WorldWideScience

Sample records for largest multimeric enzyme

  1. Radiation inactivation of multimeric enzymes: application to subunit interactions of adenylate cyclase

    International Nuclear Information System (INIS)

    Verkman, A.S.; Skorecki, K.L.; Ausiello, D.A.

    1986-01-01

    Radiation inactivation has been applied extensively to determine the molecular weight of soluble enzyme and receptor systems from the slope of a linear ln (activity) vs. dose curve. Complex nonlinear inactivation curves are predicted for multimeric enzyme systems, composed of distinct subunits in equilibrium with multimeric complexes. For the system A1 + A2----A1A2, with an active A1A2 complex (associative model), the ln (activity) vs. dose curve is linear for high dissociation constant, K. If a monomer, A1, has all the enzyme activity (dissociative model), the ln (activity) vs. dose curve has an activation hump at low radiation dose if the inactive subunit, A2, has a higher molecular weight than A1 and has upward concavity when A2 is smaller than A1. In general, a radiation inactivation model for a multistep mechanism for enzyme activation fulfills the characteristics of an associative or dissociative model if the reaction step forming active enzyme is an associative or dissociative reaction. Target theory gives the molecular weight of the active enzyme subunit or complex from the limiting slope of the ln (activity) vs. dose curve at high radiation dose. If energy transfer occurs among subunits in the multimer, the ln (activity) vs. dose curve is linear for a single active component and is concave upward for two or more active components. The use of radiation inactivation as a method to determine enzyme size and multimeric subunit assembly is discussed with specific application to the hormone-sensitive adenylate cyclase system. It is shown that the complex inactivation curves presented in the accompanying paper can be used select the best mechanism out of a series of seven proposed mechanisms for the activation of adenylate cyclase by hormone

  2. Essential multimeric enzymes in kinetoplastid parasites: A host of potentially druggable protein-protein interactions.

    Science.gov (United States)

    Wachsmuth, Leah M; Johnson, Meredith G; Gavenonis, Jason

    2017-06-01

    Parasitic diseases caused by kinetoplastid parasites of the genera Trypanosoma and Leishmania are an urgent public health crisis in the developing world. These closely related species possess a number of multimeric enzymes in highly conserved pathways involved in vital functions, such as redox homeostasis and nucleotide synthesis. Computational alanine scanning of these protein-protein interfaces has revealed a host of potentially ligandable sites on several established and emerging anti-parasitic drug targets. Analysis of interfaces with multiple clustered hotspots has suggested several potentially inhibitable protein-protein interactions that may have been overlooked by previous large-scale analyses focusing solely on secondary structure. These protein-protein interactions provide a promising lead for the development of new peptide and macrocycle inhibitors of these enzymes.

  3. Multimerization rules for G-quadruplexes

    Czech Academy of Sciences Publication Activity Database

    Kolesnikova, Sofia; Hubálek, Martin; Bednárová, Lucie; Cvačka, Josef; Curtis, Edward A.

    2017-01-01

    Roč. 45, č. 15 (2017), s. 8684-8696 ISSN 0305-1048 Institutional support: RVO:61388963 Keywords : tetramolecular G-quadruplexes * RNA G-quadruplexes * circular dichroism Subject RIV: CE - Biochemistry OBOR OECD: Biochemistry and molecular biology Impact factor: 10.162, year: 2016 https://academic.oup.com/nar/article/45/15/8684/4002725/Multimerization-rules-for-Gquadruplexes

  4. Enzyme

    Science.gov (United States)

    Enzymes are complex proteins that cause a specific chemical change in all parts of the body. For ... use them. Blood clotting is another example of enzymes at work. Enzymes are needed for all body ...

  5. Multimeric, Multifunctional Derivatives of Poly(ethylene glycol

    Directory of Open Access Journals (Sweden)

    Gian Maria Bonora

    2011-07-01

    Full Text Available This article reviews the use of multifunctional polymers founded on high-molecular weight poly(ethylene glycol (PEG. The design of new PEG derivatives assembled in a dendrimer-like multimeric fashion or bearing different functionalities on the same molecule is described. Their use as new drug delivery systems based on the conjugation of multiple copies or diversely active drugs on the same biocompatible support is illustrated.

  6. Multimeric and trimeric subunit SP-D are interconvertible structures with distinct ligand interaction

    DEFF Research Database (Denmark)

    Sørensen, Grith Lykke; Hoegh, Silje V; Leth-Larsen, Rikke

    2009-01-01

    -D compared to Met11 SP-D. Multimerization has proven important for enhancement of microbial phagocytosis. In the present study defined multimeric forms of Met11Thr SP-D were isolated from human amniotic fluid. Implementation of ManNAc-affinity chromatography allowed high recovery of natural trimeric SP......-D multimers. Trimeric SP-D subunits also showed greater binding to endogenous lipoproteins: LDL, oxLDL, and HDL, than multimeric SP-D. In conclusion, purified trimeric and multimeric SP-D represent separate and only partly interconvertible molecular populations with distinct biochemical properties....

  7. Largest College Endowments, 2011

    Science.gov (United States)

    Chronicle of Higher Education, 2012

    2012-01-01

    Of all endowments valued at more than $250-million, the UCLA Foundation had the highest rate of growth over the previous year, at 49 percent. This article presents a table of the largest college endowments in 2011. The table covers the "rank," "institution," "market value as of June 30, 2011," and "1-year change" of institutions participating in…

  8. The ability of multimerized cyclophilin A to restrict retrovirus infection

    International Nuclear Information System (INIS)

    Javanbakht, Hassan; Diaz-Griffero, Felipe; Yuan Wen; Yeung, Darwin F.; Li Xing; Song Byeongwoon; Sodroski, Joseph

    2007-01-01

    In owl monkeys, the typical retroviral restriction factor of primates, TRIM5α, is replaced by TRIMCyp. TRIMCyp consists of the TRIM5 RING, B-box 2 and coiled-coil domains, as well as the intervening linker regions, fused with cyclophilin A. TRIMCyp restricts infection of retroviruses, such as human immunodeficiency virus (HIV-1) and feline immunodeficiency virus (FIV), with capsids that can bind cyclophilin A. The TRIM5 coiled coil promotes the trimerization of TRIMCyp. Here we show that cyclophilin A that is oligomeric as a result of fusion with a heterologous multimer exhibits substantial antiretroviral activity. The addition of the TRIM5 RING, B-box 2 and Linker 2 to oligomeric cyclophilin A generated a protein with antiretroviral activity approaching that of wild-type TRIMCyp. Multimerization increased the binding of cyclophilin A to the HIV-1 capsid, promoting accelerated uncoating of the capsid and restriction of infection

  9. Multimerized CHR-derived peptides as HIV-1 fusion inhibitors.

    Science.gov (United States)

    Nomura, Wataru; Hashimoto, Chie; Suzuki, Takaharu; Ohashi, Nami; Fujino, Masayuki; Murakami, Tsutomu; Yamamoto, Naoki; Tamamura, Hirokazu

    2013-08-01

    To date, several HIV-1 fusion inhibitors based on the carboxy-terminal leucine/isoleucine heptad repeat (CHR) region of an HIV-1 envelope protein gp41 have been discovered. We have shown that a synthetic peptide mimetic of a trimer form of the CHR-derived peptide C34 has potent inhibitory activity against the HIV-1 fusion mechanism, compared to a monomer C34 peptide. The present study revealed that a dimeric form of C34 is evidently structurally critical for fusion inhibitors, and that the activity of multimerized CHR-derived peptides in fusion inhibition is affected by the properties of the unit peptides C34, SC34EK, and T20. The fluorescence-based study suggested that the N36-interactive sites of the C34 trimer, including hydrophobic residues, are exposed outside the trimer and that trimerization of C34 caused a remarkable increase in fusion inhibitory activity. The present results could be useful in the design of fusion inhibitors against viral infections which proceed via membrane fusion with host cells. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. Facile and high-efficient immobilization of histidine-tagged multimeric protein G on magnetic nanoparticles

    Science.gov (United States)

    Lee, Jiho; Chang, Jeong Ho

    2014-12-01

    This work reports the high-efficient and one-step immobilization of multimeric protein G on magnetic nanoparticles. The histidine-tagged (His-tag) recombinant multimeric protein G was overexpressed in Escherichia coli BL21 by the repeated linking of protein G monomers with a flexible linker. High-efficient immobilization on magnetic nanoparticles was demonstrated by two different preparation methods through the amino-silane and chloro-silane functionalization on silica-coated magnetic nanoparticles. Three kinds of multimeric protein G such as His-tag monomer, dimer, and trimer were tested for immobilization efficiency. For these tests, bicinchoninic acid (BCA) assay was employed to determine the amount of immobilized His-tag multimeric protein G. The result showed that the immobilization efficiency of the His-tag multimeric protein G of the monomer, dimer, and trimer was increased with the use of chloro-silane-functionalized magnetic nanoparticles in the range of 98% to 99%, rather than the use of amino-silane-functionalized magnetic nanoparticles in the range of 55% to 77%, respectively.

  11. Surfactant protein D multimerization and gene polymorphism in COPD and asthma

    DEFF Research Database (Denmark)

    Fakih, Dalia; Akiki, Zeina; Junker, Kirsten

    2018-01-01

    BACKGROUND AND OBJECTIVE: A structural single nucleotide polymorphism rs721917 in the surfactant protein D (SP-D) gene, known as Met11Thr, was reported to influence the circulating levels and degree of multimerization of SP-D and was associated with both COPD and atopy in asthma. Moreover, diseas...

  12. Elastin-like polypeptide switches: A design strategy to detect multimeric proteins.

    Science.gov (United States)

    Dhandhukia, Jugal P; Brill, Dab A; Kouhi, Aida; Pastuszka, Martha K; MacKay, J Andrew

    2017-09-01

    Elastin-Like Polypeptides (ELPs) reversibly phase separate in response to changes in temperature, pressure, concentration, pH, and ionic species. While powerful triggers, biological microenvironments present a multitude of more specific biological cues, such as antibodies, cytokines, and cell-surface receptors. To develop better biosensors and bioresponsive drug carriers, rational strategies are required to sense and respond to these target proteins. We recently reported that noncovalent association of two ELP fusion proteins to a "chemical inducer of dimerization" small molecule (1.5 kDa) induces phase separation at physiological temperatures. Having detected a small molecule, here we present the first evidence that ELP multimerization can also detect a much larger (60 kDa) protein target. To demonstrate this strategy, ELPs were biotinylated at their amino terminus and mixed with tetrameric streptavidin. At a stoichiometric ratio of [4:1], two to three biotin-ELPs associate with streptavidin into multimeric complexes with an apparent K d of 5 nM. The increased ELP density around a streptavidin core strongly promotes isothermal phase separation, which was tuned to occur at physiological temperature. This phase separation reverses upon saturation with excess streptavidin, which only favors [1:1] complexes. Together, these findings suggest that ELP association with multimeric biomolecules is a viable strategy to deliberately engineer ELPs that respond to multimeric protein substrates. © 2017 The Protein Society.

  13. Oxidative stress/damage induces multimerization and interaction of Fanconi anemia proteins.

    Science.gov (United States)

    Park, Su-Jung; Ciccone, Samantha L M; Beck, Brian D; Hwang, Byounghoon; Freie, Brian; Clapp, D Wade; Lee, Suk-Hee

    2004-07-16

    Fanconi anemia (FANC) is a heterogeneous genetic disorder characterized by a hypersensitivity to DNA-damaging agents, chromosomal instability, and defective DNA repair. Eight FANC genes have been identified so far, and five of them (FANCA, -C, -E, -F, and -G) assemble in a multinuclear complex and function at least in part in a complex to activate FANCD2 by monoubiquitination. Here we show that FANCA and FANCG are redox-sensitive proteins that are multimerized and/or form a nuclear complex in response to oxidative stress/damage. Both FANCA and FANCG proteins exist as monomers under non-oxidizing conditions, whereas they become multimers following H2O2 treatment. Treatment of cells with oxidizing agent not only triggers the multimeric complex of FANCA and FANCG in vivo but also induces the interaction between FANCA and FANCG. N-Ethylmaleimide treatment abolishes multimerization and interaction of FANCA and FANCG in vitro. Taken together, our results lead us to conclude that FANCA and FANCG uniquely respond to oxidative damage by forming complex(es) via intermolecular disulfide linkage(s), which may be crucial in forming such complexes and in determining their function.

