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Sample records for rhodobacter sphaeroides growing

  1. The architecture of Rhodobacter sphaeroides chromatophores.

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    Scheuring, Simon; Nevo, Reinat; Liu, Lu-Ning; Mangenot, Stéphanie; Charuvi, Dana; Boudier, Thomas; Prima, Valerie; Hubert, Pierre; Sturgis, James N; Reich, Ziv

    2014-08-01

    The chromatophores of Rhodobacter (Rb.) sphaeroides represent a minimal bio-energetic system, which efficiently converts light energy into usable chemical energy. Despite extensive studies, several issues pertaining to the morphology and molecular architecture of this elemental energy conversion system remain controversial or unknown. To tackle these issues, we combined electron microscope tomography, immuno-electron microscopy and atomic force microscopy. We found that the intracellular Rb. sphaeroides chromatophores form a continuous reticulum rather than existing as discrete vesicles. We also found that the cytochrome bc1 complex localizes to fragile chromatophore regions, which most likely constitute the tubular structures that interconnect the vesicles in the reticulum. In contrast, the peripheral light-harvesting complex 2 (LH2) is preferentially hexagonally packed within the convex vesicular regions of the membrane network. Based on these observations, we propose that the bc1 complexes are in the inter-vesicular regions and surrounded by reaction center (RC) core complexes, which in turn are bounded by arrays of peripheral antenna complexes. This arrangement affords rapid cycling of electrons between the core and bc1 complexes while maintaining efficient excitation energy transfer from LH2 domains to the RCs. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Enhancement of Rhodobacter sphaeroides growth and carotenoid production through biostimulation.

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    Liu, Shuli; Zhang, Guangming; Li, Xiangkun; Wu, Pan; Zhang, Jie

    2015-07-01

    Bacillus thuringiensis/cereus L2 was added as a biostimulant to enhance the biomass accumulation and carotenoid yield of Rhodobacter sphaeroides using wastewater as the culturing medium. Results showed that biostimulation could significantly enhance the R. sphaeroides biomass production and carotenoid yield. The optimal biostimulant proportion was 40 μL (about 6.4×10(5) CFU). Through the use of biostimulation, chemical oxygen demand removal, R. sphaeroides biomass production, carotenoid concentration, and carotenoid yield were improved by 178%, 67%, 214%, and 70%, respectively. Theoretical analysis revealed that there were two possible reasons for such increases. One was that biostimulation enhanced the R. sphaeroides wastewater treatment efficiency. The other was that biostimulation significantly decreased the peroxidase activity in R. sphaeroides. The results showed that the highest peroxidase activity dropped by 87% and the induction ratio of the RSP_3419 gene was 3.1 with the addition of biostimulant. The enhanced carotenoid yield in R. sphaeroides could thus be explained by a decrease in peroxidase activity. Copyright © 2015. Published by Elsevier B.V.

  3. Wheat straw degradation and production of alternative substrates for nitrogenase of Rhodobacter sphaeroides.

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    Dziga, Dariusz; Jagiełło-Flasińska, Dominika

    2015-01-01

    Cellulose is a major component of plant biomass and could be applied in the production of biofuels, especially bioethanol. An alternative approach is production of a clean fuel - hydrogen from cellulosic biomass. In this paper an innovatory model of cellulosic waste degradation has been proposed to verify the possibility of utilization of cellulose derivatives by purple non-sulfur bacteria. The concept is based on a two-step process of wheat straw conversion by bacteria in order to obtain an organic acid mixture. In the next stage such products are consumed by Rhodobacter sphaeroides, the known producer of hydrogen. It has been documented that Cellulomonas uda expresses cellulolytic activity in the presence of wheat straw as an only source of carbon. R. sphaeroides applied in this research can effectively consume organic acids released from straw by C. uda and Lactobacillus rhamnosus and is able to grow in the presence of these substrates. Additionally, an increased nitrogenase activity of R. sphaeroides has been indicated when bacteria were cultivated in the presence of cellulose derivatives which suggests that hydrogen production occurs.

  4. The two photocycles of photoactive yellow protein from Rhodobacter sphaeroides.

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    Haker, Andrea; Hendriks, Johnny; van Stokkum, Ivo H M; Heberle, Joachim; Hellingwerf, Klaas J; Crielaard, Wim; Gensch, Thomas

    2003-03-07

    The absorption spectrum of the photoactive yellow protein from Rhodobacter sphaeroides (R-PYP) shows two maxima, absorbing at 360 nm (R-PYP(360)) and 446 nm (R-PYP(446)), respectively. Both forms are photoactive and part of a temperature- and pH-dependent equilibrium (Haker, A., Hendriks, J., Gensch, T., Hellingwerf, K. J., and Crielaard, W. (2000) FEBS Lett. 486, 52-56). At 20 degrees C, for PYP characteristic, the 446-nm absorbance band displays a photocycle, in which the depletion of the 446-nm ground state absorption occurs in at least three phases, with time constants of <30 ns, 0.5 micros, and 17 micros. Intermediates with both blue- and red-shifted absorption maxima are transiently formed, before a blue-shifted intermediate (pB(360), lambda(max) = 360 nm) is established. The photocycle is completed with a monophasic recovery of the ground state with a time constant of 2.5 ms. At 7 degrees C these photocycle transitions are slowed down 2- to 3-fold. Upon excitation of R-PYP(360) with a UV-flash (330 +/- 50 nm) a species with a difference absorption maximum at approximately 435 nm is observed that returns to R-PYP(360) on a minute time scale. Recovery can be accelerated by a blue light flash (450 nm). R-PYP(360) and R-PYP(446) differ in their overall protein conformation, as well as in the isomerization and protonation state of the chromophore, as determined with the fluorescent polarity probe Nile Red and Fourier Transform Infrared spectroscopy, respectively.

  5. Hydrogen Production by Co-cultures of Rhizopus oryzae and a Photosynthetic Bacterium, Rhodobacter sphaeroides RV

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    Asada, Yasuo; Ishimi, Katsuhiro; Nagata, Yoko; Wakayama, Tatsuki; Miyake, Jun; Kohno, Hideki

    Hydrogen production with glucose by using co-immobilized cultures of a fungus, Rhizopus oryzae NBRC5384, and a photosynthetic bacterium, Rhodobacter sphaeroides RV, in agar gels was studied. The co-immobilized cultures converted glucose to hydrogen via lactate in a high molar yield of about 8moles of hydrogen per glucose at a maximum under illuminated conditions.

  6. Nitrite and Nitrous Oxide Reductase Regulation by Nitrogen Oxides in Rhodobacter sphaeroides f. sp. denitrificans IL106

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    Sabaty, Monique; Schwintner, Carole; Cahors, Sandrine; Richaud, Pierre; Verméglio, Andre

    1999-01-01

    We have cloned the nap locus encoding the periplasmic nitrate reductase in Rhodobacter sphaeroides f. sp. denitrificans IL106. A mutant with this enzyme deleted is unable to grow under denitrifying conditions. Biochemical analysis of this mutant shows that in contrast to the wild-type strain, the level of synthesis of the nitrite and N2O reductases is not increased by the addition of nitrate. Growth under denitrifying conditions and induction of N oxide reductase synthesis are both restored by the presence of a plasmid containing the genes encoding the nitrate reductase. This demonstrates that R. sphaeroides f. sp. denitrificans IL106 does not possess an efficient membrane-bound nitrate reductase and that nitrate is not the direct inducer for the nitrite and N2O reductases in this species. In contrast, we show that nitrite induces the synthesis of the nitrate reductase. PMID:10498715

  7. Regulation of Gene Expression by PrrA in Rhodobacter sphaeroides 2.4.1: Role of Polyamines and DNA Topology▿

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    Eraso, Jesus M.; Kaplan, Samuel

    2009-01-01

    In the present study, we show in vitro binding of PrrA, a global regulator in Rhodobacter sphaeroides 2.4.1, to the PrrA site 2, within the RSP3361 locus. Specific binding, as shown by competition experiments, requires the phosphorylation of PrrA. The binding affinity of PrrA for site 2 was found to increase 4- to 10-fold when spermidine was added to the binding reaction. The presence of extracellular concentrations of spermidine in growing cultures of R. sphaeroides gave rise to a twofold in...

  8. Electronic pathway in reaction centers from Rhodobacter sphaeroides and Chloroflexus aurantiacus.

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    Pudlak, Michal; Pincak, Richard

    2010-06-01

    The reaction centers (RC) of Chloroflexus aurantiacus and Rhodobacter sphaeroidesH(M182)L mutant were investigated. Prediction for electron transfer (ET) at very low temperatures was also performed. To describe the kinetics of the C. aurantiacus RCs, the incoherent model of electron transfer was used. It was shown that the asymmetry in electronic coupling parameters must be included to explain the experiments. For the description of R. sphaeroidesH(M182)L mutant RCs, the coherent and incoherent models of electron transfer were used. These two models are discussed with regard to the observed electron transfer kinetics. It seems likely that the electron transfer asymmetry in R. sphaeroides RCs is caused mainly by the asymmetry in the free energy levels of L- and M-side cofactors. In the case of C. aurantiacus RCs, the unidirectionality of the charge separation can be caused mainly by the difference in the electronic coupling parameters in two branches.

  9. Gene co-expression network analysis in Rhodobacter capsulatus and application to comparative expression analysis of Rhodobacter sphaeroides

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    Pena-Castillo, Lourdes; Mercer, Ryan; Gurinovich, Anastasia; Callister, Stephen J.; Wright, Aaron T.; Westbye, Alexander; Beatty, J. T.; Lang, Andrew S.

    2014-08-28

    The genus Rhodobacter contains purple nonsulfur bacteria found mostly in freshwater environments. Representative strains of two Rhodobacter species, R. capsulatus and R. sphaeroides, have had their genomes fully sequenced and both have been the subject of transcriptional profiling studies. Gene co-expression networks can be used to identify modules of genes with similar expression profiles. Functional analysis of gene modules can then associate co-expressed genes with biological pathways, and network statistics can determine the degree of module preservation in related networks. In this paper, we constructed an R. capsulatus gene co-expression network, performed functional analysis of identified gene modules, and investigated preservation of these modules in R. capsulatus proteomics data and in R. sphaeroides transcriptomics data. Results: The analysis identified 40 gene co-expression modules in R. capsulatus. Investigation of the module gene contents and expression profiles revealed patterns that were validated based on previous studies supporting the biological relevance of these modules. We identified two R. capsulatus gene modules preserved in the protein abundance data. We also identified several gene modules preserved between both Rhodobacter species, which indicate that these cellular processes are conserved between the species and are candidates for functional information transfer between species. Many gene modules were non-preserved, providing insight into processes that differentiate the two species. In addition, using Local Network Similarity (LNS), a recently proposed metric for expression divergence, we assessed the expression conservation of between-species pairs of orthologs, and within-species gene-protein expression profiles. Conclusions: Our analyses provide new sources of information for functional annotation in R. capsulatus because uncharacterized genes in modules are now connected with groups of genes that constitute a joint functional

  10. Biohydrogen Production from Tofu Wastewater with Glutamine Auxotrophic Mutant of Rhodobacter sphaeroides

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    Zheng, G. H.; Kang, Z. H.; Qian, Y. F.; Wang, L.; Zhou, Q.; Zhu, H. G.

    2008-02-01

    Hydrogen production from organic wastewater by photo-bacteria has been attracted more attention, not only because hydrogen is a clean energy, but also because it can be a process for organic wastewater pre-treatment. However NH4+, which normally is the integrant in organic wastewater, is the inhibitor to hydrogen production with photo-bacteria. In this study, the NH4+ effect on biohydrogen generation and nitrogenase activity of anoxygenic phototrophic bacteria-Rhodobacter sphaeroides was studied. Biohydrogen generation with wild-type R. sphaeroides was found to be more sensitive to NH4+ due to the obvious inhibition of NH4+ to its nitrogenase. For avoiding inhibition of NH4+ to biohydrogen generation of R. sphaeroides, a glutamine auxotrophic mutant R. sphaeroides AR-3 was obtained by EMS treatment. The mutant could generate biohydrogen efficiently in the medium with higher NH4+ concentration. Under suitable conditions, AR-3 produced biohydrogen from tofu wastewater with an average generation rate of 14.2 ml L-1h-1, it was increased by more than 100% compared with that from wild-type R. sphaeroides.

  11. Femtosecond charge separation in dry films of reaction centers of Rhodobacter sphaeroides and Chloroflexus aurantiacus.

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    Yakovlev, A G; Khmelnitsky, A Yu; Shuvalov, V A

    2012-05-01

    In this work, the influence of the crystallographic water on electron transfer between primary donor P and acceptor B(A) was studied in reaction centers (RCs) of the purple bacterium Rhodobacter sphaeroides and the green bacterium Chloroflexus aurantiacus. For this purpose, time constants and oscillations of charge separation kinetics are compared between dry film RCs and RCs in glycerol-water buffer at 90 K. A common result of the drying of Rba. sphaeroides and Cfx. aurantiacus RCs is slowing of the charge separation process, decrease in amplitude of the oscillatory components of the kinetics, and the depletion of its spectrum. Thus, the major time constant of stimulated emission decay of P* bacteriochlorophyll dimer at 940 nm is increased from 1.1 psec for water-containing Rba. sphaeroides RCs to 1.9 psec for dry films of Rba. sphaeroides RCs. An analogous increase from 3.5 to 4.2 psec takes place in Cfx. aurantiacus RCs. In dry films of Rba. sphaeroides RCs, the amplitude of coherent oscillations of the absorption band of monomeric bacteriochlorophyll B(A)(-) at 1020 nm is 1.8 times less for the 130-cm(-1) component and 2.3 times less for the 32-cm(-1) component than the analogous amplitudes for water-containing RCs. Measurements in the analogous band of Cfx. aurantiacus RCs show that strong decrease (~5-10 times) of the B(A)(-) absorption band and strong slowing (from ~0.8 to ~3 psec) of B(A)(-) accumulation together with ~3-fold decrease in oscillation amplitude occurs on drying of these RCs. The overtones of the 32-cm(-1) component disappeared from the oscillations of the kinetics at 940 and 1020-1028 nm after drying of the Rba. sphaeroides and Cfx. aurantiacus RCs. The results are in agreement with the results for GM203L mutant of Rba. sphaeroides, in which the HOH55 water molecule is sterically removed, and with the results for dry films of pheophytin-modified RCs of Rba. sphaeroides R-26 and for YM210W and YM210L Rba. sphaeroides mutant RCs. The data are

  12. BioBrick™ compatible vector system for protein expression in Rhodobacter sphaeroides.

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    Tikh, Ilya B; Held, Mark; Schmidt-Dannert, Claudia

    2014-04-01

    We report here the creation of a modular, plasmid-based protein expression system utilizing elements of the native Rhodobacter puf promoter in a BioBrick(TM)-based vector system with DsRed encoding a red fluorescent reporter protein. A suite of truncations of the puf promoter were made to assess the influence of different portions of this promoter on expression of heterologous proteins. The 3' end of puf was found to be particularly important for increasing expression, with transformants accumulating significant quantities of DsRed under both aerobic and anaerobic growth conditions. Expression levels of this reporter protein in Rhodobacter sphaeroides were comparable to those achieved in Escherichia coli using the strong, constitutive P lac promoter, thus demonstrating the robustness of the engineered system. Furthermore, we demonstrate the ability to tune the designed expression system by modulating cellular DsRed levels based upon the promoter segment utilized and oxygenation conditions. Last, we show that the new expression system is able to drive expression of a membrane protein, proteorhodopsin, and that membrane purifications from R. sphaeroides yielded significant quantities of proteorhodopsin. This toolset lays the groundwork for the engineering of multi-step pathways, including recalcitrant membrane proteins, in R. sphaeroides.

  13. The prevalence of gene duplications and their ancient origin in Rhodobacter sphaeroides 2.4.1

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    Cho Hyuk

    2010-12-01

    Full Text Available Abstract Background Rhodobacter sphaeroides 2.4.1 is a metabolically versatile organism that belongs to α-3 subdivision of Proteobacteria. The present study was to identify the extent, history, and role of gene duplications in R. sphaeroides 2.4.1, an organism that possesses two chromosomes. Results A protein similarity search (BLASTP identified 1247 orfs (~29.4% of the total protein coding orfs that are present in 2 or more copies, 37.5% (234 gene-pairs of which exist in duplicate copies. The distribution of the duplicate gene-pairs in all Clusters of Orthologous Groups (COGs differed significantly when compared to the COG distribution across the whole genome. Location plots revealed clusters of gene duplications that possessed the same COG classification. Phylogenetic analyses were performed to determine a tree topology predicting either a Type-A or Type-B phylogenetic relationship. A Type-A phylogenetic relationship shows that a copy of the protein-pair matches more with an ortholog from a species closely related to R. sphaeroides while a Type-B relationship predicts the highest match between both copies of the R. sphaeroides protein-pair. The results revealed that ~77% of the proteins exhibited a Type-A phylogenetic relationship demonstrating the ancient origin of these gene duplications. Additional analyses on three other strains of R. sphaeroides revealed varying levels of gene loss and retention in these strains. Also, analyses on common gene pairs among the four strains revealed that these genes experience similar functional constraints and undergo purifying selection. Conclusions Although the results suggest that the level of gene duplication in organisms with complex genome structuring (more than one chromosome seems to be not markedly different from that in organisms with only a single chromosome, these duplications may have aided in genome reorganization in this group of eubacteria prior to the formation of R. sphaeroides as gene

  14. The N Terminus of FliM Is Essential To Promote Flagellar Rotation in Rhodobacter sphaeroides

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    Poggio, Sebastian; Osorio, Aurora; Corkidi, Gabriel; Dreyfus, Georges; Camarena, Laura

    2001-01-01

    FliM is part of the flagellar switch complex. Interaction of this protein with phospho-CheY (CheY-P) through its N terminus constitutes the main information relay point between the chemotactic system and the flagellum. In this work, we evaluated the role of the N terminus of FliM in the swimming behavior of Rhodobacter sphaeroides. Strains expressing the FliM protein with substitutions in residues previously reported in Escherichia coli as being important for interaction with CheY showed an i...

  15. Expression and characteristics of the gene encoding azoreductase from Rhodobacter sphaeroides AS1.1737.

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    Bin, Yan; Jiti, Zhou; Jing, Wang; Cuihong, Du; Hongman, Hou; Zhiyong, Song; Yongming, Bao

    2004-07-01

    A gene that encodes a protein with azoreductase activity was obtained by PCR amplification from Rhodobacter sphaeroides AS1.1737. The enzyme, with a molecular weight of 18.7 kD, was heterologously expressed in Escherichia coli and its azoreductase activity was characterized. Furthermore, the reduction mechanism of azo dyes catalyzed by the azoreductase was studied in detail. The presence of a hydrazo-intermediate was identified, which provided a convincing evidence for the assumption that azo dyes were degraded via an incomplete reduction stage.

  16. Site-directed mutagenesis of substrate binding sites of azoreductase from Rhodobacter sphaeroides.

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    Liu, Guangfei; Zhou, Jiti; Wang, Jing; Yan, Bin; Li, Jingmei; Lu, Hong; Qu, Yuanyuan; Jin, Ruofei

    2008-05-01

    Comparison of three-dimensional structures of flavin-dependent azoreductases revealed two conserved loops around the flavin mononucleotide (FMN) cofactor. Tyr74, His75 and Lys109 in the two loops of azoreductase AZR from Rhodobacter sphaeroides were replaced with Trp, Asn and Ala/His by site-directed mutagenesis, respectively. The optimal pH values of K109H and H75N were pH 6, and those of K109A and Y74W were pH 9. The optimal temperature (30 degrees C) was not affected by mutation. Positively charged residues at position 109 is critical for the binding of methyl red. K109 might only be involved in the binding of the 2'-phosphate group of NADPH and have no effect on the binding of NADH. Y74W and H75N mutations decreased the binding of methyl red/nitrofurazone and had no affect on the binding of NADPH.

  17. Role of the Irr protein in the regulation of iron metabolism in Rhodobacter sphaeroides.

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    Verena Peuser

    Full Text Available In Rhizobia the Irr protein is an important regulator for iron-dependent gene expression. We studied the role of the Irr homolog RSP_3179 in the photosynthetic alpha-proteobacterium Rhodobacter sphaeroides. While Irr had little effect on growth under iron-limiting or non-limiting conditions its deletion resulted in increased resistance to hydrogen peroxide and singlet oxygen. This correlates with an elevated expression of katE for catalase in the Irr mutant compared to the wild type under non-stress conditions. Transcriptome studies revealed that Irr affects the expression of genes for iron metabolism, but also has some influence on genes involved in stress response, citric acid cycle, oxidative phosphorylation, transport, and photosynthesis. Most genes showed higher expression levels in the wild type than in the mutant under normal growth conditions indicating an activator function of Irr. Irr was however not required to activate genes of the iron metabolism in response to iron limitation, which showed even stronger induction in the absence of Irr. This was also true for genes mbfA and ccpA, which were verified as direct targets for Irr. Our results suggest that in R. sphaeroides Irr diminishes the strong induction of genes for iron metabolism under iron starvation.

  18. A molecular brake, not a clutch, stops the Rhodobacter sphaeroides flagellar motor

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    Pilizota, Teuta; Brown, Mostyn T.; Leake, Mark C.; Branch, Richard W.; Berry, Richard M.; Armitage, Judith P.

    2009-01-01

    Many bacterial species swim by employing ion-driven molecular motors that power the rotation of helical filaments. Signals are transmitted to the motor from the external environment via the chemotaxis pathway. In bidirectional motors, the binding of phosphorylated CheY (CheY-P) to the motor is presumed to instigate conformational changes that result in a different rotor-stator interface, resulting in rotation in the alternative direction. Controlling when this switch occurs enables bacteria to accumulate in areas favorable for their survival. Unlike most species that swim with bidirectional motors, Rhodobacter sphaeroides employs a single stop-start flagellar motor. Here, we asked, how does the binding of CheY-P stop the motor in R. sphaeroides—using a clutch or a brake? By applying external force with viscous flow or optical tweezers, we show that the R. sphaeroides motor is stopped using a brake. The motor stops at 27–28 discrete angles, locked in place by a relatively high torque, approximately 2–3 times its stall torque. PMID:19571004

  19. Comparison of reaction centers from Rhodobacter sphaeroides and rhodopseudomonas viridis: Overall archistecture and protein-pigment interactions

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    Elkabbani, Ossama; Chang, Chonghwan; Tiede, D.; Norris, J.; Schiffer, M. (Argonne National Lab., IL (United States))

    1991-06-04

    Photosynthetic reaction centers (RCs) from the photosynthetic bacteria Rhodobacter sphaeroides and Rhodopseudomonas viridis are protein complexes closely related in both structure and function. The structure of the Rps. viridis RC was used to determine the structure of the RC from Rb. sphaeroides. Small but meaningful differences between the positions of the helices and the cofactors in the two complexes were identified. The distances between helices A{sub L} adn A{sub M}, between B{sub L} and B{sub M}, and between bacteriopheophytins BP{sub L} and BP{sub M} are significantly shorter in Rps. viridis than they are in Rb. sphaeroides RCs. There are a number of differences in the amino acid residues that surround the cofactors; some of these residues form hydrogen bonds with the cofactors. Differences in chemical properties of the two RCs.

  20. Activity and characterization of mixed organic compounds extracted from Rhodobacter sphaeroides as alternative materials to serum for mammalian cell growth.

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    Lee, Hyun Jeong; Park, Ju-Yong; Yoo, Kye Sang; Yoon, Jihee; Kim, Yang-Hoon; Min, Jiho

    2013-11-01

    Photosynthetic microorganisms produce relatively large amounts of physiologically active materials which stimulate the physiological activity of other organisms. In this study, mammalian HeLa cells were cultured in different culture media which were Dulbecco's modified Eagle medium (DMEM) with newborn calf serum (NCS), and DMEM including different types of physiologically activating compounds (PACs) extracted from Rhodobacter sphaeroides grown under various culture conditions. R. sphaeroides was grown under the following five different culture conditions: anaerobically in the light, anaerobically in the dark and treated with dimethyl sulfoxide, aerobically in the dark for 48 h, in the light for 48 h, and in the light for 24 h and changed after previous culturing in the dark for 24 h. The growth of HeLa cell was measured by cell counting using a hemocytometer, and the fluorescent intensities of cellular lysosomes were measured to check the level of cellular stress caused by adding PACs. The growth of HeLa cells cultured in DMEM with PACs extracted from R. sphaeroides aerobically grown under dark conditions was enhanced compared to that of cells grown with NCS. We also found that a high concentration of pigments such as bacteriochlorophylls and carotenoids and a high concentration of arginine produced by R. sphaeroides aerobically grown in the dark were implicated in increased growth of the HeLa cells. Therefore, our results suggest that PACs extracted from R. sphaeroides aerobically cultured in dark conditions can enhance the physiological activity of mammalian cells and serve as nontoxic and bioavailable materials.

  1. Physiological roles for two periplasmic nitrate reductases in Rhodobacter sphaeroides 2.4.3 (ATCC 17025).

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    Hartsock, Angela; Shapleigh, James P

    2011-12-01

    The metabolically versatile purple bacterium Rhodobacter sphaeroides 2.4.3 is a denitrifier whose genome contains two periplasmic nitrate reductase-encoding gene clusters. This work demonstrates nonredundant physiological roles for these two enzymes. One cluster is expressed aerobically and repressed under low oxygen while the second is maximally expressed under low oxygen. Insertional inactivation of the aerobically expressed nitrate reductase eliminated aerobic nitrate reduction, but cells of this strain could still respire nitrate anaerobically. In contrast, when the anaerobic nitrate reductase was absent, aerobic nitrate reduction was detectable, but anaerobic nitrate reduction was impaired. The aerobic nitrate reductase was expressed but not utilized in liquid culture but was utilized during growth on solid medium. Growth on a variety of carbon sources, with the exception of malate, the most oxidized substrate used, resulted in nitrite production on solid medium. This is consistent with a role for the aerobic nitrate reductase in redox homeostasis. These results show that one of the nitrate reductases is specific for respiration and denitrification while the other likely plays a role in redox homeostasis during aerobic growth.

  2. Molecular cloning, overexpression and characterization of a novel water channel protein from Rhodobacter sphaeroides.

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    Mustafa Erbakan

    Full Text Available Aquaporins are highly selective water channel proteins integrated into plasma membranes of single cell organisms; plant roots and stromae; eye lenses, renal and red blood cells in vertebrates. To date, only a few microbial aquaporins have been characterized and their physiological importance is not well understood. Here we report on the cloning, expression and characterization of a novel aquaporin, RsAqpZ, from a purple photosynthetic bacterium, Rhodobacter sphaeroides ATCC 17023. The protein was expressed homologously at a high yield (∼20 mg/L culture under anaerobic photoheterotrophic growth conditions. Stopped-flow light scattering experiments demonstrated its high water permeability (0.17±0.05 cm/s and low energy of activation for water transport (2.93±0.60 kcal/mol in reconstituted proteoliposomes at a protein to lipid ratio (w/w of 0.04. We developed a fluorescence correlation spectroscopy based technique and utilized a fluorescent protein fusion of RsAqpZ, to estimate the single channel water permeability of RsAqpZ as 1.24 (±0.41 x 10(-12 cm(3/s or 4.17 (±1.38×10(10 H2O molecules/s, which is among the highest single channel permeability reported for aquaporins. Towards application to water purification technologies, we also demonstrated functional incorporation of RsAqpZ in amphiphilic block copolymer membranes.

  3. Bioremediation of petroleum hydrocarbon contaminated soil by Rhodobacter sphaeroides biofertilizer and plants.

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    Jiao, Haihua; Luo, Jinxue; Zhang, Yiming; Xu, Shengjun; Bai, Zhihui; Huang, Zhanbin

    2015-09-01

    Bio-augmentation is a promising technique for remediation of polluted soils. This study aimed to evaluate the bio-augmentation effect of Rhodobacter sphaeroides biofertilizer (RBF) on the bioremediation of total petroleum hydrocarbons (TPH) contaminated soil. A greenhouse pot experiment was conducted over a period of 120 days, three methods for enhancing bio-augmentation were tested on TPH contaminated soils, including single addition RBF, planting, and combining of RBF and three crop species, such as wheat (W), cabbage (C) and spinach (S), respectively. The results demonstrated that the best removal of TPH from contaminated soil in the RBF bio-augmentation rhizosphere soils was found to be 46.2%, 65.4%, 67.5% for W+RBF, C+RBF, S+RBF rhizosphere soils respectively. RBF supply impacted on the microbial community diversity (phospholipid fatty acids, PLFA) and the activity of soil enzymes, such as dehydrogenase (DH), alkaline phosphatase (AP) and urease (UR). There were significant difference among the soil only containing crude oil (CK), W, C and S rhizosphere soils and RBF bio-augmentation soils. Moreover, the changes were significantly distinct depended on crops species. It was concluded that the RBF is a valuable material for improving effect of remediation of TPH polluted soils.

  4. The Extract of Rhodobacter sphaeroides Inhibits Melanogenesis through the MEK/ERK Signaling Pathway

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    Chen-Hsun Liu

    2013-06-01

    Full Text Available Reducing hyperpigmentation has been a big issue for years. Even though pigmentation is a normal mechanism protecting skin from UV-causing DNA damage and oxidative stress, it is still an aesthetic problem for many people. Bacteria can produce some compounds in response to their environment. These compounds are widely used in cosmetic and pharmaceutical applications. Some probiotics have immunomodulatory activities and modulate the symptoms of several diseases. Previously, we found that the extracts of Rhodobacter sphaeroides (Lycogen™ inhibited nitric oxide production and inducible nitric-oxide synthase expression in activated macrophages. In this study, we sought to investigate an anti-melanogenic signaling pathway in α-melanocyte stimulating hormone (α-MSH-treated B16F10 melanoma cells and zebrafish. Treatment with Lycogen™ inhibited the cellular melanin contents and expression of melanogenesis-related protein, including microphthalmia-associated transcription factor (MITF and tyrosinase in B16F10 cells. Moreover, Lycogen™ reduced phosphorylation of MEK/ERK without affecting phosphorylation of p38. Meanwhile, Lycogen™ decreased zebrafish melanin expression in a dose-dependent manner. These findings establish Lycogen™ as a new target in melanogenesis and suggest a mechanism of action through the ERK signaling pathway. Our results suggested that Lycogen™ may have potential cosmetic usage in the future.

  5. Redox potential tuning through differential quinone binding in the photosynthetic reaction center of Rhodobacter sphaeroides.

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    Vermaas, Josh V; Taguchi, Alexander T; Dikanov, Sergei A; Wraight, Colin A; Tajkhorshid, Emad

    2015-03-31

    Ubiquinone forms an integral part of the electron transport chain in cellular respiration and photosynthesis across a vast number of organisms. Prior experimental results have shown that the photosynthetic reaction center (RC) from Rhodobacter sphaeroides is only fully functional with a limited set of methoxy-bearing quinones, suggesting that specific interactions with this substituent are required to drive electron transport and the formation of quinol. The nature of these interactions has yet to be determined. Through parameterization of a CHARMM-compatible quinone force field and subsequent molecular dynamics simulations of the quinone-bound RC, we have investigated and characterized the interactions of the protein with the quinones in the Q(A) and Q(B) sites using both equilibrium simulation and thermodynamic integration. In particular, we identify a specific interaction between the 2-methoxy group of ubiquinone in the Q(B) site and the amide nitrogen of GlyL225 that we implicate in locking the orientation of the 2-methoxy group, thereby tuning the redox potential difference between the quinones occupying the Q(A) and Q(B) sites. Disruption of this interaction leads to weaker binding in a ubiquinone analogue that lacks a 2-methoxy group, a finding supported by reverse electron transfer electron paramagnetic resonance experiments of the Q(A)⁻Q(B)⁻ biradical and competitive binding assays.

  6. Hydrogen production by Rhodobacter sphaeroides O.U.001 in a flat plate solar bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Eroglu, Inci; Tabanoglu, Altan; Eroglu, Ela [Department of Chemical Engineering, Middle East Technical University, 06531 Ankara (Turkey); Guenduez, Ufuk; Yuecel, Meral [Department of Biology, Middle East Technical University, 06531 Ankara (Turkey)

    2008-01-15

    Rhodobacter sphaeroides O.U.001 can produce hydrogen under anaerobic conditions and illumination. The objective of this study was to investigate the performance of an 8 l flat plate solar bioreactor operating in outdoor conditions. Different organic acids were used as carbon sources (malate, lactate and acetate) and olive mill waste water was used as a sole substrate source. The consumption and the production of the organic acids were determined by HPLC. The accumulation of by-products, such as poly-{beta}-hydroxybutyrate (PHB) and carotenoid, throughout the course of hydrogen production was determined. The hydrogen production rate was highest (0.01 l/l/h) when malate was the carbon source. Formate was observed as the fermentation end product. Acetate resulted in low hydrogen gas production and high PHB accumulation. When acetate was used as the carbon source, butyrate was produced as a result of fermentation. Promising amounts of PHB and caretenoid were accumulated during hydrogen production from diluted olive mill wastewater. (author)

  7. Variation in supramolecular organisation of the photosynthetic membrane of Rhodobacter sphaeroides induced by alteration of PufX.

    Science.gov (United States)

    Sznee, Kinga; Crouch, Lucy I; Jones, Michael R; Dekker, Jan P; Frese, Raoul N

    2014-02-01

    In purple bacteria of the genus Rhodobacter (Rba.), an LH1 antenna complex surrounds the photochemical reaction centre (RC) with a PufX protein preventing the LH1 complex from completely encircling the RC. In membranes of Rba. sphaeroides, RC-LH1 complexes associate as dimers which in turn assemble into longer range ordered arrays. The present work uses linear dichroism (LD) and dark-minus-light difference LD (ΔLD) to probe the organisation of genetically altered RC-LH1 complexes in intact membranes. The data support previous proposals that Rba. capsulatus, and Rba. sphaeroides heterologously expressing the PufX protein from Rba. capsulatus, produce monomeric core complexes in membranes that lack long-range order. Similarly, Rba. sphaeroides with a point mutation in the Gly 51 residue of PufX, which is located on the membrane-periplasm interface, assembles mainly non-ordered RC-LH1 complexes that are most likely monomeric. All the Rba. sphaeroides membranes in their ΔLD spectra exhibited a spectral fingerprint of small degree of organisation implying the possibility of ordering influence of LH1, and leading to an important conclusion that PufX itself has no influence on ordering RC-LH1 complexes, as long-range order appears to be induced only through its role of configuring RC-LH1 complexes into dimers.

  8. Multi-PAS domain-mediated protein oligomerization of PpsR from Rhodobacter sphaeroides

    Energy Technology Data Exchange (ETDEWEB)

    Heintz, Udo; Meinhart, Anton; Winkler, Andreas, E-mail: andreas.winkler@mpimf-heidelberg.mpg.de [Max Planck Institute for Medical Research, Heidelberg (Germany)

    2014-03-01

    Crystal structures of two truncated variants of the transcription factor PpsR from R. sphaeroides are presented that enabled the phasing of a triple PAS domain construct. Together, these structures reveal the importance of α-helical PAS extensions for multi-PAS domain-mediated protein oligomerization and function. Per–ARNT–Sim (PAS) domains are essential modules of many multi-domain signalling proteins that mediate protein interaction and/or sense environmental stimuli. Frequently, multiple PAS domains are present within single polypeptide chains, where their interplay is required for protein function. Although many isolated PAS domain structures have been reported over the last decades, only a few structures of multi-PAS proteins are known. Therefore, the molecular mechanism of multi-PAS domain-mediated protein oligomerization and function is poorly understood. The transcription factor PpsR from Rhodobacter sphaeroides is such a multi-PAS domain protein that, in addition to its three PAS domains, contains a glutamine-rich linker and a C-terminal helix–turn–helix DNA-binding motif. Here, crystal structures of two N-terminally and C-terminally truncated PpsR variants that comprise a single (PpsR{sub Q-PAS1}) and two (PpsR{sub N-Q-PAS1}) PAS domains, respectively, are presented and the multi-step strategy required for the phasing of a triple PAS domain construct (PpsR{sub ΔHTH}) is illustrated. While parts of the biologically relevant dimerization interface can already be observed in the two shorter constructs, the PpsR{sub ΔHTH} structure reveals how three PAS domains enable the formation of multiple oligomeric states (dimer, tetramer and octamer), highlighting that not only the PAS cores but also their α-helical extensions are essential for protein oligomerization. The results demonstrate that the long helical glutamine-rich linker of PpsR results from a direct fusion of the N-cap of the PAS1 domain with the C-terminal extension of the N-domain that

  9. Multi-PAS domain-mediated protein oligomerization of PpsR from Rhodobacter sphaeroides.

    Science.gov (United States)

    Heintz, Udo; Meinhart, Anton; Winkler, Andreas

    2014-03-01

    Per-ARNT-Sim (PAS) domains are essential modules of many multi-domain signalling proteins that mediate protein interaction and/or sense environmental stimuli. Frequently, multiple PAS domains are present within single polypeptide chains, where their interplay is required for protein function. Although many isolated PAS domain structures have been reported over the last decades, only a few structures of multi-PAS proteins are known. Therefore, the molecular mechanism of multi-PAS domain-mediated protein oligomerization and function is poorly understood. The transcription factor PpsR from Rhodobacter sphaeroides is such a multi-PAS domain protein that, in addition to its three PAS domains, contains a glutamine-rich linker and a C-terminal helix-turn-helix DNA-binding motif. Here, crystal structures of two N-terminally and C-terminally truncated PpsR variants that comprise a single (PpsRQ-PAS1) and two (PpsRN-Q-PAS1) PAS domains, respectively, are presented and the multi-step strategy required for the phasing of a triple PAS domain construct (PpsRΔHTH) is illustrated. While parts of the biologically relevant dimerization interface can already be observed in the two shorter constructs, the PpsRΔHTH structure reveals how three PAS domains enable the formation of multiple oligomeric states (dimer, tetramer and octamer), highlighting that not only the PAS cores but also their α-helical extensions are essential for protein oligomerization. The results demonstrate that the long helical glutamine-rich linker of PpsR results from a direct fusion of the N-cap of the PAS1 domain with the C-terminal extension of the N-domain that plays an important role in signal transduction.

  10. Regulation of Gene Expression by PrrA in Rhodobacter sphaeroides 2.4.1: Role of Polyamines and DNA Topology▿

    Science.gov (United States)

    Eraso, Jesus M.; Kaplan, Samuel

    2009-01-01

    In the present study, we show in vitro binding of PrrA, a global regulator in Rhodobacter sphaeroides 2.4.1, to the PrrA site 2, within the RSP3361 locus. Specific binding, as shown by competition experiments, requires the phosphorylation of PrrA. The binding affinity of PrrA for site 2 was found to increase 4- to 10-fold when spermidine was added to the binding reaction. The presence of extracellular concentrations of spermidine in growing cultures of R. sphaeroides gave rise to a twofold increase in the expression of the photosynthesis genes pucB and pufB, as well as the RSP3361 gene, under aerobic growth conditions, as shown by the use of lacZ transcriptional fusions, and led to the production of light-harvesting spectral complexes. In addition, we show that negative supercoiling positively regulates the expression of the RSP3361 gene, as well as pucB. We show the importance of supercoiling through an evaluation of the regulation of gene expression in situ by supercoiling, in the case of the former gene, as well as using the DNA gyrase inhibitor novobiocin. We propose that polyamines and DNA supercoiling act synergistically to regulate expression of the RSP3361 gene, partly by affecting the affinity of PrrA binding to the PrrA site 2 within the RSP3361 gene. PMID:19411327

  11. Regulation of gene expression by PrrA in Rhodobacter sphaeroides 2.4.1: role of polyamines and DNA topology.

    Science.gov (United States)

    Eraso, Jesus M; Kaplan, Samuel

    2009-07-01

    In the present study, we show in vitro binding of PrrA, a global regulator in Rhodobacter sphaeroides 2.4.1, to the PrrA site 2, within the RSP3361 locus. Specific binding, as shown by competition experiments, requires the phosphorylation of PrrA. The binding affinity of PrrA for site 2 was found to increase 4- to 10-fold when spermidine was added to the binding reaction. The presence of extracellular concentrations of spermidine in growing cultures of R. sphaeroides gave rise to a twofold increase in the expression of the photosynthesis genes pucB and pufB, as well as the RSP3361 gene, under aerobic growth conditions, as shown by the use of lacZ transcriptional fusions, and led to the production of light-harvesting spectral complexes. In addition, we show that negative supercoiling positively regulates the expression of the RSP3361 gene, as well as pucB. We show the importance of supercoiling through an evaluation of the regulation of gene expression in situ by supercoiling, in the case of the former gene, as well as using the DNA gyrase inhibitor novobiocin. We propose that polyamines and DNA supercoiling act synergistically to regulate expression of the RSP3361 gene, partly by affecting the affinity of PrrA binding to the PrrA site 2 within the RSP3361 gene.

  12. Quantifying the effects of light intensity on bioproduction and maintenance energy during photosynthetic growth of Rhodobacter sphaeroides.

    Science.gov (United States)

    Imam, Saheed; Fitzgerald, Colin M; Cook, Emily M; Donohue, Timothy J; Noguera, Daniel R

    2015-02-01

    Obtaining a better understanding of the physiology and bioenergetics of photosynthetic microbes is an important step toward optimizing these systems for light energy capture or production of valuable commodities. In this work, we analyzed the effect of light intensity on bioproduction, biomass formation, and maintenance energy during photoheterotrophic growth of Rhodobacter sphaeroides. Using data obtained from steady-state bioreactors operated at varying dilution rates and light intensities, we found that irradiance had a significant impact on biomass yield and composition, with significant changes in photopigment, phospholipid, and biopolymer storage contents. We also observed a linear relationship between incident light intensity and H2 production rate between 3 and 10 W m(-2), with saturation observed at 100 W m(-2). The light conversion efficiency to H2 was also higher at lower light intensities. Photosynthetic maintenance energy requirements were also significantly affected by light intensity, with links to differences in biomass composition and the need to maintain redox homeostasis. Inclusion of the measured condition-dependent biomass and maintenance energy parameters and the measured photon uptake rate into a genome-scale metabolic model for R. sphaeroides (iRsp1140) significantly improved its predictive performance. We discuss how our analyses provide new insights into the light-dependent changes in bioenergetic requirements and physiology during photosynthetic growth of R. sphaeroides and potentially other photosynthetic organisms.

  13. Identification of key residues that confer Rhodobacter sphaeroides LPS activity at horse TLR4/MD-2.

    Directory of Open Access Journals (Sweden)

    Katherine L Irvine

    Full Text Available The molecular determinants underpinning how hexaacylated lipid A and tetraacylated precursor lipid IVa activate Toll-like receptor 4 (TLR4 are well understood, but how activation is induced by other lipid A species is less clear. Species specificity studies have clarified how TLR4/MD-2 recognises different lipid A structures, for example tetraacylated lipid IVa requires direct electrostatic interactions for agonism. In this study, we examine how pentaacylated lipopolysaccharide from Rhodobacter sphaeroides (RSLPS antagonises human TLR4/MD-2 and activates the horse receptor complex using a computational approach and cross-species mutagenesis. At a functional level, we show that RSLPS is a partial agonist at horse TLR4/MD-2 with greater efficacy than lipid IVa. These data suggest the importance of the additional acyl chain in RSLPS signalling. Based on docking analysis, we propose a model for positioning of the RSLPS lipid A moiety (RSLA within the MD-2 cavity at the TLR4 dimer interface, which allows activity at the horse receptor complex. As for lipid IVa, RSLPS agonism requires species-specific contacts with MD-2 and TLR4, but the R2 chain of RSLA protrudes from the MD-2 pocket to contact the TLR4 dimer in the vicinity of proline 442. Our model explains why RSLPS is only partially dependent on horse TLR4 residue R385, unlike lipid IVa. Mutagenesis of proline 442 into a serine residue, as found in human TLR4, uncovers the importance of this site in RSLPS signalling; horse TLR4 R385G/P442S double mutation completely abolishes RSLPS activity without its counterpart, human TLR4 G384R/S441P, being able to restore it. Our data highlight the importance of subtle changes in ligand positioning, and suggest that TLR4 and MD-2 residues that may not participate directly in ligand binding can determine the signalling outcome of a given ligand. This indicates a cooperative binding mechanism within the receptor complex, which is becoming increasingly

  14. Identification of key residues that confer Rhodobacter sphaeroides LPS activity at horse TLR4/MD-2.

    Science.gov (United States)

    Irvine, Katherine L; Gangloff, Monique; Walsh, Catherine M; Spring, David R; Gay, Nicholas J; Bryant, Clare E

    2014-01-01

    The molecular determinants underpinning how hexaacylated lipid A and tetraacylated precursor lipid IVa activate Toll-like receptor 4 (TLR4) are well understood, but how activation is induced by other lipid A species is less clear. Species specificity studies have clarified how TLR4/MD-2 recognises different lipid A structures, for example tetraacylated lipid IVa requires direct electrostatic interactions for agonism. In this study, we examine how pentaacylated lipopolysaccharide from Rhodobacter sphaeroides (RSLPS) antagonises human TLR4/MD-2 and activates the horse receptor complex using a computational approach and cross-species mutagenesis. At a functional level, we show that RSLPS is a partial agonist at horse TLR4/MD-2 with greater efficacy than lipid IVa. These data suggest the importance of the additional acyl chain in RSLPS signalling. Based on docking analysis, we propose a model for positioning of the RSLPS lipid A moiety (RSLA) within the MD-2 cavity at the TLR4 dimer interface, which allows activity at the horse receptor complex. As for lipid IVa, RSLPS agonism requires species-specific contacts with MD-2 and TLR4, but the R2 chain of RSLA protrudes from the MD-2 pocket to contact the TLR4 dimer in the vicinity of proline 442. Our model explains why RSLPS is only partially dependent on horse TLR4 residue R385, unlike lipid IVa. Mutagenesis of proline 442 into a serine residue, as found in human TLR4, uncovers the importance of this site in RSLPS signalling; horse TLR4 R385G/P442S double mutation completely abolishes RSLPS activity without its counterpart, human TLR4 G384R/S441P, being able to restore it. Our data highlight the importance of subtle changes in ligand positioning, and suggest that TLR4 and MD-2 residues that may not participate directly in ligand binding can determine the signalling outcome of a given ligand. This indicates a cooperative binding mechanism within the receptor complex, which is becoming increasingly important in TLR

  15. Biocontrol activity and patulin-removal effects of Bacillus subtilis, Rhodobacter sphaeroides and Agrobacterium tumefaciens against Penicillium expansum.

    Science.gov (United States)

    Wang, Y; Yuan, Y; Liu, B; Zhang, Z; Yue, T

    2016-11-01

    This study was conducted to evaluate the biocontrol potential of Bacillus subtilis CICC 10034, Rhodobacter sphaeroides CGMCC 1.2182 and Agrobacterium tumefaciens CGMCC 1.2554 against patulin (PAT)-producer Penicillium expansum and their ability to remove PAT. Bacillus subtilis effectively inhibited P. expansum both on apples and in in vitro experiments, which reduced the rot diameter on apples by 38% compared with the control. The reduction was followed by those induced by A. tumefaciens (27·63%) and R. sphaeroides (23·67%). None of the cell-free supernatant (CFS) was able to prevent pathogen growth. Three antagonists could suppress PAT production by P. expansum on apples by 98·5, 93·7 and 94·99% after treatment with B. subtilis, R. sphaeroides and A. tumefaciens respectively. In addition, the three strains led to a 0·56-1·47 log CFU g -1 reduction in colony number of P. expansum on apples. Survival of antagonists on apple wounds revealed their tolerance to PAT. Furthermore, both live and autoclaved cells of three strains efficiently adsorbed artificially spiked PAT from medium. The selected antagonists could be applied before harvesting to control apple infection by PAT-producing fungi and also during processing to act as PAT detoxifiers. Since little information related to the capability of R. sphaeroides and A. tumefaciens to inhibit P. expansum is currently available, the results of this study provide some new perspectives to the biocontrol field. © 2016 The Society for Applied Microbiology.

  16. Synergic regulation of redox potential and oxygen uptake to enhance production of coenzyme Q10 in Rhodobacter sphaeroides.

    Science.gov (United States)

    Zhu, Yongqiang; Ye, Lidan; Chen, Zhaofeng; Hu, Weijiang; Shi, Yanghui; Chen, Jianbo; Wang, Chenfei; Li, Yong; Li, Weifeng; Yu, Hongwei

    2017-06-01

    The physiological role of Coenzyme Q10 (CoQ10) as an electron carrier suggests its association with redox potential. Overexpression of glyceraldehyde-3-phosphate dehydrogenase type I (gapA-1) in Rhodobacter sphaeroides elevated the NADH/NAD+ ratio and meanwhile enhanced the CoQ10 content by 58%, but at the sacrifice of biomass. On the other hand, Vitreoscilla hemoglobin was heterologously expressed to enhance the oxygen uptake ability of the cells, leading to 127% improvement of biomass. Subsequent coexpression of gapA-1 and vgb resulted in a CoQ10 titer of 83.24mg/L, representing 71% improvement as compared to the control strain RspMCS. When gapA-1 and vgb genes were co-expressed in a previously created strain RspMQd [1], 163.5mg/L of CoQ10 was produced. Finally, 600mg/L of CoQ10 production was achieved in fed-batch fermentation. These results demonstrated the synergic effect of redox potential regulation and oxygen uptake improvement on enhancing CoQ10 production in R. sphaeroides. Copyright © 2017. Published by Elsevier Inc.

  17. Biohydrogen and polyhydroxyalkanoate co-production by Enterobacter aerogenes and Rhodobacter sphaeroides from Calophyllum inophyllum oil cake.

    Science.gov (United States)

    Arumugam, A; Sandhya, M; Ponnusami, V

    2014-07-01

    The feasibility of coupled biohydrogen and polyhydroxyalkanoate production by Enterobacter aerogenes and Rhodobacter sphaeroides using Calophyllum inophyllum oil cake was studied under dark and photo fermentation conditions. The utilization of a non-edible acidic oil cake (C. inophyllum), and exploitation of a modified minimal salt media led to reduction in the cost of media. Cost of fermentation is reduced by implementation of alternate dark-photo fermentative periods and through the use of a co-culture consisting of a dark fermentative (E. aerogenes) and a photo fermentative (R. sphaeroides) bacterium. The biohydrogen and polyhydroxyalkanoate produced were 7.95 L H2/L media and 10.73 g/L media, respectively, under alternate dark and photo fermentation and were 3.23 L H2/L media and 5.6g/L media, respectively under complete dark fermentation. The characteristics of the oil cake and alternate dark (16 h) and photo (8h) fermentative conditions were found to be supportive in producing high biohydrogen and polyhydroxyalkanoate (PHA) yield. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Reusing colored industrial wastewaters in a photofermentation for enhancing biohydrogen production by using ultrasound stimulated Rhodobacter sphaeroides.

    Science.gov (United States)

    Budiman, Pretty Mori; Wu, Ta Yeong; Ramanan, Ramakrishnan Nagasundara; Md Jahim, Jamaliah

    2017-07-01

    One-time ultrasonication pre-treatment of Rhodobacter sphaeroides was evaluated for improving biohydrogen production via photofermentation. Batch experiments were performed by varying ultrasonication amplitude (15, 30, and 45%) and duration (5, 10, and 15 min) using combined effluents from palm oil as well as pulp and paper mill as a single substrate. Experimental data showed that ultrasonication at amplitude 30% for 10 min (256.33 J/mL) achieved the highest biohydrogen yield of 9.982 mL H2/mLmedium with 5.125% of light efficiency. A maximum CODtotal removal of 44.7% was also obtained. However, when higher ultrasonication energy inputs (>256.33 J/mL) were transmitted to the cells, biohydrogen production did not improve further. In fact, 20.6% decrease of biohydrogen yield (as compared to the highest biohydrogen yield) was observed using the most intense ultrasonicated inoculum (472.59 J/mL). Field emission scanning electron microscope images revealed the occurrence of cell damages and biomass losses if ultrasonication at 472.59 J/mL was used. The present results suggested that moderate ultrasonication pre-treatment was an effective technique to improve biohydrogen production performances of R. sphaeroides.

  19. Mutagenic analysis of Cox11 of Rhodobacter sphaeroides: Insights into the assembly of CuB of cytochrome c oxidase

    Science.gov (United States)

    Thompson, Audie K.; Smith, Daniel; Gray, Jimmy; Carr, Heather S.; Liu, Aimin; Winge, Dennis R.; Hosler, Jonathan P.

    2010-01-01

    The Cu(I) chaperone Cox11 is required for the insertion of CuB into cytochrome c oxidase (CcO) of mitochondria and many bacteria, including Rhodobacter sphaeroides. Exploration of the copper binding stoichiometry of R. sphaeroides Cox11 led to the finding that an apparent tetramer of both mitochondrial and bacterial Cox11 binds more copper than the sum of the dimers, providing another example of the flexibility of copper binding by Cu(I)-S clusters. Site-directed mutagenesis has been used to identify components of Cox11 that are not required for copper binding but are absolutely required for the assembly of CuB, including conserved Cys-35 and Lys-123. In contrast to earlier proposals, Cys-35 is not required for dimerization of Cox11 or for copper binding. These findings, plus the location of Cys-35 at the C terminus of the predicted transmembrane helix and thereby close to the surface of the membrane, allows a proposal that Cys-35 is involved in the transfer of copper from the Cu(I) cluster of Cox11 to the CuB ligands His-333/334 during the folding of CcO subunit I. Lys-123 is located near the Cu(I) cluster of Cox11, in an area otherwise devoid of charged residues. From the analysis of several Cox11 mutants, including K123E, L and R, we conclude that a previous proposal that Lys-123 provides charge balance for the stabilization of the Cu(I) cluster is unlikely to account for its absolute requirement for Cox11 function. Rather, consideration of the properties of Lys-123 and the apparent specificity of Cox11 suggests that Lys-123 plays a role in the interaction of Cox11 with its target. PMID:20524628

  20. Susceptibility of Rhodobacter sphaeroides to beta-lactam antibiotics: isolation and characterization of a periplasmic beta-lactamase (cephalosporinase).

    Science.gov (United States)

    Baumann, M; Simon, H; Schneider, K H; Danneel, H J; Küster, U; Giffhorn, F

    1989-01-01

    Thirteen strains of the gram-negative, facultative phototrophic bacterium Rhodobacter sphaeroides were examined fro susceptibility to beta-lactam antibiotics. All strains were sensitive to the semisynthetic penicillins ampicillin, carbenicillin, oxacillin, cloxacillin, and methicillin, but 10 of the 13 strains were resistant to penicillin G, as well as a number of cephalosporins, such as cephalothin, cephapirin, and cephalosporin C. A beta-lactamase (EC 3.5.2.6) with strong cephalosporinase activity was detected in all of the resistant strains of R. sphaeroides. With strain Y-1 as a model, it was shown that the beta-lactamase was inducible by penicillin G, cephalosporin C, cephalothin, and to some minor extent, cephapirin. The beta-lactamase was located in the periplasmic space, from which it could be extracted by osmotic shock disruption. By using this fraction, the beta-lactamase was purified 34-fold to homogeneity by steps involving batch adsorption to and elution from DEAE-Sephadex A50, chromatography on Q-Sepharose, and preparative polyacrylamide gel electrophoresis. The molecular masses of the native and denatured enzymes were determined to be 38.5 kilodaltons by gel filtration and 40.5 kilodaltons by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, respectively, indicating a monomeric structure. The isoelectric point was estimated to be at pH 4.3. In Tris hydrochloride buffer, optimum enzyme activity was measured at pH 8.5. The beta-lactamase showed high activity in the presence of the substrates cephalothin, cephapirin, cephalosporin C, and penicillin G, for which the apparent Km values were 144, 100, 65, and 110 microM, respectively. Cephalexin, cepharidine, and cephaloridine were poor substrates. The beta-lactamase was strongly inhibited by cloxacillin and oxacillin but only slightly inhibited by phenylmethylsulfonyl fluoride or thiol reagents such as iodoacetate and p-chloromercuribenzoate.

  1. Physiological Roles for Two Periplasmic Nitrate Reductases in Rhodobacter sphaeroides 2.4.3 (ATCC 17025)▿

    Science.gov (United States)

    Hartsock, Angela; Shapleigh, James P.

    2011-01-01

    The metabolically versatile purple bacterium Rhodobacter sphaeroides 2.4.3 is a denitrifier whose genome contains two periplasmic nitrate reductase-encoding gene clusters. This work demonstrates nonredundant physiological roles for these two enzymes. One cluster is expressed aerobically and repressed under low oxygen while the second is maximally expressed under low oxygen. Insertional inactivation of the aerobically expressed nitrate reductase eliminated aerobic nitrate reduction, but cells of this strain could still respire nitrate anaerobically. In contrast, when the anaerobic nitrate reductase was absent, aerobic nitrate reduction was detectable, but anaerobic nitrate reduction was impaired. The aerobic nitrate reductase was expressed but not utilized in liquid culture but was utilized during growth on solid medium. Growth on a variety of carbon sources, with the exception of malate, the most oxidized substrate used, resulted in nitrite production on solid medium. This is consistent with a role for the aerobic nitrate reductase in redox homeostasis. These results show that one of the nitrate reductases is specific for respiration and denitrification while the other likely plays a role in redox homeostasis during aerobic growth. PMID:21949073

  2. Azoreductase from Rhodobacter sphaeroides AS1.1737 is a flavodoxin that also functions as nitroreductase and flavin mononucleotide reductase.

    Science.gov (United States)

    Liu, Guangfei; Zhou, Jiti; Lv, Hong; Xiang, Xuemin; Wang, Jing; Zhou, Mi; Qv, Yuanyuan

    2007-10-01

    Previously reported azoreductase (AZR) from Rhodobacter sphaeroides AS1.1737 was shown to be a flavodoxin possessing nitroreductase and flavin mononucleotide (FMN) reductase activities. The structure model of AZR constructed with SWISS-MODEL displayed a flavodoxin-like fold with a three-layer alpha/beta/alpha structure. With nitrofurazone as substrate, the optimal pH value and temperature were 7.0 and 50 degrees C, respectively. AZR could reduce a number of nitroaromatic compounds including 2,4-dinitrotoluene, 2,6-dinitrotoluene, 3,5-dinitroaniline, and 2,4,6-trinitrotoluene (TNT). TNT resulted to be the most efficient nitro substrate and was reduced to hydroxylamino-dinitrotoluene. Both NADH and NADPH could serve as electron donors of AZR, where the latter was preferred. Externally added FMN was also reduced by AZR via ping-pong mechanism and was a competitive inhibitor of NADPH, methyl red, and nitrofurazone. AZR with broad substrate specificity is a member of a new nitro/FMN reductase family demonstrating potential application in bioremediation.

  3. Augmenting light coverage for photosynthesis through YFP-enhanced charge separation at the Rhodobacter sphaeroides reaction centre

    Science.gov (United States)

    Grayson, Katie J.; Faries, Kaitlyn M.; Huang, Xia; Qian, Pu; Dilbeck, Preston; Martin, Elizabeth C.; Hitchcock, Andrew; Vasilev, Cvetelin; Yuen, Jonathan M.; Niedzwiedzki, Dariusz M.; Leggett, Graham J.; Holten, Dewey; Kirmaier, Christine; Neil Hunter, C.

    2017-01-01

    Photosynthesis uses a limited range of the solar spectrum, so enhancing spectral coverage could improve the efficiency of light capture. Here, we show that a hybrid reaction centre (RC)/yellow fluorescent protein (YFP) complex accelerates photosynthetic growth in the bacterium Rhodobacter sphaeroides. The structure of the RC/YFP-light-harvesting 1 (LH1) complex shows the position of YFP attachment to the RC-H subunit, on the cytoplasmic side of the RC complex. Fluorescence lifetime microscopy of whole cells and ultrafast transient absorption spectroscopy of purified RC/YFP complexes show that the YFP-RC intermolecular distance and spectral overlap between the emission of YFP and the visible-region (QX) absorption bands of the RC allow energy transfer via a Förster mechanism, with an efficiency of 40+/-10%. This proof-of-principle study demonstrates the feasibility of increasing spectral coverage for harvesting light using non-native genetically-encoded light-absorbers, thereby augmenting energy transfer and trapping in photosynthesis.

  4. Concomitant biohydrogen and poly-β-hydroxybutyrate production from dark fermentation effluents by adapted Rhodobacter sphaeroides and mixed photofermentative cultures.

    Science.gov (United States)

    Ghimire, Anish; Valentino, Serena; Frunzo, Luigi; Pirozzi, Francesco; Lens, Piet N L; Esposito, Giovanni

    2016-10-01

    This work aimed at investigating concomitant production of biohydrogen and poly-β-hydroxybutyrate (PHB) by photofermentation (PF) using dark fermentation effluents (DFE). An adapted culture of Rhodobacter sphaeroides AV1b (pH 6.5, 24±2°C) achieved H2 and PHB yields of 256 (±2) NmLH2/g Chemical Oxygen Demand (COD) and 273.8mgPHB/gCOD (32.5±3% of the dry cells weight (DCW)), respectively. When a diluted (1:2) DFE medium was applied to the adapted pure and mixed photofermentative culture, the respective H2 yields were 164.0 (±12) and 71.3 (±6) NmLH2/gCOD and the PHB yields were 212.1 (±105.2) and 50.7 (±2.7) mgPHB/gCOD added, corresponding to 24 (±0.7) and 6.3 (±0) % DCW, respectively. The concomitant H2 and PHB production from the PF process gave a good DFE post treatment achieving up to 80% COD removal from the initial DFE. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Whole-genome shotgun optical mapping of Rhodobacter sphaeroides strain 2.4. 1 and its use for whole-genome shotgun sequence assembly

    Energy Technology Data Exchange (ETDEWEB)

    Shou, S. [Univ. Wisc.-Madison; Kvikstad, E. [Univ. Wisc.-Madison; Kile, A. [Univ. Wisc.-Madison; Severin, J. [Whole-genome shotgun optical mapping of Rhodobacter sphaeroides strain 2.4. 1 and its use for whole-genome shotgun sequence assembly; Forrest, D. [Univ. Wisc.-Madison; Runnheim, R. [Univ. Wisc.-Madison; Churas, C. [Univ. Wisc.-Madison; Hickman, J. W. [Univ. Wisc.-Madison; Mackenzie, C. [University of Texas–Houston Medical School; Choudhary, M. [University of Texas–Houston Medical School; Donohue, T. [Univ. Wisc.-Madison; Kaplan, S. [University of Texas–Houston Medical School; Schwartz, D. C. [Univ. Wisc.-Madison

    2003-09-01

    Rhodobacter sphaeroides 2.4.1 is a facultative photoheterotrophic bacterium with tremendous metabolic diversity, which has significantly contributed to our understanding of the molecular genetics of photosynthesis, photoheterotrophy, nitrogen fixation, hydrogen metabolism, carbon dioxide fixation, taxis, and tetrapyrrole biosynthesis. To further understand this remarkable bacterium, and to accelerate an ongoing sequencing project, two whole-genome restriction maps (EcoRI and HindIII) of R. sphaeroides strain 2.4.1 were constructed using shotgun optical mapping. The approach directly mapped genomic DNA by the random mapping of single molecules. The two maps were used to facilitate sequence assembly by providing an optical scaffold for high-resolution alignment and verification of sequence contigs. Our results show that such maps facilitated the closure of sequence gaps by the early detection of nascent sequence contigs during the course of the whole-genome shotgun sequencing process.

