, N.; Gómez, J. F.; Anglada, G.; Uscanga, L.

    We review some of the recent water maser proper motion measurements in star-forming regions performed through VLBI multi-epoch observations. These observations are starting to reveal exciting perspectives, providing the full kinematics of the gas within the outflows/circumstellar disks around YSOs at scales of AUs, discovering new phenomena (e.g., isotropic mass ejections, watermaser "micro-structures" exhibiting remarkable coherent and well ordered spatio-kinematical behavior at AU scale), and opening new, puzzling questions related to the early stellar evolution.

  16. Vlbi Water Maser Proper Motion Measurements in Star-Forming Regions

    NASA Astrophysics Data System (ADS)

    Torrelles, J. M.; Patel, N.; Gómez, J. F.; Anglada, G.; Uscanga, L.

    2005-01-01

    We review some of the recent water maser proper motion measurements in star-forming regions performed through VLBI multi-epoch observations. These observations are starting to reveal exciting perspectives, providing the full kinematics of the gas within the outflows/circumstellar disks around YSOs at scales of AUs, discovering new phenomena (e.g., isotropic mass ejections, water maser "micro-structures" exhibiting remarkable coherent and well ordered spatio-kinematical behavior at AU scale), and opening new, puzzling questions related to the early stellar evolution.

  17. Sandsturm kontra Wassersturm: Physik im Alltag

    NASA Astrophysics Data System (ADS)

    Müller, Andreas

    2006-07-01

    Sandstürme ereignen sich oft, Wasserstürme hingegen so gut wie nie. Eine Abschätzung zeigt, dass man beim Herauslösen eines Wassertropfens beispielsweise aus dem Meer eine sehr große Kraft benötigt und sehr viel Arbeit verrichten muss. Das scheint die Erklärung zu sein. Führt man eine entsprechende Energiebetrachtung durch, so könnte es durchaus Wasserstürme geben. Diese Überlegung ist zwar mathematisch richtig, aber unvollständig.

  18. Elektrotechnik

    NASA Astrophysics Data System (ADS)

    Böge, Gert

    Ursprünglicher Sitz der Elektrizität ist das Atom. Das Wasserstoffatom z.B. besteht aus einem Proton als Kern und einem Elektron, das diesen Kern auf einer bestimmten Bahn umkreist. Das Proton bezeichnet man als elektrisch positiv, - das Elektron als negativ geladen. Zwischen beiden befindet sich die "Elektrizität“ in Form eines besonderen Raumzustandes, der als elektrisches Feld bezeichnet wird. Normalerweise erscheint ein Stoff nach außen hin elektrisch neutral, weil ebenso viele positive wie negative Ladungen in ihm enthalten sind.

  19. Vom magnetischen Bakterium zur Brieftaube: Geo-Biomagnetismus

    NASA Astrophysics Data System (ADS)

    Winklhofer, Michael

    2004-05-01

    Die Fähigkeit, das Erdmagnetfeld wahrzunehmen und sich an ihm zu orientieren, ist im Tierreich weit verbreitet. Durch welche physikalischen Mechanismen magnetische Sinnesreize in Nervensignale umgesetzt werden, ist jedoch weitgehend ungeklärt. Bei magnetotaktischen Bakterien üben zum Beispiel biogene ferrimagnetische Kristalle als mikroskopische Kompassnadeln ein Drehmoment auf die Zelle aus. Magnetit findet sich im Gewebe zahlreicher Tiere. Doch erst bei zwei Arten, der Brieftaube und der Regenbogenforelle, konnten auch entsprechende Sinneszellen gefunden werden. Diese unterscheiden sich allerdings in ihren magnetischen Eigenschaften fundamental voneinander. Die Identifizierung der physikalischen Mechanismen des Geo-Biomagnetismus bleibt eine Herausforderung für Biophysik und Sinnesphysiologie.

  20. Herausforderungen durch die deutsche Wiedervereinigung

    NASA Astrophysics Data System (ADS)

    Stäglin, Reiner

    Die Wiedervereinigung stellte auch die Statistik vor große Aufgaben. Die als Organ der staatlichen Planung staatsnah orientierte Statistik der DDR musste auf das zur Neutralität und wissenschaftlichen Unabhängigkeit verpflichtete System der Bundesrepublik umgestellt werden. Ebenso verlangten die Universitäten eine Neuorientierung. Die Deutsche Statistische Gesellschaft hat sich vor allem dreier Aufgaben mit großem Engagement, aber auch mit Bedachtsamkeit angenommen: Aufnahme und Integration der Statistiker aus den neuen Bundesländern in die Gesellschaft, Begleitung der Neuausrichtung des Faches Statistik an deren Hochschulen und Sicherung sowie Nutzung von Datenbeständen der ehemaligen DDR.

  1. Kopf

    NASA Astrophysics Data System (ADS)

    Goldschmid, Alfred; Maier, Wolfgang; Olsson, Lennart; Piekarski, Nadine

    Die Evolution des Wirbeltierkopfes ist ein klassisches Problemfeld der vergleichend en Morphologie. Bereits J.W. von Goethe (1749-1832) und L. Oken (1779-1851) vertraten die Idee eines aus Segmenten bestehenden Schädels. Die Segmente sollten umgewandelten Wirbeln entsprechen; später wurden auch die Hirnnerven den segmentalen Spinalnerven des Rumpfes gleichgesetzt — Vorstellungen, die vor allem gegen Ende des 19. Jh. auf massive Ablehnung stießen. Die moderne Entwicklungsbiologie zei gt jedoch, dass zumindest Teile des Kopfes in ihrer Entwicklung eine deutliche Segmentierung aufweisen.

  2. Mathematik semantologisch verstehen

    NASA Astrophysics Data System (ADS)

    Wille, Rudolf

    Um zu verstehen, was Mathematik ist und bedeutet, reicht es nicht aus, mathematisches Denken und Wissen vielseitig zu erwerben. Hinzukommen muss stets ein angemessenes Verständnis der jeweiligen Bedeutungen mathematischer Denkformen, die in der aktual-realen Welt wirksam werden können. Beim Mathematik-Verstehen sollte es vor allem um ein Vermitteln des Selbstverständnisses der Mathematik, um ein Reflektieren des Bezugs der Mathematik zur realen Welt und um ein Beurteilen von Sinn, Bedeutung und Zusammenhang des Mathematischen in der Welt gehen.

  3. Durch Raum und Zeit reisen - Eine Theorie gibt Antworten auf alte Fragen

    NASA Astrophysics Data System (ADS)

    Sonne, Bernd; Weiß, Reinhard

    2013-07-01

    Im Rahmen der Relativitätstheorie, sei es die spezielle oder auch allgemeine, kommt man zwangsläufig auf die Fragestellung, ob Zeitreisen möglich sind oder nicht. Es gibt darüber sehr viele Veröffentlichungen, da dieses Thema offensichtlich viele Leute beschäftigt: Naturwissenschaftler, Philosophen, Filmautoren. Wir wollen hier nur einige grundlegende Fragestellungen aufgreifen: Kann man in die Zukunft reisen? Gibt es Reisen mit Überlichtgeschwindigkeit? Wie sieht es aus mit Reisen in die Vergangenheit? Wir unterschieden dabei zwischen mathematischen, physikalischen und technischen Lösungen, die Zeitreisen entweder erlauben oder unmöglich machen.

  4. Three Plate Reconstruction in the Eastern Indian Ocean: New Constraints on Wharton and Australian-Antarctic basins

    NASA Astrophysics Data System (ADS)

    Jacob, J.; Dyment, J.

    2012-12-01

    Understanding the continuous seismicity and repeated occurrence of major earthquakes in Sumatra and the neighboring area requires detailed constrains on the subducting plate. In this study we analyze the past plate kinematics evolution of the Wharton basin, eastern Indian Ocean through a three plate reconstruction involving Australia (AUS), Antarctica (ANT), and India (IND). We compile marine magnetic identifications in the Australian-Antarctic Basin [1,2], the Crozet and Central Indian basins (Yatheesh et al, in prep.) and the Wharton Basin [3]. The Wharton Basin is characterized by an extinct spreading center dated by anomaly 18 (38 Ma). The southern flank of the basin exhibits a continuous sequence of anomalies 20n (42 Ma) to 34n (84 Ma), whereas the northern flank lacks some of the older anomalies because a significant part has been subducted in the Sunda Trench. The three-plate reconstructions have provided set of rotation parameters describing the evolution of IND-AUS. Using these parameters, we have reconstructed the missing isochrons of the northern flank and the detailed geometry of the subducted part of the Wharton basin. Such an exercise provides useful constraints on the age and structure of the plate in subduction under Indonesia. As a byproduct, the three plate reconstruction provided set of rotation parameters for AUS-ANT as well, which constrains the conjugate fit between the basins. Previous studies [1,2,4,5] have achieved such a fit on the base of ill-defined fracture zones. We consider the well-defined fracture zones from the Crozet, Central Indian, and Wharton basins, but avoid using the poor fracture zone imprints from the Australian-Antarctic Basin. As a result from this approach, we conclude that the relative motion of AUS with respect to ANT initially followed a north-south direction, then changed to northwest-southeast at anomaly 32ny, and reverted to northeast southwest at anomaly 24no prior to the establishment of the Southeast Indian

  5. Real-time safety surveillance of seasonal influenza vaccines in children, Australia, 2015.

    PubMed

    Pillsbury, Alexis; Cashman, Patrick; Leeb, Alan; Regan, Annette; Westphal, Darren; Snelling, Tom; Blyth, Christopher; Crawford, Nigel; Wood, Nicholas; Macartney, Kristine

    2015-01-01

    Increased febrile reactions in Australian children from one influenza vaccine brand in 2010 diminished confidence in influenza immunisation, highlighting the need for improved vaccine safety surveillance. AusVaxSafety, a national vaccine safety surveillance system collected adverse events in young children for 2015 influenza vaccine brands in real time through parent/carer reports via SMS/email. Weekly cumulative data on 3,340 children demonstrated low rates of fever (4.4%) and medical attendance (1.1%). Fever was more frequent with concomitant vaccination. PMID:26536867

  6. Zuschauer beim Berlin-Marathon

    NASA Astrophysics Data System (ADS)

    Hougardy, Stefan; Kirchner, Stefan; Zelke, Mariano

    Jedes Computerprogramm, sei es ein Betriebssystem, eine Textverarbeitung oder ein Computerspiel, ist aus einer Vielzahl von Algorithmen zusammen gesetzt. Ein Algorithmus ist eine Art Rechenvorschrift, die Daten als Eingabe entgegennimmt und daraus ein Ergebnis berechnet. Um beispielsweise die Anzeige desMauszeigers auf dem Bildschirm zu steuern, erhält der dafür zuständige Algorithmus die letzte Position des Mauszeigers und die Bewegung der Maus auf dem Schreibtisch als Eingabe. Daraus wird die neue Position des Mauszeigers berechnet, sie bildet die Ausgabe des Algorithmus.

  7. The effect of heat treatment on the gouging abrasion resistance of alloy white cast irons

    NASA Astrophysics Data System (ADS)

    Are, I. R. S.; Arnold, B. K.

    1995-02-01

    A series of heat treatments was employed to vary the microstructure of four commercially important alloy white cast irons, the wear resistance of which was then assessed by the ASTM jaw-crusher gouging abrasion test. Compared with the as-cast condition, standard austenitizing treatments produced a substantial increase in hardness, a marked decrease in the retained aus-tenite content in the matrix, and, in general, a significant improvement in gouging abrasion resistance. The gouging abrasion resistance tended to decline with increasing austenitizing tem-perature, although the changes in hardness and retained austenite content varied, depending on alloy composition. Subcritical heat treatment at 500 ° following hardening reduced the retained austenite content to values less than 10 pct, and in three of the alloys it caused a significant fall in both hardness and gouging abrasion resistance. The net result of the heat treatments was the development of optimal gouging abrasion resistance at intermediate levels of retained aus-tenite. The differing responses of the alloys to both high-temperature austenitizing treatments and to subcritical heat treatments at 500 ° were related to the effects of the differing carbon and alloying-element concentrations on changes in the M s temperature and secondary carbide precipitation.

  8. Bewertung und Verbesserung der Zuverlässigkeit von mikroelektronischen Komponenten in mechatronischen Systemen

    NASA Astrophysics Data System (ADS)

    Wunderlich, Hans-Joachim; Elm, Melanie; Kochte, Michael

    In den letzten Jahrzehnten hat der Anteil der informationsverarbeitenden Komponenten an den Herstellungskosten mechatronischer Systeme rapide zugenommen. In den 70er Jahren machte die Informationsverarbeitung noch ca. 15% des Systems aus. Zu Beginn dieses Jahrtausends sind es bereits über 60% [8.9], wie auch aus Abb. 8.1 hervorgeht. Dieser Zuwachs in den Herstellungskosten ist auf die Zunahme der durch die Informationsverarbeitung realisierten Funktionen zurückzuführen. Sehr deutlich ist diese Zunahme im Automobil zu beobachten. Während das Antiblockiersystem und die digitale Motorsteuerung schon seit Jahren zum Standard gehören, werden nun zunehmend auch Fahrerassistenz- und Infotainmentsysteme ins Kraftfahrzeug integriert. Bei diesen Systemen beginnt die Grenze zwischen klassischer Sicherheits- und Komfortfunktion zu verschwimmen. Die Bandbreite möglichen Fehlverhaltens reicht vom Ausfall des Navigationssystems über Störungen der Zentralverriegelung bis hin zum automatischen Einleiten von Bremsmanövern bei hohen Geschwindigkeiten. Entsprechend ergeben sich hier hohe Anforderungen an die Zuverlässigkeit dieser Systeme.