  14. Largest particle detector nearing completion

    CERN Multimedia

    2006-01-01

    "Construction of another part of the Large Hadron Collider (LHC), the worl's largest particle accelerator at CERN in Switzerland, is nearing completion. The Compact Muon Solenoid (CMS) is oner of the LHC project's four large particle detectors. (1/2 page)

  15. The Bryopsis hypnoides plastid genome: multimeric forms and complete nucleotide sequence.

    Directory of Open Access Journals (Sweden)

    Fang Lü

    Full Text Available BACKGROUND: Bryopsis hypnoides Lamouroux is a siphonous green alga, and its extruded protoplasm can aggregate spontaneously in seawater and develop into mature individuals. The chloroplast of B. hypnoides is the biggest organelle in the cell and shows strong autonomy. To better understand this organelle, we sequenced and analyzed the chloroplast genome of this green alga. PRINCIPAL FINDINGS: A total of 111 functional genes, including 69 potential protein-coding genes, 5 ribosomal RNA genes, and 37 tRNA genes were identified. The genome size (153,429 bp, arrangement, and inverted-repeat (IR-lacking structure of the B. hypnoides chloroplast DNA (cpDNA closely resembles that of Chlorella vulgaris. Furthermore, our cytogenomic investigations using pulsed-field gel electrophoresis (PFGE and southern blotting methods showed that the B. hypnoides cpDNA had multimeric forms, including monomer, dimer, trimer, tetramer, and even higher multimers, which is similar to the higher order organization observed previously for higher plant cpDNA. The relative amounts of the four multimeric cpDNA forms were estimated to be about 1, 1/2, 1/4, and 1/8 based on molecular hybridization analysis. Phylogenetic analyses based on a concatenated alignment of chloroplast protein sequences suggested that B. hypnoides is sister to all Chlorophyceae and this placement received moderate support. CONCLUSION: All of the results suggest that the autonomy of the chloroplasts of B. hypnoides has little to do with the size and gene content of the cpDNA, and the IR-lacking structure of the chloroplasts indirectly demonstrated that the multimeric molecules might result from the random cleavage and fusion of replication intermediates instead of recombinational events.

  16. Enhancement of Muramyldipeptide (MDP) Immunostimulatory Activity by Controlled Multimerization on Dendrimers

    DEFF Research Database (Denmark)

    Sørensen, Nanna Skall; Boas, Ulrik; Heegaard, Peter M. H.

    2011-01-01

    Peptidoglycan is a widespread bacterial PAMP molecule and a powerful initiator of innate immune responses. It consists of repeating units of MDP, which as a monomer is only weakly immunostimulatory. Here, MDP-coupled dendrimers were prepared and investigated for stimulation of pig blood mononuclear...... cells. Compared to monomeric MDP, MDP-dendrimers induced a markedly enhanced production of IL-12 p40, IL-1β and IL-6 and completely down-regulated surface expression of B7 and MHC class II. These results suggest a possible novel strategy based on controlled multimerization of minimal PAMP motifs...... on dendrimers for preparing molecularly defined immunostimulators with predictable bioactivities....

  17. Synthesis and evaluation of novel multimeric neurotensin(8-13) analogs.

    Science.gov (United States)

    Hultsch, Christina; Pawelke, Beate; Bergmann, Ralf; Wuest, Frank

    2006-09-01

    Neurotensin(8-13) is a hexapeptide with subnanomolar affinity to the neurotensin receptor 1 which is expressed with high incidence in several human tumor entities. Thus, radiolabeled neurotensin(8-13) might be used for tumor targeting. However, its application is limited by insufficient metabolic stability. The present study aims at improving metabolic stability by the synthesis of multimeric neurotensin(8-13) derivatives rather than commonly employed chemical modifications of the peptide itself. Thus, different dimeric and tetrameric peptides carrying C- or N-terminal attached neurotensin(8-13) moieties have been synthesized and their binding affinity toward the neurotensin receptor has been determined. The results demonstrate that branched compounds containing neurotensin(8-13) attached via its C-terminus only show low receptor affinities, whilst derivatives with neurotensin(8-13) attached via the N-terminus show IC50 values in the nanomolar range. Moreover, within the multimeric neurotensin(8-13) derivatives with neurotensin(8-13) attached via the N-terminus an increasing number of branching units lead to higher binding affinities toward the neurotensin receptor.

  18. Fitting multimeric protein complexes into electron microscopy maps using 3D Zernike descriptors.

    Science.gov (United States)

    Esquivel-Rodríguez, Juan; Kihara, Daisuke

    2012-06-14

    A novel computational method for fitting high-resolution structures of multiple proteins into a cryoelectron microscopy map is presented. The method named EMLZerD generates a pool of candidate multiple protein docking conformations of component proteins, which are later compared with a provided electron microscopy (EM) density map to select the ones that fit well into the EM map. The comparison of docking conformations and the EM map is performed using the 3D Zernike descriptor (3DZD), a mathematical series expansion of three-dimensional functions. The 3DZD provides a unified representation of the surface shape of multimeric protein complex models and EM maps, which allows a convenient, fast quantitative comparison of the three-dimensional structural data. Out of 19 multimeric complexes tested, near native complex structures with a root-mean-square deviation of less than 2.5 Å were obtained for 14 cases while medium range resolution structures with correct topology were computed for the additional 5 cases.

  19. A Rhizavidin Monomer with Nearly Multimeric Avidin-Like Binding Stability Against Biotin Conjugates.

    Science.gov (United States)

    Lee, Jeong Min; Kim, Jung A; Yen, Tzu-Chi; Lee, In Hwan; Ahn, Byungjun; Lee, Younghoon; Hsieh, Chia-Lung; Kim, Ho Min; Jung, Yongwon

    2016-03-01

    Developing a monomeric form of an avidin-like protein with highly stable biotin binding properties has been a major challenge in biotin-avidin linking technology. Here we report a monomeric avidin-like protein-enhanced monoavidin-with off-rates almost comparable to those of multimeric avidin proteins against various biotin conjugates. Enhanced monoavidin (eMA) was developed from naturally dimeric rhizavidin by optimally maintaining protein rigidity during monomerization and additionally shielding the bound biotin by diverse engineering of the surface residues. eMA allowed the monovalent and nonperturbing labeling of head-group-biotinylated lipids in bilayer membranes. In addition, we fabricated an unprecedented 24-meric avidin probe by fusing eMA to a multimeric cage protein. The 24-meric avidin and eMA were utilized to demonstrate how artificial clustering of cell-surface proteins greatly enhances the internalization rates of assembled proteins on live cells. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Adipocyte spliced form of X-box-binding protein 1 promotes adiponectin multimerization and systemic glucose homeostasis

    NARCIS (Netherlands)

    Sha, H.; Yang, L.; Liu, M.; Xia, S.; Liu, Y.; Liu, F.; Kersten, A.H.; Qi, L.

    2014-01-01

    The physiological role of the spliced form of X-box–binding protein 1 (XBP1s), a key transcription factor of the endoplasmic reticulum (ER) stress response, in adipose tissue remains largely unknown. In this study, we show that overexpression of XBP1s promotes adiponectin multimerization in

  1. Distinct subcellular trafficking resulting from monomeric vs multimeric targeting to endothelial ICAM-1: implications for drug delivery.

    Science.gov (United States)

    Ghaffarian, Rasa; Muro, Silvia

    2014-12-01

    Ligand-targeted, receptor-mediated endocytosis is commonly exploited for intracellular drug delivery. However, cells-surface receptors may follow distinct endocytic fates when bound by monomeric vs multimeric ligands. Our purpose was to study this paradigm using ICAM-1, an endothelial receptor involved in inflammation, to better understand its regulation and potential for drug delivery. Our procedure involved fluorescence microscopy of human endothelial cells to determine the endocytic behavior of unbound ICAM-1 vs ICAM-1 bound by model ligands: monomeric (anti-ICAM) vs multimeric (anti-ICAM biotin-streptavidin conjugates or anti-ICAM coated onto 100 nm nanocarriers). Our findings suggest that both monomeric and multimeric ligands undergo a similar endocytic pathway sensitive to amiloride (∼50% inhibition), but not inhibitors of clathrin-pits or caveoli. After 30 min, ∼60-70% of both ligands colocalized with Rab11a-compartments. By 3-5 h, ∼65-80% of multimeric anti-ICAM colocalized with perinuclear lysosomes with ∼60-80% degradation, while 70% of monomeric anti-ICAM remained associated with Rab11a at the cell periphery and recycled to and from the cell-surface with minimal (drug delivery.

  2. Conformational changes of the N-terminal part of Mason-Pfizer monkey virus p12 protein during multimerization

    Czech Academy of Sciences Publication Activity Database

    Knejzlík, Z.; Ulbrich, P.; Strohalm, Martin; Laštůvková, H.; Kodíček, M.; Sakalian, M.; Ruml, T.

    2009-01-01

    Roč. 393, č. 1 (2009), s. 168-176 ISSN 0042-6822 Institutional research plan: CEZ:AV0Z50200510 Keywords : alpha-Helix * Multimerization * CD spectroscopy Subject RIV: EE - Microbiology, Virology Impact factor: 3.042, year: 2009

  3. A rolling circle replication mechanism produces multimeric lariats of mitochondrial DNA in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Samantha C Lewis

    2015-02-01

    Full Text Available Mitochondrial DNA (mtDNA encodes respiratory complex subunits essential to almost all eukaryotes; hence respiratory competence requires faithful duplication of this molecule. However, the mechanism(s of its synthesis remain hotly debated. Here we have developed Caenorhabditis elegans as a convenient animal model for the study of metazoan mtDNA synthesis. We demonstrate that C. elegans mtDNA replicates exclusively by a phage-like mechanism, in which multimeric molecules are synthesized from a circular template. In contrast to previous mammalian studies, we found that mtDNA synthesis in the C. elegans gonad produces branched-circular lariat structures with multimeric DNA tails; we were able to detect multimers up to four mtDNA genome unit lengths. Further, we did not detect elongation from a displacement-loop or analogue of 7S DNA, suggesting a clear difference from human mtDNA in regard to the site(s of replication initiation. We also identified cruciform mtDNA species that are sensitive to cleavage by the resolvase RusA; we suggest these four-way junctions may have a role in concatemer-to-monomer resolution. Overall these results indicate that mtDNA synthesis in C. elegans does not conform to any previously documented metazoan mtDNA replication mechanism, but instead are strongly suggestive of rolling circle replication, as employed by bacteriophages. As several components of the metazoan mitochondrial DNA replisome are likely phage-derived, these findings raise the possibility that the rolling circle mtDNA replication mechanism may be ancestral among metazoans.

  4. Vaccination with multimeric recombinant VP28 induces high protection against white spot syndrome virus in shrimp.

    Science.gov (United States)

    Taengchaiyaphum, Suparat; Nakayama, Hideki; Srisala, Jiraporn; Khiev, Ratny; Aldama-Cano, Diva January; Thitamadee, Siripong; Sritunyalucksana, Kallaya

    2017-11-01

    To improve the efficacy of WSSV protection, multimeric (tetrameric) recombinant VP28 (4XrVP28) was produced and tested in comparison with those of monomeric VP28 (1XrVP28). In vitro binding of either 1XrVP28 or 4XrVP28 to shrimp hemocyte surface was evident as early as 10 min after protein inoculation. Similar results were obtained in vivo when shrimp were injected with recombinant proteins that the proteins bound to the hemocyte surface could be detected since 5 min after injection. Comparison of the WSSV protection efficiencies of 1XrVP28 or 4XrVP28 were performed by injection the purified 1XrVP28 or 4XrVP28 (22.5 μg/shrimp) and WSSV inoculum (1000 copies/shrimp) into shrimp. At 10 dpi, while shrimp injected with WSSV inoculum reached 100% mortality, shrimp injected with 1XrVP28 + WSSV or 4XrVP28 + WSSV showed relative percent survival (RPS) of 67% and 81%, respectively. PCR quantification revealed high number of WSSV in the moribund shrimp of WSSV- and 1XrVP28+WSSV-injected group. In contrast, lower number of WSSV copies were found in the survivors both from 1XrVP28+WSSV- or 4XrVP28+WSSV- injected groups. Histopathological analysis demonstrated the WSSV infected lesions found in the moribund from WSSV-infected group and 1XrVP28+WSSV-injected group, but less or none in the survivors. ELISA demonstrated that 4XrVP28 exhibited higher affinity binding to rPmRab7, a WSSV binding protein essential for WSSV entry to the cell than 1XrVP28. Taken together, the protection against WSSV in shrimp could be improved by application of multimeric rVP28. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. TIA-1 Self-Multimerization, Phase Separation, and Recruitment into Stress Granules Are Dynamically Regulated by Zn2+

    Directory of Open Access Journals (Sweden)

    Joseph B. Rayman

    2018-01-01

    Full Text Available Summary: Stress granules are non-membranous structures that transiently form in the cytoplasm during cellular stress, where they promote translational repression of non-essential RNAs and modulate cell signaling by sequestering key signal transduction proteins. These and other functions of stress granules facilitate an adaptive cellular response to environmental adversity. A key component of stress granules is the prion-related RNA-binding protein, T cell intracellular antigen-1 (TIA-1. Here, we report that recombinant TIA-1 undergoes rapid multimerization and phase separation in the presence of divalent zinc, which can be reversed by the zinc chelator, TPEN. Similarly, the formation and maintenance of TIA-1-positive stress granules in arsenite-treated cells are inhibited by TPEN. In addition, Zn2+ is released in cells treated with arsenite, before stress granule formation. These findings suggest that Zn2+ is a physiological ligand of TIA-1, acting as a stress-inducible second messenger to promote multimerization of TIA-1 and subsequent localization into stress granules. : Rayman et al. show that Zn2+ is a stress-inducible second messenger that triggers self-multimerization and phase separation of TIA-1 and regulates dynamic recruitment of TIA-1 into stress granules. This mechanism is part of an adaptive cellular response to environmental adversity. Keywords: TIA-1, TIA1, stress granules, cellular stress, functional prion, phase separation, zinc regulation

  6. Loy Yang A - Australia's largest privatisation

    International Nuclear Information System (INIS)

    Yenckin, C.