  6. The Flagellar Switch Genes fliM and fliN of Rhodobacter sphaeroides Are Contained in a Large Flagellar Gene Cluster

    OpenAIRE

    García, Norma; Campos, Andrés; Osorio, Aurora; Poggio, Sebastian; González-Pedrajo, Bertha; Camarena, Laura; Dreyfus, Georges

    1998-01-01

    In this work, the genes that encode the FliM and FliN proteins of Rhodobacter sphaeroides were characterized. These genes are part of a large flagellar gene cluster in which six additional open reading frames encoding products homologous to FliL, FliO, FliP, FliQ, FliR, and FlhB proteins from other bacteria were identified. The inactivation of the fliM gene gave a nonflagellate phenotype (Fla−), suggesting that FliM is required for flagellar assembly. Complementation analysis of this fliM mut...

  7. A synthetic biological secondary metabolite, Lycogen™, produced and extracted from Rhodobacter sphaeroides WL-APD911 in an optimizatioal scale-up strategy

    Directory of Open Access Journals (Sweden)

    Cheng-Chin Wang

    2017-12-01

    Full Text Available The optimization of fermentation medium is important for synthetic biological secondary metabolite productions. The effect of rotation speed, inoculum amount, and medium supplements on the cell growth and Lycogen™ secretion of photobacterium Rhodobacter sphaeroides WL-APD911 was evaluated. The results reveal that a higher rotational speed exhibit a higher cell density, and the increasing in the amount of inoculum amount show a slight augment on the growth of R. sphaeroides WL-APD911.In the case of nitrogen sources adding, Lycogen™ production was achieved with a 0.5 mM l-lysine supplementation. Moreover, the attention of Tween 80 presented a tremendous increase in the secondary metabolite. Response surface methodology (RSM exhibited the optimization of medium supplements for Lycogen™ invention is accomplished at molasses concentration of 10 g/L, yeast extract concentration of 40 g/L, 0.3% Tween 80 and NaCl concentration of 5 g/L, respectively. Further, the batch fermentation is carried out in both 5 L and 20 L fermentors to study the scale-up process factors to be adopted. At a 20 L fermentor, Lycogen™ yields under the optimal culture condition are over 2 times than in the shake flask. The present results provide the Lycogen™ optimal culture mediums, scale-up procedures and efficient extractions from R. sphaeroides WL-APD911. Keywords: Rhodobacter sphaeroides WL-APD911, Lycogen™, Response surface methodology (RSM, Ferementation

  8. Biological Synthesis of Size-Controlled Cadmium Sulfide Nanoparticles Using ImmobilizedRhodobacter sphaeroides

    Directory of Open Access Journals (Sweden)

    Zhang Zhaoming

    2009-01-01

    Full Text Available Abstract Size-controlled cadmium sulfide nanoparticles were successfully synthesized by immobilizedRhodobacter sphaeroidesin the study. The dynamic process that Cd2+was transported from solution into cell by livingR. sphaeroideswas characterized by transmission electron microscopy (TEM. Culture time, as an important physiological parameter forR. sphaeroidesgrowth, could significantly control the size of cadmium sulfide nanoparticles. TEM demonstrated that the average sizes of spherical cadmium sulfide nanoparticles were 2.3 ± 0.15, 6.8 ± 0.22, and 36.8 ± 0.25 nm at culture times of 36, 42, and 48 h, respectively. Also, the UV–vis and photoluminescence spectral analysis of cadmium sulfide nanoparticles were performed.

  9. Enhanced production of coenzyme Q10 by self-regulating the engineered MEP pathway in Rhodobacter sphaeroides.

    Science.gov (United States)

    Lu, Wenqiang; Ye, Lidan; Xu, Haoming; Xie, Wenping; Gu, Jiali; Yu, Hongwei

    2014-04-01

    Fine-tuning the expression level of an engineered pathway is crucial for the metabolic engineering of a host toward a desired phenotype. However, most engineered hosts suffer from nonfunctional protein expression, metabolic imbalance, cellular burden or toxicity from intermediates when an engineered pathway is first introduced, which can decrease production of the desired product. To circumvent these obstacles, we developed a self-regulation system utilizing the trc/tac promoter, LacI(q) protein and ribosomal binding sites (RBS). With the purpose of improving coenzyme Q10 (CoQ10 ) production by increasing the decaprenyl diphosphate supplement, enzymes DXS, DXR, IDI, and IspD were constitutively overexpressed under the control of the trc promoter in Rhodobacter sphaeroides. Then, a self-regulation system combining a set of RBSs for adjusting the expression of the LacI(q) protein was applied to tune the expression of the four genes, resulting in improved CoQ10 production. Finally, another copy of the tac promoter with the UbiG gene (involved in the ubiquinone pathway of CoQ10 biosynthesis) was introduced into the engineered pathway. By optimizing the expression level of both the upstream and downstream pathway, CoQ10 production in the mutants was improved up to 93.34 mg/L (7.16 mg/g DCW), about twofold of the wild-type (48.25 mg/L, 3.24 mg/g DCW). © 2013 Wiley Periodicals, Inc.

  10. Cardiolipin Deficiency in Rhodobacter sphaeroides Alters the Lipid Profile of Membranes and of Crystallized Cytochrome Oxidase, but Structure and Function Are Maintained

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xi; Tamot, Banita; Hiser, Carrie; Reid, Gavin E.; Benning, Christoph; Ferguson-Miller, Shelagh (MSU)

    2012-05-08

    Many recent studies highlight the importance of lipids in membrane proteins, including in the formation of well-ordered crystals. To examine the effect of changes in one lipid, cardiolipin, on the lipid profile and the production, function, and crystallization of an intrinsic membrane protein, cytochrome c oxidase, we mutated the cardiolipin synthase (cls) gene of Rhodobacter sphaeroides, causing a >90% reduction in cardiolipin content in vivo and selective changes in the abundances of other lipids. Under these conditions, a fully native cytochrome c oxidase (CcO) was produced, as indicated by its activity, spectral properties, and crystal characteristics. Analysis by MALDI tandem mass spectrometry (MS/MS) revealed that the cardiolipin level in CcO crystals, as in the membranes, was greatly decreased. Lipid species present in the crystals were directly analyzed for the first time using MS/MS, documenting their identities and fatty acid chain composition. The fatty acid content of cardiolipin in R. sphaeroides CcO (predominantly 18:1) differs from that in mammalian CcO (18:2). In contrast to the cardiolipin dependence of mammalian CcO activity, major depletion of cardiolipin in R. sphaeroides did not impact any aspect of CcO structure or behavior, suggesting a greater tolerance of interchange of cardiolipin with other lipids in this bacterial system.

  11. Effect of light intensity and various organic acids on the growth of Rhodobacter sphaeroides LHII-deficient mutant in a turbidostat culture.

    Science.gov (United States)

    Eltsova, Zinaida; Bolshakov, Maxim; Tsygankov, Anatoly

    2016-12-01

    The composition of photosynthetic apparatus of Rhodobacter sphaeroides wild strain 2.4.1 and its LHII-deficient mutant DBCΩ was compared. The absence of LHII in the mutant was confirmed by comparison of chromatophores spectra and by the absence of electrophoretic band corresponding to LHII complex. Continuous turbidostat cultures of wild strain and its LHII-deficient mutant were compared in response to different light intensities. Cultures were grown using lactate, mixture of lactate and acetate or succinate as carbon source. For comparative analysis, an approximation of experimental data by Monod and Gompertz equations were used. Cultures of DBCΩ had lower growth rates than wild strain when grown on lactate as electron donor and carbon source. Cultures of both strains grown on lactate and acetate or on succinate had similar growth rates. The cultures showed maximum growth rates when grown with succinate. Bacteriochlorophyll a content increased in both strains with decrease of incident light intensity. However, the variation of Bchl a content in wild strain was much more significant. Under light-limiting conditions, bacteriochlorophyll a content in DBCΩ was 4-5 times lower than in the wild strain. Under light-saturating conditions, it was only 1.5-2.5 times lower. Growing with lactate or with lactate and acetate, the mutant switched from light limitation under low light intensities to limitation by organic acids under higher light, whereas the parental strain had similar switch of limiting factor only when growing with lactate and acetate mixture. DBCΩ mutant has higher minimal light intensity enabling growth on any organic acid as a substrate. When growing with lactate or with lactate and acetate, the mutant reached maximum growth rate at lower light intensities than the wild strain. This phenomenon was observed for the first time. Taking into account the concentration of BChl a under light-limiting conditions, the thickness of the suspension capable of

  12. The influence of structural-dynamic organization of RC from purple bacterium rhodobacter sphaeroides on picosecond stages of photoinduced reactions

    Science.gov (United States)

    Paschenko; Gorokhov; Grishanova; Goryacheva; Korvatovsky; Knox; Zakharova; Rubin

    1998-05-27

    Effects of the hydrogen bond network on the rate constants of energy migration (km), charge separation (ke), electron transfer to QA (kQ) and P+I- recombination in RC of Rhodobacter sphaeroides were analysed in control and modified RC preparations at different temperatures. Modification of RC were made by the addition of 40% v/v DMSO. The rate constants km, ke, kQ were evaluated from pump-and-probe measurements of the absorption difference kinetics at 665 nm corresponding to BPhL- formation and subsequent electron transfer to QA. For the investigation of P+I- recombination a primary quinone acceptor was pre-reduced in the dark by adding of 1 mg/ml of dithionite and 1 mM sodium ascorbate. Recombination kinetics were measured at 665 and 870 nm. The numerical analysis of the temperature dependence of ke and kQ was performed on the basis of the model proposed by Kakitani and Kakitani (T. Kakitani and H. Kakitani (1981), Biochim. Biophys. Acta, 635, 498-514). It was found that: (a) in control samples the molecular rate constants km, ke and kQ were about (3.4 ps)-1, (4.5 ps)-1 and (200 ps)-1, respectively; (b) under modification by DMSO these rates decrease up to (5.3 ps)-1, (10.3 ps)-1 and (500 ps)-1, respectively; (c) as the temperature drops from 300 K to 77 K the rate constant km decreases by 1.8 times in control and by 3.2 times in modified samples. In contrast to the observed km changes the increase in ke and kQ values by 2 and more times under cooling was found in control and modified RC; (d) in control preparations with QA acceptor pre-reduced in the dark the lowering of the temperature caused the increase in the time of P+I- recombination from 10 to 20 ns. After DMSO modification the kinetics of charge recombination in RC was biexponential at room temperature with tau=10 ns and tau1=0.8 ns, and at 77 K with tau=20 ns and tau1=0.6 ns, correspondingly. The results obtained reveal that in RC isolated from Rb. sphaeroides the processes of energy migration, charge

  13. Light-harvesting complex 1 stabilizes P+QB- charge separation in reaction centers of Rhodobacter sphaeroides.

    Science.gov (United States)

    Francia, Francesco; Dezi, Manuela; Rebecchi, Alberto; Mallardi, Antonia; Palazzo, Gerardo; Melandri, Bruno Andrea; Venturoli, Giovanni

    2004-11-09

    The kinetics of charge recombination following photoexcitation by a laser pulse have been analyzed in the reaction center-light harvesting complex 1 (RC-LH1) purified from the photosynthetic bacterium Rhodobacter sphaeroides. In RC-LH1 core complexes isolated from photosynthetically grown cells P(+)Q(B)(-) recombines with an average rate constant, k approximately 0.3 s(-1), more than three times smaller than that measured in RC deprived of the LH1 (k approximately 1 s(-1)). A comparable, slowed recombination kinetics is observed in RC-LH1 complexes purified from a pufX-deleted strain. Slowing of the charge recombination kinetics is even more pronounced in RC-LH1 complexes isolated from wild-type semiaerobically grown cells (k approximately 0.2 s(-1)). Since the kinetics of P(+)Q(A)(-) recombination is unaffected by the presence of the antenna, the P(+)Q(B)(-) state appears to be energetically stabilized in core complexes. Determinations of the ubiquinone-10 (UQ(10)) complement associated with the purified RC-LH1 complexes always yield UQ(10)/RC ratios larger than 10. These quinone molecules are functionally coupled to the RC-LH1 complex, as judged from the extent of exogenous cytochrome c(2) rapidly oxidized under continuous light excitation. Analysis of P(+)Q(B)(-) recombination, based on a kinetic model which considers fast quinone equilibrium at the Q(B) binding site, indicates that the slowing down of charge recombination kinetics observed in RC-LH1 complexes cannot be explained solely by a quinone concentration effect and suggests that stabilization of the light-induced charge separation is predominantly due to interaction of the Q(B) site with the LH1 complex. The high UQ(10) complements detected in RC-LH1 core complexes, but not in purified light-harvesting complex 2 and in RC, are proposed to reflect an in vivo heterogeneity in the distribution of the quinone pool within the chromatophore bilayer.

  14. Structural and preliminary molecular dynamics studies of the Rhodobacter sphaeroides reaction center and its mutant form L(M196)H + H(M202)L

    Science.gov (United States)

    Klyashtorny, V. G.; Fufina, T. Yu.; Vasilieva, L. G.; Shuvalov, V. A.; Gabdulkhakov, A. G.

    2014-07-01

    Pigment-protein interactions are responsible for the high efficiency of the light-energy transfer and conversion in photosynthesis. The reaction center (RC) from the purple bacterium Rhodobacter sphaeroides is the most convenient model for studying the mechanisms of primary processes of photosynthesis. Site-directed mutagenesis can be used to study the effect of the protein environment of electron-transfer cofactors on the optical properties, stability, pigment composition, and functional activity of RC. The preliminary analysis of RC was performed by computer simulation of the amino acid substitutions L(M196)H + H(M202)L at the pigment-protein interface and by estimating the stability of the threedimensional structure of the mutant RC by the molecular dynamics method. The doubly mutated reaction center was overexpressed, purified, and crystallized. The three-dimensional structure of this mutant was determined by X-ray crystallography and compared with the molecular dynamics model.

  15. Effect of pH on optimization of photofermentative hydrogen production by co-culture of Rhodobacter sphaeroides-NMBL-02 and Bacillus firmus-NMBL-03.

    Science.gov (United States)

    Pandey, A; Dolly, S; Semwal, D; Pandey, A

    2017-07-31

    Rhodobacter sphaeroides NMBL-02, photosynthetic purple non sulfur (PNS) bacteria and associated Bacillus firmus NMBL-03 were isolated from water sample collected from 15-20 inches beneath the surface of ponds from Northern region of India in modified Sistrom's media (120 ml) containing 3 g/L malate and 1.2 g/L ammonium sulfate. The isolation was done in air tight serum bottles (120 ml) under tungsten bulb (1.8 kLux light intensity) at 30 oC ± 2 oC. The PNS and heterotrophic bacteria associated with the culture was purified by clonal selection method and characterized by 16S rDNA sequencing. The PNS isolate was identified as Rhodobacter sphaeroides NMBL-02 (ID: 1467407, Accession BANKIT: JN256030) and associated heterotroph as Bacillus firmus NMBL-03 (Gene Bank Accession no.: JN 256029). The effect of initial medium pH on optimization of hydrogen production was investigated in batch process. The maximum hydrogen potential and hydrogen production rate was 2310 ± 55 ml/L and 4.75 ml/L culture/h respectively using glutamate (1.7 mmol/L) as nitrogen source and malate (22.38 mmol/L) as carbon source with 76.39% malate conversion efficiency at initial medium pH 5.0. This co-culture has the ability to produce significant amount of hydrogen in the pH range of 5.0 to 10.0 with 76.39% to 35.71% malate conversion respectively.

  16. The effect of different levels of the B800-850 light-harvesting complex on intracytoplasmic membrane development in Rhodobacter sphaeroides

    Science.gov (United States)

    Sturgis; Niedermann

    1996-04-01

    A role for the peripheral (B800-850) light-harvesting complex in vesicularization of the Rhodobacter sphaeroides intracytoplasmic membrane (ICM), suggested from studies in mutant strains lacking one or more of the pigment-protein complexes, was examined further in the wild-type strain NCIB 8253 grown at high ( approximately 1000 W m-2), moderate ( approximately 300 W m-2), and low ( approximately 100 W m-2) light intensities. The resulting ICM vesicles (chromatophores) had B800-850 levels related inversely to irradiance and banded in rate-zone sedimentation at approximately 1.10, 1.09, and 1.07 g ml-1, respectively. Equilibrium centrifugation on iso-osmotic gradients indicated that this distinct sedimentation behavior resulted solely from differences in hydrodynamic radii. These size differences were confirmed by gel-exclusion chromatography and in electron micrographs of thin-sectioned cells. A pulse-chase study of ICM growth following a tenfold reduction in light intensity showed a relatively slow equilibration of membrane proteins during adaptation, and that new protein was incorporated largely into additional ICM formed at the lowered illumination level, giving rise to chromatophores of reduced size and elevated B800-850 content. These results provide further evidence for a model in which the B800-850 complex both drives development of vesicular ICM in Rba. sphaeroides and determines the size of resulting vesicles.

  17. Heterologous expression of glutamyl-tRNA reductase gene in Rhodobacter sphaeroides O.U.001 to enhance 5-aminolevulinic acid production

    Science.gov (United States)

    Kars, Gökhan; Alparslan, Ümmühan

    2014-01-01

    The pathways for synthesis of 5-aminolevulinic acid (5-ALA) use either succinyl-CoA and glycine (C-4 pathway), or glutamate (C-5 pathway). Although Rhodobacter sphaeroides synthesizes 5-ALA through the C-4 pathway, it also has the genes coding for the enzymes of the C-5 pathway, except for glutamyl-tRNA reductase. The glutamyl-tRNA reductase gene was cloned from Rhodospirillum rubrum and expressed in R. sphaeroides; thus, the C-5 pathway was enabled to function upon assembling all the required genes. Consequently, a new and unique bacterial strain producing more 5-ALA was developed. Biohydrogen was also produced in the same bioprocess within a biorefinery approach using sugar beet molasses as substrate. The amount of 5-ALA produced by the modified strain was 25.9 mg/g dry cell weight (DCW), whereas the wild-type strain produced 12.4 mg/g DCW. In addition, the amount of H2 generated by the modified and wild-type cells, respectively, was 0.92 L/L culture and 1.05 L/L culture. PMID:26740781

  18. Occurrence of oleic and 18:1 methyl-branched acyl chains in lipids of Rhodobacter sphaeroides 2.4.1.

    Science.gov (United States)

    Granafei, Sara; Losito, Ilario; Salivo, Simona; Tranchida, Peter Q; Mondello, Luigi; Palmisano, Francesco; Cataldi, Tommaso R I

    2015-07-23

    The fatty acids (FAs) composition of lipids extracted from Rhodobacter sphaeroides 2.4.1 was investigated by gas chromatography-mass spectrometry (GC-MS) analysis of the corresponding FA methyl esters (FAMEs), obtained through trans-esterification of the original lipid species. A GC stationary phase based on a highly polar ionic liquid (IL) was selected, aimed to enhance the separation of isomeric FAMEs with particular emphasis on positional and geometrical isomers of monounsaturated 16:1 and 18:1 fatty acyl chains. The occurrence of 18:1 cis-Δ(9) (oleic) acid, a positional isomer of the well-known and most predominant 18:1 cis-Δ(11) (cis-vaccenic) acid, has been demonstrated here for the first time. Furthermore a methyl branched 18:1 FA was also identified and its structure tentatively assigned as 11-methyl-Δ(12)-octadecenoic acid (most likely as trans isomer). The unprecedented observation about 18:1 cis-Δ(9) FA occurrence in R. sphaeroides 2.4.1 is, even indirectly, supported by a biosynthetic pathway postulated with the aid of the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. The concurrent presence of 16:1 cis-Δ(7) and 18:1 cis-Δ(9) FAs suggested the existence of parallel and/or complementary processes to those invoked for the formation of most common 16:1 cis-Δ(9) and 18:1 cis-Δ(11) FAs. A further route was hypothesized for the trans FAs biosynthesis in wild-type cells of R. sphaeroides. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Investigation of the redox interaction between Mn-bicarbonate complexes and reaction centers from Rhodobacter sphaeroides R-26, Chromatium minutissimum, and Chloroflexus aurantiacus.

    Science.gov (United States)

    Terentyev, V V; Shkuropatov, A Ya; Shkuropatova, V A; Shuvalov, V A; Klimov, V V

    2011-12-01

    The change in the dark reduction rate of photooxidized reaction centers (RC) of type II from three anoxygenic bacteria (Rhodobacter sphaeroides R-26, Chromatium minutissimum, and Chloroflexus aurantiacus) having different redox potentials of the P(+)/P pair and availability of RC for exogenous electron donors was investigated upon the addition of Mn(2+) and HCO(3)(-). It was found that the dark reduction of P(870)(+) from Rb. sphaeroides R-26 is considerably accelerated upon the combined addition of 0.5 mM MnCl(2) and 30-75 mM NaHCO(3) (as a result of formation of "low-potential" complexes [Mn(HCO(3))(2)]), while MnCl(2) and NaHCO(3) added separately had no such effect. The effect is not observed either in RC from Cf. aurantiacus (probably due to the low oxidation potential of the primary electron donor, P(865), which results in thermodynamic difficulties of the redox interaction between P(865)(+) and Mn(2+)) or in RC from Ch. minutissimum (apparently due to the presence of the RC-bound cytochrome preventing the direct interaction between P(870)(+) and Mn(2+)). The absence of acceleration of the dark reduction of P(870)(+) in the RC of Rb. sphaeroides R-26 when Mn(2+) and HCO(3)(-) were replaced by Mg(2+) or Ca(2+) and by formate, oxalate, or acetate, respectively, reveals the specificity of the Mn2+-bicarbonate complexes for the redox interaction with P(+). The results of this work might be considered as experimental evidence for the hypothesis of the participation of Mn(2+) complexes in the evolutionary origin of the inorganic core of the water oxidizing complex of photosystem II. © Pleiades Publishing, Ltd., 2011.

  20. The C-terminus of PufX plays a key role in dimerisation and assembly of the reaction center light-harvesting 1 complex from Rhodobacter sphaeroides.

    Science.gov (United States)

    Qian, Pu; Martin, Elizabeth C; Ng, Irene W; Hunter, C Neil

    2017-09-01

    In bacterial photosynthesis reaction center-light-harvesting 1 (RC-LH1) complexes trap absorbed solar energy by generating a charge separated state. Subsequent electron and proton transfers form a quinol, destined to diffuse to the cytochrome bc1 complex. In bacteria such as Rhodobacter (Rba.) sphaeroides and Rba. capsulatus the PufX polypeptide creates a channel for quinone/quinol traffic across the LH1 complex that surrounds the RC, and it is therefore essential for photosynthetic growth. PufX also plays a key role in dimerization of the RC-LH1-PufX core complex, and the structure of the Rba. sphaeroides complex shows that the PufX C-terminus, particularly the region from X49-X53, likely mediates association of core monomers. To investigate this putative interaction we analysed mutations PufX R49L, PufX R53L, PufX R49/53L and PufX G52L by measuring photosynthetic growth, fractionation of detergent-solubilised membranes, formation of 2-D crystals and electron microscopy. We show that these mutations do not affect assembly of PufX within the core or photosynthetic growth but they do prevent dimerization, consistent with predictions from the RC-LH1-PufX structure. We obtained low resolution structures of monomeric core complexes with and without PufX, using electron microscopy of negatively stained single particles and 3D reconstruction; the monomeric complex with PufX corresponds to one half of the dimer structure whereas LH1 completely encloses the RC if the gene encoding PufX is deleted. On the basis of the insights gained from these mutagenesis and structural analyses we propose a sequence for assembly of the dimeric RC-LH1-PufX complex. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

  1. Properties of hybrid complexes composed of photosynthetic reaction centers from the purple bacterium Rhodobacter sphaeroides and quantum dots in lecithin liposomes.

    Science.gov (United States)

    Zagidullin, V E; Lukashev, E P; Knox, P P; Seifullina, N Kh; Sokolova, O S; Pechnikova, E V; Lokstein, H; Paschenko, V Z

    2014-11-01

    Quantum dots (QDs) can absorb ultraviolet and long-wavelength light energy much more efficiently than natural light-harvesting proteins and transfer the excitation energy to photosynthetic reaction centers (RCs). Inclusion into liposomes of RC membrane pigment-protein complexes combined with QDs as antennae opens new opportunities for using such hybrid systems as a basis for artificial energy-transforming devices that potentially can operate with greater efficiency and stability than devices based only on biological components. RCs from Rhodobacter sphaeroides and QDs with fluorescence maximum at 530 nm (CdSe/ZnS with hydrophilic covering) were embedded in lecithin liposomes by extrusion of a solution of multilayer lipid vesicles through a polycarbonate membrane or by dialysis of lipids and proteins dispersed with excess detergent. The dimensions of the resulting hybrid systems were evaluated using dynamic light scattering and by transmission cryoelectron microscopy. The efficiency of RC and QD interaction within the liposomes was estimated using fluorescence excitation spectra of the photoactive bacteriochlorophyll of the RCs and by measuring the fluorescence decay kinetics of the QDs. The functional activity of the RCs in hybrid complexes was fully maintained, and their stability was even increased.

  2. Effects of the cryptochrome CryB from Rhodobacter sphaeroides on global gene expression in the dark or blue light or in the presence of singlet oxygen.

    Directory of Open Access Journals (Sweden)

    Sebastian Frühwirth

    Full Text Available Several regulators are controlling the formation of the photosynthetic apparatus in the facultatively photosynthetic bacterium Rhodobacter sphaeroides. Among the proteins affecting photosynthesis gene expression is the blue light photoreceptor cryptochrome CryB. This study addresses the effect of CryB on global gene expression. The data reveal that CryB does not only influence photosynthesis gene expression but also genes for the non-photosynthetic energy metabolism like citric acid cycle and oxidative phosphorylation. In addition several genes involved in RNA processing and in transcriptional regulation are affected by a cryB deletion. Although CryB was shown to undergo a photocycle it does not only affect gene expression in response to blue light illumination but also in response to singlet oxygen stress conditions. While there is a large overlap in these responses, some CryB-dependent effects are specific for blue-light or photooxidative stress. In addition to protein-coding genes some genes for sRNAs show CryB-dependent expression. These findings give new insight into the function of bacterial cryptochromes and demonstrate for the first time a function in the oxidative stress response.

  3. Carotenoid to bacteriochlorophyll energy transfer in the RC-LH1-PufX complex from Rhodobacter sphaeroides containing the extended conjugation keto-carotenoid diketospirilloxanthin.

    Science.gov (United States)

    Šlouf, Václav; Keşan, Gürkan; Litvín, Radek; Swainsbury, David J K; Martin, Elizabeth C; Hunter, C Neil; Polívka, Tomáš

    2017-05-20

    RC-LH1-PufX complexes from a genetically modified strain of Rhodobacter sphaeroides that accumulates carotenoids with very long conjugation were studied by ultrafast transient absorption spectroscopy. The complexes predominantly bind the carotenoid diketospirilloxanthin, constituting about 75% of the total carotenoids, which has 13 conjugated C=C bonds, and the conjugation is further extended to two terminal keto groups. Excitation of diketospirilloxanthin in the RC-LH1-PufX complex demonstrates fully functional energy transfer from diketospirilloxanthin to BChl a in the LH1 antenna. As for other purple bacterial LH complexes having carotenoids with long conjugation, the main energy transfer route is via the S2-Qx pathway. However, in contrast to LH2 complexes binding diketospirilloxanthin, in RC-LH1-PufX we observe an additional, minor energy transfer pathway associated with the S1 state of diketospirilloxanthin. By comparing the spectral properties of the S1 state of diketospirilloxanthin in solution, in LH2, and in RC-LH1-PufX, we propose that the carotenoid-binding site in RC-LH1-PufX activates the ICT state of diketospirilloxanthin, resulting in the opening of a minor S1/ICT-mediated energy transfer channel.

  4. Characterisation of the mob locus of Rhodobacter sphaeroides WS8: mobA is the only gene required for molybdopterin guanine dinucleotide synthesis.

    Science.gov (United States)

    Buchanan, G; Kuper, J; Mendel, R R; Schwarz, G; Palmer, T

    2001-07-01

    The mob genes of several bacteria have been implicated in the conversion of molybdopterin to molybdopterin guanine dinucleotide. The mob locus of Rhodobacter sphaeroides WS8 comprises three genes, mobABC. Chromosomal in-frame deletions in each of the mob genes have been constructed. The mobA mutant strain has inactive DMSO reductase and periplasmic nitrate reductase activities (both molybdopterin guanine dinucleotide-requiring enzymes), but the activity of xanthine dehydrogenase, a molybdopterin enzyme, is unaffected. The inability of a mobA mutant to synthesise molybdopterin guanine dinucleotide is confirmed by analysis of cell extracts of the mobA strain for molybdenum cofactor forms following iodine oxidation. Mutations in mobB and mobC are not impaired for molybdoenzyme activities and accumulate wild-type levels of molybdopterin and molybdopterin guanine dinucleotide, indicating they are not compromised in molybdenum cofactor synthesis. In the mobA mutant strain, the inactive DMSO reductase is found in the periplasm, suggesting that molybdenum cofactor insertion is not necessarily a pre-requisite for export.

  5. Primary electron transfer in reaction centers of YM210L and YM210L/HL168L mutants of Rhodobacter sphaeroides.

    Science.gov (United States)

    Yakovlev, A G; Vasilieva, L G; Khmelnitskaya, T I; Shkuropatova, V A; Shkuropatov, A Ya; Shuvalov, V A

    2010-07-01

    The role of tyrosine M210 in charge separation and stabilization of separated charges was studied by analyzing of the femtosecond oscillations in the kinetics of decay of stimulated emission from P* and of a population of the primary charge separated state P(+)B(A)(-) in YM210L and YM210L/HL168L mutant reaction centers (RCs) of Rhodobacter sphaeroides in comparison with those in native Rba. sphaeroides RCs. In the mutant RCs, TyrM210 was replaced by Leu. The HL168L mutation placed the redox potential of the P(+)/P pair 123 mV below that of native RCs, thus creating a theoretical possibility of P(+)B(A)(-) stabilization. Kinetics of P* decay at 940 nm of both mutants show a significant slowing of the primary charge separation reaction in comparison with native RCs. Distinct damped oscillations in these kinetics with main frequency bands in the range of 90-150 cm(-1) reflect mostly nuclear motions inside the dimer P. Formation of a very small absorption band of B(A)(-) at 1020 nm is registered in RCs of both mutants. The formation of the B(A)(-) band is accompanied by damped oscillations with main frequencies from ~10 to ~150 cm(-1). Only a partial stabilization of the P(+)B(A)(-) state is seen in the YM210L/HL168L mutant in the form of a small non-oscillating background of the 1020-nm kinetics. A similar charge stabilization is absent in the YM210L mutant. A model of oscillatory reorientation of the OH-group of TyrM210 in the electric fields of P(+) and B(A)(-) is proposed to explain rapid stabilization of the P(+)B(A)(-) state in native RCs. Small oscillatory components at ~330-380 cm(-1) in the 1020-nm kinetics of native RCs are assumed to reflect this reorientation. We conclude that the absence of TyrM210 probably cannot be compensated by lowering of the P(+)B(A)(-) free energy that is expected for the double YM210L/HL168L mutant. An oscillatory motion of the HOH55 water molecule under the influence of P(+) and B(A)(-) is assumed to be another potential

  6. Agonistic and antagonistic activities of bacterially derived Rhodobacter sphaeroides lipid A: comparison with activities of synthetic material of the proposed structure and analogs.

    Science.gov (United States)

    Rose, J R; Christ, W J; Bristol, J R; Kawata, T; Rossignol, D P

    1995-03-01

    Lipid A from the photosynthetic bacterium Rhodobacter sphaeroides (RSLA) has been previously shown to antagonize many of the effects of endotoxins from more pathogenic gram-negative bacteria. We have reported on the synthesis of the proposed structure of RSLA and determined that bacterially derived RSLA is not identical to its proposed structure (W.J. Christ, P. D. McGuinness, O. Asano, Y. Wang, M. A. Mullarkey, M. Perez, L. D. Hawkins, T. A. Blythe, G. R. Dubuc, and A. L. Robidoux, J. Am. Chem. Soc. 116:3637-3638, 1994). Here we report results of analyzing the antagonistic and agonistic activities of bacterially derived RSLA in comparison with the activities of chemically synthesized material of the proposed structure of RSLA and analogs. Results indicated that all compounds were approximately equally potent at inhibiting endotoxin-induced release of tumor necrosis factor alpha from human monocytes and human whole blood as well as endotoxin-induced generation of nitric oxide in murine macrophages. In addition, all compounds were of equivalent potencies at inhibiting the binding of 125I-labelled lipopolysaccharide derivatized with 2-(p-azido-salicylamido) ethyl-1-3'-dithiopropionate to murine macrophages. Higher concentrations of bacterially derived RSLA (10 to 100 microM) were agonistic in human and murine assays. In gamma interferon-treated murine macrophages, agonism was exhibited at concentrations as low as 100 nM. In contrast, all synthetic materials were either dramatically less agonistic or devoid of agonistic activity when tested at concentrations as high as 100 microM. It is possible either that bacterially derived RSLA contains a small amount of a highly agonistic impurity or that the agonistic activity of RSLA is intrinsic to its molecular structure. In either case, these biological results support our previous report concluding that biologically derived RSLA is not identical to synthetic material of its proposed structure.

  7. Femtosecond stage of electron transfer in reaction centers of the triple mutant SL178K/GM203D/LM214H of Rhodobacter sphaeroides.

    Science.gov (United States)

    Yakovlev, A G; Shkuropatova, T A; Shkuropatova, V A; Shuvalov, V A

    2010-04-01

    Coherent processes in an initial phase of charge transfer in reaction centers (RCs) of the triple mutant S(L178)K/G(M203)D/L(M214)H of Rhodobacter sphaeroides were investigated by difference (light - dark) absorption spectroscopy with 18 fsec time resolution. Electron transfer in the B cofactor branch is activated in this mutant, while the A-branch electron transfer is slowed in comparison with native RCs of Rba. sphaeroides. A bulk of absorption difference spectra was analyzed in the 940-1060 nm range (stimulated emission of excited bacteriochlorophyll dimer P* and absorption of bacteriochlorophyll anions B(A)(-) and beta(-), where beta is a bacteriochlorophyll substituting the native bacteriopheophytin H(A)) and in the 735-775 nm range (bleaching of the absorption band of the bacteriopheophytin H(B) in the B-branch) in the -0.1 to 4 psec range of delays with respect to the moment of photoexcitation of P at 870 nm. Spectra were measured at 293 and 90 K. The kinetics of P* stimulated emission at 940 nm shows its decay with a time constant of approximately 14 psec at 90 K and approximately 18 psec at 293 K, which is accompanied by oscillations with a frequency of approximately 150 cm(-1). A weak absorption band is found at 1018 nm that is formed approximately 100 fsec after excitation of P and reflects the electron transfer from P* to beta and/or B(A) with accumulation of the P(+)beta(-) and/or P(+)B(A)(-) states. The kinetics of DeltaA at 1018 nm contains the oscillations at approximately 150 cm(-1) and distinct low-frequency oscillations at 20-100 cm(-1); also, the amplitude of the oscillations at 150 cm(-1) is much smaller at 293 than at 90 K. The oscillations in the kinetics of the 1018 nm band do not contain a 32 cm(-1) mode that is characteristic for native Rba. sphaeroides RCs having water molecule HOH55 in their structure. The DeltaA kinetics at 751 nm reflects the electron transfer to H(B) with formation of the P(+)H(B)(-) state. The oscillatory part of

  8. Bioaugmentation of Lactobacillus delbrueckii ssp. bulgaricus TISTR 895 to enhance bio-hydrogen production of Rhodobacter sphaeroides KKU-PS5.

    Science.gov (United States)

    Laocharoen, Sucheera; Reungsang, Alissara; Plangklang, Pensri

    2015-01-01

    Bioaugmentation or an addition of the desired microorganisms or specialized microbial strains into the anaerobic digesters can enhance the performance of microbial community in the hydrogen production process. Most of the studies focused on a bioaugmentation of native microorganisms capable of producing hydrogen with the dark-fermentative hydrogen producers while information on bioaugmentation of purple non-sulfur photosynthetic bacteria (PNSB) with lactic acid-producing bacteria (LAB) is still limited. In our study, bioaugmentation of Rhodobacter sphaeroides KKU-PS5 with Lactobacillus delbrueckii ssp. bulgaricus TISTR 895 was conducted as a method to produce hydrogen. Unfortunately, even though well-characterized microorganisms were used in the fermentation system, a cultivation of two different organisms in the same bioreactor was still difficult because of the differences in their metabolic types, optimal conditions, and nutritional requirements. Therefore, evaluation of the physical and chemical factors affecting hydrogen production of PNSB augmented with LAB was conducted using a full factorial design followed by response surface methodology (RSM) with central composite design (CCD). A suitable LAB/PNSB ratio and initial cell concentration were found to be 1/12 (w/w) and 0.15 g/L, respectively. The optimal initial pH, light intensity, and Mo concentration obtained from RSM with CCD were 7.92, 8.37 klux and 0.44 mg/L, respectively. Under these optimal conditions, a cumulative hydrogen production of 3396 ± 66 mL H2/L, a hydrogen production rate (HPR) of 9.1 ± 0.2 mL H2/L h, and a hydrogen yield (HY) of 9.65 ± 0.23 mol H2/mol glucose were obtained. KKU-PS5 augmented with TISTR 895 produced hydrogen from glucose at a relatively high HY, 9.65 ± 0.23 mol H2/mol glucose, i.e., 80 % of the theoretical yield. The ratio of the strains TISTR 895/KKU-PS5 and their initial cell concentrations affected the rate of lactic acid production and its

  9. Heterologous Production of the Photosynthetic Reaction Center and Light Harvesting 1 Complexes of the Thermophile Thermochromatium tepidum in the Mesophile Rhodobacter sphaeroides and Thermal Stability of a Hybrid Core Complex.

    Science.gov (United States)

    Jun, D; Huang, V; Beatty, J T

    2017-10-15

    The photosynthetic complexes of the thermophile Thermochromatium tepidum are of considerable interest in biohybrid solar cell applications because of the ability of thermophilic proteins to tolerate elevated temperatures. Synthetic operons encoding reaction center (RC) and light harvesting 1 (LH1) pigment-protein complexes of T. tepidum were expressed in the mesophile Rhodobacter sphaeroides The T. tepidum RC (TRC) was assembled and was found to be functional with the addition of menadione to populate the QA pocket. The production of T. tepidum LH1 (TLH1) was increased by selection of a phototrophy-capable mutant after UV irradiation mutagenesis, which yielded a hybrid RC-TLH1 core complex consisting of the R. sphaeroides RC and T. tepidum TLH1, confirmed by the absorbance peak of TLH1 at 915 nm. Affinity chromatography partial purification and subsequent sucrose gradient analysis of the hybrid RC-TLH1 core complex indicated that this core complex assembled as a monomer. Furthermore, the RC-TLH1 hybrid core complex was more tolerant of a temperature of 70°C than the R. sphaeroides RC-LH1 core complexes in both the dimeric and monomeric forms; after 1 h, the hybrid complex retained 58% of the initial starting value, compared to values of 11% and 53% for the R. sphaeroides RC-LH1 dimer and monomer forms, respectively.IMPORTANCE This work is important because it is a new approach to bioengineering of photosynthesis proteins for potential use in biophotovoltaic solar energy capture. The work establishes a proof of principle for future biohybrid solar cell applications. Copyright © 2017 American Society for Microbiology.

  10. Effect of co-substrate on production of poly-β- hydroxybutyrate (PHB and copolymer PHBV from newly identified mutant Rhodobacter sphaeroides U7 cultivated under aerobic-dark condition

    Directory of Open Access Journals (Sweden)

    Kemarajt Kemavongse

    2007-07-01

    Full Text Available Photosynthetic bacterial mutant strain U7 was identified using both classical and molecular (16S rDNA techniques to be Rhodobacter sphaeroides. The glutamate-acetate (GA medium containing sodium acetate and sodium glutamate as carbon and nitrogen sources was used for production of poly-β-hydroxybutyrate (PHB from R. sphaeroides U7 cultivated under aerobic-dark condition (200 rpm at 37oC. Effect of auxiliary carbon sources (propionate and valerate and concentrations (molar ratio of 40/0, 40/20, 40/40 and 40/80 on copolymer production were studied. Both combinations of acetate with valerate and acetate with propionate were found to induce the accumulation of poly-β-hydroxybutyrate-co-β-hydroxyvalerate (PHBV within the cell. Acetate with propionate in the molar ratio of 40/40 gave the highest poly-β-hydroxyalkanoates (PHA content (77.68%, followed by acetate with valerate at the same molar ratio (77.42%. Although their polymer contents were similar, the presence of 40 mM valerate gave more than 4 times higher hydroxyvalerate (HV fraction (84.77% than in the presence of 40 mM propionate (19.12% HV fraction.

  11. The effect of light and temperature on the dynamic state of Rhodobacter sphaeroides reaction centers proteins determined from changes in tryptophan fluorescence lifetime and P+QA-recombination kinetics.

    Science.gov (United States)

    Knox, Peter P; Gorokhov, Vladimir V; Korvatovskiy, Boris N; Lukashev, Eugene P; Goryachev, Sergey N; Paschenko, Vladimir Z; Rubin, Andrew B

    2018-02-06

    The temperature dependencies of the rate of dark recombination of separated charges between the photoactive bacteriochlorophyll and the primary quinone acceptor (Q A ) in photosynthetic reaction centers (RCs) of the purple bacteria Rhodobacter sphaeroides (Rb. sphaeroides) were investigated. Measurements were performed in water-glycerol and trehalose environments after freezing to -180 °C in the dark and under actinic light with subsequent heating. Simultaneously, the RC tryptophanyl fluorescence lifetime in the spectral range between 323 and 348 nm was measured under these conditions. A correlation was found between the temperature dependencies of the functional and dynamic parameters of RCs in different solvent mixtures. For the first time, differences in the average fluorescence lifetime of tryptophanyl residues were measured between RCs frozen in the dark and in the actinic light. The obtained results can be explained by the RC transitions between different conformational states and the dynamic processes in the structure of the hydrogen bonds of RCs. We assumed that RCs exist in two main microconformations - "fast" and "slow", which are characterized by different rates of P + and Q A - recombination reactions. The "fast" conformation is induced in frozen RCs in the dark, while the "slow" conformation of RC occurs when the RC preparation is frozen under actinic light. An explanation of the temperature dependencies of tryptophan fluorescence lifetimes in RC proteins was made under the assumption that temperature changes affect mainly the electron transfer from the indole ring of the tryptophan molecule to the nearest amide or carboxyl groups. Copyright © 2018. Published by Elsevier B.V.

  12. Identification of unsaturated N-acylhomoserine lactones in bacterial isolates of Rhodobacter sphaeroides by liquid chromatography coupled to electrospray ionization-hybrid linear ion trap-Fourier transform ion cyclotron resonance mass spectrometry.

    Science.gov (United States)

    Cataldi, Tommaso R I; Bianco, Giuliana; Abate, Salvatore; Losito, Ilario

    2011-07-15

    The identification of two unsaturated N-acylhomoserine lactones (AHLs) produced by Rhodobacter sphaeroides bacteria, based on liquid chromatography (LC) coupled to a hybrid quadrupole linear ion trap (LTQ)-Fourier transform ion cyclotron resonance (FTICR) mass spectrometer upon electrospray ionization (ESI), is presented. Besides the confirmation of the signaling molecule already described in the literature, i.e. (Z)-N-tetradec-7-enoyl-homoserine lactone (C(14:1)-HSL), we have discovered the occurrence, at low, yet significant levels, of another monounsaturated compound, C(12:1) -HSL, which may extend the number of small diffusible chemical signals known for R. sphaeroides. Both unsaturated AHLs were identified by high-resolution FTICR mass spectrometry in extracts of bacterial culture media and the occurrence of a C=C bond was assessed upon their conversion into bromohydrins. Collision-induced dissociation (CID) spectra were then collected on the LTQ mass analyzer. A careful comparison of tandem MS spectra of monounsaturated (i.e., C(12:1)-HSL and C(14:1)-HSL) and saturated AHLs (i.e. C(12)-HSL and C(14)-HSL) led to the emphasis of two series of product ions, exhibiting 14 Da spaced m/z ratios. Both series were referred to progressive fragmentations at the aliphatic end of the AHL acyl chains, followed by neutral losses of terminal alkenes (i.e. CH(2)=CH(CH(2))(n)H). In particular, the series located at the higher end of the explored m/z range (>200 Da), observed only for monounsaturated species, enabled the location of the C=C bond between carbons 7 and 8 of the acyl chain. Copyright © 2011 John Wiley & Sons, Ltd.

  13. The crystal structures of the tri-functional Chloroflexus aurantiacus and bi-functional Rhodobacter sphaeroides malyl-CoA lyases and comparison with CitE-like superfamily enzymes and malate synthases.

    Science.gov (United States)

    Zarzycki, Jan; Kerfeld, Cheryl A

    2013-11-09

    Malyl-CoA lyase (MCL) is a promiscuous carbon-carbon bond lyase that catalyzes the reversible cleavage of structurally related Coenzyme A (CoA) thioesters. This enzyme plays a crucial, multifunctional role in the 3-hydroxypropionate bi-cycle for autotrophic CO2 fixation in Chloroflexus aurantiacus. A second, phylogenetically distinct MCL from Rhodobacter sphaeroides is involved in the ethylmalonyl-CoA pathway for acetate assimilation. Both MCLs belong to the large superfamily of CitE-like enzymes, which includes the name-giving β-subunit of citrate lyase (CitE), malyl-CoA thioesterases and other enzymes of unknown physiological function. The CitE-like enzyme superfamily also bears sequence and structural resemblance to the malate synthases. All of these different enzymes share highly conserved catalytic residues, although they catalyze distinctly different reactions: C-C bond formation and cleavage, thioester hydrolysis, or both (the malate synthases). Here we report the first crystal structures of MCLs from two different phylogenetic subgroups in apo- and substrate-bound forms. Both the C. aurantiacus and the R. sphaeroides MCL contain elaborations on the canonical β8/α8 TIM barrel fold and form hexameric assemblies. Upon ligand binding, changes in the C-terminal domains of the MCLs result in closing of the active site, with the C-terminal domain of one monomer forming a lid over and contributing side chains to the active site of the adjacent monomer. The distinctive features of the two MCL subgroups were compared to known structures of other CitE-like superfamily enzymes and to malate synthases, providing insight into the structural subtleties that underlie the functional versatility of these enzymes. Although the C. aurantiacus and the R. sphaeroides MCLs have divergent primary structures (~37% identical), their tertiary and quaternary structures are very similar. It can be assumed that the C-C bond formation catalyzed by the MCLs occurs as proposed for

  14. Comparing the temperature dependence of photosynthetic electron transfer in Chloroflexus aurantiacus and Rhodobactor sphaeroides reaction centers.

    Science.gov (United States)

    Guo, Zhi; Lin, Su; Xin, Yueyong; Wang, Haiyu; Blankenship, Robert E; Woodbury, Neal W

    2011-09-29

    The process of electron transfer from the special pair, P, to the primary electron donor, H(A), in quinone-depleted reaction centers (RCs) of Chloroflexus (Cf.) aurantiacus has been investigated over the temperature range from 10 to 295 K using time-resolved pump-probe spectroscopic techniques. The kinetics of the electron transfer reaction, P* → P(+)H(A)(-), was found to be nonexponential, and the degree of nonexponentiality increased strongly as temperature decreased. The temperature-dependent behavior of electron transfer in Cf. aurantiacus RCs was compared with that of the purple bacterium Rhodobacter (Rb.) sphaeroides . Distinct transitions were found in the temperature-dependent kinetics of both Cf. aurantiacus and Rb. sphaeroides RCs, at around 220 and 160 K, respectively. Structural differences between these two RCs, which may be associated with those differences, are discussed. It is suggested that weaker protein-cofactor hydrogen bonding, stronger electrostatic interactions at the protein surface, and larger solvent interactions likely contribute to the higher transition temperature in Cf. aurantiacus RCs temperature-dependent kinetics compared with that of Rb. sphaeroides RCs. The reaction-diffusion model provides an accurate description for the room-temperature electron transfer kinetics in Cf. aurantiacus RCs with no free parameters, using coupling and reorganization energy values previously determined for Rb. sphaeroides , along with an experimental measure of protein conformational diffusion dynamics and an experimental literature value of the free energy gap between P* and P(+)H(A)(-). © 2011 American Chemical Society

  15. The reductive phase of Rhodobacter sphaeroides cytochrome c oxidase disentangled by CO ligation.

    Science.gov (United States)

    Mohrmann, Hendrik; Dragelj, Jovan; Baserga, Federico; Knapp, Ernst-Walter; Stripp, Sven T; Heberle, Joachim

    2017-10-25

    Cytochrome c oxidase (CcO) is a membrane protein of the respiratory chain that catalytically reduces molecular oxygen (O 2 ) to water while translocating protons across the membrane. The enzyme hosts two copper and two heme iron moieties (heme a/heme a 3 ). The atomic details of the sequential steps that go along with this redox-driven proton translocation are a matter of debate. Particularly for the reductive phase of CcO that precedes oxygen binding experimental data are scarce. Here, we use CcO under anaerobic conditions where carbon monoxide (CO) is bound to heme a 3 which in tandem with Cu B forms the binuclear center (BNC). Fourier-transform infrared (FTIR) absorption spectroscopy is combined with electro-chemistry to probe different redox and protonation states populated by variation of the external electrostatic potential. With this approach, the redox behavior of heme a and the BNC could be separated and the corresponding redox potentials were determined. We also infer the protonation of one of the propionate side chains of heme a 3 to correlate with the oxidation of heme a. Experimental changes in the local electric field surrounding CO bound to heme a 3 are determined by their vibrational Stark effect and agree well with electrostatic computations. The comparison of experimental and computational results indicates that changes of the heme a 3 /Cu B redox state are coupled to proton transfer towards heme a 3 . The latter supports the role of the heme a 3 propionate D as proton loading site.

  16. Mutations to R. sphaeroides Reaction Center Perturb Energy Levels and Vibronic Coupling but Not Observed Energy Transfer Rates.

    Science.gov (United States)

    Flanagan, Moira L; Long, Phillip D; Dahlberg, Peter D; Rolczynski, Brian S; Massey, Sara C; Engel, Gregory S

    2016-03-10

    The bacterial reaction center is capable of both efficiently collecting and quickly transferring energy within the complex; therefore, the reaction center serves as a convenient model for both energy transfer and charge separation. To spectroscopically probe the interactions between the electronic excited states on the chromophores and their intricate relationship with vibrational motions in their environment, we examine coherences between the excited states. Here, we investigate this question by introducing a series of point mutations within 12 Å of the special pair of bacteriochlorophylls in the Rhodobacter sphaeroides reaction center. Using two-dimensional spectroscopy, we find that the time scales of energy transfer dynamics remain unperturbed by these mutations. However, within these spectra, we detect changes in the mixed vibrational-electronic coherences in these reaction centers. Our results indicate that resonance between bacteriochlorophyll vibrational modes and excitonic energy gaps promote electronic coherences and support current vibronic models of photosynthetic energy transfer.

  17. The molybdenum cofactor biosynthesis protein MobA from Rhodobacter capsulatus is required for the activity of molybdenum enzymes containing MGD, but not for xanthine dehydrogenase harboring the MPT cofactor.

    Science.gov (United States)

    Leimkühler, S; Klipp, W

    1999-05-15

    The requirement of MobA for molybdoenzymes with different molybdenum cofactors was analyzed in Rhodobacter capsulatus. MobA is essential for DMSO reductase and nitrate reductase activity, both enzymes containing the molybdopterin guanine dinucleotide cofactor (MGD), but not for active xanthine dehydrogenase, harboring the molybdopterin cofactor. In contrast to the mob locus of Escherichia coli and R. sphaeroides, the mobB gene is not located downstream of mobA in R. capsulatus. The mobA gene is expressed constitutively at low levels and no increase in mobA expression could be observed even under conditions of high MGD demand.

  18. Nontoxic lipopolysaccharide from Rhodopseudomonas sphaeroides ATCC 17023.

    OpenAIRE

    Strittmatter, W; Weckesser, J; Salimath, P V; Galanos, C

    1983-01-01

    Chemical analysis of the lipopolysaccharide from Rhodopseudomonas sphaeroides ATCC 17023, isolated by the phenol-chloroform-petroleum ether method, revealed the presence of glucuronic acid, 2-keto-3-deoxyoctonate, threonine, and phosphorus in the polysaccharide moiety. The lipid A component contained glucosamine, glucosamine phosphate, amide-bound 3-oxotetradecanoic acid and 3-hydroxytetradecanoic acid, and ester-bound 3-hydroxydecanoic acid and 7-tetradecenoic acid. Structural similarity of ...

  19. Insights into the species-specific TLR4 signaling mechanism in response to Rhodobacter sphaeroides lipid A detection

    National Research Council Canada - National Science Library

    Anwar, Muhammad Ayaz; Panneerselvam, Suresh; Shah, Masaud; Choi, Sangdun

    2015-01-01

    ...). Penta-acyl chain-containing RsLA is at the verge of agonist (6 acyl-chains) and antagonist (4 acyl-chains) structure, and activates the TLR4 pathway in horses and hamsters, while inhibiting in humans and murine...

  20. Electron spin relaxation enhancement measurements of interspin distances in human, porcine, and Rhodobacter electron transfer flavoprotein ubiquinone oxidoreductase (ETF QO)

    Science.gov (United States)

    Fielding, Alistair J.; Usselman, Robert J.; Watmough, Nicholas; Simkovic, Martin; Frerman, Frank E.; Eaton, Gareth R.; Eaton, Sandra S.

    2008-02-01

    Electron transfer flavoprotein-ubiquinone oxidoreductase (ETF-QO) is a membrane-bound electron transfer protein that links primary flavoprotein dehydrogenases with the main respiratory chain. Human, porcine, and Rhodobacter sphaeroides ETF-QO each contain a single [4Fe-4S] 2+,1+ cluster and one equivalent of FAD, which are diamagnetic in the isolated enzyme and become paramagnetic on reduction with the enzymatic electron donor or with dithionite. The anionic flavin semiquinone can be reduced further to diamagnetic hydroquinone. The redox potentials for the three redox couples are so similar that it is not possible to poise the proteins in a state where both the [4Fe-4S] + cluster and the flavoquinone are fully in the paramagnetic form. Inversion recovery was used to measure the electron spin-lattice relaxation rates for the [4Fe-4S] + between 8 and 18 K and for semiquinone between 25 and 65 K. At higher temperatures the spin-lattice relaxation rates for the [4Fe-4S] + were calculated from the temperature-dependent contributions to the continuous wave linewidths. Although mixtures of the redox states are present, it was possible to analyze the enhancement of the electron spin relaxation of the FAD semiquinone signal due to dipolar interaction with the more rapidly relaxing [4Fe-4S] + and obtain point-dipole interspin distances of 18.6 ± 1 Å for the three proteins. The point-dipole distances are within experimental uncertainty of the value calculated based on the crystal structure of porcine ETF-QO when spin delocalization is taken into account. The results demonstrate that electron spin relaxation enhancement can be used to measure distances in redox poised proteins even when several redox states are present.

  1. Electron spin relaxation enhancement measurements of interspin distances in human, porcine, and Rhodobacter electron transfer flavoprotein-ubiquinone oxidoreductase (ETF-QO).

    Science.gov (United States)

    Fielding, Alistair J; Usselman, Robert J; Watmough, Nicholas; Simkovic, Martin; Frerman, Frank E; Eaton, Gareth R; Eaton, Sandra S

    2008-02-01

    Electron transfer flavoprotein-ubiquinone oxidoreductase (ETF-QO) is a membrane-bound electron transfer protein that links primary flavoprotein dehydrogenases with the main respiratory chain. Human, porcine, and Rhodobacter sphaeroides ETF-QO each contain a single [4Fe-4S](2+,1+) cluster and one equivalent of FAD, which are diamagnetic in the isolated enzyme and become paramagnetic on reduction with the enzymatic electron donor or with dithionite. The anionic flavin semiquinone can be reduced further to diamagnetic hydroquinone. The redox potentials for the three redox couples are so similar that it is not possible to poise the proteins in a state where both the [4Fe-4S](+) cluster and the flavoquinone are fully in the paramagnetic form. Inversion recovery was used to measure the electron spin-lattice relaxation rates for the [4Fe-4S](+) between 8 and 18K and for semiquinone between 25 and 65K. At higher temperatures the spin-lattice relaxation rates for the [4Fe-4S](+) were calculated from the temperature-dependent contributions to the continuous wave linewidths. Although mixtures of the redox states are present, it was possible to analyze the enhancement of the electron spin relaxation of the FAD semiquinone signal due to dipolar interaction with the more rapidly relaxing [4Fe-4S](+) and obtain point-dipole interspin distances of 18.6+/-1A for the three proteins. The point-dipole distances are within experimental uncertainty of the value calculated based on the crystal structure of porcine ETF-QO when spin delocalization is taken into account. The results demonstrate that electron spin relaxation enhancement can be used to measure distances in redox poised proteins even when several redox states are present.

  2. PucC and LhaA direct efficient assembly of the light-harvesting complexes in Rhodobacter sphaeroides

    DEFF Research Database (Denmark)

    Mothersole, David; Jackson, Philip J.; Vasilev, Cvetelin

    2016-01-01

    . Here we investigate the assembly of light-harvesting LH2 and reaction centre-light-harvesting1-PufX (RC-LH1-PufX) photosystem complexes using spectroscopy, pull-downs, native gel electrophoresis, quantitative mass spectrometry and fluorescence lifetime microscopy to characterise a series of lha...

  3. Bioaugmentation of Lactobacillus delbrueckii ssp. bulgaricus TISTR 895 to enhance bio-hydrogen production of Rhodobacter sphaeroides KKU-PS5

    National Research Council Canada - National Science Library

    Laocharoen, Sucheera; Reungsang, Alissara; Plangklang, Pensri

    2015-01-01

    Bioaugmentation or an addition of the desired microorganisms or specialized microbial strains into the anaerobic digesters can enhance the performance of microbial community in the hydrogen production process...

  4. Hydrogen production from starch by co-culture of Clostridium acetobutylicum and Rhodobacter sphaeroides in one step hybrid dark- and photofermentation in repeated fed-batch reactor.

    Science.gov (United States)

    Zagrodnik, R; Łaniecki, M

    2017-01-01

    Hydrogen production from starch by a co-culture hybrid dark and photofermentation under repeated fed-batch conditions at different organic loading rates (OLR) was studied. Effective cooperation between bacteria in co-culture during initial days was observed at controlled pH 7.0. However, at pH above 6.5 dark fermentation phase was redirected from H2 formation towards production of formic acid, lactic acid and ethanol (which are not coupled with hydrogen production) with simultaneous lower starch removal efficiency. This resulted in decrease in the hydrogen production rate. The highest H2 production in co-culture process (3.23LH2/Lmedium - after 11days) was achieved at OLR of 1.5gstarch/L/day, and it was twofold higher than for dark fermentation process (1.59LH2/Lmedium). The highest H2 yield in the co-culture (2.62molH2/molhexose) was obtained at the OLR of 0.375gstarch/L/day. Different pH requirements of bacteria were proven to be a key limitation in co-culture system. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Reprint of “Extracellular production of tellurium nanoparticles by the photosynthetic bacterium Rhodobacter capsulatus”

    Energy Technology Data Exchange (ETDEWEB)

    Borghese, Roberto, E-mail: roberto.borghese@unibo.it [Dept. of Pharmacy and Biotechnology, University of Bologna (Italy); Brucale, Marco [Institute for the Study of Nanostructured Materials (CNR-ISMN), Rome (Italy); Fortunato, Gianuario [Dept. of Pharmacy and Biotechnology, University of Bologna (Italy); Lanzi, Massimiliano [Dept. of Industrial Chemistry “Toso Montanari”, University of Bologna (Italy); Mezzi, Alessio [Institute for the Study of Nanostructured Materials (CNR-ISMN), Rome (Italy); Valle, Francesco; Cavallini, Massimiliano [Institute for the Study of Nanostructured Materials (CNR-ISMN), Bologna (Italy); Zannoni, Davide [Dept. of Pharmacy and Biotechnology, University of Bologna (Italy)

    2017-02-15

    Highlights: • Tellurite is reduced by R. capsulatus as cytosolic tellurium nanoprecipitates TeNPs. • Lawsone allows R. capsulatus to produce extracellular TeNPs. • Extracellular TeNPs production depends on the carbon source used for cells growth. • Both lawsone concentration and the incubation time determine the TeNPs size. • Extracellular TeNPs are coated with extracellular polymeric substances (EPS). - Abstract: The toxic oxyanion tellurite (TeO{sub 3}{sup 2−}) is acquired by cells of Rhodobacter capsulatus grown anaerobically in the light, via acetate permease ActP2 and then reduced to Te{sup 0} in the cytoplasm as needle-like black precipitates. Interestingly, photosynthetic cultures of R. capsulatus can also generate Te{sup 0} nanoprecipitates (TeNPs) outside the cells upon addition of the redox mediator lawsone (2-hydroxy-1,4-naphtoquinone). TeNPs generation kinetics were monitored to define the optimal conditions to produce TeNPs as a function of various carbon sources and lawsone concentration. We report that growing cultures over a 10 days period with daily additions of 1 mM tellurite led to the accumulation in the growth medium of TeNPs with dimensions from 200 up to 600–700 nm in length as determined by atomic force microscopy (AFM). This result suggests that nucleation of TeNPs takes place over the entire cell growth period although the addition of new tellurium Te{sup 0} to pre-formed TeNPs is the main strategy used by R. capsulatus to generate TeNPs outside the cells. Finally, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR) analysis of TeNPs indicate they are coated with an organic material which keeps the particles in solution in aqueous solvents.