  9. Über die Methode der physikalischen Naturbeschreibung [33

    NASA Astrophysics Data System (ADS)

    Wenn es zu den Aufgaben der Philosophie und der wissensehaftlicher Theologie gehört, das Warum und Wie unserer Existenz und ihrer Umwelt zu ergründen, so muss als ihr Ausgangspunkt eine vollständige und möglichst übersichtliche Beschreibung unserer Empfindungen vorliegen. Einen Teil dieser Empfindungen fassen wir unter dem Namen Sinnesempfindungen zusammen. Ob ein solcher Aussehnitt genau abgegrenzt werden kann, soll hier nicht untersucht werden. Es kann sogar mit gewisser Berechtigung behauptet werden, dass eine Unterteilung gar nicht streng durchführbar ist. Der schon in der Philosophie der Antike uns entgegentretende Gedanke, dass die Welt nur in ihrer Gesamtheit rerständlich sein kann, kommt sicherlich der Wahrheit näher als die philosophischen Systeme des verflossenen Jahrhunderts, welche glaubten, dass alies aus unseren materialistischen Erkenntnissen heraus erklärt werden könne. Die Entstehung dieser Systeme, ich denke z. Â. an den Monisimis Haeckels, erklärt sich aus der Hybris, welche die Reaktion der Philosophie auf die bedeutenden Erfolge der exakten Naturwissenschaften war. Die ebenfalls nicht zu imterschätzenden Fortschritte unserer heutigen Kenntnisse auf diesem Gebiete zwingen din Naturforschung eher zu einer immer steigenden Bescheidenheit den "Welträtseln" gegenüber, deren letzte Konsequenz vielleicht darin liegen wird, dass sie die eingangs der Philosophie und Theologie zugewiesene Aufgabe als unlosbar bezeichnen muss..

  10. Self-reported ability assessment in rock climbing.

    PubMed

    Draper, Nick; Dickson, Tabitha; Blackwell, Gavin; Fryer, Simon; Priestley, Sefton; Winter, David; Ellis, Greg

    2011-05-01

    Level of ability within rock climbing is generally expressed in terms of a "best ascent", rated using various grading systems within the sport. The most common method of obtaining this information is via self-report. The aim of this study was to examine the validity of self-reported climbing grades. Twenty-nine competitive rock climbers (17 males, 12 females) were first asked to report their current (defined as within the last 12 months) best on-sight lead ascent grade (Aus/NZ). The participants then climbed a specifically designed indoor route, under on-sight conditions (one attempt, no route practice or preview), to obtain an assessed grade. The route increased in difficulty, and was such that the distance achieved by the climber corresponded to a particular grade. The mean (±standard deviation) self-reported and assessed grade was 22.6 ± 3.4 and 22.0 ± 3.0 (Aus/NZ) respectively. Despite slight over- and underestimations in males and females respectively, there was no statistically significant difference between self-reported and assessed on-sight climbing grades. The results of this study suggest that self-reported climbing grades provide a valid and accurate reflection of climbing ability. PMID:21491325

  11. Herschel und die Zukunft der Fern-Infrarot-Astronomie

    NASA Astrophysics Data System (ADS)

    Linz, Hendrik

    2015-06-01

    Schon lange ist die beobachtende Astronomie den engen Grenzen des optisch Sichbaren entwachsen und hat fast alle Bereiche des elektromagnetischen Spektrums für sich dienstbar gemacht. Im sogenannten nahen und mittleren Infrarot (Wellenlängen zwischen 1-30 μm) sowie im Millimeter- und Radio-Regime (Wellenlängen zwischen 1 mm und 10 m) ist die Erdatmosphäre relativ gut durchlässig für elektromagnetische Signale oder hat zumindest eine Vielzahl von spektral begrenzten Transmissionsfenstern, die astronomische Beobachtungen zumindest von höheren Bergen aus möglich machen. Allerdings ist das sogenannte Ferne Infrarot (FIR, 30-300 μm Wellenlänge) von der Erde aus fast völlig unzugänglich für astronomische Beobachtungen. Selbst für die besten Beobachtungsplätze der Erde bleibt die atmosphärische Transmission durch die immense Wasserdampf- Absorption auf ein absolutes Minimum beschränkt. Jedoch erlaubt uns das FIR Zugang zu Informationen, die sehr nützlich sind für die astrophysikalische Forschung und komplementär zu anderen Wellenlängen-Bereichen.

  12. Reusable launch vehicles, enabling technology for the development of advanced upper stages and payloads

    SciTech Connect

    Metzger, John D.

    1998-01-15

    In the near future there will be classes of upper stages and payloads that will require initial operation at a high-earth orbit to reduce the probability of an inadvertent reentry that could result in a detrimental impact on humans and the biosphere. A nuclear propulsion system, such as was being developed under the Space Nuclear Thermal Propulsion (SNTP) Program, is an example of such a potential payload. This paper uses the results of a reusable launch vehicle (RLV) study to demonstrate the potential importance of a Reusable Launch Vehicle (RLV) to test and implement an advanced upper stage (AUS) or payload in a safe orbit and in a cost effective and reliable manner. The RLV is a horizontal takeoff and horizontal landing (HTHL), two-stage-to-orbit (TSTO) vehicle. The results of the study shows that an HTHL is cost effective because it implements airplane-like operation, infrastructure, and flight operations. The first stage of the TSTO is powered by Rocket-Based-Combined-Cycle (RBCC) engines, the second stage is powered by a LOX/LH rocket engine. The TSTO is used since it most effectively utilizes the capability of the RBCC engine. The analysis uses the NASA code POST (Program to Optimize Simulated Trajectories) to determine trajectories and weight in high-earth orbit for AUS/advanced payloads. Cost and reliability of an RLV versus current generation expandable launch vehicles are presented.

  13. Realistic Facial Expression of Virtual Human Based on Color, Sweat, and Tears Effects

    PubMed Central

    Alkawaz, Mohammed Hazim; Basori, Ahmad Hoirul; Mohamad, Dzulkifli; Mohamed, Farhan

    2014-01-01

    Generating extreme appearances such as scared awaiting sweating while happy fit for tears (cry) and blushing (anger and happiness) is the key issue in achieving the high quality facial animation. The effects of sweat, tears, and colors are integrated into a single animation model to create realistic facial expressions of 3D avatar. The physical properties of muscles, emotions, or the fluid properties with sweating and tears initiators are incorporated. The action units (AUs) of facial action coding system are merged with autonomous AUs to create expressions including sadness, anger with blushing, happiness with blushing, and fear. Fluid effects such as sweat and tears are simulated using the particle system and smoothed-particle hydrodynamics (SPH) methods which are combined with facial animation technique to produce complex facial expressions. The effects of oxygenation of the facial skin color appearance are measured using the pulse oximeter system and the 3D skin analyzer. The result shows that virtual human facial expression is enhanced by mimicking actual sweating and tears simulations for all extreme expressions. The proposed method has contribution towards the development of facial animation industry and game as well as computer graphics. PMID:25136663

  14. The origin of the transition voltage of gold-alkanedithiol-gold molecular junctions

    NASA Astrophysics Data System (ADS)

    Xiang, An; Wang, Minglang; Wang, Hao; Sun, Hantao; Hou, Shimin; Liao, Jianhui

    2016-02-01

    We studied the origin of the transition voltage of octanedithiol (C8DT) molecules sandwiched between two gold electrodes. Au-C8DT-Au molecular junctions were fabricated using the feedback controlled electromigration technique. The conductance measurement and the inelastic electron tunneling spectrum validate that the observed current-voltage characteristics indeed originate from the C8DT molecule in the junction. The transition voltage of Au-C8DT-Au junctions is determined to be about 0.95 V, which cannot be interpreted using the energy difference between the highest occupied molecular orbital or lowest unoccupied molecular orbital of the alkyl chain and the Fermi level of electrodes. Instead, we relate the measured transition voltage to the Au-S bonds, which are about 1.4 eV below the gold Fermi level. Our interpretation is supported by the ultraviolet photoelectron spectroscopy measurements and first-principles quantum transport simulations. These findings provide convincing evidence that the Au-S occupied states play a significant role in the charge transport of Au-alkanedithiol-Au molecular devices.

  15. A Method to Quantify and Compare Clinicians’ Assessments of Patient Understanding during Counseling of Standardized Patients

    PubMed Central

    Farrell, Michael H.; Kuruvilla, Pramita; Eskra, Kerry L.; Christopher, Stephanie A.; Brienza, Rebecca S.

    2009-01-01

    OBJECTIVES to introduce a method for quantifying clinicians’ use of assessment of understanding (AU) questions, and to examine medicine residents’ AU usage during counseling of standardized patients about prostate or breast cancer screening. METHODS Explicit-criteria abstraction was done on 86 transcripts, using a data dictionary for 4 AU types. We also developed a procedure for estimating the “load” of informational content for which the clinician has not yet assessed understanding. RESULTS Duplicate abstraction revealed reliability κ=0.96. Definite criteria for at least one AU were found in 68/86 transcripts (79%). Of these, 2 transcripts contained a request for a teach-back (“what is your understanding of this?”), 2 contained an open-ended AU, 46 (54%) contained only a close-ended AU, and 18 (21%) only contained an “OK?” question. The load calculation identified long stretches of conversation without an AU. CONCLUSION Many residents’ transcripts lacked AUs, and included AUs were often ineffectively phrased or inefficiently timed. Many patients may not understand clinicians, and many clinicians may be unaware of patients’ confusion. PRACTICE IMPLICATIONS Effective AU usage is important enough to be encouraged by training programs and targeted by population-scale quality improvement programs. This quantitative method should be useful in population-scale measurement of AU usage. PMID:19380210

  16. Realistic facial expression of virtual human based on color, sweat, and tears effects.

    PubMed

    Alkawaz, Mohammed Hazim; Basori, Ahmad Hoirul; Mohamad, Dzulkifli; Mohamed, Farhan

    2014-01-01

    Generating extreme appearances such as scared awaiting sweating while happy fit for tears (cry) and blushing (anger and happiness) is the key issue in achieving the high quality facial animation. The effects of sweat, tears, and colors are integrated into a single animation model to create realistic facial expressions of 3D avatar. The physical properties of muscles, emotions, or the fluid properties with sweating and tears initiators are incorporated. The action units (AUs) of facial action coding system are merged with autonomous AUs to create expressions including sadness, anger with blushing, happiness with blushing, and fear. Fluid effects such as sweat and tears are simulated using the particle system and smoothed-particle hydrodynamics (SPH) methods which are combined with facial animation technique to produce complex facial expressions. The effects of oxygenation of the facial skin color appearance are measured using the pulse oximeter system and the 3D skin analyzer. The result shows that virtual human facial expression is enhanced by mimicking actual sweating and tears simulations for all extreme expressions. The proposed method has contribution towards the development of facial animation industry and game as well as computer graphics. PMID:25136663

  17. The Relationship Between Soil Air Filled Porosity and Soil Methane Oxidation is Almost Identical in Both Dry and Wet Temperate Eucalypt Forests

    NASA Astrophysics Data System (ADS)

    Fest, B. J.; Wardlaw, T.; Hinko-Najera, N.; Arndt, S. K.

    2015-12-01

    In order to gain a better understanding of the temporal variation in soil methane (CH4) exchange in temperate evergreen eucalypt forests in south-eastern Australia we measured soil CH4 exchange in high temporal resolution (every 2 hours or less) over two consecutive years (Wombat State Forest, Victoria, AUS) and over one year (Warra, Tasmania, AUS) in two temperate Eucalyptus obliqua (L. Her) forests with contrasting annual precipitation (Wombat State Forest = 870 mm yr-1, Warra = 1700 mm yr-1). Both forests were continuous CH4 sinks with the Victorian site having a sink strength of -1.79 kg CH4 ha-1 yr-1 and the Tasmanian site having a sink strength of -3.83 kg CH4 ha-1 yr-1. Our results show that CH4 uptake was strongly controlled by soil moisture at both sites and explained up to 90% of the temporal variability in CH4 uptake. Furthermore, when soil moisture was expressed as soil air filled porosity (AFP) we were able to predict the CH4 uptake of one site by the linear regression between AFP and CH4 uptake from the other site. Soil temperature only had an apparent control over seasonal variation in CH4 uptake during periods when soil moisture and soil temperature were closely correlated. The fluctuation of the generally low soil nitrogen levels did not influence soil CH4 uptake at either site.

  18. The Structure of Dithiol Monolayers on Au(111).

    NASA Astrophysics Data System (ADS)

    Gallagher, M. C.; Macdairmid, A. R.; Banks, J. T.

    2003-03-01

    Using scanning tunneling microscopy (STM), Auger electron spectroscopy (AES), and contact angle measurements, we have studied the properties of Dithiothreitol (DTT) and Dithioerythritol (DTE) monolayers adsorbed on Au(111). DTT and DTE are both O-H functionalized α - ω dithiols. DTT is a chiral form whereas DTE is achiral. For comparison we have also studied the structure of octanethiol (n-alkanethiol, n = 8) SAMs. Octanethiol forms the characteristic close packed 3x3 monolayer with c(4x2) superstructure. In contrast, STM measurements of DTT films indicate much of the layer is disordered, however regions with local c(23x3) symmetry are observed. AES indicates the sulphur coverage for both DTT and octanethiol films are similar. AES studies involving Ellman's reagent, a marker species, also suggest a significant fraction of the DTT molecules in the adlayer bind to the gold via two Au-S bonds. Based on these results, we propose a structural model in which the majority of DTT molecules bind to the gold surface via two Au-S bonds and the distance between these two bonds is 3 times the underlying Au lattice spacing. Any differences between DTT and DTE layers due to differences in molecular structure will also be discussed.