    1997-01-01

    The recent A$4,746 million privatisation of the 2000MW Loy Yang A power station and the Loy Yang coal mine by the Victorian Government is Australia's largest privatisation and one of 1997's largest project financing deals. (author)

  7. Nucleic acid binding properties and intermediates of HCV core protein multimerization in Pichia pastoris

    International Nuclear Information System (INIS)

    Acosta-Rivero, Nelson; Rodriguez, Armando; Musacchio, Alexis; Falcon, Viviana; Suarez, Viana M.; Chavez, Liudmila; Morales-Grillo, Juan; Duenas-Carrera, Santiago

    2004-01-01

    Little is known about the in vivo assembly pathway or structure of the hepatitis C virus nucleocapsid. In this work the intermediates of HCcAg multimerization in Pichia pastoris cells and the nucleic acid binding properties of structured nucleocapsid-like particles (NLPs) were studied. Extensive cross-linking was observed for HCcAg after glutaraldehyde treatment. Data suggest that HCcAg exists in dimeric forms probably representing P21-P21, P21-P23, and P23-P23 dimers. In addition, the presence of HCcAg species that might represent trimers and multimers was observed. After sucrose equilibrium density gradient purification and nuclease digestion, NLPs were shown to contain both RNA and DNA molecules. Finally, the analysis by electron microscopy indicated that native NLPs were resistant to nuclease treatment. These results indicated that HCcAg assembles through dimers, trimers, and multimers' intermediates into capsids in P. pastoris cells. Assembly of NLPs in its natural environment might confer stability to these particles by adopting a compact structure

  8. broken magnet highlights largest collider's engineering challenges

    CERN Multimedia

    Inman, Mason

    2007-01-01

    "Even at the world's soon-to-be largest particle accelerator - a device that promises to push the boundaries of physics - scientists need to be mindful of one of the most fundamental laws in the universe: Murphy's Law. (2 pages)

  9. Structural characterization of PTX3 disulfide bond network and its multimeric status in cumulus matrix organization.

    Science.gov (United States)

    Inforzato, Antonio; Rivieccio, Vincenzo; Morreale, Antonio P; Bastone, Antonio; Salustri, Antonietta; Scarchilli, Laura; Verdoliva, Antonio; Vincenti, Silvia; Gallo, Grazia; Chiapparino, Caterina; Pacello, Lucrezia; Nucera, Eleonora; Serlupi-Crescenzi, Ottaviano; Day, Anthony J; Bottazzi, Barbara; Mantovani, Alberto; De Santis, Rita; Salvatori, Giovanni

    2008-04-11

    PTX3 is an acute phase glycoprotein that plays key roles in resistance to certain pathogens and in female fertility. PTX3 exerts its functions by interacting with a number of structurally unrelated molecules, a capacity that is likely to rely on its complex multimeric structure stabilized by interchain disulfide bonds. In this study, PAGE analyses performed under both native and denaturing conditions indicated that human recombinant PTX3 is mainly composed of covalently linked octamers. The network of disulfide bonds supporting this octameric assembly was resolved by mass spectrometry and Cys to Ser site-directed mutagenesis. Here we report that cysteine residues at positions 47, 49, and 103 in the N-terminal domain form three symmetric interchain disulfide bonds stabilizing four protein subunits in a tetrameric arrangement. Additional interchain disulfide bonds formed by the C-terminal domain cysteines Cys(317) and Cys(318) are responsible for linking the PTX3 tetramers into octamers. We also identified three intrachain disulfide bonds within the C-terminal domain that we used as structural constraints to build a new three-dimensional model for this domain. Previously it has been shown that PTX3 is a key component of the cumulus oophorus extracellular matrix, which forms around the oocyte prior to ovulation, because cumuli from PTX3(-/-) mice show defective matrix organization. Recombinant PTX3 is able to restore the normal phenotype ex vivo in cumuli from PTX3(-/-) mice. Here we demonstrate that PTX3 Cys to Ser mutants, mainly assembled into tetramers, exhibited wild type rescue activity, whereas a mutant, predominantly composed of dimers, had impaired functionality. These findings indicate that protein oligomerization is essential for PTX3 activity within the cumulus matrix and implicate PTX3 tetramers as the functional molecular units required for cumulus matrix organization and stabilization.

  10. The surface science of enzymes

    DEFF Research Database (Denmark)

    Rod, Thomas Holm; Nørskov, Jens Kehlet

    2002-01-01

    One of the largest challenges to science in the coming years is to find the relation between enzyme structure and function. Can we predict which reactions an enzyme catalyzes from knowledge of its structure-or from its amino acid sequence? Can we use that knowledge to modify enzyme function......? To solve these problems we must understand in some detail how enzymes interact with reactants from its surroundings. These interactions take place at the surface of the enzyme and the question of enzyme function can be viewed as the surface science of enzymes. In this article we discuss how to describe...... catalysis by enzymes, and in particular the analogies between enzyme catalyzed reactions and surface catalyzed reactions. We do this by discussing two concrete examples of reactions catalyzed both in nature (by enzymes) and in industrial reactors (by inorganic materials), and show that although analogies...

  11. Multimerization of the cytoplasmic domain of syndecan-4 is required for its ability to activate protein kinase C

    DEFF Research Database (Denmark)

    Oh, E S; Woods, A; Couchman, J R

    1997-01-01

    of syndecan-4 (4L) containing a membrane-proximal basic sequence did not form higher order oligomers and could not regulate the activity of PKCalphabetagamma unless induced to aggregate by phosphatidylinositol 4,5-bisphosphate. Oligomerization and PKC regulatory activity of the 4V peptide were both increased...... by addition of N-terminal cysteine and reduced by phosphorylation of the cysteine thiol group. Concentration of syndecan-4 at sites of focal adhesion formation may enhance multimerization and both localize PKC and potentiate its activity to induce stable complex formation....

  12. Total adiponectin and adiponectin multimeric complexes in relation to weight loss-induced improvements in insulin sensitivity in obese women

    DEFF Research Database (Denmark)

    Polak, J.; Kovacova, Z.; Holst, C.

    2008-01-01

    , and LMW). The HMW form was suggested to be closely associated with insulin sensitivity. This study investigated whether diet-induced changes in insulin sensitivity were associated with changes in adiponectin multimeric complexes. SUBJECTS: Twenty obese women with highest and twenty obese women with lowest...... diet induced changes in insulin sensitivity (responders and non-responders respectively), matched for weight loss (body mass index (BMI)=34.5 (s.d. 2.9) resp. 36.5 kg/m(2) (s.d. 4.0) for responders and non-responders), were selected from 292 women who underwent a 10-week low-caloric diet (LCD; 600 kcal...

  13. CERN tests largest superconducting solenoid magnet

    CERN Multimedia

    2006-01-01

    "CERN's Compacts Muon Solenoid (CMS) - the world's largest superconducting solenoid magnet - has reached full field in testing. The instrument is part of the proton-proton Large Hadron Collider (LHC) project, located in a giant subterranean chamber at Cessy on the Franco-Swiss border." (1 page)

  14. TIA-1 Self-Multimerization, Phase Separation, and Recruitment into Stress Granules Are Dynamically Regulated by Zn2.

    Science.gov (United States)

    Rayman, Joseph B; Karl, Kevin A; Kandel, Eric R

    2018-01-02

    Stress granules are non-membranous structures that transiently form in the cytoplasm during cellular stress, where they promote translational repression of non-essential RNAs and modulate cell signaling by sequestering key signal transduction proteins. These and other functions of stress granules facilitate an adaptive cellular response to environmental adversity. A key component of stress granules is the prion-related RNA-binding protein, T cell intracellular antigen-1 (TIA-1). Here, we report that recombinant TIA-1 undergoes rapid multimerization and phase separation in the presence of divalent zinc, which can be reversed by the zinc chelator, TPEN. Similarly, the formation and maintenance of TIA-1-positive stress granules in arsenite-treated cells are inhibited by TPEN. In addition, Zn 2+ is released in cells treated with arsenite, before stress granule formation. These findings suggest that Zn 2+ is a physiological ligand of TIA-1, acting as a stress-inducible second messenger to promote multimerization of TIA-1 and subsequent localization into stress granules. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  15. High-level expression of an antimicrobial peptide histonin as a natural form by multimerization and furin-mediated cleavage.

    Science.gov (United States)

    Kim, Jung Min; Jang, Su A; Yu, Byung Jo; Sung, Bong Hyun; Cho, Ju Hyun; Kim, Sun Chang

    2008-02-01

    Direct expression of an antimicrobial peptide (AMP) in Escherichia coli causes several problems such as the toxicity of AMP to the host cell, its susceptibility to proteolytic degradation, and decreased antimicrobial activity due to the additional residue(s) introduced after cleavage of AMPs from fusion partners. To overcome these problems and produce a large quantity of a potent AMP histonin (RAGLQFPVGKLLKKLLKRLKR) in E. coli, an efficient expression system was developed, in which the toxicity of histonin was neutralized by a fusion partner F4 (a truncated fragment of PurF protein) and the productivity was increased by a multimeric expression of a histonin gene. The expression level of the fusion proteins reached a maximum with a 12-mer of a histonin gene. In addition, because of the RLKR residues present at the C terminus of histonin, furin cleavage of the multimeric histonin expressed produces an intact, natural histonin. The AMP activity of the histonin produced in E. coli was identical to that of a synthetic histonin. With our expression system, 167 mg of histonin was obtained from 1 l of E. coli culture. These results may lead to a cost-effective solution for the mass production of AMPs that are toxic to a host.

  16. Pancreatic Enzymes

    Science.gov (United States)

    ... Contact Us DONATE NOW GENERAL DONATION PURPLESTRIDE Pancreatic enzymes Home Facing Pancreatic Cancer Living with Pancreatic Cancer ... and see a registered dietitian. What are pancreatic enzymes? Pancreatic enzymes help break down fats, proteins and ...

  17. Crash testing the largest experiment on Earth

    OpenAIRE

    Cauchi, Marija

    2015-01-01

    Under Europe lies a 27 km tunnel that is both the coldest and hottest place on Earth. The Large Hadron Collider (LHC) has already found out what gives mass to all the matter in the Universe. It is now trying to go even deeper into what makes up everything we see around us. Dr Marija Cauchi writes about her research that helped protect this atom smasher from itself. Photography by Jean Claude Vancell. http://www.um.edu.mt/think/crash-testing-the-largest-experiment-on-earth/

  18. The world's largest LNG producer's next market

    International Nuclear Information System (INIS)

    Fuller, R.; Isworo Suharno; Simandjuntak, W.M.P.

    1996-01-01

    The development of the domestic gas market in Indonesia, the world's largest liquefied natural gas producing country, is described as part of the overall impact of the country's oil and gas production. The first large scale use of natural gas in Indonesia was established in 1968 when a fertiliser plant using gas as the feedstock was built. Ultimately, through increased yields, this has enabled Indonesia to be self-sufficient in rice and an exporter of fertiliser. Problems which stand in the way of further developments include: capital, though Pertamina and PGN are perceived as attractive for foreign investment; the lack of a regulatory framework for gas; geographical constraints, among them the fact that the gas deposits are remote from the largest population concentrations; lack of infrastructure. There are nevertheless plans for expansion and the provision of an integrated gas pipeline system. Pertamina, which has responsibility for all oil and gas developments, and PGN, whose primary role has been as a manufacturer and distributor of gas, are now working together in the coordination of all gas activities. (10 figures). (UK)

  19. Conformational changes of the N-terminal part of Mason-Pfizer monkey virus p12 protein during multimerization

    International Nuclear Information System (INIS)

    Knejzlik, Zdenek; Ulbrich, Pavel; Strohalm, Martin; Lastuvkova, Hana; Kodicek, Milan; Sakalian, Michael; Ruml, Tomas

    2009-01-01

    The Mason-Pfizer monkey virus is a prototype Betaretrovirus with the defining characteristic that it assembles spherical immature particles from Gag-related polyprotein precursors within the cytoplasm of the infected cell. It was shown previously that the N-terminal part of the Gag p12 domain (wt-Np12) is required for efficient assembly. However, the precise role for p12 in mediating Gag-Gag interaction is still poorly understood. In this study we employed detailed circular dichroism spectroscopy, electron microscopy and ultracentrifugation analyses of recombinant wt-Np12 prepared by in vitro transcription and translation. The wt-Np12 domain fragment forms fibrillar structures in a concentration-dependent manner. Assembly into fibers is linked to a conformational transition from unfolded or another non-periodical state to α-helix during multimerization.