  6. Extracellular production of tellurium nanoparticles by the photosynthetic bacterium Rhodobacter capsulatus

    Energy Technology Data Exchange (ETDEWEB)

    Borghese, Roberto, E-mail: roberto.borghese@unibo.it [Dept. of Pharmacy and Biotechnology, University of Bologna (Italy); Brucale, Marco [Institute for the Study of Nanostructured Materials (CNR-ISMN), Rome (Italy); Fortunato, Gianuario [Dept. of Pharmacy and Biotechnology, University of Bologna (Italy); Lanzi, Massimiliano [Dept. of Industrial Chemistry “Toso Montanari”, University of Bologna (Italy); Mezzi, Alessio [Institute for the Study of Nanostructured Materials (CNR-ISMN), Rome (Italy); Valle, Francesco; Cavallini, Massimiliano [Institute for the Study of Nanostructured Materials (CNR-ISMN), Bologna (Italy); Zannoni, Davide [Dept. of Pharmacy and Biotechnology, University of Bologna (Italy)

    2016-05-15

    Highlights: • Tellurite is reduced by R. capsulatus as cytosolic tellurium nanoprecipitates TeNPs. • Lawsone allows R. capsulatus to produce extracellular TeNPs. • Extracellular TeNPs production depends on the carbon source used for cells growth. • Both lawsone concentration and the incubation time determine the TeNPs size. • Extracellular TeNPs are coated with extracellular polymeric substances (EPS). - Abstract: The toxic oxyanion tellurite (TeO{sub 3}{sup 2−}) is acquired by cells of Rhodobacter capsulatus grown anaerobically in the light, via acetate permease ActP2 and then reduced to Te{sup 0} in the cytoplasm as needle-like black precipitates. Interestingly, photosynthetic cultures of R. capsulatus can also generate Te{sup 0} nanoprecipitates (TeNPs) outside the cells upon addition of the redox mediator lawsone (2-hydroxy-1,4-naphtoquinone). TeNPs generation kinetics were monitored to define the optimal conditions to produce TeNPs as a function of various carbon sources and lawsone concentration. We report that growing cultures over a 10 days period with daily additions of 1 mM tellurite led to the accumulation in the growth medium of TeNPs with dimensions from 200 up to 600–700 nm in length as determined by atomic force microscopy (AFM). This result suggests that nucleation of TeNPs takes place over the entire cell growth period although the addition of new tellurium Te{sup 0} to pre-formed TeNPs is the main strategy used by R. capsulatus to generate TeNPs outside the cells. Finally, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR) analysis of TeNPs indicate they are coated with an organic material which keeps the particles in solution in aqueous solvents.

  7. Protein film voltammetry of Rhodobacter capsulatus xanthine dehydrogenase.

    Science.gov (United States)

    Aguey-Zinsou, Kondo François; Bernhardt, Paul V; Leimkühler, Silke

    2003-12-17

    Xanthine dehydrogenase (XDH) from the bacterium Rhodobacter capsulatus catalyzes the hydroxylation of xanthine to uric acid with NAD(+) as the electron acceptor. R. capsulatus XDH forms an (alphabeta)(2) heterotetramer and is highly homologous to homodimeric eukaryotic XDHs. The crystal structures of bovine XDH and R. capsulatus XDH showed that the two proteins have highly similar folds; however, R.capsulatus XDH is at least 5 times more active than bovine XDH and, unlike mammalian XDH, does not undergo the conversion to the oxidase form. Here we demonstrate electrocatalytic activity of the recombinant enzyme, expressed in Escherichia coli, while immobilized on an edge plane pyrolytic graphite working electrode. Furthermore, we have determined all redox potentials of the four cofactors (Mo(VI/V), Mo(V/IV), FAD/FADH, FADH/FADH(2) and two distinct [2Fe-2S](2+/+) clusters) using a combination of potentiometric and voltammetric methods. A novel feature identified in catalytic voltammetry of XDH concerns the potential for the onset of catalysis (ca. 400 mV), which is at least 600 mV more positive than that of the highest potential cofactor. This unusual observation is explained on the basis of a pterin-associated oxidative switch during voltammetry that precedes catalysis.

  8. Electrochemical determination of hydrogen peroxide using Rhodobacter capsulatus cytochrome c peroxidase at a gold electrode

    NARCIS (Netherlands)

    De Wael, K.; Buschop, H.; Heering, H.A.; De Smet, L.; Van Beeumen, J.; Devreese, B.; Adriaens, A.

    2007-01-01

    We describe the redox behaviour of horse heart cytochrome c (HHC) and Rhodobacter capsulatus cytochrome c peroxidase (RcCCP) at a gold electrode modified with 4,4?-bipyridyl. RcCCP shows no additional oxidation or reduction peaks compared to the electrochemistry of only HHC, which indicates that it

  9. NCBI nr-aa BLAST: CBRC-OLAT-26-0102 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-OLAT-26-0102 ref|YP_001033817.1| Ice nucleation protein [Rhodobacter sphaeroid...es 2.4.1] gb|ABA81712.1| Ice nucleation protein [Rhodobacter sphaeroides 2.4.1] YP_001033817.1 0.45 25% ...

  10. NCBI nr-aa BLAST: CBRC-XTRO-01-0267 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-XTRO-01-0267 ref|YP_001033817.1| Ice nucleation protein [Rhodobacter sphaeroid...es 2.4.1] gb|ABA81712.1| Ice nucleation protein [Rhodobacter sphaeroides 2.4.1] YP_001033817.1 6e-27 25% ...

  11. NCBI nr-aa BLAST: CBRC-OGAR-01-0310 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-OGAR-01-0310 ref|YP_001033817.1| Ice nucleation protein [Rhodobacter sphaeroid...es 2.4.1] gb|ABA81712.1| Ice nucleation protein [Rhodobacter sphaeroides 2.4.1] YP_001033817.1 4e-07 24% ...

  12. NCBI nr-aa BLAST: CBRC-XTRO-01-0470 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-XTRO-01-0470 ref|YP_001033817.1| Ice nucleation protein [Rhodobacter sphaeroid...es 2.4.1] gb|ABA81712.1| Ice nucleation protein [Rhodobacter sphaeroides 2.4.1] YP_001033817.1 1e-12 25% ...

  13. Effects of light intensity and quality on phycobiliprotein accumulation in the cyanobacterium Nostoc sphaeroides Kützing.

    Science.gov (United States)

    Ma, Rui; Lu, Fan; Bi, Yonghong; Hu, Zhengyu

    2015-08-01

    To assess the effects of light intensity and quality on the growth and phycobiliproteins (PBP) accumulation in Nostoc sphaeroides Kützing (N. sphaeroides). Dry weights, dry matter, protein, chlorophyll and PBP contents were higher under 90 μmol m(-2) s(-1) than under other intensities (both higher and lower). Phycocyanin and allophycocyanin increased with light intensity while phycoerythrin decreased. Fresh weights, protein and PBP contents increased at the highest rates under blue light. Red light resulted in higher values of dry matter, phycocyanin and chlorophyll a. White light at 90 μmol m(-2) s(-1) or blue light 30 μmol m(-2) s(-1) were optimal for the growth and phycobiliprotein accumulation in N. sphaeroides.

  14. Growing Pains

    CERN Multimedia

    Katarina Anthony

    2013-01-01

    Heat expands and cold contracts: it’s a simple thermodynamic rule. But when temperatures swing from 300 K to near-absolute zero, this rule can mean a contraction of more than 80 metres across the LHC’s 27-km-long cryogenic system. Keeping this growth in check are compensators (a.k.a. bellows), which shrink and stretch in response to thermodynamic changes. Leak tests and X-rays now underway in the tunnel have revealed that these “joints” might be suffering from growing pains…   This 25-μm weld crack is thought to be the cause of the helium leaks. Prior to the LS1 warm-up, CERN’s cryogenic experts knew of two points in the machine’s cryogenic distribution system that were leaking helium. Fortunately, these leaks were sufficiently small, confined to known sub-sectors of the cryogenic line and – with help from the vacuum team (TE-VSC) – could easily be compensated for. But as the machine warmed up f...

  15. Embryonic, Larval, and Early Juvenile Development of the Tropical Sea Urchin, Salmacis sphaeroides (Echinodermata: Echinoidea

    Directory of Open Access Journals (Sweden)

    M. Aminur Rahman

    2012-01-01

    Full Text Available Salmacis sphaeroides (Linnaeus, 1758 is one of the regular echinoids, occuring in the warm Indo-West Pacific, including Johor Straits, between Malaysia and Singapore. In order to investigate the developmental basis of morphological changes in embryos and larvae, we documented the ontogeny of S. sphaeroides in laboratory condition. Gametes were obtained from adult individuals by 0.5 M KCl injection into the coelomic cavity. Fertilization rate at limited sperm concentration (10−5 dilution was 96.6±1.4% and the resulting embryos were reared at 24°C. First cleavage (2-cell, 4-cell, 8-cell, 16-cell, 32-cell, and multicell (Morulla stages were achieved 01.12, 02.03, 02.28, 02.51, 03.12, and 03.32 h postfertilization. Ciliated blastulae with a mean length of 174.72±4.43 μm hatched 08.45 h after sperm entry. The gastrulae formed 16.15 h postfertilization and the archenteron elongated constantly while ectodermal red-pigmented cells migrated synchronously to the apical plate. Pluteus larva started to feed unicellular algae in 2 d, grew continuously, and finally attained metamorphic competence in 35 d after fertilization. Metamorphosis took approximately 1 h 30 min from attachment to the complete resorption of larval tissues and the development of complete juvenile structure with adult spines, extended tubefeet and well-developed pedicellaria, the whole event of which usually took place within 1 d postsettlement. This study represents the first successful investigation on embryonic, larval, and early juvenile development of S. sphaeroides. The findings would greatly be helpful towards the understanding of ontogeny and life-history strategies, which will facilitate us to develop the breeding, seed production, and culture techniques of sea urchins in captive condition.

  16. In vitro biosynthesis and membrane association of photosynthetic reaction center subunits for Rhodopseudomonas sphaeroides

    Energy Technology Data Exchange (ETDEWEB)

    Hoger, J.H.; Chory, J.; Kaplan, S.

    1986-03-01

    The reaction center of Rhodopseudomonas sphaeroides is an integral membrane protein complex responsible for primary photochemical charge separation in photosynthesis. The authors report the synthesis of two of the three subunits of the photosynthetic reaction center using a DNA-directed in vitro transcription-translation system prepared from R. sphaeroides. The in vitro-synthesized polypeptides, as resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, had apparent M/sub r/s of 24,000 and 21,000 and were shown to be synthesized in equimolar amounts. This corresponds precisely to the in vivo reaction center subunits M and L, respectively. The invitro-synthesized polypeptides were immunoprecipitated with antibody prepared against whole native reaction centers. In addition, the identity of the in vitro-synthesized polypeptides as L and M was verified by comparing the protease digestion products of in vivo- with in vitro-synthesized reaction center subunits. Both of the in vitro-synthesized polypeptides were also found to partition with the particulate material in the transcription-translation system and to associate with added membranes.

  17. The effect of temperature and light intensity on hydrogen production by Rhodobacter capsulatus

    Energy Technology Data Exchange (ETDEWEB)

    Eroglu, Inci [Middle East Technical Univ., Ankara (Turkey). Dept. of Chemical Engineering; Sevinc, Pelin [Middle East Technical Univ., Ankara (Turkey). Dept. of Biotechnology; Guenduez, Ufuk; Yucel, Meral [Middle East Technical Univ., Ankara (Turkey). Dept. of Biological Sciences

    2010-07-01

    Rhodobacter capsulatus is a purple non-sulfur photosynthetic bacterium which can produce hydrogen by photofermentation on acetate and lactate. Hydrogen productivity depends on several parameters such as medium composition, pH, light intensity and temperature. In the present study, the effects of temperature and light intensity on hydrogen production were investigated. The cell growth curve has been fitted to the logistic model and hydrogen productivity was interpreted by Modified Gompertz Equation. The maximum productivity was obtained at 30 C and light intensity of 4000 lux. (orig.)

  18. Role of XDHC in Molybdenum Cofactor Insertion into Xanthine Dehydrogenase of Rhodobacter capsulatus

    OpenAIRE

    Leimkühler, Silke; Klipp, Werner

    1999-01-01

    Rhodobacter capsulatus xanthine dehydrogenase (XDH) is composed of two subunits, XDHA and XDHB. Immediately downstream of xdhB, a third gene was identified, designated xdhC, which is cotranscribed with xdhAB. Interposon mutagenesis revealed that the xdhC gene product is required for XDH activity. However, XDHC is not a subunit of active XDH, which forms an α2β2 heterotetramer in R. capsulatus. It was shown that XDHC neither is a transcriptional regulator for xdh gene expression nor influences...

  19. Chemical proprieties of the iron-quinone complex in mutated reaction centers of Rb. sphaeroides

    Science.gov (United States)

    Hałas, Agnieszka; Derrien, Valerie; Sebban, Pierre; Matlak, Krzysztof; Korecki, Józef; Kruk, Jerzy; Burda, Kvĕtoslava

    2012-03-01

    We investigated type II bacterial photosynthetic reaction centers, which contain a quinone - iron complex (QA-Fe-QB) on their acceptor side. Under physiological conditions it was observed mainly in a reduced high spin state but its low spin ferrous states were also observed. Therefore, it was suggested that it might regulate the dynamical properties of the iron-quinone complex and the protonation and deprotonation events in its neighbourhood. In order to get insight into the molecular mechanism of the NHFe low spin state formation, we preformed Mössbauer studies of a wild type of Rb. sphaeroides and its two mutated forms. Our Mössbauer measurements show that the hydrophobicity of the QA binding site can be crucial for stabilization of the high spin ferrous state of NHFe.

  20. Chemical proprieties of the iron-quinone complex in mutated reaction centers of Rb. sphaeroides

    Energy Technology Data Exchange (ETDEWEB)

    Halas, Agnieszka [AGH University, Faculty of Physics and Computer Science, Department of Medical Physics and Biophysics (Poland); Derrien, Valerie; Sebban, Pierre [University of Paris XI, Laboratoire de Chimie Physique (France); Matlak, Krzysztof; Korecki, Jozef [AGH University, Faculty of Physics and Computer Science, Department of Solid State Physics (Poland); Kruk, Jerzy [Jagiellonian University, Faculty of Biochemistry, Biophysics and Biotechnology (Poland); Burda, Kvetoslava, E-mail: kvetoslava.burda@fis.agh.edu.pl [AGH University, Faculty of Physics and Computer Science, Department of Medical Physics and Biophysics (Poland)

    2012-03-15

    We investigated type II bacterial photosynthetic reaction centers, which contain a quinone - iron complex (Q{sub A}-Fe-Q{sub B}) on their acceptor side. Under physiological conditions it was observed mainly in a reduced high spin state but its low spin ferrous states were also observed. Therefore, it was suggested that it might regulate the dynamical properties of the iron-quinone complex and the protonation and deprotonation events in its neighbourhood. In order to get insight into the molecular mechanism of the NHFe low spin state formation, we preformed Moessbauer studies of a wild type of Rb. sphaeroides and its two mutated forms. Our Moessbauer measurements show that the hydrophobicity of the Q{sub A} binding site can be crucial for stabilization of the high spin ferrous state of NHFe.

  1. Growing and Growing: Promoting Functional Thinking with Geometric Growing Patterns

    Science.gov (United States)

    Markworth, Kimberly A.

    2010-01-01

    Design research methodology is used in this study to develop an empirically-substantiated instruction theory about students' development of functional thinking in the context of geometric growing patterns. The two research questions are: (1) How does students' functional thinking develop in the context of geometric growing patterns? (2) What are…

  2. Growing media [Chapter 5

    Science.gov (United States)

    Douglass F. Jacobs; Thomas D. Landis; Tara Luna

    2009-01-01

    Selecting the proper growing medium is one of the most important considerations in nursery plant production. A growing medium can be defined as a substance through which roots grow and extract water and nutrients. In native plant nurseries, a growing medium can consist of native soil but is more commonly an "artificial soil" composed of materials such as peat...

  3. Structural and Phylogenetic Analysis of Rhodobacter capsulatus NifF: Uncovering General Features of Nitrogen-fixation (nif-Flavodoxins

    Directory of Open Access Journals (Sweden)

    Inmaculada Pérez-Dorado

    2013-01-01

    Full Text Available Analysis of the crystal structure of NifF from Rhodobacter capsulatus and its homologues reported so far reflects the existence of unique structural features in nif flavodoxins: a leucine at the re face of the isoalloxazine, an eight-residue insertion at the C-terminus of the 50’s loop and a remarkable difference in the electrostatic potential surface with respect to non-nif flavodoxins. A phylogenetic study on 64 sequences from 52 bacterial species revealed four clusters, including different functional prototypes, correlating the previously defined as “short-chain” with the firmicutes flavodoxins and the “long-chain” with gram-negative species. The comparison of Rhodobacter NifF structure with other bacterial flavodoxin prototypes discloses the concurrence of specific features of these functional electron donors to nitrogenase.

  4. Structural and phylogenetic analysis of Rhodobacter capsulatus NifF: uncovering general features of nitrogen-fixation (nif)-flavodoxins.

    Science.gov (United States)

    Pérez-Dorado, Inmaculada; Bortolotti, Ana; Cortez, Néstor; Hermoso, Juan A

    2013-01-09

    Analysis of the crystal structure of NifF from Rhodobacter capsulatus and its homologues reported so far reflects the existence of unique structural features in nif flavodoxins: a leucine at the re face of the isoalloxazine, an eight-residue insertion at the C-terminus of the 50's loop and a remarkable difference in the electrostatic potential surface with respect to non-nif flavodoxins. A phylogenetic study on 64 sequences from 52 bacterial species revealed four clusters, including different functional prototypes, correlating the previously defined as "short-chain" with the firmicutes flavodoxins and the "long-chain" with gram-negative species. The comparison of Rhodobacter NifF structure with other bacterial flavodoxin prototypes discloses the concurrence of specific features of these functional electron donors to nitrogenase.

  5. An Ambition to Grow

    OpenAIRE

    Ron Kemp; Hakkert, R.

    2006-01-01

    This report tries to gain insight in the willingness or ambition to grow of a small business owner. The main question of this report is therefore: Which factors influence the ambition to grow a business? To examine the ambition to grow an economic and a psychological perspective is given in this study.

  6. Evidence for a Very Early Intermediate in Bacterial Photosynthesis. A Photon-Echo and Hole-Burning Study of the Primary Donor Band in Rhodopseudomonas Sphaeroides

    NARCIS (Netherlands)

    Meech, S.R.; Hoff, A.J.

    1985-01-01

    Two coherent spectroscopic methods, accumulated photon echo and population bottleneck hole-burning, have been employed in a study of the decay rate of the primary donor (P) of Rhodopseudomonas sphaeroides at 1.5 K. The decay rate is instrument-limited in the photon-echo experiment, implying a

  7. Crystallization of a flavodoxin involved in nitrogen fixation in Rhodobacter capsulatus

    Energy Technology Data Exchange (ETDEWEB)

    Pérez-Dorado, Inmaculada [Grupo de Cristalografía Macromolecular y Biología Estructural, Instituto de Química-Física Rocasolano, CSIC, Serrano 119, 28006 Madrid (Spain); Bortolotti, Ana; Cortez, Néstor [Instituto de Biología Molecular y Celular de Rosario (Universidad Nacional de Rosario y CONICET), Suipacha 531, S2002LRK Rosario (Argentina); Hermoso, Juan A., E-mail: xjuan@iqfr.csic.es [Grupo de Cristalografía Macromolecular y Biología Estructural, Instituto de Química-Física Rocasolano, CSIC, Serrano 119, 28006 Madrid (Spain)

    2008-05-01

    The flavodoxin NifF from R. capsulatus, a candidate for nitrogenase reduction during nitrogen fixation, has been crystallized using the hanging-drop vapour-diffusion method. Preliminary X-ray data processing at 2.17 Å resolution allowed determination of the crystal system and unit-cell parameters. Flavodoxins are small electron-transfer proteins that contain one molecule of noncovalently bound flavin mononucleotide (FMN). The flavodoxin NifF from the photosynthetic bacterium Rhodobacter capsulatus is reduced by one electron from ferredoxin/flavodoxin:NADP(H) reductase and was postulated to be an electron donor to nitrogenase in vivo. NifF was cloned and overexpressed in Escherichia coli, purified and concentrated for crystallization using the hanging-drop vapour-diffusion method at 291 K. Crystals grew from a mixture of PEG 3350 and PEG 400 at pH 5.5 and belong to the tetragonal space group P4{sub 1}2{sub 1}2, with unit-cell parameters a = b = 66.49, c = 121.32 Å. X-ray data sets have been collected to 2.17 Å resolution.

  8. Long-term biological hydrogen production by agar immobilized Rhodobacter capsulatus in a sequential batch photobioreactor.

    Science.gov (United States)

    Elkahlout, Kamal; Alipour, Siamak; Eroglu, Inci; Gunduz, Ufuk; Yucel, Meral

    2017-04-01

    In this study, agar immobilization technique was employed for biological hydrogen production using Rhodobacter capsulatus DSM 1710 (wild type) and YO3 (hup-mutant) strains in sequential batch process. Different agar and glutamate concentrations were tested with defined nutrient medium. Agar concentration 4% (w/v) and 4 mM glutamate were selected for bacterial immobilization in terms of rate and longevity of hydrogen production. Acetate concentration was increased from 40 to 60-100 and 60 mM gave best results with both bacterial strains immobilized in 4% (w/v) agar. Cell concentration was increased from 2.5 to 5 mg dcw mL -1 agar and it was found that increasing cell concentration of wild-type strain caused decrease in yield and productivity while these parameters improved by increasing cell concentration of mutant strain. Also, the hydrogen production time has extended from 17 days up to 60 days according to the process conditions and parameters. Hydrogen production by immobilized photosynthetic bacteria is a convenient technology for hydrogen production as it enables to produce hydrogen with high organic acid concentrations comparing to suspended cultures. Besides, immobilization increases the stability of the system and allowed sequential batch operation for long-term application.

  9. Field evidence for the potential of Rhodobacter capsulatus as Biofertilizer for flooded rice.

    Science.gov (United States)

    Gamal-Eldin, Hosny; Elbanna, Khaled

    2011-02-01

    In a previous study, we evaluated the effects of inoculating rice plants with the phototrophic purple nonsulfur bacterium Rhodobacter capsulatus (Rc) on growth and yield of rice in pots and lysimeter experiments and the results obtained have been highly encouraging. In this study, we carried out two field experiments: one in the experimental farm of the Faculty of Agriculture, Fayoum University, and the second in a farmer's field in Kafr El-sheikh, to assess the effects of Rc on growth and yield of rice in comparison and in combination with chemical nitrogen fertilizer (CNF) and farmyard manure. The results indicated that both biological and grain yields in all the Rc inoculated treatments were significantly higher than those in the uninoculated corresponding treatments in both fields. With regard to grain yield, the major factor for determining the effectiveness of any agricultural treatment, inoculation with Rc in combination with 50% of the recommended CNF rate gave a grain yield that was statistically equivalent to that obtained with 100% of the recommended CNF rate. These results provide a clear evidence for the potential of Rc as biofertilizer for flooded rice under field conditions.

  10. Transcriptional Profiling of Hydrogen Production Metabolism of Rhodobacter capsulatus under Temperature Stress by Microarray Analysis

    Directory of Open Access Journals (Sweden)

    Muazzez Gürgan

    2015-06-01

    Full Text Available Biohydrogen is a clean and renewable form of hydrogen, which can be produced by photosynthetic bacteria in outdoor large-scale photobioreactors using sunlight. In this study, the transcriptional response of Rhodobacter capsulatus to cold (4 °C and heat (42 °C stress was studied using microarrays. Bacteria were grown in 30/2 acetate/glutamate medium at 30 °C for 48 h under continuous illumination. Then, cold and heat stresses were applied for two and six hours. Growth and hydrogen production were impaired under both stress conditions. Microarray chips for R. capsulatus were custom designed by Affymetrix (GeneChip®. TR_RCH2a520699F. The numbers of significantly changed genes were 328 and 293 out of 3685 genes under cold and heat stress, respectively. Our results indicate that temperature stress greatly affects the hydrogen production metabolisms of R. capsulatus. Specifically, the expression of genes that participate in nitrogen metabolism, photosynthesis and the electron transport system were induced by cold stress, while decreased by heat stress. Heat stress also resulted in down regulation of genes related to cell envelope, transporter and binding proteins. Transcriptome analysis and physiological results were consistent with each other. The results presented here may aid clarification of the genetic mechanisms for hydrogen production in purple non-sulfur (PNS bacteria under temperature stress.

  11. Potential use of thermophilic dark fermentation effluents in photofermentative hydrogen production by Rhodobacter capsulatus

    Energy Technology Data Exchange (ETDEWEB)

    Ozgura, E.; Afsar, N.; Eroglu, I. [Middle East Technical University, Department of Chemical Engineering, 06531 Ankara (Turkey); De Vrije, T.; Claassen, P.A.M. [Wageningen UR, Agrotechnology and Food Sciences Group, Wageningen UR, P.O. Box 17, 6700 AA Wageningen (Netherlands); Yucel, M.; Gunduz, U. [Middle East Technical University, Department of Biology, 06531 Ankara (Turkey)

    2010-12-15

    Biological hydrogen production by a sequential operation of dark and photofermentation is a promising route to produce hydrogen. The possibility of using renewable resources, like biomass and agro-industrial wastes, provides a dual effect of sustainability in biohydrogen production and simultaneous waste removal. In this study, photofermentative hydrogen production on effluents of thermophilic dark fermentations on glucose, potato steam peels (PSP) hydrolysate and molasses was investigated in indoor, batch operated bioreactors. An extreme thermophile Caldicellulosiruptor saccharolyticus was used in the dark fermentation step, and Rhodobacter capsulatus (DSM1710) was used in the photofermentation step. Addition of buffer, Fe and Mo to dark fermentor effluents (DFEs) improved the overall efficiency of hydrogen production. The initial acetate concentration in the DFE needed to be adjusted to 30-40 mM by dilution to increase the yield of hydrogen in batch light-supported fermentations. The thermophilic DFEs are suitable for photofermentative hydrogen production, provided that they are supplemented with buffer and nutrients. The overall hydrogen yield of the two-step fermentations was higher than the yield of single step dark fermentations.

  12. Replacement of sugars to hydrogen production by Rhodobacter capsulatus using dark fermentation effluent as substrate.

    Science.gov (United States)

    Silva, Felipe Thales Moreira; Moreira, Luiza Rojas; de Souza Ferreira, Juliana; Batista, Fabiana Regina Xavier; Cardoso, Vicelma Luiz

    2016-01-01

    Hydrogen is a promising alternative for the increased global energy demand since it has high energy density and is a clean fuel. The aim of this work was to evaluate the photo-fermentation by Rhodobacter capsulatus, using the dark fermentation effluent as substrate. Different systems were tested by changing the type of sugar in the dark fermentation, investigating the influence of supplementing DFE with sugar and adding alternate and periodically lactose and glucose throughout the process. The supplementation of the DFE with sugar resulted in higher H2 productivity and the replacement of the sugars repeatedly during the photo-fermentation process was important to maintain the cell culture active. By controlling the residual amount of sugar, bacteria inhibition was avoided; lactic acid, that was toxic to the biomass, was consumed and the metabolic route of butyric acid production was predominant. Under optimum conditions, the H2 productivity reached 208.40mmolH2/Ld in 52h. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Modelling of hydrogen production in batch cultures of the photosynthetic bacterium Rhodobacter capsulatus

    Energy Technology Data Exchange (ETDEWEB)

    Obeid, Jamila; Magnin, Jean-Pierre [Grenoble Institute of Technology, LEPMI, UMR 5631 (CNRS-INPG-UJF), BP 75, 38402 St Martin d' Heres (France); Flaus, Jean-Marie; Adrot, Olivier [Grenoble Institute of Technology, Laboratoire des sciences pour la conception, l' optimisation et la production, 46, avenue Felix Viallet, 38031 Grenoble (France); Willison, John C. [Laboratoire de Chimie et Biologie des Metaux (UMR 5249 CEA-CNRS-UJF), iRTSV/LCBM, CEA-Grenoble, 38054 Grenoble (France); Zlatev, Roumen [Autonomous University of Baja California, Institute of Engineering, Mexicali, Baja California (Mexico)

    2009-01-15

    The photosynthetic bacterium, Rhodobacter capsulatus, produces hydrogen under nitrogen-limited, anaerobic, photosynthetic culture conditions, using various carbon substrates. In the present study, the relationship between light intensity and hydrogen production has been modelled in order to predict both the rate of hydrogen production and the amount of hydrogen produced at a given time during batch cultures of R. capsulatus. The experimental data were obtained by investigating the effect of different light intensities (6000-50,000 lux) on hydrogen-producing cultures of R. capsulatus grown in a batch photobioreactor, using lactate as carbon and hydrogen source. The rate of hydrogen production increased with increasing light intensity in a manner that was described by a static Baly model, modified to include the square of the light intensity. In agreement with previous studies, the kinetics of substrate utilization and growth of R. capsulatus was represented by the classical Monod or Michaelis-Menten model. When combined with a dynamic Leudekong-Piret model, the amount of hydrogen produced as a function of time was effectively predicted. These results will be useful for the automatization and control of bioprocesses for the photoproduction of hydrogen. (author)

  14. Improving the hydrogen production capacity of Rhodobacter capsulatus by genetically modifying redox balancing pathways

    Energy Technology Data Exchange (ETDEWEB)

    Oeztuerk, Yavuz [TUEBITAK Research Institute for Genetic Engineering and Biotechnology, Gebze Kocaeli (Turkey); Goekce, Abdulmecit [Istanbul Technical Univ. (Turkey). Dept. of Molecular Biology and Genetics; Guergan, Muazzez; Yuecel, Meral [Middle East Technical Univ., Ankara (Turkey). Dept. of Biology

    2010-07-01

    In Rhodobacter capsulatus, balancing the oxidation-reduction potential (redox-balance) is maintained via a number of inter-dependent regulatory mechanisms that enable these organisms to accommodate divergent growth modes. In order to maintain redox homeostasis, this bacterium possesses regulatory mechanisms functioning as electron sinks affecting the oxidation-reduction state of the ubiquinone pool. Under the photoheterotrophic growth conditions with reduced carbon sources, the excess reducing equivalents are primarily consumed via the reduction of CO{sub 2} through the Calvin-Benson-Bassham (CBB) pathway or by the reduction of protons into hydrogen with the use of dinitrogenase enzyme system. In this study, our aim was to develop strategies to funnel the excess reducing equivalents to nitrogenase-dependent hydrogen production by blocking the carbon-fixation pathway. To realize this purpose, CO{sub 2} fixation was blocked by inactivating the Phosphoribulokinase (PRK) of CBB pathway in wild type (MT1131), uptake-hydrogenase (YO3) and cyt cbb{sub 3} oxidase deficient (YO4) strains. The hydrogen production capacity of newly generated strains deficient in the Calvin-Benson-Bassham pathway were analyzed and compared with wild type strains. The results indicated that, the hydrogen production efficiency and capacity of R. capsulatus was further improved by directing the excess reducing equivalents to dinitrogenase-dependent hydrogen production. (orig.)

  15. Crystal structures of the active and alloxanthine-inhibited forms of xanthine dehydrogenase from Rhodobacter capsulatus.

    Science.gov (United States)

    Truglio, James J; Theis, Karsten; Leimkühler, Silke; Rappa, Roberto; Rajagopalan, K V; Kisker, Caroline

    2002-01-01

    Xanthine dehydrogenase (XDH), a complex molybdo/iron-sulfur/flavoprotein, catalyzes the oxidation of hypoxanthine to xanthine followed by oxidation of xanthine to uric acid with concomitant reduction of NAD+. The 2.7 A resolution structure of Rhodobacter capsulatus XDH reveals that the bacterial and bovine XDH have highly similar folds despite differences in subunit composition. The NAD+ binding pocket of the bacterial XDH resembles that of the dehydrogenase form of the bovine enzyme rather than that of the oxidase form, which reduces O(2) instead of NAD+. The drug allopurinol is used to treat XDH-catalyzed uric acid build-up occurring in gout or during cancer chemotherapy. As a hypoxanthine analog, it is oxidized to alloxanthine, which cannot be further oxidized but acts as a tight binding inhibitor of XDH. The 3.0 A resolution structure of the XDH-alloxanthine complex shows direct coordination of alloxanthine to the molybdenum via a nitrogen atom. These results provide a starting point for the rational design of new XDH inhibitors.

  16. Role of XDHC in Molybdenum Cofactor Insertion into Xanthine Dehydrogenase of Rhodobacter capsulatus

    Science.gov (United States)

    Leimkühler, Silke; Klipp, Werner

    1999-01-01

    Rhodobacter capsulatus xanthine dehydrogenase (XDH) is composed of two subunits, XDHA and XDHB. Immediately downstream of xdhB, a third gene was identified, designated xdhC, which is cotranscribed with xdhAB. Interposon mutagenesis revealed that the xdhC gene product is required for XDH activity. However, XDHC is not a subunit of active XDH, which forms an α2β2 heterotetramer in R. capsulatus. It was shown that XDHC neither is a transcriptional regulator for xdh gene expression nor influences XDH stability. To analyze the function of XDHC for XDH in R. capsulatus, inactive XDH was purified from an xdhC mutant strain. Analysis of the molybdenum cofactor content of this enzyme demonstrated that in the absence of XDHC, no molybdopterin cofactor MPT is present in the XDHAB tetramer. In contrast, absorption spectra of inactive XDH isolated from the xdhC mutant revealed the presence of iron-sulfur clusters and flavin adenine dinucleotide, demonstrating that XDHC is not required for the insertion of these cofactors. The absence of MPT from XDH isolated from an xdhC mutant indicates that XDHC either acts as a specific MPT insertase or might be a specific chaperone facilitating the insertion of MPT and/or folding of XDH during or after cofactor insertion. PMID:10217763

  17. The mechanism of assembly and cofactor insertion into Rhodobacter capsulatus xanthine dehydrogenase.

    Science.gov (United States)

    Schumann, Silvia; Saggu, Miguel; Möller, Nadine; Anker, Stefan D; Lendzian, Friedhelm; Hildebrandt, Peter; Leimkühler, Silke

    2008-06-13

    Rhodobacter capsulatus xanthine dehydrogenase (XDH) is a molybdo-flavoprotein that is highly homologous to the homodimeric mammalian xanthine oxidoreductase. However, the bacterial enzyme has an (alphabeta)(2) heterotetrameric structure, and the cofactors were identified to be located on two different polypeptides. We have analyzed the mechanism of cofactor insertion and subunit assembly of R. capsulatus XDH, using engineered subunits with appropriate substitutions in the interfaces. In an (alphabeta) heterodimeric XDH containing the XdhA and XdhB subunits, the molybdenum cofactor (Moco) was shown to be absent, indicating that dimerization of the (alphabeta) subunits has to precede Moco insertion. In an (alphabeta)(2) XDH heterotetramer variant, including only one active Moco-center, the active (alphabeta) site of the chimeric enzyme was shown to be fully active, revealing that the two subunits act independent without cooperativity. Amino acid substitutions at two cysteine residues coordinating FeSI of the two [2Fe-2S] clusters of the enzyme demonstrate that an incomplete assembly of FeSI impairs the formation of the XDH (alphabeta)(2) heterotetramer and, thus, insertion of Moco into the enzyme. The results reveal that the insertion of the different redox centers into R. capsulatus XDH takes place sequentially. Dimerization of two (alphabeta) dimers is necessary for insertion of sulfurated Moco into apo-XDH, the last step of XDH maturation.

  18. Melting ice, growing trade?

    National Research Council Canada - National Science Library

    Sami Bensassi; Julienne C. Stroeve; Inmaculada Martínez-Zarzoso; Andrew P. Barrett

    2016-01-01

    Abstract Large reductions in Arctic sea ice, most notably in summer, coupled with growing interest in Arctic shipping and resource exploitation have renewed interest in the economic potential of the Northern Sea Route (NSR...

  19. Zinc biosorption by the purple non-sulfur bacterium Rhodobacter capsulatus.

    Science.gov (United States)

    Magnin, Jean-Pierre; Gondrexon, Nicolas; Willison, John C

    2014-12-01

    This paper presents the first report providing information on the zinc (Zn) biosorption potentialities of the purple non-sulfur bacterium Rhodobacter capsulatus. The effects of various biological, physical, and chemical parameters on Zn biosorption were studied in both the wild-type strain B10 and a strain, RC220, lacking the endogenous plasmid. At an initial Zn concentration of 10 mg·L(-1), the Zn biosorption capacity at pH 7 for bacterial biomass grown in synthetic medium containing lactate as carbon source was 17 and 16 mg Zn·(g dry mass)(-1) for strains B10 and RC220, respectively. Equilibrium was achieved in a contact time of 30-120 min, depending on the initial Zn concentration. Zn sorption by live biomass was modelled, at equilibrium, according to the Redlich-Peterson and Langmuir isotherms, in the range of 1-600 mg Zn·L(-1). The wild-type strain showed a maximal Zn uptake capacity (Qm) of 164 ± 8 mg·(g dry mass)(-1) and an equilibrium constant (Kads) of 0.017 ± 0.00085 L·(mg Zn)(-1), compared with values of 73.9 mg·(g dry mass)(-1) and 0.361 L·mg(-1) for the strain lacking the endogenous plasmid. The Qm value observed for R. capsulatus B10 is one of the highest reported in the literature, suggesting that this strain may be useful for Zn bioremediation. The lower Qm value and higher equilibrium constant observed for strain RC220 suggest that the endogenous plasmid confers an enhanced biosorption capacity in this bacterium, although no genetic determinants for Zn resistance appear to be located on the plasmid, and possible explanations for this are discussed.

  20. Optimizing multi-step B-side charge separation in photosynthetic reaction centers from Rhodobacter capsulatus

    Energy Technology Data Exchange (ETDEWEB)

    Faries, Kaitlyn M. [Washington Univ., St. Louis, MO (United States); Kressel, Lucas L. [Argonne National Lab. (ANL), Argonne, IL (United States); Dylla, Nicholas P. [Argonne National Lab. (ANL), Argonne, IL (United States); Wander, Marc J. [Argonne National Lab. (ANL), Argonne, IL (United States); Hanson, Deborah K. [Argonne National Lab. (ANL), Argonne, IL (United States); Holten, Dewey [Washington Univ., St. Louis, MO (United States); Laible, Philip D. [Argonne National Lab. (ANL), Argonne, IL (United States); Kirmaier, Christine [Washington Univ., St. Louis, MO (United States)

    2016-02-01

    Using high-throughput methods for mutagenesis, protein isolation and charge-separation functionality, we have assayed 40 Rhodobacter capsulatus reaction center (RC) mutants for their P+ QB- yield (P is a dimer of bacteriochlorophylls and Q is a ubiquinone) as produced using the normally inactive B-side cofactors BB and HB (where B is a bacteriochlorophyll and H is a bacteriopheophytin). Two sets of mutants explore all possible residues at M131 (M polypeptide, native residue Val near HB) in tandem with either a fixed His or a fixed Asn at L181 (L polypeptide, native residue Phe near BB). A third set of mutants explores all possible residues at L181 with a fixed Glu at M131 that can form a hydrogen bond to HB. For each set of mutants, the results of a rapid millisecond screening assay that probes the yield of P+ QB- are compared among that set and to the other mutants reported here or previously. For a subset of eight mutants, the rate constants and yields of the individual B-side electron transfer processes are determined via transient absorption measurements spanning 100 fs to 50 μs. The resulting ranking of mutants for their yield of P+ QB- from ultrafast experiments is in good agreement with that obtained from the millisecond screening assay, further validating the efficient, high-throughput screen for B-side transmembrane charge separation. Results from mutants that individually show progress toward optimization of P+ HB- → P+ QB- electron transfer or initial P* → P+ HB- conversion highlight unmet challenges of optimizing both processes simultaneously.

  1. Coordinated, long-range, solid substrate movement of the purple photosynthetic bacterium Rhodobacter capsulatus.

    Directory of Open Access Journals (Sweden)

    Kristopher John Shelswell

    Full Text Available The long-range movement of Rhodobacter capsulatus cells in the glass-agar interstitial region of borosilicate Petri plates was found to be due to a subset of the cells inoculated into plates. The macroscopic appearance of plates indicated that a small group of cells moved in a coordinated manner to form a visible satellite cluster of cells. Satellite clusters were initially separated from the point of inoculation by the absence of visible cell density, but after 20 to 24 hours this space was colonized by cells apparently shed from a group of cells moving away from the point of inoculation. Cell movements consisted of flagellum-independent and flagellum-dependent motility contributions. Flagellum-independent movement occurred at an early stage, such that satellite clusters formed after 12 to 24 hours. Subsequently, after 24 to 32 hours, a flagellum-dependent dispersal of cells became visible, extending laterally outward from a line of flagellum-independent motility. These modes of taxis were found in several environmental isolates and in a variety of mutants, including a strain deficient in the production of the R. capsulatus acyl-homoserine lactone quorum-sensing signal. Although there was great variability in the direction of movement in illuminated plates, cells were predisposed to move toward broad spectrum white light. This predisposition was increased by the use of square plates, and a statistical analysis indicated that R. capsulatus is capable of genuine phototaxis. Therefore, the variability in the direction of cell movement was attributed to optical effects on light waves passing through the plate material and agar medium.

  2. Molecular genetic and molecular evolutionary studies on the bacteriochlorophyll synthesis genes of Rhodobacter capsulatus

    Energy Technology Data Exchange (ETDEWEB)

    Burke-Agueero, Donald H. [Univ. of California, Berkeley, CA (United States)

    1992-08-01

    Rhodobacter capsulatus, purple bacterium capable of either aerobic or photosynthetic growth, has proven to be very useful in genetic studies of photosynthesis. Forty-four genes clustered together within a 46 kilobase region are required to establish photosynthetic ability in R. capsulatus. Approximately twenty of these genes are involved in bacteriochlorophyll synthesis of which eight ``bch`` genes are the subject of this thesis. Six of these genes were found to code for the two ring reductases. The first converts protochlorophyllide (PChlide) into a chlorin, the immediate precursor to chlorophyll a, and then into a bacteriochlorin. Each reductase is shown to be made up of three subunits. PChlide reductase is coded by the genes bchN, bchB, and bchL. Proteins with amino acid sequences markedly similar to those of bchN and bchL have been shown in other organisms to be required for chlorophyll synthesis; hence, their designation as chlN and chlB. A third chloroplast-encoded gene of heretofore unknown function shares amino acid identities with bchB and is probably the third subunit of the plant PChlide reductase. The bchA locus, which encodes the chlorin reductase, is found to be made up of three separate, translationally coupled genes, referred to as bchX, bchY, and bchZ. Amino acid similarities between bchX, bchL, and the nitrogenase reductase protein nifH suggest that all three classes of proteins share certain three-dimensional structural features, including elements that are central to the enzymatic mechanism of nifH. PChlide reductase and chlorin reductase are clearly derived from a common ancestor. Several lines of analysis suggests the ancestor of both enzyme systems reduced PChlide twice to produce bacteriochlorophyll supporting the concept bacteriochlorophyll as the ancestral reaction center pigment.

  3. Molecular genetic and molecular evolutionary studies on the bacteriochlorophyll synthesis genes of Rhodobacter capsulatus

    Energy Technology Data Exchange (ETDEWEB)

    Burke-Agueero, D.H.

    1992-08-01

    Rhodobacter capsulatus, purple bacterium capable of either aerobic or photosynthetic growth, has proven to be very useful in genetic studies of photosynthesis. Forty-four genes clustered together within a 46 kilobase region are required to establish photosynthetic ability in R. capsulatus. Approximately twenty of these genes are involved in bacteriochlorophyll synthesis of which eight bch'' genes are the subject of this thesis. Six of these genes were found to code for the two ring reductases. The first converts protochlorophyllide (PChlide) into a chlorin, the immediate precursor to chlorophyll a, and then into a bacteriochlorin. Each reductase is shown to be made up of three subunits. PChlide reductase is coded by the genes bchN, bchB, and bchL. Proteins with amino acid sequences markedly similar to those of bchN and bchL have been shown in other organisms to be required for chlorophyll synthesis; hence, their designation as chlN and chlB. A third chloroplast-encoded gene of heretofore unknown function shares amino acid identities with bchB and is probably the third subunit of the plant PChlide reductase. The bchA locus, which encodes the chlorin reductase, is found to be made up of three separate, translationally coupled genes, referred to as bchX, bchY, and bchZ. Amino acid similarities between bchX, bchL, and the nitrogenase reductase protein nifH suggest that all three classes of proteins share certain three-dimensional structural features, including elements that are central to the enzymatic mechanism of nifH. PChlide reductase and chlorin reductase are clearly derived from a common ancestor. Several lines of analysis suggests the ancestor of both enzyme systems reduced PChlide twice to produce bacteriochlorophyll supporting the concept bacteriochlorophyll as the ancestral reaction center pigment.

  4. Rhodobacter capsulatus gains a competitive advantage from respiratory nitrate reduction during light-dark transitions.

    Science.gov (United States)

    Ellington, M J K; Richardson, D J; Ferguson, S J

    2003-04-01

    Rhodobacter capsulatus N22DNAR(+) possesses a periplasmic nitrate reductase and is capable of reducing nitrate to nitrite under anaerobic conditions. In the absence of light this ability cannot support chemoheterotrophic growth in batch cultures. This study investigated the effect of nitrate reduction on the growth of R. capsulatus N22DNAR(+) during multiple light-dark cycles of anaerobic photoheterotrophic/dark chemoheterotrophic growth conditions in carbon-limited continuous cultures. The reduction of nitrate did not affect the photoheterotrophic growth yield of R. capsulatus N22DNAR(+). After a transition from photoheterotrophic to dark chemoheterotrophic growth conditions, the reduction of nitrate slowed the initial washout of a R. capsulatus N22DNAR(+) culture. Towards the end of a period of darkness nitrate-reducing cultures maintained higher viable cell counts than non-nitrate-reducing cultures. During light-dark cycling of a mixed culture, the strain able to reduce nitrate (N22DNAR(+)) outcompeted the strain which was unable to reduce nitrate (N22). The evidence indicates that the periplasmic nitrate reductase activity supports slow growth that retards the washout of a culture during anaerobic chemoheterotrophic conditions, and provides a protonmotive force for cell maintenance during the dark period before reillumination. This translates into a selective advantage during repeated light-dark cycles, such that in mixed culture N22DNAR(+) outcompetes N22. Exposure to light-dark cycles will be a common feature for R. capsulatus in its natural habitats, and this study shows that nitrate respiration may provide a selective advantage under such conditions.

  5. Mechanism of Substrate and Inhibitor Binding of Rhodobacter Capsulatus Xanthine Dehydrogenase

    Energy Technology Data Exchange (ETDEWEB)

    Dietzel, U.; Kuper, J; Doebbler, J; Schulte, A; Truglio, J; Leimkuhler, S; Kisker, C

    2009-01-01

    Rhodobacter capsulatus xanthine dehydrogenase (XDH) is an (ae)2 heterotetrameric cytoplasmic enzyme that resembles eukaryotic xanthine oxidoreductases in respect to both amino acid sequence and structural fold. To obtain a detailed understanding of the mechanism of substrate and inhibitor binding at the active site, we solved crystal structures of R. capsulatus XDH in the presence of its substrates hypoxanthine, xanthine, and the inhibitor pterin-6-aldehyde using either the inactive desulfo form of the enzyme or an active site mutant (EB232Q) to prevent substrate turnover. The hypoxanthine- and xanthine-bound structures reveal the orientation of both substrates at the active site and show the importance of residue GluB-232 for substrate positioning. The oxygen atom at the C-6 position of both substrates is oriented toward ArgB-310 in the active site. Thus the substrates bind in an orientation opposite to the one seen in the structure of the reduced enzyme with the inhibitor oxypurinol. The tightness of the substrates in the active site suggests that the intermediate products must exit the binding pocket to allow first the attack of the C-2, followed by oxidation of the C-8 atom to form the final product uric acid. Structural studies of pterin-6-aldehyde, a potent inhibitor of R. capsulatus XDH, contribute further to the understanding of the relative positioning of inhibitors and substrates in the binding pocket. Steady state kinetics reveal a competitive inhibition pattern with a Ki of 103.57 {+-} 18.96 nm for pterin-6-aldehyde.

  6. Exploration of the hydrogen producing potential of Rhodobacter capsulatus chemostat cultures: The application of deceleration-stat and gradient-stat methodology

    NARCIS (Netherlands)

    Hoekema, S.; Breukelen, van F.R.; Janssen, M.G.J.; Tramper, J.; Wijffels, R.H.

    2009-01-01

    In this work, the dependency of the volumetric hydrogen production rate of ammonium-limited Rhodobacter capsulatus chemostat cultures on their imposed biomass concentration and dilution rate was investigated. A deceleration-stat experiment was performed by lowering the dilution rate from 1.0 d-1 to

  7. Growing Plants and Minds

    Science.gov (United States)

    Presser, Ashley Lewis; Kamdar, Danae; Vidiksis, Regan; Goldstein, Marion; Dominguez, Ximena; Orr, Jillian

    2017-01-01

    Many preschool classrooms explore plant growth. However, because many plants take a long time to grow, it is often hard to facilitate engagement in some practices (i.e., since change is typically not observable from one day to another, children often forget their prior predictions or cannot recall what plants looked like days or weeks earlier).…

  8. Growing Up with "1984."

    Science.gov (United States)

    Franza, August

    1983-01-01

    Relates changing student reaction to George Orwell's "1984" over 20 years of teaching. Finds present high school students' acceptance of Orwell's bleak world vision both a sign of student honesty and a frightening indication of the growing reality of the book. (MM)

  9. Growing through Literature.

    Science.gov (United States)

    Thomas, Barbara J.

    "Growing through Literature" is a curriculum using Joan M. and Erik H. Erikson's theory of the Life Cycle as a structure for selecting and teaching literature to inner-city high school students at Brighton High School in Massachusetts. The program consists of four component parts: Journals, Selected Stories, Discussion, and…

  10. Growing Old in Exile

    DEFF Research Database (Denmark)

    Liversage, Anika; Mirdal, Gretty Mizrahi

    2017-01-01

    Some studies on immigrants and ageing focus on the question of return; others focus on how immigrants, who grow old in their countries of destination, ‘age in place’, including whether they turn to their children or to public host country provisions for care and support. However, the issues of re...

  11. Imaging of solid tumor using near-infrared emitting purple bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Sung Min; Min, Jung Joon; Kim, Sun A; Choy, Hyon E.; Bom, Hee Seung [Chonnam National University Medical School, Gwangju (Korea, Republic of)

    2005-07-01

    Rhodobacter sphaeroides 2.4.1 is {alpha}-3 purple nonsulfur eubacterium with an extensive metabolism. Under anaerobic conditions, it is able to grow by photosynthesis, respiration and fermentation. When grown photosynthetically, it uses wavelengths of light in the near-infrared and contains a reaction center that is the peripheral light-harvesting (LH2) complex. These molecules absorb and emit near-infrared light. Using this near-infrared fluorescent bacterial we investigated its targeting capacity of solid tumor in small animals. R. sphaeroides 2.4.1 strains were cultured in sistrons minimal medium A (SIS) at 32 C. Xenograft tumor model has been established by subcutaneous injection of CT26 mouse colon cancer cell line. 1X10 8 Rhodobacter sphaeroides cells suspended in 100 ul of PBS were injected via tail vein with 1-cc insulin syringe into tumor bearing mouse. In vivo fluorescence imaging has been done after 20 min to 30 days of purple bacteria using indocyanine (ICG) emission filter (Em=810{approx}835 nm). Near-infrared imaging signal from Rhodobacter sphaeroides was initially detected at liver for 3 days but at the necrotic region of tumor mass thereafter. Total photon flux measured 5.5X10{sup 8} (p/s/cm{sup 2}/sr) at Day 1. Also it was increased to 7.8X10{sup 8} (p/s/cm{sup 2}/sr) at 12 day. One of important characteristic is that the signal appeared only at central necrosis area. It has been monitored for 36 day. We successfully imaged cancer with near-infrared fluorescence bacteria. Our result indicate that near-infrared fluorescence purple bacteria are able to be used to monitor bacterial trafficking in living tumor models.

  12. Growing unculturable bacteria.

    Science.gov (United States)

    Stewart, Eric J

    2012-08-01

    The bacteria that can be grown in the laboratory are only a small fraction of the total diversity that exists in nature. At all levels of bacterial phylogeny, uncultured clades that do not grow on standard media are playing critical roles in cycling carbon, nitrogen, and other elements, synthesizing novel natural products, and impacting the surrounding organisms and environment. While molecular techniques, such as metagenomic sequencing, can provide some information independent of our ability to culture these organisms, it is essentially impossible to learn new gene and pathway functions from pure sequence data. A true understanding of the physiology of these bacteria and their roles in ecology, host health, and natural product production requires their cultivation in the laboratory. Recent advances in growing these species include coculture with other bacteria, recreating the environment in the laboratory, and combining these approaches with microcultivation technology to increase throughput and access rare species. These studies are unraveling the molecular mechanisms of unculturability and are identifying growth factors that promote the growth of previously unculturable organisms. This minireview summarizes the recent discoveries in this area and discusses the potential future of the field.

  13. Growing for different ends.

    Science.gov (United States)

    Catts, Oron; Zurr, Ionat

    2014-11-01

    Tissue engineering and regenerative biology are usually discussed in relation to biomedical research and applications. However, hand in hand with developments of this field in the biomedical context, other approaches and uses for non-medical ends have been explored. There is a growing interest in exploring spin off tissue engineering and regenerative biology technologies in areas such as consumer products, art and design. This paper outlines developments regarding in vitro meat and leather, actuators and bio-mechanic interfaces, speculative design and contemporary artistic practices. The authors draw on their extensive experience of using tissue engineering for non-medical ends to speculate about what lead to these applications and their possible future development and uses. Avoiding utopian and dystopian postures and using the notion of the contestable, this paper also mentions some philosophical and ethical consideration stemming from the use of non-medical approaches to tissue constructs. This article is part of a directed issue entitled: Regenerative Medicine: the challenge of translation. Copyright © 2014. Published by Elsevier Ltd.

  14. NCBI nr-aa BLAST: CBRC-DYAK-06-0005 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DYAK-06-0005 ref|YP_001170129.1| two component transcriptional regulator, winged... helix family [Rhodobacter sphaeroides ATCC 17025] gb|ABP72824.1| two component transcriptional regulator, winged

  15. BIOTECHNOLOGY IN FRUIT GROWING

    Directory of Open Access Journals (Sweden)

    Z. Jurković

    2008-09-01

    Full Text Available Research studies in the area of biotechnologies in fruit growing started at the Agricultural Institute Osijek in 2006 with the establishment of the first experimental in vitro laboratory for micropropagation. The laboratory started an active research related to the Project "Biotechnological methods in fruit tree identification, selection and propagation" Project is part of program "Preservation and revitalization of grape and fruit autochthonous cultivars". The goal of this research is to determine genetic differences between autochthonous and introduced cultivars of cherry as well as cultivars and types of sour cherry, to find and optimize a method for fast recovery of clonal material. A great number of cherry cultivars and types within the population of cv. Oblacinska sour cherry exists in Croatia. A survey with the purpose of selecting autochthonous cultivars for further selection has been done in previous research. Differences have been found in a number of important agronomic traits within the populations of cv. Oblačinska sour cherry. Autochthonous cherry cultivars are suspected to be synonyms of known old cultivars which were introduced randomly and have been naturalized under a local name. Identification and description of cultivars and types of fruits is based on special visible properties which were measurable or notable. In this approach difficulties arise from the effect of non-genetic factors on expression of certain traits. Genetic-physiological problem of S allele autoincompatibility exists within cherry cultivars. Therefore it is necessary to put different cultivars in the plantation to pollinate each other. Apart form the fast and certain sort identification independent of environmental factors, biotechnological methods based on PCR enable faster virus detection compared with classical serologic methods and indexing and cover a wider range of plant pathogens including those undetectable by other methods. Thermotherapy and

  16. Growing Galaxies Gently

    Science.gov (United States)

    2010-10-01

    New observations from ESO's Very Large Telescope have, for the first time, provided direct evidence that young galaxies can grow by sucking in the cool gas around them and using it as fuel for the formation of many new stars. In the first few billion years after the Big Bang the mass of a typical galaxy increased dramatically and understanding why this happened is one of the hottest problems in modern astrophysics. The results appear in the 14 October issue of the journal Nature. The first galaxies formed well before the Universe was one billion years old and were much smaller than the giant systems - including the Milky Way - that we see today. So somehow the average galaxy size has increased as the Universe has evolved. Galaxies often collide and then merge to form larger systems and this process is certainly an important growth mechanism. However, an additional, gentler way has been proposed. A European team of astronomers has used ESO's Very Large Telescope to test this very different idea - that young galaxies can also grow by sucking in cool streams of the hydrogen and helium gas that filled the early Universe and forming new stars from this primitive material. Just as a commercial company can expand either by merging with other companies, or by hiring more staff, young galaxies could perhaps also grow in two different ways - by merging with other galaxies or by accreting material. The team leader, Giovanni Cresci (Osservatorio Astrofisico di Arcetri) says: "The new results from the VLT are the first direct evidence that the accretion of pristine gas really happened and was enough to fuel vigorous star formation and the growth of massive galaxies in the young Universe." The discovery will have a major impact on our understanding of the evolution of the Universe from the Big Bang to the present day. Theories of galaxy formation and evolution may have to be re-written. The group began by selecting three very distant galaxies to see if they could find evidence

  17. Iron metabolism in Rhodobacter capsulatus. Characterisation of bacterioferritin and formation of non-haem iron particles in intact cells.

    Science.gov (United States)

    Ringeling, P L; Davy, S L; Monkara, F A; Hunt, C; Dickson, D P; McEwan, A G; Moore, G R

    1994-08-01

    The water-soluble cytochrome b557 from the photosynthetic bacterium Rhodobacter capsulatus was purified and shown to have the properties of the iron-storage protein bacterioferritin. The molecular mass of R. capsulatus bacterioferritin is 428 kDa and it is composed of a single type of 18-kDa subunit. The N-terminal amino acid sequence of the bacterioferritin subunit shows 70% identity to the sequence of bacterioferritin subunits from Escherichia coli, Nitrobacter winogradskyi, Azotobacter vinelandii and Synechocystis PCC 6803. The absorbance spectrum of reduced bacterioferritin shows absorbance maxima at 557 nm (alpha band), 526 nm (beta band) and 417 nm (Soret band) from the six haem groups/molecule. Antibody assays reveal that bacterioferritin is located in the cytoplasm of R. capsulatus, and its levels stay relatively constant during batch growth under aerobic conditions when the iron concentration in the medium is kept constant. Iron deficiency leads to a decrease in bacterioferritin and iron overload leads to an increase. Bacterioferritin from R. capsulatus has an amorphous iron-oxide core with a high phosphate content (900-1000 Fe atoms and approximately 600 phosphates/bacterioferritin molecule). Mössbauer spectroscopy indicates that in both aerobically and anaerobically (phototrophically) grown cells bacterioferritin with an Fe3+ core is formed, suggesting that iron-core formation in vivo may not always require molecular oxygen.

  18. Vitamin B12 regulates photosystem gene expression via the CrtJ antirepressor AerR in Rhodobacter capsulatus

    Science.gov (United States)

    Cheng, Zhuo; Li, Keran; Hammad, Loubna A.; Karty, Jonathan A.; Bauer, Carl E.

    2014-01-01

    Summary The tetrapyrroles heme, bacteriochlorophyll and cobalamin (B12) exhibit a complex interrelationship regarding their synthesis. In this study, we demonstrate that AerR functions as an antirepressor of the tetrapyrrole regulator CrtJ. We show that purified AerR contains B12 that is bound to a conserved histidine (His145) in AerR. The interaction of AerR to CrtJ was further demonstrated in vitro by pull down experiments using AerR as bait and quantified using microscale thermophoresis. DNase I DNA footprint assays show that AerR containing B12 inhibits CrtJ binding to the bchC promoter. We further show that bchC expression is greatly repressed in a B12 auxotroph of Rhodobacter capsulatus and that B12 regulation of gene expression is mediated by AerR’s ability to function as an antirepressor of CrtJ. This study thus provides a mechanism for how the essential tetrapyrrole, cobalamin controls the synthesis of bacteriochlorophyll, an essential component of the photosystem. PMID:24329562

  19. Demonstration and optimization of sequential microaerobic dark- and photo-fermentation biohydrogen production by immobilized Rhodobacter capsulatus JP91.

    Science.gov (United States)

    Sağır, Emrah; Yucel, Meral; Hallenbeck, Patrick C

    2017-11-09

    Hydrogen generation from complex substrates composed of simple sugars has the potential to mitigate future worldwide energy demand. The biohydrogen potential of a sequential microaerobic dark- and photo-fermentative system was investigated using immobilized Rhodobacter capsulatus JP91. Biological hydrogen production from glucose was carried out using a batch process and a bench-scale bioreactor. Response surface methodology with a Box-Behnken design was employed to optimize key parameters such as inoculum concentration, oxygen concentration, and glucose concentration. The maximum hydrogen production (21 ± 0.25 mmol H2/L) and yield (7.8 ± 0.1 mol H2/mol glucose) were obtained at 6 mM glucose, 4.5% oxygen and 62.5 v/v% inoculum concentration, demonstrating the feasibility of enhanced hydrogen production by immobilized R. capsulatus JP91 in a sequential system. This is the first time that a sequential process using an immobilized system has been described. This system also achieved the highest hydrogen yield obtained by an immobilized system so far. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Manipulating the Energetics and Rates of Electron Transfer in Rhodobacter capsulatus Reaction Centers with Asymmetric Pigment Content.

    Science.gov (United States)

    Faries, Kaitlyn M; Dylla, Nicholas P; Hanson, Deborah K; Holten, Dewey; Laible, Philip D; Kirmaier, Christine

    2017-07-27

    Seemingly redundant parallel pathways for electron transfer (ET), composed of identical sets of cofactors, are a cornerstone feature of photosynthetic reaction centers (RCs) involved in light-energy conversion. In native bacterial RCs, both A and B branches house one bacteriochlorophyll (BChl) and one bacteriopheophytin (BPh), but the A branch is used exclusively. Described herein are the results obtained for two Rhodobacter capsulatus RCs with an unnaturally high degree of cofactor asymmetry, two BPh on the RC's B side and two BChl on the A side. These pigment changes derive, respectively, from the His(M180)Leu mutation [a BPh (Φ B ) replaces the B-side BChl (B B )], and the Leu(M212)His mutation [a BChl (β A ) replaces the A-side BPh (H A )]. Additionally, Tyr(M208)Phe was employed to disfavor ET to the A branch; in one mutant, Val(M131)Glu creates a hydrogen bond to H B to enhance ET to H B . In both Φ B mutants, the decay kinetics of the excited primary ET donor (P*) resolve three populations with lifetimes of ∼9 ps (50-60%), ∼40 ps (10-20%), and ∼200 ps (20-30%), with P + Φ B - formed predominantly from the 9 ps fraction. The 50-60% yield of P + Φ B - is the highest yet observed for a Φ B -containing RC. The results provide insight into factors needed for efficient multistep ET.