  19. Suchmaschinen und Informationsqualität: Status quo, Problemfelder, Entwicklungstendenzen

    NASA Astrophysics Data System (ADS)

    Maaß, Christian; Gräfe, Gernot

    Das Thema Informationsqualität wird in den vorangegangenen Beiträgen umfangreich betrachtet. Die dabei geführte Diskussion zielt vordergründig auf organisatorische Dimensionen der Datenqualität, die strukturierte Datenanalyse oder Datenmanagementprozesse im Unternehmen ab. Dabei liegt ein Gro?teil der zur Unterstützung von Entscheidungsprozessen herangezogenen Informationen in Datenbanksystemen bzw. in einem Data Warehouse vor. Auf Basis verschiedener Analysetools (z. B. Online-Analytical-Processing) lassen sich diese Informationen dann systematisch auswerten. Allerdings können Entscheidungen nicht allein aufgrund der unternehmensintern vorliegenden Informationen getroffen werden. Vielmehr gilt es auch die aus der Unternehmensumwelt relevanten Informationen zu verarbeiten, die zum Teil über das Internet zugänglich sind. Im Gegensatz zu unternehmensinternen Datenbanksystemen handelt es sich beim Internet um ein schwach strukturiertes und offenes Netzwerk, weshalb die im Unternehmenskontext eingesetzten Analysetools kaum weiterhelfen, um Informationen mit hoher Qualität herauszufiltern. In dieser Situation spielen Suchmaschinen eine wichtige Rolle, um Informationen zu identifizieren und anhand verschiedener Kriterien in Form einer Suchergebnisseite zu sortieren. Konservative Schätzungen gehen davon aus, dass über Suchmaschinen zwischen 70 und 85 Prozent aller Informationsrecherchen im Internet erfolgen [Förster & Kreuz 2002, S. 68]. Teilweise beziffert man diesen Wert sogar auf über 90 Prozent [Schulz et al. 2005, S. 20]. Ungeachtet dieser herausragenden Stellung von Suchmaschinen kann konstatiert werden, dass die Qualität der Suchergebnisse oftmals nur gering ist.

  20. The role of fine-needle aspiration in the thyroid nodules of elderly patients

    PubMed Central

    Martini, Maurizio; Straccia, Patrizia; Lombardi, Celestino Pio; Pontecorvi, Alfredo; Larocca, Luigi Maria; Fadda, Guido

    2016-01-01

    We assess the role of thyroid fine needle aspiration cytology(FNAC) in our series of elderly patients. The growing subset of people aged older than 70 years has shown an increased incidence of thyroid diseases which need to be studied in order to reduce the percentage of surgical treatments in patients with higher likelihood of co-morbidities and associated life risk. We compared Follicular/Indeterminate Neoplasms(FN) and suspicious of malignancy(SM) with pediatric and adult cohorts. We discussed the role of immunocytochemistry-ICC to refine diagnoses. Four hundred and eighty out of 3539FNACs(13.5%) in elderly patients, were surgical followed-up. They included: 35Inadequate, 188benign(BL), 164FN/AUS, 49SM and 44positive for malignancy (PM). All PM and 95.7%BL were histological confirmed. The malignant rate was 24.3% mostly diagnosed as papillary thyroid carcinomas. An ICC panel (HBME-1 and Galectin-3) was carried out on liquid based cytology (LBC) and performed on FN/AUS, SM and PM. We found concordant positive ICC in 69.3%malignancies and concordant negative ICC in 97.6%benign follicular adenomas. Among FNs, 42.9%malignant histologic cases had concordant positivity whilst 97.4%benign histology had negative panel. Thyroid FNAC shows high feasibility in elderly patients. ICC helps in reducing the number of useless thyroidectomies and providing a more adequate clinical and/or surgical selection in elderly patients. PMID:26919251

  1. Yield Loss Caused by Pratylenchus thornei on Wheat in South Australia

    PubMed Central

    Nicol, Julie M.; Davies, Kerrie A.; Hancock, Trevor W.; Fisher, John M.

    1999-01-01

    A two-year field trial with 130 plots was conducted at Tanunda, South Australia. Ten cereal cultivars differing in susceptibility to Pratylenchus thornei, two poor host crops (non-leguminous), and a bare fallow treatment were used to manipulate the numbers of nematodes in the plots in the first year. Initial and final densities were determined for each plot and varied from 0 to 9,400 nematodes/200 g oven-dried soil at the beginning of the second year. A highly susceptible wheat cultivar, Warigal, and two wheat lines known to have some resistance to P. thornei, GS50A and AUS4930, were planted in the second year. High densities of P. thornei caused more extensive lesions and severe cortical degradation in roots of Warigal than in GS50A or AUS4930. There was a significant linear relationship between initial density of P. thornei and Warigal grain yield (t/ha), with the estimated regression equation Y = 1.86 - 0.0000557x, where Y is the grain yield in t/ha and x is the number of P. thornei/200 g oven-dried soil. High initial densities (9,000 P. thornei/200 g oven-dried soil) caused up to 27% yield loss of this commercial Australian wheat. In contrast, the yield of the two resistant lines was not affected by initial density, suggesting that both were tolerant as well as resistant in the field. PMID:19270909

  2. How reliable is the ReaxFF Potential for Describing the Structure of Alkanethiols on Gold? A Molecular Dynamics Study

    NASA Astrophysics Data System (ADS)

    Vasumathi, V.; Cordeiro, Maria Natalia D. S.

    2014-03-01

    The structures of self-assembled monolayers (SAMs) of short (methyl) and long (hexyl) chain alkyl thiols on the clean gold (111) surface were modelled using for the Au-S interactions either the reactive ReaxFF potential or the well known non-reactive Morse potential, while for the Au-Au interactions either the ReaxFF potential or an embedded-atom method (EAM). Analysis of the MD trajectories of possible SAM structures suggests that disordering of interfacial Au atoms is definitely driven by the gold-sulphur interactions. Our MD results reveal a novel structure where two methanethiol molecules are bound to a gold adatom that has been lifted from the surface at 300 K, and the same kind of RS-Au-SR motif was also observed for hexanethiol at 600 K but not at 300 K. What is more, the above motif is only observed for the reactive ReaxFF potential. Moreover, these results are in clear agreement with recent experiments and more costly first principles-based MD simulations. These findings strongly support the use of reactive potentials such as ReaxFF for gathering an accurate description of Au-S interactions in inexpensive classical MD simulations.

  3. Physiographic and land cover attributes of the Puget Lowland and the active streamflow gaging network, Puget Sound Basin

    USGS Publications Warehouse

    Konrad, Christopher; Sevier, Maria

    2014-01-01

    Geospatial information for the active streamflow gaging network in the Puget Sound Basin was compiled to support regional monitoring of stormwater effects to small streams. The compilation includes drainage area boundaries and physiographic and land use attributes that affect hydrologic processes. Three types of boundaries were used to tabulate attributes: Puget Sound Watershed Characterization analysis units (AU); the drainage area of active streamflow gages; and the catchments of Regional Stream Monitoring Program (RSMP) sites. The active streamflow gaging network generally includes sites that represent the ranges of attributes for lowland AUs, although there are few sites with low elevations (less than 60 meters), low precipitation (less than 1 meter year), or high stream density (greater than 5 kilometers per square kilometers). The active streamflow gaging network can serve to provide streamflow information in some AUs and RSMP sites, particularly where the streamflow gage measures streamflow generated from a part of the AU or that drains to the RSMP site, and that part of the AU or RSMP site is a significant fraction of the drainage area of the streamgage. The maximum fraction of each AU or RSMP catchment upstream of a streamflow gage and the maximum fraction of any one gaged basin in an AU or RSMP along with corresponding codes are provided in the attribute tables.

  4. Two separate gene clusters encode the biosynthetic pathway for the meroterpenoids, austinol and dehydroaustinol in Aspergillus nidulans

    PubMed Central

    Lo, Hsien-Chun; Entwistle, Ruth; Guo, Chun-Jun; Ahuja, Manmeet; Szewczyk, Edyta; Hung, Jui-Hsiang; Chiang, Yi-Ming; Oakley, Berl R.; Wang, Clay C. C.

    2012-01-01

    Meroterpenoids are a class of fungal natural products that are produced from polyketide and terpenoid precursors. An understanding of meroterpenoid biosynthesis at the genetic level should facilitate engineering of second-generation molecules and increasing production of first-generation compounds. The filamentous fungus Aspergillus nidulans has previously been found to produce two meroterpenoids, austinol and dehydroaustinol. Using targeted deletions that we created, we have determined that, surprisingly, two separate gene clusters are required for meroterpenoid biosynthesis. One is a cluster of four genes including a polyketide synthase gene, ausA. The second is a cluster of ten additional genes including a prenyltransferase gene, ausN, located on a separate chromosome. Chemical analysis of mutant extracts enabled us to isolate 3,5-dimethylorsellinic acid and ten additional meroterpenoids that are either intermediates or shunt products from the biosynthetic pathway. Six of them were identified as novel meroterpenoids in this study. Our data, in aggregate, allow us to propose a complete biosynthetic pathway for the A. nidulans meroterpenoids. PMID:22329759

  5. A system for telephone and secure email consultations, with automatic billing.

    PubMed

    Rutland, Jonathan; Marie, Catherine; Rutland, Benjamin

    2004-01-01

    Doctors have traditionally provided medical advice during face-to-face consultations. A new remote consultation service has been developed based on an interactive voice response system and Internet-based technologies. If the doctor is unavailable, a return call can be requested at a mutually convenient time. The patient's credit card is billed automatically. All that is required of the doctor and patient is access to any telephone. A dial-in dictation and transcription facility allows documentation. The service was launched in late 2003. After six months, there were approximately 55 doctors registered in five Australian states and approximately 500 patients registered. Two hundred and fifty consultations were selected randomly for analysis. Of these, 84% were conducted by telephone and 16% by email. The mean fees charged were AUS$17.11 for telephone and AUS$12.93 for email consultations. The mean duration of telephone consultations was 4.3 min. Call duration ranged from a few seconds to 20.5 min. PMID:15603623

  6. Wie verstehen Schülerinnen und Schüler den Begriff der Unendlichkeit?

    NASA Astrophysics Data System (ADS)

    Schimmöller, Tabea

    Wie Hilbert bereits feststellte, wirkt die Idee der Unendlichkeit, wie keine andere, schon seit Zeiten sehr anregend und fruchtbar auf den Verstand und bewegt das Gemüt der Menschen. Der Begriff der Unendlichkeit bedarf aber auch, wie kein anderer, der Aufklärung, denn mit ihm eröffnet sich ein weites Feld, welches nicht nur aus vielen verschiedenen Definitionen besteht, sondern auch aus völlig unterschiedlichen Disziplinen. Physiker suchen immer dringender nach einer "Theorie für Alles" oder einer "Weltformel", Kosmologen beschäftigen sich unter anderem mit der Ewigkeit des Universums, Theologen interessiert eher die Unendlichkeit Gottes, Philosophen diskutieren unter anderem Grenzfragen zwischen Naturwissenschaft und Philosophie und die Mathematiker versuchen den Paradoxien des Unendlichen einen Sinn zu geben. Und so wird ersichtlich, dass nichts abstrakter ist als das Unendliche: Obwohl die Unendlichkeit für die unterschiedlichsten Wissenschaften von großer Bedeutung ist, "[ist] in der Wirklichkeit das Unendliche nirgends zu finden, [egal] was für Erfahrungen und Beobachtungen und welcherlei Wissenschaft wir auch heranziehen".

  7. Sternbilder und ihre Mythen

    NASA Astrophysics Data System (ADS)

    Fasching, Gerhard

    Die Sternbilder, die seit alters her die Menschen in ihren Bann gezogen haben, und die damit verbundenen Mythen werden in zweifacher Weise vorgestellt. Erstens ist es die Absicht, dem Leser zu helfen, sich am Sternenhimmel zurechtzufinden, und zweitens will es ihm die Vielfalt der Bilder vermitteln, die damit verbunden sind. Am Anfang des Buches stehen die prächtigen Erzählungen aus Ovids Metamorphosen. Dann ist vom Sternenhimmel im Jahreskreis die Rede, um den Leser anzuregen, diesen fast unendlichen Bilderreichtum sich selbst durch eigene Beobachtungen zu erschließen. Ein umfangreicher Abschnitt behandelt die einzelnen Sternbilder und das hierzu überlieferte Wissen. Sternkarten und alte Kupferstiche aus dem Bestand der Österreichischen Nationalbibliothek zeigen, wie man sich in früheren Jahrhunderten den Sternenhimmel vorgestellt hat. Sternsagen und Mythen werden erzählt und auch das ptolemäische und das kopernikanische Weltsystem werden einander gegenübergestellt. Ausführliche Sachverzeichnisse mit über 3000 Suchbegriffen erleichtern den Zugang zu Stern- und Sternbildnamen und zur Mythologie.

  8. Datenintegration und Deduplizierung

    NASA Astrophysics Data System (ADS)

    Bleiholder, Jens; Schmid, Joachim

    In Unternehmen liegen viele Daten heutzutage immer seltener vollständig an einem einzigen physikalischen Ort vor, sondern sind weltweit verteilt. Dies liegt zum einen an der immer besser gewordenen Infrastruktur, die eine solche Verteilung auf einfache Art und Weise ermöglicht, und zum anderen an der Tatsache, dass viele Unternehmen weltweit tätig sind. So fallen Daten weltweit an, werden aber jeweils lokal - vor Ort - gespeichert. Daher müssen oft mehrere Datenquellen genutzt werden, um einen aktuellen, vollständigen und genauen Überblick über die vorhandenen Daten zu gewinnen. Datenintegration hilft, indem sie Daten aus mehreren Quellen zusammenführt und einheitlich darstellt. Diese integrierten Daten können genutzt werden, um sich einen Überblick über das Unternehmen zu verschaffen, z.B. wenn Unternehmen fusionieren und nur noch eine Kundendatenbank bestehen bleiben soll, oder wenn zu einem Kunden die Daten aus den verschiedenen Fachabteilungen zusammengeführt werden sollen. Anhand eines solchen Beispiels, der Integration von Kundendaten zu Kfz- und Lebensversicherungen erläutern wir im Folgenden einzelne Techniken.