  20. Biogenic manganese oxide nanoparticle formation by a multimeric multicopper oxidase Mnx.

    Science.gov (United States)

    Romano, Christine A; Zhou, Mowei; Song, Yang; Wysocki, Vicki H; Dohnalkova, Alice C; Kovarik, Libor; Paša-Tolić, Ljiljana; Tebo, Bradley M

    2017-09-29

    Bacteria that produce Mn oxides are extraordinarily skilled engineers of nanomaterials that contribute significantly to global biogeochemical cycles. Their enzyme-based reaction mechanisms may be genetically tailored for environmental remediation applications or bioenergy production. However, significant challenges exist for structural characterization of the enzymes responsible for biomineralization. The active Mn oxidase in Bacillus sp. PL-12, Mnx, is a complex composed of a multicopper oxidase (MCO), MnxG, and two accessory proteins, MnxE and MnxF. MnxG shares sequence similarity with other, structurally characterized MCOs. MnxE and MnxF have no similarity to any characterized proteins. The ~200 kDa complex has been recalcitrant to crystallization, so its structure is unknown. Here, we show that native mass spectrometry defines the subunit topology and copper binding of Mnx, while high-resolution electron microscopy visualizes the protein and nascent Mn oxide minerals. These data provide critical structural information for understanding Mn biomineralization by such unexplored enzymes.Significant challenges exist for structural characterization of enzymes responsible for biomineralization. Here the authors show that native mass spectrometry and high resolution electron microscopy can define the subunit topology and copper binding of a manganese oxidizing complex, and describe early stage formation of its mineral products.

  1. Evolution of the Largest Mammalian Genome.

    Science.gov (United States)

    Evans, Ben J; Upham, Nathan S; Golding, Goeffrey B; Ojeda, Ricardo A; Ojeda, Agustina A

    2017-06-01

    The genome of the red vizcacha rat (Rodentia, Octodontidae, Tympanoctomys barrerae) is the largest of all mammals, and about double the size of their close relative, the mountain vizcacha rat Octomys mimax, even though the lineages that gave rise to these species diverged from each other only about 5 Ma. The mechanism for this rapid genome expansion is controversial, and hypothesized to be a consequence of whole genome duplication or accumulation of repetitive elements. To test these alternative but nonexclusive hypotheses, we gathered and evaluated evidence from whole transcriptome and whole genome sequences of T. barrerae and O. mimax. We recovered support for genome expansion due to accumulation of a diverse assemblage of repetitive elements, which represent about one half and one fifth of the genomes of T. barrerae and O. mimax, respectively, but we found no strong signal of whole genome duplication. In both species, repetitive sequences were rare in transcribed regions as compared with the rest of the genome, and mostly had no close match to annotated repetitive sequences from other rodents. These findings raise new questions about the genomic dynamics of these repetitive elements, their connection to widespread chromosomal fissions that occurred in the T. barrerae ancestor, and their fitness effects-including during the evolution of hypersaline dietary tolerance in T. barrerae. ©The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  2. Canada's largest co-gen project

    International Nuclear Information System (INIS)

    Salaff, S.

    2000-01-01

    In November 2000, the TransAlta Energy Corp. began construction on its $400 million natural gas fuelled cogeneration project in Sarnia Ontario. The Sarnia Regional Cogeneration Project (SRCP) is designed to integrate a new 440 MW cogeneration facility to be built at the Sarnia Division of Dow Chemicals Canada Inc. with nearby existing generators totaling 210 MW at Dow and Bayer Inc. At 650 MW, the new facility will rank as Canada's largest cogeneration installation. Commercial operation is scheduled for October 2002. TransAlta owns three natural gas fuelled cogeneration facilities in Ontario (in Ottawa, Mississauga and Windsor) totaling 250 MW. The cost of electric power in Ontario is currently controlled by rising natural gas prices and the supply demand imbalance. This balance will be significantly affected by the possible return to service of 2000 MW of nuclear generating capacity. The SRCP project was announced just prior to the Ontario Energy Competition Act of October 1998 which committed the province to introduce competition to the electricity sector and which created major uncertainties in the electricity market. Some of the small, 25 MW projects which survived the market uncertainty included the Toronto-based Toromont Energy Ltd. project involving gas fuelled cogeneration and methane gas generation from landfill projects in Sudbury and Waterloo. It was emphasized that cogeneration and combined heat and power projects have significant environmental advantages over large combined cycle facilities. The Ontario Energy Board is currently considering an application from TransAlta to link the SRCP facility to Ontario's Hydro One Network Inc.'s transmission grid. 1 fig

  3. Biogenic manganese oxide nanoparticle formation by a multimeric multicopper oxidase Mnx

    Energy Technology Data Exchange (ETDEWEB)

    Romano, Christine A.; Zhou, Mowei; Song, Yang; Wysocki, Vicki H.; Dohnalkova, Alice C.; Kovarik, Libor; Paša-Tolić, Ljiljana; Tebo, Bradley M.

    2017-09-29

    Bacteria that produce Mn oxides are extraordinarily skilled engineers of nanomaterials that contribute significantly to global biogeochemical cycles. Their enzyme-based reaction mechanisms may be genetically tailored for environmental remediation applications or bioenergy production. However, significant challenges exist for structural characterization of the enzymes responsible for biomineralization. The active Mn oxidase, Mnx, in Bacillus sp. PL-12 is a complex composed of a multicopper oxidase (MCO), MnxG, and two accessory proteins MnxE and MnxF. MnxG shares sequence similarity with other, structurally characterized MCOs. However, MnxE and MnxF have no similarity to any characterized proteins. The ~200 kDa complex has been recalcitrant to crystallization, so its structure is unknown. In this study, native mass spectrometry defines the subunit topology and copper binding of the Mnx complex, while high resolution electron microscopy visualizes the protein and nascent Mn oxide minerals. These data provide critical structural information for conceptualizing how Mnx produces nanoparticulate Mn oxides.

  4. Enzyme Informatics

    Science.gov (United States)

    Alderson, Rosanna G.; Ferrari, Luna De; Mavridis, Lazaros; McDonagh, James L.; Mitchell, John B. O.; Nath, Neetika

    2012-01-01

    Over the last 50 years, sequencing, structural biology and bioinformatics have completely revolutionised biomolecular science, with millions of sequences and tens of thousands of three dimensional structures becoming available. The bioinformatics of enzymes is well served by, mostly free, online databases. BRENDA describes the chemistry, substrate specificity, kinetics, preparation and biological sources of enzymes, while KEGG is valuable for understanding enzymes and metabolic pathways. EzCatDB, SFLD and MACiE are key repositories for data on the chemical mechanisms by which enzymes operate. At the current rate of genome sequencing and manual annotation, human curation will never finish the functional annotation of the ever-expanding list of known enzymes. Hence there is an increasing need for automated annotation, though it is not yet widespread for enzyme data. In contrast, functional ontologies such as the Gene Ontology already profit from automation. Despite our growing understanding of enzyme structure and dynamics, we are only beginning to be able to design novel enzymes. One can now begin to trace the functional evolution of enzymes using phylogenetics. The ability of enzymes to perform secondary functions, albeit relatively inefficiently, gives clues as to how enzyme function evolves. Substrate promiscuity in enzymes is one example of imperfect specificity in protein-ligand interactions. Similarly, most drugs bind to more than one protein target. This may sometimes result in helpful polypharmacology as a drug modulates plural targets, but also often leads to adverse side-effects. Many cheminformatics approaches can be used to model the interactions between druglike molecules and proteins in silico. We can even use quantum chemical techniques like DFT and QM/MM to compute the structural and energetic course of enzyme catalysed chemical reaction mechanisms, including a full description of bond making and breaking. PMID:23116471

  5. Capsid protein VP4 of human rhinovirus induces membrane permeability by the formation of a size-selective multimeric pore.

    Directory of Open Access Journals (Sweden)

    Anusha Panjwani

    2014-08-01

    Full Text Available Non-enveloped viruses must deliver their viral genome across a cell membrane without the advantage of membrane fusion. The mechanisms used to achieve this remain poorly understood. Human rhinovirus, a frequent cause of the common cold, is a non-enveloped virus of the picornavirus family, which includes other significant pathogens such as poliovirus and foot-and-mouth disease virus. During picornavirus cell entry, the small myristoylated capsid protein VP4 is released from the virus, interacts with the cell membrane and is implicated in the delivery of the viral RNA genome into the cytoplasm to initiate replication. In this study, we have produced recombinant C-terminal histidine-tagged human rhinovirus VP4 and shown it can induce membrane permeability in liposome model membranes. Dextran size-exclusion studies, chemical crosslinking and electron microscopy demonstrated that VP4 forms a multimeric membrane pore, with a channel size consistent with transfer of the single-stranded RNA genome. The membrane permeability induced by recombinant VP4 was influenced by pH and was comparable to permeability induced by infectious virions. These findings present a molecular mechanism for the involvement of VP4 in cell entry and provide a model system which will facilitate exploration of VP4 as a novel antiviral target for the picornavirus family.

  6. Significant role of PB1 and UBA domains in multimerization of Joka2, a selective autophagy cargo receptor from tobacco

    Directory of Open Access Journals (Sweden)

    Katarzyna eZientara-Rytter

    2014-01-01

    Full Text Available Tobacco Joka2 protein is a hybrid homolog of two mammalian selective autophagy cargo receptors, p62 and NBR1. These proteins can directly interact with the members of ATG8 family and the polyubiquitinated cargoes designed for degradation. Function of the selective autophagy cargo receptors relies on their ability to form protein aggregates. It has been shown that the N-terminal PB1 domain of p62 is involved in formation of aggregates, while the UBA domains of p62 and NBR1 have been associated mainly with cargo binding. Here we focus on roles of PB1 and UBA domains in localization and aggregation of Joka2 in plant cells. We show that Joka2 can homodimerize not only through its N-terminal PB1-PB1 interactions but also via interaction between N-terminal PB1 and C-terminal UBA domains. We also demonstrate that Joka2 co-localizes with recombinant ubiquitin and sequestrates it into aggregates and that C-terminal part (containing UBA domains is sufficient for this effect. Our results indicate that Joka2 accumulates in cytoplasmic aggregates and suggest that in addition to these multimeric forms it also exists in the nucleus and cytoplasm in a monomeric form.

  7. Functional Sites Induce Long-Range Evolutionary Constraints in Enzymes.

    Directory of Open Access Journals (Sweden)

    Benjamin R Jack

    2016-05-01

    Full Text Available Functional residues in proteins tend to be highly conserved over evolutionary time. However, to what extent functional sites impose evolutionary constraints on nearby or even more distant residues is not known. Here, we report pervasive conservation gradients toward catalytic residues in a dataset of 524 distinct enzymes: evolutionary conservation decreases approximately linearly with increasing distance to the nearest catalytic residue in the protein structure. This trend encompasses, on average, 80% of the residues in any enzyme, and it is independent of known structural constraints on protein evolution such as residue packing or solvent accessibility. Further, the trend exists in both monomeric and multimeric enzymes and irrespective of enzyme size and/or location of the active site in the enzyme structure. By contrast, sites in protein-protein interfaces, unlike catalytic residues, are only weakly conserved and induce only minor rate gradients. In aggregate, these observations show that functional sites, and in particular catalytic residues, induce long-range evolutionary constraints in enzymes.

  8. Crystal structure of B acillus anthracis virulence regulator AtxA and effects of phosphorylated histidines on multimerization and activity: AtxA multimerization, phosphorylation and activity

    Energy Technology Data Exchange (ETDEWEB)

    Hammerstrom, Troy G.; Lori, Horton B.; Swick, Michelle C.; Joachimiak, Andrzej; Osipiuk, Jerzy; Koehler, Theresa M.

    2014-12-30

    The Bacillus anthracis virulence regulator AtxA controls transcription of the anthrax toxin genes and capsule biosynthetic operon. AtxA activity is elevated during growth in media containing glucose and CO2/bicarbonate, and there is a positive correlation between the CO2/bicarbonate signal, AtxA activity and homomultimerization. AtxA activity is also affected by phosphorylation at specific histidines. We show that AtxA crystallizes as a dimer. Distinct folds associated with predicted DNA-binding domains (HTH1 and HTH2) and phosphoenolpyruvate: carbohydrate phosphotransferase system-regulated domains (PRD1 and PRD2) are apparent. We tested AtxA variants containing single and double phosphomimetic (HisAsp) and phosphoablative (HisAla) amino acid changes for activity in B.anthracis cultures and for protein-protein interactions in cell lysates. Reduced activity of AtxA H199A, lack of multimerization and activity of AtxAH379D variants, and predicted structural changes associated with phosphorylation support a model for control of AtxA function. We propose that (i) in the AtxA dimer, phosphorylation of H199 in PRD1 affects HTH2 positioning, influencing DNA-binding; and (ii) phosphorylation of H379 in PRD2 disrupts dimer formation. The AtxA structure is the first reported high-resolution full-length structure of a PRD-containing regulator, and can serve as a model for proteins of this family, especially those that link virulence to bacterial metabolism.