  1. Continuous Cultivation of Photosynthetic Bacteria for Fatty Acids Production

    DEFF Research Database (Denmark)

    Kim, Dong-Hoon; Lee, Ji-Hye; Hwang, Yuhoon

    2013-01-01

    In the present work, we introduced a novel approach for microbial fatty acids (FA) production. Photosynthetic bacteria, Rhodobacter sphaeroides KD131, were cultivated in a continuous-flow, stirred-tank reactor (CFSTR) at various substrate (lactate) concentrations.At hydraulic retention time (HRT) 4....... sphaeroides was around 35% of dry cell weight, mainly composed of vaccenic acid (C18:1, omega-7)....

  2. Identification of a predicted partner-switching system that affects production of the gene transfer agent RcGTA and stationary phase viability in Rhodobacter capsulatus

    OpenAIRE

    Mercer, Ryan G; Lang, Andrew S.

    2014-01-01

    Background Production of the gene transfer agent RcGTA in the α-proteobacterium Rhodobacter capsulatus is dependent upon the response regulator protein CtrA. Loss of this regulator has widespread effects on transcription in R. capsulatus, including the dysregulation of numerous genes encoding other predicted regulators. This includes a set of putative components of a partner-switching signaling pathway with sequence homology to the σ-regulating proteins RsbV, RsbW, and RsbY that have been ext...

  3. The photosynthetic bacteria Rhodobacter capsulatus and Synechocystis sp. PCC 6803 as new hosts for cyclic plant triterpene biosynthesis.

    Directory of Open Access Journals (Sweden)

    Anita Loeschcke

    Full Text Available Cyclic triterpenes constitute one of the most diverse groups of plant natural products. Besides the intriguing biochemistry of their biosynthetic pathways, plant triterpenes exhibit versatile bioactivities, including antimicrobial effects against plant and human pathogens. While prokaryotes have been extensively used for the heterologous production of other classes of terpenes, the synthesis of cyclic triterpenes, which inherently includes the two-step catalytic formation of the universal linear precursor 2,3-oxidosqualene, is still a major challenge. We thus explored the suitability of the metabolically versatile photosynthetic α-proteobacterium Rhodobacter capsulatus SB1003 and cyanobacterium Synechocystis sp. PCC 6803 as alternative hosts for biosynthesis of cyclic plant triterpenes. Therefore, 2,3-oxidosqualene production was implemented and subsequently combined with different cyclization reactions catalyzed by the representative oxidosqualene cyclases CAS1 (cycloartenol synthase, LUP1 (lupeol synthase, THAS1 (thalianol synthase and MRN1 (marneral synthase derived from model plant Arabidopsis thaliana. While successful accumulation of 2,3-oxidosqualene could be detected by LC-MS analysis in both hosts, cyclase expression resulted in differential production profiles. CAS1 catalyzed conversion to only cycloartenol, but expression of LUP1 yielded lupeol and a triterpenoid matching an oxidation product of lupeol, in both hosts. In contrast, THAS1 expression did not lead to cyclic product formation in either host, whereas MRN1-dependent production of marnerol and hydroxymarnerol was observed in Synechocystis but not in R. capsulatus. Our findings thus indicate that 2,3-oxidosqualene cyclization in heterologous phototrophic bacteria is basically feasible but efficient conversion depends on both the respective cyclase enzyme and individual host properties. Therefore, photosynthetic α-proteo- and cyanobacteria are promising alternative candidates

  4. Dietary Effect of Selenium-enriched Radish Sprouts, Vitamin E, and Rhodobacter capsulatus on Hypocholesterolemia and Immunity of Broiler

    Directory of Open Access Journals (Sweden)

    Tsujii H

    2017-06-01

    Full Text Available The study was designed to investigate the effects of dietary Selenium-enriched radish sprouts (Se-RS, Vitamin E (Vit E, and Rhodobacter capsulatus (RC on immunity, cholesterol concentration, and fatty acid composition in broiler meat. A total of 100 two-week-old male broiler chicks were randomly assigned into five dietary groups: I Control; II Se-RS (5 μg/kg Se-RS; III Se-RS+RC (5 μg/kg Se-RS + 0.2 g/kg RC; IV Se-RS+Vit E (5 μg/kg Se-RS + 50 mg/kg Vit E and V Se-RS+RC+Vit E (5 μg/kg Se-RS + 0.2 g/kg RC + 50 mg/kg Vit E. Diets and clean drinking water were offered ad libitum. After the end of 3-wk of feeding period, serum cholesterol and triglycerides concentrations were lower (P < 0.05 in broilers fed Se-RS + RC + Vit E supplemented diet compared to the control diet. At the end of the 6-wk feeding period, birds fed the Se-RS+RC+Vit E diet significantly (P < 0.05 reduced cholesterol and triglycerides concentrations and improved the ratio of unsaturated fatty acids to saturated fatty acids in broiler meat. The highest (P < 0.05 number of leukocytes was observed in broilers fed Se-RS+RC+Vit E supplemented diet. Foot web index and weights of spleen, bursa, and thymus were significantly (P < 0.05 higher in birds fed Se-RS+RC+Vit E compared to the control diet. Our findings suggest that there are dual benefits of supplementing broiler diets with Se-RS+RC+Vit E because of improvements in the bird’s immunity and meat quality that is important for health conscious consumers.

  5. Transfer of the molybdenum cofactor synthesized by Rhodobacter capsulatus MoeA to XdhC and MobA.

    Science.gov (United States)

    Neumann, Meina; Stöcklein, Walter; Leimkühler, Silke

    2007-09-28

    The molybdenum cofactor (Moco) exists in different variants in the cell and can be directly inserted into molybdoenzymes utilizing the molybdopterin (MPT) form of Moco. In bacteria such as Rhodobacter capsulatus and Escherichia coli, MPT is further modified by attachment of a GMP nucleotide, forming MPT guanine dinucleotide (MGD). In this work, we analyzed the distribution and targeting of different forms of Moco to their respective user enzymes by proteins that bind Moco and are involved in its further modification. The R. capsulatus proteins MogA, MoeA, MobA, and XdhC were purified, and their specific interactions were analyzed. Interactions between the protein pairs MogA-MoeA, MoeA-XdhC, MoeA-MobA, and XdhC-MobA were identified by surface plasmon resonance measurements. In addition, the transfer of Moco produced by the MogA-MoeA complex to XdhC was investigated. A direct competition of MobA and XdhC for Moco binding was determined. In vitro analyses showed that XdhC bound to MobA, prevented the binding of Moco to MobA, and thereby inhibited MGD biosynthesis. The data were confirmed by in vivo studies in R. capsulatus cells showing that overproduction of XdhC resulted in a 50% decrease in the activity of bis-MGD-containing Me(2)SO reductase. We propose that, in bacteria, the distribution of Moco in the cell and targeting to the respective user enzymes are accomplished by specific proteins involved in Moco binding and modification.

  6. Growing Concerns With Workplace Incivility.

    Science.gov (United States)

    Collins, Natasha Renee; Rogers, Bonnie

    2017-11-01

    Workplace incivility (WPI) is a growing issue across all public and private sectors. Occupational and environmental health nurses can educate employees and management about WPI, its risk factors and characteristics, and ways to reduce incidents of WPI.

  7. Growing Oppression, Growing Resistance : LGBT Activism and Europeanisation in Macedonia

    NARCIS (Netherlands)

    Miškovska Kajevska, A.; Bilić, B.

    2016-01-01

    This chapter provides one of the first socio-historical overviews of the LGBT groups in Macedonia and argues that an important impetus for the proliferation of LGBT activities has been the growing state-endorsed homophobia starting from 2008. The homophobic rhetoric of the ruling parties was clearly

  8. Exploring Classroom Hydroponics. Growing Ideas.

    Science.gov (United States)

    National Gardening Association, Burlington, VT.

    Growing Ideas, the National Gardening Association's series for elementary, middle, and junior high school educators, helps teachers engage students in using plants and gardens as contexts for developing a deeper, richer understanding of the world around them. This volume's focus is on hydroponics. It presents basic hydroponics information along…

  9. Growing Patterns: Seeing beyond Counting

    Science.gov (United States)

    Markworth, Kimberly A.

    2012-01-01

    Over the past two decades, mathematical patterns have been acknowledged as important early components of children's development of algebraic reasoning (NCTM 2000). In particular, growing patterns have attracted significant attention as a context that helps students develop an understanding of functional relationships (Lee and Freiman 2006; Moss et…

  10. Organization of growing random networks

    Energy Technology Data Exchange (ETDEWEB)

    Krapivsky, P. L.; Redner, S.

    2001-06-01

    The organizational development of growing random networks is investigated. These growing networks are built by adding nodes successively, and linking each to an earlier node of degree k with an attachment probability A{sub k}. When A{sub k} grows more slowly than linearly with k, the number of nodes with k links, N{sub k}(t), decays faster than a power law in k, while for A{sub k} growing faster than linearly in k, a single node emerges which connects to nearly all other nodes. When A{sub k} is asymptotically linear, N{sub k}(t){similar_to}tk{sup {minus}{nu}}, with {nu} dependent on details of the attachment probability, but in the range 2{lt}{nu}{lt}{infinity}. The combined age and degree distribution of nodes shows that old nodes typically have a large degree. There is also a significant correlation in the degrees of neighboring nodes, so that nodes of similar degree are more likely to be connected. The size distributions of the in and out components of the network with respect to a given node{emdash}namely, its {open_quotes}descendants{close_quotes} and {open_quotes}ancestors{close_quotes}{emdash}are also determined. The in component exhibits a robust s{sup {minus}2} power-law tail, where s is the component size. The out component has a typical size of order lnt, and it provides basic insights into the genealogy of the network.

  11. Growing random networks with fitness

    OpenAIRE

    Ergun, G.; Rodgers, GJ

    2001-01-01

    Three models of growing random networks with fitness dependent growth rates are analysed using the rate equations for the distribution of their connectivities. In the first model (A), a network is built by connecting incoming nodes to nodes of connectivity $k$ and random additive fitness $\\eta$, with rate $(k-1)+ \\eta $. For $\\eta >0$ we find the connectivity distribution is power law with exponent $\\gamma=+2$. In the second model (B), the network is built by connecting nodes to nodes of conn...

  12. Neural-like growing networks

    Science.gov (United States)

    Yashchenko, Vitaliy A.

    2000-03-01

    On the basis of the analysis of scientific ideas reflecting the law in the structure and functioning the biological structures of a brain, and analysis and synthesis of knowledge, developed by various directions in Computer Science, also there were developed the bases of the theory of a new class neural-like growing networks, not having the analogue in world practice. In a base of neural-like growing networks the synthesis of knowledge developed by classical theories - semantic and neural of networks is. The first of them enable to form sense, as objects and connections between them in accordance with construction of the network. With thus each sense gets a separate a component of a network as top, connected to other tops. In common it quite corresponds to structure reflected in a brain, where each obvious concept is presented by certain structure and has designating symbol. Secondly, this network gets increased semantic clearness at the expense owing to formation not only connections between neural by elements, but also themselves of elements as such, i.e. here has a place not simply construction of a network by accommodation sense structures in environment neural of elements, and purely creation of most this environment, as of an equivalent of environment of memory. Thus neural-like growing networks are represented by the convenient apparatus for modeling of mechanisms of teleological thinking, as a fulfillment of certain psychophysiological of functions.

  13. Hydrogen production by Hup{sup -} mutant and wild type strains of Rhodobacter capsulatus on dark fermenter effluent of sugar beet thick juice in batch and continuous photobioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Oezguer, Ebru [Middle East Technical Univ., Ankara (Turkey). Dept. of Chemical Engineering; Uyar, Basar [Kocaeli Univ. (Turkey). Dept. of Chemical Engineering; Guergan, Muazzez; Yuecel, Meral [Middle East Technical Univ., Ankara (Turkey). Dept. of Biology

    2010-07-01

    The HYVOLUTION project (EU 6th frame) is aimed to develop an integrated process in which biomass is fermented to acetate, lactate, CO{sub 2} and hydrogen followed by photofermentation of acetate and lactate to hydrogen and CO{sub 2} with photosynthetic purple nonsulfur bacteria (PNS bacteria). Growth and hydrogen production of Rhodobacter capsulatus was investigated on the dark fermenter effluent of thick juice (processed raw sugar beet juice) which contained acetate and NH{sub 4}Cl. In this effluent media, the hydrogen production of wild type bacterium and an uptake-hydrogenase deficient mutant (hup-) were compared in small scale (55 ml) batch and large scale (4 L) continuous photobioreactors in indoor conditions under constant illumination of 2000 lux. In continuous operation mode, the overall hydrogen production yields were 1.84 and 1.92 mol H{sub 2}/mol acetate, the maximum hydrogen productivities were 1.29 and 0.89 mmol H{sub 2}/L.h, for the wild type and mutant strains, respectively. On the other hand, in batch operation mode, the overall hydrogen production yields were 1.25 and 1.44 mol H{sub 2}/mol acetate, the maximum hydrogen productivities were 0.28 and 0.52 mmol H{sub 2}/L.h, for the wild type and mutant strains, respectively. The results show that Rhodobacter capsulatus is capable of using sugar beet thick juice effluent as substrate for hydrogen production; which makes it a suitable bacterium to be employed in integrated termophilic fermentation-photofermentation process. (orig.)

  14. Hydrogen production by hup(-) mutant and wild-type strains of Rhodobacter capsulatus from dark fermentation effluent of sugar beet thick juice in batch and continuous photobioreactors.

    Science.gov (United States)

    Uyar, Basar; Gürgan, Muazzez; Özgür, Ebru; Gündüz, Ufuk; Yücel, Meral; Eroglu, Inci

    2015-10-01

    Photofermentative production of hydrogen is a promising and sustainable process; however, it should be coupled to dark fermentation to become cost effective. In order to integrate dark fermentation and photofermentation, the suitability of dark fermenter effluents for the photofermentative hydrogen production must be demonstrated. In this study, thermophilic dark fermenter effluent (DFE) of sugar beet thick juice was used as a substrate in photofermentation process to compare wild-type and uptake hydrogenase-deficient (hup (-)) mutant strains of Rhodobacter capsulatus by means of hydrogen production and biomass growth. The tests were conducted in small-scale (50 mL) batch and large-scale (4 L) continuous photobioreactors in indoor conditions under continuous illumination. In small scale batch conditions, maximum cell concentrations were 0.92 gdcw/L c and 1.50 gdcw/L c, hydrogen yields were 34 % and 31 %, hydrogen productivities were 0.49 mmol/(L c·h) and 0.26 mmol/(Lc·h), for hup (-) and wild-type cells, respectively. In large-scale continuous conditions, maximum cell concentrations were 1.44 gdcw/L c and 1.87 gdcw/L c, hydrogen yields were 48 and 46 %, and hydrogen productivities were 1.01 mmol/(L c·h) and 1.05 mmol/(L c·h), for hup (-) and wild-type cells, respectively. Our results showed that Rhodobacter capsulatus hup (-) cells reached to a lower maximum cell concentration but their hydrogen yield and productivity were in the same range or superior compared to the wild-type cells in both batch and continuous operating modes. The maximum biomass concentration, yield and productivity of hydrogen were higher in continuous mode compared to the batch mode with both bacterial strains.

  15. Growing the Blockchain information infrastructure

    DEFF Research Database (Denmark)

    Jabbar, Karim; Bjørn, Pernille

    2017-01-01

    In this paper, we present ethnographic data that unpacks the everyday work of some of the many infrastructuring agents who contribute to creating, sustaining and growing the Blockchain information infrastructure. We argue that this infrastructuring work takes the form of entrepreneurial actions......, which are self-initiated and primarily directed at sustaining or increasing the initiator’s stake in the emerging information infrastructure. These entrepreneurial actions wrestle against the affordances of the installed base of the Blockchain infrastructure, and take the shape of engaging...... or circumventing activities. These activities purposefully aim at either influencing or working around the enablers and constraints afforded by the Blockchain information infrastructure, as its installed base is gaining inertia. This study contributes to our understanding of the purpose of infrastructuring, seen...

  16. Growing Vertical in the Flatland.

    Science.gov (United States)

    Robinson, Joshua A

    2016-01-26

    The world of two-dimensional (2D) heterostructures continues to expand at a rate much greater than anyone could have predicted 10 years ago, but if we are to make the leap from science to technology, many materials challenges must still be overcome. Recent advances, such as those by Liu et al. in this issue of ACS Nano, demonstrate that it is possible to grow rotationally commensurate 2D heterostructures, which could pave the way toward single crystal van der Waals solids. In this Perspective, I provide some insight into a few of the challenges associated with growth of heterostructures, and discuss some of the recent works that help us better understand synthetic realization of 2D heterostructures.

  17. Viking Disruptions or Growing Integration?

    DEFF Research Database (Denmark)

    Sindbæk, Søren Michael

    2012-01-01

    Long-distance communication has emerged as a particular focus for archaeological exploration using network theory, analysis, and modelling. Initial attempts to adapt methods from social network analysis to archaeological data have, however, struggled to produce decisive results. This paper...... demonstrates how formal network analysis can be combined with a contextual reading of evidence relating to a long-distance communication network in the past. A study of the combined distributions of ten vessel types in 152 settlement sites from the 10th century suggests the outline of the core structure...... of the network. The model implies that 10th century long-distance exchange in the North Sea region featured long-distance links equal to those of the Carolingian emporia trade, and represented a growth in terms of new axes of integration, above all the growing links between the Scandinavian Peninsula...

  18. Growing bubbles rising in line

    Directory of Open Access Journals (Sweden)

    John F. Harper

    2001-01-01

    Full Text Available Over many years the author and others have given theories for bubbles rising in line in a liquid. Theory has usually suggested that the bubbles will tend towards a stable distance apart, but experiments have often showed them pairing off and sometimes coalescing. However, existing theory seems not to deal adequately with the case of bubbles growing as they rise, which they do if the liquid is boiling, or is a supersaturated solution of a gas, or simply because the pressure decreases with height. That omission is now addressed, for spherical bubbles rising at high Reynolds numbers. As the flow is then nearly irrotational, Lagrange's equations can be used with Rayleigh's dissipation function. The theory also works for bubbles shrinking as they rise because they dissolve.

  19. Morphogenesis of Growing Soft Tissues

    Science.gov (United States)

    Dervaux, Julien; Ben Amar, Martine

    2008-08-01

    Recently, much attention has been given to a noteworthy property of some soft tissues: their ability to grow. Many attempts have been made to model this behavior in biology, chemistry, and physics. Using the theory of finite elasticity, Rodriguez has postulated a multiplicative decomposition of the geometric deformation gradient into a growth-induced part and an elastic one needed to ensure compatibility of the body. In order to fully explore the consequences of this hypothesis, the equations describing thin elastic objects under finite growth are derived. Under appropriate scaling assumptions for the growth rates, the proposed model is of the Föppl von Kármán type. As an illustration, the circumferential growth of a free hyperelastic disk is studied.

  20. Infection Dynamics on Growing Networks

    Science.gov (United States)

    Lai, Ying-Cheng; Liu, Zonghua; Ye, Nong

    We consider the entire spectrum of architectures for large, growing, and complex networks, ranging from being heterogeneous (scale-free) to homogeneous (random or small-world), and investigate the infection dynamics by using a realistic three-state epidemiological model. In this framework, a node can be in one of the three states: susceptible (S), infected (I), or refractory (R), and the populations in the three groups are approximately described by a set of nonlinear differential equations. Our heuristic analysis predicts that, (1) regardless of the network architecture, there exists a substantial fraction of nodes that can never be infected, and (2) heterogeneous networks are relatively more robust against spread of infection as compared with homogeneous networks. These are confirmed numerically. We have also considered the problem of deliberate immunization for preventing wide spread of infection, with the result that targeted immunization can be quite effective for heterogeneous networks. We believe these results are important for a host of problems in many areas of natural science and engineering, and in social sciences as well.

  1. Growing plants on atoll soils

    Energy Technology Data Exchange (ETDEWEB)

    Stone, E L; Migvar, L; Robison, W L

    2000-02-16

    Many years ago people living on atolls depended entirely on foods gathered from the sea and reefs and grown on land. Only a few plants, such as coconut (ni), Pandanus (bob), and arrowroot (mok-mok), could be grown on the lower rainfall atolls, although adequate groundwater conditions also allowed taro (iaraj, kotak, wot) to be cultivated. On higher rainfall atolls, breadfruit (ma) was a major food source, and banana (binana, kepran), lime (laim), and taros (iaraj, kotak, wot) could be grown. The early atoll populations were experts in growing plants that were vital to sustaining their nutrition requirements and to providing materials for thatch, basketry, cordage, canoe construction, flowers, and medicine. They knew which varieties of food plants grew well or poorly on their atolls, how to propagate them, and where on their atoll they grew best. They knew the uses of most native plants and what the various woods were well suited for. Many varieties of Pandanus (bob) and breadfruit (ma) grew well with high rainfall, but only a few produced well on drier atolls. Such information had been passed down through the generations although some of it has been lost in the last century. Today there are new plants and new varieties of existing plants that can be grown on atolls. There are also new materials and information on how to grow both the old and new plants more effectively. However, there are also introduced weeds and pests to control. Today, there is also an acute need to grow more of the useful plants adapted to atolls. Increasing numbers of people living on an atoll without an equal increase in income or food production stretches the available food supplies. Much has been written about the poor conditions for plant growth on atolls. As compared with many places in the world where crops are grown, however, atolls can provide some highly favorable conditions. For instance, the driving force for plant growth is sunlight, and on atolls light is abundant throughout the

  2. Case grows for climate change

    Energy Technology Data Exchange (ETDEWEB)

    Hileman, B.

    1999-08-09

    In the four years since the IPCC stated that 'the balance of evidence suggests a discernible human influence on global climate', evidence for anomalous warming has become more compelling, and as a result scientists have become more concerned that human-induced climate change has already arrived. The article summarises recent extra evidence on global temperatures, carbon dioxide measurements, ice shelf breakup, coral bleaching, unstable climates and improved climate models. At the time of the Kyoto conference, the US became keen on the idea that enhancing forest and soil carbon sequestration was a good way to offset emissions reduction targets. Congress is however under the opinion on that the Kyoto protocol presents a threat to the US economy, and senate is very unlikely to ratify the protocol during the Clinton Administration. The debate as to whether the US government should mandate major emission reduction or wait for more scientific certainty may continue for a number of years, but, growing concern of scientists and the public for the harmful effects of climate change may cause a change. 4 figs., 8 photos.

  3. Growing and evolving soft robots.

    Science.gov (United States)

    Rieffel, John; Knox, Davis; Smith, Schuyler; Trimmer, Barry

    2014-01-01

    Completely soft and flexible robots offer to revolutionize fields ranging from search and rescue to endoscopic surgery. One of the outstanding challenges in this burgeoning field is the chicken-and-egg problem of body-brain design: Development of locomotion requires the preexistence of a locomotion-capable body, and development of a location-capable body requires the preexistence of a locomotive gait. This problem is compounded by the high degree of coupling between the material properties of a soft body (such as stiffness or damping coefficients) and the effectiveness of a gait. This article synthesizes four years of research into soft robotics, in particular describing three approaches to the co-discovery of soft robot morphology and control. In the first, muscle placement and firing patterns are coevolved for a fixed body shape with fixed material properties. In the second, the material properties of a simulated soft body coevolve alongside locomotive gaits, with body shape and muscle placement fixed. In the third, a developmental encoding is used to scalably grow elaborate soft body shapes from a small seed structure. Considerations of the simulation time and the challenges of physically implementing soft robots in the real world are discussed.

  4. Pediatric Ovarian Growing Teratoma Syndrome

    Directory of Open Access Journals (Sweden)

    Rebecca M. Rentea

    2017-01-01

    Full Text Available Ovarian immature teratoma is a germ cell tumor that comprises less than 1% of ovarian cancers and is treated with surgical debulking and chemotherapy depending on stage. Growing teratoma syndrome (GTS is the phenomenon of the growth of mature teratoma elements with normal tumor markers during or following chemotherapy for treatment of a malignant germ cell tumor. These tumors are associated with significant morbidity and mortality due to invasive and compressive growth as well as potential for malignant transformation. Current treatment modality is surgical resection. We discuss a 12-year-old female who presented following resection of a pure ovarian immature teratoma (grade 3, FIGO stage IIIC. Following chemotherapy and resection of a pelvic/liver recurrence demonstrating mature teratoma, she underwent molecular genetics based chemotherapeutic treatment. No standardized management protocol has been established for the treatment of GTS. The effect of chemotherapeutic agents for decreasing the volume of and prevention of expansion is unknown. We review in detail the history, diagnostic algorithm, and previous reported pediatric cases as well as treatment options for pediatric patients with GTS.

  5. [Growing old differently: Transdisciplinary perspective].

    Science.gov (United States)

    Zimmermann, H-P

    2015-04-01

    Growing old differently: the phrase is intended to call something other to mind than merely the fact that images and forms of old age and aging have multiplied and diversified to an enormous extent. The suggestion put forward here is that otherness (as opposed to mere differences) should be positively reinforced. In other words, it is not just a matter of noting different forms of old age and aging but more than this, of seeking out opportunities for aging differently. In order to explore this, the article follows an older strand of theory, which has recently come to be frequently quoted in gerontology: the phenomenology of difference as reasoned analytically by Lévinas and Sartre and applied to gerontology by Améry and de Beauvoir. Here, opportunities for aging crucially depend on the way we look at it, how we observe and describe it and not least, how gerontology frames it. A distinction is made between two perspectives and their associated consequences for old age: alienation and alterity. Alienation means looking at old age above all as a disconcerting "other", as a perplexing, problematic deviation from the norm of vitality. Alterity, by contrast, refers to different options for living life in old age: options to be explored and opened up in contradistinction to cultural or academic alienation. Not least, the article appeals for diversity in scholarly approaches and for cross-disciplinary perspectives.

  6. Menopausal women's positive experience of growing older

    DEFF Research Database (Denmark)

    Hvas, Lotte

    2006-01-01

    This paper aims to describe menopausal women's positive experience of growing older and becoming middle-aged.......This paper aims to describe menopausal women's positive experience of growing older and becoming middle-aged....

  7. Bariatric amputee: A growing problem?

    Science.gov (United States)

    Kulkarni, Jai; Hannett, Dominic P; Purcell, Steven

    2015-06-01

    This study reviewed prevalence of patients with lower limb amputations with above normal weight profile, with body mass index over 25, in seven disablement services centres managing their amputee rehabilitation in the United Kingdom. To review two clinical standards of practice in amputee rehabilitation. Ambulant lower limb amputees should have their body weight recorded on an electronic information system, with identification of cohort with body weight >100 kg. Lower limb amputees to be provided with suitable weight-rated prosthesis. Observational study of clinical practice. Data were collected from the Clinical Information Management Systems. Inclusion criteria--subjects were ambulant prosthetic users with some prosthetic intervention in the last 5 years and had at least one lower limb amputation. In 96% of patients, the weight record profile was maintained. In addition, 86% were under 100 kg, which is the most common weight limit of prosthetic componentry. Of 15,204 amputation levels, there were 1830 transfemoral and transtibial sites in users with body weight over 100 kg. In 60 cases, the prosthetic limb build was rated to be below the user body weight. In 96% of our patients, body weight was documented, and in 97%, the prosthetic limb builds were within stated body weight limits, but this may not be the case in all the other disablement services centres in the United Kingdom. Also, the incidence of obesity in the United Kingdom is a growing problem, and the health issues associated with obesity are further compounded in the amputee population. Prosthetic componentry has distinct weight limits which must be considered during prescription. As people with amputation approach the limits of specific components, clinicians are faced with the challenge of continued provision in a safe and suitable manner. This article reviews the amputee population and the current national profile to consider trends in provision and the incidence of these challenges. © The

  8. In vitro and in vivo safety assessment of edible blue-green algae, Nostoc commune var. sphaeroides Kützing and Spirulina plantensis.

    Science.gov (United States)

    Yang, Yue; Park, Youngki; Cassada, David A; Snow, Daniel D; Rogers, Douglas G; Lee, Jiyoung

    2011-07-01

    Blue-green algae (BGA) have been consumed as food and herbal medicine for centuries. However, safety for their consumption has not been well investigated. This study was undertaken to evaluate in vitro and in vivo toxicity of cultivated Nostoc commune var. sphaeroides Kützing (NO) and Spirulina platensis (SP). Neither NO nor SP contained detectable levels of microcystin (MC)-LA, MC-RR, MC-LW and MC-LR by LC/MS/MS. Cell viability remained ∼70-80% when HepG2 cells were incubated with 0-500 μg/ml of hexane, chloroform, methanol and water-extractable fractions of NO and SP. Four-week-old male and female C57BL/6J mice were fed an AIN-93G/M diet supplemented with 0%, 2.5% or 5% of NO and SP (wt/wt) for 6 months. For both genders, BGA-rich diets did not induce noticeable abnormality in weight gain and plasma alanine aminotransferase (ALT) and aspartate aminotransferase concentrations except a significant increase in plasma ALT levels by 2.5% NO supplementation in male mice at 6 month. Histopathological analysis of livers, however, indicated that BGA did not cause significant liver damage compared with controls. In conclusion, our results suggest that NO and SP are free of MC and the long-term dietary supplementation of up to 5% of the BGA may be consumed without evident toxic side-effects. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Removal of the effect of ammonium on the regulation of nitrogenase enzyme in Rhodobacter capsulatus DSM1710 for improved hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Pekgoez, Guelsah; Guenduez, Ufuk [Middle East Technical Univ. (Turkey). Dept. of Biology; Eroglu, Inci [Middle East Technical Univ. (Turkey). Dept. of Chemical Engineering; Rakhely, Gabor [Szeged Univ. (Hungary). Dept. of Biotechnology

    2010-07-01

    Photofermentative biohydrogen production by purple non-sulfur (PNS) bacteria is a renewable and clean way of producing hydrogen. Hydrogen production by PNS bacteria, Rhodobacter capsulatus, is mediated mainly by nitrogenases, which primarily fix molecular nitrogen to ammonium and produce hydrogen as byproduct. The reaction catalyzed by nitrogenases requires a lot of energy. Hence, there is a complex regulation on nitrogenase enzyme complex, consequently, on hydrogen production. Whenever ammonium, which is the end product of nitrogen fixation reaction, is found in the environment, hydrogen production stops. GlnB and GlnK proteins are the critical regulatory proteins in ammonium dependent regulation of the nitrogenase gene expression. In this study, the aim is to release the ammonium regulation on nitrogenase enzyme by inactivating glnB and glnK genes. For this purpose, relevant recombinant vectors were constructed; R.capsulatus glnB- strain was obtained. The double R.capsulatus glnB{sup -}glnK{sup -} strain, able to produce hydrogen independent of ammonium concentration of the environment is to be obtained. (orig.)

  10. Dietary Karaya Saponin and Rhodobacter capsulatus Exert Hypocholesterolemic Effects by Suppression of Hepatic Cholesterol Synthesis and Promotion of Bile Acid Synthesis in Laying Hens

    Directory of Open Access Journals (Sweden)

    Sadia Afrose

    2010-01-01

    Full Text Available This study was conducted to elucidate the mechanism underlying the hypolipidemic action of karaya saponin or Rhodobacter (R. capsulatus. A total of 40 laying hens (20-week-old were assigned into four dietary treatment groups and fed a basal diet (as a control or basal diets supplemented with either karaya saponin, R. capsulatus, or both for 60 days. The level of serum low-density-lipoprotein cholesterol and the levels of cholesterol and triglycerides in the serum, liver, and egg yolk were reduced by all the supplementations (<.05. Liver bile acid concentration and fecal concentrations of cholesterol, triacylglycerol, and bile acid were simultaneously increased by the supplementation of karaya saponin, R. capsulatus, and the combination of karaya saponin and R. capsulatus (<.05. The supplementation of karaya saponin, R. capsulatus, and the combination of karaya saponin and R. capsulatus suppressed the incorporation of 14C from 1-14C-palmitic acid into the fractions of total lipids, phospholipids, triacylglycerol, and cholesterol in the liver in vitro (<.05. These findings suggest that the hypocholesterolemic effects of karaya saponin and R. capsulatus are caused by the suppression of the cholesterol synthesis and the promotion of cholesterol catabolism in the liver.

  11. Potential of Rhodobacter capsulatus Grown in Anaerobic-Light or Aerobic-Dark Conditions as Bioremediation Agent for Biological Wastewater Treatments

    Directory of Open Access Journals (Sweden)

    Stefania Costa

    2017-02-01

    Full Text Available The use of microorganisms to clean up wastewater provides a cheaper alternative to the conventional treatment plant. The efficiency of this method can be improved by the choice of microorganism with the potential of removing contaminants. One such group is photosynthetic bacteria. Rhodobacter capsulatus is a purple non-sulfur bacterium (PNSB found to be capable of different metabolic activities depending on the environmental conditions. Cell growth in different media and conditions was tested, obtaining a concentration of about 108 CFU/mL under aerobic-dark and 109 CFU/mL under anaerobic-light conditions. The biomass was then used as a bioremediation agent for denitrification and nitrification of municipal wastewater to evaluate the potential to be employed as an additive in biological wastewater treatment. Inoculating a sample of mixed liquor withdrawn from the municipal wastewater treatment plant with R. capsulatus grown in aerobic-dark and anaerobic-light conditions caused a significant decrease of N-NO3 (>95%, N-NH3 (70% and SCOD (soluble chemical oxygen demand (>69%, independent of the growth conditions. A preliminary evaluation of costs indicated that R. capsulatus grown in aerobic-dark conditions could be more convenient for industrial application.

  12. Synergistic dark and photo-fermentation continuous system for hydrogen production from molasses by Clostridium acetobutylicum ATCC 824 and Rhodobacter capsulatus DSM 1710.

    Science.gov (United States)

    Morsy, Fatthy Mohamed

    2017-04-01

    This study investigated synergistic dark and photo-fermentation using continuous fermentation system (CFS). The system relies on connecting several fermenters from bottom of one to top culture level of the next in a manner that allows for delaying movement of the substrate and thus for its full consumption. While H 2 was collected, CFS allowed for moving liquid byproducts toward the outlet and hence continuous productivity. CFS could be efficiently used for: (1) Continuous dark and photo-fermentation H 2 production by Clostridium acetobutylicum and Rhodobacter capsulatus producing 5.65moleH 2 mole -1 hexose; (2) Continuous dark-fermentation synergistic H 2 , acetone, butanol and ethanol (ABE) production by C. acetobutylicum which produced per mole hexose, 2.43mol H 2 along with 73.08g ABE (3) Continuous H 2 and methane production by C. acetobutylicum and bacterial sludge producing, per mole hexose, 1.64mol pure H 2 and 2.56mol CH 4 mixed with 0.37mol H 2 ·The hydraulic retention time (HRT) for whole system was short where organic acids produced in dark-fermentation in first fermenter were synergistically utilized for H 2 production by R. capsulatus in subsequent fermenters. CFS is suitable for fast-digestible sugars but not lignocelluloses or other hard-digestible organics, requiring prolonged HRT, unless such polymeric organics were hydrolyzed prior to fermentation. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Cloning of the sdsA gene encoding solanesyl diphosphate synthase from Rhodobacter capsulatus and its functional expression in Escherichia coli and Saccharomyces cerevisiae.

    Science.gov (United States)

    Okada, K; Kamiya, Y; Zhu, X; Suzuki, K; Tanaka, K; Nakagawa, T; Matsuda, H; Kawamukai, M

    1997-10-01

    Different organisms produce different species of isoprenoid quinones, each with its own distinctive length. These differences in length are commonly exploited in microbial classification. The side chain length of quinone is determined by the nature of the polyprenyl diphosphate synthase that catalyzes the reaction. To determine if the side chain length of ubiquinone (UQ) has any distinct role to play in the metabolism of the cells in which it is found, we cloned the solanesyl diphosphate synthase gene (sdsA) from Rhodobacter capsulatus SB1003 and expressed it in Escherichia coli and Saccharomyces cerevisiae. Sequence analysis revealed that the sdsA gene encodes a 325-amino-acid protein which has similarity (27 to 40%) with other prenyl diphosphate synthases. Expression of the sdsA gene complemented a defect in the octaprenyl diphosphate synthase gene of E. coli and the nonrespiratory phenotype resulting from a defect in the hexaprenyl diphosphate synthase gene of S. cerevisiae. Both E. coli and S. cerevisiae expressing the sdsA gene mainly produced solanesyl diphosphate, which resulted in the synthesis of UQ-9 without any noticeable effect on the growth of the cells. Thus, it appears that UQ-9 can replace the function of UQ-8 in E. coli and UQ-6 in S. cerevisiae. Taken together with previous results, the results described here imply that the side chain length of UQ is not a critical factor for the survival of microorganisms.

  14. Effect of light-dark cycles on hydrogen and poly-β-hydroxybutyrate production by a photoheterotrophic culture and Rhodobacter capsulatus using a dark fermentation effluent as substrate.

    Science.gov (United States)

    Montiel Corona, Virginia; Le Borgne, Sylvie; Revah, Sergio; Morales, Marcia

    2017-02-01

    A Rhodobacter capsulatus strain and a photoheterotrophic culture (IZT) were cultivated to produce hydrogen under different light-dark cycles. A dark fermentation effluent (DFE) was used as substrate. It was found that IZT culture had an average cumulative hydrogen production (Paccum H2) of 1300±43mLH2L-1 under continuous illumination and light-dark cycles of 30 or 60min. In contrast, R. capsulatus reduced its Paccum H2 by 20% under 30:30min light-dark cycles, but tripled its poly-β-hydroxybutyrate (PHB) content (308±2mgPHB gdw-1) compared to continuous illumination. The highest PHB content by IZT culture was 178±10mgPHB gdw-1 under 15:15min light-dark cycles. PCR-DGGE analysis revealed that the IZT culture was mainly composed of Rhodopseudomonas palustris identified with high nucleotide similarity (99%). The evaluated cultures might be used for hydrogen and PHB production. They might provide energy savings by using light-dark cycles and DFE valorization. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Recombinant Rhodobacter capsulatus xanthine dehydrogenase, a useful model system for the characterization of protein variants leading to xanthinuria I in humans.

    Science.gov (United States)

    Leimkuhler, Silke; Hodson, Rachael; George, Graham N; Rajagopalan, K V

    2003-06-06

    Rhodobacter capsulatus xanthine dehydrogenase (XDH) forms an (alphabeta)2 heterotetramer and is highly homologous to homodimeric eukaryotic XDHs. The crystal structures of bovine XDH and R. capsulatus XDH showed that the two proteins have highly similar folds. We have developed an efficient system for the recombinant expression of R. capsulatus XDH in Escherichia coli. The recombinant protein shows spectral features and a range of substrate specificities similar to bovine milk xanthine oxidase. However, R. capsulatus XDH is at least 5 times more active than bovine XDH and, unlike mammalian XDH, does not undergo the conversion to the oxidase form. EPR spectra were obtained for the FeS centers of the enzyme showing an axial signal for FeSI, which is different from that reported for xanthine oxidase. X-ray absorption spectroscopy at the iron and molybdenum K-edge and the tungsten LIII-edge have been used to probe the different metal coordinations of variant forms of the enzyme. Based on a mutation identified in a patient suffering from xanthinuria I, the corresponding arginine 135 was substituted to a cysteine in R. capsulatus XDH, and the protein variant was purified and characterized. Two different forms of XDH-R135C were purified, an active (alphabeta)2 heterotetrameric form and an inactive (alphabeta) heterodimeric form. The active form contains a full complement of redox centers, whereas in the inactive form the FeSI center is likely to be missing.

  16. Identification of a Rhodobacter capsulatus L-cysteine desulfurase that sulfurates the molybdenum cofactor when bound to XdhC and before its insertion into xanthine dehydrogenase.

    Science.gov (United States)

    Neumann, Meina; Stöcklein, Walter; Walburger, Anne; Magalon, Axel; Leimkühler, Silke

    2007-08-21

    The molybdenum cofactor (Moco) containing enzymes aldehyde oxidase and xanthine dehydrogenase (XDH) require for activity a sulfuration step that inserts a terminal sulfur ligand into Moco. XdhC was shown to be essential for the production of active XDH in Rhodobacter capsulatus but is itself not a subunit of the purified enzyme. XdhC binds stoichiometric amounts of Moco and is further able to transfer its bound Moco to XDH. Previous work suggested that XdhC particularly stabilizes the sulfurated form of Moco before the insertion into XDH. In this work, we identify an R. capsulatus l-cysteine desulfurase, NifS4, which is involved in the formation of the Mo=S ligand of Moco. We show that NifS4 interacts with XdhC and not with XDH. NifS4 mobilizes sulfur from l-cysteine by formation of a protein-bound persulfide intermediate and transfers this sulfur further to Moco. This reaction was shown to be more effective than the chemical sulfuration of Moco using sulfide as sulfur source. Further studies clearly showed that Moco is sulfurated before the insertion into XDH, while it is bound to XdhC. Conclusively, XdhC has a versatile role in R. capsulatus: binding of Moco, interaction with NifS4 for the sulfuration of Moco, protection of sulfurated Moco from oxidation, and further transfer to XDH.

  17. Magnetically controlled growing rods for scoliosis surgery.

    Science.gov (United States)

    Metkar, Umesh; Kurra, Swamy; Quinzi, David; Albanese, Stephen; Lavelle, William F

    2017-02-01

    Early onset scoliosis can be both a disfiguring as well as a life threatening condition. When more conservative treatments fail, pediatric spinal surgeons are forced to consider operative interventions. Traditionally, these interventions have involved the insertion of a variety of implants into the patient with a limited number of anchor points controlling the spine. In the past, these pediatric patients have had multiple surgeries for elective lengthening of these devices to facilitate their growth while attempting to control the scoliosis. These patients often experience a physical and emotional toll from their multiple repeated surgeries. Growing spine techniques have also had a noted high complication rate due to implant dislodgement and infections. Recently, the development of non-invasively, self-lengthening growing rods has occurred. These devices have the potential to allow for the devices to be lengthened magnetically in a conscious patient in the surgeon's office. Areas covered: This review summarized previously published articles in the English literature using a key word search in PubMed for: 'magnetically controlled growing rods', 'Magec rods', 'magnetic growing rods' and 'growing rods'. Expert commentary: Magnetically controlled growing rods have an advantage over growing rods in lengthening the growing spine in the absence of repetitive surgeries.

  18. (GrOW) Frequently Asked Questions

    International Development Research Centre (IDRC) Digital Library (Canada)

    Alejandra

    How many applications will be shortlisted at the end of the first stage? GrOW envisages that up to 4 selected teams will be asked to submit a full research proposal for review and funding consideration. How is the review process conducted? Upon receiving complete applications, a review process begins by the GrOW team, ...

  19. A two-stage, two-organism process for biohydrogen from glucose

    OpenAIRE

    Redwood, MD; Macaskie, LE

    2006-01-01

    H2 can potentially be produced in a two-stage biological process: the fermentation of glucose by Escherichia coli HD701 and the photofermentation of the residual medium by Rhodobacter sphaeroides O.U. 001. In a typical batch fermentation, E. coli consumed glucose and produced H2, organic end-products and biomass. Organic end-products and residual glucose were removed during subsequent photofermentation by R. sphaeroides, with associated growth and neutralization of pH. However, photoproductio...

  20. Manipulating the Energetics and Rates of Electron Transfer in Rhodobacter capsulatus Reaction Centers with Asymmetric Pigment Content

    Energy Technology Data Exchange (ETDEWEB)

    Faries, Kaitlyn M. [Department; Dylla, Nicholas P. [Biosciences Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Hanson, Deborah K. [Biosciences Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Holten, Dewey [Department; Laible, Philip D. [Biosciences Division, Argonne National Laboratory, Lemont, Illinois 60439, United States; Kirmaier, Christine [Department

    2017-07-17

    Seemingly redundant parallel pathways for electron transfer (ET), composed of identical sets of cofactors, are a cornerstone feature of photosynthetic reaction centers (RCs) involved in light-energy conversion. In native bacterial RCs, both A and B branches house one bacteriochlorophyll (BChl) and one bacteriopheophytin (BPh), but the A branch is used exclusively. Described herein are the results-obtained for two Rhodobacter capsulatus RCs with an unnaturally high degree of cofactor asymmetry, two BPh on the RC's B side and two BChl on the A side. These pigment changes derive, respectively, from the His(M180)Leu mutation [a BPh ((Phi(B)) replaces the B-side BChl (BB)], and the Leu(M212)His mutation [a BChl (beta(A))) replaces the A-side BPh (H-A)]. Additionally, Tyr(M208)Phe was employed to disfavor ET to the A branch; in one mutant, Val(M131)Glu creates a hydrogen bond to H-B to enhance ET to H-B. In both Phi(B) mutants, the decay kinetics of the excited primary ET donor (P*) resolve three populations with lifetimes of similar to 9 ps (50-60%), similar to 40 ps (10-20%), and similar to 200 ps (20-30%), with P+Phi(-)(B) formed predominantly from the 9 ps fraction. The 50-60% yield of P+Phi(B)- is the highest yet observed for a Phi(B)-containing RC. The results provide insight into factors needed for efficient multistep ET.

  1. Microsatellite Primers for Fungus-Growing Ants

    DEFF Research Database (Denmark)

    Villesen Fredsted, Palle; Gertsch, Pia J.; Boomsma, Jacobus Jan (Koos)

    2002-01-01

    We isolated five polymorphic microsatellite loci from a library of two thousand recombinant clones of two fungus-growing ant species, Cyphomyrmex longiscapus and Trachymyrmex cf. zeteki. Amplification and heterozygosity were tested in five species of higher attine ants using both the newly...... developed primers and earlier published primers that were developed for fungus-growing ants. A total of 20 variable microsatellite loci, developed for six different species of fungus-growing ants, are now available for studying the population genetics and colony kin-structure of these ants....

  2. Microsatellite primers for fungus-growing ants

    DEFF Research Database (Denmark)

    Villesen, Palle; Gertsch, P J; Boomsma, JJ

    2002-01-01

    We isolated five polymorphic microsatellite loci from a library of two thousand recombinant clones of two fungus-growing ant species, Cyphomyrmex longiscapus and Trachymyrmex cf. zeteki. Amplification and heterozygosity were tested in five species of higher attine ants using both the newly...... developed primers and earlier published primers that were developed for fungus-growing ants. A total of 20 variable microsatellite loci, developed for six different species of fungus-growing ants, are now available for studying the population genetics and colony kin-structure of these ants....

  3. Growing America's Energy Future

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-06-01

    The emerging U.S. bioenergy industry provides a secure and growing supply of transportation fuels, biopower, and bioproducts produced from a range of abundant, renewable biomass resources. Bioenergy can help ensure a secure, sustainable, and economically sound future by reducing U.S. dependence on foreign oil, developing domestic clean energy sources, and generating domestic green jobs. Bioenergy can also help address growing concerns about climate change by reducing greenhouse gas emissions to create a healthier environment for current and future generations.

  4. Functional assignment of gene AAC16202.1 from Rhodobacter capsulatus SB1003: new insights into the bacterial SDR sorbitol dehydrogenases family.

    Science.gov (United States)

    Sola-Carvajal, Agustín; García-García, María Inmaculada; Sánchez-Carrón, Guiomar; García-Carmona, Francisco; Sánchez-Ferrer, Alvaro

    2012-11-01

    Short-chain dehydrogenases/reductases (SDR) constitute one of the largest enzyme superfamilies with over 60,000 non-redundant sequences in the database, many of which need a correct functional assignment. Among them, the gene AAC16202.1 (NCBI) from Rhodobacter capsulatus SB1003 has been assigned in Uniprot both as a sorbitol dehydrogenase (#D5AUY1) and, as an N-acetyl-d-mannosamine dehydrogenase (#O66112), both enzymes being of biotechnological interest. When the gene was overexpressed in Escherichia coli Rosetta (DE3)pLys, the purified enzyme was not active toward N-acetyl-d-mannosamine, whereas it was active toward d-sorbitol and d-fructose. However, the relative activities toward xylitol and l-iditol (0.45 and 6.9%, respectively) were low compared with that toward d-sorbitol. Thus, the enzyme could be considered sorbitol dehydrogenase (SDH) with very low activity toward xylitol, which could increase its biotechnological interest for determining sorbitol without the unspecific cross-determination of added xylitol in food and pharma compositions. The tetrameric enzyme (120 kDa) showed similar catalytic efficiency (2.2 × 10(3) M(-1) s(-1)) to other sorbitol dehydrogenases for d-sorbitol, with an optimum pH of 9.0 and an optimum temperature of 37 °C. The enzyme was also more thermostable than other reported SDH, ammonium sulfate being the best stabilizer in this respect, increasing the melting temperature (T(m)) up to 52.9 °C. The enzyme can also be considered as a new member of the Zn(2+) independent SDH family since no effect on activity was detected in the presence of divalent cations or chelating agents. Finally, its in silico analysis enabled the specific conserved sequence blocks that are the fingerprints of bacterial sorbitol dehydrogenases and mainly located at C-terminal of the protein, to be determined for the first time. This knowledge will facilitate future data curation of present databases and a better functional assignment of newly described

  5. Homologues of Genetic Transformation DNA Import Genes Are Required for Rhodobacter capsulatus Gene Transfer Agent Recipient Capability Regulated by the Response Regulator CtrA.

    Science.gov (United States)

    Brimacombe, Cedric A; Ding, Hao; Johnson, Jeanette A; Beatty, J Thomas

    2015-08-01

    Gene transfer agents (GTAs) morphologically resemble small, double-stranded DNA (dsDNA) bacteriophages; however, their only known role is to package and transfer random pieces of the producing cell genome to recipient cells. The best understood GTA is that of Rhodobacter capsulatus, termed RcGTA. We discovered that homologues of three genes involved in natural transformation in other bacteria, comEC, comF, and comM, are essential for RcGTA-mediated gene acquisition. This paper gives genetic and biochemical evidence that RcGTA-borne DNA entry into cells requires the ComEC and ComF putative DNA transport proteins and genetic evidence that putative cytoplasmic ComM protein of unknown function is required for recipient capability. Furthermore, the master regulator of RcGTA production in bacterial horizontal gene transfer mechanisms, where donor DNA is packaged in transducing phage-like particles and recipient cells take up DNA using natural transformation-related machinery. Both of these differentiated subsets of a culture population, donors and recipients, are dependent on the same response regulator, CtrA. Horizontal gene transfer (HGT) is a major driver of bacterial evolution and adaptation to environmental stresses. Traits such as antibiotic resistance or metabolic properties can be transferred between bacteria via HGT; thus, HGT can have a tremendous effect on the fitness of a bacterial population. The three classically described HGT mechanisms are conjugation, transformation, and phage-mediated transduction. More recently, the HGT factor GTA was described, where random pieces of producing cell genome are packaged into phage-like particles that deliver DNA to recipient cells. In this report, we show that transport of DNA borne by the R. capsulatus RcGTA into recipient cells requires key genes previously thought to be specific to natural transformation pathways. These findings indicate that RcGTA combines central aspects of phage-mediated transduction and natural

  6. The SGIA and the Common Growing Language

    Directory of Open Access Journals (Sweden)

    Laurentiu CIOVICA

    2011-01-01

    Full Text Available Human or virtual agents are presented in our lives daily. They serve our purposes and represent us in different many situations. Nowadays the number of virtual agents is increasing daily because they are cheaper, faster and more accurate than human agents. Our aim in this article is to define a new type of intelligent agent called SGIA – Self Growing Intelligent Agent and a new defining language for it. The SGIA agent is an intelligent agent with all the common agents’ characteristics and with other special one: that to learn and grow by itself in knowledge and size.

  7. Growing pioneer plants for a lunar base

    Science.gov (United States)

    Kozyrovska, N. O.; Lutvynenko, T. L.; Korniichuk, O. S.; Kovalchuk, M. V.; Voznyuk, T. M.; Kononuchenko, O.; Zaetz, I.; Rogutskyy, I. S.; Mytrokhyn, O. V.; Mashkovska, S. P.; Foing, B. H.; Kordyum, V. A.

    A precursory scenario of cultivating the first plants in a lunar greenhouse was elaborated in frames of a conceptual study to grow plants for a permanently manned lunar base. A prototype plant growth system represents an ornamental plant Tagetes patula L. for growing in a lunar rock anorthosite as a substrate. Microbial community anticipated to be in use to support a growth and development of the plant in a substrate of low bioavailability and provide an acceptable growth and blossoming of T. patula under growth limiting conditions.

  8. Growing up Female: As Six become One

    Science.gov (United States)

    Balto, Karen; Balto, Sylvia

    1971-01-01

    Growing up Female: As Six Become One" is an excellent film for people of any age and appropriate for any group. The film explores the lives of six American women showing how they are socialized and what their roles in society are. (Author)

  9. Growing Languages with Metamorphic Syntax Macros

    DEFF Research Database (Denmark)

    Brabrand, Claus; Schwartzbach, Michael Ignatieff

    2002-01-01

    simultaneously on multiple parse trees at once. The result is a highly flexible mechanism for growing new language constructs without resorting to compile-time programming. In fact, whole new languages can be defined at surprisingly low cost.This work is fully implemented as part of the bigwig system...

  10. Pueblo Girls: Growing Up in Two Worlds.

    Science.gov (United States)

    Keegan, Marcia

    This book portrays San Ildefonso Pueblo on the east bank of the Rio Grande river in New Mexico through the lives of Sonja, age 10, and her sister Desiree, age 8. Growing up in San Ildefonso Pueblo, the girls enjoy the same activities as other American girls, such as basketball, cheerleading, playing video games, and sending e-mail. But they also…

  11. What a Pain! Kids and Growing Pains

    Science.gov (United States)

    ... Steven Dowshen, MD Date reviewed: June 2015 For Teens For Kids For Parents MORE ON THIS TOPIC Why Do I Have Pain? How Do Pain Relievers Work? Growth Disorders I'm Growing Up - But Am I Normal? What Medicines Are and What They Do Feeling Too Tall or Too Short Contact Us Print Resources Send ...

  12. Growing Income Inequality Threatens American Education

    Science.gov (United States)

    Duncan, Greg J.; Murnane, Richard J.

    2014-01-01

    The first of two articles in consecutive months describes the origins and nature of growing income inequality, and some of its consequences for American children. It documents the increased family income inequality that's occurred over the past 40 years and shows that the increased income disparity has been more than matched by an expanding…

  13. Growing Up in Germany: A National Report.

    Science.gov (United States)

    Krappmann, Lothar

    1999-01-01

    Summarizes a Federal Ministry of Youth report on the conditions under which children grow up in Germany. Notes manifold problems that children face under today's living conditions. Presents recommendations and suggestions for providing a network of measures, relationships, and institutions to support children's development and education in family,…

  14. Determination of responses of growing pigs to

    African Journals Online (AJOL)

    1998-03-09

    Mar 9, 1998 ... The responses in growing pigs to balanced diets at different dietary energy levels are estimated from published data after recalculation of digestible energy (DE) iev- els using standard tables. Although responses in live weight gain (ADG), food intake (Fl), digestible energy intake (DEI) and food conversion ...

  15. How fast to northern hardwoods grow?

    Science.gov (United States)

    Rapheal Zon; H.F. Scholz

    1929-01-01

    The knowledge of the rate at which trees grow in virgin forests, after clear cutting and under selective logging, is indispensable in any forest calculations or forest practice. The enactment of the Forest Crop Law, which brought under its operation about 175,000 acres of cut-over land during the first year, the example set by several progressive lumbermen in selective...

  16. Growing Up in an Alcoholic Family.

    Science.gov (United States)

    Abbott, Stephanie

    1993-01-01

    Discusses problems faced by children growing up in an alcoholic family. Reviews four survivor roles of children of alcoholics (COAs): super-coper, scapegoat, lost child, and family mascot. Describes alcoholism as a disease of denial. Reviews the Children of Alcoholics movement begun by adult COAs to become advocates for COAs. (NB)

  17. Growing up as a Young Artist

    Science.gov (United States)

    Szekely, George

    2012-01-01

    "Growing Up as a Young Artist" is an illustrated book assignment that involves researching family scrapbooks, photo albums and films, and inquiring about family anecdotes for clues to one's artistic roots. Students creatively reflect on their early memories of imaginative events, as each page is filled with memories of creative activities they…

  18. Play Games to Grow up Bilingual

    DEFF Research Database (Denmark)

    Valente, Andrea; Marchetti, Emanuela

    2007-01-01

    A new kind of computer game is proposed, to support the linguistic development of primary school children, growing in multilingual environments: with it players will be able to simultaneously learn multiple languages. The novel idea is to treat words in different languages as physical items, that...

  19. Play Games to Grow up Bilingual

    DEFF Research Database (Denmark)

    Valente, Andrea; Marchetti, Emanuela

    2008-01-01

    A new kind of computer game is proposed, to support the linguistic development of primary school children, growing in multilingual environments: with it players will be able to simultaneously learn multiple languages. The novel idea is to treat words in different languages as physical items, that...

  20. Preliminary characterization of slow growing rhizobial strains ...

    African Journals Online (AJOL)

    In this paper, we did some preliminary characterization of six slow growing rhizobial strains, isolated from Retama monosperma (L.) Boiss. root nodules sampled from 3 sites along the coast of Oran (CapeFalcon, Bousfer and MersElHadjadj) in Northwestern Algeria. Results of this study showed that all strains had a very ...

  1. growing African giant rats Cricetomys gambianus

    African Journals Online (AJOL)

    Thermoregulation and evaporative water loss in growing African giant rats Cricetomys gambianus. M.H. Knight. Mammal Research Institute, University of Pretoria, Pretoria. With an increase in mass, weaned giant rat pups. Cricetomys gambianus, showed a corresponding decline in mass specific metabolism, conductance ...

  2. CARROT SEED GROWING THROUGH WINTERING SEEDLINGS

    Directory of Open Access Journals (Sweden)

    A. P. Zvedenuk

    2017-01-01

    Full Text Available The results of research work on carrot seed growing through wintering seedlings carried out at laboratory of seed studies and seed production of Transnistrian Research Institute of Agriculture, on the soil of the first terrace at the rive Dniester were presented in the article. Seed bearing plants of garden carrot ‘Krasavka’ were the object of the study. The seeds were sown to produce the seedlings on 15-16 August. In the first decade of December the plants were covered with white agrotextile with density 23g/m2 that was removed at the beginning of April. The proportion of plant that passed the winter depending on a year of cultivation was 95-100% under argotextile, and 50-80% in open plot. The plants under agrotextile reached 28 cm a high and had 5-7 well-developed leaves, while those on the open plot were at phase of active foliage growing about 10-13 cm. long. Thus, for early mechanized planting in optimal terms the wintering seedlings grown under agrotextile had the best biometrical characteristics. Moreover the outcome of carrot seedlings was 1.2-1.25 million per hectare. Such quantity of seedlings was sufficient to plant 9-10 ha of carrot plants, where the coefficient of multiplication reached 9-10, and only 3 when growing seeds through mother plant as biennial culture. Viability of seed plants grown through seedlings was 100%. Losses of plant with weight 120-150 grams from damage caused by diseases was 23%. The seed yield, when growing seedlings was 639 kg/ha, but growing through plants was 332 kg/ha. The seed outcome suitable for precise mechanized sowing through seedling growing was 77%, where seed germination was 90%, with seed fraction 1.51 and >2.0 mm. It was essentially improved their yielding characteristics. Seed outcome from this fraction obtained through planting method was 32%. The proportion of seeds in fraction 1-1.5 mm was 68%. For mechanized single-seed sowing, the seeds can be used only after mini-coating. The seed

  3. Learning Topologies with the Growing Neural Forest.

    Science.gov (United States)

    Palomo, Esteban José; López-Rubio, Ezequiel

    2016-06-01

    In this work, a novel self-organizing model called growing neural forest (GNF) is presented. It is based on the growing neural gas (GNG), which learns a general graph with no special provisions for datasets with separated clusters. On the contrary, the proposed GNF learns a set of trees so that each tree represents a connected cluster of data. High dimensional datasets often contain large empty regions among clusters, so this proposal is better suited to them than other self-organizing models because it represents these separated clusters as connected components made of neurons. Experimental results are reported which show the self-organization capabilities of the model. Moreover, its suitability for unsupervised clustering and foreground detection applications is demonstrated. In particular, the GNF is shown to correctly discover the connected component structure of some datasets. Moreover, it outperforms some well-known foreground detectors both in quantitative and qualitative terms.

  4. GenBank blastx search result: AK243491 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243491 J100073O14 M86823.1 RCANIFA Rhodobacter sphaeroides ORF1, complete cds; nif...U gene, complete cds; nifS gene, complete cds; nifV gene, complete cds; nifW gene, complete cds; rponN gene, partial cds. BCT 2e-36 1 ...

  5. GenBank blastx search result: AK060287 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK060287 001-006-C09 AF212163.1 Rhodobacter sphaeroides PduO (pduO), electron trans...fer flavoprotein B subunit (etfB), electron transfer flavoprotein subunit A (etfA), and S(+)-beta-hydroxybut

  6. GenBank blastx search result: AK061773 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK061773 001-039-D01 AF212163.1 Rhodobacter sphaeroides PduO (pduO), electron trans...fer flavoprotein B subunit (etfB), electron transfer flavoprotein subunit A (etfA), and S(+)-beta-hydroxybut

  7. Role of charge-transfer states in bacterial photosynthesis

    NARCIS (Netherlands)

    Meech, S.R.; Hoff, A.J.

    1986-01-01

    Photon echo, photon-echo excitation, and "hole-burning" data recorded in the 800-990 nm region of Rhodobacter sphaeroides R26 and Rhodopseudomonas viridis reaction centers are reported. The primary process in these reaction centers, following excitation, was found to occur in ≈25 fsec; the

  8. Chromophore composition of a heterologously expressed BLUF-domain.

    NARCIS (Netherlands)

    Laan, W.W.J.; Bednarz, T.; Heberle, J.; Hellingwerf, K.J.

    2004-01-01

    Upon heterologous expression of the BLUF (for: Blue-Light sensing Using Flavin) domain from AppA, a transcriptional anti-repressor from Rhodobacter sphaeroides, in Escherichia coli, photoactive holo-protein is formed through non-covalent binding of a flavin. Whereas it is generally assumed that FAD

  9. GenBank blastx search result: AK287500 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK287500 J043034C21 M86823.1 RCANIFA Rhodobacter sphaeroides ORF1, complete cds; nif...U gene, complete cds; nifS gene, complete cds; nifV gene, complete cds; nifW gene, complete cds; rponN gene, partial cds. BCT 7e-11 0 ...

  10. African Journal of Biotechnology - Vol 5, No 22 (2006)

    African Journals Online (AJOL)

    Poly-b-hydroxybutyrate accumulation and releasing by hydrogen producing bacteria, Rhodobacter sphaeroides O.U.001. A transmission electron microscopic study · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. D Çetin, U Gündüz, I Eroglu, M Yücel, L Türker ...