  9. Herstellung eines federelastischen Spangutes geringer Dichte als Matrix für Schüttdämmstoffe, für plattenförmige Dämmstoffe und leichte Spanplatten

    NASA Astrophysics Data System (ADS)

    Tröger, Johannes; Groß, Lucia

    Klimaschutz und die ständig steigenden Energiekosten erfordern eine kontinuierliche Verbesserung der Dämmstoffe. Eine Alternative zur relativ kostenaufwändigen Wärmedämmung durch Platten bzw. Matten auf Basis von mineralischen Stoffen, ist der Einsatz von schütt-bzw. einblasbaren Dämmstoffpartikeln. Späne aus Holz und andere Dämmstoffe aus nachwachsenden Rohstoffen waren schon vor dem ersten Weltkrieg die gebräuchlichsten Dämmstoffe überhaupt. Seit etwa fünfzehn Jahren werden u.a. für den Holzhausbau im zunehmenden Maße auch Fräs-, Säge und Hobelspäne für Wärmedämmzwecke eingesetzt [1], [2], [3]. Hervorzuheben ist der ökologische Aspekt dieser Dämmstoffe durch die Bindung von CO2 und den sinkenden Heizenergiebedarf. Die bisherige Philosophie bei der Gewinnung von Dämmstoffspänen beruhte darauf, anfallendes Spangut stofflich weiter zu nutzen. Die Recyclingspäne sollten dabei sowohl die Setzungssicherheit als auch eine möglichst gute Wärmedämmung gewährleisten.

  10. Influence of the S-Au Bond Strength on the Magnetic Behavior of S-Capped Au Nanoparticles

    NASA Astrophysics Data System (ADS)

    Vázquez, María J. Rodríguez; Rivas, José; López-Quintela, M. Arturo; Mosquera, Antonio Mouriño; Torneiro, Mercedes

    Recently, large permanent atomic magnetic moments have been found in Au nanoparticles capped with thiols. It is assumed that the formation of localized Au-S bonds at the particle surface induces the damping of the surface plasmon resonance and the appearance of a ferromagnetic-like behavior. In this work we will show for the first time that thioethers can also induce both phenomena, i.e., the damping of the plasmon band and the appearance of permanent magnetic moments. Furthermore, we have studied the influence of the Au-S bond strength on both phenomena using two different synthesized thioether ligands. It will be shown that, although both ligands can induce a complete damping of the plasmon band, only with one of the ligands (the one corresponding to the stronger S-Au bond) the appearance of a ferromagnetic-like order is observed. This is an indication of the extreme sensitivity of the magnetism on the strength of the charge transfer at the S-Au bond.

  11. Linker Dependent Bond Rupture Force Measurements in Single-Molecule Junctions

    SciTech Connect

    Frei M.; Hybertsen M.; Aradhya S.V.; Venkataraman L.

    2012-02-16

    We use a modified conducting atomic force microscope to simultaneously probe the conductance of a single-molecule junction and the force required to rupture the junction formed by alkanes terminated with four different chemical link groups which vary in binding strength and mechanism to the gold electrodes. Molecular junctions with amine, methylsulfide, and diphenylphosphine terminated molecules show clear conductance signatures and rupture at a force that is significantly smaller than the measured 1.4 nN force required to rupture the single-atomic gold contact. In contrast, measurements with a thiol terminated alkane which can bind covalently to the gold electrode show conductance and force features unlike those of the other molecules studied. Specifically, the strong Au-S bond can cause structural rearrangements in the electrodes, which are accompanied by substantial conductance changes. Despite the strong Au-S bond and the evidence for disruption of the Au structure, the experiments show that on average these junctions also rupture at a smaller force than that measured for pristine single-atom gold contacts.

  12. Genomic sequences of Australian bluetongue virus prototype serotypes reveal global relationships and possible routes of entry into Australia.

    PubMed

    Boyle, David B; Bulach, Dieter M; Amos-Ritchie, Rachel; Adams, Mathew M; Walker, Peter J; Weir, Richard

    2012-06-01

    Bluetongue virus (BTV) is transmitted by biting midges (Culicoides spp.). It causes disease mainly in sheep and occasionally in cattle and other species. BTV has spread into northern Europe, causing disease in sheep and cattle. The introduction of new serotypes, changes in vector species, and climate change have contributed to these changes. Ten BTV serotypes have been isolated in Australia without apparent associated disease. Simplified methods for preferential isolation of double-stranded RNA (dsRNA) and template preparation enabled high-throughput sequencing of the 10 genome segments of all Australian BTV prototype serotypes. Phylogenetic analysis reinforced the Western and Eastern topotypes previously characterized but revealed unique features of several Australian BTVs. Many of the Australian BTV genome segments (Seg-) were closely related, clustering together within the Eastern topotypes. A novel Australian topotype for Seg-5 (NS1) was identified, with taxa spread across several serotypes and over time. Seg-1, -2, -3, -4, -6, -7, -9, and -10 of BTV_2_AUS_2008 were most closely related to the cognate segments of viruses from Taiwan and Asia and not other Australian viruses, supporting the conclusion that BTV_2 entered Australia recently. The Australian BTV_15_AUS_1982 prototype was revealed to be unusual among the Australian BTV isolates, with Seg-3 and -8 distantly related to other BTV sequences from all serotypes. PMID:22514341

  13. Gold nanoparticles with different capping systems: an electronic and structural XAS analysis.

    PubMed

    López-Cartes, C; Rojas, T C; Litrán, R; Martínez-Martínez, D; de la Fuente, J M; Penadés, S; Fernández, A

    2005-05-12

    Gold nanoparticles (NPs) have been prepared with three different capping systems: a tetralkylammonium salt, an alkanethiol, and a thiol-derivatized neoglycoconjugate. Also gold NPs supported on a porous TiO(2) substrate have been investigated. X-ray absorption spectroscopy (XAS) has been used to determine the electronic behavior of the different capped/supported systems regarding the electron/hole density of d states. Surface and size effects, as well as the role of the microstructure, have been also studied through an exhaustive analysis of the EXAFS (extended X-ray absorption fine structure) data. Very small gold NPs functionalized with thiol-derivatized molecules show an increase in d-hole density at the gold site due to Au-S charge transfer. This effect is overcoming size effects (which lead to a slightly increase of the d-electron density) for high S:Au atomic ratios and core-shell microstructures where an atomically abrupt Au-S interface likely does not exist. It has been also shown that thiol functionalization of very small gold NPs is introducing a strong distortion as compared to fcc order. To the contrary, electron transfer from reduced support oxides to gold NPs can produce a higher increase in d-electron density at the gold site, as compared to naked gold clusters. PMID:16852039

  14. Echtzeit-Ultraschallsimulation auf Grafik-Prozessoren mit CUDA

    NASA Astrophysics Data System (ADS)

    Reichl, Tobias; Passenger, Josh; Acosta, Oscar; Salvado, Olivier

    Trotz der zunehmenden Verbreitung jüngerer bildgebender Verfahren bleibt medizinischer Ultraschall (US) weiterhin ein wichtiges Hilfsmittel bei chirurgischen Eingriffen und der klinischen Diagnose. Viele US-gestützte medizinische Prozeduren erfordern allerdings ausgiebiges Training, so dass es wünschenswert ist, eine realistische Simulation von US-Bildern zur Verfügung zu stellen. Im Gegensatz zu früheren Ansätzen simulieren wir solche Bilder auf der "Graphics Processing Unit“. Wir erweitern hierzu eine Methode, die von Wein et al. für die Abschätzung von US-Reflexionen aus Daten der Computertomographie (CT) vorgeschlagen wurde, zu einer leichter zu berechnenden Form. Zusätzlich schätzen wir die US-Absorption aus den CT-Daten ab. Mit Hilfe von NVIDIAs "Compute Unified Device Architecture“ (CUDA) simulieren wir Reflexion, Verschattung, Rauschen und radiale Unschärfe, ausgehend von unbearbeiteten CT-Daten in Echtzeit und ohne Vorausberechnung.

  15. Nonverbal Social Withdrawal in Depression: Evidence from manual and automatic analysis

    PubMed Central

    Girard, Jeffrey M.; Cohn, Jeffrey F.; Mahoor, Mohammad H.; Mavadati, S. Mohammad; Hammal, Zakia; Rosenwald, Dean P.

    2014-01-01

    The relationship between nonverbal behavior and severity of depression was investigated by following depressed participants over the course of treatment and video recording a series of clinical interviews. Facial expressions and head pose were analyzed from video using manual and automatic systems. Both systems were highly consistent for FACS action units (AUs) and showed similar effects for change over time in depression severity. When symptom severity was high, participants made fewer affiliative facial expressions (AUs 12 and 15) and more non-affiliative facial expressions (AU 14). Participants also exhibited diminished head motion (i.e., amplitude and velocity) when symptom severity was high. These results are consistent with the Social Withdrawal hypothesis: that depressed individuals use nonverbal behavior to maintain or increase interpersonal distance. As individuals recover, they send more signals indicating a willingness to affiliate. The finding that automatic facial expression analysis was both consistent with manual coding and revealed the same pattern of findings suggests that automatic facial expression analysis may be ready to relieve the burden of manual coding in behavioral and clinical science. PMID:25378765

  16. Using artificial neural network and satellite data to predict rice yield in Bangladesh

    NASA Astrophysics Data System (ADS)

    Akhand, Kawsar; Nizamuddin, Mohammad; Roytman, Leonid; Kogan, Felix; Goldberg, Mitch

    2015-09-01

    Rice production in Bangladesh is a crucial part of the national economy and providing about 70 percent of an average citizen's total calorie intake. The demand for rice is constantly rising as the new populations are added in every year in Bangladesh. Due to the increase in population, the cultivation land decreases. In addition, Bangladesh is faced with production constraints such as drought, flooding, salinity, lack of irrigation facilities and lack of modern technology. To maintain self sufficiency in rice, Bangladesh will have to continue to expand rice production by increasing yield at a rate that is at least equal to the population growth until the demand of rice has stabilized. Accurate rice yield prediction is one of the most important challenges in managing supply and demand of rice as well as decision making processes. Artificial Neural Network (ANN) is used to construct a model to predict Aus rice yield in Bangladesh. Advanced Very High Resolution Radiometer (AVHRR)-based remote sensing satellite data vegetation health (VH) indices (Vegetation Condition Index (VCI) and Temperature Condition Index (TCI) are used as input variables and official statistics of Aus rice yield is used as target variable for ANN prediction model. The result obtained with ANN method is encouraging and the error of prediction is less than 10%. Therefore, prediction can play an important role in planning and storing of sufficient rice to face in any future uncertainty.

  17. Luminescent Gold Nanoparticles with Size-Independent Emission.

    PubMed

    Liu, Jinbin; Duchesne, Paul N; Yu, Mengxiao; Jiang, Xingya; Ning, Xuhui; Vinluan, Rodrigo D; Zhang, Peng; Zheng, Jie

    2016-07-25

    Size-independent emission has been widely observed for ultrasmall thiolated gold nanoparticles (AuNPs) but our understanding of the photoluminescence mechanisms of noble metals on the nanoscale has remained limited. Herein, we report how the emission wavelength of a AuNP and the local binding geometry of a thiolate ligand (glutathione) on the AuNP are correlated, as these AuNPs emit at different wavelengths in spite of their identical size (ca. 2.5 nm). By using circular dichroism, X-ray absorption, and fluorescence spectroscopy, we found that a high Au-S coordination number (CN) and a high surface coverage resulted in strong Au(I) -ligand charge transfer, a chiral conformation, and 600 nm emission, whereas a low Au-S CN and a low surface coverage led to weak charge transfer, an achiral conformation, and 810 nm emission. These two size-independent emissions can be integrated into one single 2.5 nm AuNP by fine-tuning of the surface coverage; a ratiometric pH response was then observed owing to strong energy transfer between two emission centers, opening up new possibilities for the design of ultrasmall ratiometric pH nanoindicators. PMID:27348584

  18. Edelgase als Tracer für Wechselwirkungen von Krusten- und Mantelfluiden mit diamantführenden Gesteinen des östlichen Baltischen Schildes

    NASA Astrophysics Data System (ADS)

    Wiersberg, Thomas

    2001-11-01

    In der vorliegenden Arbeit werden anhand der Edelgaszusammensetzung von Kimberliten und Lamproiten sowie ihrer gesteinsbildenden Minerale die Wechselwirkungen dieser Gesteine mit Fluiden diskutiert. Die untersuchten Proben stammen vom östlichen Baltischen Schild, vom Kola-Kraton (Poria Guba und Kandalaksha) und vom karelischen Kraton (Kostamuksha). Edelgasanalysen nach thermischer oder mechanischer Gasextraktion von 23 Gesamtgesteinsproben und 15 Mineralseparaten ergeben folgendes Bild: Helium- und Neon-Isotopendaten der Fluideinschlüsse von Lamproiten aus Kostamuksha lassen auf den Einfluss einer fluiden Phase krustaler Herkunft schliessen. Diese Wechselwirkungen fanden wahrscheinlich schon während des Magmenaufstiegs statt, denn spätere Einflüsse krustaler Fluide auf die Lamproite und ihr Nebengestein (Quarzit) sind gering, wie anhand der C/36Ar-Zusammensetzung gezeigt wird. Auch sind die mit verschiedenen Datierungsmethoden (Rb-Sr, Sm-Nd, K-Ar) an Mineralseparaten und teilweise an Gesamtgestein ermittelten Alter konsistent und machen eine metamorphe Überprägung unwahrscheinlich. Aufgrund der Verteilung der primordialen Edelgasisotope zwischen Fluideinschlüssen und Gesteinsmatrix ist ein langsamer Magmenaufstieg anzunehmen, was die Möglichkeit der Kontamination mit einem krustalen Fluid während des Magmenaufstiegs erhöht. Die Gasextraktion aus Mineralseparaten erfolgte thermisch, wodurch eine Freisetzung der Gase ausschließlich aus Fluideinschlüssen nicht möglich ist. Hierbei zeigen Amphibol und Klinopyroxen, separiert aus Kostamuksha-Lamproiten, in ihrer Neon-Isotopenzusammensetzung im Vergleich zur krustalen Zusammensetzung (Kennedy et al., 1990) ein leicht erhöhtes Verhältnis von 20Ne/22Ne, was ein Hinweis auf Mantel-Neon sein könnte. Kalifeldspäte, Quarz und Karbonate enthalten dagegen nur Neon krustaler Zusammensetzung. Phlogopite haben sehr kleine Verhältnisse von 20Ne/22Ne und 21Ne/22Ne, zurückzuführen auf in-situ-Produktion von 22Ne