  9. Crystal structure of Bacillus anthracis virulence regulator AtxA and effects of phosphorylated histidines on multimerization and activity.

    Science.gov (United States)

    Hammerstrom, Troy G; Horton, Lori B; Swick, Michelle C; Joachimiak, Andrzej; Osipiuk, Jerzy; Koehler, Theresa M

    2015-02-01

    The Bacillus anthracis virulence regulator AtxA controls transcription of the anthrax toxin genes and capsule biosynthetic operon. AtxA activity is elevated during growth in media containing glucose and CO(2)/bicarbonate, and there is a positive correlation between the CO(2)/bicarbonate signal, AtxA activity and homomultimerization. AtxA activity is also affected by phosphorylation at specific histidines. We show that AtxA crystallizes as a dimer. Distinct folds associated with predicted DNA-binding domains (HTH1 and HTH2) and phosphoenolpyruvate: carbohydrate phosphotransferase system-regulated domains (PRD1 and PRD2) are apparent. We tested AtxA variants containing single and double phosphomimetic (His→Asp) and phosphoablative (His→Ala) amino acid changes for activity in B. anthracis cultures and for protein-protein interactions in cell lysates. Reduced activity of AtxA H199A, lack of multimerization and activity of AtxAH379D variants, and predicted structural changes associated with phosphorylation support a model for control of AtxA function. We propose that (i) in the AtxA dimer, phosphorylation of H199 in PRD1 affects HTH2 positioning, influencing DNA-binding; and (ii) phosphorylation of H379 in PRD2 disrupts dimer formation. The AtxA structure is the first reported high-resolution full-length structure of a PRD-containing regulator, and can serve as a model for proteins of this family, especially those that link virulence to bacterial metabolism. © 2014 John Wiley & Sons Ltd.

  10. Essential roles of insulin, AMPK signaling and lysyl and prolyl hydroxylases in the biosynthesis and multimerization of adiponectin.

    Science.gov (United States)

    Zhang, Lin; Li, Ming-Ming; Corcoran, Marie; Zhang, Shaoping; Cooper, Garth J S

    2015-01-05

    Post-translational modifications (PTMs) of the adiponectin molecule are essential for its full bioactivity, and defects in PTMs leading to its defective production and multimerization have been linked to the mechanisms of insulin resistance, obesity, and type-2 diabetes. Here we observed that, in differentiated 3T3-L1 adipocytes, decreased insulin signaling caused by blocking of insulin receptors (InsR) with an anti-InsR blocking antibody, increased rates of adiponectin secretion, whereas concomitant elevations in insulin levels counteracted this effect. Adenosine monophosphate-activated protein kinase (AMPK) signaling regulated adiponectin production by modulating the expression of adiponectin receptors, the secretion of adiponectin, and eventually the expression of adiponectin itself. We found that lysyl hydroxylases (LHs) and prolyl hydroxylases (PHs) were expressed in white-adipose tissue of ob/ob mice, wherein LH3 levels were increased compared with controls. In differentiated 3T3-L1 adipocytes, both non-specific inhibition of LHs and PHs by dipyridyl, and specific inhibition of LHs by minoxidil and of P4H with ethyl-3,4-dihydroxybenzoate, caused significant suppression of adiponectin production, more particularly of the higher-order isoforms. Transient gene knock-down of LH3 (Plod3) caused a suppressive effect, especially on the high molecular-weight (HMW) isoforms. These data indicate that PHs and LHs are both required for physiological adiponectin production and in particular are essential for the formation/secretion of the HMW isoforms. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  11. Schizosaccharomyces pombe Rad22A and Rad22B have similar biochemical properties and form multimeric structures

    Energy Technology Data Exchange (ETDEWEB)

    Vries, Femke A.T. de [Department of Toxicogenetics, Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden (Netherlands); Zonneveld, Jose B.M. [Department of Toxicogenetics, Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden (Netherlands); Groot, Anton J. de [Department of Toxicogenetics, Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden (Netherlands); Koning, Roman I. [Department of Molecular Cell Biology, Leiden University Medical Center, Leiden (Netherlands); Zeeland, Albert A. van [Department of Toxicogenetics, Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden (Netherlands); Pastink, Albert [Department of Toxicogenetics, Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden (Netherlands)]. E-mail: A.Pastink@lumc.nl

    2007-02-03

    The Saccharomyces cerevisiae Rad52 protein has a crucial role in the repair of DNA double-strand breaks by homologous recombination. In vitro, Rad52 displays DNA binding and strand annealing activities and promotes Rad51-mediated strand exchange. Schizosaccharomyces pombe has two Rad52 homologues, Rad22A and Rad22B. Whereas rad22A deficient strains exhibit severe defects in repair and recombination, rad22B mutants have a much less severe phenotype. To better understand the role of Rad22A and Rad22B in double-strand break repair, both proteins were purified to near homogeneity. Using gel retardation and filter binding assays, binding of Rad22A and Rad22B to short single-stranded DNAs was demonstrated. Binding of Rad22A to double-stranded oligonucleotides or linearized plasmid molecules containing blunt ends or short single-stranded overhangs could not be detected. Rad22B also does not bind efficiently to short duplex oligonucleotides but binds readily to DNA fragments containing 3'-overhangs. Rad22A as well as Rad22B efficiently promote annealing of complementary single-stranded DNAs. In the presence of Rad22A annealing of complementary DNAs is almost 90%. Whereas in reactions containing Rad22B the maximum level of annealing is 60%, most likely due to inhibition of the reaction by duplex DNA. Gel-filtration experiments and electron microscopic analyses indicate self-association of Rad22A and Rad22B and the formation of multimeric structures as has been observed for Rad52 in yeast and man.

  12. Identification of a probable pore-forming domain in the multimeric vacuolar anion channel AtALMT9.

    Science.gov (United States)

    Zhang, Jingbo; Baetz, Ulrike; Krügel, Undine; Martinoia, Enrico; De Angeli, Alexis

    2013-10-01

    Aluminum-activated malate transporters (ALMTs) form an important family of anion channels involved in fundamental physiological processes in plants. Because of their importance, the role of ALMTs in plant physiology is studied extensively. In contrast, the structural basis of their functional properties is largely unknown. This lack of information limits the understanding of the functional and physiological differences between ALMTs and their impact on anion transport in plants. This study aimed at investigating the structural organization of the transmembrane domain of the Arabidopsis (Arabidopsis thaliana) vacuolar channel AtALMT9. For that purpose, we performed a large-scale mutagenesis analysis and found two residues that form a salt bridge between the first and second putative transmembrane α-helices (TMα1 and TMα2). Furthermore, using a combination of pharmacological and mutagenesis approaches, we identified citrate as an "open channel blocker" of AtALMT9 and used this tool to examine the inhibition sensitivity of different point mutants of highly conserved amino acid residues. By this means, we found a stretch within the cytosolic moiety of the TMα5 that is a probable pore-forming domain. Moreover, using a citrate-insensitive AtALMT9 mutant and biochemical approaches, we could demonstrate that AtALMT9 forms a multimeric complex that is supposedly composed of four subunits. In summary, our data provide, to our knowledge, the first evidence about the structural organization of an ion channel of the ALMT family. We suggest that AtALMT9 is a tetramer and that the TMα5 domains of the subunits contribute to form the pore of this anion channel.

  13. Guaranteeing uptime at worl's largest particle physics lab

    CERN Multimedia

    Brodkin, Jon

    2007-01-01

    "As the European agency CERN was gearing up to build the world's largest particle accelerator, officials there knew they could not afford to have problems in their technical infrastructure cause any downtime." (1 page)

  14. Monomeric, dimeric and multimeric system of RGD peptides radiolabeled with 177Lu for tumors therapy that expressing αβ integrin s

    International Nuclear Information System (INIS)

    Luna G, M. A.

    2014-01-01

    The conjugation of peptides to gold nanoparticles (AuNPs) produces biocompatible and stable multimeric systems with target-specific molecular recognition. Peptides based on the cyclic Arg-Gly-Asp (RGD) sequence have been reported as high affinity agents for the α(v)β(3) and α(v)β(5) integrin. The aim of this research was to prepare a multimeric system of 177 Lu-labeled gold nanoparticles conjugated to c[RGDfK(C)] [cyclo(Arg-Gly-Asp-Phe-Lys(Cys)] peptides and to compare the radiation absorbed dose with that of 177 Lu-labeled monomeric and dimeric RGD peptides to α(v)β(3) integrin-positive U87MG tumors in mice, as well as, evaluate the in vitro potential 177 Lu-AuNP-c[RGDfK(C)] as a plasmonic photothermal therapy and targeted radiotherapy system in MCF7 breast cancer cells. DOTA-GGC (1,4,7,10-tetraaza cyclododecane-N,N,N-tetraacetic-Gly-Gly-Cys) and c[RGDfK(C)] peptides were synthesized and conjugated to AuNPs by the spontaneous reaction of the thiol groups. Tem, UV-Vis, XP S, Raman and Far-IR spectroscopy techniques demonstrated that AuNPs were functionalized with the peptides. To obtain 177 Lu-AuNP-c[RGDfK(C)], the 177 Lu-DOTA-GGC radio peptide was first prepared and added to a solution of AuNPs followed by c[RGDfK(C)] (25 μL, 5 μM) at 18 grades C for 15 min. 177 Lu-DOTA-GGC, 177 Lu- DOTA-cRGDfK and 177 Lu-DOTA-E-c(RGDfK) 2 were prepared by adding 177 LuCl 3 (370 MBq) to 5 μL (1 mg/ml) of the DOTA derivative diluted with 50 μL of 1 M acetate buffer at ph 5. The mixture was incubated at 90 grades C in a block heater for 30 min. Radiochemical purity was determined by ultrafiltration and HPLC analyses. After laser irradiation, the presence of c[RGDfK(C)]-AuNP in cells caused a significant increase in the temperature of the medium (50.5 grades C, compared to 40.3 grades C without AuNPs) resulting in a significant decrease in MCF7 cell viability down to 9 %. After treatment with 177 Lu-AuNP-c[RGDfK(C)], the MCF7 cell proliferation was significantly inhibited

  15. Joint Asymptotic Distributions of Smallest and Largest Insurance Claims

    Directory of Open Access Journals (Sweden)

    Hansjörg Albrecher

    2014-07-01

    Full Text Available Assume that claims in a portfolio of insurance contracts are described by independent and identically distributed random variables with regularly varying tails and occur according to a near mixed Poisson process. We provide a collection of results pertaining to the joint asymptotic Laplace transforms of the normalised sums of the smallest and largest claims, when the length of the considered time interval tends to infinity. The results crucially depend on the value of the tail index of the claim distribution, as well as on the number of largest claims under consideration.

  16. Challenges with the largest commercial hydrogen station in the world

    Energy Technology Data Exchange (ETDEWEB)

    Charbonneau, Thomas; Gauthier, Pierre [Air Liquide Canada (Canada)

    2010-07-01

    This abstract's objective is to share with the participants the story of the largest hydrogen fueling station made to this date and to kick-start the story, we will cover the challenges; first the technical ones; the operational ones; the distribution ones and; the financial ones. We will then move on to review the logistic (geographic) issues raised by the project and conclude our presentation by sharing the output values of the largest fueling station built so far in the world. (orig.)

  17. NAFTA: The World's Largest Trading Zone Turns 20

    Science.gov (United States)

    Ferrarini, Tawni Hunt; Day, Stephen

    2014-01-01

    Everyone under the age of 20 who has grown up in North America has lived in the common market created by NAFTA--the North American Free Trade Agreement. In a zone linking the United States, Canada, and Mexico, most goods and investments flow freely across borders to users, consumers, and investors. In 1994, NAFTA created the largest relatively…

  18. Synchrotron Emission on the Largest Scales: Radio Detection of the ...

    Indian Academy of Sciences (India)

    Abstract. Shocks and turbulence generated during large-scale structure formation are predicted to produce large-scale, low surface-brightness synchrotron emission. On the largest scales, this emission is globally correlated with the thermal baryon distribution, and constitutes the 'syn- chrotron cosmic-web'. I present the ...