  11. Directed assembly of functional light harvesting antenna complexes onto chemically patterned surfaces

    NARCIS (Netherlands)

    Escalante Marun, M.; Maury, P.A.; Bruinink, C.M.; van der Werf, Kees; Olsen, John D.; Timney, A.; Huskens, Jurriaan; Hunter, C. Neil; Subramaniam, Vinod; Otto, Cornelis

    2008-01-01

    We report the directed assembly of the photosynthetic membrane proteins LH1 and LH2 isolated from the purple bacterium Rhodobacter sphaeroides onto chemically patterned substrates. Nanoimprint lithography was used to pattern discrete regions of amino- and fluoro-terminated or poly(ethylene glycol)

  12. Efficient Communication Management in a Growing Organisation

    OpenAIRE

    Alakotila, Susanna

    2017-01-01

    The purpose of this thesis is to analyse the importance of organisational communication and to explain how communication should be managed for it to be effective. Two fast-growing companies were interviewed for the thesis, who give entail on how they have managed communication regarding the organisational changes. Organisational communication is divided into external, stakeholder and internal communication in this study. With the help of interviews from two case companies, researcher offers r...

  13. Transformational Leadership Which Can Grow Organizational Commitment

    OpenAIRE

    Silalahi, Betty Yuliani

    2008-01-01

    A meta-analysis consist of 45 studies from 20 articles and 20860 subjects evaluated the correlation between Transformational leadership and Organizational commitment. Summary analysis provided support for the hypothesis that transformational leadership has a correlation on organizational commitment. The purpose of the study is to analyzed the data from the primer study and to support the hypothesis or refuse from the studies. Result indicated that transformational leadership can grow organiza...

  14. Shape of the growing front of biofilms

    Science.gov (United States)

    Wang, Xin; Stone, Howard A.; Golestanian, Ramin

    2017-12-01

    The spatial organization of bacteria in dense biofilms is key to their collective behaviour, and understanding it will be important for medical and technological applications. Here we study the morphology of a compact biofilm that undergoes unidirectional growth, and determine the condition for the stability of the growing interface as a function of the nutrient concentration and mechanical tension. Our study suggests that transient behaviour may play an important role in shaping the structure of a biofilm.

  15. Economic Gardening and the Grow Kentucky Program

    OpenAIRE

    Robbins, Lynn W.; Allen, James E. IV

    2015-01-01

    In 2014, the Community and Economic Development Initiative of Kentucky (CEDIK) and the Kentucky Small Business Development Center (KSBDC), launched Grow Kentucky, Kentucky’s only certified Economic Gardening program. The program helps second-stage entrepreneurial growth companies penetrate existing markets, identify new markets, monitor competitors, track industry trends, locate customer clusters, use search engine optimization/social media for marketing and various other customized research....

  16. Growing Role of Retail in Distribution Channels

    OpenAIRE

    Ishak Mesic

    2011-01-01

    This article aims to demonstrate the growing role of retail trade (retail) in the channels of distribution of goods both in domestic and international markets. Technical-technological development has provided great opportunities for all production of material goods, so that the focus of problem in the economic possibilities of playing shifted from production to sales opportunities, or consumption. The ultimate consumers and their needs and requirements have become a central area of study, bas...

  17. GRoW Buffalo Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Bohm, Martha [Univ. at Buffalo, NY (United States)

    2016-04-17

    This document provides final reporting on the GRoW Home, University at Buffalo's entry to the 2015 Solar Decathlon competition in Irvine, CA. The report summarizes fundraising efforts, documents media outreach, lists online presence, analyzes the organizer's communication, describes post-competition life of the house and future employment plans for student team members. Last, it suggests improvements for future decathlons.

  18. Exposure to vibrations in wine growing

    Directory of Open Access Journals (Sweden)

    Domenico Pessina

    2013-09-01

    Full Text Available Apart the winter period, the activity in specialized agricultural cultivations (i.e. wine- and fruit-growing is distributed for a long period of the year. Some tasks, such as pesticide distribution, are repeated several times during the growing season. On the other hand, mechanization is one of the pillars on which is based the modern agriculture management. As a consequence, in wine growing the tractor driver has to be considered a worker potentially subjected to high level of vibrations, due to the poor machinery conditions often encountered, and sometimes to the rough soil surface of the vineyard combined with the high travelling speed adopted in carrying out many operations. About vibrations, the Italian Decree 81/08 basically refers to the European Directive 2002/44/CE, that provides some very strict limits of exposure, both for whole body and hand-arm districts. In Oltrepo pavese, a large hilly area located the south part of the Pavia province (Lombardy - Italy wine growing is the main agricultural activity; for this reason, a detailed survey on the vibration levels recorded at the tractor driver’s seat was carried out, in order to ascertain the real risk to which the operators are exposed. The activity in wine growing has been classified into 6 groups of similar tasks, as follows: 1. canopy management: pruning, trimming, binding, stripping, etc.; 2. soil management: harrowing, hoeing, subsoiling etc.; 3. inter-row management: chopping of pruning , pinching, grass mowing, etc.; 4. crop protection: pesticides and fungicides distribution, sulfidation, foliar fertilization, etc.; 5. grape harvesting: manual or mechanical; 6. transport: from the vineyard to the cellar. For each group of tasks, the vibration levels on 3 the traditional axes (x, y and z were recorded, and then an exposure time was calculated for each of them, in order to ascertain the risk level in comparison to what provided by the dedicated standard. Finally, a detailed

  19. Growing media constituents determine the microbial nitrogen conversions in organic growing media for horticulture.

    Science.gov (United States)

    Grunert, Oliver; Reheul, Dirk; Van Labeke, Marie-Christine; Perneel, Maaike; Hernandez-Sanabria, Emma; Vlaeminck, Siegfried E; Boon, Nico

    2016-05-01

    Vegetables and fruits are an important part of a healthy food diet, however, the eco-sustainability of the production of these can still be significantly improved. European farmers and consumers spend an estimated €15.5 billion per year on inorganic fertilizers and the production of N-fertilizers results in a high carbon footprint. We investigated if fertilizer type and medium constituents determine microbial nitrogen conversions in organic growing media and can be used as a next step towards a more sustainable horticulture. We demonstrated that growing media constituents showed differences in urea hydrolysis, ammonia and nitrite oxidation and in carbon dioxide respiration rate. Interestingly, mixing of the growing media constituents resulted in a stimulation of the function of the microorganisms. The use of organic fertilizer resulted in an increase in amoA gene copy number by factor 100 compared to inorganic fertilizers. Our results support our hypothesis that the activity of the functional microbial community with respect to nitrogen turnover in an organic growing medium can be improved by selecting and mixing the appropriate growing media components with each other. These findings contribute to the understanding of the functional microbial community in growing media and its potential role towards a more responsible horticulture. © 2016 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  20. Nurturing a growing field: Computers & Geosciences

    Science.gov (United States)

    Mariethoz, Gregoire; Pebesma, Edzer

    2017-10-01

    Computational issues are becoming increasingly critical for virtually all fields of geoscience. This includes the development of improved algorithms and models, strategies for implementing high-performance computing, or the management and visualization of the large datasets provided by an ever-growing number of environmental sensors. Such issues are central to scientific fields as diverse as geological modeling, Earth observation, geophysics or climatology, to name just a few. Related computational advances, across a range of geoscience disciplines, are the core focus of Computers & Geosciences, which is thus a truly multidisciplinary journal.

  1. Parallelized seeded region growing using CUDA.

    Science.gov (United States)

    Park, Seongjin; Lee, Jeongjin; Lee, Hyunna; Shin, Juneseuk; Seo, Jinwook; Lee, Kyoung Ho; Shin, Yeong-Gil; Kim, Bohyoung

    2014-01-01

    This paper presents a novel method for parallelizing the seeded region growing (SRG) algorithm using Compute Unified Device Architecture (CUDA) technology, with intention to overcome the theoretical weakness of SRG algorithm of its computation time being directly proportional to the size of a segmented region. The segmentation performance of the proposed CUDA-based SRG is compared with SRG implementations on single-core CPUs, quad-core CPUs, and shader language programming, using synthetic datasets and 20 body CT scans. Based on the experimental results, the CUDA-based SRG outperforms the other three implementations, advocating that it can substantially assist the segmentation during massive CT screening tests.

  2. Growing Quality in Qualitative Health Research

    Directory of Open Access Journals (Sweden)

    Mary Ellen Macdonald PhD

    2009-06-01

    Full Text Available Qualitative methodologies are growing in popularity in health research; however, the integration of these methodologies into the clinical context is not always straightforward. In this article the author discusses some of the paradigmatic and methodological tensions that characterize the use of qualitative methodologies in clinical health research and showcase one solution to these tensions. The McGill Qualitative Health Research Group is a scholarly group of qualitative health researchers working together to advance a qualitative research agenda in clinical disciplines.

  3. Mapping Nutrients Crucial to a Growing Population

    Science.gov (United States)

    Tarnowski, J. R.; Cassidy, E. S.; Gerber, J. S.

    2011-12-01

    Over two billion people worldwide suffer from inadequate levels of micronutrients, mainly in the form of iodine, iron, and vitamin A deficiencies. With a growing population, producing crops that contain high amounts of these micronutrients is of increased importance. Addressing these deficiencies sustainably requires a detailed examination of the agricultural production of the micronutrients. The purpose of this study is to determine whether or not enough of these important nutrients are produced to meet the nutritional needs of the global population, and to determine where nutrients are most deficient. We used area specific crop production data to map where and how much iron and vitamin A are produced from major crops.

  4. Growing in darkness: The etiolated lupin hypocotyls

    OpenAIRE

    Sánchez-Bravo, José; Oliveros-Valenzuela, M Rocío; Nicolás, Carlos; Acosta, Manuel

    2008-01-01

    Epigeal germination of a dicot, like lupin (Lupinus albus L.), produces a seedling with a characteristic hypocotyl, which grows in darkness showing a steep growth gradient with an elongation zone just below the apex. The role of phytohormones, such as auxin and ethylene, in etiolated hypocotyl growth has been the object of our research for some time. The recent cloning and expression of three genes of influx and efflux carriers for polar auxin transport (LaAUX1, LaPIN1 and LaPIN3) reinforces ...

  5. Biofilm-growing intestinal anaerobic bacteria.

    Science.gov (United States)

    Donelli, Gianfranco; Vuotto, Claudia; Cardines, Rita; Mastrantonio, Paola

    2012-07-01

    Sessile growth of anaerobic bacteria from the human intestinal tract has been poorly investigated, so far. We recently reported data on the close association existing between biliary stent clogging and polymicrobial biofilm development in its lumen. By exploiting the explanted stents as a rich source of anaerobic bacterial strains belonging to the genera Bacteroides, Clostridium, Fusobacterium, Finegoldia, Prevotella, and Veillonella, the present study focused on their ability to adhere, to grow in sessile mode and to form in vitro mono- or dual-species biofilms. Experiments on dual-species biofilm formation were planned on the basis of the anaerobic strains isolated from each clogged biliary stent, by selecting those in which a couple of anaerobic strains belonging to different species contributed to the polymicrobial biofilm development. Then, strains were investigated by field emission scanning electron microscopy and confocal laser scanning microscopy to reveal if they are able to grow as mono- and/or dual-species biofilms. As far as we know, this is the first report on the ability to adhere and form mono/dual-species biofilms exhibited by strains belonging to the species Bacteroides oralis, Clostridium difficile, Clostridium baratii, Clostridium fallax, Clostridium bifermentans, Finegoldia magna, and Fusobacterium necrophorum. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  6. Tracheotomy in growing rats: histological aspects

    Directory of Open Access Journals (Sweden)

    Manna Mônica Cecília Bochetti

    2003-01-01

    Full Text Available PURPOSE: To compare morphologically three different types of tracheotomy in growing rats, applying microsurgical technique. METHODS: EPM-1 Wistar growing rats (n=57 weighing 88gm and aged 35 days were randomized in four groups, according tracheotomy incision type (longitudinal, transverse and tracheal segment excision, and sham group. Following intramuscular anesthesia with ketamine and xylazine, the trachea was exposed and incised, according to the group, and a hand-made endotracheal cannula was inserted into the organ, under sterile conditions. This cannula was removed after 7 days, and animals have been sacrificed 30 days later. Tracheas samples were submitted to histological study, stained by hematoxylin-eosin and Masson trichrome, evaluating fibrosis, inflammatory infiltrate and epidermoid metaplasia. RESULTS: There was more frequency of inflammatory infiltrate at the tracheal epithelium in the tracheal segment excision group (87% compared to the longitudinal (40% and transverse (36% incision groups (p=0.009. Evaluating epidermoid metaplasia, tracheal segment excision and the longitudinal groups presented 33% and 40%, respectively, compared to 0% of the transverse group (p=0.03. Concerning to fibrosis, in a global comparison (p=0.1 among the three groups there was no difference, however, compared to the longitudinal group the transverse group showed lower level of fibrosis (p=0.04. Sham group did not present any relevant morphologic alterations and it was used as reference pattern. CONCLUSION: Taken together, our data show that tracheal segment excision promotes more epithelium aggression and transverse tracheal incision shows less morphologic alterations.

  7. Immunotoxicity of ochratoxin A to growing gilts.

    Science.gov (United States)

    Harvey, R B; Elissalde, M H; Kubena, L F; Weaver, E A; Corrier, D E; Clement, B A

    1992-10-01

    Ochratoxin A (OA) was incorporated in the diets of growing gilts (mean body weight, 20.1 kg) at a concentration of 2.5 mg of OA/kg of feed and was fed continuously for 35 days. Humoral and cell-mediated immunologic measurements were evaluated to determine the effects of OA on immune function in swine. Cutaneous basophil hypersensitivity to phytohemagglutinin (PHA), delayed hypersensitivity to tuberculin, PHA-induced lymphocyte blastogenesis, interleukin-2 production, total and isotype immunoglobulin concentrations, antibody response to chicken RBC, and macrophage activation were used to evaluate immune function. Gilts treated with OA had reduced cutaneous basophil hypersensitivity response to PHA, reduced delayed hypersensitivity to tuberculin, decreased stimulation index for lymphoblastogenesis, decreased interleukin-2 production when lymphocytes were stimulated with concanavalin A, and decreased number and phagocytic activity of macrophages. Differences were not observed for total and isotype immunoglobulin concentrations, or humoral hemagglutination (chicken RBC) titer. These data indicate that OA may suppress cell-mediated immune response in growing swine.

  8. Light colour preference of growing rabbits

    Directory of Open Access Journals (Sweden)

    Zsolt Szendrő

    2010-01-01

    Full Text Available The objective of the experiment was to evaluate the light colour preference of growing rabbits placed in a free-choice cage. The experiment was carried out on 128 Pannon White growing rabbits weaned at the age of 5 weeks and placed into blocks (2m2 of four cages. The rabbits could move freely among the four cages (0.5m2 each through swing doors. The cages differed only in the colour of the light applied (white, yellow, green or blue. The lighting schedule was 16L: 8D. From 6 until 10 weeks of age, infrared video recording was performed once a week (24 hours. The number of rabbits in each cage was counted every 15 minutes. Feed consumption was measured weekly. Between 6 and 10 weeks of age the rabbits significantly preferred white light (28.0%. The preference order was the following: yellow (26.3%, blue (23.4% and green (22.3% (P<0.001. No significant differences were recorded in the feed consumption among the cages. In conclusion, the cage preference of the rabbits was slightly affected by the light colour.

  9. Management of Infections with Rapidly Growing

    Directory of Open Access Journals (Sweden)

    Jong Hwan Kim

    2012-01-01

    Full Text Available Background Infection caused by rapidly growing mycobacteria (RGM is not uncommon, andthe prevalence of RGM infection has been increasing. Clinical diagnosis is difficult becausethere are no characteristic clinical features. There is also no standard antibiotic regimenfor treating RGM infection. A small series of patients with RGM infections was studied toexamine their treatments and outcomes.Methods A total of 5 patients who had developed postoperative infections from January2009 to December 2010 were retrospectively reviewed. Patients were initially screened using amycobacteria rapid screening test (polymerase chain reaction [PCR]-reverse blot hybridizationassay. To confirm mycobacterial infection, specimens were cultured for nontuberculousmycobacteria and analyzed by 16 S ribosomal RNA and rpoB gene PCR.Results The patients were treated with intravenous antibiotics during hospitalization,and oral antibiotics were administered after discharge. The mean duration of follow-upwas 9 months, and all patients were completely cured of infection with a regimen of acombination of antibiotics plus surgical treatment. Although none of the patients developedrecurrence, there were complications at the site of infection, including hypertrophic scarring,pigmentation, and disfigurement.Conclusions Combination antibiotic therapy plus drainage of surgical abscesses appeared tobe effective for the RGM infections seen in our patients. Although neither the exact dosagenor a standardized regimen has been firmly established, we propose that our treatment canprovide an option for the management of rapidly growing mycobacterial infection.

  10. Elastic plastic analysis of growing cracks

    Energy Technology Data Exchange (ETDEWEB)

    Rice, J R; Drugan, W J; Sham, T L

    1979-05-01

    The elastic--plastic stress and deformation fields at the tip of a crack which grows in an ideally plastic solid under plane strain, shows small scale yielding conditions. Results of an asymptotic analysis suggests the existence of a crack tip stress state similar to that of the classical Prandtl field, but containing a zone of elastic unloading between the centered fan region and the trailing constant stress plastic region. The near tip expression for the rate of opening displacement delta at distance r from the growing tip is found to have the form delta-. = ..cap alpha.. J-./sigma/sub o/ + ..beta..(sigma/sub o//E) a-. ln(R/r) but the presence of the elastic wedge causes ..beta.. to have the revised value of 5.08 (for Poisson ratio ..nu.. = 0.3); also, (a = crack length, sigma/sub o/ = yield strength, E = elastic modulus, and J denotes the far-field value), and (1-..nu../sup 2/)K/sup 2//E for the small scale yielding conditions considered. The parameters ..cap alpha.. and R cannot be determined from the asymptotic analysis, but comparisons with finite element solutions suggest that, for small amounts of growth, ..cap alpha.. is approximately the same for stationary and growing cracks, and R scales approximately with the size of the plastic zone, being about 15% to 30% larger. For large scale yielding, a similar form applies with possible variations in ..cap alpha.. and ..beta.., in cases which maintain triaxial constraint at the crack tip. In the fully yielded case R is expected to be proportional to the dimension of the uncracked ligament. Model crack growth criterion requiring a critical delta at some fixed r from the tip, is re-examined in light of the more accurate solution. Results suggest that the J versus ..delta..a relation describing growth is dependent on the extent of yielding. It is suggested that this dependency might be small for highly ductile materials, provided that a similar triaxial constraint is maintained in all cases.

  11. Dietary supplementation of butyrate in growing rabbits

    Directory of Open Access Journals (Sweden)

    G. Radaelli

    2010-01-01

    Full Text Available The UE restrictions imposed on the antibiotic utilization in animal husbandry have increased the interest on alternative additives capable of improving animal digestive health. Among the numerous tested products, short chain fatty acids stimulated intestinal mucus production at different level and intestinal cells proliferation in rats (Meslin et al., 2001; Moreau et al., 2003. Short and medium chain fatty acids could also modulate intestinal microflora: in rabbits, the antimicrobial activity of caprilic and capric acids was proved on various strains of Clostridium perfringens and Escherichia coli (Marounek et al., 2002. The present trial aimed to evaluate the effect of butyrate inclusion and level on growth performance, health status, digestive physiology and slaughter traits in growing rabbits.

  12. Morphogenesis of filaments growing in flexible confinements

    Science.gov (United States)

    Vetter, R.; Wittel, F. K.; Herrmann, H. J.

    2014-07-01

    Space-saving design is a requirement that is encountered in biological systems and the development of modern technological devices alike. Many living organisms dynamically pack their polymer chains, filaments or membranes inside deformable vesicles or soft tissue-like cell walls, chorions and buds. Surprisingly little is known about morphogenesis due to growth in flexible confinements—perhaps owing to the daunting complexity lying in the nonlinear feedback between packed material and expandable cavity. Here we show by experiments and simulations how geometric and material properties lead to a plethora of morphologies when elastic filaments are growing far beyond the equilibrium size of a flexible thin sheet they are confined in. Depending on friction, sheet flexibility and thickness, we identify four distinct morphological phases emerging from bifurcation and present the corresponding phase diagram. Four order parameters quantifying the transitions between these phases are proposed.

  13. THE FASTEST GROWING LEAST DEVELOPED COUNTRIES

    Directory of Open Access Journals (Sweden)

    Wioletta NOWAK

    2017-12-01

    Full Text Available The paper presents trends in economic growth and development in twelve least developed countries from 2006 to 2015. The study is based on the data retrieved from the World Bank Database. During the analysed 10 years, seven Asian (Myanmar, Lao PDR, Bhutan, Cambodia, Timor-Leste, Bangladesh, and Afghanistan and five African (Ethiopia, Rwanda, Angola, Sudan, and Mozambique LDCs had average annual GDP per capita growth rates higher than 4.0%. GDP has been largely generated through the services and industry sectors. A few LDCs sustained strong growth mainly because of foreign assistance and in other countries remittances were a significant source of development finance. Resource rich countries recorded high inflows of foreign direct investment. In a few fast growing LDCs the state has been heavily engaged in economy. The analysed LDCs substantially improved their development indicators.

  14. Feed efficiency metrics in growing pigs.

    Science.gov (United States)

    Calderón Díaz, J A; Berry, D P; Rebeiz, N; Metzler-Zebeli, B U; Magowan, E; Gardiner, G E; Lawlor, P G

    2017-07-01

    The objective of the present study was to quantify the interrelationships between different feed efficiency measures in growing pigs and characterize pigs divergent for a selection of these measures. The data set included data from 311 growing pigs between 42 and 91 d of age from 3 separate batches. Growth-related metrics available included midtest metabolic BW (BW), energy intake (EI), and ADG. Ratio efficiency traits included energy conversion ratio (ECR), Kleiber ratio (ADG/BW), relative growth rate (RGR), residual EI (REI), and residual daily gain (RDG). Residual intake and gain (RIG; i.e., a dual index of both REI and RDG) and residual midtest metabolic weight (RMW) were also calculated. Simple Pearson correlations were estimated between the growth and feed efficiency metrics. In litters with at least 3 pigs of each sex, pigs were separately stratified on each residual trait as high, medium, and low rank. Considerable interanimal variability existed in all metrics evaluated. Male pigs were superior to females for all metrics ( efficiency metrics improved as birth BW increased ( efficiency metrics were strong to moderate ( efficient) had lower EI and ECR and were superior for RIG ( efficient) had greater BW gain and better ECR ( Energy conversion ratio, REI, and RIG were superior ( efficient) compared with medium-RMW pigs. High-RIG pigs (i.e., more efficient) had lower EI ( efficiency traits investigated in this study were different from unity, indicating that each trait is depicting a different aspect of efficiency in pigs, although the moderate to strong correlations suggest that improvement in one trait would, on average, lead to improvements in the others. Pigs ranked as more efficient on residual traits such as REI consumed less energy for a similar BW gain, which would translate into an economic benefit for pig producers.

  15. CO2 reduction and organic compounds production by photosynthetic bacteria with surface displayed carbonic anhydrase and inducible expression of phosphoenolpyruvate carboxylase.

    Science.gov (United States)

    Park, Ju-Yong; Kim, Yang-Hoon; Min, Jiho

    2017-01-01

    In Rhodobacter sphaeroides, carbonic anhydrase (CA; EC 4.2.1.1) is a zinc-containing metalloenzyme that catalyzes the reversible hydration of CO2 to HCO3- while phosphoenolpyruvate carboxylase (PEPC; 4.1.1.31), an enzyme involved in the carbon metabolism that catalyzed the fixation of CO2 to PEP, is a key factor for biological fixation of CO2 and enhances the production of organic compounds. In this study, the recombinant R. sphaeroides with highly-expressed CA was developed based on a surface displayed system of CA (pJY-OmpCA) on the outer membrane of R. sphaeroides using outer membrane protein (Omp) in R. sphaeroides, Finally, two more different recombinant R. sphaeroides were developed, which transformed with a two-vector system harboring cytosolic expressed CA (pJY-OmpCA-CA)or PEPC (pJY-OMPCA-PEPC) in R. sphaeroides with surface displayed CA on the outer membrane. In case of recombinant R. sphaeroides with the pJY-OmpCA-PEPC, it has shown the highest CO2 reduction efficiency and the production of several organic compounds (carotenoids, polyhydroxybutyrate, malic acid, succinic acid). It means that the surface displayed CA on the R. sphaeroides would accelerate the CO2-bicabonate conversion on the bacterial outer membrane. Moreover, inducible over-expression of PEPC with surface-displayed CA was successfully used to facilitate a rapider CO2 reduction and quicker production of organic compounds. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Segregation of chromosome arms in growing and non-growing Escherichia coli cells

    DEFF Research Database (Denmark)

    Woldringh, Conrad L.; Hansen, Flemming G.; Vischer, Norbert O. E.

    2015-01-01

    In slow-growing Escherichia coli cells the chromosome is organized with its left (L) and right (R) arms lying separated in opposite halves of the nucleoid and with the origin (0) in-between, giving the pattern L-O-R. During replication one of the arms has to pass the other to obtain the same...

  17. Growing Youth Growing Food: How Vegetable Gardening Influences Young People's Food Consciousness and Eating Habits

    Science.gov (United States)

    Libman, Kimberly

    2007-01-01

    Much attention is currently being paid to rising rates of obesity, especially among youth. In this context, garden-based education can have a role in improving public health. A qualitative study conducted at the Brooklyn Botanic Garden (BBG) Children's Garden provides supporting evidence for the claim that growing vegetables can improve the…

  18. Wartime diet for growing bobwhite quail

    Science.gov (United States)

    Nestler, R.B.; Llewellyn, L.; Benner, M.

    1944-01-01

    Two experiments, using 784 bobwhite quail chicks, were conducted at the Patuxent Research Refuge, Bowie, Maryland, to find a growing diet that would meet wartime restrictions. In 1941 a diet containing 14 per cent sardine fish meal was formulated and gave satisfactory results from the standpoints of survival and growth. Since fish meal now is scarce, search was made for a diet without war-restricted commodities yet equal to the above-mentioned diet in feeding value. Ten diets were compared.....In the present experiments, quail fed this same diet modified by the substitution of 0.12 per cent of D-activated sterol for vitamin A and D feeding oil fortified showed the highest survival and the best live weights at the end of both the sixth and tenth weeks. They also were among the top three groups in requiring the least quantity of feed per unit of gain in weight; however, they consumed the greatest quantity of feed.....Of the other nine diets, that which seemed most promising, considering survival, live weight, and efficiency of feed utilization, was as follows (parts by weight) : Yellow corn, ground 26.08...Millet, ground 10.00...Alfalfa leaf meal, dehydrated 7.50...Soybean oil meal, solvent-processed 50.00...Dried whey 3.00...Special steamed bonemeal 1.50...Limestone, ground 0.80...Salt mixture 1.OO...D-activated animal sterol 0.12....100.00.....At the end of ten weeks the results on this diet (Diet l l ) , as compared with that containing sardine meal (Diet 23), were as follows: Diet No. 11 Percentage survival 71, Average live weight per bird, grams 144,....Growing mash consumed, per bird-day, grams 6.8 Feed consumed per gram of gain in weight (grams) 3.8......Diet 23....Percentage survival, 80,...Avg live weight per bird, grams....145,....Growing mash consumed , per bird-day, grams...7.4...Feed consumed per gram of gain in weight (grams)....3.9. Results were unsatisfactory when expeller-processed soybean oil meal was used in this diet to replace solvent

  19. Growing pains: twelve lessons from corporate restructuring.

    Science.gov (United States)

    Gill, S L; Johnson, R L

    1988-05-01

    Corporate reorganization is a realignment of resources to enhance competitive strength and can follow one of two lines, vertical or horizontal. Whichever strategy is used, the reason for it remains unchanged: to provide a structural hierarchy through which strategic market niches are acquired and resources are economically deployed throughout the system. Healthcare corporate restructuring, however, is encountering growing pains, some of which were inevitable and others avoidable. When the healthcare organizational landscape is surveyed, 12 lessons can be learned about corporate reorganization: 1. Reorganization should be based on anticipated market and environmental conditions. 2. Form follows function. 3. Interdependence among multiple corporate units must be clearly acknowledged. 4. Reorganization is much more costly and politically charged than it appears at first. Reserved rights must be clearly defined. 6. The purpose and composition of the parent governing board must be distinguished from those of subsidiary boards. 7. Clarification of roles and relationships between the parent and subsidiaries is critical. 8. Unrealistic expectations of success should be confronted through up-front planning, negotiation, and creative problem solving. 9. False assumptions about corporate staffing needs create internal system warfare. 10. Physician support is crucial for success. 11. Hospital-based management skills and understanding may be inadequate for making personnel decisions in subsidiaries other than the hospital. 12. Competitive strategies must be strategically determined and must not be taken gamesmanship.

  20. Autoethnography in Health Research: Growing Pains?

    Science.gov (United States)

    Chang, Heewon

    2016-03-01

    Autoethnography is gaining acceptance as a legitimate research method in health science research. The growing volume of published autoethnographies is indicative of this trend. After discussing the methodological tenents of this qualitative research method and its compatibility with health-related research, the author illustrates this trend with examples of published autoethnogrpahic books, theses, and journal articles. While celebrating the potential of autoethnography as a suitable health research method, the author critiques dominatly descriptive and evocative illness self-narratives that may evoke emontionally compelling responses from readers but offer insufficient sociocultural insights about the illness phenomenon. To identify a "desirable" autoethnography that provides not only a "thick description" of personal experiences but also a sociocultural interpration of such experiences, the author recommends both creators and consumers of autoethnography to ask five evaluative questions: (1) Does the autoethnography use authentic and trustworthy data?; (2) Does the autoethnography follow a reliable research process and show the process clearly?; (3) Does the autoethnography follow ethical steps to protect the rights of self and others presented and implicated in the autoethnography?; (4) Does the autoethnography analyze and interpret the sociocultural meaning of the author's personal experiences?; and (5) Does the autoethnography attempt to make a scholarly contribution with its conclusion and engagement of the existing literature? © The Author(s) 2016.

  1. Growing duckweed for biofuel production: a review.

    Science.gov (United States)

    Cui, W; Cheng, J J

    2015-01-01

    Duckweed can be utilised to produce ethanol, butanol and biogas, which are promising alternative energy sources to minimise dependence on limited crude oil and natural gas. The advantages of this aquatic plant include high rate of nutrient (nitrogen and phosphorus) uptake, high biomass yield and great potential as an alternative feedstock for the production of fuel ethanol, butanol and biogas. The objective of this article is to review the published research on growing duckweed for the production of the biofuels, especially starch enrichment in duckweed plants. There are mainly two processes affecting the accumulation of starch in duckweed biomass: photosynthesis for starch generation and metabolism-related starch consumption. The cost of stimulating photosynthesis is relatively high based on current technologies. Considerable research efforts have been made to inhibit starch degradation. Future research need in this area includes duckweed selection, optimisation of duckweed biomass production, enhancement of starch accumulation in duckweeds and use of duckweeds for production of various biofuels. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  2. Adult congenital heart disease: a growing epidemic.

    Science.gov (United States)

    Ávila, Pablo; Mercier, Lise-Andrée; Dore, Annie; Marcotte, François; Mongeon, François-Pierre; Ibrahim, Reda; Asgar, Anita; Miro, Joaquim; Andelfinger, Gregor; Mondésert, Blandine; de Guise, Pierre; Poirier, Nancy; Khairy, Paul

    2014-12-01

    Medical and surgical breakthroughs in the care of children born with heart defects have generated a growing population of adult survivors and spawned a new subspecialty of cardiology: adult congenital heart disease. The prevalence of adult congenital heart disease is escalating at a rampant rate, outpacing the relatively static prevalence of pediatric congenital heart disease, because adults now surpass children in numbers by a ratio of 2:1. As such, congenital heart disease can no longer be considered primarily a pediatric specialty. Most congenital heart defects are not curable and require lifelong specialized care. Health care systems worldwide are challenged to meet the unique needs of this increasingly complex patient population, including the development of supraregional centres of excellence to provide comprehensive and multidisciplinary specialized care. In this review, we explore the incidence and prevalence of congenital heart disease and their changing patterns, address organization and delivery of care, highlight the importance of appropriate training and dedicated research, summarize the high burden of health care resource utilization, and provide an overview of common issues encountered in adults with congenital heart disease. Copyright © 2014 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  3. Bioaugmentation in growing plants for lunar bases

    Science.gov (United States)

    Zaets, I.; Burlak, O.; Rogutskyy, I.; Vasilenko, A.; Mytrokhyn, O.; Lukashov, D.; Foing, B.; Kozyrovska, N.

    2011-03-01

    Microorganisms may be a key element in a precursory scenario of growing pioneer plants for extraterrestrial exploration. They can be used for plant inoculation to leach nutritional elements from regolith, to alleviate lunar stressors, as well as to decompose both lunar rocks and the plant straw in order to form a protosoil. Bioleaching capacities of both French marigold (Tagetes patula L.) and the associated bacteria in contact with a lunar rock simulant (terrestrial anorthosite) were examined using the model plant-bacteria microcosms under controlled conditions. Marigold accumulated K, Na, Fe, Zn, Ni, and Cr at higher concentrations in anorthosite compared to the podzol soil. Plants inoculated with the consortium of well-defined species of bacteria accumulated higher levels of K, Mg, and Mn, but lower levels of Ni, Cr, Zn, Na, Ca, Fe, which exist at higher levels in anorthosite. Bacteria also affected the Са/Mg and Fe/Mn ratios in the biomass of marigold grown on anorthosite. Despite their growth retardation, the inoculated plants had 15% higher weight on anorthosite than noninoculated plants. The data suggest that the bacteria supplied basic macro-and microelements to the model plant.

  4. Growing Bacteriophage M13 in Liquid Culture.

    Science.gov (United States)

    Green, Michael R; Sambrook, Joseph

    2017-11-01

    Stocks of bacteriophage M13 are usually grown in liquid culture. The infected bacteria do not lyse but, instead, grow at a slower than normal rate to form a dilute suspension. The inoculum of bacteriophage is almost always a freshly picked plaque or a suspension of bacteriophage particles obtained from a single plaque, as described here. Infected cells contain up to 200 copies of double-stranded, replicative-form DNA and extrude several hundred bacteriophage particles per generation. Thus, a 1-mL culture of infected cells can produce enough double-stranded viral DNA (1-2 mg) for restriction mapping and recovery of cloned DNA inserts and sufficient single-stranded DNA (∼5-10 mg) for site-directed mutagenesis, DNA sequencing, or synthesis of radiolabeled probes. The titer of bacteriophages in the supernatant from infected cells is so high (∼10(12) pfu/mL) that a small aliquot serves as a permanent stock of the starting plaque. © 2017 Cold Spring Harbor Laboratory Press.

  5. The Growing Regulation of Conversion Therapy.

    Science.gov (United States)

    Drescher, Jack; Schwartz, Alan; Casoy, Flávio; McIntosh, Christopher A; Hurley, Brian; Ashley, Kenneth; Barber, Mary; Goldenberg, David; Herbert, Sarah E; Lothwell, Lorraine E; Mattson, Marlin R; McAfee, Scot G; Pula, Jack; Rosario, Vernon; Tompkins, D Andrew

    2016-01-01

    Conversion therapies are any treatments, including individual talk therapy, behavioral (e.g. aversive stimuli), group therapy or milieu (e.g. "retreats or inpatient treatments" relying on all of the above methods) treatments, which attempt to change an individual's sexual orientation from homosexual to heterosexual. However these practices have been repudiated by major mental health organizations because of increasing evidence that they are ineffective and may cause harm to patients and their families who fail to change. At present, California, New Jersey, Oregon, Illinois, Washington, DC, and the Canadian Province of Ontario have passed legislation banning conversion therapy for minors and an increasing number of US States are considering similar bans. In April 2015, the Obama administration also called for a ban on conversion therapies for minors. The growing trend toward banning conversion therapies creates challenges for licensing boards and ethics committees, most of which are unfamiliar with the issues raised by complaints against conversion therapists. This paper reviews the history of conversion therapy practices as well as clinical, ethical and research issues they raise. With this information, state licensing boards, ethics committees and other regulatory bodies will be better able to adjudicate complaints from members of the public who have been exposed to conversion therapies.

  6. Gasification research on wood grow project

    Energy Technology Data Exchange (ETDEWEB)

    Flanigan, V J

    1981-01-09

    The GROW (Gasification Research on Wood) project consists of a research project on thermochemical degradation of wood particles (sawdust or hammermilled wood) on a pilot plant scale and utilizes a 100 cm (40 in.) diameter fluidized sand bed reactor at capacities of up to 1000 Kg/Hr (2200 lb/hr). Supplementary facilities include wood preparation and air conveying, a wood feed bin, feed and transfer screws, an air compressor with storage and filter tanks, an electrical preheater, a propane-fired preheater, a cyclone separator removing solids from product gas, a water scrubber to cool and clean product gas, a scrubber wate settling tank, a scrubber water cooler, a knockout drum, a demister to be installed in the future, a recycle compressor for recirculation, a recycle gas storage tank, a flare and stack with air blower to dispose of the gas, 2 CO/sub 2/ stripper columns to be installed in the future to remove CO/sub 2/ by caustic adsorption, caustic tanks, and the necessary piping, pumps, sampling, and measurement facilities. A brief report of progress on the project is given, followed by the safety implementation plan and operating, maintenance, and safety procedures. (MHR)

  7. Turkey opens electricity markets as demand grows

    Energy Technology Data Exchange (ETDEWEB)

    McKeigue, J.; Da Cunha, A.; Severino, D. [Global Business Reports (United States)

    2009-06-15

    Turkey's growing power market has attracted investors and project developers for over a decade, yet their plans have been dashed by unexpected political or financial crises or, worse, obstructed by a lengthy bureaucratic approval process. Now, with a more transparent retail electricity market, government regulators and investors are bullish on Turkey. Is Turkey ready to turn the power on? This report closely examine Turkey's plans to create a power infrastructure capable of providing the reliable electricity supplies necessary for sustained economic growth. It was compiled with on-the-ground research and extensive interview with key industrial and political figures. Today, hard coal and lignite account for 21% of Turkey's electricity generation and gas-fired plants account for 50%. The Alfin Elbistan-B lignite-fired plant has attracted criticism for its lack of desulfurization units and ash dam facilities that have tarnished the industry's image. A 1,100 MW hard-coal fired plant using supercritical technology is under construction. 9 figs., 1 tab.

  8. Antimicrobial susceptibility testing in biofilm‐growing bacteria

    National Research Council Canada - National Science Library

    Macià, M. D; Rojo‐Molinero, E; Oliver, A

    2014-01-01

    .... The lack of correlation between conventional susceptibility test results and therapeutic success in chronic infections is probably a consequence of the use of planktonically growing instead of biofilm‐growing bacteria...

  9. Growing skull fracture stages and treatment strategy.

    Science.gov (United States)

    Liu, Xue-Song; You, Chao; Lu, Ma; Liu, Jia-Gang

    2012-06-01

    A growing skull fracture (GSF) is a rare but significant late complication of skull fractures, usually occurring during infancy and early childhood. Delayed diagnosis and improper treatment could exacerbate this disease. The aim of this study was to introduce a new hypothesis about, describe the stages of, and discuss the treatment strategy for GSF. The authors performed a retrospective review of 27 patients with GSF, who were grouped according to 3 different GSF stages. Over a period of 20 years, 27 patients with GSF (16 males and 11 females) were treated in the authors' department. The mean follow-up period was 26.5 months. Six patients were in the prephase of GSF (Stage 1), 10 patients in the early phase (Stage 2), and 11 in the late phase (Stage 3). All patients underwent duraplasty. All 6 patients at Stage 1 and 5 patients at Stage 2 underwent craniotomy without cranioplasty. Five patients at Stage 2 and all of the patients at Stage 3 underwent cranioplasty with autologous bone and alloplastic materials, respectively. Among all patients, 5 underwent ventriculoperitoneal shunt placement. Symptoms in all patients at Stages 1 and 2 were alleviated or disappeared, and the cranial bones developed without deformity during follow-up. Among patients with Stage 3 GSF, no obvious improvement in neurological deficits was observed. Three patients underwent additional operations because of cranial deformation or infection. The authors identify the stages of GSF according to a new hypothesis. They conclude that accurately diagnosing and treating GSF during Stages 1 and 2 leads to a better prognosis.

  10. [Lung cancer and COPD - growing clinical problem].

    Science.gov (United States)

    Tyl, Michal; Domagała-Kulawik, Joanna

    2017-07-21

    A spread of the addiction of tobacco smoking is valued on near 1 billion of people in the world, that involves growing number of morbidity and mortality by the reason of smoke related diseases. Lung cancer and chronic obstructive pulmonary disease (COPD) are the most serious and incurable diseases which are leading to a permanent disability as well as to premature death. There are factors that naturally increase the vulnerability of an individual on the coincidence of above disorders, such as pathophysiological conditions, systemic inflammation, bronchitis, emphysema, respiratory obstructive disease and precise genetic predispositions for COPD and lung cancer. The harmful substances of the tobacco smoke are the causes of the development of diseases outside the group of respiratory disorders which affects the greater scope of comorbidity among this patient group in comparison to the normal population. The similarity of the clinical picture of lung cancer and COPD may cause numerous problems for a proper and prompt diagnosis and the implementation of the appropriate treatment. On the other hand, it is evident that the patients with COPD are carefully examined and often diagnosed with cancer while those who already suffer from cancer and undertake additional function testing are in 40-50% diagnosed with COPD. The coexistance of these two diseases influences the therapeutic procedure: COPD limits the possibilities of a radical lung cancer treatment which is determined by the general health condition and the respiratory system insufficiency as far as COPD patients are concerned. The knowledge of common pathogenesis both of cancer and COPD and the mutual relations between them shall positively affect the diagnostic and therapeutic process in the high-risk patient groups.

  11. [Studies on the alkaloids of Senecio scandens growing in Guangdong].

    Science.gov (United States)

    Guo, Xiao-Fang; Liu, Meng-Hua; Peng, Wei; Wang, Yong-Gang; Yang, Cui-Ping; Su, Wei-Wei

    2011-05-01

    To study alkaloids of Senecio scandens growing in Guangdong. The rapid resolution liquid chromatography-electrospray ionization mass spectrometry (RRLC-ESI-MS/MS) was used to analyse alkaloids of Senecio scandens growing in Guangdong, and senkirkine was isolated and purified by silica gel column chromatography. Four alkaloids were identified as senkirkine, dehydrosenkirkine, monocrotaline and adonifoline, and senkirkine was firstly isolated from Senecio scandens growing in Guangdong. Senkirkine is the main component of Senecio scandens growing in Guangdong.

  12. A growing danger: the risks posed by marihuana grow-ops

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, F. [Canadian Electricity Association (Canada)

    2005-02-01

    The proliferation of sophisticated illegal indoor multi-plant marihuana cultivation operations is discussed, focusing primarily on public health and safety issues. Public health issues arise from the high level of molds and pollens caused by high humidity, which can cause asthma, respiratory conditions and allergies, particularly among children, and the likelihood of deadly levels of carbon monoxide build-up resulting from faulty rerouting of the residence's ventilation system. Safety issues discussed are: fires and electrocutions associated with the use of electrical diversions or bipasses to circumvent utility meters, the chemical and electrical hazards involved in investigating and dismantling growing operations, the significant dangers to utility crews who must repair illegal electrical bypasses, injuries by the booby-traps planted to protect the operation from other criminals or law enforcement agents, and the physical danger from the violence, including homicide and assaults, carried out by operators to exert control over production and distribution. Although in general, there is a relaxed attitude towards marihuana use in Canada. there is growing evidence of increasing public concern over large-scale growing operations. Nevertheless, to date operators of grow-ops have been dealt with lightly by the justice system. For example, in British Columbia 11,733 cases have come to the attention of police during the 1997 to 2000 period. Of these about half were dealt with informally (i.e. 'no case' seizures) and 2,255 cases led to at least one offender being convicted. The majority of convictions did not result in custodial dispositions. Only 18 per cent of the cases resulted in prison sentences, the average term being only 4.5 months.

  13. Lighting during grow-out and Salmonella in broiler flocks

    Science.gov (United States)

    Lighting is used during broiler grow-out to modify bird behavior to reach the goals of production. The protocols for lighting intensity vary. In a field project, we evaluated if the lighting protocol impacts the burden of Salmonella in grow-out broiler flocks. Conventional grow-out flocks reared ...

  14. WSGB: A Web Service-Based Growing Book

    Science.gov (United States)

    Dow, C. R.; Huang, L. H.; Chen, K. H.; Chiu, J. C.; Lin, C. M.

    2006-01-01

    Growing Book refers to an electronic textbook that is co-developed, and has the ability to be constantly maintained, by groups of independent authors, thus creating a rich and ever-growing learning environment that can be conveniently accessible from anywhere. This work designs and implements a Web Service-based Growing Book that has the merits of…

  15. On carbon footprints and growing energy use

    Energy Technology Data Exchange (ETDEWEB)

    Oldenburg, C.M.

    2011-06-01

    Could fractional reductions in the carbon footprint of a growing organization lead to a corresponding real reduction in atmospheric CO{sub 2} emissions in the next ten years? Curtis M. Oldenburg, head of the Geologic Carbon Sequestration Program of LBNL’s Earth Sciences Division, considers his own organization's carbon footprint and answers this critical question? In addressing the problem of energy-related greenhouse gas (GHG) emissions and climate change, it is essential that we understand which activities are producing GHGs and the scale of emission for each activity, so that reduction efforts can be efficiently targeted. The GHG emissions to the atmosphere of an individual or group are referred to as the ‘carbon footprint’. This terminology is entirely appropriate, because 85% of the global marketed energy supply comes from carbon-rich fossil fuel sources whose combustion produces CO{sub 2}, the main GHG causing global climate change. Furthermore, the direct relation between CO2 emissions and fossil fuels as they are used today makes energy consumption a useful proxy for carbon footprint. It would seem to be a simple matter to reduce energy consumption across the board, both individually and collectively, to help reduce our carbon footprints and therefore solve the energyclimate crisis. But just how much can we reduce carbon footprints when broader forces, such as growth in energy use, cause the total footprint to simultaneously expand? In this feature, I present a calculation of the carbon footprint of the Earth Sciences Division (ESD), the division in which I work at Lawrence Berkeley National Laboratory (LBNL), and discuss the potential for reducing this carbon footprint. It will be apparent that in terms of potential future carbon footprint reductions under projections of expected growth, ESD may be thought of as a microcosm of the situation of the world as a whole, in which alternatives to the business-as-usual use of fossil fuels are needed if

  16. Leadership Makes a Difference Growing Federal Civilian Leaders

    Science.gov (United States)

    2008-02-22

    St ra te gy R es ea rc h Pr oj ec t LEADERSHIP MAKES A DIFFERENCE : GROWING FEDERAL CIVILIAN LEADERS BY MS. ALICE MUELLERWEISS...to 00-00-2008 4. TITLE AND SUBTITLE Leadership Makes a Difference Growing Federal Civilian Leaders 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c...Education Accreditation. USAWC STRATEGY RESEARCH PROJECT LEADERSHIP MAKES A DIFFERENCE : GROWING FEDERAL CIVILIAN LEADERS by

  17. Olive-Growing in Italy: Economic and Multifunctional Aspects

    OpenAIRE

    Maurizio Lanfranchi; Carlo Giannetto

    2012-01-01

    Olive-growing in Italy represents a particularly qualified and appreciated field in food-processing productions. The relevant interrelations with the history, landscape, environment and culture of our country make olive-growing particularly important not only for the economy of rural areas but also for the positive effects on landscape and surrounding environment. In fact olive-growing is defining itself more and more as a multifunctional enterprise. The presence of olive growers is also emph...

  18. Multifork chromosome replication in slow-growing bacteria

    National Research Council Canada - National Science Library

    Damian Trojanowski; Joanna Holówka; Katarzyna Ginda; Dagmara Jakimowicz; Jolanta Zakrzewska-czerwinska

    2017-01-01

    .... Thus, newborn cells inherit partially duplicated chromosomes. This phenomenon, which is termed multifork replication, occurs among fast-growing bacteria such as Escherichia coli and Bacillus subtilis...

  19. Effects of Temperature and Growing Seasons on Crop Water ...

    African Journals Online (AJOL)

    PROF HORSFALL

    ABSTRACT: Water savings can be improved through reducing agricultural water consumption. The crop water requirement (CWR) depends on several factors including temperature and growing seasons. This study investigated the effects of temperature and growing seasons on CWR in Saudi Arabia. Increase in ...

  20. The effect of lumbosacral manipulation on growing pains

    Directory of Open Access Journals (Sweden)

    Dawid de Beer

    2015-06-01

    Conclusion: The results from this study, specifically the feedback from parent(s/guardians(s and the pain diaries, indicated that spinal manipulation is beneficial in the treatment of growing pains. The results also showed that other methods of treating growing pains, such as simple leg rubs, may also bring relief.

  1. The suitability evaluation of lignocellulosic substrate as growing ...

    African Journals Online (AJOL)

    SAM

    2014-04-02

    Apr 2, 2014 ... The use of peat moss (PM) as a growing media is decreasing due to high costs and environmental considerations. ... hinoki wood sawdust and rice hull) in order to evaluate their use as components of growing media. Lignocellulosic ... polyortanphome, zeolite, coco peat and sawdust are used as growth ...

  2. Using water wisely to feed growing cities | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Tunisia is helping to feed its growing cities by developing more efficient and sustainable agriculture that uses rainwater and recycled urban wastewater. The article Optimising Use of Water for Urban Agriculture: Responding to the challenge of growing water scarcity in Tunisia by Boubaker Houman and Bouraoui Moez, ...

  3. Evolution of Communicative Competence in Adolescents Growing up in Orphanages

    Science.gov (United States)

    Ribakova, Laysan A.; Parfilova, Gulfia G.; Karimova, Lilya Sh.; Karimova, Raushan B.

    2015-01-01

    The article describes features of the communicative competence evolution in adolescents growing up in orphanages. The specificity is revealed and definition is given to key concept of the research, namely "communicative competence". Authors emphasize and demonstrate the evaluation peculiarities of the adolescents, growing up in…

  4. Responses of Calathea species in different growing media ...

    African Journals Online (AJOL)

    NIHORT), Ibadan to investigate the most suitable medium for the growing of Calathea species. Four Calathea species namely: C. ornata; C.nigerica; C. princeps and C.zebrina, were planted each in three growing media made up of top soil; top ...

  5. The growth performance of growing pigs during feed restriction and ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-01-19

    Jan 19, 2009 ... The growth performance of growing pigs during feed ... alimentation study to evaluate the effect of restricting growing pigs at 90, 80 and 70% of the ad libitum ... Data on the body length (BL) and height at shoulders (HS) followed the same trend as observed for ADG. Feed intakes of pigs were significantly ...

  6. Growing media alternatives for forest and native plant nurseries

    Science.gov (United States)

    Thomas D. Landis; Nancy Morgan

    2009-01-01

    The choice of growing medium, along with container type, is one of the critical decisions that must be made when starting a nursery. The first growing medium was called "compost" and was developed in the 1930s at the John Innes Horticultural Institute in Great Britain. It consisted of a loam soil that was amended with peat moss, sand, and fertilizers (Bunt...

  7. Effects of Charcoal Inclusion on the Performance of Growing Rabbits ...

    African Journals Online (AJOL)

    An experiment was carried out to study the effects of charcoal inclusion in the diet of growing rabbits fed Acacia pod meal (APM) diet. Eighteen (18) growing rabbits of mixed breeds (give the crosses) and sexes with an average initial weight of 5202±0.25g were used for this study in a completely randomized design, ...

  8. Growth and Economic Opportunities for Women (GrOW) Frequently ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Alejandra

    Access to journals, academic library, internet and reference management software. • Access to statistical software packages for meta-analysis or software packages for qualitative data analysis are an advantage. Does GrOW promote certain review methods and approaches? GrOW will take a broad perspective on the types ...

  9. Performance and carcass characteristics of growing rabbits fed ...

    African Journals Online (AJOL)

    In an 84 days feeding trial, the effect of feeding bacterial protein meal (BPM) either as a replacement for fish meal or for groundnut cake meal in growing rabbits was examined. A total of 20 growing rabbits having an initial body weight of 617.2 (standard error 25) g were randomly assigned to five dietary treatments. A control ...

  10. Engineering a wild fast-growing Mycoplasma bacterium to generate ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2018-01-12

    Jan 12, 2018 ... To develop a fast growing CCPP vaccine for cheaper production and long term protection, cutting edge synthetic biotechnology tools will be used to delete harmful and nonessential genes from a fast growing bacterium isolated from wild goats. These genes will be replaced by CCPP protective vaccine ...

  11. Assessment of the Growing Season over the Unimodal Rainfall ...

    African Journals Online (AJOL)

    Most part of Tanzania experiences unimodal rainfall. The characteristics of rainfall such as its onset and cessation dates, dry and wet spell lengths, frequency and number of rainy days can be, used to determine the nature of growing season length of growing season end of season and its geographical variation both ...

  12. Assessment of the Growing Season Regime Region of Tanzania ...

    African Journals Online (AJOL)

    cessation dates, dry and wet spell lengths, frequency and number of rainy days can be, used to determine the nature of growing season; length of ... Key words: Agrometeorology, dry spells: growing season, Tanzania, unimodal rainfall. Introduction ..... most statistical' text books and in Okoola and. Salano (2002). Positive ...

  13. Profitability of Eucalyptus growing in Busiro, Mpigi District, Uganda ...

    African Journals Online (AJOL)

    The worthiness of investments in eucalyptus growing has been determined using the net present value (NPV) criterion. It has been proved that investments in eucalyptus growing in perpetuity (forever) and being harvested on a four (4) year rotation period can earn a present value of a perpetual periodic annuity of Ug. shs ...

  14. Molecular Regulation of Photosynthetic Carbon Dioxide Fixation in Nonsulfur Purple Bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Tabita, Fred Robert [The Ohio State Univ., Columbus, OH (United States)

    2015-12-01

    The overall objective of this project is to determine the mechanism by which a transcriptional activator protein affects CO2 fixation (cbb) gene expression in nonsulfur purple photosynthetic bacteria, with special emphasis to Rhodobacter sphaeroides and with comparison to Rhodopseudomonas palustris. These studies culminated in several publications which indicated that additional regulators interact with the master regulator CbbR in both R. sphaeroides and R. palustris. In addition, the interactive control of the carbon and nitrogen assimilatory pathways was studied and unique regulatory signals were discovered.

  15. Growing wealth and growing pains: child and adolescent psychiatry in Hong Kong, Malaysia and Singapore.

    Science.gov (United States)

    Tan, Susan; Fung, Daniel; Hung, Se-Fong; Rey, Joseph

    2008-06-01

    Several Asian regions have undergone a dramatic transformation, some becoming very affluent. This paper aims to ascertain how countries that are becoming wealthy have dealt with child and adolescent mental health issues. Population health status, child and adolescent mental health services, child psychiatry training, the number of child psychiatrists and related matters were examined in Hong Kong, Malaysia and Singapore. Hong Kong, Malaysia and Singapore are ethnically, religiously, socially and politically very different. In spite of considerable wealth and a growing recognition that mental health problems in the young are increasing, they face similar problems--lack of access to treatment due to a dearth of services and a lack of child psychiatrists (2.5, 0.5 and 2.8 per million people, respectively). Because the number of child psychiatrists is so small, their ability to provide services, advocate, train, maintain a professional identity, and deal with future crises is very limited. Other rapidly developing countries can learn from this experience and should take action early to prevent a similar outcome.

  16. Morphoelastic rods. Part I: A single growing elastic rod

    KAUST Repository

    Moulton, D.E.

    2013-02-01

    A theory for the dynamics and statics of growing elastic rods is presented. First, a single growing rod is considered and the formalism of three-dimensional multiplicative decomposition of morphoelasticity is used to describe the bulk growth of Kirchhoff elastic rods. Possible constitutive laws for growth are discussed and analysed. Second, a rod constrained or glued to a rigid substrate is considered, with the mismatch between the attachment site and the growing rod inducing stress. This stress can eventually lead to instability, bifurcation, and buckling. © 2012 Elsevier Ltd. All rights reserved.

  17. Accumulated Growing Degree Days, Contiguous United States, 1981 - Current Year

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The USA National Phenology Network has available a series of gridded products enabling researchers to analyze current year Accumulated Growing Degree Days (AGDD)...

  18. Leadership Makes a Difference Growing Federal Civilian Leaders

    National Research Council Canada - National Science Library

    Muellerweiss, Alice

    2008-01-01

    .... Research indicates that currently our government does not grow effective leaders. Often those "rising to the top" are technical experts with minimal leadership experiences, mostly unacquainted with the fundamentals of leadership...

  19. 7 CFR 319.37-8 - Growing media.

    Science.gov (United States)

    2010-01-01

    ...) Approved growing media are baked expanded clay pellets, coal cinder, coir, cork, glass wool, organic and... starch, polystyrene, polyurethane, rock wool, sphagnum moss, ureaformaldehyde, stockosorb superabsorbent..., i.e., plastic particles, glass wool, organic and inorganic fibers, polyurethane, polystyrene...

  20. Growing grass for a green biorefinery - an option for Ireland?

    NARCIS (Netherlands)

    O'Keeffe, S.; Schulte, R.P.O.; O'Kiely, P.; O'Donoghue, C.; Lalor, S.T.J.; Struik, P.C.

    2010-01-01

    Growing grass for a green biorefinery – an option for Ireland? Mind the gap: deciphering the gap between good intentions and healthy eating behaviour Halting biodiversity loss by 2020 – implications for agriculture A milk processing sector model for Ireland

  1. As World's Population Ages, Blindness Rates Likely to Grow

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_167592.html As World's Population Ages, Blindness Rates Likely to Grow Study ... researchers estimate that 0.75 percent of the world's population was blind in 1990, compared to 0. ...

  2. Lilienfeld Prize Talk: How do massive black holes grow?

    Science.gov (United States)

    Rees, Martin

    2017-01-01

    The supermassive black holes in galactic nuclei evolve in symbiosis with their hosts. This paper will review how they grow, with particular emphasis on mergers, and on the complex phenomena associated with the tidal capture and disruption of stars.

  3. Water quality assessment of razorback sucker grow-out ponds

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Water quality parameters had never been assessed in these grow-out ponds. Historically growth, condition, and survival of razorback suckers have been variable...

  4. Performance and carcass characteristics of growing rabbits fed ...

    African Journals Online (AJOL)

    The inclusion of BPM in diet V reduced the skin weight significantly (p0.05) affected. It was concluded that BPM can completely (to 100 %) replace FM and GNC in the diet of growing rabbits. BPM also ...

  5. Climate Prediction Center Weekly Corn Growing Degree Days

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A corn growing degree day (GDD) is an index used to express crop maturity. The index is computed by subtracting a base temperature of 50?F from the average of the...

  6. Overcrowding of accident & emergency units: is it a growing concern ...

    African Journals Online (AJOL)

    growing among the public and health care professionals. The data supporting ... overcrowding. Keywords: Overcrowding, accident, emergency surgery, Nigeria ... carried out among employees of AEDs in three ma- jor, referral teaching ...

  7. Analysis of multiple genetic polymorphisms in aggressive-growing and slow-growing abdominal aortic aneurysms.

    Science.gov (United States)

    Duellman, Tyler; Warren, Christopher L; Matsumura, Jon; Yang, Jay

    2014-09-01

    The natural history of abdominal aortic aneurysms (AAAs) suggests that some remain slow in growth rate whereas many develop a more accelerated growth rate and reach a threshold for intervention. We hypothesized that different mechanisms are responsible for AAAs that remain slow growing and never become actionable vs the aggressive AAAs that require intervention and may be reflected by distinct associations with genetic polymorphisms. AAA growth rate was determined from serial imaging data in 168 control and 141 AAA patients with ultrasound or computed tomography imaging studies covering ∼5 years. Genetic polymorphisms all previously reported as showing a significant correlation with AAA with functional effects on the expression or function were determined by analysis of the genomic DNA, including angiotensin 1 receptor (rs5186), interleukin-10 (IL-10; rs1800896), methyl-tetrahydrofolate reductase (rs1801133), low-density lipoprotein receptor-related protein 1 (LRP1; rs1466535), angiotensin-converting enzyme (rs1799752), and several matrix metalloproteinase 9 (MMP-9) single nucleotide polymorphisms. Of the AAA patients, 81 were classified as slow AAA growth rate (3.25 mm/y, those presenting with a rupture, or those with maximal aortic diameter >5.5 cm [male] or >5.0 cm [female]). Discriminating confounds between the groups were identified by logistic regression. Analyses identified MMP-9 p-2502 single nucleotide polymorphism (odds ratio [OR], 0.54; 95% confidence interval [CI], 0.31-0.94; P = .029) as a significant confound discriminating between control vs slow-growth AAA, MMP-9 D165N (OR, 0.49; 95% CI, 0.26-0.95; P = .035) and LRP1 (OR, 4.99; 95% CI, 1.13-22.1; P = .034) between control vs aggressive-growth AAAs, and methyltetrahydrofolate reductase (OR, 2.99; 95% CI, 1.01-8.86; P = .048), MMP-9 p-2502 (OR, 2.19; 95% CI, 1.05-4.58; P = .037), and LRP1 (OR, 4.96; 95% CI, 1.03-23.9; P = .046) as the statistically significant confounds distinguishing slow

  8. Colonisation of soilless growing media for tomato by Trichoderma harzianum.

    Science.gov (United States)

    De Schutter, B; Aerts, R; Rombouts, L

    2001-01-01

    An experiment was conducted to evaluate the distribution of T. harzianum in soilless media used in greenhouse growing systems for tomatoes. Growing media based on rockwool and based on coconut fibre were included. The fungus was applied to the roots of the plant by means of a conidial suspension. The upper plant parts were removed from the coconut fibre an the rockwool slab after 10 and 15 weeks respectively. Both the coconut fibre and the rockwool slab were divided into fragments with a width of 10 cm. The coconut fibre medium fragments were again divided in an upper and a lower part. For every fragment the CFU/g was determined by two different methods. In the first method a known volume of growing medium was brought into suspension using a blender and diluted. Appropriate dilutions were plated on a selective medium. In the second method a known volume of growing medium was spread directly upon a selective medium in petri dishes. All dishes were incubated at room temperature and colonies were counted. Results showed that in the case of the coconut fibre growing medium T. harzianum was isolated in every fragment of the substrate. Highest densities were measured at the site of inoculation. In the lower part of the fragments less CFU/g were counted than in the upper part. In the case of the rockwool growing medium, there were several fragments in which no T. harzianum was isolated. The dilution technique demonstrated to be most useful in cases of high density. The direct spreading-method is best applied when low densities are expected. These observations demonstrate that the growing medium based upon coconut fibre is more appropriate for colonisation by T. harzianum. However, densities are higher at the site of inoculation in both tested growing media.