  19. Microbial Life in an Underground Gas Storage Reservoir

    NASA Astrophysics Data System (ADS)

    Bombach, Petra; van Almsick, Tobias; Richnow, Hans H.; Zenner, Matthias; Krüger, Martin

    2015-04-01

    While underground gas storage is technically well established for decades, the presence and activity of microorganisms in underground gas reservoirs have still hardly been explored today. Microbial life in underground gas reservoirs is controlled by moderate to high temperatures, elevated pressures, the availability of essential inorganic nutrients, and the availability of appropriate chemical energy sources. Microbial activity may affect the geochemical conditions and the gas composition in an underground reservoir by selective removal of anorganic and organic components from the stored gas and the formation water as well as by generation of metabolic products. From an economic point of view, microbial activities can lead to a loss of stored gas accompanied by a pressure decline in the reservoir, damage of technical equipment by biocorrosion, clogging processes through precipitates and biomass accumulation, and reservoir souring due to a deterioration of the gas quality. We present here results from molecular and cultivation-based methods to characterize microbial communities inhabiting a porous rock gas storage reservoir located in Southern Germany. Four reservoir water samples were obtained from three different geological horizons characterized by an ambient reservoir temperature of about 45 °C and an ambient reservoir pressure of about 92 bar at the time of sampling. A complementary water sample was taken at a water production well completed in a respective horizon but located outside the gas storage reservoir. Microbial community analysis by Illumina Sequencing of bacterial and archaeal 16S rRNA genes indicated the presence of phylogenetically diverse microbial communities of high compositional heterogeneity. In three out of four samples originating from the reservoir, the majority of bacterial sequences affiliated with members of the genera Eubacterium, Acetobacterium and Sporobacterium within Clostridiales, known for their fermenting capabilities. In

  20. Atomic structure of a peptide coated gold nanocluster identified using theoretical and experimental studies

    NASA Astrophysics Data System (ADS)

    Wang, Hui; Li, Xu; Gao, Liang; Zhai, Jiao; Liu, Ru; Gao, Xueyun; Wang, Dongqi; Zhao, Lina

    2016-06-01

    Peptide coated gold nanoclusters (AuNCs) have a precise molecular formula and atomic structure, which are critical for their unique applications in targeting specific proteins either for protein analysis or drug design. To date, a study of the crystal structure of peptide coated AuNCs is absent primarily due to the difficulty of obtaining their crystalline phases in an experiment. Here we study a typical peptide coated AuNC (Au24Peptide8, Peptide = H2N-CCYKKKKQAGDV-COOH, Anal. Chem., 2015, 87, 2546) to figure out its atomic structure and electronic structure using a theoretical method for the first time. In this work, we identify the explicit configuration of the essential structure of Au24Peptide8, Au24(Cys-Cys)8, using density functional theory (DFT) computations and optical spectroscopic experiments, where Cys denotes cysteine without H bonded to S. As the first multidentate ligand binding AuNC, Au24(Cys-Cys)8 is characterized as a distorted Au13 core with Oh symmetry covered by two Au(Cys-Cys) and three Au3(Cys-Cys)2 staple motifs in its atomic structure. The most stable configuration of Au24(Cys-Cys)8 is confirmed by comparing its UV-vis absorption spectrum from time-dependent density-functional theory (TDDFT) calculations with optical absorption measurements, and these results are consistent with each other. Furthermore, we carry out frontier molecular orbital (FMO) calculations to elucidate that the electronic structure of Au24(Cys-Cys)8 is different from that of Au24(SR)20 as they have a different Au/S ratio, where SR represents alkylthiolate. Importantly, the different ligand coatings, Cys-Cys and SR, in Au24(Cys-Cys)8 and Au24(SR)20 cause the different Au/S ratios in the coated Au24. The reason is that the Au/S ratio is crucial in determining the size of the Au core of the ligand protected AuNC, and the size of the Au core corresponds to a specific electronic structure. By the adjustment of ligand coatings from alkylthiolate to peptide, the Au/S ratio

  1. Construction of sensitive and selective zirconia-based CO sensors using ZnCr2O(4)-based sensing electrodes.

    PubMed

    Fujio, Yuki; Plashnitsa, Vladimir V; Breedon, Michael; Miura, Norio

    2012-01-17

    The carbon monoxide (CO) sensitivity of a mixed-potential-type yttria-stabilized zirconia (YSZ)-based tubular-type sensor utilizing a ZnCr(2)O(4) sensing electrode (SE) was tuned by the addition of different precious metal nanoparticles (Ag, Au, Ir, Pd, Pt, Ru and Rh; 1 wt % each) into the sensing layer. After measuring the electromotive force (emf) response of the fabricated SEs to 100 ppm of CO against a Pt/air-reference electrode (RE), the ZnCr(2)O(4)-Au nanoparticle composite electrode (ZnCr(2)O(4)(+Au)-SE) was found to give the highest response to CO. A linear dependence on the logarithm of CO concentration in the range of 20-800 ppm at an operational temperature of 550 °C under humid conditions (5 vol % water vapor) was observed. From the characterization of the ZnCr(2)O(4)(+Au)-SE, we can conclude that the engineered high response toward CO originated from the specific properties of submicrometer sized Au particles, formed via the coalescence of nanosized Au particles located on ZnCr(2)O(4) grains, during the calcining process at 1100 °C for 2 h. These particles augmented the catalytic activities of the gas-phase CO oxidation reaction in the SE layer, as well as to the anodic reaction of CO at the interface; while suppressing the cathodic reaction of O(2) at the interface. In addition, the response of the ZnCr(2)O(4)(+Au)-SE sensor toward 100 ppm of CO gradually increased throughout the 10 days of operation, and plateaued for the remainder of the month that the sensor was examined. Correlations between SEM observations and the CO sensing characteristics of the present sensor were suggestive that the sensitivity was mostly affected by the morphology of the Au particles and their catalytic activities, which were in close proximity to the ZnCr(2)O(4) grains. Furthermore, by measuring the potential difference (emf) between the ZnCr(2)O(4)(+Au) and a ZnCr(2)O(4) electrode, sensitivities to typical exhaust component gases other than CO were found to be

  2. The effect of thiosulfate-oxidizing bacteria on the stability of the gold-thiosulfate complex

    NASA Astrophysics Data System (ADS)

    Lengke, Maggy F.; Southam, Gordon

    2005-08-01

    An Acidithiobacillus thiooxidans spp., isolated from the Driefontein Consolidated Gold Mine, Witwatersrand Basin, Republic of South Africa was able to precipitate gold from Au(S 2O 3) 23- in the presence of up to 0.26 mM gold. In chemical control experiments and with the presence of dead bacteria, gold was not precipitated under similar experimental conditions and duration. During growth, the pH of the culture medium decreased from pH 5.4 to 1.9, while the Eh increased from 0.3 to between 0.5 to 0.6 V within a period of 75 days. In the active (live) bacterial culture systems, acid production enhanced thiosulfate disproportionation, after which the elemental sulfur and any other intermediate sulfur species were oxidized completely to sulfate. The gold, Au(S 2O 3) 23-, was stable in the bacterial systems until sulfur oxidation was complete; then the bacteria precipitated gold from Au(S 2O 3) 23-. The bacterial systems (0.02-0.26 mM gold) precipitated 87 to 100% of the gold under diurnal light exposure, while only 11 to 69% of the gold was precipitated in the dark. The presence of gold (≥0.08 mM) reduced bacterial growth, disrupted cell division causing cell elongation, and was ultimately toxic to this bacterium, killing the cultures. The gold was precipitated inside the bacterial cells as fine-grained colloids ranging between 5 and 10 nm in diameter and in the bulk fluid phase as crystalline micrometer-scale gold. Observations using transmission electron microscopy revealed that the gold was deposited throughout the cell; however, it was concentrated in the cell envelope, especially along the cytoplasmic membrane, suggesting that gold precipitation was likely enhanced via electron transport processes associated with energy generation. Seven months after population growth had stopped, the gold had formed coiled or wire gold, irregular and rounded structures with an approximate size ranging from 0.5 to 5 μm, and crystalline octahedral gold.

  3. Molecular alligator clips: a theoretical study of adsorption of S, Se and S H on Au(111)

    NASA Astrophysics Data System (ADS)

    Mankefors, S.; Grigoriev, A.; Wendin, G.

    2003-08-01

    For the binding of thiols to Au, the Au-S interaction is decisive for the geometry, bonding strength and transmissivity of the metal-molecule interface. Using ab initio methods we investigate the adsorption of sulfur (S) on the Au(111) surface for different coverages between 0.25 and 1.0 monolayers (ML). Corresponding geometries with adsorbed Se are included to establish possible differences between S- and Se-based metal-molecule interfaces. We furthermore investigate hydrogenation of sulfur-covered Au(111) surfaces to establish the energetics and resulting geometry of adsorption of S-H groups on clean Au(111), using it as a simple model system. For the relatively low coverage of 0.25 ML the S and Se atoms are found to prefer the in-hollow sites, with Se displaying a substantially stronger bond. Increasing the coverage leads to depletion of available free charge in the gold surface, which weakens the bonds to the S (Se). Due to the more extensive hybridization, Se is more insensitive to the exact geometry, and the stacking fault position only costs 0.04 eV. At even higher coverage (0.75 ML) the adsorbed atoms hybridize internally and form triatomic molecules situated on top of the Au surface atoms. In S (Se) rich environments this turns out to be the most stable configuration investigated, while in S (Se) poor conditions the surface will adsorb all available S (Se). Forcing the system to adsorb atoms beyond this coverage increases the total energy. For all physically realizable coverages the Au-Se bond is found to be geq0.25 eV stronger than the corresponding Au-S bond. The Se bond also displays a higher degree of metallicity and should be expected to make a better head group for thiols, for example; this is relevant for both bonding and conductivity. Turning to the hydrogenated S systems we find that surfaces with a high coverage of S only weakly bind H at low partial hydrogenation, while H adsorption in systems with medium and low S concentrations is found to be

  4. Effects of bonding type and interface geometry on coherent transport through the single-molecule magnet Mn12

    NASA Astrophysics Data System (ADS)

    Park, Kyungwha; Barraza-Lopez, Salvador; García-Suárez, Víctor M.; Ferrer, Jaime

    2010-03-01

    We examine theoretically coherent electron transport through the single-molecule magnet Mn12 , bridged between Au(111) electrodes, using the nonequilibrium Green’s function method and the density-functional theory. We analyze the effects of bonding type, molecular orientation, and geometry relaxation on the electronic properties and charge and spin transport across the single-molecule junction. We consider nine interface geometries leading to five bonding mechanisms and two molecular orientations: (i) Au-C bonding, (ii) Au-Au bonding, (iii) Au-S bonding, (iv) Au-H bonding, and (v) physisorption via van der Waals forces. The two molecular orientations of Mn12 correspond to the magnetic easy axis of the molecule aligned perpendicular [hereafter denoted as orientation (1)] or parallel [orientation (2)] to the direction of electron transport. We find that the electron transport is carried by the lowest unoccupied molecular orbital (LUMO) level in all the cases that we have simulated. Relaxation of the junction geometries mainly shifts the relevant occupied molecular levels toward the Fermi energy as well as slightly reduces the broadening of the LUMO level. As a result, the current slightly decreases at low bias voltage. Our calculations also show that placing the molecule in the orientation (1) broadens the LUMO level much more than in the orientation (2) due to the internal structure of the Mn12 . Consequently, junctions with the former orientation yield a higher current than those with the latter. Among all of the bonding types considered, the Au-C bonding gives rise to the highest current (about one order of magnitude higher than the Au-S bonding), for a given distance between the electrodes. The current through the junction with other bonding types decreases in the order of Au-Au, Au-S, and Au-H. Importantly, the spin-filtering effect in all the nine geometries stays robust and their ratios of the majority-spin to the minority-spin transmission coefficients are

  5. Examination of commercially available copper oxide wire particles in combination with albendazole for control of gastrointestinal nematodes in lambs.