  19. Building Earth's Largest Library: Driving into the Future.

    Science.gov (United States)

    Coffman, Steve

    1999-01-01

    Examines the Amazon.com online bookstore as a blueprint for designing the world's largest library. Topics include selection; accessibility and convenience; quality of Web sites and search tools; personalized service; library collection development, including interlibrary loan; library catalogs and catalog records; a circulation system; costs;…

  20. Analysis of Human Standing Balance by Largest Lyapunov Exponent

    Directory of Open Access Journals (Sweden)

    Kun Liu

    2015-01-01

    Full Text Available The purpose of this research is to analyse the relationship between nonlinear dynamic character and individuals’ standing balance by the largest Lyapunov exponent, which is regarded as a metric for assessing standing balance. According to previous study, the largest Lyapunov exponent from centre of pressure time series could not well quantify the human balance ability. In this research, two improvements were made. Firstly, an external stimulus was applied to feet in the form of continuous horizontal sinusoidal motion by a moving platform. Secondly, a multiaccelerometer subsystem was adopted. Twenty healthy volunteers participated in this experiment. A new metric, coordinated largest Lyapunov exponent was proposed, which reflected the relationship of body segments by integrating multidimensional largest Lyapunov exponent values. By using this metric in actual standing performance under sinusoidal stimulus, an obvious relationship between the new metric and the actual balance ability was found in the majority of the subjects. These results show that the sinusoidal stimulus can make human balance characteristics more obvious, which is beneficial to assess balance, and balance is determined by the ability of coordinating all body segments.

  1. Worlds largest particle physics laboratory selects Proxim Wireless Mesh

    CERN Multimedia

    2007-01-01

    "Proxim Wireless has announced that the European Organization for Nuclear Research (CERN), the world's largest particle physics laboratory and the birthplace of the World Wide Web, is using it's ORiNOCO AP-4000 mesh access points to extend the range of the laboratory's Wi-Fi network and to provide continuous monitoring of the lab's calorimeters" (1/2 page)

  2. PNNL supercomputer to become largest computing resource on the Grid

    CERN Multimedia

    2002-01-01

    Hewlett Packard announced that the US DOE Pacific Northwest National Laboratory will connect a 9.3-teraflop HP supercomputer to the DOE Science Grid. This will be the largest supercomputer attached to a computer grid anywhere in the world (1 page).

  3. Toward sustainable harvesting of Africa's largest medicinal plant ...

    African Journals Online (AJOL)

    Global demand for treating prostate disorders with Prunus africana bark extract has made P. africana Africa's largest medicinal plant export. Unsustainable harvesting practices can lead to local extirpations of this multipurpose tree. Survey research targeting P. africana harvesters in a Tanzania forest reserve revealed that ...

  4. Temporal properties of seismicity and largest earthquakes in SE Carpathians

    Directory of Open Access Journals (Sweden)

    S. Byrdina

    2006-01-01

    Full Text Available In order to estimate the hazard rate distribution of the largest seismic events in Vrancea, South-Eastern Carpathians, we study temporal properties of historical and instrumental catalogues of seismicity. First, on the basis of Generalized Extreme Value theory we estimate the average return period of the largest events. Then, following Bak et al. (2002 and Corral (2005a, we study scaling properties of recurrence times between earthquakes in appropriate spatial volumes. We come to the conclusion that the seismicity is temporally clustered, and that the distribution of recurrence times is significantly different from a Poisson process even for times largely exceeding corresponding periods of foreshock and aftershock activity. Modeling the recurrence times by a gamma distributed variable, we finally estimate hazard rates with respect to the time elapsed from the last large earthquake.

  5. Worlds Largest Wave Energy Project 2007 in Wales

    DEFF Research Database (Denmark)

    Christensen, Lars; Friis-Madsen, Erik; Kofoed, Jens Peter

    2006-01-01

    This paper introduces world largest wave energy project being developed in Wales and based on one of the leading wave energy technologies. The background for the development of wave energy, the total resource ands its distribution around the world is described. In contrast to wind energy turbines...... Dragon has to be scaled in accordance with the wave climate at the deployment site, which makes the Welch demonstrator device the worlds largest WEC so far with a total width of 300 meters. The project budget, the construction methods and the deployment site are also given....... a large number of fundamentally different technologies are utilised to harvest wave energy. The Wave Dragon belongs to the wave overtopping class of converters and the paper describes the fundamentals and the technical solutions used in this wave energy converter. An offshore floating WEC like the Wave...

  6. Upgrade and modernization of the six largest HPPs in Macedonia

    International Nuclear Information System (INIS)

    Hadzievska, M.

    2002-01-01

    In 1998, Electric Power Company of Macedonia and the International Bank for Development and Reconstruction, started the Power System Improvement Project a part of which is the Project for rehabilitation of the six largest Hydro Power Plants (HPPs) in the Republic of Macedonia. The six largest Hydro Power Plants (HPP Vrutok, HPP Raven, HPP Globocica, HPP Tikves and HPP Spilje and HPP Vrben) represent 91% of the country's hydropower capacity. The rehabilitation program is divided in five parts (contracts) and covers the refurbishment of: turbine runners, turbine and generator bearings, governors, inlet valves; butterfly valves, including accessories and control systems; generators, excitation system and voltage regulation; control system, protection and LV auxiliaries; switch gears and control gears in 220 kV, 110 kV and 35 kV substations. At the moment, only the implementation of switch gears has started, the first phase is already finished, and 50 % of the rehabilitation works for HPP Vrutok, the largest HPP, has been finished. With the realization of this project, greater hydropower production is expected. It also expected that HPPs will become a more vital part of the Macedonian power system

  7. Kabob report. Pt. 3. Chevron plant largest in Canada

    Energy Technology Data Exchange (ETDEWEB)

    1971-01-18

    Canada's largest fully integrated primary natural- gas processing and sulfur recovery plant is heading for physical completion by mid-summer of 1971. The Ralph M. Parsons Construction Co. of Canada Ltd., contractor for the S. Kaybob Beaverhill Lake Unit No. 3 gas-processing plant, to be operated by Chevron Standard Ltd., estimates completion by June 30. After that the $80 million complex will have tests and running in time. With any reasonable luck, it should be fully on stream by late summer. Preliminary construction on the 200-acre site started in Jan. 1969 with clearing and contouring of the main plant and sulfur storage sites. Initial rough grading started in the early summer, after spring breakup was over. Delivery of most of the big items was made by rail because the local secondary roads were inadequate for them. Concrete has been a large item. The contractor has its own batch plant on the site for the estimated 28,000 cu yd which will be needed for the whole job. Dominating the construction site from the start has been the high sulfur plant stack, first of the major items to be finished. It will serve to dispose of effluent from the largest sulfur recovery unit in Canada. It is 465 ft high, one of the largest in Alberta, and a significant contribution to pollution control and environmental protection.

  8. Mutational analyses of the core domain of Avian Leukemia and Sarcoma Viruses integrase: critical residues for concerted integration and multimerization

    International Nuclear Information System (INIS)

    Moreau, Karen; Faure, Claudine; Violot, Sebastien; Gouet, Patrice; Verdier, Gerard; Ronfort, Corinne

    2004-01-01

    During replicative cycle of retroviruses, the reverse-transcribed viral DNA is integrated into the cell DNA by the viral integrase (IN) enzyme. The central core domain of IN contains the catalytic site of the enzyme and is involved in binding viral ends and cell DNA as well as dimerization. We previously performed single amino acid substitutions in the core domain of an Avian Leukemia and Sarcoma Virus (ALSV) IN [Arch. Virol. 147 (2002) 1761]. Here, we modeled the resulting IN mutants and analyzed the ability of these mutants to mediate concerted DNA integration in an in vitro assay, and to form dimers by protein-protein cross-linking and size exclusion chromatography. The N197C mutation resulted in the inability of the mutant to perform concerted integration that was concomitant with a loss of IN dimerization. Surprisingly, mutations Q102G and A106V at the dimer interface resulted in mutants with higher efficiencies than the wild-type IN in performing two-ended concerted integration of viral DNA ends. The G139D and A195V mutants had a trend to perform one-ended DNA integration of viral ends instead of two-ended integration. More drastically, the I88L and L135G mutants preferentially mediated nonconcerted DNA integration although the proteins form dimers. Therefore, these mutations may alter the formation of IN complexes of higher molecular size than a dimer that would be required for concerted integration. This study points to the important role of core domain residues in the concerted integration of viral DNA ends as well as in the oligomerization of the enzyme

  9. The Environmental Responsibility of the World’s Largest Banks

    Directory of Open Access Journals (Sweden)

    Ryszawska Bożena

    2018-03-01

    Full Text Available Sustainability transition is changing the role and function of banks, specially their products and services also in relation to stakeholders. Banks are one of the main actors supporting the transition to sustainable economy. The purpose of this study is to emphasise the role of world’s largest banks in that process. Banks are slowly responding to the new demand of sustainability and responsibility, and they try to align with it. The paper is based on an overview of the world’s five largest banks that employ corporate social responsibility (CSR reporting standards, together with detailed enumeration of pro-environmental activities included in the reports. The first section of this paper presents the most popular approaches to the problem at hand, as reported in professional literature. Section two presents the characteristics of the CSR actions in banks. The third section discusses the environmental actions of the biggest banks in Global Reporting Initiative (GRI reporting the most popular standard for reporting non-financial information. And the last part of the paper presents the conclusions resulting from the article. The research was conducted using a variety of sources, such as scientific articles, statistical data, CSR reports of the world’s largest banks, as well reporting principles and standard disclosures. The basic method used in the process of writing was a critical analysis of literature and reports concerning the CSR reporting standards, environmental responsibilities of different kinds of entities, as well as own observations based on special reports of banks. In the article, also the analysis of financial market data, induction method and comparison method have been used. The main conclusions of the analysis of the CSR reports disclosed by the world’s largest banks confirm all three of the theses presented in the article. The findings suggest that the banks under study can be regarded as environmentally responsible

  10. Longevity in Calumma parsonii, the World's largest chameleon.

    Science.gov (United States)

    Tessa, Giulia; Glaw, Frank; Andreone, Franco

    2017-03-01

    Large body size of ectothermic species can be correlated with high life expectancy. We assessed the longevity of the World's largest chameleon, the Parson's chameleon Calumma parsonii from Madagascar by using skeletochronology of phalanges taken from preserved specimens held in European natural history museums. Due to the high bone resorption we can provide only the minimum age of each specimen. The highest minimum age detected was nine years for a male and eight years for a female, confirming that this species is considerably long living among chameleons. Our data also show a strong correlation between snout-vent length and estimated age. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Environmental isotope signatures of the largest freshwater lake in Kerala

    International Nuclear Information System (INIS)

    Unnikrishnan Warrier, C.

    2007-01-01

    Sasthamkotta lake, the largest freshwater lake in Kerala, serves as a source for drinking water for more than half a million people. Environmental 137 Cs analysis done on undisturbed sediment core samples reveals that the recent rate of sedimentation is not uniform in the lake. The useful life of lake is estimated as about 800 years. The δD and δ 18 O values of the lake waters indicate that the lake is well mixed with a slight variation horizontally. The stable isotope studies on well waters from the catchment indicate hydraulic communication with the lake and lake groundwater system is flow-through type. Analytical model also supports this view. (author)

  12. Enzyme detection by microfluidics

    DEFF Research Database (Denmark)

    2013-01-01

    Microfluidic-implemented methods of detecting an enzyme, in particular a DNA-modifying enzyme, are provided, as well as methods for detecting a cell, or a microorganism expressing said enzyme. The enzyme is detected by providing a nucleic acid substrate, which is specifically targeted...... by that enzyme...

  13. Fishing down the largest coral reef fish species.

    Science.gov (United States)

    Fenner, Douglas

    2014-07-15

    Studies on remote, uninhabited, near-pristine reefs have revealed surprisingly large populations of large reef fish. Locations such as the northwestern Hawaiian Islands, northern Marianas Islands, Line Islands, U.S. remote Pacific Islands, Cocos-Keeling Atoll and Chagos archipelago have much higher reef fish biomass than islands and reefs near people. Much of the high biomass of most remote reef fish communities lies in the largest species, such as sharks, bumphead parrots, giant trevally, and humphead wrasse. Some, such as sharks and giant trevally, are apex predators, but others such as bumphead parrots and humphead wrasse, are not. At many locations, decreases in large reef fish species have been attributed to fishing. Fishing is well known to remove the largest fish first, and a quantitative measure of vulnerability to fishing indicates that large reef fish species are much more vulnerable to fishing than small fish. The removal of large reef fish by fishing parallels the extinction of terrestrial megafauna by early humans. However large reef fish have great value for various ecological roles and for reef tourism. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Elevated Liver Enzymes

    Science.gov (United States)

    Symptoms Elevated liver enzymes By Mayo Clinic Staff Elevated liver enzymes may indicate inflammation or damage to cells in the liver. Inflamed or ... than normal amounts of certain chemicals, including liver enzymes, into the bloodstream, which can result in elevated ...

  15. Carbon and energy fluxes from China's largest freshwater lake

    Science.gov (United States)

    Gan, G.; LIU, Y.