  9. Effects of temperature and growing seasons on crop water ...

    African Journals Online (AJOL)

    The crop water requirement (CWR) depends on several factors including temperature and growing seasons. This study investigated the effects of temperature and growing seasons on CWR in Saudi Arabia. Increase in temperature by 1°C increased the CWR by 1.9 - 2.9%, 1.9 – 3.0% and 2.2 – 3.8% for dates, alfalfa and ...

  10. Blueprint and Approach to Grow Revenue in Small Technology Companies

    OpenAIRE

    Tony Bailetti

    2010-01-01

    This article examines a new approach to grow the revenue of small technology companies and technology startups. We name this new approach the business ecosystem approach. The article is organized into five sections. The first section provides a blueprint to grow revenue and an inventory of growth formulas that top management teams of small technology companies and founders of startups find useful. The second section briefly defines business ecosystems, keystones and platforms. The third secti...

  11. Understanding Economic Growth: Review Article of Why Economies Grow

    OpenAIRE

    Andrew Sharpe

    2004-01-01

    The question of why economies grow has been at the heart of economic inquiry since Adam Smith. The final article is a review of the recent book Why Economies Grow: The Forces That Shape Prosperity and How to Get Them Working Again by Jeff Madrick. He argues that the growth of markets through trade, colonization, and domestic expansion was the predominate factor in Western economic development. While technological innovation is necessary to growth, it is as much a consequence of economic oppor...

  12. Blueprint and Approach to Grow Revenue in Small Technology Companies

    Directory of Open Access Journals (Sweden)

    Tony Bailetti

    2010-05-01

    Full Text Available This article examines a new approach to grow the revenue of small technology companies and technology startups. We name this new approach the business ecosystem approach. The article is organized into five sections. The first section provides a blueprint to grow revenue and an inventory of growth formulas that top management teams of small technology companies and founders of startups find useful. The second section briefly defines business ecosystems, keystones and platforms. The third section describes the business ecosystem approach to grow the revenue of small technology companies and technology startups. It compares the traditional and business ecosystem approaches to growing revenue; identifies when the business ecosystem approach works better than the traditional approach; explains what small companies and startups need to do to grow revenue using the business ecosystem approach; and describes the benefits and risks of implementing the business ecosystem approach. The fourth section compares three approaches to growing revenue and highlights the differences between i business ecosystems and development communities and ii the business ecosystem approach and outsourcing. The fifth section identifies the key decisions a small technology company or technology startup needs to make to become the keystone that anchors a business ecosystem.

  13. The formation and growing properties of poly(ethylene terephthalate) fiber growing media after thermo-oxidative treatment

    Energy Technology Data Exchange (ETDEWEB)

    Chang, C.P. [Department of Textile Engineering, Chinese Culture University, Taipei 11192, Taiwan (China)], E-mail: cpchang@staff.pccu.edu.tw; Lin, S.M. [Department of Materials and Textiles, Oriental Institute of Technology, Pan-Chiao 220, Taiwan (China)

    2007-05-25

    This research uses three kinds of recycled synthetic fibers that all possess excellent thermal plasticity property as raw material to develop a new firm cultivation media: polyethylene terephthalate, polyamide and polypropylene. One can not only freely control plants cultivation growing condition by changing bulk density of the media, but also solve disposal problem after usage by applying thermal oxidative treatment during manufacturing processes. The water content, air permeability and formation conditions of these fiber growing media that are required in plants growing habitat were discussed, and compared the fallout with rockwool (RW) growing media that is commonly used at present days. The results indicated that the polyethylene terephthalate fiber media could attain best formation characteristics among these fibers at the same bulk density range. Furthermore, the fiber media that were thermo-oxidative treated at 240-260 deg. C could obtained above 90% total porosity, 23-49% air capacity and 48-68% water availability, water contents raised from 1735-1094 to 2145-1156% under bulk densities of 0.03-0.09 g/cm{sup 3}, which conforms to the common plant growing habitat conditions. Its performance well surpasses the rockwool growing media. We also discovered that the thermo-oxidative treated polyethylene terephthalate (PET) fiber media could be easily broken down and become powdery by exerting pressure, thus greatly reduce its volume and effectively improve disposal processes that are difficult presently for the huge refuse create by rockwool.

  14. The effect of lumbosacral manipulation on growing pains

    Directory of Open Access Journals (Sweden)

    Dawid de Beer

    2015-10-01

    Objective: The aim of this study was to determine whether lumbosacral manipulations have an effect on growing pain symptoms. Methods: Thirty participants with growing pains between the ages of 4 and 12 years were recruited. The participants were placed into two groups of 15 participants each. Group 1 received lumbosacral manipulations to restricted joints as determined by motion palpation, while Group 2 never received any professional intervention. Often parent(s/guardian(s of children who suffer from growing pains will rub the child's legs and offer verbal reassurance in an attempt to console their children. Parent(s/guardian(s of both groups were encouraged to continue to do this throughout the duration of the trial. Instructions were given to the parents so that the same rubbing technique and rubbing cream (aqueous cream were used. Subjective changes were tracked using a pain diary that the parent(s/guardian(s were asked to complete, a six-week post-study follow-up question regarding children's growing pains and the Oucher self-report pain scale. Objective measures consisted of pressure algometer readings of the tibialis anterior muscle belly. Results: The statistical data was analysed using the Friedman test, Manne—Whitney test and the Wilcoxon Signed-Rank test. The results demonstrated that both groups responded favourably to their specific treatment over time. However, the group that received lumbosacral manipulations proved to show a quicker response to treatment; and the post study follow-up of this same group showed markedly more positive feedback than the group that did not receive the treatment. These results highlighted the positive effects of chiropractic manipulation on growing pain symptoms. Conclusion: The results from this study, specifically the feedback from parent(s/guardians(s and the pain diaries, indicated that spinal manipulation is beneficial in the treatment of growing pains. The results also showed that other methods of treating growing

  15. Lighting during grow-out and Salmonella in broiler flocks

    Directory of Open Access Journals (Sweden)

    Bailey Richard H

    2010-06-01

    Full Text Available Abstract Background Lighting is used during conventional broiler grow-out to modify bird behaviour to reach the goals of production and improve bird welfare. The protocols for lighting intensity vary. In a field study, we evaluated if the lighting practices impact the burden of Salmonella in broiler flocks. Methods Conventional grow-out flocks reared in the states of Alabama, Mississippi and Texas, USA in 2003 to 2006 were sampled 1 week before harvest (n = 58 and upon arrival for processing (n = 56 by collecting feathered carcass rinsate, crop and one cecum from each of 30 birds, and during processing by collecting rinsate of 30 carcasses at pre-chilling (n = 56 and post-chilling points (n = 54. Litter samples and drag swabs of litter were collected from the grow-out houses after bird harvest (n = 56. Lighting practices for these flocks were obtained with a questionnaire completed by the growers. Associations between the lighting practices and the burden of Salmonella in the flocks were tested while accounting for variation between the grow-out farms, their production complexes and companies. Results Longer relative duration of reduced lights during the grow-out period was associated with reduced detection of Salmonella on the exterior of birds 1 week before harvest and on the broiler carcasses at the post-chilling point of processing. In addition, starting reduced lights for ≥18 hours per day later in the grow-out period was associated with decreased detection of Salmonella on the exterior of broilers arriving for processing and in the post-harvest drag swabs of litter from the grow-out house. Conclusions The results of this field study show that lighting practices implemented during broiler rearing can impact the burden of Salmonella in the flock. The underlying mechanisms are likely to be interactive.

  16. Measuring efficiency of rice growing farmers using data envelopment analysis

    Science.gov (United States)

    Zaibidi, Nerda Zura; Kasim, Maznah Mat; Ramli, Razamin; Baten, Md. Azizul; Khan, Sahubar Ali Nadhar

    2015-12-01

    Self-sufficiency in rice production has been the main issue in Malaysia agriculture. It is significantly low and does not comply with the current average rice yield of 3.7 tons per ha per season. One of the best options and the most effective way to improve rice productivity is through more efficient utilization of paddy farmers. Getting farmers to grow rice is indeed a challenge when they could very well be making better money doing something else. This paper attempts to study the efficiency of rice growing farmers in Kubang Pasu using Data Envelopment Analysis model. For comparative analysis, three scenarios are considered in this study in measuring efficiency of rice growing farmers. The first scenario considers only fertilizer factor as an input while for the second, the land size is added as another factor. The third scenario considers more details about the inputs such as the type of fertilizer, NPK and mixed and also land tenureship and size. In all scenarios, the outputs are rice yield (tons) and the profit (RM). As expected, the findings show that the third scenario establishes the highest number of efficient rice growing farmers. It reveals that the combination of outputs and inputs chosen has significant contribution in measuring efficiency of rice growing farmers.

  17. Morphodynamics of a growing microbial colony driven by cell death

    Science.gov (United States)

    Ghosh, Pushpita; Levine, Herbert

    2017-11-01

    Bacterial cells can often self-organize into multicellular structures with complex spatiotemporal morphology. In this work, we study the spatiotemporal dynamics of a growing microbial colony in the presence of cell death. We present an individual-based model of nonmotile bacterial cells which grow and proliferate by consuming diffusing nutrients on a semisolid two-dimensional surface. The colony spreads by growth forces and sliding motility of cells and undergoes cell death followed by subsequent disintegration of the dead cells in the medium. We model cell death by considering two possible situations: In one of the cases, cell death occurs in response to the limitation of local nutrients, while the other case corresponds to an active death process, known as apoptotic or programmed cell death. We demonstrate how the colony morphology is influenced by the presence of cell death. Our results show that cell death facilitates transitions from roughly circular to highly branched structures at the periphery of an expanding colony. Interestingly, our results also reveal that for the colonies which are growing in higher initial nutrient concentrations, cell death occurs much earlier compared to the colonies which are growing in lower initial nutrient concentrations. This work provides new insights into the branched patterning of growing bacterial colonies as a consequence of complex interplay among the biochemical and mechanical effects.

  18. Growing Up of Autonomous Agents: an Emergent Phenomenon

    Science.gov (United States)

    Morgavi, Giovanna; Marconi, Lucia

    2008-10-01

    A fundamental research challenge is the design of robust artifacts that are capable of operating under changing environments and noisy input, and yet exhibit the desired behavior and response time. These systems should be able to adapt and learn how to react to unforeseen scenarios as well as to display properties comparable to biological entities. The turn to nature has brought us many unforeseen great concepts. Biological systems are able to handle many of these challenges with an elegance and efficiency still far beyond current human artifacts. A living artifact grows up when its capabilities, abilities/knowledge, shift to a further level of complexity, i.e. the complexity rank of its internal capabilities performs a step forward. In the attempt to define an architecture for autonomous growing up agents [1]. We conducted an experiment on the abstraction process in children as natural parts of a cognitive system. We found that linguistic growing up involve a number of different trial processes. We identified a fixed number of distinct paths that were crossed by children. Once a given interpretation paths was discovered useless, they tried to follow another path, until the new meaning was emerging. This study generates suggestion about the evolutionary conditions conducive to the emergence of growing up in robots and provides guidelines for designing artificial evolutionary systems displaying spontaneous adaptation abilities. The importance of multi-sensor perception, motivation and emotional drives are underlined and, above all, the growing up insights shows similarities to emergent self-organized behaviors.

  19. Marijuana growing operations in British Columbia revisited, 1997-2003

    Energy Technology Data Exchange (ETDEWEB)

    Plecas, D.; Malm, A.; Kinney, B. [University College of the Fraser Valley, Abbotsford, BC (Canada). Dept. of Criminology and Criminal Justice]|[University College of the Fraser Valley, Abbotsford, BC (Canada). International Centre for Urban Research Studies

    2005-03-01

    The results of a comprehensive study of marihuana cultivation in British Columbia were presented. This report describes the incidents of marihuana grow operations coming to the attention of the police; the characteristics of marihuana growing operations; the suspects involved; the actions taken by the police and courts; and penalty. The study confirms that these operations which are dispersed throughout the province are increasing in both size and sophistication. The average number of kilograms of harvested marihuana seized per grow operation tripled from 1997 to 2003. In addition, the number of high intensity lights seized per operation also grew, leading to an associated increase in the average amount of electricity theft per operation. About 1 in 5 grow operations involved hydro theft. The average cost associated with hydro theft per operation was about $2,880 in 1997 and $3,740 in 2003. In 2003, it is estimated that growers stole more than $3,200,000 from BC Hydro. In addition to electricity by-passes, 15 per cent of indoor grow operations contained hazards such as weapons, explosives, and other drugs. 25 tabs., 34 figs.

  20. Adsorption of Heavy Metal Ions to Floc-Type Biosorbents

    OpenAIRE

    Seki, Hideshi; Suzuki, Akira

    2002-01-01

    Adsorption of cadmium and lead ions to floc-type biosorbents was reported in this work. Two types of biosorbents containing a marine microalga, Heterosigma akashiwo (Hada) Hada or a purple non-sulfur bacterium, Rhodobacter sphaeroides were prepared. The microorganisms inactivated by steam sterilization were immobilized in casein floc and cross-linked with glutaraldehyde. In the present immobilizing method, we obtained the biosorbents comprising as much as 67% of microorganism on a dry-weight ...

  1. Electrostatic calculations of amino acid titration and electron transfer, Q-AQB-->QAQ-B, in the reaction center.

    OpenAIRE

    Beroza, P; Fredkin, D R; Okamura, M Y; Feher, G

    1995-01-01

    The titration of amino acids and the energetics of electron transfer from the primary electron acceptor (QA) to the secondary electron acceptor (QB) in the photosynthetic reaction center of Rhodobacter sphaeroides are calculated using a continuum electrostatic model. Strong electrostatic interactions between titrating sites give rise to complex titration curves. Glu L212 is calculated to have an anomalously broad titration curve, which explains the seemingly contradictory experimental results...

  2. Conformational regulation of charge recombination reactions in a photosynthetic bacterial reaction center

    DEFF Research Database (Denmark)

    Katona, Gergely; Snijder, Arjan; Gourdon, Pontus

    2005-01-01

    In bright light the photosynthetic reaction center (RC) of Rhodobacter sphaeroides stabilizes the P(+)(870).Q(-)(A) charge-separated state and thereby minimizes the potentially harmful effects of light saturation. Using X-ray diffraction we report a conformational change that occurs within the cy...... the cytoplasmic domain of this RC in response to prolonged illumination with bright light. Our observations suggest a novel structural mechanism for the regulation of electron transfer reactions in photosynthesis....

  3. Exploring the Presence of microDNAs in Prostate Cancer Cell Lines, Tissue, and Sera of Prostate Cancer Patients and its Possible Application as Biomarker

    Science.gov (United States)

    2016-04-01

    Saccharomyces cerevisiae [32] and the bacterium Rhodobacter sphaeroides [3]. tRF-5s and tRF-3s are observed in all the species (Figure 2B). However fewer...permits unrestricted reuse, distribution, and reproduction in any medium , provided the original work is properly cited. at U N IV E R SIT Y O F V IR G...Attribution License (http://creativec reproduction in any medium , provided the or Dedication waiver (http://creativecommons.or unless otherwise

  4. Growing older in the context of needing geriatric assessment

    DEFF Research Database (Denmark)

    Esbensen, Bente Appel; Hvitved, Ida; Andersen, Hanne Elkjær

    2016-01-01

    methodology. RESULTS: The results led to an overall essence and five themes. The five themes were identified: (i) considerations to avoid weakness, (ii) compensation for the inability to perform certain activities, (iii) aides - a symbol of freedom or limitation, (iv) lifestyle considered being particularly...... limitations in every daily life had the status of either creating freedom or being limiting in things they wished to do. Considerations about lifestyle were focused on housing and change of dwelling. This also led to thoughts about the future and end of life. Additional research regarding accommodations...... significant and (v) considerations about the end of life as a component of growing older. The essence was defined as: illness essential for the experience of growing older and pointed to the experience of growing older that highlighted that experiencing illnesses and limitations served as reminders...

  5. Meeting growing urban water needs through water reclamation and reuse

    Energy Technology Data Exchange (ETDEWEB)

    Okun, D.A. [Univ. of North Carolina, Chapel Hill, NC (United States)

    1994-12-31

    The subject of this presentation is the crisis in water management that results from exploding urban population growth. The world population is growing at a rate of almost 100 million per year, with urban growth being most of that. The problems of providing water and controlling pollution grow exponentially as population grows. Sources of water need to be larger and are inevitably more distant and more costly, if available. In urban areas, with attendant commercial and industrial enterprises, the concentrated heavy loads of pollutants seriously overburden receiving waters. Fish is often destroyed, with the loss of both essential food and employment, to say nothing of the impact of urban pollution on downstream water supplies.

  6. On the mechanics of thin films and growing surfaces

    KAUST Repository

    Holland, M. A.

    2013-05-24

    Many living structures are coated by thin films, which have distinct mechanical properties from the bulk. In particular, these thin layers may grow faster or slower than the inner core. Differential growth creates a balanced interplay between tension and compression and plays a critical role in enhancing structural rigidity. Typical examples with a compressive outer surface and a tensile inner core are the petioles of celery, caladium, or rhubarb. While plant physiologists have studied the impact of tissue tension on plant rigidity for more than a century, the fundamental theory of growing surfaces remains poorly understood. Here, we establish a theoretical and computational framework for continua with growing surfaces and demonstrate its application to classical phenomena in plant growth. To allow the surface to grow independently of the bulk, we equip it with its own potential energy and its own surface stress. We derive the governing equations for growing surfaces of zero thickness and obtain their spatial discretization using the finite-element method. To illustrate the features of our new surface growth model we simulate the effects of growth-induced longitudinal tissue tension in a stalk of rhubarb. Our results demonstrate that different growth rates create a mechanical environment of axial tissue tension and residual stress, which can be released by peeling off the outer layer. Our novel framework for continua with growing surfaces has immediate biomedical applications beyond these classical model problems in botany: it can be easily extended to model and predict surface growth in asthma, gastritis, obstructive sleep apnoea, brain development, and tumor invasion. Beyond biology and medicine, surface growth models are valuable tools for material scientists when designing functionalized surfaces with distinct user-defined properties. © The Author(s) 2013.

  7. The Fundamental Right To Grow Old With Dignity

    Directory of Open Access Journals (Sweden)

    Camila Rabelo de Matos Silva Arruda

    2016-12-01

    Full Text Available Over the years the role the growing old in society has been changing considerably, the population is aging and increasing life expectancy. Law No. 10741/03, which established the Statute of the Elderly, where the legislator sought to ensure the right to grow old with dignity. The increase in the number of retirees and unemployment generated changing the demand in the social security system, which is being processed at the national congress. This article examines how society has been treating the elderly and preparing to deal with the aging population.

  8. Cyber-physical attacks a growing invisible threat

    CERN Document Server

    Loukas, George

    2015-01-01

    Cyber-Physical Attacks: A Growing Invisible Threat presents the growing list of harmful uses of computers and their ability to disable cameras, turn off a building's lights, make a car veer off the road,  or a drone land in enemy hands. In essence, it details the ways cyber-physical attacks are replacing physical attacks in crime, warfare, and terrorism. The book explores how attacks using computers affect the physical world in ways that were previously only possible through physical means. Perpetrators can now cause damage without the same risk, and without the political, social, or moral

  9. Sports and the Growing Musculoskeletal System: Sports Imaging Series.

    Science.gov (United States)

    Nguyen, Jie C; Sheehan, Scott E; Davis, Kirkland W; Gill, Kara G

    2017-07-01

    Increased youth participation in sports has resulted in increased injury tolls due to shifts toward participation in competitive sports at earlier ages, increased training intensity and competition schedules, as well as specialization into one sport. The physiology of the growing musculoskeletal system makes the growing athlete particularly vulnerable to specific types of injuries. Radiologists must understand the differences between pediatric and adult athletes to recognize the particular injuries to which these young athletes are prone. Imaging and pertinent clinical details of major representative acute and overuse injuries characteristic to pediatric athletes will be discussed. © RSNA, 2017.

  10. Clinical Challenges in the Growing Medical Marijuana Field.

    Science.gov (United States)

    Barker, Jonathan

    2018-02-02

    Unique clinical challenges arise with the growing number of patients who possess medical marijuana cards. Medical marijuana patients with mental disorders can have worsening symptoms with marijuana use. Often there is sparse continuity of care between the patient and the medical marijuana practitioner. Lack of communication between the patient's treating practitioners and the practitioner who has authorized the medical marijuana can be problematic. This article is a discussion of the new clinical challenges practitioners are likely to encounter with the growing number of medical marijuana patients. [Full article available at http://rimed.org/rimedicaljournal-2018-02.asp].

  11. Soybeans Growing inside the Advanced Astroculture Plant Growth Chamber

    Science.gov (United States)

    2003-01-01

    This composite image shows soybean plants growing in the Advanced Astroculture experiment aboard the International Space Station during June 11-July 2, 2002. DuPont is partnering with NASA and the Wisconsin Center for Space Automation and Robotics (WCSAR) at the University of Wisconsin-Madison to grow soybeans aboard the Space Station to find out if they have improved oil, protein, carbohydrates or secondary metabolites that could benefit farmers and consumers. Principal Investigators: Dr. Tom Corbin, Pioneer Hi-Bred International Inc., a Dupont Company, with headquarters in Des Moines, Iowa, and Dr. Weijia Zhou, Wisconsin Center for Space Automation and Robotics (WCSAR), University of Wisconsin-Madison.

  12. Photofermentative production of hydrogen and poly-β-hydroxybutyrate from dark fermentation products.

    Science.gov (United States)

    Luongo, Vincenzo; Ghimire, Anish; Frunzo, Luigi; Fabbricino, Massimiliano; d'Antonio, Giuseppe; Pirozzi, Francesco; Esposito, Giovanni

    2017-03-01

    The aim of this work is to investigate the hydrogen and poly-β-hydroxybutyrate (PHB) production during the photofermentative treatment of the effluent from a dark fermentation reactor fed with the organic fraction of municipal solid waste. Two different inocula, an adapted culture of Rhodobacter sphaeroides AV1b and a mixed consortium of purple non sulphur bacteria have been investigated under the same operational conditions. Different hydrogen productivities of 364 and 559NmL H2 L-1 were observed for the Rhodobacter sphaeroides and the mixed culture consortium tests, respectively: the consortium of PNSB resulted 1.5-fold more productive than the pure culture. On the other hand, Rhodobacter sphaeroides culture showed a higher PHB productivity (155mg PHB g COD-1) than the mixed culture (55mg PHB g COD-1). In all the tests, the concomitant H2 and PHB production was associated to a dissolved COD removal higher than 80%. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Performance of growing rabbits fed graded levels of sugarcane peel ...

    African Journals Online (AJOL)

    Twenty five growing rabbits of mixed breeds and average weight of 894g were used in a seven week feeding trial. Five experimental diets were formulated in which sugarcane peels (SCP) was included at 0, 10, 20, 30 and 40% levels to replace maize offal. The rabbits were balanced for weight and allotted to the treatments ...

  14. Growing pigs fed cassava peel based diet supplemented with or ...

    African Journals Online (AJOL)

    36 growing pigs (average initial weight of 22.74 ± 0.88 kg) were allotted to three dietary treatment groups of 30%maize-based control diet and 30%cassava-peel based diet supplemented with or without Farmazyme® 3000 proenx. Each treatment had three replicates of 4 pigs/replicate (12 pigs/treatment) in a complete ...

  15. America's Growing Dilemma: Pesticides in Food and Water.

    Science.gov (United States)

    Strauss, Valerie; Sullivan, Monica, Ed.

    Public concern about the safety of continued reliance on pesticides in agricultural production is widespread and growing. The lack of understanding of how food is grown, the role of pesticides in food production, the risk assessment and regulatory processes and alternatives to pesticide use limits citizen participation in food safety debates and…

  16. The Influence of seed treatments and growing media on seedling ...

    African Journals Online (AJOL)

    A nursery trial was conducted to investigate the effects of seed treatments and soil type growing media on the germination and growth of Plukenetia conophorum. The factors considered included seed treatments with hot water at 90°C, warm water at 60°C, overnight soaking in cold water and scarification. Soil type media ...

  17. Antileishmanial activity of some plants growing in Algeria: Juglans ...

    African Journals Online (AJOL)

    The current study was undertaken to evaluate in vitro the antileishmanial activity of three plants growing wild in Algeria : Juglans regia, Lawsonia inermis and Salvia officinalis. The hydroalcoholic extracts of these plants were tested on the growth of the promastigotes of Leishmania major. The plant extract effects were ...

  18. Analyses of body weight patterns in growing pigs

    DEFF Research Database (Denmark)

    Stygar, A. H.; Dolecheck, K. A.; Kristensen, A. R.

    2018-01-01

    Frequent BW monitoring of growing pigs can be useful for identifying production (e.g. feeding), health and welfare problems. However, in order to construct a tool which will properly recognize abnormalities in pigs’ growth a precise description of the growth process should be used. In this study ...

  19. Haematological and serum biochemical response of growing rabbit ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-03

    Dec 3, 2008 ... assess haematological and serum biochemical response of growing rabbits exposed to varied levels of dietary ... the diets. Serum total protein, albumin and albumin-globulin ratio significantly (P < 0.05) decreased with increase in the dietary fumonisin levels. Serum total ... Digestible energy (Kcal/Kg). 2555.

  20. Variations and Trends in the Length of the Hydrologic Growing ...

    African Journals Online (AJOL)

    This paper examine the pattern of the Hydrologic Growing Season in a part of North western Nigeria in relation to crop Production and yield. It makes use of daily rainfall data obtained from Sokoto Agricultural Development project data were also obtained from the Nigeria Meteorological services Oshodi (SADP) in two ...

  1. The suitability evaluation of lignocellulosic substrate as growing ...

    African Journals Online (AJOL)

    SAM

    2014-04-02

    Apr 2, 2014 ... Division of Environmental Forest Science and Institute of Agriculture and Life Science, Gyeongsang National University,. Jinju, 660-701 ... as substrate to grow Chinese cabbage (Brassica rapa var. glabra) in a greenhouse. Different ... All over the world, stone wool and other materials like perlite, pumice,.

  2. in_focus - Growing Better Cities: Urban Agriculture for Sustainable ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    The United Nations predicts that over the next 25 years nearly all population growth will be in the cities of the developing world. At current rates, 60% of the world's total population will live in cities by 2030. As the cities grow, so does the number of urban poor. Unemployment, hunger, and malnutrition are commonplace.

  3. Haematological and Biochemical Indices of Growing Lambs Fed ...

    African Journals Online (AJOL)

    acer

    Haematological and Biochemical Indices of Growing Lambs Fed Fore-Stomach Digesta and Poultry Litter Waste. *. 1. A. Aruwayo,. 2. Maigandi, S.A., Malami, B.S., and Daneji, A. I.. 1 National Productivity Centre, P. O. Box, 4243, Sokoto. 2 Department of Animal Science, Faculty of Agriculture, Usmanu Danfodiyo University, ...

  4. Introduction of deciduous fruit tree growing in the tropical highlands ...

    African Journals Online (AJOL)

    Mo

    to develop the deciduous fruit tree growing as a profitable enterprise. Twenty-four out .... altitudes. Significance levels were considered at 95% confidence limits. Results. Fruiting species and Cultivars. Four major deciduous fruit tree species, namely; apples, ... 71.02. 10.00. On-farm performance and management practices.

  5. Growing with EASE: Eating, Activity, and Self-Esteem

    Science.gov (United States)

    Huettig, Carol; Rich, Shannon; Engelbrecht, Jo Ann; Sanborn, Charlotte; Essery, Eve; DiMarco, Nancy; Velez, Luisa; Levy, Luba

    2006-01-01

    A diverse group of professionals associated with Texas Woman's University's Institute for Women's Health, working collaboratively with school administrators, teachers, family support teams, and family members, developed Growing with EASE: Eating, Activity, and Self-Esteem, a nutrition program for young children and their families. In tracking the…

  6. Moderate cholecalciferol supplementation depresses intestinal calcium absorption in growing dogs

    NARCIS (Netherlands)

    Tryfonidou, M.A.; Stevenhagen, J.J.; Bemd, G.J.C.M. van den; Oosterlaken-Dijksterhuis, M.A.; Deluca, H.F.; Mol, J.A.; Brom, W.E. van den; Leeuwen, J.P.T.M. van; Hazewinkel, H.A.W.

    2002-01-01

    Hormonal regulation of calcium (Ca) absorption was investigated in a cholecalciferol (vitamin D3)supplemented group (hVitD) vs. a control group (cVitD) of growing Great Danes (100 vs. 12.5 μg vitamin D3/kg diet). Although Ca intakes did not differ, fractional Ca absorption was significantly lower in

  7. Soil bacteria help Ethiopian farmers grow more nutritious and higher ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2013-01-11

    Jan 11, 2013 ... Pulses — such as chickpeas, lentils, and beans — can fight malnutrition and release the soil's potential for growing high-yield, healthy pulses. ... “Good soil fertility is critical to increasing crop yields, which can make a real difference for food security and the incomes of smallholders, especially women and ...

  8. Performance Of Growing Rabbits Fed Graded Levels Of Goat ...

    African Journals Online (AJOL)

    A ten-week feeding trial was conducted to assess the biological and economic performance of growing rabbits fed graded levels of goat rumen content (GRC). The GRC which contained 27.25% crude protein and 28.33% crude fibre were included at 0, 10, 20, 30, and 40% levels in diets 1, 2, 3, 4 and 5 respectively to ...

  9. Relationships of a growing magnetic flux region to flares

    NARCIS (Netherlands)

    Schadee, A.; Martin, S.F.; Bentley, R.D.; Antalova, A.; Kucera, A.; Dezs, L.; Gesztelyi, L.; Harvey, K.L.; Jones, H.; Livi, S.H.B.; Wang, J.

    1984-01-01

    Some sites for solar flares are known to develop where new magnetic flux emerges and becomes abutted against opposite polarity pre-existing magnetic flux (review by Galzauskas/1/). We have identified and analyzed the evolution of such flare sites at the boundaries of a major new and growing magnetic

  10. The effect of lumbosacral manipulation on growing pains | de Beer ...

    African Journals Online (AJOL)

    Often parent(s)/guardian(s) of children who suffer from growing pains will rub the child's legs and offer verbal reassurance in an attempt to console their children. Parent(s)/guardian(s) of both groups were encouraged to continue to do this throughout the duration of the trial. Instructions were given to the parents so that the ...

  11. Helping Educators Grow: Strategies and Practices for Leadership Development

    Science.gov (United States)

    Drago-Severson, Eleanor

    2012-01-01

    How can we prepare practicing and aspiring education leaders for the complex, adaptive challenges they face? In "Helping Educators Grow," Eleanor Drago-Severson presents a new approach to leadership development. Too often, she argues, we teach leadership development the same way we teach world history: just the facts. Instead, we need to…

  12. Freezing tolerance of wheat cultivars at the early growing season ...

    African Journals Online (AJOL)

    2012-02-28

    Feb 28, 2012 ... Cold stress is a worldwide abiotic stress in temperate regions that affects plant development and yield of winter wheat (Triticum aestivum L.) cultivars and other winter crops. This study was conducted to evaluate the effect of freezing stress at the early growing season on survival and also the relationship.

  13. Growing reforestation conifer stock: Utilizing peat/sawdust medium

    Science.gov (United States)

    Janice K. Schaefer

    2009-01-01

    Western Forest Systems, Incorporated (WFS) (Lewiston, ID) has been utilizing a peat/sawdust blended mix as our growing medium for the past 10 years. Our decision to change from a peat/vermiculite blend to a peat/Douglas-fir (Pseudotsuga menziesii) sawdust blend involved worker health and safety issues, seedling culture, seedling production, and...

  14. Population level response of downy brome to soil growing medium

    Science.gov (United States)

    Downy brome (Bromus tectorum) is the most ubiquitous exotic invasive weed in the Intermountain West. A major issue for management is the extreme generalist plastic nature of downy brome. We hypothesized that soil growing medium would effect all measured response variables representing some degree of...

  15. Freezing tolerance of wheat cultivars at the early growing season ...

    African Journals Online (AJOL)

    Cold stress is a worldwide abiotic stress in temperate regions that affects plant development and yield of winter wheat (Triticum aestivum L.) cultivars and other winter crops. This study was conducted to evaluate the effect of freezing stress at the early growing season on survival and also the relationship between resistances ...

  16. Growing up and being young in an Indonesian provincial town

    NARCIS (Netherlands)

    Minza, W.M.

    2014-01-01

    This study explores the experiences of youth in the provincial town of Pontianak, West Kalimantan, done in Pontianak, the provincial capital of West Kalimantan during the years 2008-2009. It tries to understand the various patterns of relations between growing up and being young, how social

  17. Kinetic measurements on bacterial cultures growing on fibres

    African Journals Online (AJOL)

    rumen bacteria growing on finely dispersed cellulose. Materials and Methods. Organisms. Bacteroides succinogenes S85 and Ruminococcus [lave-. [aciens FD1 were kindly donated by Dr Marvin P. Bryant in about 1960.Ruminococcus albus 22.08.6A and Clostridium polysaccharolyticum B came from the culture collection.

  18. Electronic Waste: A Growing Challenge In Nigeria | Ukem | Global ...

    African Journals Online (AJOL)

    As a consequence, large numbers of electronic ICT products become obsolete each year, and constitute electronic waste. This paper discusses this growing problem of electronic waste from the Nigerian perspective, and highlights factors that can militate against the successful management of such waste in Nigeria.

  19. I don't want to grow old

    DEFF Research Database (Denmark)

    Selberg, Hanne; Sharp-Johansen, Marie-Louise; Evron, Lotte

    the inconveniences of mus-culoskeletal, visual and auditory changes. Five two-hours' workshops were conducted with 60 students in total. The workshops consisted of an initial briefing, scenario performance, debriefing and final evaluation. (Preliminary) Results Themes from analysis: - Concerns of growing old...

  20. Growing Disparities in Life Expectancy. Economic and Budget Issue Brief

    Science.gov (United States)

    Manchester, Joyce; Topoleski, Julie

    2008-01-01

    In a continuation of long-term trends, life expectancy has been steadily increasing in the United States for the past several decades. Accompanying the recent increases, however, is a growing disparity in life expectancy between individuals with high and low income and between those with more and less education. The difference in life expectancy…

  1. Growing small youth businesses in Kenya | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Youth make up a third of Kenya's population. Up to 35% of them are unemployed or work in informal micro-enterprises. Rachel Kalbfleisch, a 2016 IDRC Research Award recipient, wanted to know more about their ambitions and whether these youth planned to grow their businesses.

  2. Play School: Where Children and Families Learn and Grow Together

    Science.gov (United States)

    McDermott, Lori Berger

    2012-01-01

    A growing body of national research confirms that significant levels of learning and growth occur during early childhood, and that it is important, from a public policy perspective, to increase access to quality programs and services that support the development of skills and attitudes children need to succeed. Clearly, no one-size-fits-all…

  3. Growth and haematological response of growing rabbits to diets ...

    African Journals Online (AJOL)

    The growth and haematological response of growing rabbits to diets containing graded levels of Sun dried Bovine Rumen Content (SBRC) was studied for a period of ten weeks. The rumen content was collected from Nsukka abattoirs and dried in sun, ground and stored in sacks. The Composition of SBRC used in this ...

  4. Sugar as an energy source for growing ducklings | Olver | South ...

    African Journals Online (AJOL)

    South African Journal of Animal Science. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 19, No 2 (1989) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Sugar as an energy source for growing ducklings.

  5. NASA's Bioreactor: Growing Cells in a Microgravity Environment. Educational Brief.

    Science.gov (United States)

    National Aeronautics and Space Administration, Washington, DC.

    This brief discusses growing cells in a microgravity environment for grades 9-12. Students are provided with plans for building a classroom bioreactor that can then be used with the included activity on seed growth in a microgravity environment. Additional experimental ideas are also suggested along with a history and background on microgravity…

  6. Growing Sugarcane for Bioenergy – Effects on the Soil

    NARCIS (Netherlands)

    Hartemink, A.E.

    2010-01-01

    An increasing area of sugarcane is being growing for the production of bioenergy. Sugarcane puts a high demands on the soil due to the use of heavy machinery and because large amounts of nutrients are removed with the harvest. Biocides and inorganic fertilizers introduces risks of groundwater

  7. Feed intake, growth performance and nutrient digestibility in growing ...

    African Journals Online (AJOL)

    The study was carried out to evaluate the growth performance, nutrient digestibility and nitrogen intake of growing red sokoto bucks fed graded levels of dried sweet orange (Citrus sinensis) peel meal (DSOPM). Twelve animals aged between 5 – 7 months with average body weight of 9.17 kg were assigned to four dietary ...

  8. Growth response and nutrient digestibility of growing pigs to ...

    African Journals Online (AJOL)

    Growth response and nutrient digestibility of growing pigs to qualitative and quantitative feed restriction. ... Nigerian Journal of Animal Production ... on excreted faeces, faecal dry matter output, excreted faeces/dry matter intake, dry matter digestibility, crude protein digestibility, ether extract, crude fibre digestibility and ash.

  9. Why hardwoods do not grow naturally in the west

    Science.gov (United States)

    J. A. Larsen

    1924-01-01

    Unfortunately the beautiful hardwood trees which are native to the Eastern States do not grow naturally in the West. We have here only aspen, cottonwood, small birch, hawthorns, cherry, and alder. On the Pacific coast are oak and maple, but limited largely to lower moist sites such as streams bed and canyons. The general absence of broad leaf trees in the West is most...

  10. Closed soilless growing systems in the Netherlands: the finishing touch

    NARCIS (Netherlands)

    Os, van E.A.

    1998-01-01

    This paper gives an overview of the latest developments in closed soilless growing systems in the Netherlands, where growers are obliged to invest in environmently friendly cropping systems, in order to comply with new legislation. Subjects of discussion will be the reasons for regulation, the

  11. Eucalypt pests and diseases: growing threats to plantation productivity

    African Journals Online (AJOL)

    There are also growing examples of host-specific pathogens native to areas where eucalypts have been planted as non-natives, which have undergone sometimes surprising host jumps. These 'new pathogens\\' threaten not only plantation forestry based on non-natives, but also eucalypts and their relatives in areas where ...

  12. Homeschooling: A Growing Option in American Education. Backgrounder. No. 2122

    Science.gov (United States)

    Lips, Dan; Feinberg, Evan

    2008-01-01

    A growing number of American families are choosing to homeschool their children. While research evidence is limited, evaluations of student outcomes suggest that homeschooling is successful for participating students: They do well in their learning environment, perform as well on national college assessment tests as traditional high school…

  13. Growing evidence for human health benefits of boron

    Science.gov (United States)

    Growing evidence from numerous laboratories using a variety of experimental models shows that boron is a bioactive beneficial, perhaps essential, element for humans. Reported beneficial actions of boron include arthritis alleviation or risk reduction; bone growth and maintenance; central nervous sys...

  14. Growing up with short stature : Psychosocial consequences of hormone treatment

    NARCIS (Netherlands)

    Visser-van Balen, J.

    2007-01-01

    Growing up with short stature. Psychosocial consequences of hormone treatment To enhance height in children with short stature, growth hormone (GH) can be used. In short children without a detectable pathology underlying their short stature, there is no medical rationale for growth hormone

  15. Neonatal airway obstruction caused by rapidly growing nasopharyngeal teratoma.

    NARCIS (Netherlands)

    Maartens, I.A.; Wassenberg, T.; Halbertsma, F.J.; Marres, H.A.M.; Andriessen, P.

    2009-01-01

    A case report is presented of a rapidly growing congenital nasopharyngeal teratoma (epignathus) in a preterm infant, leading to severe upper airway obstruction. Prenatal diagnosis by ultrasonography did not reveal the condition because the tumour masses were initially small and there was no

  16. Project GROW [Green River Opportunities for Work]: Final Report.

    Science.gov (United States)

    Vikers, Theo; Gibson, Melvin Pat

    Summarizing the progress of Project Green River Opportunities for Work (Project GROW), the document reviews the study's background and the activities resulting from a third party evaluation by the Southern Association of Colleges and Schools. Objectives based on the evaluation and recommendations included: (1) development of an articulated and…

  17. Influence of cutting growing cassava (Manihot esculenta Crantz)

    African Journals Online (AJOL)

    Influence du prélèvement des boutures de manioc (Manihot esculenta Crantz) en cours de vegetation sur la sévérité des maladies et ravageurs : Influence of cutting growing cassava (Manihot esculenta Crantz) plants on the severity of pests and diseases.

  18. Nursery growing of some apple varieties using different grafting ...

    African Journals Online (AJOL)

    This study was carried out at the Eğirdir Horticultural Research Institute, between the years 2006 and 2007. The aim of this study was to investigate the advantages of apple nursery growing greenhouse rather than outdoor medium. Scions of Red Chief (dwarf), Braeburn (semi dwarf) and Mondial Gala (vigorous) apple ...

  19. Performance characteristics of growing rabbits fed diet based on a ...

    African Journals Online (AJOL)

    A feeding trial using twenty four cross bred 8-9 weeks old rabbits was conducted to investigate the effect of feeding cerelac waste - CW (a by-product of the infant food industry considered as waste) on the performance and organ characteristics of growing rabbits. Three experimental diets were formulated with diet 1 serving ...

  20. Growing degree day and sunshine radiation effects on peanut pod ...

    African Journals Online (AJOL)

    Growth and development of peanut (Arachis hypogaea L.) are affected by different uncontrollable environmental conditions. The objective of this work was to investigate the effect of different planting dates, thermal temperatures (growing degree days, GDD) and daily sunshine duration on morphological and agronomic traits ...

  1. Carryover of cadmium from feed in growing pigs

    NARCIS (Netherlands)

    Hoogenboom, L.A.P.; Hattink, J.; Polanen, van A.; Oostrom, van J.J.; Verbunt, J.T.; Traag, W.A.; Kan, K.A.; Eijkeren, J.C.H.; Boeck, de G.; Zeilmaker, M.J.

    2015-01-01

    Growing male pigs were exposed to cadmium (Cd) at levels around 1 and 10 mg kg–1 feed for up to 12 weeks, administered as CdCl2 or Cd-cysteine (CdCys). Pigs exposed to 10 mg kg–1 showed decreased growth during the last 3 weeks. Liver and kidney concentrations of Cd continuously increased over the

  2. Fungus-Growing Termites Originated in African Rain Forest

    DEFF Research Database (Denmark)

    Aanen, Duur Kornelis; Eggleton, Paul

    2005-01-01

    extant savanna species are found in most genera, this moreover suggests that the savanna has repeatedly been colonized by fungus-growing termites. Furthermore, at least four independent "out-of-Africa" migrations into Asia, and at least one independent migration to Madagascar, have occurred. Although...

  3. The growing informalisation of work: Challenges for labour – recent ...

    African Journals Online (AJOL)

    Informalisation is characterised by workers shifting from permanent employment to casual employment and fixed-term contracts, outsourcing and employment through labour brokers. These forms of employment are accompanied by growing insecurity of employment, the undermining of basic conditions of employment, the ...

  4. Growth And Some Carcass Characteristics Of Growing Pigs Fed Full ...

    African Journals Online (AJOL)

    Thirty-six Large White X Landrace growing pigs were randomly allotted in a 3 x 3 factorial arrangement. The two dietary variables were protein source (Fish meal - FM, Chicken offal meal-COM and full·fat soybean - FFSB) and processing time of FFSB (30, 60, 90 minutes). Pigs on 90 minutes processed FFSB performed ...

  5. Growing Informal Cities: Mobile Entrepreneurs and Inclusive Growth ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Growing Informal Cities: Mobile Entrepreneurs and Inclusive Growth in South Africa, Mozambique, and Zimbabwe. Migrant entrepreneurs are an important force in the informal economy in southern Africa, but their role is often invisible to policymakers and researchers. New research on the contributions of these migrant ...

  6. Algorithm For A Self-Growing Neural Network

    Science.gov (United States)

    Cios, Krzysztof J.

    1996-01-01

    CID3 algorithm simulates self-growing neural network. Constructs decision trees equivalent to hidden layers of neural network. Based on ID3 algorithm, which dynamically generates decision tree while minimizing entropy of information. CID3 algorithm generates feedforward neural network by use of either crisp or fuzzy measure of entropy.

  7. "Growing trees backwards": Description of a stand reconstruction model

    Science.gov (United States)

    Jonathan D. Bakker; Andrew J. Sanchez Meador; Peter Z. Fule; David W. Huffman; Margaret M. Moore

    2008-01-01

    We describe an individual-tree model that uses contemporary measurements to "grow trees backward" and reconstruct past tree diameters and stand structure in ponderosa pine dominated stands of the Southwest. Model inputs are contemporary structural measurements of all snags, logs, stumps, and living trees, and radial growth measurements, if available. Key...

  8. The suitability evaluation of lignocellulosic substrate as growing ...

    African Journals Online (AJOL)

    The use of peat moss (PM) as a growing media is decreasing due to high costs and environmental considerations. Therefore, diverse waste products are being used as organic amendments in certain soils before afforestation. The main objective of this work was to identify and evaluate possible substrate alternatives or ...

  9. Overcrowding of accident & emergency units: is it a growing concern ...

    African Journals Online (AJOL)

    Background: The inability of the Nigeria's Accident and Emergency Departments (AED) to meet current demands is growing among the public and health care professionals. The data supporting perceptions of insufficient capacity are limited. Therefore, this study was intended to determine the prevalence, causes, and ...

  10. Growing small youth businesses in Kenya | CRDI - Centre de ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Youth make up a third of Kenya's population. Up to 35% of them are unemployed or work in informal micro-enterprises. Rachel Kalbfleisch, a 2016 IDRC Research Award recipient, wanted to know more about their ambitions and whether these youth planned to grow their businesses.

  11. Environmental and Social Programmes and Rapidly Growing Retailers

    Directory of Open Access Journals (Sweden)

    Peter JONES

    2014-06-01

    Full Text Available This paper looks to provide an exploratory review of the extent to which the world’s fastest growing retailers are publicly reporting on their environmental and social commitments and programmes. The paper begins with an outline discussion of corporate environmental and social programmes and on public reporting processes. The paper draws its empirical material from the most recent information on environmental and social commitments and programmes posted on the world’s top twenty fastest growing retailers’ corporate web sites. While the majority of the world’s top twenty fastest growing retailers provide some public information on their commitment to environmental and social programmes there is marked variation in the extent, the nature and the detail of that information. The findings suggest that the integration of environmental and social programmes is not one of the hallmarks of rapidly growing retailers and in part this reflects the fact that many of the selected retailers are trading within emergent markets where price and availability are the principal factors driving consumer buying behaviour.

  12. Systems design methodology to develop chrysanthemum growing systems

    NARCIS (Netherlands)

    Blok, C.; Vermeulen, T.

    2012-01-01

    When chrysanthemum growers change soil for a soilless growing system they aim for labour cost reduction, quality and yield improvement and reduced emissions of nutrients. Because many attempts to come up with a viable soilless system failed, improvements and systemizations of the design process were

  13. Phylogenetic origins of the plant mitochondrion based on a comparative analysis of 5S ribosomal RNA sequences

    Science.gov (United States)

    Villanueva, E.; Delihas, N.; Luehrsen, K. R.; Fox, G. E.; Gibson, J.

    1985-01-01

    The complete nucleotide sequences of 5S ribosomal RNAs from Rhodocyclus gelatinosa, Rhodobacter sphaeroides, and Pseudomonas cepacia were determined. Comparisons of these 5S RNA sequences show that rather than being phylogenetically related to one another, the two photosynthetic bacterial 5S RNAs share more sequence and signature homology with the RNAs of two nonphotosynthetic strains. Rhodobacter sphaeroides is specifically related to Paracoccus denitrificans and Rc. gelatinosa is related to Ps. cepacia. These results support earlier 16S ribosomal RNA studies and add two important groups to the 5S RNA data base. Unique 5S RNA structural features previously found in P. denitrificans are present also in the 5S RNA of Rb. sphaeroides; these provide the basis for subdivisional signatures. The immediate consequence of obtaining these new sequences is that it is possible to clarify the phylogenetic origins of the plant mitochondrion. In particular, a close phylogenetic relationship is found between the plant mitochondria and members of the alpha subdivision of the purple photosynthetic bacteria, namely, Rb. sphaeroides, P. denitrificans, and Rhodospirillum rubrum.

  14. Carbon Isotope Fractionation during Catabolism and Anabolism in Acetogenic Bacteria Growing on Different Substrates.

    Science.gov (United States)

    Freude, Christoph; Blaser, Martin

    2016-05-01

    Homoacetogenic bacteria are versatile microbes that use the acetyl coenzyme A (acetyl-CoA) pathway to synthesize acetate from CO2 and hydrogen. Likewise, the acetyl-CoA pathway may be used to incorporate other 1-carbon substrates (e.g., methanol or formate) into acetate or to homoferment monosaccharides completely to acetate. In this study, we analyzed the fractionation of pure acetogenic cultures grown on different carbon substrates. While the fractionation of Sporomusa sphaeroides grown on C1 compounds was strong (εC1, -49‰ to -64‰), the fractionation of Moorella thermoacetica and Thermoanaerobacter kivui using glucose (εGlu= -14.1‰) was roughly one-third as strong, suggesting a contribution of less-depleted acetate from fermentative processes. ForM. thermoacetica, this could indeed be validated by the addition of nitrate, which inhibited the acetyl-CoA pathway, resulting in fractionation during fermentation (εferm= -0.4‰). In addition, we determined the fractionation into microbial biomass of T. kivui grown on H2/CO2(εanabol.= -28.6‰) as well as on glucose (εanabol.= +2.9‰). Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  15. Bioaccumulation of cadmium by growing Zygosaccharomyces rouxii and Saccharomyces cerevisiae.

    Science.gov (United States)

    Li, Chunsheng; Jiang, Wei; Ma, Ning; Zhu, Yinglian; Dong, Xiaoyan; Wang, Dongfeng; Meng, Xianghong; Xu, Ying

    2014-03-01

    Bioaccumulation via growing cells is a potential technique for heavy metal removal from food materials. The cadmium bioaccumulation characteristics by growing Zygosaccharomyces rouxii and Saccharomyces cerevisiae were investigated. Z. rouxii displayed powerful cadmium removal ability at low cadmium concentrations, which mainly depended on the intracellular cadmium bioaccumulation. The percentage of intracellular cadmium bioaccumulation of both yeasts obviously decreased with the increase of initial biomass and cadmium concentrations. Low pH and elevated concentrations of zinc and copper significantly decreased the intracellular cadmium bioaccumulation of both yeasts but improved the cadmium tolerance and the cell-surface cadmium bioaccumulation of Z. rouxii. Cadmium removal of Z. rouxii was improved by zinc and copper conditionally. Z. rouxii that possessed more powerful cadmium tolerance and removal ability at low pH and high concentration of competing ions can be developed into a potential cadmium removal agent using in complex food environment in future. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Faba beans in diets for growing-finishing pigs

    Directory of Open Access Journals (Sweden)

    K. PARTANEN

    2008-12-01

    Full Text Available Two experiments were carried out to study the effects of using the new faba bean (Vicia faba L. cultivar Kontu as a domestic protein source for growing-finishing pigs.In Experiment 1,120 pigs were used with a body weight (BWof 25–110 kg to study the effects of replacing 0, 25, 50, 75,and 100%of rapeseed meal with faba beans in barley +rapeseed meal based diets. Restrictedly fed grower and finisher diets contained 137–317 and 114–260 g kg–1 faba beans, respectively. A barley +soya bean meal based diet was included as a control. The replacement of rapeseed meal with faba beans exerted a quadratic effect on daily weight gain and on the feed conversion ratio of pigs in the growing period and during total fattening (P

  17. Near tip strain evolution of a growing fatigue crack

    Directory of Open Access Journals (Sweden)

    M.-L. Zhu

    2015-07-01

    Full Text Available Near tip full-field strains in a growing fatigue crack have been studied in situ using the Digital Image Correlation (DIC technique in a compact tension specimen of stainless steel 316L under tension-tension cyclic loading. An error analysis of displacements and strains has been carried out, and the results show that the precision of displacements and strains in the wake of the crack is worse than that in front of the crack. A method for the determination of crack tip location is proposed for the DIC analysis. Strain ratchetting is observed ahead of the growing fatigue crack tip and found to be dependent on the distance to the crack tip; whilst normal strains appear to stabilise behind the crack tip.

  18. Structure analysis of growing network based on partial differential equations

    Directory of Open Access Journals (Sweden)

    Junbo JIA

    2016-04-01

    Full Text Available The topological structure is one of the most important contents in the complex network research. Therein the node degree and the degree distribution are the most basic characteristic quantities to describe topological structure. In order to calculate the degree distribution, first of all, the node degree is considered as a continuous variable. Then, according to the Markov Property of growing network, the cumulative distribution function's evolution equation with time can be obtained. Finally, the partial differential equation (PDE model can be established through distortion processing. Taking the growing network with preferential and random attachment mechanism as an example, the PDE model is obtained. The analytic expression of degree distribution is obtained when this model is solved. Besides, the degree function over time is the same as the characteristic line of PDE. At last, the model is simulated. This PDE method of changing the degree distribution calculation into problem of solving PDE makes the structure analysis more accurate.

  19. MELNIK VINE-GROWING REGION – HISTORY AND TRADITIONS

    Directory of Open Access Journals (Sweden)

    Radoslava Ganeva

    2017-06-01

    Full Text Available The region of Melnik (Southwest Bulgaria has exclusively appropriate climate for wine growing. Its borders are defined by the dissemination of the wide Melnik grape vine, revealed by experts as an old local variety. Few are the wine-growing centers that carry such an effective ampelographic tradition. A few are the viticulture centers, bearing such effective tradition. The vine is grown here from the Thracian antiquity and is the basis for a livelihood, preserved and retransmitted for many generations. It is characterized by a specialization in the production and marketing of high quality red dry wines. The article deals with the development of the Melnik vineyard as a result of different political and economic conditions in the course of historical development. Various archival materials, specialized studies and personal fieldwork research have been used.

  20. Identification and assessment of the slowly growing child.

    Science.gov (United States)

    Duck, S C

    1996-05-15

    Reliable measurements taken by trained personnel using appropriate equipment are essential in assessment of the slowly growing child. Linear growth plotted on appropriate statistical charts and expected growth based on parental heights are indicators of inappropriately reduced linear growth. Children older than three years of age who grow less than 1.75 in (4.5 cm) per year should be evaluated. Family and personal medical history (including prenatal and birth information) are important in the identification of familial short stature, constitutional delay and other causes of proportionate growth disorders. Other conditions, including chromosomal disorder, systemic disease and endocrine dysfunction, may be discovered during physical examination or appropriate laboratory investigation. Disproportionate growth of the limbs and trunk suggests the presence of a bone or collagen disorder. Bone age data based on radiographs of the left hand may assist in predicting the child's final height.

  1. Rotary forcespun styrofoam fibers as a soilless growing medium

    Science.gov (United States)

    Fauzi, Ahmad; Edikresnha, Dhewa; Munir, Muhammad Miftahul; Khairurrijal

    2016-04-01

    To make styrofoam fibers from used styrofoam, rotary forcespinning technique was used because it offers high production rate and affordable production cost. The used styrofoam was dissolved in acetone to obtain styrofoam solution as a precursor of syrofoam fibers. Since the technique utilizes centrifugal force, the precursor was thrown out and its phase changed to be solid following acetone solvent evaporation. Long, clean and light styrofoam fibers were then produced. To determine if the styrofoam fibers is a good soilless growing medium, physico-chemical properties including pH and electrical conductivity, bulk density, water retention and wettability were measured. Rockwool, which is the most popular soilless growing medium and easily obtained from local farm suppliers, was selected as a benchmark to evaluate the styrofoam fibers.

  2. China’s growing role in the South Atlantic

    Directory of Open Access Journals (Sweden)

    Adriana Erthal Abdenur

    2013-09-01

    Full Text Available Over the past decade, the flow of goods, people and ideas across the South Atlantic has increased considerably, due not only to growing trade and cooperation ties between South America and Africa, but also to the new interests of extra-regional emerging powers such as the People’s Republic of China. This article examines China’s growing role in the region in three different spheres (economic, political andsecurity interests in light of its changing strategy in developing countries; the role of non-state actors such as corporations and diaspora communities is also included. The authors conclude that, even though the Chinese state does not yet have a “South Atlantic policy”, the region has gained strategic importance for China. Finally, the article highlights China’s renewed interest in Antarctica.

  3. Towards Automatic Image Segmentation Using Optimised Region Growing Technique

    Science.gov (United States)

    Alazab, Mamoun; Islam, Mofakharul; Venkatraman, Sitalakshmi

    Image analysis is being adopted extensively in many applications such as digital forensics, medical treatment, industrial inspection, etc. primarily for diagnostic purposes. Hence, there is a growing interest among researches in developing new segmentation techniques to aid the diagnosis process. Manual segmentation of images is labour intensive, extremely time consuming and prone to human errors and hence an automated real-time technique is warranted in such applications. There is no universally applicable automated segmentation technique that will work for all images as the image segmentation is quite complex and unique depending upon the domain application. Hence, to fill the gap, this paper presents an efficient segmentation algorithm that can segment a digital image of interest into a more meaningful arrangement of regions and objects. Our algorithm combines region growing approach with optimised elimination of false boundaries to arrive at more meaningful segments automatically. We demonstrate this using X-ray teeth images that were taken for real-life dental diagnosis.

  4. Circumferential buckling instability of a growing cylindrical tube

    KAUST Repository

    Moulton, D.E.

    2011-03-01

    A cylindrical elastic tube under uniform radial external pressure will buckle circumferentially to a non-circular cross-section at a critical pressure. The buckling represents an instability of the inner or outer edge of the tube. This is a common phenomenon in biological tissues, where it is referred to as mucosal folding. Here, we investigate this buckling instability in a growing elastic tube. A change in thickness due to growth can have a dramatic impact on circumferential buckling, both in the critical pressure and the buckling pattern. We consider both single- and bi-layer tubes and multiple boundary conditions. We highlight the competition between geometric effects, i.e. the change in tube dimensions, and mechanical effects, i.e. the effect of residual stress, due to differential growth. This competition can lead to non-intuitive results, such as a tube growing to be thinner and yet buckle at a higher pressure. © 2011 Elsevier Ltd. All rights reserved.

  5. Design of growing points for silver nanoparticles on polypropylene membranes

    Science.gov (United States)

    Mendieta-Jiménez, Ana L.; Carpio-Martínez, Pablo; Cortés-Guzmán, Fernando; Gómez-Espinosa, Rosa María

    2018-02-01

    The nucleation process of a nanoparticle requires an environment that stabilizes the initial seed and favors the growth action. In this paper, we present a specific design of growing points for silver nanoparticles based on the well-known affinity of the silver to the chlorine atoms and to aromatic groups by cation-π interactions. [2-(vinylphenyl)ethyl]chloromethylphenylsilane was proposed as growing point of nanoparticles, which has been synthetized and grafted on a polypropylene membrane. Nanoparticles were synthesized by chemically reducing an AgNO3 solution with NaBH4 and the so synthesized nanoparticles were also fully characterized. Using DFT-QTAIM calculations a model of the initial seed and a growth mechanism were proposed.

  6. SAR Imagery Segmentation by Statistical Region Growing and Hierarchical Merging

    Energy Technology Data Exchange (ETDEWEB)

    Ushizima, Daniela Mayumi; Carvalho, E.A.; Medeiros, F.N.S.; Martins, C.I.O.; Marques, R.C.P.; Oliveira, I.N.S.

    2010-05-22

    This paper presents an approach to accomplish synthetic aperture radar (SAR) image segmentation, which are corrupted by speckle noise. Some ordinary segmentation techniques may require speckle filtering previously. Our approach performs radar image segmentation using the original noisy pixels as input data, eliminating preprocessing steps, an advantage over most of the current methods. The algorithm comprises a statistical region growing procedure combined with hierarchical region merging to extract regions of interest from SAR images. The region growing step over-segments the input image to enable region aggregation by employing a combination of the Kolmogorov-Smirnov (KS) test with a hierarchical stepwise optimization (HSWO) algorithm for the process coordination. We have tested and assessed the proposed technique on artificially speckled image and real SAR data containing different types of targets.

  7. Utilization Of Cassava and Pawpaw Diets By Growing Snails ...

    African Journals Online (AJOL)

    Two hundred and twenty five (225) growing snails of an average weight of 70g were used for the feeding trial, with five dietary treatments. The trial lasted fourteen weeks. The diets were isonitrogenous (18.30% crude protein) and Isocaloric (2500kcal/kg M. E). The treatments were T1, T2, T3, T4 and T5. The rations had 10% ...

  8. Assessment of selected native plants growing along Nairobi river for ...

    African Journals Online (AJOL)

    Assessment of selected native plants growing along Nairobi river for uptake of copper, zinc and cadmium. ... 0.74 mg/Kg, Zn 16.53 ± 2.59 mg/Kg and Cd 2.57 ± 0.83 mg/Kg. Based on the results observed in the plants, Zn showed the largest accumulation and can be considered as one of the major pollutants of Nairobi River.

  9. Closed soilless growing systems in the Netherlands: the finishing touch

    OpenAIRE

    Os, van, E.A.

    1998-01-01

    This paper gives an overview of the latest developments in closed soilless growing systems in the Netherlands, where growers are obliged to invest in environmently friendly cropping systems, in order to comply with new legislation. Subjects of discussion will be the reasons for regulation, the growers' reaction to the proposed legislation, the methods to comply with legislation and related problems such as the availability of good water, the systems applied and the developments in the disinfe...

  10. Growing bacteria shed elicitors of Drosophila humoral immunity.

    Science.gov (United States)

    Karlsson, Jenny; Oldenvi, Sandra; Fahlander, Carina; Daenthanasanmak, Anusara; Steiner, Håkan

    2012-01-01

    It has been much debated how the Drosophila immune system can recognize bacterial peptidoglycan that is often hidden. We show that bacteria separated from Drosophila S2 cells by a semipermeable membrane can upregulate the Imd pathway. Supernatants from exponentially growing but not from stationary-phase bacterial cultures induce antimicrobial peptides. It is also made likely that the shed elicitors are of peptidoglycan nature. Copyright © 2011 S. Karger AG, Basel.

  11. Multifork chromosome replication in slow-growing bacteria

    OpenAIRE

    Damian Trojanowski; Joanna Hołówka; Katarzyna Ginda; Dagmara Jakimowicz; Jolanta Zakrzewska-Czerwińska

    2017-01-01

    The growth rates of bacteria must be coordinated with major cell cycle events, including chromosome replication. When the doubling time (Td) is shorter than the duration of chromosome replication (C period), a new round of replication begins before the previous round terminates. Thus, newborn cells inherit partially duplicated chromosomes. This phenomenon, which is termed multifork replication, occurs among fast-growing bacteria such as Escherichia coli and Bacillus subtilis. In contrast, it ...