    PubMed

    Burke, J M; Miller, J E; Terrill, T H; Smyth, E; Acharya, M

    2016-01-15

    Control of gastrointestinal nematodes (GIN) remains a critical issue due to the prevalence of anthelmintic resistance. The objective of the experiment was to determine the efficacy of copper oxide wire particles (COWP) from three commercial sources and a combination of COWP and albendazole to control GIN and/or Haemonchus contortus in lambs. Naturally infected Katahdin lambs in early June 2014 and 2015 were randomly assigned to receive no COWP (CON; n=9 and 12) or 2g COWP in a gel capsule as Copasure(®) (COP; n=4 and 17; Animax Ltd.), copper oxide-wire form (AUS; n=7 in 2014 only; Pharmplex), Ultracruz™ (ULT; n=8 and 15; Santa Cruz Animal Health™), no COWP and albendazole (CON+alb; n=10 in 2015 only; 15mg/kg BW; Valbazen(®); Zoetis Animal Health), or COWP+alb (n=7 and 11; in 2014, lambs were administered alb on day 3). Lambs grazed grass pastures as a group and were supplemented with 227g/lamb daily of a commercial grain mix (15% crude protein) and the same amount of alfalfa pellets. Feces were collected on days 0 (day of COWP treatment), 7, and 14 for determination of fecal egg counts (FEC). Pooled (2014) or pooled treatment group feces were cultured on days 0, 7, and 14 (2015 only) to determine GIN genera. Data were analyzed using repeated measures in a mixed model, and FEC were log transformed. The predominant GIN on day 0 was H. contortus (87%) in 2014, and there was a mixed population in 2015. The mean FEC was reduced by day 7 in AUS and ULT lambs (treatment×day, P=0.001), and all of the COWP products were similar. By day 14, the AUS FEC were lower than the CON and COP groups. When examining the combination of COWP and synthetic anthelmintic, the FEC of COWP+alb were reduced to nearly 0eggs/g (back-transformed) and lower than the other groups (treatment×day, P=0.001). The percentage of H. contortus in cultured feces was reduced to a greater extent in the COWP than CON or CON+alb groups of lambs. In a mixed GIN population, the COWP products appeared to

  6. Mono- and bi-functional arenethiols as surfactants for gold nanoparticles: synthesis and characterization

    NASA Astrophysics Data System (ADS)

    Vitale, Floriana; Fratoddi, Ilaria; Battocchio, Chiara; Piscopiello, Emanuela; Tapfer, Leander; Russo, Maria Vittoria; Polzonetti, Giovanni; Giannini, Cinzia

    2011-12-01

    Stable gold nanoparticles stabilized by different mono and bi-functional arenethiols, namely, benzylthiol and 1,4-benzenedimethanethiol, have been prepared by using a modified Brust's two-phase synthesis. The size, shape, and crystalline structure of the gold nanoparticles have been determined by high-resolution electron microscopy and full-pattern X-ray powder diffraction analyses. Nanocrystals diameters have been tuned in the range 2 ÷ 9 nm by a proper variation of Au/S molar ratio. The chemical composition of gold nanoparticles and their interaction with thiols have been investigated by X-ray photoelectron spectroscopy. In particular, the formation of networks has been observed with interconnected gold nanoparticles containing 1,4-benzenedimethanethiol as ligand.

  7. Gebändigtes Knallgas: Brennstoffzellen im mobilen und stationären Einsatz

    NASA Astrophysics Data System (ADS)

    Waidhas, Manfred; Landes, Harald

    2001-07-01

    Die Brennstoffzelle hat aus technischer Sicht einen hohen Stand erreicht. Die PEMFC konnte ihre Zuverlässigkeit in einer Reihe von Nischenanwendungen, aber auch in Form erster mobiler und dezentraler Prototypen beweisen. Die SOFC und die MCFC konnten bereits in Anlagen von 100 kW und mehr in Erprobung gehen. Um jedoch wirtschaftlich konkur-renzfähig zu den etablierten Technologien der mobilen und dezentralen Energiewandlung zu werden, muss noch eine drastische Kostenreduktion sowohl beim Brennstoffzellen-Stack als auch bei den zu seinem Betrieb notwendigen Hilfsaggregaten erreicht werden. Für Fahrzeugantriebe muss außerdem eine Antwort auf die noch offene Treibstofffrage (Infrastruktur, H2-Erzeugung und H2-Speicherung) gefunden werden.

  8. Assessment of undiscovered conventional oil and gas resources, onshore Claiborne Group, United Statespart of the northern Gulf of Mexico Basin

    USGS Publications Warehouse

    Hackley, P.C.; Ewing, T.E.

    2010-01-01

    The middle Eocene Claiborne Group was assessed for undiscovered conventional hydrocarbon resources using established U.S. Geological Survey assessment methodology. This work was conducted as part of a 2007 assessment of Paleogene-Neogene strata of the northern Gulf of Mexico Basin, including the United States onshore and state waters (Dubiel et al., 2007). The assessed area is within the Upper Jurassic-CretaceousTertiary composite total petroleum system, which was defined for the assessment. Source rocks for Claiborne oil accumulations are interpreted to be organic-rich, downdip, shaley facies of the Wilcox Group and the Sparta Sand of the Claiborne Group; gas accumulations may have originated from multiple sources, including the Jurassic Smackover Formation and the Haynesville and Bossier shales, the Cretaceous Eagle Ford and Pearsall (?) formations, and the Paleogene Wilcox Group and Sparta Sand. Hydrocarbon generation in the basin started prior to deposition of Claiborne sediments and is currently ongoing. Primary reservoir sandstones in the Claiborne Group include, from oldest to youngest, the Queen City Sand, Cook Mountain Formation, Sparta Sand, Yegua Formation, and the laterally equivalent Cockfield Formation. A geologic model, supported by spatial analysis of petroleum geology data, including discovered reservoir depths, thicknesses, temperatures, porosities, permeabilities, and pressures, was used to divide the Claiborne Group into seven assessment units (AUs) with three distinctive structural and depositional settings. The three structural and depositional settings are (1) stable shelf, (2) expanded fault zone, and (3) slope and basin floor; the seven AUs are (1) lower Claiborne stable-shelf gas and oil, (2) lower Claiborne expanded fault-zone gas, (3) lower Claiborne slope and basin-floor gas, (4) lower Claiborne Cane River, (5) upper Claiborne stable-shelf gas and oil, (6) upper Claiborne expanded fault-zone gas, and (7) upper Claiborne slope and basin

  9. Sind die klassischen Methoden zur mykologischen Diagnostik noch "State-of-the-Art"?

    PubMed

    Wiegand, Cornelia; Bauer, Andrea; Brasch, Jochen; Nenoff, Pietro; Schaller, Martin; Mayser, Peter; Hipler, Uta-Christina; Elsner, Peter

    2016-05-01

    Die Labordiagnose einer Pilzinfektion der Haut basiert traditionell auf dem Nativpräparat und der Anzucht des Erregers aus dem klinischen Material. Auch der dermato- histologischer Nachweis von Pilzelementen ist möglich. Diese Methoden sind, sofern sie korrekt ausgeführt werden, in der Regel zum Pilznachweis geeignet. Im Zuge der personalisierten Medizin und den daraus erwachsenden Aufgaben werden jedoch neue Verfahren erforderlich, welche einfach, spezifisch und schnell sind. Der zusätzliche Einsatz von DNA-basierten molekularen Methoden erhöht die Empfindlichkeit sowie die diagnostische Spezifität und reduziert die zum Teil wochenlange Durchführungszeit der konventionellen mykologischen Diagnostik auf 24 bis 48 Stunden. Im Zuge der stetigen Weiterentwicklung im Bereich der personalisierten Medizin sind einfache Analysensysteme auf PCR-Basis denkbar, die in der Hautarztpraxis eine Dermatophyten-Sofort-Diagnostik erlauben (Point-of-Care-Tests). PMID:27119469

  10. Die Zeitung der Zukunft

    NASA Astrophysics Data System (ADS)

    Wieser, Christoph; Schaffert, Sebastian

    Schon lange wird spekuliert, wie wir in Zukunft Zeitung lesen werden. Werden wir am Frühstückstisch wie gewohnt in einer Zeitung aus Papier schmökern oder werden wir die Zeitung als biegsame Folie beschrieben mit elektronischer Tinte in Händen halten? Wird die Zeitung mit anderen Medien wie Radio und Fernsehen verschmelzen? Viele Varianten sind denkbar. Heute lässt sich schon ein Trend ablesen: Immer mehr Leser entdecken die Online-Zeitung als Informationsmedium, eine Voraussetzung für die Nutzung neuer Technologien in der Zeitung der Zukunft. In diesem Kapitel stellen wir Entwicklungsmöglichkeiten der Online-Zeitung dar, wie sie im Social Semantic Web möglich werden.

  11. The Formation and Binding of Gold Nanoparticles onto Wool Fibres

    SciTech Connect

    Johnston, James H.; Burridge, Kerstin A.; Kelly, Fern M.

    2009-07-23

    This paper presents the novel use of nanosize gold with different plasmon resonance colours, as stable colourfast colourants on wool fibres for use in high quality fabrics and textiles. The gold nanoparticles are synthesised by the controlled reduction of Au{sup 3+} in the AuCl{sub 4}{sup -} complex to Au{sup 0} onto the surface of the wool where they attach to the S in the cystine amino acids in wool keratin proteins. Scanning electronmicroscopy shows the nanoparticles are present on the cuticles of the fibre surface and are concentrated at the edges of these cuticles. EDS analysis shows a strong correlation of Au with S and X-ray photoelectron spectroscopy suggests Au-S bond formation. Hence the nanogold colourants are chemically bound to the wool fibre surface and do not fade as traditional organic dyes do. A range of coloured fibres have been produced.

  12. SPICES: Spectro-Polarimetric Imaging and Characterization of Exoplanetary Systems - From Planetary Disks To Nearby Super Earths

    NASA Technical Reports Server (NTRS)

    Boccaletti, Anthony; Schneider, Jean; Traub, Wes; Lagage, Pierre-Olivier; Stam, Daphne; Gratton, Raffaele; Trauger, John; Cahoy, Kerri; Snik, Frans; Baudoz, Pierre; Galicher, Raphael; Reess, Jean-Michel; Mawet, Demitri; Augereau, Jean-Charles; Patience, Jenny; Kuchner, Marc; Wyatt, Mark; Pantin, Eric; Maire, Anne-Lise; Verinaud, Christophe; Ronayette, Samuel; Dubreuil, Didier; Belikov, Russ; Marley, M.; Stapelfeldt, K.

    2012-01-01

    SPICES (Spectro-Polarimetric Imaging and Characterization of Exoplanetary Systems) is a five-year M-class mission proposed to ESA Cosmic Vision. Its purpose is to image and characterize long-period extrasolar planets and circumstellar disks in the visible (450-900 nm) at a spectral resolution of about 40 using both spectroscopy and polarimetry. By 2020/2022, present and near-term instruments will have found several tens of planets that SPICES will be able to observe and study in detail. Equipped with a 1.5 m telescope, SPICES can preferentially access exoplanets located at several AUs (0.5-10 AU) from nearby stars (less than 25 pc) with masses ranging from a few Jupiter masses to Super Earths (approximately 2 Earth radii, approximately 10 mass compared to Earth) as well as circumstellar disks as faint as a few times the zodiacal light in the Solar System.

  13. Berechnung verkehrlicher Substitutionseffekte im Personenverkehr bei Online-Shopping

    NASA Astrophysics Data System (ADS)

    Nerlich, Mark R.; Schiffner, Felix; Vogt, Walter; Rauh, Jürgen; Breidenbach, Petra

    Für Güter des täglichen, mittelfristigen und langfristigen Bedarfs sowie für das Beispiel Baumarktartikel wird das Potenzial für Personenverkehrsaufwand von Einkaufsaktivtäten quantitativ abgeschätzt. Die entwickelten Algorithmen behandeln die einkaufsvorbereitende Information und den eigentlichen Einkauf, d.h. den Erwerb eines Gutes, separat. Informationsaktivitäten haben insbesondere bei höherwertigen Gütern einen hohen Stellenwert und damit auch verkehrliche Relevanz. Wie Berechnungen zeigen, spart Online-Shopping Informations- und Einkaufsverkehrsaufwand im Pkw-Verkehr ein. Die notwendigen Eingangsdaten wie differenzierte Informations- und Einkaufshäufigkeiten sowie verkehrliche Parameter zu Verkehrsmittelwahl, Entfernungen und Wegekopplungen wurden aus eigenen Erhebungen gewonnen.

  14. Realistic facial animation generation based on facial expression mapping

    NASA Astrophysics Data System (ADS)

    Yu, Hui; Garrod, Oliver; Jack, Rachael; Schyns, Philippe

    2014-01-01

    Facial expressions reflect internal emotional states of a character or in response to social communications. Though much effort has been taken to generate realistic facial expressions, it still remains a challenging topic due to human being's sensitivity to subtle facial movements. In this paper, we present a method for facial animation generation, which reflects true facial muscle movements with high fidelity. An intermediate model space is introduced to transfer captured static AU peak frames based on FACS to the conformed target face. And then dynamic parameters derived using a psychophysics method is integrated to generate facial animation, which is assumed to represent natural correlation of multiple AUs. Finally, the animation sequence in the intermediate model space is mapped to the target face to produce final animation.

  15. Minimalinvasive endovaskuläre Stent-Therapie bei Erkrankungen in der thorakalen Aorta

    NASA Astrophysics Data System (ADS)

    Voss, Bernhard; Bauernschmitt, Robert; Brockmann, Gernot; Lange, Rüdiger

    Die Inzidenz der Aortenerkrankungen nimmt aufgrund der Überalterung der Bevölkerung stetig zu und hat sich innerhalb der letzten 20 Jahre von 2,9 auf 10,9 pro 100.000 Einwohner mehr als verdreifacht [1]. Bei Aortenerkrankungen muss zwischen Aneurysmen und Dissektionen unterschieden werden. Der Begriff Aneurysma (Abb. 62.1) bezeichnet die Ausweitung eines arteriellen Blutgefäßes. Sind dabei alle Wandschichten, also innere Schicht (Intima), mittlere Schicht (Media) und äußere Schicht (Adventitia) betroffen, so spricht man von einem echten Aneurysma (Aneurysma verum). Besteht die Aneurysmawand nur aus adventitiellem Gewebe, spricht man von einem falschen Aneurysma. Ursache für ein Aneurysma ist eine Schwächung der elastischen Kräfte der Media, die dann dem intravaskulären Druck nicht mehr standhalten kann.