    2017-12-01

    Carbon and energy fluxes between lakes and the atmosphere are important aspects of hydrology, limnology, and ecology studies. China's largest freshwater lake, the Poyang lake experiences tremendous water-land transitions periodically throughout the year, which provides natural experimental settings for the study of carbon and energy fluxes. In this study, we use the eddy covariance technique to explore the seasonal and diurnal variation patterns of sensible and latent heat fluxes of Poyang lake during its high-water and low-water periods, when the lake is covered by water and mudflat, respectively. We also determine the annual NEE of Poyang lake and the variations of NEE's components: Gross Primary Productivity (GPP) and Ecosystem Respiration (Re). Controlling factors of seasonal and diurnal variations of carbon and energy fluxes are analyzed, and land cover impacts on the variation patterns are also studied. Finally, the coupling between the carbon and energy fluxes are analyzed under different atmospheric, boundary stability and land cover conditions.

  16. SSC RIAR is the largest centre of research reactors

    International Nuclear Information System (INIS)

    Kalygin, V.V.

    1997-01-01

    The State Scientific Centre (SSC) ''Research Institute of Atomic Reactors'' (RIAR) is situated 100 km to the south-east from Moscow, in Dimitrovgrad, the Volga Region of the Russian Federation. SSC RIAR is the largest centre of research reactors in Russia. At present there are 5 types of reactor facilities in operation, including two NPP. One of the main tasks the Centre is the investigations on safety increase for power reactors. Broad international connections are available at the Institute. On the basis of the SSC RIAR during 3 years work has been done on the development of the branch training centre (TC) for the training of operation personnel of research and pilot reactors in Russia. (author). 3 tabs

  17. BALU: Largest autoclave research facility in the world

    Directory of Open Access Journals (Sweden)

    Hakan Ucan

    2016-03-01

    Full Text Available Among the large-scale facilities operated at the Center for Lightweight-Production-Technology of the German Aerospace Center in Stade BALU is the world's largest research autoclave. With a loading length of 20m and a loading diameter of 5.8 m the main objective of the facility is the optimization of the curing process operated by components made of carbon fiber on an industrial scale. For this reason, a novel dynamic autoclaving control has been developed that is characterized by peripheral devices to expend the performance of the facility for differential applications, by sensing systems to detect the component state throughout the curing process and by a feedback system, which is capable to intervene into the running autoclave process.

  18. Switzerland's largest wood-pellet factory in Balsthal

    International Nuclear Information System (INIS)

    Stohler, F.

    2004-01-01

    This article describes how a small Swiss electricity utility has broken out of its traditional role in power generation and the distribution of electricity and gone into the production of wood pellets. The pellets, which are made from waste wood (sawdust) available from wood processing companies, are produced on a large scale in one of Europe's largest pellets production facilities. The boom in the use of wood pellets for heating purposes is discussed. The article discusses this unusual approach for a Swiss power utility, which also operates a wood-fired power station and is even involved in an incineration plant for household wastes. The markets being aimed for in Switzerland and in Europe are described, including modern low-energy-consumption housing projects. A further project is described that is to use waste wood available from a large wood processing facility planned in the utility's own region

  19. Opportunities for biodiversity gains under the world's largest reforestation programme

    Science.gov (United States)

    Hua, Fangyuan; Wang, Xiaoyang; Zheng, Xinlei; Fisher, Brendan; Wang, Lin; Zhu, Jianguo; Tang, Ya; Yu, Douglas W.; Wilcove, David S.

    2016-01-01

    Reforestation is a critical means of addressing the environmental and social problems of deforestation. China's Grain-for-Green Program (GFGP) is the world's largest reforestation scheme. Here we provide the first nationwide assessment of the tree composition of GFGP forests and the first combined ecological and economic study aimed at understanding GFGP's biodiversity implications. Across China, GFGP forests are overwhelmingly monocultures or compositionally simple mixed forests. Focusing on birds and bees in Sichuan Province, we find that GFGP reforestation results in modest gains (via mixed forest) and losses (via monocultures) of bird diversity, along with major losses of bee diversity. Moreover, all current modes of GFGP reforestation fall short of restoring biodiversity to levels approximating native forests. However, even within existing modes of reforestation, GFGP can achieve greater biodiversity gains by promoting mixed forests over monocultures; doing so is unlikely to entail major opportunity costs or pose unforeseen economic risks to households. PMID:27598524

  20. SSC RIAR is the largest centre of research reactors

    Energy Technology Data Exchange (ETDEWEB)

    Kalygin, V V [State Scientific Centre, Research Inst. of Atomic Reactors (Russian Federation)

    1997-10-01

    The State Scientific Centre (SSC) ``Research Institute of Atomic Reactors`` (RIAR) is situated 100 km to the south-east from Moscow, in Dimitrovgrad, the Volga Region of the Russian Federation. SSC RIAR is the largest centre of research reactors in Russia. At present there are 5 types of reactor facilities in operation, including two NPP. One of the main tasks the Centre is the investigations on safety increase for power reactors. Broad international connections are available at the Institute. On the basis of the SSC RIAR during 3 years work has been done on the development of the branch training centre (TC) for the training of operation personnel of research and pilot reactors in Russia. (author). 3 tabs.

  1. The largest Silurian vertebrate and its palaeoecological implications

    Science.gov (United States)

    Choo, Brian; Zhu, Min; Zhao, Wenjin; Jia, Liaotao; Zhu, You'an

    2014-01-01

    An apparent absence of Silurian fishes more than half-a-metre in length has been viewed as evidence that gnathostomes were restricted in size and diversity prior to the Devonian. Here we describe the largest pre-Devonian vertebrate (Megamastax amblyodus gen. et sp. nov.), a predatory marine osteichthyan from the Silurian Kuanti Formation (late Ludlow, ~423 million years ago) of Yunnan, China, with an estimated length of about 1 meter. The unusual dentition of the new form suggests a durophagous diet which, combined with its large size, indicates a considerable degree of trophic specialisation among early osteichthyans. The lack of large Silurian vertebrates has recently been used as constraint in palaeoatmospheric modelling, with purported lower oxygen levels imposing a physiological size limit. Regardless of the exact causal relationship between oxygen availability and evolutionary success, this finding refutes the assumption that pre-Emsian vertebrates were restricted to small body sizes. PMID:24921626

  2. Largest US oil and gas fields, August 1993

    International Nuclear Information System (INIS)

    1993-01-01

    The Largest US Oil and Gas Fields is a technical report and part of an Energy Information Administration (EIA) series presenting distributions of US crude oil and natural gas resources, developed using field-level data collected by EIA's annual survey of oil and gas proved reserves. The series' objective is to provide useful information beyond that routinely presented in the EIA annual report on crude oil and natural gas reserves. These special reports also will provide oil and gas resource analysts with a fuller understanding of the nature of US crude oil and natural gas occurrence, both at the macro level and with respect to the specific subjects addressed. The series' approach is to integrate EIA's crude oil and natural gas survey data with related data obtained from other authoritative sources, and then to present illustrations and analyses of interest to a broad spectrum of energy information users ranging from the general public to oil and gas industry personnel

  3. The largest glitch observed in the Crab pulsar

    Science.gov (United States)

    Shaw, B.; Lyne, A. G.; Stappers, B. W.; Weltevrede, P.; Bassa, C. G.; Lien, A. Y.; Mickaliger, M. B.; Breton, R. P.; Jordan, C. A.; Keith, M. J.; Krimm, H. A.

    2018-05-01

    We have observed a large glitch in the Crab pulsar (PSR B0531+21). The glitch occurred around MJD 58064 (2017 November 8) when the pulsar underwent an increase in the rotation rate of Δν = 1.530 × 10-5 Hz, corresponding to a fractional increase of Δν/ν = 0.516 × 10-6 making this event the largest glitch ever observed in this source. Due to our high-cadence and long-dwell time observations of the Crab pulsar we are able to partially resolve a fraction of the total spin-up of the star. This delayed spin-up occurred over a timescale of ˜1.7 days and is similar to the behaviour seen in the 1989 and 1996 large Crab pulsar glitches. The spin-down rate also increased at the glitch epoch by Δ \\dot{ν } / \\dot{ν } = 7 × 10^{-3}. In addition to being the largest such event observed in the Crab, the glitch occurred after the longest period of glitch inactivity since at least 1984 and we discuss a possible relationship between glitch size and waiting time. No changes to the shape of the pulse profile were observed near the glitch epoch at 610 MHz or 1520 MHz, nor did we identify any changes in the X-ray flux from the pulsar. The long-term recovery from the glitch continues to progress as \\dot{ν } slowly rises towards pre-glitch values. In line with other large Crab glitches, we expect there to be a persistent change to \\dot{ν }. We continue to monitor the long-term recovery with frequent, high quality observations.

  4. Oceans of Opportunity. Harnessing Europe's largest domestic energy resource

    International Nuclear Information System (INIS)

    Fichaux, N.; Wilkes, J.

    2009-09-01

    Europe's offshore wind potential is enormous and able to power Europe seven times over. Over 100 GW of offshore wind projects are already in various stages of planning. If realised, these projects would produce 10% of the EU's electricity whilst avoiding 200 million tonnes of CO2 emissions each year. EWEA has a target of 40 GW of offshore wind in the EU by 2020, implying an average annual market growth of 28% over the coming 12 years. The EU market for onshore wind grew by an average 32% per year in the 12-year period from 1992-2004 - what the wind energy industry has achieved on land can be repeated at sea. EWEA's proposed offshore grid builds on the 11 offshore grids currently operating and 21 offshore grids currently being considered by the grid operators in the Baltic and North Seas to give Europe a truly pan-European electricity super highway. Strong political support and action from Europe's policy-makers will allow a new, multi-billion euro industry to be built. This new industry will deliver thousands of green collar jobs and a new renewable energy economy and establish Europe as world leader in offshore wind power technology. A single European electricity market with large amounts of wind power will bring affordable electricity to consumers, reduce import dependence, cut CO2 emissions and allow Europe to access its largest domestic energy source.

  5. Characterization of the largest effector gene cluster of Ustilago maydis.

    Directory of Open Access Journals (Sweden)

    Thomas Brefort

    2014-07-01

    Full Text Available In the genome of the biotrophic plant pathogen Ustilago maydis, many of the genes coding for secreted protein effectors modulating virulence are arranged in gene clusters. The vast majority of these genes encode novel proteins whose expression is coupled to plant colonization. The largest of these gene clusters, cluster 19A, encodes 24 secreted effectors. Deletion of the entire cluster results in severe attenuation of virulence. Here we present the functional analysis of this genomic region. We show that a 19A deletion mutant behaves like an endophyte, i.e. is still able to colonize plants and complete the infection cycle. However, tumors, the most conspicuous symptoms of maize smut disease, are only rarely formed and fungal biomass in infected tissue is significantly reduced. The generation and analysis of strains carrying sub-deletions identified several genes significantly contributing to tumor formation after seedling infection. Another of the effectors could be linked specifically to anthocyanin induction in the infected tissue. As the individual contributions of these genes to tumor formation were small, we studied the response of maize plants to the whole cluster mutant as well as to several individual mutants by array analysis. This revealed distinct plant responses, demonstrating that the respective effectors have discrete plant targets. We propose that the analysis of plant responses to effector mutant strains that lack a strong virulence phenotype may be a general way to visualize differences in effector function.

  6. El Paso natural gas nearing completion of system's largest expansion

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    El Paso Natural Gas Co.'s largest expansion program in its 64-year history will be completed along its northern system this spring or early summer. According to the company, the three-tiered, $241.5 million expansion program will increase El Paso's gas-transport capacity by 835 MMcfd to 2.5 bcfd of conventional and coal-seam gas from the San Juan basin in northwestern New Mexico. That's enough natural gas, says the company, to supply the needs of a city of more than 800,000 residents. This paper reports that the expansion involves the San Juan Triangle system, the company's northern main line, and the Permian-San Juan crossover line. The company also filed with the Federal Energy Regulatory Commission (FERC) in October 1991 to construct a new $15.2 million compressor station, Rio Vista, south of Bloomfield, N.M. The station would be used to move additional gas to the main line

  7. Benchmark Testing of the Largest Titanium Aluminide Sheet Subelement Conducted

    Science.gov (United States)

    Bartolotta, Paul A.; Krause, David L.

    2000-01-01

    To evaluate wrought titanium aluminide (gamma TiAl) as a viable candidate material for the High-Speed Civil Transport (HSCT) exhaust nozzle, an international team led by the NASA Glenn Research Center at Lewis Field successfully fabricated and tested the largest gamma TiAl sheet structure ever manufactured. The gamma TiAl sheet structure, a 56-percent subscale divergent flap subelement, was fabricated for benchmark testing in three-point bending. Overall, the subelement was 84-cm (33-in.) long by 13-cm (5-in.) wide by 8-cm (3-in.) deep. Incorporated into the subelement were features that might be used in the fabrication of a full-scale divergent flap. These features include the use of: (1) gamma TiAl shear clips to join together sections of corrugations, (2) multiple gamma TiAl face sheets, (3) double hot-formed gamma TiAl corrugations, and (4) brazed joints. The structural integrity of the gamma TiAl sheet subelement was evaluated by conducting a room-temperature three-point static bend test.