  12. From Kennedy, to Beyond: Growing Plants in Space

    Science.gov (United States)

    Flemming, Cedric, II; Seck, Sokhana A.; Massa, Gioia D.; Hummerick, Mary E.; Wheeler, Raymond

    2012-01-01

    Astronauts cannot have their cake and eat it too, but what about growing a salad and eating it? As NASA continues to push the envelope on Space exploration and inhabitance the need for a fresh food source becomes more vital. The Life Support team at NASA is using a system developed by ORBITEC the VEGGIE, in which astronauts aboard the ISS, and potentially the Moon and Mars, will be capable of growing food. The introduction of plants not only gives astronauts a means of independently supplying food, but also recreation, oxygen replenishment and psychological benefits. The plants were grown in "pillows", the system used for growing plants within the VEGGIE. This test included 4 types of media mixtures that are composed of a clay based media called Arcilite and Fafard #2, which is a peat moss-based media ( <1 mm Arcilite, 1-2 mm of Arcilite, 1:1 <1 mm & 1-2 mm mixture and 1:1 Arcilite & Fafard mixture). Currently, 3 lettuce cultivars are being grown in 4 mixtures of media. Tests were being conducted to see which form of media has the ratio of best growth and least amount of microbes that are harmful. That is essential because a person's body becomes more susceptible to illness when they leave Earth. As a result, test must be conducted on the "pillow" system to assess the levels of microbial activity. The cultivars were tested at different stages during their growing process for microbes. Datum show that the mix of Fafard and Arcilite had the best growth, but also the most microbes. This was due to the fact that Fafard is an organic substance so it contains material necessary for microbes to live. Data suggest that the <1 mm Arcilite has an acceptable amount of growth and a lower level of microbes, because it is non-organic.

  13. The apple, the tree, and a space to grow in

    DEFF Research Database (Denmark)

    Rezaei, Shahamak

    2017-01-01

    is known about young people of foreign origin growing up as immigrant residents in Europe, despite their significant number (10 per cent in France, 13 per cent in Spain and 15 per cent in Ireland by 2010). The success or failure of immigrants’ integrational processes, considering cultural factors...... and language barriers as challenges experienced by immigrants, can have major political and social impact on the regions where they reside. It is these challenges that are investigated in depth, in this book....

  14. VEGETABLE GROWING - HOBBY AND BENEFIT FOR AGED PERSON HEALTH

    OpenAIRE

    Scurtu Ion

    2015-01-01

    Vegetable growing in small areas (open field, plastic tunnels, unheated or heated green house or even in balcony) may be a very pleasant activity for many old persons who want to preserve their physical and mental health. Beside many common vegetable species like tomatoes, pepper, eggplant, onion, garlic, cabbage, cucumber, lettuce and so on - can be cultivated in small areas many others vegetables like broccoli, Brussels cabbage, Scorzonera hispanica, asparagus, Witloof Chicory (French endiv...

  15. Influence of growing and exploatation of bovins on regional agroecosystems

    OpenAIRE

    Cornel Podar; Ioan Oroian; Friss Zsuzsa; Bianca Damian; I. Macarie; Daniela Ţerbea; Pop, Ioan A

    2011-01-01

    Scientists all over the are concerned regarding the influence of growing ruminants on regional agro-ecosystems due to green house gases resulted (CO 2, CH4, N2O5). Cattle have contributed to environmental pollution in old industrial farming systems, when the cattle number in Romania, reached 8 million, manure evacuation was not solved and manure was accumulating around the farm polluting the soil, water and air. Low density of ruminants existing in the agricultural sector of the country is no...

  16. Growth performance, carcass and organ characteristics of growing ...

    African Journals Online (AJOL)

    Growth performance, carcass and organ characteristics of growing rabbits fed graded levels of Moringa oleifera leaf meal in diets. ... Similarly, the weight of liver (40.35-57.05g), lungs (10.22-11.24g), heart (2.95-4.10g), kidney (8.30-10.70g), kidney fat (11.10-12.65g), small intestine (81.25-99.80g), large intestine ...

  17. Can the Indian Navy respond to a growing Chinese fleet?

    OpenAIRE

    Quidachay, VIncent J.

    1995-01-01

    The purpose of this thesis is to determine whether the Indian Navy can respond to a growing Chinese fleet by analyzing the historical development of the Indian Navy since independence. Three naval expansion periods are identified, and three causal factors are measured to determine the effects of each factor on Indian naval expansion. The three factors are (1) responses to a perceived threat, (2) India's economic condition, and (3) the benefits of foreign military aid. The saidy shows that res...

  18. Three-dimensional CT image segmentation by volume growing

    Science.gov (United States)

    Zhu, Dongping; Conners, Richard W.; Araman, Philip A.

    1991-11-01

    The research reported in this paper is aimed at locating, identifying, and quantifying internal (anatomical or physiological) structures, by 3-D image segmentation. Computerized tomography (CT) images of an object are first processed on a slice-by-slice basis, generating a stack of image slices that have been smoothed and pre-segmented. The image smoothing operation is executed by a spatially adaptive filter, and the 2-D pre-segmentation is achieved by a thresholding process whereby each individual pixel in the input image space is consistently assigned a label, according to its CT number, i.e., the gray-level value. Given a sequence of pre-segmented images as 3-D input scene (a stack of image slices), the spatial connectivity that exists among neighboring image pixels is utilized in a volume growing process which generates a number of well-defined volumetric regions or image solides, each representing an individual anatomical or physiological structure in the input scene. The 3-D segmentation is implemented using a volume growing process so that the aspect of pixel spatial connectivity is incorporated into the image segmentation procedure. To initialize the volume growing process for each volumetric region in the input 3-D scene, a seed location for a region is defined and loaded into a queue data structure called seed queue. The volume growing process consists of a set of procedures that perform different operations on the volumetric data of a CT image sequence. Examples of experiment of the described system with CT image data of several hardwood logs are given to demonstrate usefulness and flexibility of this approach. This allows solutions to industrial web inspection, as well as to several problems in medical image analysis where low-level image segmentation plays an important role toward successful image interpretation tasks.

  19. VEGETABLE GROWING - HOBBY AND BENEFIT FOR AGED PERSON HEALTH

    Directory of Open Access Journals (Sweden)

    Scurtu Ion

    2015-07-01

    Full Text Available Vegetable growing in small areas (open field, plastic tunnels, unheated or heated green house or even in balcony may be a very pleasant activity for many old persons who want to preserve their physical and mental health. Beside many common vegetable species like tomatoes, pepper, eggplant, onion, garlic, cabbage, cucumber, lettuce and so on - can be cultivated in small areas many others vegetables like broccoli, Brussels cabbage, Scorzonera hispanica, asparagus, Witloof Chicory (French endive and vegetable with medicinal properties.

  20. The growth performance of growing pigs during feed restriction and ...

    African Journals Online (AJOL)

    Thirty two crossbred (large white x landrace) pigs were used in a 56 days restriction and 56 days realimentation study to evaluate the effect of restricting growing pigs at 90, 80 and 70% of the ad libitum feed intake of the control. The pigs averaged 35.23 ± 0.560 kg at the start of the study. There were four treatments (control, ...

  1. Effect of Cobalt Supplementation on Performance of growing Calves

    Directory of Open Access Journals (Sweden)

    V.Nagabhushana

    Full Text Available The experiment was conducted to study the effect of critical supplementation of wheat straw with cobalt on fibre utilization and nutrient utilization in growing cross-bred male calves. Twenty-one crossbred (HF X Local male growing calves of 3-4 months age were fed with wheat straw based diet consisting without (Co0 and with 1 (Co1 and 6 (Co6 ppm cobalt as cobaltous chloride. There was no significant difference in intake of wheat straw, concentrate and DMI between the three groups and the ratio between concentrate and wheat straw was maintained at 40:60 irrespective of dietary level of cobalt. Similarly, average cumulative body weight, net gain in body weight or feed efficiency did not differ significantly between treatments. No significant effect was observed on the digestibility of dry matter, organic matter, crude protein, ether extract and fibre constituents like NDF, ADF, hemicellulose or cellulose by supplementation of 1 and 6 ppm Co to the diet of growing calves. Balance of nutrients such as Nitrogen, Calcium and Phosphorus was similar and positive in all the treatment groups. TDN and DCP values of the experimental diets remained almost similar irrespective of dietary level of cobalt. [Veterinary World 2008; 1(10.000: 299-302

  2. DEMANDING NEED OF GROWING TECHNOLOGIES IN DISTANCE LEARNING SYSTEM

    Directory of Open Access Journals (Sweden)

    Amtul HAFEEZ

    2014-10-01

    Full Text Available In distance education system use of different media enable the learners to start the course of study independently. The appearance of the internet and the expansion of web have now changed distance learning from a broadcasting way to an interactive way, and allowed connecting the learners and instructors who are geographically divided. Technological advances have created a paradigm shift in education and the definition of distance learning, as described by James Morrison (1996, who states that telecommunications, software, and the Internet eliminate walls and boundaries. In addition, he states that an increasing number of students want and need non-traditional, flexible schedules. Main findings of the study revealed that majority of the distance learners need growing technologies to interact with the tutors and peers for academic guidance and use of latest technologies make distance learners more up to date and helpful for better academic achievements. Majority of the students agreed that without any training distance learner cannot use growing technologies. It was recommended that AIOU may take steps to organize a specific website for the MS/M.phil and Ph.D scholars so that they can easily interact with peers and tutors. A comprehensive training programme may be launched to enable the tutors for using growing technologies so that they can facilitate the learners by using latest methods of teaching. Virtual classrooms can be started along with the workshops. Students and academicians of education department may use latest technologies and internet softwares which can be helpful for academic purpose.

  3. Multifork chromosome replication in slow-growing bacteria.

    Science.gov (United States)

    Trojanowski, Damian; Hołówka, Joanna; Ginda, Katarzyna; Jakimowicz, Dagmara; Zakrzewska-Czerwińska, Jolanta

    2017-03-06

    The growth rates of bacteria must be coordinated with major cell cycle events, including chromosome replication. When the doubling time (Td) is shorter than the duration of chromosome replication (C period), a new round of replication begins before the previous round terminates. Thus, newborn cells inherit partially duplicated chromosomes. This phenomenon, which is termed multifork replication, occurs among fast-growing bacteria such as Escherichia coli and Bacillus subtilis. In contrast, it was historically believed that slow-growing bacteria (including mycobacteria) do not reinitiate chromosome replication until the previous round has been completed. Here, we use single-cell time-lapse analyses to reveal that mycobacterial cell populations exhibit heterogeneity in their DNA replication dynamics. In addition to cells with non-overlapping replication rounds, we observed cells in which the next replication round was initiated before completion of the previous replication round. We speculate that this heterogeneity may reflect a relaxation of cell cycle checkpoints, possibly increasing the ability of slow-growing mycobacteria to adapt to environmental conditions.

  4. Economic aspects of triticale growing: Australian farmer experience.

    Science.gov (United States)

    Cooper, Katharine V; Elleway, Michael G

    2014-01-01

    Australian farmers grow triticale for economic benefit. A range of farmers in different localities, with different farm size, soil type, rainfall and proximity to markets, were asked why they grew triticale and how it contributed to their farm economics. The main encouragements to grow triticale relate to its agronomic prowess: its reliability and magnitude of production on all soil types and particularly in conditions in which other crops are relatively poor producers. Also in favour of triticale is its ability to produce economic return following a high yielding wheat crop, whilst providing soil benefits as a rotation crop reducing root and stubble diseases. Triticale's versatility and utility as high grade animal feed, by supplying grazing, fodder for conservation, and grain for on-farm animal production, further encourages farmers to include triticale in their cropping programs. The main inhibitor to growing triticale relates to the cost and ease of marketing the product, relative to other crops, and even triticale enthusiasts do not persist with triticale, if the economics are not in its favour. A downturn in the dairy industry, and the cessation of triticale grain receivals at bulk handling sites has resulted in a contraction of triticale production in some regions. Less triticale is likely to be grown where farmers have to provide their own storage, find their own markets, freight the product further, or have limited market options. New specific markets, such as high grade hay from reduced-awn triticale varieties, for the horse industry, may increase the profitability of triticale producing enterprises.

  5. Biorock Electric Reefs Grow Back Severely Eroded Beaches in Months

    Directory of Open Access Journals (Sweden)

    Thomas J. F. Goreau

    2017-10-01

    Full Text Available Severely eroded beaches on low lying islands in Indonesia were grown back in a few months—believed to be a record—using an innovative method of shore protection, Biorock electric reef technology. Biorock shore protection reefs are growing limestone structures that get stronger with age and repair themselves, are cheaper than concrete or rock sea walls and breakwaters, and are much more effective at shore protection and beach growth. Biorock reefs are permeable, porous, growing, self-repairing structures of any size or shape, which dissipate wave energy by internal refraction, diffraction, and frictional dissipation. They do not cause reflection of waves like hard sea walls and breakwaters, which erodes the sand in front of, and then underneath, such structures, until they collapse. Biorock reefs stimulate settlement, growth, survival, and resistance to the environmental stress of all forms of marine life, restoring coral reefs, sea grasses, biological sand production, and fisheries habitat. Biorock reefs can grow back eroded beaches and islands faster than the rate of sea level rise, and are the most cost-effective method of shore protection and adaptation to global sea level rise for low lying islands and coasts.

  6. RESTRICTIVE FACTORS FOR FRUIT - GROWING USE ON TERRAINS WITHIN THE SÂRCA FRUIT-GROWING BASIN

    Directory of Open Access Journals (Sweden)

    Gabriela Boronia

    2010-10-01

    Full Text Available From the the analysis of physical and chemical characteristics of the soil, of some climatic and hydrological elements as well as some environmental specific factors such as drainage, surface erosion, gradient, inundability etc, result a number of limiting factors (deficiencies of the agricultural terrains, which determine certain restrictions in their use for fruit-growing. Restrictions are refered to natural factors that impose crop limitations, but also the danger of anthropic reductions through exploition with similar effects, but a differential impact. This paper aims at presenting the main terrain limiting factors, following restrictions imposed by relief, climate, pedologic and hydrological conditions (terrain constitutive elements. On the other hand, factors that generate deficiencies in fruit-growing plantations have also been considered: reduced growth, slow fruition, and slow root system development, growth and fructification cycle shortening lead to crop reductions.

  7. Growing Up in Poverty, Growing Old in Infirmity: The Long Arm of Childhood Conditions in Great Britain.

    Directory of Open Access Journals (Sweden)

    Gindo Tampubolon

    Full Text Available The ageing population poses a tremendous challenge in understanding the sources of inequalities in health. Though they appear to be far removed, childhood conditions are known to be inextricably linked with adult health, and in turn on health in later life. The long arm of childhood conditions hypothesis is often tested using recollection of childhood circumstances, but such subjective recall can yield potentially inaccurate or possibly biased inferences. We tested the long arm hypothesis on three outcomes in later life, arrayed from objective to subjective health, namely: gait speed, episodic memory and mental health.We used the English Longitudinal Study of Ageing 2006 enriched with retrospective life history (N = 5,913. To deal with recall problems two solutions, covariate measurement and endogenous treatment models, were applied. Retrospective childhood material lack includes growing up without running hot or cold water, fixed bath, indoor lavatory and central heating. Adjustment is made for an extensive set of confounders including sex, age, adult health, wealth, education, occupation, social support, social connections, chronic conditions, smoking, drinking, and physical exercise. It is found that material poverty when growing up shows no association with health when growing old, assuming accurate recall. Once recall problems are controlled, we found that childhood material poverty changes inversely with later life health.A poorer childhood goes with slower gait, poorer memory and more depression in later life. This result provides a further impetus to eliminate child poverty.

  8. Impact of porcine epidemic diarrhea on performance of growing pigs.

    Directory of Open Access Journals (Sweden)

    Julio Alvarez

    Full Text Available The impact of porcine epidemic diarrhea virus (PEDv infection on the US pork industry has mainly been attributed to the mortality that it causes in suckling piglets, and, consequently, much effort has been invested in the quantification of its effect in sow farms. However, no information on the performance of surviving pigs that were exposed to the PEDv as piglets is available. Here, a retrospective cohort study to evaluate the impact of porcine epidemic diarrhea virus (PEDv infection on growing pigs' performance, as indicated by mortality, average daily gain (ADG, average daily feed intake (ADFI, and feed conversion ratio (FCR was performed using production records from weaned pigs in nursery and wean-to-finish sites from sow farms that became PEDv-infected between May 2013 and June 2014. Production records from the first batch of growing pigs weaned in infected flows after the PEDv outbreak ("infected batches" were compared with those from pigs weaned within the previous 14 to 120 days ("control batches". Performance records from infected and control batches, paired by flow, were compared using non-parametric paired tests. Mortality, ADG and FCR were significantly different in PEDv-positive (infected compared with PEDv-negative (control batches, with a mean increase of mortality and FCR of 11% and 0.5, respectively, and a decrease of ADG of 0.16 lb/day. Our results demonstrate a poorer performance of growing pigs weaned after a PEDv outbreak compared with those weaned within the previous 14-120 days, suggesting that in addition to the mortality induced by PEDv in suckling pigs, the disease also impairs the performance of surviving pig. These findings help to quantify the impact of PEDv infection in the US and, ultimately, contribute to efforts to quantify the cost-effectiveness of disease prevention and control measures.

  9. Growing Mediums in Different Environments for Sunflower and Cilantro Microgreens

    Science.gov (United States)

    Tran, B.; Gonzalez, O.

    2016-12-01

    The purpose of this experiment is to investigate the growth and subsequent harvest of young seedlings known as microgreens, which have expanded into a very profitable market. The goal of the experiment is to discover whether the nutrients, soil quality and climate influences the quality, flavor, and yield of the microgreens. To conduct this experiment, locations and soil types were chosen; the locations consisted of a greenhouse (an enclosed space which held consistent sunlight, warmth, and humidity) and a lath house (a somewhat shaded location that was open to the elements as well as temperature changes), while compost, Quick Root (a growing medium that is relatively devoid of nutrients), and a combination of the two is used in this experiment. This meant that a total of six different combinations could be tested. Along with that, two different seeds were selected, sunflower seeds and cilantro seeds. Each of the results are mainly influenced by the soil type, and a partial influence by the climate. Compost has an extreme lack in growth and did not produce enough plants to record in general. The Quick Root results show only a burst of growth would occur; also, the plants did not have a strong taste, but did grow slightly quicker within the greenhouse. Another advantage to the Quick Root results is that the root size nearly tripled compared to the 50/50 root size. 50/50 holds the strongest results i.e., growth consistency and holds a stronger taste. Originally, there was an attempt to grow sunflowers uncovered, but was not attempted again due to poor results. Overall the 50/50 held a stronger growth and taste, but also would easily excel in the long run compared to the Quick Root and the compost.

  10. Fiber level for laying hens during the growing phase

    Directory of Open Access Journals (Sweden)

    Ednardo Rodrigues Freitas

    2014-04-01

    Full Text Available Feeding management of laying hens has been focused on the direct influence of nutrient intake on weight gain, especially at growing phase. This study evaluates nutrient digestibility, performance, development of the digestive tract, body composition, and bone quality of two strains of laying hens fed with different levels of neutral detergent fiber (NDF during the growing phase from the 7th to the 12th week of age. A total of 1,296 birds were distributed in a completely randomized design in a 2 x 3 factorial arrangement (two strains x three levels of NDF with four replicates of 54 birds per treatment. Semi-heavy (Hy Line Brown and light-strain (Lohman LSL pullets were allotted to dietary treatments consisting of 14.50, 16.50, and 18.50% NDF. An interaction between strains and NDF levels was observed only for feed/gain ratio and light-strain pullets had lower performance with 18.50% NDF. The increasing levels of NDF in the diet reduced the coefficients of digestibility of dry matter, nitrogen and gross energy, and the values of metabolizable energy. Higher levels of NDF in the diet increased the relative weight of liver and intestines and reduced gizzard weight. It was also observed differences between bone quality and composition of the femur and tibia of light and semi-heavy hens. The increase in NDF level in ration for growing phase laying hens above 14.50% decreases the nutrient digestibility and the metabolizable energy of the diet; however, it does not affect the carcass composition, bone quality, feed intake, and weight gain, although it may impair feed conversion of light-strain pullets.

  11. Impact of porcine epidemic diarrhea on performance of growing pigs.

    Science.gov (United States)

    Alvarez, Julio; Sarradell, Javier; Morrison, Robert; Perez, Andres

    2015-01-01

    The impact of porcine epidemic diarrhea virus (PEDv) infection on the US pork industry has mainly been attributed to the mortality that it causes in suckling piglets, and, consequently, much effort has been invested in the quantification of its effect in sow farms. However, no information on the performance of surviving pigs that were exposed to the PEDv as piglets is available. Here, a retrospective cohort study to evaluate the impact of porcine epidemic diarrhea virus (PEDv) infection on growing pigs' performance, as indicated by mortality, average daily gain (ADG), average daily feed intake (ADFI), and feed conversion ratio (FCR) was performed using production records from weaned pigs in nursery and wean-to-finish sites from sow farms that became PEDv-infected between May 2013 and June 2014. Production records from the first batch of growing pigs weaned in infected flows after the PEDv outbreak ("infected batches") were compared with those from pigs weaned within the previous 14 to 120 days ("control batches"). Performance records from infected and control batches, paired by flow, were compared using non-parametric paired tests. Mortality, ADG and FCR were significantly different in PEDv-positive (infected) compared with PEDv-negative (control) batches, with a mean increase of mortality and FCR of 11% and 0.5, respectively, and a decrease of ADG of 0.16 lb/day. Our results demonstrate a poorer performance of growing pigs weaned after a PEDv outbreak compared with those weaned within the previous 14-120 days, suggesting that in addition to the mortality induced by PEDv in suckling pigs, the disease also impairs the performance of surviving pig. These findings help to quantify the impact of PEDv infection in the US and, ultimately, contribute to efforts to quantify the cost-effectiveness of disease prevention and control measures.

  12. Growing Economic Inequality and Its (Partially Political Roots

    Directory of Open Access Journals (Sweden)

    Kay Lehman Schlozman

    2017-05-01

    Full Text Available Growing economic inequality fosters inequality in the political processes of American democracy. Since the 1970’s inequalities in earnings and wealth have increased dramatically in the United States creating a higher level of inequality in disposable income than in other developed democracies. The United States also lags behind other rich nations in the way it provides for those at the bottom of the income distribution, and there is no evidence that the opportunities for success promised by the American Dream compensate for inequality in America. Technological and economic developments are significant causes of this growing economic inequality. The role of politics is more controversial, but government policy influences the distribution of income and education by the way it determines government benefits, taxes and the way markets function. For a number of reasons—including, most importantly, the relationship between education and income and the ability of the affluent to make large campaign donations—those who are economically well-off speak more loudly in politics. They are more likely to engage in most forms of individual political participation—not only ones that involve using cash but also ones that cost nothing except time. Moreover, when it comes to political voice through organizations, a professionalized domain dominated by hired experts in which the volume of political voice can be altered to reflect available economic resources, affluent interests are more likely to be organized and active. This essay considers the growing economic inequalities that form an important part of the backdrop for unequal political voice.

  13. Identification of protein W, the elusive sixth subunit of the Rhodopseudomonas palustris reaction center-light harvesting 1 core complex.

    Science.gov (United States)

    Jackson, Philip J; Hitchcock, Andrew; Swainsbury, David J K; Qian, Pu; Martin, Elizabeth C; Farmer, David A; Dickman, Mark J; Canniffe, Daniel P; Neil Hunter, C

    2017-11-07

    The X-ray crystal structure of the Rhodopseudomonas (Rps.) palustris reaction center-light harvesting 1 (RC-LH1) core complex revealed the presence of a sixth protein component, variably referred to in the literature as helix W, subunit W or protein W. The position of this protein prevents closure of the LH1 ring, possibly to allow diffusion of ubiquinone/ubiquinol between the RC and the cytochrome bc1 complex in analogous fashion to the well-studied PufX protein from Rhodobacter sphaeroides. The identity and function of helix W have remained unknown for over 13 years; here we use a combination of biochemistry, mass spectrometry, molecular genetics and electron microscopy to identify this protein as RPA4402 in Rps. palustris CGA009. Protein W shares key conserved sequence features with PufX homologs, and although a deletion mutant was able to grow under photosynthetic conditions with no discernible phenotype, we show that a tagged version of protein W pulls down the RC-LH1 complex. Protein W is not encoded in the photosynthesis gene cluster and our data indicate that only approximately 10% of wild-type Rps. palustris core complexes contain this non-essential subunit; functional and evolutionary consequences of this observation are discussed. The ability to purify uniform RC-LH1 and RC-LH1-protein W preparations will also be beneficial for future structural studies of these bacterial core complexes. Copyright © 2017. Published by Elsevier B.V.

  14. Xylanase supplementation to rye diets for growing pigs

    DEFF Research Database (Denmark)

    Nørgaard, Jan Værum; Pedersen, Trine Friis; Blaabjerg, Karoline

    2016-01-01

    Supplementation of xylanase to pig diets can hydrolyze arabinoxylan (AX) into lower molecular weight compounds and thereby decrease the viscosity and improve nutrient utilization. Xylanase supplementation has, however, shown variable effects in diets containing wheat, rye, and combinations thereof...... excretion of N and P did not differ among treatments. Besides a linear effect (P = 0.05) on ATTD of fat, there were neither linear nor quadratic responses to xylanase supplementation on ATTD of OM, starch, NSP, AX, fat, N, and P. In conclusion, supplementation of endo-1,4-β-xylanase did not improve...... the nutritional value of rye in growing pigs....

  15. Two New Flavone Glycosides from Chenopodiumambrosioides Growing Wildly in Egypt

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    Hala M. Hammoda

    2015-06-01

    Full Text Available Chenopodiumambrosioides (Chenopodiaceae growing wildly in Egypt was subjected to antioxidant –guided phytochemical investigation and the EtOAc fraction afforded the two new flavone glycosides; scutellarein-7-O-α-rhamnopyranosyl-(1→2-α-rhamnopyranosyl-(1→2-α-rhamnopyranoside (1 and scutella-rein-7-O-α-rhamnopyranosyl-(1→2-α-rhamnopyranoside (2. In addition, the invitro antioxidant activities of the plant alcohol extract, CHCl 3 fraction, EtOAc fraction and isolates were studied.

  16. How Copper Nanowires Grow and How To Control Their Properties.

    Science.gov (United States)

    Ye, Shengrong; Stewart, Ian E; Chen, Zuofeng; Li, Bo; Rathmell, Aaron R; Wiley, Benjamin J

    2016-03-15

    Scalable, solution-phase nanostructure synthesis has the promise to produce a wide variety of nanomaterials with novel properties at a cost that is low enough for these materials to be used to solve problems. For example, solution-synthesized metal nanowires are now being used to make low cost, flexible transparent electrodes in touch screens, organic light-emitting diodes (OLEDs), and solar cells. There has been a tremendous increase in the number of solution-phase syntheses that enable control over the assembly of atoms into nanowires in the last 15 years, but proposed mechanisms for nanowire formation are usually qualitative, and for many syntheses there is little consensus as to how nanowires form. It is often not clear what species is adding to a nanowire growing in solution or what mechanistic step limits its rate of growth. A deeper understanding of nanowire growth is important for efficiently directing the development of nanowire synthesis toward producing a wide variety of nanostructure morphologies for structure-property studies or producing precisely defined nanostructures for a specific application. This Account reviews our progress over the last five years toward understanding how copper nanowires form in solution, how to direct their growth into nanowires with dimensions ideally suited for use in transparent conducting films, and how to use copper nanowires as a template to grow core-shell nanowires. The key advance enabling a better understanding of copper nanowire growth is the first real-time visualization of nanowire growth in solution, enabling the acquisition of nanowire growth kinetics. By measuring the growth rate of individual nanowires as a function of concentration of the reactants and temperature, we show that a growing copper nanowire can be thought of as a microelectrode that is charged with electrons by hydrazine and grows through the diffusion-limited addition of Cu(OH)2(-). This deeper mechanistic understanding, coupled to an

  17. Designing a Growing Functional Modules “Artificial Brain”

    Directory of Open Access Journals (Sweden)

    Jérôme Leboeuf-Pasquier

    2012-05-01

    Full Text Available

    The present paper illustrates the design process for the Growing Functional Modules (GFM learning based controller. GFM controllers are elaborated interconnecting four kinds of components: Global Goals, Acting Modules, Sensations and Sensing Modules. Global Goals trigger intrinsic motivations, Acting and Sensing Modules develop specific functionalities and Sensations provide the controlled system's feedback. GFM controllers learn to satisfy some predefined goals while interacting with the environment and thus should be considered as artificial brains. An example of the design process of a simple controller is provided herein to explain the inherent methodology, to exhibit the components' interconnections and to demonstrate the control process.

  18. Antioxidant properties of some plants growing wild in Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Serteser, A.; Kargioglu, M.; Gok, V.; Bagci, Y.; Musa Ozcan, M.; Arslan, D.

    2009-07-01

    In this study, the antioxidant activity of 50% aqueous methanol extracts of 38 plants growing in the Afyonkarahisar province of Turkey were evaluated by various antioxidant assay, including free radical scavenging, hydrogen peroxide (H{sub 2}O{sub 2}) scavenging and metal (Fe{sup 2}+) chelating activities. The methanolic fruit extracts of the Cornus and Morus species (H{sub 2}O{sub 2} and DPPH scavenging activities, Fe{sup 2}+ chelating activity) and the methanolic leaf extracts of the Mentha species (DPPH scavenging activities) examined in the assay showed the strongest activities. These antioxidant properties depended on the concentration of samples. (Author) 30 refs.

  19. Humus application produced by organic waste transformation in growing lands

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez Martinez, M. G.; Morales Osorio, A.; Gutierrez Martinez, R.; Marquez Monsalvo, J. J.; Reyes Reyes, G.

    2009-07-01

    Every year in Mexico are produced more tons of garbage (19 874 259 tons) than tons of corn (18 309 000 tons). Fifty percent of domestic garbage is constituted by organic remainders. In december 2005 began de project Biotransformation of Organic Remainders in Humus for its Application in growing Lands with the purpose to prove the methods of: 1) Natural outdoors transformation, 2) Accelerated fermentation with thermophilic and mesophilic microorganisms, and 3) Transformation with microorganisms such as californian red worm, Eisenia andrei, to transform efficiently fruits and vegetables remainders. (Author)

  20. Video Segmentation Using Fast Marching and Region Growing Algorithms

    Directory of Open Access Journals (Sweden)

    Eftychis Sifakis

    2002-04-01

    Full Text Available The algorithm presented in this paper is comprised of three main stages: (1 classification of the image sequence and, in the case of a moving camera, parametric motion estimation, (2 change detection having as reference a fixed frame, an appropriately selected frame or a displaced frame, and (3 object localization using local colour features. The image sequence classification is based on statistical tests on the frame difference. The change detection module uses a two-label fast marching algorithm. Finally, the object localization uses a region growing algorithm based on the colour similarity. Video object segmentation results are shown using the COST 211 data set.

  1. BLOOD METABOLIC HORMONES AND LEPTIN IN GROWING LAMBS

    Directory of Open Access Journals (Sweden)

    Zvonko Antunović

    2010-12-01

    Full Text Available The aim of this paper is to determine the concentration of blood metabolic hormones and leptin levels in growing lambs. The research was carried out on Tsigai lambs in two periods (suckling and fattening during the winter feeding season. Lambs were suckling and ate a food mixture and alfalfa hay ad libitum, while during the fattening period they were fed only with the above mentioned mixture and alfalfa hay ad libitum. Their blood was analyzed on 35th and 75th day of age. Concentrations of minsulin, leptin and thyroid hormones were determined in the blood serum of lambs during both periods. In the blood of fattening lambs significantly higher (P0.05 insulin concentrations (1.05 and 0.54 μU/mL, were determined, compared to suckling lambs. A significant strong positive correlation between serum leptin and insulin (r = 0.85, P0.05. The concentration of thyroid hormones did not significantly differ depending on the period of measurement. These changes indicate that the measurement concentrations of metabolic hormones and leptin in blood are very important in order to understand the changes of metabolism and nutrient supply in growing lambs.

  2. Growing Pains for New Energy-Saving Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, S.

    2004-10-01

    As we contemplate a revolution in the lighting industry, it is yet unclear in what form tomorrow's solid-state lighting will emerge. Similarly, photovoltaic (PV) power supplied on a utility scale may take a different form from today's flat-plate silicon modules. The success of the PV industry-now a multibillion dollar a year industry and growing at more than 25% per year-has largely come from integrating solar cells into other products. In many cases, this integration required the formation of new business entities. The solid-state lighting industry faces hurdles that are similar to those faced by the PV industry. Therefore, based on the experiences of the PV industry and others, we predict that the growing pains of the solid-state lighting industry will include: (1) identifying entry markets, (2) integrating light-emitting diodes into attractive products, (3) attaining high reliability for these products, and (4) increasing production of these products, thus lowering costs and opening up new markets. These activities must be implemented, keeping in mind that most consumers do not care about buying ''solid-state lighting'' and ''solar cells.'' Rather, they want to buy attractive lighting and inexpensive electricity.

  3. Growing patterns to produce 'nitrate-free' lettuce (Lactuca sativa).

    Science.gov (United States)

    Croitoru, Mircea Dumitru; Muntean, Daniela-Lucia; Fülöp, Ibolya; Modroiu, Adriana

    2015-01-01

    Vegetables can contain significant amounts of nitrate and, therefore, may pose health hazards to consumers by exceeding the accepted daily intake for nitrate. Different hydroponic growing patterns were examined in this work in order to obtain 'nitrate-free lettuces'. Growing lettuces on low nitrate content nutrient solution resulted in a significant decrease in lettuces' nitrate concentrations (1741 versus 39 mg kg(-1)), however the beneficial effect was cancelled out by an increase in the ambient temperature. Nitrate replacement with ammonium was associated with an important decrease of the lettuces' nitrate concentration (from 1896 to 14 mg kg(-1)) and survival rate. An economically feasible method to reduce nitrate concentrations was the removal of all inorganic nitrogen from the nutrient solution before the exponential growth phase. This method led to lettuces almost devoid of nitrate (10 mg kg(-1)). The dried mass and calcinated mass of lettuces, used as markers of lettuces' quality, were not influenced by this treatment, but a small reduction (18%, p < 0.05) in the fresh mass was recorded. The concentrations of nitrite in the lettuces and their modifications are also discussed in the paper. It is possible to obtain 'nitrate-free' lettuces in an economically feasible way.

  4. Elder Orphans Hiding in Plain Sight: A Growing Vulnerable Population

    Directory of Open Access Journals (Sweden)

    Maria T. Carney

    2016-01-01

    Full Text Available Adults are increasingly aging alone with multiple chronic diseases and are geographically distant from family or friends. It is challenging for clinicians to identify these individuals, often struggling with managing the growing difficulties and the complexities involved in delivering care to this population. Clinicians often may not recognize or know how to address the needs that these patients have in managing their own health. While many such patients function well at baseline, the slightest insult can initiate a cascade of avoidable negative events. We have resurrected the term elder orphan to describe individuals living alone with little to no support system. Using public data sets, including the US Census and University of Michigan’s Health and Retirement Study, we estimated the prevalence of adults 65 years and older to be around 22%. Thus, in this paper, we strive to describe and quantify this growing vulnerable population and offer practical approaches to identify and develop care plans that are consistent with each person’s goals of care. The complex medical and psychosocial issues for elder orphans significantly impact the individual person, communities, and health-care expenditures. We hope to encourage professionals across disciplines to work cooperatively to screen elders and implement policies to prevent elder orphans from hiding in plain sight.

  5. Projecting Future Change in Growing Degree Days of Winter Wheat

    Science.gov (United States)

    Ruiz Castillo, N.; Gaitan Ospina, C. F.; Mcpherson, R. A.

    2015-12-01

    Southwest Oklahoma is one of the most productive regions in the Great Plains where winter wheat is produced. To assess the effect of climate change on the growing degree days (GDD) available for winter wheat production, we selected from the CMIP5 archive, two of the best performing Global Climate Models (GCMs) for the region (MIROC5 and CCSM4) to project the future change in GDD under the Representative Concentration Pathway (RCP) 8.5 —a "business as usual" future trajectory for greenhouse gas concentrations. Two quantile mapping downscaling methods were applied to both GCMs to obtain local scale projections. The downscaled outputs were applied to a GDD formula to show the GDD changes between the historical period (1961-2004) and the future period (2006-2098) in terms of mean differences. The results show that at the end of the 2098 growing season, the increase in GDD is expected to be between -2.0 and 6. Depending on the GCM used, Southwest Oklahoma is expected to see an increase in future GDD under the CCSM4 GCM and a mix of increase, no change and decrease under the MIROC5 GCM.

  6. A dynamic cellular vertex model of growing epithelial tissues

    Science.gov (United States)

    Lin, Shao-Zhen; Li, Bo; Feng, Xi-Qiao

    2017-04-01

    Intercellular interactions play a significant role in a wide range of biological functions and processes at both the cellular and tissue scales, for example, embryogenesis, organogenesis, and cancer invasion. In this paper, a dynamic cellular vertex model is presented to study the morphomechanics of a growing epithelial monolayer. The regulating role of stresses in soft tissue growth is revealed. It is found that the cells originating from the same parent cell in the monolayer can orchestrate into clustering patterns as the tissue grows. Collective cell migration exhibits a feature of spatial correlation across multiple cells. Dynamic intercellular interactions can engender a variety of distinct tissue behaviors in a social context. Uniform cell proliferation may render high and heterogeneous residual compressive stresses, while stress-regulated proliferation can effectively release the stresses, reducing the stress heterogeneity in the tissue. The results highlight the critical role of mechanical factors in the growth and morphogenesis of epithelial tissues and help understand the development and invasion of epithelial tumors.

  7. Force-velocity measurements of a few growing actin filaments.

    Directory of Open Access Journals (Sweden)

    Coraline Brangbour

    2011-04-01

    Full Text Available The polymerization of actin in filaments generates forces that play a pivotal role in many cellular processes. We introduce a novel technique to determine the force-velocity relation when a few independent anchored filaments grow between magnetic colloidal particles. When a magnetic field is applied, the colloidal particles assemble into chains under controlled loading or spacing. As the filaments elongate, the beads separate, allowing the force-velocity curve to be precisely measured. In the widely accepted Brownian ratchet model, the transduced force is associated with the slowing down of the on-rate polymerization. Unexpectedly, in our experiments, filaments are shown to grow at the same rate as when they are free in solution. However, as they elongate, filaments are more confined in the interspace between beads. Higher repulsive forces result from this higher confinement, which is associated with a lower entropy. In this mechanism, the production of force is not controlled by the polymerization rate, but is a consequence of the restriction of filaments' orientational fluctuations at their attachment point.

  8. Perspective on how laser-ablated particles grow in liquids

    Science.gov (United States)

    Zhang, DongShi; Liu, Jun; Liang, ChangHao

    2017-07-01

    Laser ablation in liquids has emerged as a new branch of nanoscience for developing various nanomaterials with different shapes. However, how to design and control nanomaterial growth is still a challenge due to the unique chemical-physical process chain correlated with nanomaterial nucleation and growth, including plasma phase (generation and rapid quenching), gas (bubble) phase, and liquid phase. In this review, through summarizing the literature about this topic and comparing with the well-established particle growth mechanisms of the conventional wet chemistry technique, our perspective on the possible nanoparticle growth mechanisms or routes is presented, aiming at shedding light on how laser-ablated particles grow in liquids. From the microscopic viewpoint, the nanoparticle growth contains six mechanisms, including LaMer-like growth, coalescence, Ostwald ripening, particle (oriented) attachment, adsorbate-induced growth and reaction-induced growth. For each microscopic growth mechanism, the vivid growth scenes of some representative nanomaterials recorded by TEM and SEM measurements are displayed. Afterwards, the scenes from the macroscopic viewpoint for the large submicro- and micro-scale nanospheres and anisotropic nanostructures formation and evolution from one nanostructure into another one are presented. The panorama of how diverse nanomaterials grow during and after laser ablation in liquids shown in this review is intended to offer a overview for researchers to search for the possible mechanisms correlated to their synthesized nanomaterials, and more expectation is desired to better design and tailor the morphology of the nanocrystals synthesized by LAL technique.

  9. Biomass accumulation in rapidly growing loblolly pine and sweetgum

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Thomas M.; Gresham, Charles A. [Baruch Institute of Coastal Ecology and Forest Science, Clemson University, P.O. Box 596, Georgetown, SC 29442 (United States)

    2006-04-15

    Loblolly pine (Pinus taeda) and sweetgum (Liquidambar styraciflua) trees, growing in International Paper Company's study of intensive management on marginal agricultural land near Bainbridge GA, were destructively sampled at the end of the sixth growing season. All trees were single family blocks of genetically superior trees planted 2.5m apart on sub-soiled rows 3.6m apart and grown with complete competition control. Management treatments were: control, irrigation, irrigation plus fertilization, and irrigation plus fertilization plus pest control. Tree measures were basal diameter, DBH, height of live crown, diameter at base of live crown, and total height. Twenty trees of each species were destructively sampled. Stems were sectioned at 1m intervals, stem diameter determined at each end and sections were weighed green. Branches were removed and height, basal diameter, and length were measured on each branch. Branches were separated into foliated and unfoliated segments and weighed green. A stem disk and branch from each meter were returned to the lab to determine dry weight: green weight ratio. Foliated limb: foliage ratios were also determined from sub-sampled branches. Intensive culture resulted in larger growth differences for sweetgum (most intensive treatment 9.5m tall, 13.1cm DBH; control trees 5.0m tall, 6.3cm DBH) than in pine (most intensive treatment 10.3m tall, 17.7cm DBH; control, 7.6m tall, 13.4cm DBH). The pipe model of tree development explained dimensions of the upper 5m of crown with leaf biomass highly correlated to branch basal area (r{sup 2} from 0.697 to 0.947). There was a constant ratio of leaf biomass to branch basal area (50gm/cm{sup 2} for pine, 30gm/cm{sup 2} for sweetgum). We also found a constant ratio of bole basal area to cumulative branch basal area throughout the crowns. Rapidly growing pines produced about 49Mgha{sup -1} of stem biomass, 11Mgha{sup -1} of dead branch biomass, and 17Mgha{sup -1} of unfoliated branch biomass at

  10. Valine needs in starting and growing Cobb (500) broilers.

    Science.gov (United States)

    Tavernari, F C; Lelis, G R; Vieira, R A; Rostagno, H S; Albino, L F T; Oliveira Neto, A R

    2013-01-01

    Two independent experiments were conducted with male Cobb × Cobb 500 broilers to determine the optimal valine-to-digestible-lysine ratio for broiler development. We conducted a randomized block experiment with 7 treatments, each with 8 replicates of 25 starter birds (8 to 21 d of age) and 20 finisher (30 to 43 d of age) birds. To prevent any excess of digestible lysine, 93% of the recommended level of digestible lysine was used to evaluate the valine-to-lysine ratio. The utilized levels of dietary digestible lysine were 10.7 and 9.40 g/kg for the starting and growing phases, respectively. A control diet with 100% of the recommended level of lysine and an adequate valine-to-lysine ratio was also used. The feed intake, weight gain, feed conversion ratio, and carcass parameters were evaluated. The treatments had no significant effect on the feed intakes or carcass parameters in the starter and finisher phases. However, during both of the studied phases, we observed a quadratic effect on weight gain and the feed conversion ratio. The broilers of both phases that were fed test diets with the lower valine-to-lysine (Val/Lys) ratio had poorer performance compared with those broilers fed control diets. However, when higher Val/Lys ratios were used for the starting and growing broilers that were fed test diets, the 2 groups had similar performance. During the starting phase, in broilers that were fed a higher Val/Lys ratio, weight gain, and the feed conversion ratio improved by 5.5% compared with broilers fed the basal diets. The broilers in the growing phase also had improved performance (by 7 to 8%) when the test diets had higher Val/Lys ratios. Based on the analysis of the starter phase data, we concluded that the optimal digestible Val/Lys ratio for Cobb × Cobb 500 broilers is 77%, whereas for birds in the finisher phase (30 to 43 d of age), a digestible Val/Lys ratio of 76% is suggested.

  11. Fruit-Growing in Latvia – Industry and Science

    Directory of Open Access Journals (Sweden)

    Kaufmane Edīte

    2017-06-01

    Full Text Available In all times, fruit trees for family use have been grown at Latvian farms. Yet these fruits obtained market value only after the land ownership reform in 19th century. This facilitated rapid area increase of different fruit crops, allowing supply with fruits not only the local market, but also for export to the largest cities of Russia. Especially fast development of fruit-growing was observed during the first independent republic (1919–1940. The demand for planting material increased, and plants were imported from Western Europe. Choice of unsuitable cultivars and rootstocks was the main reason of the massive orchard area loss during the following severe winters. After the Second World War, the Soviet powers supported only the establishment of large orchards for processing needs, 200-300 ha, which were unsuitable for the Latvian climate and terrain. At the same time, numbers of allotment gardens rapidly increased and part of their produce was sold also on the market. After regaining of independence and private property, interest in fresh fruit and berry production for market, as well as processing, renewed. It was hindered by lack of continuity in experience and knowledge. Diversity of terrain, soils and climate all demand considerate choice of suitable orchard location and cultivars. Direct use of foreign experience often led to failure. At present, development of the fruit industry is most of all hindered by lack of qualified specialists of different levels, which does not allow to establish an appropriate consulting system. Cooperation of growers for easier marketing also is developing too slowly. Insufficient economic and market research does not allow to balance the demand with increase of plantation area, especially for large-scale processing and export, so strategic guidance of the fruit industry is not possible. Development of fruit-growing is hindered also by a lack of continuous long-term support to horticultural science. As a

  12. Dynamical analysis of Schrodinger operators with growing sparse potentials

    CERN Document Server

    Tcheremchantsev, S

    2003-01-01

    We consider Scr\\"odinger operators in l^2(Z^+) with potentials of the form V(n)=S(n)+Q(n). Here S is a sparse potential: S(n)=n^{1-\\eta \\over 2 \\eta}, 0<\\eta <1, for n=L_N and S(n)=0 else, where L_N is a very fast growing sequence. The real function Q(n) is compactly supported. We give a rather complete description of the (time-averaged) dynamics exp(-itH) \\psi for different initial states \\psi. In particular, for some \\psi we calculate explicitely the "intermittency function" \\beta_\\psi^- (p) which turns out to be nonconstant. As a particular corollary of obtained results, we show that the spectral measure restricted to (-2,2) has exact Hausdorff dimension \\eta for all boundary conditions, improving the result of Jitomirskaya and Last.

  13. Ranking nodes in growing networks: When PageRank fails.

    Science.gov (United States)

    Mariani, Manuel Sebastian; Medo, Matúš; Zhang, Yi-Cheng

    2015-11-10

    PageRank is arguably the most popular ranking algorithm which is being applied in real systems ranging from information to biological and infrastructure networks. Despite its outstanding popularity and broad use in different areas of science, the relation between the algorithm's efficacy and properties of the network on which it acts has not yet been fully understood. We study here PageRank's performance on a network model supported by real data, and show that realistic temporal effects make PageRank fail in individuating the most valuable nodes for a broad range of model parameters. Results on real data are in qualitative agreement with our model-based findings. This failure of PageRank reveals that the static approach to information filtering is inappropriate for a broad class of growing systems, and suggest that time-dependent algorithms that are based on the temporal linking patterns of these systems are needed to better rank the nodes.

  14. Ranking nodes in growing networks: When PageRank fails

    Science.gov (United States)

    Mariani, Manuel Sebastian; Medo, Matúš; Zhang, Yi-Cheng

    2015-11-01

    PageRank is arguably the most popular ranking algorithm which is being applied in real systems ranging from information to biological and infrastructure networks. Despite its outstanding popularity and broad use in different areas of science, the relation between the algorithm’s efficacy and properties of the network on which it acts has not yet been fully understood. We study here PageRank’s performance on a network model supported by real data, and show that realistic temporal effects make PageRank fail in individuating the most valuable nodes for a broad range of model parameters. Results on real data are in qualitative agreement with our model-based findings. This failure of PageRank reveals that the static approach to information filtering is inappropriate for a broad class of growing systems, and suggest that time-dependent algorithms that are based on the temporal linking patterns of these systems are needed to better rank the nodes.

  15. The Leaf Essential Oil of Eugenia reinwardtiana Growing in Australia.

    Science.gov (United States)

    Brophy, Joseph J; Clarkson, John R; Deseo, Myrna A; Ford, Andrew J; Lawes, Douglas J; Leach, David N

    2015-09-01

    The leaf essential oils of the two chemotypes of Eugenia reinwardtiana (Blume) DC growing in Australia have been investigated. Chemotype 1, isolated in 0.2% yield, w/w, dry weight, contained major amounts of α-pinene (10-26%), limonene (1-15%), β-caryophyllene (0.7-11%), α-humulene (0.9-16%) and bicyclogermacrene (1-23%). The second chemotype, found only on coastal dunes SW of Lockerbie Qld, and isolated in 0.4-0.6% (w/w, dry weight), contained α-pinene (tr-8.5%) β-caryophyllene (12-27%) and α-humulene (1-17%) as the major terpenes. This chemotype also contained the novel aliphatic diketone, 2-butyl-2,4,4-trimethyl-5-methoxycyclohex-5-en-1,3-dione (18-33%), whose structure determination is reported herein.

  16. Cleaner Production: A Growing Movement in Brazilian Companies

    Directory of Open Access Journals (Sweden)

    Oduvaldo Vendrametto

    2010-03-01

    Full Text Available Cleaner Production (CP is gaining emphasis in both world and Brazilian production sectors. Nature’s warnings indicating the exhaustion of any capacity to absorb and regenerate waste, stricter legislation regarding pollution emitters, market competitiveness associated with environmental and social responsibility cause concerns and lead to actions to reduce aggressions against the environment. This paper shows evidence of this concern and presents cases in which a large automotive industry, acting as a partner to suppliers, promotes changes in how it delivers its products, eliminating large cardboard, plastic and wood packaging. A small company had a similar initiative, reducing the use of cardboard and plastic packaging. More important is the revelation of a widely dispersed, yet growing and incremental movement of responsibilities among companies.The benefits of cleaner production implementation were evaluated by confronting environmental and financial assessment. For the ambient evaluation, it will be used methodology of Material Intensity (Wuppertal Institute, a.

  17. Actin filaments growing against a barrier with fluctuating shape.

    Science.gov (United States)

    Sadhu, Raj Kumar; Chatterjee, Sakuntala

    2016-06-01

    We study force generation by a set of parallel actin filaments growing against a nonrigid obstacle, in the presence of an external load. The filaments polymerize by either moving the whole obstacle, with a large energy cost, or by causing local distortion in its shape which costs much less energy. The nonrigid obstacle also has local thermal fluctuations due to which its shape can change with time and we describe this using fluctuations in the height profile of a one-dimensional interface with Kardar-Parisi-Zhang dynamics. We find the shape fluctuations of the barrier strongly affect the force generation mechanism. The qualitative nature of the force-velocity curve is crucially determined by the relative time scale of filament and barrier dynamics. The height profile of the barrier also shows interesting variation with the external load. Our analytical calculations within mean-field theory show reasonable agreement with our simulation results.

  18. Elastic instability of a crystal growing on a curved surface.

    Science.gov (United States)

    Meng, Guangnan; Paulose, Jayson; Nelson, David R; Manoharan, Vinothan N

    2014-02-07

    Although the effects of kinetics on crystal growth are well understood, the role of substrate curvature is not yet established. We studied rigid, two-dimensional colloidal crystals growing on spherical droplets to understand how the elastic stress induced by Gaussian curvature affects the growth pathway. In contrast to crystals grown on flat surfaces or compliant crystals on droplets, these crystals formed branched, ribbon-like domains with large voids and no topological defects. We show that this morphology minimizes the curvature-induced elastic energy. Our results illustrate the effects of curvature on the ubiquitous process of crystallization, with practical implications for nanoscale disorder-order transitions on curved manifolds, including the assembly of viral capsids, phase separation on vesicles, and crystallization of tetrahedra in three dimensions.

  19. Analysis Regarding the Growing Presence of Italian Firms in Romania

    Directory of Open Access Journals (Sweden)

    Stefano Valdemarin

    2015-12-01

    Full Text Available At the end of 2014, the number of firms with an Italian presence in Romania was 39,556, representing 19.33% out of total registered firms and this number is still growing. This article focuses on answering the following question: what kind of Italian firms are investing in Romania and why? Starting from the empirical observation that the number of Italian firms in Romania grew by 6.82% last year, we have used a PESTEL analysis to find the key points characterizing the country, paying attention also to the concept of country brand. From the point of view of Italian firms, we have also analyzed the shifting paradigm of internationalization from a Vertical Foreign Direct Investment model to a Horizontal Foreign Direct Investment model. This paper can be useful for managers and entrepreneurs who are oriented towards investing in Romania following the path of Italian firms.

  20. Capital income taxation in a growing open economy

    DEFF Research Database (Denmark)

    Nielsen, Søren Bo; Sørensen, Peter Birch

    1991-01-01

    of a (low) corporate income tax will not affect consumption in the long run, but will simply lead to a replacement of shares by foreign financial assets in household portfolios. It is also found that an anticipated investment tax credit can have and that an anticipated dividend tax will have contractionary...... effects on investment before they are introduced. Moreover, it is shown that while an unanticipated dividend tax is neutral with respect to investment, it will have real effects on consumption and net foreign assets in a growing economy......The paper studies the dynamic macroeconomic effects of various forms of capital income taxation in a model of a small open economy with perfect mobility of financial capital and intertemporal optimization on the part of households and firms. One of the noteworthy results is that the introduction...

  1. Passive random walkers and riverlike networks on growing surfaces.

    Science.gov (United States)

    Chin, Chen-Shan

    2002-08-01

    Passive random walker dynamics is introduced on a growing surface. The walker is designed to drift upward or downward and then follow specific topological features, such as hill tops or valley bottoms, of the fluctuating surface. The passive random walker can thus be used to directly explore scaling properties of otherwise somewhat hidden topological features. For example, the walker allows us to directly measure the dynamical exponent of the underlying growth dynamics. We use the Kardar-Parisi-Zhang (KPZ) -type surface growth as an example. The world lines of a set of merging passive walkers show nontrivial coalescence behaviors and display the riverlike network structures of surface ridges in space-time. In other dynamics, such as Edwards-Wilkinson growth, this does not happen. The passive random walkers in KPZ-type surface growth are closely related to the shock waves in the noiseless Burgers equation. We also briefly discuss their relations to the passive scalar dynamics in turbulence.

  2. Acacia mangium: Growing and utilization. MPTS monograph series No. 3

    Energy Technology Data Exchange (ETDEWEB)

    Awang, K.; Taylor, D.

    1993-01-01

    With deforestation in the Asia-Pacific region progressing at the rate of 4.4 million ha per year, many countries have adopted plantation forestry using fast-growing species as a way to sustain the commercial supply of tree products and reduce pressure on natural forests. Acacia mangium (A. mangium) is playing a large role in this development, especially in Indonesia and Malaysia, due to its versatility and its ability to recapture grasslands dominated by the noxious weed, Imperata cylindrica. This monograph consolidates information on A. mangium from published literature, unpublished reports and studies, and observations from those familiar with the species. Priorities for future research are included in each chapter and in the final summary.

  3. Mushroom growing project at the Los Humeros, Mexico geothermal field

    Energy Technology Data Exchange (ETDEWEB)

    Rangel, M.E.R. [Comision Federal de Electricidad (Mexico)

    1998-12-01

    There are several projects of direct (non-electrical) use of geothermal energy in Mexico. Personnel of the Comision Federal de Electricidad (CFE) have experience in various of these projects, like drying of timber and fruits, space heating, food processing, etc. Taking this in consideration, CFE built the Los Humeros mushroom plant using for heat source the geothermal steam from Well H-1. The main purpose of the project was to take advantage of residual geothermal energy in a food production operation and to develop the appropriate technology. In 1992, existing installations were renovated, preparing appropriate areas for pasteurization, inoculation and production. The mushroom Pleurotus ostreatus var. florida and columbinus was used. A year later, CFE proposed the construction of improved facilities for growing edible mushrooms. New materials and equipment, as well as different operation conditions, were proposed on the basis of the experience gained in the initial project. The construction and renovation activities were completed in 1994.

  4. A conceptual model for growing evidence-based practice.

    Science.gov (United States)

    Vratny, Amy; Shriver, Deb

    2007-01-01

    Nursing administration at a small medical center is developing and implementing an evidence-based practice (EBP) model of care to support a culture of quality care, clinical excellence, cost-effectiveness, critical thinking, empowerment of staff, and professional growth. The purpose of this article is to describe a conceptual model for EBP that addresses how to overcome barriers to implementation. Clinician expertise and values, experience, patient preference and expectation, and caring become grounded in a practice environment that must strive to become rooted in clinical research to evolve into a practice that is evidence-based. Education helps to nourish EBP, but leadership, enthusiasm, mentorship, clinical inquiry, and reflective practice make EBP thrive. The EBP ambassadors branch out to each department to grow journal clubs, EBP Web pages, EBP projects, research utilization projects, and staff-led practice reviews. The fruits are quality patient care and outcomes, clinical excellence, cost-effectiveness, critical thinking, empowerment of staff, and professional growth.

  5. Exploitation Strategies in Social Parasites of Fungus Growing Ants

    DEFF Research Database (Denmark)

    Clement, Janni Dolby

    One of the most remarkable and complex parasitic interactions is social parasitism, where a parasite exploits a complete society, rather than an individual organism. By integrating into a society the parasite gains protection against predators and diseases, and can redirect resources from the host...... to increase its own fitness. The host will use a sophisticated recognition system in order to accept nestmates and expel intruders from their societies. However this defence barrier can be overcome by parasites. Among the most specialized social parasites are the inquilines that exploit social insect colonies...... to this are Acromyrmex insinuator and Acromyrmex ameliae, parasites of fungus-growing ants. By still producing a worker caste both species offers a rare opportunity to study adaptive features in parasite worker behaviour. Furthermore can closely related inquiline-host combinations give us an insight in the trade...

  6. A growing social network model in geographical space

    Science.gov (United States)

    Antonioni, Alberto; Tomassini, Marco

    2017-09-01

    In this work we propose a new model for the generation of social networks that includes their often ignored spatial aspects. The model is a growing one and links are created either taking space into account, or disregarding space and only considering the degree of target nodes. These two effects can be mixed linearly in arbitrary proportions through a parameter. We numerically show that for a given range of the combination parameter, and for given mean degree, the generated network class shares many important statistical features with those observed in actual social networks, including the spatial dependence of connections. Moreover, we show that the model provides a good qualitative fit to some measured social networks.

  7. I don't want to grow old

    DEFF Research Database (Denmark)

    Selberg, Hanne; Sharp-Johansen, Marie-Louise; Evron, Lotte

    2015-01-01

    the inconveniences of mus-culoskeletal, visual and auditory changes. Five two-hours' workshops were conducted with 60 students in total. The workshops consisted of an initial briefing, scenario performance, debriefing and final evaluation. (Preliminary) Results Themes from analysis: - Concerns of growing old...... - Bodily experiences of movement reduction and in the different senses - Simulation as an eye-opener to new understandings of old age - Cognitive and bodily experiences of the time perspective - Bodily-kinesthetic learning Conclusions Our results indicate that old age simulation enhanced learning...... as a result of combined physical and cognitive activities receiving information from all the senses and emotional involvement. The study suggests bodily ac-tivity in simulation enhance learning....

  8. Intraoral tumor with rapid growing. Report of a case.

    Science.gov (United States)

    González-Martín-Moro, Javier; Cebrián-Carretero, Jose Luis; Gómez-García, Elena; del Castillo-Pardo de Vera, Jose Luis; del Val, Daniel

    2005-01-01

    The appearance of an intraoral mass is common in our specialty. Most are benign lesions, but some are primary malignancies. Metastases account for less than 1% of all oral malignancies. An 86 year old woman was referred to our department with a large, asymptomatic, intraoral, fast-growing mass. She had no previous cancer history or other relevant physical findings. The radiology studies showed underlying bone erosion. The histological study showed a metastatic adenocarcinoma with a suspected origin in the abdomen. We were unable to identify it by non invasive diagnostic procedures. Given the patient's general status and despite the ominous prognosis of such lesions, we decided not to perform any aggressive therapy beyond removing the oral mass, in order to maintain her quality of life. There have been no local recurrences until this time.

  9. Garden sharing and garden stealing in fungus-growing ants

    Science.gov (United States)

    Adams, Rachelle M. M.; Mueller, U. G.; Holloway, Alisha K.; Green, Abigail M.; Narozniak, Joanie

    Fungi cultivated by fungus-growing ants (Attini: Formicidae) are passed on between generations by transfer from maternal to offspring nest (vertical transmission within ant species). However, recent phylogenetic analyses revealed that cultivars are occasionally also transferred between attine species. The reasons for such lateral cultivar transfers are unknown. To investigate whether garden loss may induce ants to obtain a replacement cultivar from a neighboring colony (lateral cultivar transfer), pairs of queenright colonies of two Cyphomyrmex species were set up in two conjoined chambers; the garden of one colony was then removed to simulate the total crop loss that occurs naturally when pathogens devastate gardens. Garden-deprived colonies regained cultivars through one of three mechanisms: joining of a neighboring colony and cooperation in a common garden; stealing of a neighbor's garden; or aggressive usurpation of a neighbor's garden. Because pathogens frequently devastate attine gardens under natural conditions, garden joining, stealing and usurpation emerge as critical behavioral adaptations to survive garden catastrophes.

  10. "Something good can grow here": chicago urban agriculture food projects.

    Science.gov (United States)

    Hatchett, Lena; Brown, Loretta; Hopkins, Joan; Larsen, Kelly; Fournier, Eliza

    2015-01-01

    Food security is a challenge facing many African-American low-income communities nationally. Community and university partners have established urban agriculture programs to improve access to high quality affordable fruits and vegetables by growing, distributing, and selling food in urban neighborhoods. While the challenge of food security is within communities of color, few studies have described these urban agriculture programs and documented their impact on the crew members who work in the programs and live in the low-income communities. More information is needed on the program impact for crew and community health promotion. Using a survey and focus group discussion from the crew and staff we describe the program and activities of four Chicago Urban Agriculture programs. We summarized the impact these programs have on crew members' perception of urban agriculture, health habits, community engagement, and community health promotion in low-income African-American neighborhoods.