  16. Der neue Kosmos. Einführung in die Astronomie und Astrophysik

    NASA Astrophysics Data System (ADS)

    Unsöld, Albrecht; Baschek, Bodo

    Der neue Kosmos bietet in überschaubarem Umfang eine zusammenhängende Einführung in das Gesamtgebiet der Astronomie und Astrophysik. Aus den Bereichen: Klassische Astronomie und Planetensystem, Instrumente und Beobachtungsverfahren, Sonne und Sterne, Milchstraße und Galaxien, Kosmologie, Entstehung des Planetensystems, Entwicklung der Erde und des Lebens werden die Beobachtungsmethoden und die Ergebnisse astronomischer Forschung sowie deren theoretische Grundlagen und wechselseitigen Zusammenhänge vermittelt. Die aktualisierte 7. Auflage berücksichtigt den raschen Fortschritt astronomischer Forschung der letzten drei Jahre von unserem Planetensystem und den Entdeckungen zahlreicher Planeten bei anderen Sternen, über die fernsten Galaxien und Quasare bis zur Entwicklung der modernen Kosmologie.

  17. Plasmakristalle an Bord der ISS: Komplexe Plasmen in Schwerelosigkeit

    NASA Astrophysics Data System (ADS)

    Thomas, Hubertus M.; Morfill, Gregor E.

    2005-03-01

    Das deutsch-russische Experiment PKE-Nefedov erforscht komplexe Plasmen in Schwerelosigkeit. Seit 2001 arbeitet es auf der internationalen Raumstation ISS. Komplexe Plasmen bestehen aus einem teilweise ionisierten Gas, das Mikropartikel enthält. Diese Partikel laden sich im Strom der Elektronen und Ionen elektrisch auf. Ihr Verhalten beeinflussen vor allem abgeschirmte Coulomb-Kräfte und Reibungskräfte im Gas. Sie können sich sogar zu einem Plasma-Kristall anordnen. Diese reguläre, dreidimensionale Struktur hat viele Eigenschaften eines echten Kristallgitters. Sie ist jedoch makroskopisch, also klassisch, und die einzelnen Partikel sind viel besser beobachtbar als etwa Atome in kondensierter Materie. Das macht sie zu idealen Modellsystemen für die Erforschung von Kristallen, Phasenübergängen oder von Flüssigkeiten. Komplexe Plasmen zeigen darüber hinaus ganz neue Eigenschaften.

  18. Detektion von fahrspuren und kreuzungen auf nichtmarkierten straen zum autonomen führen von fahrzeugen

    NASA Astrophysics Data System (ADS)

    Vacek, Stefan; Bürkle, Cornelius; Schröder, Joachim; Dillmann, Rüdiger

    Das Wissen über Position und Verlauf der Straße ist eine der wichtigsten Informationen, die zum Führen autonomer Straßenfahrzeuge benötigt wird. Die meisten Arbeiten gehen davon aus, dass Markierungen auf der Straße vorhanden sind, die die Erkennung enorm erleichtern. Üblicherweise werden die Fahrbahnränder detektiert und die Fahrspur mit Hilfe eines Kaiman-Filters geschätzt [1]. Andere Arbeiten verwenden zusätzlich die Straßenfarbe und kombinieren die verschiedenen Hinweise in einem Partikel-Filter [2]. Ein allgemeiner Überblick über Verfahren zur Fahrspurdetektion findet sich in [3].

  19. Lattice Location of 12B in Single-Crystal Ni3Al Studied by -Radiation Detected NMR

    NASA Astrophysics Data System (ADS)

    Fischer, B.; Ittermann, B.; Diehl, E.; Dippel, R.; Ergezinger, K. H.; Frank, H.-P.; Jäger, E.; Seelinger, W.; Sulzer, G.; Ackermann, H.; Stöckmann, H.-J.; Bohn, H. G.

    -radiation detected nuclear magnetic resonance was applied to determine the location of 12B probe nuclei in a Ni3Al single crystal. Combining our results with those of channeling experiments it turned out that more than 90% of the 12B ions occupy the octahedral interstitial site with six Ni ions as nearest neighbours.Translated AbstractGitterplatzbestimmung von 12B im Ni3Al-Einkristall mittels -strahlungsdetektierter NMRDer Einbauplatz des Sondenkerns 12B im Ni3Al-Einkristall wurde durch Kernresonanz mit β-Strahlungsnachweis bestimmt. Aus der Kombination mit Ergebnissen von Gitterführungsexperimenten ergab sich, daß über 90% der 12B-Ionen auf oktaedrischen Zwischengitterplätzen mit sechs Ni-Ionen als nächsten Nachbarn eingebaut werden.

  20. Semantic Desktop

    NASA Astrophysics Data System (ADS)

    Sauermann, Leo; Kiesel, Malte; Schumacher, Kinga; Bernardi, Ansgar

    In diesem Beitrag wird gezeigt, wie der Arbeitsplatz der Zukunft aussehen könnte und wo das Semantic Web neue Möglichkeiten eröffnet. Dazu werden Ansätze aus dem Bereich Semantic Web, Knowledge Representation, Desktop-Anwendungen und Visualisierung vorgestellt, die es uns ermöglichen, die bestehenden Daten eines Benutzers neu zu interpretieren und zu verwenden. Dabei bringt die Kombination von Semantic Web und Desktop Computern besondere Vorteile - ein Paradigma, das unter dem Titel Semantic Desktop bekannt ist. Die beschriebenen Möglichkeiten der Applikationsintegration sind aber nicht auf den Desktop beschränkt, sondern können genauso in Web-Anwendungen Verwendung finden.

  1. Modeling Particle Acceleration and Transport at CIRs

    NASA Astrophysics Data System (ADS)

    Li, G.; Zhao, L.; Ebert, R. W.; Desai, M. I.; Dayeh, M. A.; Mason, G. M.; Chen, Y.; Wu, Z.

    2014-12-01

    CIRs are a major site for particle acceleration during solar minimum. Earlier Ulysses observations have found that particles can be accelerated at both the forward and the reverse shocks that often form at a few AUs. The accelerated particles then propagate back to the Earth along Parker's field line. Theoretical calculations predicted a modulation of the spectrum at low energies, qualitatively agreed with obsevations at 1 AU. However, this picture was recently challenged by STEREO observations, where local accelerations near 1 AU were inferred in many events. In this work, we perform a detailed numerical calculation to study particle acceleration and transport in one CIR event which was observed by both ACE and STEREO spacecraft. We obtain particle currents at different heliocentric distances and different longitudes, as well as particle anisotropy. These values are compared with observations and the implication on the acceleration site and the interplanetary turbulence spectrum is discussed.

  2. [Up-to-date experience with the international classification system Bethesda 2010 for thyroid fine-needle aspirate: a review].

    PubMed

    Ludvíková, Marie; Kholová, Ivana

    2014-07-01

    The Bethesda System for Reporting Thyroid Cytopathology (BSRTC) was introduced in thyroid fine needle aspiration cytology (FNAC) in 2010. A six-tier system is generally accepted. Bethesda categories include morphologic description, risk of malignancy and follow-up suggestions in each group. The system has its advantages and disadvantages, that are discussed. The most problematic are the categories of "Atypia of undetermined significance" or "Follicular lesion of undetermined significance" (AUS/FLUS). The group is heterogenous and overused thus far. The possibilities of its improvement are discussed. The Bethesda system does not include any prognostic and predictive markers. However, they represent the promising direction in the improved version of the BSRTC. Novel molecular methods and alternative techniques such as core needle biopsy are briefly discussed. PMID:25186598

  3. Wie Deutschland zum Leitanbieter für Elektromobilität werden kann, acatech BEZIEHT POSITION

    NASA Astrophysics Data System (ADS)

    Rund drei Viertel der anthropogen bedingten CO2-Emissionen werden weltweit in Ballungsräumen verursacht, wovon ein guter Teil auf die kaum abschätzbare Zahl täglicher Personen- und Güterverkehre mit Nahdistanzen zurückzuführen ist. Der Verkehrssektor in Deutschland ist für ein Viertel des Endenergieverbrauchs verantwortlich und trägt mit einem knappen Fünftel der Emissionen in nicht unerheblichem Umfang zum Ausstoß von Treibhausgasen bei. Der Straßenverkehr macht innerhalb des Gesamtverkehrs mehr als zwei Drittel der Emissionen aus, europaweit sind es 80 Prozent. Hier wird langfristig sogar mit einer Verdopplung des Energieverbrauchs im Straßensektor gerechnet.

  4. Organisation des gesundheitlichen Verbraucherschutzes auf Bundesebene

    NASA Astrophysics Data System (ADS)

    Tschiersky-Schöneburg, Helmut; Büttner, Antje

    Zahlreiche Krisen wie Dioxin belastete Futtermittel, die missbräuchliche Verwendung von Antibiotika in der Schweinemast und nicht zuletzt das Auftreten von BSE in Deutschland erschütterten Ende der neunziger Jahre das Vertrauen der Bürger in die Sicherheit der Lebensmittel. Mit dem Weißbuch zur Lebensmittelsicherheit, das im Januar 2000 herausgegeben wurde, hatte die Europäische Kommission ihre Erfahrungen aus dem BSE-Geschehen in ein neues Konzept für den Verbraucherschutz eingearbeitet. Kernstücke des Konzepts sind die ganzheitliche Betrachtung der Lebensmittelsicherheit von der landwirtschaftlichen Erzeugung bis zum Verzehr und der Anspruch nach Transparenz und Unabhängigkeit der Risikobewertung.

  5. MediMax Elektronik-Marktkette

    NASA Astrophysics Data System (ADS)

    Die Elektronikkette MediMax setzt auf Server Based Computing mit Windows Server 2003® und Thin Clients. Mit über 100 Filialen ist MediMax die erfolgreiche Fachmarktlinie der ElectronicPartner-Verbundgruppe in Deutschland. Die Zugehörigkeit zum Mutterverbund garantiert den Franchisenehmern der Elektronikkette eine schnelle Warenversorgung und günstige Einkaufskonditionen. Über 50.000 Artikel zahlreicher namhafter Markenhersteller und unterschiedlicher Preisklassen sind ständig abrufbar. Darüber hinaus profitieren die Filialen von einer zentralen Organisation und Betreuung ihrer IT. Von Düsseldorf aus administriert ein internes Supportteam die Arbeitsplätze aller Standorte und stellt außerdem die Warenwirtschaftslösung zur Verfügung. Dank der Umstellung auf eine moderne Server Based Computing-Umgebung sind Wartung und Support künftig so effizient wie nie zuvor.

  6. Darwin, Engels und die Rolle der Arbeit in der biologischen und kulturellen Evolution des Menschen

    NASA Astrophysics Data System (ADS)

    Reichholf, Josef H.

    Im Jahre 1876, 5 Jahre nach Erscheinen von Darwins Buch über die Evolution des Menschen und die sexuelle Selektion (Darwin 1871), veröffentlichte Friedrich Engels den berühmt gewordenen Essay "Anteil der Arbeit an der Menschwerdung des Affen“ (Engels 1876). Die Kernfrage darin lautet in Kurzform: Warum hat der Mensch eigentlich ein Bedürfnis nach Arbeit? Engels Antwort wird nachfolgend näher betrachtet und vom gegenwärtigen Kenntnisstand aus beurteilt. Wie sich zeigen wird, beantworten seine Überlegungen die Frage nicht wirklich. Sie ist weiterhin offen. Es können lediglich einige zusätzliche Anhaltspunkte zur Diskussion gestellt werden. Angesichts des drängenden Problems millionenfacher Arbeitslosigkeit und der Forderungen nach einem "Grundrecht auf Arbeit“ kommt den Überlegungen zum möglichen Ursprung des Bedürfnisses nach Arbeit mehr als nur akademisches Interesse zu.

  7. Solidified liquid layer model expands the application fields of quartz crystal microbalance.

    PubMed

    Fu, Long; Chen, Yanyan; Ma, Hongwei

    2012-05-14

    The application of a quartz crystal microbalance (QCM) in liquid is hindered by the complexity of data analysis. Recently, a "solidified liquid layer" (SLL) model has been proposed to simplify the data analysis. Here, missing evidence to support the SLL model is provided: 1) the SLL model is responsive to the density change of the liquid environment, 2) thickness values from the SLL model (T(SLL) ) are in agreement with values measured by ellipsometry. The SLL model predicts that a 0.18 nm change of T(SLL) will lead to a 1 Hz signal, which is the resolution that most commercial QCMs could easily achieve. Using the SLL model, Au-S bond breakage has been successful. Biosensor applications are also being designed according to the SLL model. It is believed that with these results, the SLL model will bring QCM back to the radar screen of scientists. PMID:22492463

  8. Factors Affecting the Outcomes of Carpal Tunnel Surgery: A Review.

    PubMed

    Zyluk-Gadowska, P; Zyluk, A

    2016-08-01

    Ziel der vorliegenden Arbeit war es, unter Berücksichtigung der in Pubmed und Medline veröffentlichten Ergebnisse nach Eingriffen am Karpalkanal zu ermitteln, inwieweit ausgewählte Faktoren wie das Patientenalter, die Dauer der Symptome, die Ausprägung der klinischen und elektrophysiologischen Befunde, das Vorliegen von Begleiterkrankungen und medikolegale Momente die Ergebnisse beeinflussen. Letztlich konnte für keinen der zahlreichen untersuchten Faktoren ein signifikanter Einfluss auf das Langzeitergebnis nachgewiesen werden. Bestehen die Beschwerden länger, sind die klinischen und elektrophysiologischen Befunde ausgeprägter und liegen Begleiterkrankungen vor, so fallen die Ergebnisse weniger gut aus, was darauf hindeutet, dass die betroffenen Patienten etwas weniger von der Operation profitieren. Nur bei Vorliegen von medikolegalen Faktoren wie Rechtsstreit oder Schadenersatzansprüchen lässt sich definitiv ein schlechtes Ergebnis voraussagen. PMID:27580438

  9. Photoelectron spectroscopic study on the electronic structures of the dental gold alloys and their interaction with L-cysteine

    SciTech Connect

    Ogawa, Koji; Takahashi, Kazutoshi; Azuma, Junpei; Kamada, Masao; Tsujibayashi, Toru; Ichimiya, Masayoshi; Fujimoto, Hitoshi; Sumimoto, Michinori

    2011-11-15

    The valence electronic structures of the dental gold alloys, type 1, type 3, and K14, and their interaction with L-cysteine have been studied by ultraviolet photoelectron spectroscopy with synchrotron radiation. It was found that the electronic structures of the type-1 and type-3 dental alloys are similar to that of polycrystalline Au, while that of the K14 dental alloy is much affected by Cu. The peak shift and the change in shape due to alloying are observed in all the dental alloys. It is suggested that the new peak observed around 2 eV for the L-cysteine thin films on all the dental alloys may be due to the bonding of S 3sp orbitals with the dental alloy surfaces, and the Cu-S bond, as well as the Au-S and Au-O bonds, may cause the change in the electronic structure of the L-cysteine on the alloys.