  11. Influence of growing and exploatation of bovins on regional agroecosystems

    Directory of Open Access Journals (Sweden)

    Cornel Podar

    2011-12-01

    Full Text Available Scientists all over the are concerned regarding the influence of growing ruminants on regional agro-ecosystems due to green house gases resulted (CO 2, CH4, N2O5. Cattle have contributed to environmental pollution in old industrial farming systems, when the cattle number in Romania, reached 8 million, manure evacuation was not solved and manure was accumulating around the farm polluting the soil, water and air. Low density of ruminants existing in the agricultural sector of the country is not significant in terms of pollution. Currently cattle have positive effects on the environment by the use of legumes, grasses and manure production contributing to the increase of agricultural production: crop production (sugar beet, potato and cereals, animal production (milk, meat, leather production and industrial production also (biogas, befouls, alcohol, oil production.

  12. Russian gas exports have potential to grow through 2020

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, Rafael [Instituto Complutense de Estudios Internacionales (ICEI), Faculty of Economics, Department of Applied Economics I, Complutense University, 28223 Pozuelo de Alarcon, Madrid (Spain)

    2009-10-15

    This paper analyzes the potential for Russian gas export growth through the next decade and concludes that supply for exports will continue to grow, albeit moderately. The greater or lesser intensity of that growth will depend on the evolution of both production and internal consumption. From the production side, the pace of growth depends on the status of gas reserves and, more importantly, on the investment program pursued by the State-owned gas giant Gazprom. From the demand side, evolution depends on the way Russia's wide potential for gas savings is managed. Through this analysis, we find three likely scenarios for Russian gas exports. In the most positive, diversification of exports will be possible. In the most negative, Russia will have scant opportunity to develop an export diversification strategy. (author)

  13. Yarn image segmentation using the region growing algorithm

    Science.gov (United States)

    Fabijańska, Anna

    2011-11-01

    This paper is about the development of the image segmentation algorithm for the industrial measurement system. Specifically, the problem of segmentation of textile yarn images is considered. The algorithm developed for yarn hairiness analyzer is introduced. It aims at extracting single fibers protruding from the yarn core. The algorithm is a region growing-based approach where the growth of the region is guided and constrained by the coherence enhancing diffusion filter. Results of the proposed method are presented and compared with the results provided by the traditional clustering approaches and recent, well-established segmentation methods. The comparison proves that the proposed segmentation algorithm provides high quality results and significantly outperforms other methods in number of fibers extracted from the background.

  14. Growing a photonics program in good times and bad

    Science.gov (United States)

    Donnelly, Judith; Seebeck, Randall

    2003-10-01

    Three Rivers Community College (TRCC) is a public, associate degree-granting college located in southeastern Connecticut.. Formed in 1992 by the merger of Thames Valley State Technical College and Mohegan Community College, TRCC is a comprehensive multi-campus college with a full range of programs in technology and engineering technology. Although Connecticut is located in what has been called "Photonics Valley", stretching from Virginia to Massachusetts, eastern Connecticut has few optics related companies and is mainly known for two large Indian gaming casinos and the submarines built at General Dynamics Electric Boat Division in Groton. Yet TRCC has created a two-year associate degree program in Photonics Engineering Technology which continues to grow. This paper describes the development of a photonics technician program at a distance (in Connecticut terms) from supporting industries and explains strategies used to keep the program current with industry and student expectations.

  15. Does a Growing Static Length Scale Control the Glass Transition?

    Science.gov (United States)

    Wyart, Matthieu; Cates, Michael E.

    2017-11-01

    Several theories of the glass transition propose that the structural relaxation time τα is controlled by a growing static length scale ξ that is determined by the free energy landscape but not by the local dynamic rules governing its exploration. We argue, based on recent simulations using particle-radius-swap dynamics, that only a modest factor in the increase in τα on approach to the glass transition may stem from the growth of a static length, with a vastly larger contribution attributable, instead, to a slowdown of local dynamics. This reinforces arguments that we base on the observed strong coupling of particle diffusion and density fluctuations in real glasses.

  16. ENVIRONMENTAL AND SOCIO-ECONOMIC ASPECT OF GROWING MISCANTHUS GENOTYPES

    Directory of Open Access Journals (Sweden)

    Marián KOTRLA

    2013-01-01

    Full Text Available Deliberate cultivation of plants for energy biomass is becoming increasingly important. Biomass should significantly contribute to increase the share of renewable energy in the European Union. On the research locality of Slovak University of Agriculture in Nitra localized in the village Kolíňany (Slovak Republic is implemented basic research focused on the growth and production of the two genotypes energy grass Miscanthus. Research is carried out since 2010. In the third year after planting (the year 2012 were confirmed biomass production depending on the genotype of 35.45 and 36.67 t ha-1. Based on the analysis of growth and production performance of Miscanthus genotypes can be evaluated the high environmental and socio-economic aspects of growing energy crops, depending on the specific agro-ecological conditions.

  17. Infrared allows a peek inside to detect grow-ops

    Energy Technology Data Exchange (ETDEWEB)

    Jastrow, B. [Infrared Solutions, Inc., Minneapolis, MN (United States)

    2009-06-15

    Apartment buildings have become a preferred location for marijuana growers in the Greater Toronto Area. The grow operations pose a fire and health risk to neighbours who may breathe in potentially harmful mould spores and pores from fertilizers. One advantage for growers is that many apartment buildings have only a single hydro meter for the entire building. As such, Toronto Hydro cannot detect extraordinary electricity consumption. This article described a method for detecting high electricity use by infrared thermography. An average size hallway electrical distribution panel is equipped with an 80 Amp or 100 Amp double-pole circuit breaker. Growers unplug the 220 Volt stove outlet and run their 1000 Watt lighting systems for long periods of time. Since the lights create excessive lamp loading, a thermal anomaly can be detected on the individual circuit breaker. High-end thermal imagers will detect this thermal pattern and transpose it into a thermograph. 1 fig.

  18. Antigovernment Groups. A Growing Threat to US Security

    Energy Technology Data Exchange (ETDEWEB)

    Swift, Alicia L. [Los Alamos National Laboratory

    2016-04-25

    Domestic terrorism is a growing threat in the United States, particularly from the 998 right-wing antigovernment (AG) groups in existence in 2015. In the years since the September 11, 2001 attacks in New York City, right-wing anti-government acts have oc- curred more often and killed more people in the United States than Muslim extremists. Such AG group members are often in uenced by racist, anti-Semitic, or anti-Islamic views, believe conspiracy theories about the government, and often refuse to pay taxes or participate in frivolous lawsuits in order to intentionally waste the government's time. There is, however, a violent element to these groups which participates in events ranging from the armed take-over of federal land in Oregon, to an armed stand-o with federal agents in Nevada, to the bombing of the Oklahoma City building which killed 168 people. Such acts may be conducted by a few individuals, as is the case of the Oklahoma City bombing, or an entire group. Such groups have a wide range of capabilities, with typical weapons including legal and illegal rearms, with a focus on purchasing fully automatic weapons; hand grenades, with some homemade; deadly tox- ins, like ricin (in multiple cases) and sodium cyanide (in one case); transportation, such as all-terrain vehicles (ATVs); arson, with the intent of destroying federal property; and explosives, often in large numbers and including pipe bombs, truck bombs, IEDs, and other homemade explosives. The growing acceptance of these violent methods by Republican congressmen and governors, however, only increases visibility of such groups and encourages their behavior. Coupled with the removal of the Department of Homeland Security's division responsible for monitoring such groups, the result could prove disastrous for the safety of United States citizens.

  19. SWIMMING ENHANCES BONE MASS ACQUISITION IN GROWING FEMALE RATS

    Directory of Open Access Journals (Sweden)

    Joanne McVeigh

    2010-12-01

    Full Text Available Growing bones are most responsive to mechanical loading. We investigated bone mass acquisition patterns following a swimming or running exercise intervention of equal duration, in growing rats. We compared changes in bone mineral properties in female Sprague Dawley rats that were divided into three groups: sedentary controls (n = 10, runners (n = 8 and swimmers (n = 11. Runners and swimmers underwent a six week intervention, exercising five days per week, 30min per day. Running rats ran on an inclined treadmill at 0.33 m.s-1, while swimming rats swam in 25oC water. Dual energy X-ray absorptiometry scans measuring bone mineral content (BMC, bone mineral density (BMD and bone area at the femur, lumbar spine and whole body were recorded for all rats before and after the six week intervention. Bone and serum calcium and plasma parathyroid hormone (PTH concentrations were measured at the end of the 6 weeks. Swimming rats had greater BMC and bone area changes at the femur and lumbar spine (p < 0.05 than the running rats and a greater whole body BMC and bone area to that of control rats (p < 0.05. There were no differences in bone gain between running and sedentary control rats. There was no significant difference in serum or bone calcium or PTH concentrations between the groups of rats. A swimming intervention is able to produce greater beneficial effects on the rat skeleton than no exercise at all, suggesting that the strains associated with swimming may engender a unique mechanical load on the bone

  20. On the mechanics of growing thin biological membranes

    Science.gov (United States)

    Rausch, Manuel K.; Kuhl, Ellen

    2014-02-01

    Despite their seemingly delicate appearance, thin biological membranes fulfill various crucial roles in the human body and can sustain substantial mechanical loads. Unlike engineering structures, biological membranes are able to grow and adapt to changes in their mechanical environment. Finite element modeling of biological growth holds the potential to better understand the interplay of membrane form and function and to reliably predict the effects of disease or medical intervention. However, standard continuum elements typically fail to represent thin biological membranes efficiently, accurately, and robustly. Moreover, continuum models are typically cumbersome to generate from surface-based medical imaging data. Here we propose a computational model for finite membrane growth using a classical midsurface representation compatible with standard shell elements. By assuming elastic incompressibility and membrane-only growth, the model a priori satisfies the zero-normal stress condition. To demonstrate its modular nature, we implement the membrane growth model into the general-purpose non-linear finite element package Abaqus/Standard using the concept of user subroutines. To probe efficiently and robustness, we simulate selected benchmark examples of growing biological membranes under different loading conditions. To demonstrate the clinical potential, we simulate the functional adaptation of a heart valve leaflet in ischemic cardiomyopathy. We believe that our novel approach will be widely applicable to simulate the adaptive chronic growth of thin biological structures including skin membranes, mucous membranes, fetal membranes, tympanic membranes, corneoscleral membranes, and heart valve membranes. Ultimately, our model can be used to identify diseased states, predict disease evolution, and guide the design of interventional or pharmaceutic therapies to arrest or revert disease progression.

  1. [Double mulching application for Panax notoginseng growing seedlings].

    Science.gov (United States)

    Ou, Xiao-Hong; Fang, Yan; Shi, Ya-Na; Guo, Lan-Ping; Wang, Li; Yang, Yan; Jin, Hang; Liu, Da-Hui

    2014-02-01

    In order to improve the irrigation for Panax notginseng growing seedlings, different mulching ways were carried out to investigate the effects of double mulching. Field experiment was applied to study soil moisture, soil temperature and bulk density of different mulching ways while the germination rate and seedlings growth also were investigated. Compared with the traditional single mulching with pine leaves or straw, double mulching using plastic film combined with pine leaves or straw could reduce 2/3 volumes of irrigation at the early seedling time Double mulching treatments didn't need to irrigate for 40 days from seeding to germination, and kept soil moisture and temperature steady at whole seedling time about 30% and 9.0-16.6 degrees C, respectively. The steady soil moisture and temperature benefited to resist late spring cold and germinate earlier while kept germination regularly, higher rate and seedlings quality. In contrast, single mulching using pine leaves or straw had poor soil moisture and temperature preserving, needed to irrigate every 12-day, meanwhile dropped the germination and booming time 14 days and 24-26 days, respectively, reduced germination rate about 11.3%-8.7%. However, single pine leaves mulching was better than straw mulching. In addition, though better effects of soil moisture and temperature preserving as well as earlier and higher rate of germination with single plastic films mulching had, some disadvantages had also been observed, such as daily soil temperature changed greatly, seedling bed soil hardened easily, more moss and weeds resulted difficulty in later management. To the purpose of saving water and labor as well as getting higher germination rate and seedlings quality, double mulching using plastic films combined pine leaves at the early time and single mulching removing plastic films at the later time is suggested to apply in the growing seedlings of P. notoginseng.

  2. Antimicrobial susceptibility testing in biofilm-growing bacteria.

    Science.gov (United States)

    Macià, M D; Rojo-Molinero, E; Oliver, A

    2014-10-01

    Biofilms are organized bacterial communities embedded in an extracellular polymeric matrix attached to living or abiotic surfaces. The development of biofilms is currently recognized as one of the most relevant drivers of persistent infections. Among them, chronic respiratory infection by Pseudomonas aeruginosa in cystic fibrosis patients is probably the most intensively studied. The lack of correlation between conventional susceptibility test results and therapeutic success in chronic infections is probably a consequence of the use of planktonically growing instead of biofilm-growing bacteria. Therefore, several in vitro models to evaluate antimicrobial activity on biofilms have been implemented over the last decade. Microtitre plate-based assays, the Calgary device, substratum suspending reactors and the flow cell system are some of the most used in vitro biofilm models for susceptibility studies. Likewise, new pharmacodynamic parameters, including minimal biofilm inhibitory concentration, minimal biofilm-eradication concentration, biofilm bactericidal concentration, and biofilm-prevention concentration, have been defined in recent years to quantify antibiotic activity in biofilms. Using these parameters, several studies have shown very significant quantitative and qualitative differences for the effects of most antibiotics when acting on planktonic or biofilm bacteria. Nevertheless, standardization of the procedures, parameters and breakpoints, by official agencies, is needed before they are implemented in clinical microbiology laboratories for routine susceptibility testing. Research efforts should also be directed to obtaining a deeper understanding of biofilm resistance mechanisms, the evaluation of optimal pharmacokinetic/pharmacodynamic models for biofilm growth, and correlation with clinical outcome. © 2014 The Authors Clinical Microbiology and Infection © 2014 European Society of Clinical Microbiology and Infectious Diseases.

  3. Minichromosome Maintenance Expression Defines Slow-Growing Gastroenteropancreatic Neuroendocrine Neoplasms

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    Simon Schimmack

    2016-10-01

    Full Text Available BACKGROUND: Small intestinal neuroendocrine neoplasm (SI-NEN proliferation is quantified by Ki67 measurements which capture G1-G2M phases of the cell cycle. G0 and early G1 phases, typical of slow-growing cells, can be detected by minichromosome maintenance protein (MCM expression. We hypothesized that these replication licensing markers may provide clinically relevant information to augment Ki67 in low-grade neuroendocrine neoplasia. METHODS: Immunohistochemical staining (IHC, Western blot analysis, quantitative polymerase chain reaction, and copy number variations of MCM2, MCM3, and Ki67 were undertaken in SI-NENs (n = 22. MCM and Ki67 expression was compared by Kaplan-Meier survival analysis (tissue microarray, independent set [n = 55]. Forty-three pancreatic NENs and 14 normal tissues were included as controls. RESULTS: In SI-NENs, MCM2 (mean: 21.2%: range: 16%-25% and MCM3 (28.7%: 22%-34% were detected in significantly more cells than Ki67 (2.3%: 0%-7%, P < .01. MCM2 mRNA correlated with Ki67 IHC (P < .05. MCM3 protein expression was higher in metastases (38-fold than in normal small intestine (P = .06 and was largely absent in normal neuroendocrine cells. There was considerable variation at the MCM copy number level (0-4 copies. MCM3 expression in proliferating cells significantly predicted overall survival (P < .002. Combinations of Ki67 and MCM2/3 in algorithms differentiated low and higher proliferative lesions (overall survival: 12 vs 6.1 years, P = .06. MCM expression was not informative in pancreatic NENs. CONCLUSION: MCMs are expressed in a higher proportion of NEN cells than Ki67 in slow-growing small intestinal lesions and correlate with survival. Assessment can be used to augment Ki67 to improve prognostic classification in these low-grade tumors.

  4. Forestry friendship : integrated land management gains growing support

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, A.W.

    2007-06-15

    This article addressed the small but growing number of responsible stewards of the planet who advocate a coordinated approach to industrial growth in Alberta, with particular focus on integrated land management between oil sand mining and the forestry sector. Although Canada's oil sand resource provides the United States and Canada with a secure, long-term source of oil, Alberta's northern boreal forest has been permanently changed in the process of mining and producing this resource. Integrated land management refers to a new awareness that acting in isolation often results in negative implications for other users of the land and their resource values. It was suggested that companies can effectively reduce their cumulative impact on the environment through cooperation. A computer model was developed at the Department of Biological Sciences at the University of Alberta to calculate the cumulative effects of future industrial development. A landscape cumulative effects simulator (ALCES) makes use of a massive relational database to demonstrate how the overlay of individual types of industrial development will affect a defined area. With ALCES, the computer displays a series of maps showing the effects of industrial footprint and population growth in successive 10-year segments. It was shown that oilsands mining has changed nearly 70,000 hectares of northeast Alberta, with a series of roads, pipelines, industrial buildings and seismic lines. A customized scenario was used by ALCES in which bitumen production was assumed to increase to 2.5 million barrels per day. The model result showed that by 2100, the size of the area affected by oil sand mining pits, disposal sites, tailing ponds, and end-pit lakes will grow to between 180,000 and 250,000 hectares. The benefits of coordinated planning between competitive oil companies working in the area that stretches from Fort McMurray to the Cold Lake area were showcased by the Alberta-Pacific Forestry Industries. 2

  5. Robustness of synthetic oscillators in growing and dividing cells

    Science.gov (United States)

    Paijmans, Joris; Lubensky, David K.; Rein ten Wolde, Pieter

    2017-05-01

    Synthetic biology sets out to implement new functions in cells, and to develop a deeper understanding of biological design principles. Elowitz and Leibler [Nature (London) 403, 335 (2000), 10.1038/35002125] showed that by rational design of the reaction network, and using existing biological components, they could create a network that exhibits periodic gene expression, dubbed the repressilator. More recently, Stricker et al. [Nature (London) 456, 516 (2008), 10.1038/nature07389] presented another synthetic oscillator, called the dual-feedback oscillator, which is more stable. Detailed studies have been carried out to determine how the stability of these oscillators is affected by the intrinsic noise of the interactions between the components and the stochastic expression of their genes. However, as all biological oscillators reside in growing and dividing cells, an important question is how these oscillators are perturbed by the cell cycle. In previous work we showed that the periodic doubling of the gene copy numbers due to DNA replication can couple not only natural, circadian oscillators to the cell cycle [Paijmans et al., Proc. Natl. Acad. Sci. (USA) 113, 4063 (2016), 10.1073/pnas.1507291113], but also these synthetic oscillators. Here we expand this study. We find that the strength of the locking between oscillators depends not only on the positions of the genes on the chromosome, but also on the noise in the timing of gene replication: noise tends to weaken the coupling. Yet, even in the limit of high levels of noise in the replication times of the genes, both synthetic oscillators show clear signatures of locking to the cell cycle. This work enhances our understanding of the design of robust biological oscillators inside growing and diving cells.

  6. Growing season methane budget of an Inner Mongolian steppe

    Science.gov (United States)

    Liu, Chunyan; Holst, Jirko; Yao, Zhisheng; Brüggemann, Nicolas; Butterbach-Bahl, Klaus; Han, Shenghui; Han, Xingguo; Tas, Bart; Susenbeth, Andreas; Zheng, Xunhua

    We present a methane (CH 4) budget for the area of the Baiyinxile Livestock Farm, which comprises approximately 1/3 of the Xilin river catchment in central Inner Mongolia, P.R. China. The budget calculations comprise the contributions of natural sources and sinks as well as sources related to the main land-use in this region (non-nomadic pastoralism) during the growing season (May-September). We identified as important CH 4 sources floodplains (mean 1.55 ± 0.97 mg CH 4-C m -2 h -1) and domestic ruminants, which are mainly sheep in this area. Within the floodplain significant differences between investigated positions were detected, whereby only positions close-by the river or bayous emitted large amounts of CH 4 (mean up to 6.21 ± 1.83 mg CH 4-C m -2 h -1). Further CH 4 sources were sheepfolds (0.08-0.91 mg CH 4-C m -2 h -1) and pasture faeces (1.34 ± 0.22 mg CH 4-C g -1 faeces dry weight), but they did not play a significant role for the CH 4 budget. In contrast, dung heaps were not a net source of CH 4 (0.0 ± 0.2 for an old and 0.0 ± 0.3 μg CH 4-C kg -1 h -1 for a new dung heap). Trace gas measurements along two landscape transects (volcano, hill slope) revealed expectedly a mean CH 4 uptake (volcano: 76.5 ± 4.3; hill: 28.3 ± 5.3 μg CH 4-C m -2 h -1), which is typical for the aerobic soils in this and other steppe ecosystems. The observed fluxes were rarely influenced by topography. The CH 4 emissions from the floodplain and the sheep were not compensated by the CH 4 oxidation of aerobic steppe soils and thus, this managed semi-arid grassland did not serve as a terrestrial sink, but as a source for this globally important greenhouse gas. The source strength amounted to 1.5-3.6 kg CH 4-C ha -1 during the growing season, corresponding to 3.5-8.7 kg C ha -1 yr -1.

  7. 317/319 phytoremediation site monitoring report - 2005 growing season.

    Energy Technology Data Exchange (ETDEWEB)

    Negri, M. C.; Gopalakrishnan, G.; Energy Systems

    2006-03-31

    In 1999, Argonne National Laboratory (ANL) designed and installed a series of engineered plantings consisting of a vegetative cover system and approximately 800 hybrid poplars and willows rooting at various predetermined depths. The plants were installed using various methods including Applied Natural Science's TreeWell{reg_sign} system. The goal of the installation was to protect downgradient surface and groundwater by hydraulic control of the contaminated plume by intercepting the contaminated groundwater with the tree roots, removing moisture from the upgradient soil area, reducing water infiltration, preventing soil erosion, degrading and/or transpiring the residual volatile organic compounds (VOCs), and removing tritium from the subsoil and groundwater. This report presents the results of the monitoring activities conducted by Argonne's Energy Systems Division (ES) in the growing season of 2005. Monitoring of the planted trees began soon after the trees were installed in 1999 and has been conducted every summer since then. As the trees grew and consolidated their growth into the contaminated soil and groundwater, their exposure to the contaminants was progressively shown through tissue sampling. However, as trees grow larger, some of the findings obtained in the early years when trees were much smaller may not hold true now and need to be verified again. During the 2005 sampling campaign, data from the French Drain area confirmed the results obtained in 2004 and earlier, and the previously found correlation between soil and branch concentrations. During the 2005 summer, studies under controlled conditions (cartridges) have shown a generally linear dose response of PCE uptake, and have also shown that tree concentrations of PCE decrease after flushing with clean water in short times when trees are exposed to low levels of the contaminant. This data proves that tree concentrations are transient, and that with proper time levels can return close to

  8. Nitroimidazole-refractory giardiasis: a growing problem requiring rational solutions.

    Science.gov (United States)

    Carter, E R; Nabarro, L E; Hedley, L; Chiodini, P L

    2018-01-01

    Giardia intestinalis is microaerophilic diarrhoea-causing protozoan common in countries with suboptimal sanitation. Standard treatment is with nitroimidazoles, but a growing number of refractory cases is being reported. Treatment failure has become increasingly prevalent in travellers who contract giardiasis in Asia. Clinicians are increasingly falling back on second-line and less well-known drugs to treat giardiasis. To review nitroimidazole-refractory G. intestinalis infection, examine the current efficacy of standard therapeutic agents, consider potential resistance mechanisms which could cause treatment failure and describe the practical aspects of managing this emerging clinical problem. A PubMed search was conducted using combinations of the following terms: refractory, Giardia, giardiasis, resistance and treatment. Articles on the pharmacotherapy, drug resistance mechanisms and use of alternative agents in nitroimidazole-refractory giardiasis were reviewed. We review the standard drugs for giardiasis, including their efficacy in initial treatment, mode of action and documented in vitro and in vivo drug resistance. We assess the efficacy of alternative drugs in nitroimidazole-refractory disease. Existing data suggest a potential advantage of combination treatment. An optimal treatment strategy for refractory giardiasis has still to be determined, so there is no standard treatment regimen for nitroimidazole-refractory giardiasis. Further work on drug resistance mechanisms and the use of drug combinations in this condition is a priority. Copyright © 2017. Published by Elsevier Ltd.

  9. Micromechanics and homogenization of inelastic composite materials with growing cracks

    Science.gov (United States)

    Costanzo, Francesco; Boyd, James G.; Allen, David H.

    1996-03-01

    A homogenization scheme is employed to derive the effective constitutive equations of an elastoplastic composite system with growing damage. The homogenization procedure followed herein is based on the thermodynamics of dissipative media. It is shown that when damage consists of sharps microcracks the macroscopic constitutive behavior is that of a so-called generalized standard material. The latter is a general dissipative medium whose constitutive equations are completely characterized by a single scalar convex potential function of the chosen state variables and whose evolution is completely characterized by a single convex dissipation potential function of the thermodynamic forces conjugate to the chosen internal state variables. The analysis presented is valid under the assumption that the evolution of the representative volume element at hand is unique and stable. The results of the theoretical analysis are then employed for formulating an approximate method for practically deriving the macroscopic constitutive equations. Computer software development for the application of said method is currently ongoing. A simple example of the numerical results obtained so far is presented.

  10. Genetic Diversity of Some Capparis L. Species Growing in Syria

    Directory of Open Access Journals (Sweden)

    Bassam Al- Safadi

    2014-12-01

    Full Text Available This work investigated the genetic diversity and relationships among Capparis species growing in Syria using IRAP and ISSR techniques. Forty-seven samples of three Capparis species genotypes were collected from 21 different locations in Syria. The genotypes were morphologically identified based on the descriptions available in the literature. When IRAP technique was used, an average of 71.5% of the amplified fragments were polymorphic compared to 82.04% in ISSR. Morphological characterization along with the cluster and PCoA analyses of the data divided the studied genotypes into three groups. The groups included genotypes identified as Capparis spinosa L, C. sicula Duh., and C. aegyptia Lam. Based on the morphological description, molecular studies and statistical analyses of this study, C. aegyptia could be suggested as a separate species and not a varietal rank of C. spinosa(C. spinosa var. aegyptia (Lam.. Two samples (Alep1 and Idl were not placed in any of the three distinctive groups, despite their closeness morphologically to C. spinosa. In PCoA analysis, sample Alep1 came between C. sicula and C. spinosa and Idl was placed between C. sicula and C. aegyptia. Although hybridization between Capparis species could occur, it was not clear from the present study if these two genotypes were hybrids.

  11. Pharmaceutical Industry in Vietnam: Sluggish Sector in a Growing Market

    Directory of Open Access Journals (Sweden)

    Antonio Angelino

    2017-08-01

    Full Text Available Vietnam is a fast growing economy in the Asian region with a significantly high population (over 92 million in 2015. Although still expanding (about 1.1% on average during 2000–2015, the Vietnamese population is considered to be entering the ageing stage at a very high rate. The rapid expansion of the middle-income urban class and the ageing people ratio have dramatically pushed up the demand for healthcare goods, particularly in terms of pharmaceutical products. Since the early 1990s the government has addressed the necessities of rising demand for healthcare products by formulating a series of policies aimed at promoting the development of the pharmaceutical industry. However, the implementation of such policies does not seem to have been completely efficient given that the country still needs to import up to 90% of its pharmaceutical consumption. This paper aims to explore the development of the pharmaceutical industry during the years 1990–2015 and to identify a series of weaknesses in the government promotion of the industry. Future developments will also be discussed on how the Vietnamese pharmaceutical industry could increase its participation in the regional supply chain, which is currently being dominated by big players like India and China.

  12. Slow-growing melanoma: Report of five cases.

    Science.gov (United States)

    Roma, Paolo; Savarese, Imma; Martino, Antonia; Martino, Domenico; Annese, Pietro; Capoluongo, Patrizio; Mordente, Ines; Nicolino, Rachele; Zalaudek, Iris; Argenziano, Giuseppe

    2007-12-29

    Epidemiologic data on melanoma reveal a considerable increase in incidence, especially of the early forms (melanoma in situ and early invasive melanoma), but the mortality rates are relatively stable. These data suggest the hypothesis of the existence of a melanoma with less aggressive biological behaviour. This hypothesis is, however, hard to be proven if the assumption is true that more and less aggressive melanomas very often exhibit overlapping clinical and histopathologic features. Digital dermoscopic imaging techniques permit today a detailed documentation of lesions over time and, therefore, represent an optimal tool to disclose the natural evolution of a given lesion. We present five case of slow-growing melanomas observed during a long-term period of follow-up. Five pigmented skin lesions from five patients with multiple atypical melanocytic nevi were examined at the baseline consultation and digital pictures were taken for monitoring purposes. The lesions have been followed-up for a long time because of the absence of significant changes over time. After a variable period of follow-up (1 to 10 years) all lesions were finally removed and subsequent histopathologic examination revealed early stage melanoma in all cases. Dermoscopy and digital follow up might be the key factors to improve the knowledge about the natural evolution of nevi and melanoma and the spectrum of undefined melanocytic proliferations.

  13. Violence: a growing danger to children. The American case.

    Science.gov (United States)

    Sayre, J W

    1994-01-01

    A frightening, growing epidemic of senseless, irrational and inexcusable violence has seized the United States. While it involves all ages and localities, the occurrences are predominantly in areas of poverty, poor housing and unemployment. Children, particularly the adolescent and young adult male black population, are at greatest risk. There are recognized many contributing forces such as low self-esteem, family disruption and single parenting. Country-wide there is easy access to guns and lack of gun safety guards. Violent television sets an example for our youth and lends an air of adventure and excitement to their lives. The solution to this enormous problem is clearly not an easy one and must be through a combination of many social and legal changes. This is most assuredly a medical problem and demands thought and active participation by physicians. There are a number of strategies for physicians, especially pediatricians. We must look carefully at family interactions, attempting to promote more kindly behaviors, enhance self-esteem. School-age children can be helped through office discussions and collaboration with teachers. "Leave the knives and guns at home, avoid noisy arguments, use more kindly words." "Television is not real life; the actors do not die." These are our people. Their needs are great. We must help.

  14. Growing-up milk: a necessity or marketing?

    Science.gov (United States)

    Przyrembel, Hildegard; Agostoni, Carlo

    2013-01-01

    Growing-up milk (GUM) products intended for children between 1 and 3 years of age are increasingly being introduced into the diets of young children. Although not a necessity for adequate nutrition of that age group, they can compensate for nutritional deficiencies which may occur in the transition phase of infant nutrition to family food, particularly when bad dietary patterns prevail in the family. For that purpose, GUM should be composed to decrease the overall protein intake which tends to be higher than the reference values for that age. This can be achieved by diluting fat-reduced cow's milk to a protein level comparable to infant or follow-on formulae and by partially replacing cow's milk fat with appropriate vegetable oils to increase the content of essential fatty acids and possibly by adding long-chain polyunsaturated fatty acids, docosahexaenoic and arachidonic acids whilst preserving the content of some minerals (such as calcium and phosphorus) and vitamins (B2 and B12) well represented in cow's milk. The content of iron, iodine, zinc and the vitamins A and D should be the same as in a follow-on formula. Based on available evidence, GUM should not be promoted as a necessity in the nutrition of young children. Copyright © 2013 S. Karger AG, Basel.

  15. Pharmaceutical Industry in Vietnam: Sluggish Sector in a Growing Market.

    Science.gov (United States)

    Angelino, Antonio; Khanh, Do Ta; An Ha, Nguyen; Pham, Tuan

    2017-08-29

    Vietnam is a fast growing economy in the Asian region with a significantly high population (over 92 million in 2015). Although still expanding (about 1.1% on average during 2000-2015), the Vietnamese population is considered to be entering the ageing stage at a very high rate. The rapid expansion of the middle-income urban class and the ageing people ratio have dramatically pushed up the demand for healthcare goods, particularly in terms of pharmaceutical products. Since the early 1990s the government has addressed the necessities of rising demand for healthcare products by formulating a series of policies aimed at promoting the development of the pharmaceutical industry. However, the implementation of such policies does not seem to have been completely efficient given that the country still needs to import up to 90% of its pharmaceutical consumption. This paper aims to explore the development of the pharmaceutical industry during the years 1990-2015 and to identify a series of weaknesses in the government promotion of the industry. Future developments will also be discussed on how the Vietnamese pharmaceutical industry could increase its participation in the regional supply chain, which is currently being dominated by big players like India and China.

  16. Cytotoxic Activity of Alkaloids from Papaver rhoeas growing in Lebanon

    Directory of Open Access Journals (Sweden)

    Mohamad Ali Hijazi

    2017-03-01

    Full Text Available This paper represents the phytochemical properties of Lebanese Papaver rhoeas, from which five protopine alkaloids are isolated, namely; stylopine (1, canadine (2, sinactine (3, berberine (4, and epiberberine (5. This is the first report for the isolation of epiberberine (5 from the genus Papaver and canadine (2 from Papaver rhoeas, suggesting a new chemotype of Papaver rhoeas growing in Lebanon. The cytotoxic activity of the total ethanolic extract and the isolated alkaloids were determined by MTT assay on human colon cancer cells (HCT116, breast cancer cells (MCF7, human keratinocyte cell line (HaCaT, and non-cancerous colon cells (NCM460. The compounds showed dose-dependent inhibitory effect with highest activity for compound 4 against all cell lines. The activity of the alkaloids varied between the various cell lines indicating cell type specificity and suggesting different cell-compound interactions. IC 50 values on normal cells was higher than cancer cell lines (>200 µM, indicating the selectivity of these compounds to cancer cells. It was noticed that the presence of methylenedioxy group at positions C-2 and C-3 rather than at position C-9 and C-10 potentiated the compound’s cytotoxic activity. Further studies are underway to explore the activity of these compounds at the molecular level.

  17. Hidden treasures in stem cells of indeterminately growing bilaterian invertebrates.

    Science.gov (United States)

    Vogt, Günter

    2012-06-01

    Indeterminate growth, the life-long growth without fixed limits, is typical of some evolutionarily very successful aquatic invertebrate groups such as the decapod crustaceans, bivalve molluscs and echinoderms. These animals enlarge their organs also in the adult life period and can regenerate lost appendages and organs, which is in sharp contrast to mammals and most insects. Interestingly, decapods, bivalves and echinoderms develop only rarely neoplastic and age-related diseases, although some species reach ages exceeding 100 years. Their stem cell systems must have co-evolved with these successful life histories suggesting possession of unknown and beneficial features that might open up new vistas in stem cell biology. Research of the last decade has identified several adult stem cell systems in these groups and also some mature cell types that are capable to dedifferentiate into multipotent progenitor cells. Investigation of stem and progenitor cells in indeterminately growing bilaterian invertebrates is assumed beneficial for basic stem cell biology, aquaculture, biotechnology and perhaps medicine. The biggest treasure that could be recovered in these animal taxa concerns maintenance of stem cell niches and fidelity of stem cell division for decades without undesirable side effects such as tumour formation. Uncovering of the underlying molecular and regulatory mechanisms might evoke new ideas for the development of anti-ageing and anti-cancer interventions in humans.

  18. Tobacco growing and the sustainable development goals, Malawi.

    Science.gov (United States)

    Kulik, Margarete C; Bialous, Stella Aguinaga; Munthali, Spy; Max, Wendy

    2017-05-01

    Negative impacts of tobacco result from human consumption and from tobacco-growing activities, most of which now occur in low- and middle-income countries. Malawi is the world's largest producer of burley tobacco and its population is affected by the negative consequences of both tobacco consumption and production. In countries like Malawi, tobacco control refers to control of the tobacco supply chain, rather than control of consumption. We review the impact of tobacco cultivation, using Malawi as an example, to illustrate the economic, environmental, health and social issues faced by low- and middle-income countries that still produce significant tobacco crops. We place these issues in the context of the sustainable development goals (SDGs), particularly 3a which calls on all governments to strengthen the implementation of the World Health Organization Framework Convention on Tobacco Control. Other goals address the negative effects that tobacco cultivation has on development. The SDGs offer an opportunity for low- and middle-income countries that are dependent on tobacco production and that are not yet parties to the Convention, to reconsider joining the FCTC.

  19. Culturable fungal assemblages growing within Cenococcum sclerotia in forest soils.

    Science.gov (United States)

    Obase, Keisuke; Douhan, Greg W; Matsuda, Yosuke; Smith, Matthew E

    2014-12-01

    The ectomycorrhizal fungus Cenococcum geophilum (Ascomycota, Dothideomycetes) forms black, round to irregular sclerotia in forest soils. Fungi that colonize the sclerotia appear to affect sclerotia viability and may play an important role in the life history of Cenococcum. Some of the fungi could also affect nutrient cycling by decomposing Cenococcum sclerotia, which are melanized and recalcitrant to decay. We used a culture-based method to document the fungal communities growing inside surface-sterilized sclerotia that were collected from forest soils. Cenococcum was successfully isolated from 297 of 971 sclerotia whereas 427 sclerotia hosted fungi other than Cenococcum. DNA barcoding of the internal transcribed spacer rDNA followed by grouping at 97% sequence similarity yielded 85 operational taxonomic units (OTUs) that consisted primarily of Ascomycota (e.g. Chaetothyriales, Eurotiales, Helotiales, Pleosporales) and a few Basidiomycota and Mucoromycotina. Although most fungal OTUs were infrequently cultured, several OTUs such as members of Asterostroma, Cladophialophora, Oidiodendron, and Pleosporales were common and found across many sites. Our results suggest that Cenococcum sclerotia act as a substrate for diverse fungi. The occurrence of several OTUs in sclerotia across many sites suggests that these fungi may be active parasites of Cenococcum sclerotia or may preferentially use sclerotia as a nutrient source. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  20. Growing networks of overlapping communities with internal structure

    Science.gov (United States)

    Young, Jean-Gabriel; Hébert-Dufresne, Laurent; Allard, Antoine; Dubé, Louis J.

    2016-08-01

    We introduce an intuitive model that describes both the emergence of community structure and the evolution of the internal structure of communities in growing social networks. The model comprises two complementary mechanisms: One mechanism accounts for the evolution of the internal link structure of a single community, and the second mechanism coordinates the growth of multiple overlapping communities. The first mechanism is based on the assumption that each node establishes links with its neighbors and introduces new nodes to the community at different rates. We demonstrate that this simple mechanism gives rise to an effective maximal degree within communities. This observation is related to the anthropological theory known as Dunbar's number, i.e., the empirical observation of a maximal number of ties which an average individual can sustain within its social groups. The second mechanism is based on a recently proposed generalization of preferential attachment to community structure, appropriately called structural preferential attachment (SPA). The combination of these two mechanisms into a single model (SPA+) allows us to reproduce a number of the global statistics of real networks: The distribution of community sizes, of node memberships, and of degrees. The SPA+ model also predicts (a) three qualitative regimes for the degree distribution within overlapping communities and (b) strong correlations between the number of communities to which a node belongs and its number of connections within each community. We present empirical evidence that support our findings in real complex networks.

  1. Finite size induces crossover temperature in growing spin chains

    Science.gov (United States)

    Sienkiewicz, Julian; Suchecki, Krzysztof; Hołyst, Janusz A.

    2014-01-01

    We introduce a growing one-dimensional quenched spin model that bases on asymmetrical one-side Ising interactions in the presence of external field. Numerical simulations and analytical calculations based on Markov chain theory show that when the external field is smaller than the exchange coupling constant J there is a nonmonotonous dependence of the mean magnetization on the temperature in a finite system. The crossover temperature Tc corresponding to the maximal magnetization decays with system size, approximately as the inverse of the Lambert W function. The observed phenomenon can be understood as an interplay between the thermal fluctuations and the presence of the first cluster determined by initial conditions. The effect exists also when spins are not quenched but fully thermalized after the attachment to the chain. By performing tests on real data we conceive the model is in part suitable for a qualitative description of online emotional discussions arranged in a chronological order, where a spin in every node conveys emotional valence of a subsequent post.

  2. Avocado oils and hepatic lipid metabolism in growing rats.

    Science.gov (United States)

    Werman, M J; Neeman, I; Mokady, S

    1991-02-01

    The effect of various avocado oils on liver metabolism was studied in growing female rats. The rats were fed diets containing 10% (w/w) avocado oil for 4 wk. In comparison with rats fed refined avocado oil obtained from cored fruit by centrifugal separation, rats fed unrefined avocado oil obtained by organic solvent extraction from intact fruit, or its unsaponifiable components, showed a significant increase in total liver lipogenesis as well as in phospholipid and triglceride synthesis. Rats fed avocado-seed oil exhibited enhanced [1-14C]acetate incorporation into total liver lipids but showed the same distribution of label in the three main lipid classes as that of rats fed refined avocado oil. In addition, a significant reduction of triglycerides and protein content of plasma very-low-density lipoprotein and high-density lipoprotein fractions was observed in rats fed avocado-seed oil as compared with rats fed refined oil. Electron micrographs suggested that the alterations in hepatic lipogenesis are related to the marked proliferation of the smooth endoplasmic reticulum, which is known to be associated with induction of enzymes involved with lipid biosynthesis. The differences between the animals fed seed oil and those fed the unrefined oils, in the distribution of label within the main lipid classes, indicate that more than one factor is involved in the alterations caused by these oils.

  3. Growing our own: building a native research team.

    Science.gov (United States)

    Gray, Jacqueline S; Carter, Paula M

    2012-01-01

    In 2006, American Indian/Alaska Natives (AI/AN) made up less than 1% of the science, engineering and health doctorates in the U.S. Early introduction of AI/AN students to research and continued opportunities are necessary to develop successful AI/AN researchers who can better serve their communities. This team was developed to form a cohort of American Indian students, staff and faculty interested in research and becoming researchers. Since implementation, the program grew from one student to over 20 AI students ranging from freshmen just entering college to doctoral students working to complete their dissertations. This article highlights the team growth, increasing structure, student needs and the faculty and staff involved. It further addresses the support and educational aspects of growing an ongoing, multidisciplinary research team committed to ethical research in Native communities. The team addresses substance use prevalence, the relationship of substance abuse to other mental health diagnoses, and treatment issues. The team includes weekly team meetings, a Blackboard site on the Internet that is populated with resources and focused on sharing materials and information, a weekly journal club discussion of research articles, and collaborative discussions on each project and the barriers and challenges that need to be addressed to move forward.

  4. Growing or connecting? An urban food garden in Johannesburg.

    Science.gov (United States)

    Wills, Jane; Chinemana, Frances; Rudolph, Michael

    2010-03-01

    Issues of food security are of particular importance in urban areas in Africa and government policy advises on the household growing of vegetables for nutrition. The Siyakhana project is a food garden in the centre of Johannesburg which was established by a University Health Promotion Unit with the support of other stakeholders including the City authorities and a permaculture organization. It was set up with the objective of providing food for children attending early-childhood development centres and for the beneficiaries of non-governmental organizations providing home-based care for people living with HIV/AIDS. One year after start-up, an evaluation was conducted, based on the measures of outcome identified as significant by those involved in the project. Its impact on health is not yet measurable, but as the amounts of fruits and vegetables available and consumed in South Africa are low compared with WHO recommendations, it is a useful addition to food security in an urban area. Mobilizing around the food garden supported bonding among homogenous but separate third-sector organizations, through increased opportunities for networking which built trust, reciprocity and resource exchange. The project also provides a model for a community-university partnership providing opportunities for service learning by students and for social investment by the university.

  5. Effect of feed restriction on performance of growing rabbits

    Directory of Open Access Journals (Sweden)

    Maria Cristina de Oliveira

    2012-06-01

    Full Text Available This experiment assessed the effect of feed restriction in rabbits on performance and economic viability of the activity. Sixty New Zealand White rabbits, weaned at 33 days and slaughtered at 81 days of age, were used. The design was of randomized blocks with four treatments and five replications. The treatments were, as follows: 1 - free feeding, 2 - feed restriction from 35 to 40 days of age (50 g/d/rabbit, 3 - feed restriction from 54 to 61 days of age (90 g/d/rabbit and 4 - feed restriction from 33 to 40 days (50 g/d/rabbit and from 54 to 61 days of age (90 g/d/rabbit. There was no difference in the performance and carcass parameters, indicating that there was compensatory growth in the rabbits that suffered feed restriction. The best gross margin was obtained with feed restriction from 54 to 61 days age. Feed restriction in growing rabbits can be adopted at different ages because it does not interfere negatively in the performance and carcass parameters. In two periods and from 51 to 61 days, feed restriction was more economically viable for the sale of live and slaughtered rabbits, respectively.

  6. Restoration of red mud deposits by naturally growing vegetation.

    Science.gov (United States)

    Mishra, Tripti; Singh, N B; Singh, Nandita

    2017-05-04

    Disposal of red mud (RM) poses serious environmental problems such as wind erosion, air and water pollution. To overcome these problems, effective restoration of the disposal land through naturally growing vegetation is a sustainable and economical approach. The present study involved estimation of frequency (F), density (D), abundance (Ab), and important value index (IVI) of natural flora on abandoned RM sites in order to assess their metal toxicity tolerance capacity. Based on visual observations and highest IVI, S. Asper and S. punicea were identified as effective ecological tools for the restoration of barren RM sites. From the study, remarkable differences were observed between non-rhizospheric and rhizospheric RM of both species. These rhizospheric RM analyses confirm the ability of S. asper and S. punicea for enhancing the biological activities of abandoned RM. Translocation factor (TF) of iron was maximum (2.58) in S. asper, and bioconcentration factor (BCF) was found maximum (1.25) in S. punicea, but both TF (2.58) and BCF (1.35) were high in S. asper. Therefore, this plant could be reported as an iron hyperaccumulator plant. These results suggest that these plant species can be exploited for effective restoration of RM deposited land without any inputs or maintenance.

  7. The growing impact of satellite data in daily life

    Science.gov (United States)

    Stramondo, Salvatore

    2015-04-01

    Satellite images have a growing role in our daily life. Weather previsions, telecommunications, environmental planning, disaster mitigation and monitoring: these are only some of the fieldworks where space remote sensing data, and related processing techniques, provide extremely useful information to policy/decision makers, scientists, or to the "simple" citizen. The demonstration of the level of attention provided by the International Community to the impact of new technologies and satellite Earth Observation, in particular, onto everyday life is testified by the recent and forthcoming project calls. Horizon 2020, for instance, identified "Societal challenges" and "Science with and for Society" among the main pillars. In sub-themes we may read references to the "Environment", "Secure societies", "Climate changes", and many others, most of which soliciting the use of remote sensing technologies. In such scenario the scientists should be conscious about the capabilities and the implications in applying new technologies. Recent examples might be explanatory. Satellite data properly managed can be used to measure millimetric and/or centimetric movements of buildings and infrastructures. It has been demonstrated how long term monitoring of urban areas detecting pre-collapse deformations might provide useful hints to prevent such dramatic events. Or, in different frameworks, satellite data can be an advanced instrument for intelligence and military purposes. With such premises, ethic issues assume a key role to properly address the use of satellite technologies.

  8. Growing sensitivity of maize to water scarcity under climate change.

    Science.gov (United States)

    Meng, Qingfeng; Chen, Xinping; Lobell, David B; Cui, Zhenling; Zhang, Yi; Yang, Haishun; Zhang, Fusuo

    2016-01-25

    Climate change can reduce crop yields and thereby threaten food security. The current measures used to adapt to climate change involve avoiding crops yield decrease, however, the limitations of such measures due to water and other resources scarcity have not been well understood. Here, we quantify how the sensitivity of maize to water availability has increased because of the shift toward longer-maturing varieties during last three decades in the Chinese Maize Belt (CMB). We report that modern, longer-maturing varieties have extended the growing period by an average of 8 days and have significantly offset the negative impacts of climate change on yield. However, the sensitivity of maize production to water has increased: maize yield across the CMB was 5% lower with rainfed than with irrigated maize in the 1980s and was 10% lower (and even >20% lower in some areas) in the 2000s because of both warming and the increased requirement for water by the longer-maturing varieties. Of the maize area in China, 40% now fails to receive the precipitation required to attain the full yield potential. Opportunities for water saving in maize systems exist, but water scarcity in China remains a serious problem.

  9. Growing up with a cochlear implant: education, vocation, and affiliation.

    Science.gov (United States)

    Spencer, Linda J; Tomblin, J Bruce; Gantz, Bruce J

    2012-01-01

    The long-term educational/vocational, affiliation, and quality-of-life outcomes of the first and second cohorts of children with bilateral, profound hearing loss who received cochlear implants under a large National Institutes of Health-funded study was investigated in 41 of 61 eligible participants. Educational and vocational outcomes were collected from user survey data. Affiliation and quality-of-life data were collected from the Satisfaction-with-Life scale and the Deaf Identity Scale. Qualitative results indicated that compared with their hearing, adult-age peers, this group obtained high educational achievement, and they reported a very high satisfaction of life. With respect to forming an identity in these first 2 cohorts of cochlear implant users, we found that most of the individuals endorsed a dual identity, which indicates they feel just as comfortable with Deaf individuals as they do with hearing individuals. Quantitative results revealed a significant relationship between ability to hear and ability to speak, in addition to consistency of device use. Additional relationships were found between mother's and the individual's educational statuses, hearing scores, and communication system used. Younger individuals scored higher on satisfaction-with-life measures, and they also tended to endorse a dual identity more often. Taken together, these findings diminish concerns that profoundly deaf individuals growing up with cochlear implants will become culturally bereft and unable to function in the hearing world.

  10. Biotechnology and genetic optimization of fast-growing hardwoods

    Energy Technology Data Exchange (ETDEWEB)

    Garton, S.; Syrkin-Wurtele, E.; Griffiths, H.; Schell, J.; Van Camp, L.; Bulka, K. (NPI, Salt Lake City, UT (United States))

    1991-02-01

    A biotechnology research program was initiated to develop new clones of fast-growing Populus clones resistant to the herbicide glyphosate and resistant to the leaf-spot and canker disease caused by the fungus Septoria musiva. Glyphosate-resistant callus was selected from stem segments cultured in vitro on media supplemented with the herbicide. Plants were regenerated from the glyphosate-resistant callus tissue. A portion of plants reverted to a glyphosate susceptible phenotype during organogenesis. A biologically active filtrate was prepared from S. musiva and influenced fresh weight of Populus callus tissue. Disease-resistant plants were produced through somaclonal variation when shoots developed on stem internodes cultured in vitro. Plantlets were screened for disease symptoms after spraying with a suspension of fungal spores. A frequency of 0.83 percent variant production was observed. Genetically engineered plants were produced after treatment of plant tissue with Agrobacterium tumefasciens strains carrying plasmid genes for antibiotic resistance. Transformers were selected on media enriched with the antibiotic, kanamycin. Presence of foreign DNA was confirmed by Southern blot analysis. Protoplasts of popular were produced but did not regenerate into plant organs. 145 refs., 12 figs., 36 tabs.

  11. Growing tropical forage legumes in full sun and silvopastoral systems

    Directory of Open Access Journals (Sweden)

    Saulo Alberto do Carmo Araújo

    2017-02-01

    Full Text Available Growth was evaluated three tropical forage legumes in two cropping systems: silvopastoral system (SSP and full sun. A completely randomized design was adopted in factorial three legumes (estilosanthes cv. Campo Grande (Stylozanthes macrocephala x Stylozanthes capitata, tropical kudzu (Pueraria phaseoloides (Roxb. Benth and macrotiloma (Macrotyloma axillare cv. Java x two farming systems, with 4 repetitions. A eucalyptus SSP already deployed, with spatial arrangement of 12 x 2 m between trees was used. Legumes were planted in January 2014 a uniform cut being made in May 2014. The court assessment was carried out 125 days after the uniformity cut. There was difference for mass production of dry legumes (PMMSL between cultivation systems, evidencing increased productivity in the farming full sun. The macrotiloma showed higher PMSL (5.29 kg DM ha-1 cut-1, while the kudzu obtained the lowest yield (3.42 kg DM ha-1 cut-1 in the sun growing full. The cultivation of legumes in SSP increased the levels of mineral matter, crude protein and neutral detergent fiber. The shade provided by the SSP caused a reduction in the mass of dry matter production, but also altered the chemical composition of the studied legumes.

  12. Yeast diversity on grapes in two German wine growing regions.

    Science.gov (United States)

    Brysch-Herzberg, Michael; Seidel, Martin

    2015-12-02

    The yeast diversity on wine grapes in Germany, one of the most northern wine growing regions of the world, was investigated by means of a culture dependent approach. All yeast isolates were identified by sequence analysis of the D1/D2 domain of the 26S rDNA and the ITS region. Besides Hanseniaspora uvarum and Metschnikowia pulcherrima, which are well known to be abundant on grapes, Metschnikowia viticola, Rhodosporidium babjevae, and Curvibasidium pallidicorallinum, as well as two potentially new species related to Sporidiobolus pararoseus and Filobasidium floriforme, turned out to be typical members of the grape yeast community. We found M. viticola in about half of the grape samples in high abundance. Our data strongly suggest that M. viticola is one of the most important fermenting yeast species on grapes in the temperate climate of Germany. The frequent occurrence of Cu. pallidicorallinum and strains related to F. floriforme is a new finding. The current investigation provides information on the distribution of recently described yeast species, some of which are known from a very few strains up to now. Interestingly yeasts known for their role in the wine making process, such as Saccharomyces cerevisiae, Saccharomyces bayanus ssp. uvarum, Torulaspora delbrueckii, and Zygosaccharomyces bailii, were not found in the grape samples. Copyright © 2015. Published by Elsevier B.V.

  13. Interest grows in African oil and gas opportunities

    Energy Technology Data Exchange (ETDEWEB)

    Knott, D.

    1997-05-12

    As African countries continue a slow drift towards democratic government and market economics, the continent is increasingly attractive to international oil and gas companies. Though Africa remains politically diverse, and its volatile politics remains a major barrier to petroleum companies, a number of recent developments reflect its growing significance for the industry. Among recent projects and events reflecting changes in Africa: oil and gas exporter Algeria has invited foreign oil companies to help develop major gas discoveries, with a view to boosting exports to Europe; oil and gas producer Egypt invited foreign companies to explore in the Nile Delta region, and the result appears to be a flowering world scale gas play; west African offshore exploration has entered deep water and new areas, and a number of major projects are expected in years to come; Nigeria`s reputation as a difficult place to operate has been justified by recent political and civil events, but a long-planned liquefied natural gas (LNG) export plant is being built there; South Africa, which has returned to the international scene after years of trade isolation because of apartheid, is emerging as a potential driver for energy industry schemes throughout the continent. Activities are discussed.

  14. JASAL Forum 2011: Growing Trends in Self-Access Learning

    Directory of Open Access Journals (Sweden)

    Azusa Kodate

    2012-03-01

    Full Text Available The annual JASAL forum was held in Tokyo in 2011 in keeping with the theme of the JALT 2011 conference, ‘Teaching, Learning, and Growing’.Drawing on the theme of this year’s JASAL forum, ‘Growing Trends in Self-Access Learning’, several different trends emerged from the two paper and five poster presentations that illustrate the ongoing growth of the field. Contents of the presentations varied widely from an administrative operation of a self-access centre (hereafter SAC to research findings about SAC users. Having approximately 45 people including presenters at the forum, active discussions in which they shared ideas and professional practices were generated. One of the common points which emerged in the forum was that the form of learning that SACs provide is becoming more accepted and valued by educational institutions, and this has led to an increase in the number of SACs nationwide in Japan. Against this background, three themes were evident in the presentations given at this year’s forum: focusing on the physical learning environment, providing easier access to learners, and supporting learning processes.

  15. Shear bands as growing instabilities in viscoanelastic media with memory

    Directory of Open Access Journals (Sweden)

    Marina Dolfin

    2013-09-01

    Full Text Available In this paper we investigate the critical conditions under which a small perturbation in an homogeneous continuum can possibly grows into a shear band instability. In particular, we analyze from a thermodynamical viewpoint the phenomenon of shear bands in viscoanelastic media with memory. It is emphasized, in the scientific literature, that the specific adopted rheology strongly affects the results so that a special attention has to be paid, also for engineering purposes, to the accuracy of the rheological model. Several well-known rheological model (for instance the so called Maxwell or Jeffreys media are particular cases of the general model we adopt in the paper to analyze shear bands. Instability conditions, giving rise to shear bands formation, are obtained by introducing small perturbations around an homogeneous deformation into the system of differential equations governing the problem of homogeneous deformations in the considered continuous medium; as a result a non-homogeneous linear dynamical system is obtained whose stability is analyzed. A research perspective in view of a possible comparison with experimental results is proposed; in particular the simple methodology proposed in the paper should be applied in view of using the phenomenon of the initiation of shear bands to calculate the thermomechanical coefficients of real materials.

  16. Essential oil composition of wild growing Sage from R. Macedonia

    Directory of Open Access Journals (Sweden)

    Gjoshe Stefkov

    2012-03-01

    Full Text Available The main objective of this study was to analyze and identify the essential oil composition of S. officinalis populations growing in Republic of Macedonia and to evaluate these data according to different standards’ requirements for, commercially most utilized, Dalmatian sage. The essential oil yield, obtained after hydrodestilation from leaves, of three different populations of Salvia officinalis L. from Republic of Macedonia was determined, varying from 1.40 to 3.46%. The GC/FID/MS analysis of the composition of the essential oils revealed 63, 57 and 51 components in Galicica Mtn., Jablanica Mtn. and Karaorman Mtn. sage populations, respectively. The main components of the oil, in all three samples, were the terpene hydrocarbons, encompassing the monoterpenes: camphor (13.15 - 25.91%, α-thujone (19.25 - 26.33%, β-thujone (2.03 - 5.28%, 1,8-cineole (6.51 – 13.60%, α-pinene (0.93 – 1.47%, borneol (1.07 – 4.67%, then sesquiterpenes: trans (E-caryophyllene (1.72 – 5.33%, α-humulene (2.89 – 7.99%, viridiflorol (4.27 – 7.99%, and the diterpene manool (2.13 - 3.79%. Thus, our results for the essential oil composition of sage complied with the reference values specified in the DAC 86 monograph for Salvia essential oil.

  17. Narrative Silences Between History and Memory in Schumann's Being Present: Growing Up in Hitler's Germany

    National Research Council Canada - National Science Library

    Rothe, Anne; Rothe, Anne

    2009-01-01

    ...: Growing Up in Hitler's Germany" Anne Rothe analyzes Willy Schumann's 1991 memoir as an instance of a growing sub-genre among autobiographical writing on the Third Reich and the Holocaust, the Hitler...

  18. A Growing and Expanding Earth is no Longer Questionable

    Science.gov (United States)

    Myers, L. S.

    2008-05-01

    The young age of today's oceans is absolute proof that the Earth has been growing and expanding for the past 250 million years. Today, these young oceans now cover approximately 71% of Earth's surface and have added about 40% to its size. That fact, alone, is proof that Kant's nebular hypothesis is false, and that the Earth has been increasing in size and mass for the past 250 million years. Growth and expansion of the Earth can no longer be refuted. Ocean sediments cored from basaltic basement floors by the Deep Sea Drilling Program (DSDP) and its successors confirm that all of today's oceans are relatively young and could not have been present when the planet was first created, as postulated by Kant's nebular hypothesis (1755), modified by Laplace in 1796, which holds that the Earth and other planets were created approximately 4.6 billion years ago with their present sizes and chemical composition. The nebular hypothesis has no evidence to support it and is easily disproved. This discovery has immense consequences for current scientific beliefs, primarily the concepts of plate tectonics and subduction to maintain a static Earth diameter. Plate tectonics philosophy is basically correct, but its mechanism of subduction will prove to be the most avoidable and egregious error in the history of geophysics. A new cosmological concept called Accreation (creation by accretion) is offered to replace Kant's false philosophy of creation of the Earth and Solar System. Accreation, fundamentally, is based on the known daily influx of large tonnages of meteorites, particles and dust from outer space. An age for the Earth is impossible to estimate because a plausible starting point cannot be determined. Scientists of the world must face up to other erroneous hypotheses generated by Kant's false philosophy and recognize that a paradigm shift equal to that wrought by Copernicus is now in order. The benefits to scientific knowledge are inestimable, and science will henceforth be

  19. Rapidly Growing Esophageal Carcinosarcoma Reduced by Neoadjuvant Radiotherapy Alone

    Directory of Open Access Journals (Sweden)

    Naotaka Ogasawara

    2014-06-01

    Full Text Available Esophageal carcinosarcoma is a rare malignant neoplasm consisting of both carcinomatous and sarcomatous components. It is generally treated by surgery, radiotherapy and chemotherapy according to the protocols used for other esophageal cancers. However, the treatment of esophageal carcinosarcoma by radiotherapy alone before surgery has not been previously described. We report a patient with a rapidly growing esophageal carcinosarcoma that was efficiently reduced by neoadjuvant radiotherapy alone. A previously healthy 69-year-old man was admitted with dysphagia. Initial esophagogastroduodenoscopy (EGD revealed a small nodular polypoid lesion of about 10 mm in the middle esophagus. A second EGD 1 month later showed that the tumor had expanded into a huge mass. A biopsy specimen revealed that the tumor comprised squamous cell carcinoma with spindle cell components, and the tumor was diagnosed as carcinosarcoma which was diagnosed as stage I (T1bN0M0. Due to renal dysfunction, the patient was treated with neoadjuvant radiotherapy (40 Gy without chemotherapy. A third EGD 1 month later revealed remarkable tumor reduction. He then underwent total esophagectomy with regional lymph node dissection (pStage 0, pT1aN0M0. After surgical operation, the patient was followed up without adjuvant therapy. Whole body computed tomography revealed lung metastasis 14 months after surgery, and the patient died 2 months later. The neoadjuvant radiotherapy for esophageal carcinosarcoma was considered to have contributed to the subsequent surgery and his prolonged survival time. Thus, radiotherapy alone might be a suitable neoadjuvant therapy for esophageal carcinosarcomas.

  20. Performance of machinery in potato production in one growing season

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, K.; Jensen, A.L.; Bochtis, D.D.; Sørensen, C.G.

    2015-07-01

    Statistics on the machinery performance are essential for farm managers to make better decisions. In this paper, the performance of all machineries in five sequential operations, namely bed forming, stone separation, planting, spraying and harvesting in the potato production system, were investigated during one growing season. In order to analyse and decompose the recorded GPS data into various time and distance elements for estimation of the machinery performance, an automatic GPS analysis tool was developed. The field efficiency and field capacity were estimated for each operation. Specifically, the measured average field efficiency was 71.3% for bed forming, 68.5% for stone separation, 40.3% for planting, 69.7% for spraying, and 67.4% for harvesting. The measured average field capacities were 1.46 ha/h, 0.53 ha/h, 0.47 ha/h, 10.21 ha/h, 0.51 ha/h, for the bed forming, stone separation, planting, spraying, and harvesting operations, respectively. These results deviate from the corresponding estimations calculated based on norm data from the American Society of Agricultural and Biological Engineers (ASABE). The deviations indicate that norms provided by ASABE cannot be used directly for the prediction of performance of the machinery used in this work. Moreover, the measured data of bed forming and stone separation could be used as supplementary data for the ASABE which does not provide performance norms for these two operations. The gained results can help farm managers to make better management and operational decisions that result in potential improvement in productivity and profitability as well as in potential environmental benefits. (Author)