  10. Gesammelte Werke / Collected Works

    NASA Astrophysics Data System (ADS)

    Schwarzschild, Karl; Voigt, Hans-Heinrich

    Der bekannte Astronom Karl Schwarzschild (1873-1916) gilt als der Begründer der Astrophysik und als hervorragender Forscher mit einer erstaunlichen Bandbreite seiner Interessen. Arbeiten zur Himmelsmechanik, Elektrodynamik und Relativitätstheorie weisen ihn als vorzüglichen Mathematiker und Physiker auf der Höhe seiner Zeit aus. Untersuchungen zur Photographischen Photometrie, Optik und Spektroskopie zeigen den versierten Beobachter, der sein Meßinstrumentarium beherrscht, und schließlich arbeitete Schwarzschild als Astrophysiker an Sternatmosphären, Kometen, Struktur und Dynamik von Sternsystemen. Die in seinem kurzen Leben entstandene Fülle an wissenschaftlichen Arbeiten ist in drei Bänden der Gesamtausgabe gesammelt, ergänzt durch biographisches Material, Annotationen von Fachleuten und einen Essay des Nobelpreisträgers S. Chandrasekhar.

  11. Gesammelte Werke / Collected Works

    NASA Astrophysics Data System (ADS)

    Schwarzschild, Karl; Voigt, Hans-Heinrich

    Der bekannte Astronom Karl Schwarzschild (1873-1916) gilt als der Begründer der Astrophysik und als hervorragender Forscher mit einer erstaunlichen Bandbreite seiner Interessen. Arbeiten zur Himmelsmechanik, Elektrodynamik und Relativitätstheorie weisen ihn als vorzüglichen Mathematiker und Physiker auf der Höhe seiner Zeit aus. Untersuchungen zur Photographischen Photometrie, Optik und Spektroskopie zeigen den versierten Beobachter, der sein Meßinstrument beherrscht, und schließlich arbeitete Schwarzschild als Astrophysiker und an Sternatmosphären, Kometen, Struktur und Dynamik von Sternsystemen. Die in seinem kurzen Leben entstandene Fülle an wissenschaftlichen Arbeiten ist in drei Bänden der Gesamtausgabe gesammelt, ergänzt durch biographisches Material und ein Essay des Nobelpreisträgers S. Chandrasekhar im ersten Band, und Annotationen von Fachleuten in jedem der drei Bände.

  12. Gesammelte Werke / Collected Works

    NASA Astrophysics Data System (ADS)

    Schwarzschild, Karl; Voigt, Hans-Heinrich

    Der bekannte Astronom Karl Schwarzschild (1873-1916) gilt als der Begründer der Astrophysik und als hervorragender Forscher mit einer erstaunlichen Bandbreite seiner Interessen. Arbeiten zur Himmelsmechanik, Elektrodynamik und Relativitätstheorie weisen ihn als vorzüglichen Mathematiker und Physiker seiner Zeit aus. Untersuchungen zur Photographischen Photometrie, Optik und Spektroskopie zeigen den versierten Beobachter, der sein Meßinstrument beherrscht. Schließlich arbeitete Schwarzschild als Astrophysiker und an Sternatmosphären, Kometen, Struktur und Dynamik von Sternsystemen. Die in seinem kurzen Leben entstandene Fülle von wissenschafltichen Arbeiten ist in drei Bänden der Gesamtausgabe gesammelt, ergänzt durch biographisches Material und ein Essay des Nobelpreisträgers S. Chandrasekhar und Annotationen von Fachleuten in jedem der drei Bände.

  13. An X-Ray Microlensing Test of the Au-Scale Central Structure of the Quadruple Quasar 2237+0305

    NASA Astrophysics Data System (ADS)

    Mineshige, Shin

    2011-09-01

    We propose Chandra observations of the gravitationally lensed quasar Q2237+0305 during a microlensing event to reveal its AU scale central structure. The quasar being monitored from the ground regularly to ascertain the onset of the event. As it occurs, we will measure X-ray spectral variations with Chandra and compare with those taken before and after the event. Since a small region of the quasar accretion disk is strongly magnified during the event, we will be able to limit the mass contained on scales of several AUs and to probe the physical properties of X-ray emitting gas in the vicinity of the black hole. Together with ground-based telescope, we can resolve the quasar emission regions at multiple wavelength. This provides a critical test of quasar accretion disk theories.

  14. An X-Ray Microlensing Test of the Au-Scale Central Structure of the Quadruple Quasar 2237+0305

    NASA Astrophysics Data System (ADS)

    Mineshige, Shin

    2008-09-01

    We propose Chandra observations of the gravitationally lensed quasar Q2237+0305 during a microlensing event to reveal its AU scale central structure. The quasar is being monitored from the ground regularly to ascertain the onset of the event. As it occurs, we will measure X-ray spectral variations with Chandra and compare with those taken before and after the event. Since a small region of the quasar accretion disk is strongly magnified during the event, we will be able to limit the mass contained on scales of several AUs and to probe the physical properties of X-ray emitting gas in the vicinity of the black hole. Together with ground-based telescopes, we can resolve the quasar emission regions at multiple wavelengths. This provide a critical test of quasar accretion disk theories.

  15. Biokompatible Implantate und Neuentwicklungen in der Gynäkologie

    NASA Astrophysics Data System (ADS)

    Jacobs, Volker R.; Kiechle, Marion

    Für den Einsatz in der Gynäkologie stehen heute eine Vielzahl unterschiedlicher, biokompatibler Materialien und Implantate zur Verfügung. Auf eine Auswahl soll hier näher eingegangen werden, die die verschiedenen Materialien und Bauweisen repräsentieren. So sind Brustimplantate seit fast vier Jahrzehnten im Gebrauch für die Brustvergrösserung und den Brustwiederaufbau. Material, Bauweisen und medizinische Aspekte einschliesslich der kontroversen Diskussion um Silikon werden im folgenden erläutert. Neuere Entwicklungen von Verhütungstechniken für permanente Sterilisation wie den Filshie ClipTM für transabdominalen und den STOPTM für intraluminalen Verschluss der Eileiter oder die intrauterin plazierte Hormonspirale MirenaTM für zeitlich begrenzte Verhütung werden beschrieben. Eine neue Perspektive zur Verhinderung postoperativer intraabdominaler Adhäsionen stellt Spray-GelTM, ein Zweikomponenten Hydrogel aus Polyethylenglykol, dar.

  16. IntegraTUM Teilprojekt E-Mail: Rezentralisierung von E-Mail-Services

    NASA Astrophysics Data System (ADS)

    Diehn, Max; Haarer, Ado; Schreiner, Alexander; Storz, Michael

    Das Teilprojekt E-Mail hatte ursprünglich die Aufgabe einen zentralen Mailservice mit verteilter Administration der Mailadressen für die TUM aufzubauen und diesen durch Anti-Spam- und Anti-Viren-Maßnahmen zu schützen. Auf diesen Mailservice sollten sowohl die am LRZ gehosteten Maildomains als auch die vielen lokal betriebenen Mailserver - soweit von deren Betreibern gewünscht - migriert werden. Neben einigen Rückschlägen und Hindernissen kam es im Laufe des Projektes auch zu einer Änderung der Anforderungen, sodass zum Ende des Projektes statt eines reinen Mailsystems ein Doppelsystem mit "shared SMTP address space" bestehend aus einem klassischen Message-Store mit POP/IMAP-Zugriff auf Basis von Postfix + Dovecot und einem Groupware-System auf Basis von Microsoft Exchange in Produktion ging, wobei jeder Mitarbeiter und Student der TUM wählen kann, auf welchem der beiden Systeme sich seine Mailbox befindet.

  17. Demokrit - Planck

    NASA Astrophysics Data System (ADS)

    Rompe, Robert; Treder, Hans-Jürgen

    Es gibt eine Physik, die an die Konstante h gebunden ist und die mit der Atomistik zusammenhängt. Diese h-Physik geht eindeutig auf Planck zurück. Aber, aus dieser Physik folgt die Atomistik als Existenz lokalisierter geladener Teilchen unterschiedlichen Massen nicht, vor allem nicht die des Ladungsquants, so daß also Demokrit mehr behauptet hat, als die Quantenphysik zu beantworten kompetent ist.Translated AbstractDemokrit - PlanckA branch of physics exists closely linked to the constant h and associated with atomism. It is this h-physics that Planck originated. But atomism like existence of localized, charged particles with different masses does not follow from this physics, especially the charge quant. Hence Demokrit asserted more then quantum physics is competent to answer.

  18. Tetrairon(III) single-molecule magnet monolayers on gold: insights from ToF-SIMS and isotopic labeling.

    PubMed

    Totaro, Pasquale; Poggini, Lorenzo; Favre, Annaick; Mannini, Matteo; Sainctavit, Philippe; Cornia, Andrea; Magnani, Agnese; Sessoli, Roberta

    2014-07-29

    To work as magnetic components in molecular electronics and spintronics, single-molecule magnets (SMMs) must be reliably interfaced with metals. The organization on gold of a Fe4 SMM carrying two acetyl-protected thiol groups has been studied by exploiting the surface sensitivity of time-of-flight secondary ion mass spectrometry (ToF-SIMS), additionally powered by the use of an isotopic labeling strategy. Deposition from millimolar dichloromethane solutions results in a higher surface coverage and better packed monolayers as compared with previous protocols based on more diluted solutions. Fe4 complexes are chemically tethered to the surface via a single Au-S bond while they still contain an intact SAc group. PMID:25000391

  19. The Northern HIPASS catalogue - data presentation, completeness and reliability measures

    NASA Astrophysics Data System (ADS)

    Wong, O. I.; Ryan-Weber, E. V.; Garcia-Appadoo, D. A.; Webster, R. L.; Staveley-Smith, L.; Zwaan, M. A.; Meyer, M. J.; Barnes, D. G.; Kilborn, V. A.; Bhathal, R.; de Blok, W. J. G.; Disney, M. J.; Doyle, M. T.; Drinkwater, M. J.; Ekers, R. D.; Freeman, K. C.; Gibson, B. K.; Gurovich, S.; Harnett, J.; Henning, P. A.; Jerjen, H.; Kesteven, M. J.; Knezek, P. M.; Koribalski, B. S.; Mader, S.; Marquarding, M.; Minchin, R. F.; O'Brien, J.; Putman, M. E.; Ryder, S. D.; Sadler, E. M.; Stevens, J.; Stewart, I. M.; Stootman, F.; Waugh, M.

    2006-10-01

    The Northern HIPASS catalogue (NHICAT) is the northern extension of the HIPASS catalogue, HICAT. This extension adds the sky area between the declination (Dec.) range of +2° < δ < +25°30' to HICAT's Dec. range of -90° < δ < +2°. HIPASS is a blind HI survey using the Parkes Radio Telescope covering 71 per cent of the sky (including this northern extension) and a heliocentric velocity range of -1280 to 12700kms-1. The entire Virgo Cluster region has been observed in the Northern HIPASS. The galaxy catalogue, NHICAT, contains 1002 sources with vhel > 300kms-1. Sources with -300 < vhel < 300kms-1 were excluded to avoid contamination by Galactic emission. In total, the entire HIPASS survey has found 5317 galaxies identified purely by their HI content. The full galaxy catalogue is publicly available at http://hipass.aus-vo.org.

  20. Leitbilder und Handlungsstrategien für die Raumentwicklung in Deutschland. Entwicklungs-, Umsetzungs- und Fortschreibungsprozess der Bund-Länder-Strategie für Städte und Regionen

    NASA Astrophysics Data System (ADS)

    Issaoui, Mariam; Sinz, Manfred

    2010-09-01

    Die Ministerkonferenz für Raumordnung stellte im Mai 2010 fest, dass sich die „Leitbilder und Handlungsstrategien für die Raumentwicklung in Deutschland“ (2006) bewährt haben und bei der Gestaltung der räumlichen Entwicklung umgesetzt werden. Um die Leitbilder den sich verändernden wirtschaftlichen, sozialen und naturräumlichen Rahmenbedingungen anzupassen und die Erkenntnisse aus dem bisherigen Diskussions- und Umsetzungsprozess in Politik und Praxis einzubeziehen, sind sie zu ergänzen und weiterzuentwickeln. Im Mittelpunkt der Fortschreibung werden die Themen „Partnerschaften und Strategien für Stadtregionen und ländliche Räume“, „Mobilität und Logistik“ sowie „Klimaschutz und Energieversorgung“ stehen.