  8. Largest US oil and gas fields, August 1993

    Energy Technology Data Exchange (ETDEWEB)

    1993-08-06

    The Largest US Oil and Gas Fields is a technical report and part of an Energy Information Administration (EIA) series presenting distributions of US crude oil and natural gas resources, developed using field-level data collected by EIA`s annual survey of oil and gas proved reserves. The series` objective is to provide useful information beyond that routinely presented in the EIA annual report on crude oil and natural gas reserves. These special reports also will provide oil and gas resource analysts with a fuller understanding of the nature of US crude oil and natural gas occurrence, both at the macro level and with respect to the specific subjects addressed. The series` approach is to integrate EIA`s crude oil and natural gas survey data with related data obtained from other authoritative sources, and then to present illustrations and analyses of interest to a broad spectrum of energy information users ranging from the general public to oil and gas industry personnel.

  9. Phosphorus Loadings to the World's Largest Lakes: Sources and Trends

    Science.gov (United States)

    Fink, Gabriel; Alcamo, Joseph; Flörke, Martina; Reder, Klara

    2018-04-01

    Eutrophication is a major water quality issue in lakes worldwide and is principally caused by the loadings of phosphorus from catchment areas. It follows that to develop strategies to mitigate eutrophication, we must have a good understanding of the amount, sources, and trends of phosphorus pollution. This paper provides the first consistent and harmonious estimates of current phosphorus loadings to the world's largest 100 lakes, along with the sources of these loadings and their trends. These estimates provide a perspective on the extent of lake eutrophication worldwide, as well as potential input to the evaluation and management of eutrophication in these lakes. We take a modeling approach and apply the WorldQual model for these estimates. The advantage of this approach is that it allows us to fill in large gaps in observational data. From the analysis, we find that about 66 of the 100 lakes are located in developing countries and their catchments have a much larger average phosphorus yield than the lake catchments in developed countries (11.1 versus 0.7 kg TP km-2 year-1). Second, the main source of phosphorus to the examined lakes is inorganic fertilizer (47% of total). Third, between 2005-2010 and 1990-1994, phosphorus pollution increased at 50 out of 100 lakes. Sixty percent of lakes with increasing pollution are in developing countries. P pollution changed primarily due to changing P fertilizer use. In conclusion, we show that the risk of P-stimulated eutrophication is higher in developing countries.

  10. LHC : The World's Largest Vacuum Systems being commissioned at CERN

    CERN Document Server

    Jiménez, J M

    2008-01-01

    When it switches on in 2008, the 26.7 km Large Hadron Collider (LHC) at CERN, will have the world's largest vacuum system operating over a wide range of pressures and employing an impressive array of vacuum technologies. This system is composed by 54 km of UHV vacuum for the circulating beams and 50 km of insulation vacuum around the cryogenic magnets and the liquid helium transfer lines. Over the 54 km of UHV beam vacuum, 48 km of this are at cryogenic temperature (1.9 K). The remaining 6 km of beam vacuum containing the insertions for "cleaning" the proton beams, radiofrequency cavities for accelerating the protons as well as beam-monitoring equipment is at ambient temperature and uses non-evaporable getter (NEG) coatings - a vacuum technology that was born and industrialized at CERN. The pumping scheme is completed using 780 ion pumps to remove noble gases and to provide pressure interlocks to the 303 vacuum safety valves. Pressure readings are provided by 170 Bayard-Alpert gauges and 1084 gauges (Pirani a...

  11. When clusters collide: constraints on antimatter on the largest scales

    International Nuclear Information System (INIS)

    Steigman, Gary

    2008-01-01

    Observations have ruled out the presence of significant amounts of antimatter in the Universe on scales ranging from the solar system, to the Galaxy, to groups and clusters of galaxies, and even to distances comparable to the scale of the present horizon. Except for the model-dependent constraints on the largest scales, the most significant upper limits to diffuse antimatter in the Universe are those on the ∼Mpc scale of clusters of galaxies provided by the EGRET upper bounds to annihilation gamma rays from galaxy clusters whose intracluster gas is revealed through its x-ray emission. On the scale of individual clusters of galaxies the upper bounds to the fraction of mixed matter and antimatter for the 55 clusters from a flux-limited x-ray survey range from 5 × 10 −9 to −6 , strongly suggesting that individual clusters of galaxies are made entirely of matter or of antimatter. X-ray and gamma-ray observations of colliding clusters of galaxies, such as the Bullet Cluster, permit these constraints to be extended to even larger scales. If the observations of the Bullet Cluster, where the upper bound to the antimatter fraction is found to be −6 , can be generalized to other colliding clusters of galaxies, cosmologically significant amounts of antimatter will be excluded on scales of order ∼20 Mpc (M∼5×10 15 M sun )

  12. Expression of lignocellulolytic enzymes in Pichia pastoris

    Directory of Open Access Journals (Sweden)

    Mellitzer Andrea

    2012-05-01

    Full Text Available Abstract Background Sustainable utilization of plant biomass as renewable source for fuels and chemical building blocks requires a complex mixture of diverse enzymes, including hydrolases which comprise the largest class of lignocellulolytic enzymes. These enzymes need to be available in large amounts at a low price to allow sustainable and economic biotechnological processes. Over the past years Pichia pastoris has become an attractive host for the cost-efficient production and engineering of heterologous (eukaryotic proteins due to several advantages. Results In this paper codon optimized genes and synthetic alcohol oxidase 1 promoter variants were used to generate Pichia pastoris strains which individually expressed cellobiohydrolase 1, cellobiohydrolase 2 and beta-mannanase from Trichoderma reesei and xylanase A from Thermomyces lanuginosus. For three of these enzymes we could develop strains capable of secreting gram quantities of enzyme per liter in fed-batch cultivations. Additionally, we compared our achieved yields of secreted enzymes and the corresponding activities to literature data. Conclusion In our experiments we could clearly show the importance of gene optimization and strain characterization for successfully improving secretion levels. We also present a basic guideline how to correctly interpret the interplay of promoter strength and gene dosage for a successful improvement of the secretory production of lignocellulolytic enzymes in Pichia pastoris.

  13. Prime-boost vaccination with heterologous live vectors encoding SIV gag and multimeric HIV-1 gp160 protein: efficacy against repeated mucosal R5 clade C SHIV challenges.

    Science.gov (United States)

    Lakhashe, Samir K; Velu, Vijayakumar; Sciaranghella, Gaia; Siddappa, Nagadenahalli B; Dipasquale, Janet M; Hemashettar, Girish; Yoon, John K; Rasmussen, Robert A; Yang, Feng; Lee, Sandra J; Montefiori, David C; Novembre, Francis J; Villinger, François; Amara, Rama Rao; Kahn, Maria; Hu, Shiu-Lok; Li, Sufen; Li, Zhongxia; Frankel, Fred R; Robert-Guroff, Marjorie; Johnson, Welkin E; Lieberman, Judy; Ruprecht, Ruth M

    2011-08-05

    We sought to induce primate immunodeficiency virus-specific cellular and neutralizing antibody (nAb) responses in rhesus macaques (RM) through a bimodal vaccine approach. RM were immunized intragastrically (i.g.) with the live-attenuated Listeria monocytogenes (Lm) vector Lmdd-BdopSIVgag encoding SIVmac239 gag. SIV Gag-specific cellular responses were boosted by intranasal and intratracheal administration of replication-competent adenovirus (Ad5hr-SIVgag) encoding the same gag. To broaden antiviral immunity, the RM were immunized with multimeric HIV clade C (HIV-C) gp160 and HIV Tat. SIV Gag-specific cellular immune responses and HIV-1 nAb developed in some RM. The animals were challenged intrarectally with five low doses of R5 SHIV-1157ipEL-p, encoding a heterologous HIV-C Env (22.1% divergent to the Env immunogen). All five controls became viremic. One out of ten vaccinees was completely protected and another had low peak viremia. Sera from the completely and partially protected RM neutralized the challenge virus > 90%; these RM also had strong SIV Gag-specific proliferation of CD8⁺ T cells. Peak and area under the curve of plasma viremia (during acute phase) among vaccinees was lower than for controls, but did not attain significance. The completely protected RM showed persistently low numbers of the α4β7-expressing CD4⁺ T cells; the latter have been implicated as preferential virus targets in vivo. Thus, vaccine-induced immune responses and relatively lower numbers of potential target cells were associated with protection. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Fat-Specific DsbA-L Overexpression Promotes Adiponectin Multimerization and Protects Mice From Diet-Induced Obesity and Insulin Resistance

    Science.gov (United States)

    Liu, Meilian; Xiang, Ruihua; Wilk, Sarah Ann; Zhang, Ning; Sloane, Lauren B.; Azarnoush, Kian; Zhou, Lijun; Chen, Hongzhi; Xiang, Guangda; Walter, Christi A.; Austad, Steven N.; Musi, Nicolas; DeFronzo, Ralph A.; Asmis, Reto; Scherer, Philipp E.; Dong, Lily Q.; Liu, Feng

    2012-01-01

    The antidiabetic and antiatherosclerotic effects of adiponectin make it a desirable drug target for the treatment of metabolic and cardiovascular diseases. However, the adiponectin-based drug development approach turns out to be difficult due to extremely high serum levels of this adipokine. On the other hand, a significant correlation between adiponectin multimerization and its insulin-sensitizing effects has been demonstrated, suggesting a promising alternative therapeutic strategy. Here we show that transgenic mice overexpressing disulfide bond A oxidoreductase-like protein in fat (fDsbA-L) exhibited increased levels of total and the high-molecular-weight form of adiponectin compared with wild-type (WT) littermates. The fDsbA-L mice also displayed resistance to diet-induced obesity, insulin resistance, and hepatic steatosis compared with WT control mice. The protective effects of DsbA-L overexpression on diet-induced insulin resistance, but not increased body weight and fat cell size, were significantly decreased in adiponectin-deficient fDsbA-L mice (fDsbA-L/Ad−/−). In addition, the fDsbA-L/Ad−/− mice displayed greater activity and energy expenditure compared with adiponectin knockout mice under a high-fat diet. Taken together, our results demonstrate that DsbA-L protects mice from diet-induced obesity and insulin resistance through adiponectin-dependent and independent mechanisms. In addition, upregulation of DsbA-L could be an effective therapeutic approach for the treatment of obesity and its associated metabolic disorders. PMID:22807031

  15. Reach and messages of the world's largest ivory burn.

    Science.gov (United States)

    Braczkowski, Alexander; Holden, Matthew H; O'Bryan, Christopher; Choi, Chi-Yeung; Gan, Xiaojing; Beesley, Nicholas; Gao, Yufang; Allan, James; Tyrrell, Peter; Stiles, Daniel; Brehony, Peadar; Meney, Revocatus; Brink, Henry; Takashina, Nao; Lin, Ming-Ching; Lin, Hsien-Yung; Rust, Niki; Salmo, Severino G; Watson, James Em; Kahumbu, Paula; Maron, Martine; Possingham, Hugh P; Biggs, Duan

    2018-03-01

    Recent increases in ivory poaching have depressed African elephant populations. Successful enforcement has led to ivory being stockpiled. Stockpile destruction is becoming increasingly popular, and most destruction has occurred in the last five years. Ivory destruction is intended to send a strong message against ivory consumption, both in promoting a taboo on ivory use and catalyzing policy change. However, there has been no effort to establish the distribution and extent of media reporting on ivory destruction events globally. We analyze media coverage across eleven important nation states of the largest ivory destruction event in history (Kenya, 30 April 2016). We used a well-accepted online media crawling tool and key language translations to search online and print newspapers. We found most online news on the ivory burn came from the US (81% of articles), while print news was dominated by Kenya (61% of articles). We subjected online articles from five key countries and territories to content analysis and found 86-97% of all online articles reported the burn as a positive conservation action, while between 4-50% discussed ivory burning as having a negative impact on elephant conservation. Most articles discussed law enforcement and trade bans as effective for elephant conservation. There was more relative search interest globally on the 2016 Kenyan ivory burn than any other in five years. Our study is the first attempt to track the spread of media around an ivory burn and is a case study in tracking the effects of a conservation-marketing event. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  16. Genome size analyses of Pucciniales reveal the largest fungal genomes.

    Science.gov (United States)

    Tavares, Sílvia; Ramos, Ana Paula; Pires, Ana Sofia; Azinheira, Helena G; Caldeirinha, Patrícia; Link, Tobias; Abranches, Rita; Silva, Maria do Céu; Voegele, Ralf T; Loureiro, João; Talhinhas, Pedro

    2014-01-01

    Rust fungi (Basidiomycota, Pucciniales) are biotrophic plant pathogens which exhibit diverse complexities in their life cycles and host ranges. The completion of genome sequencing of a few rust fungi has revealed the occurrence of large genomes. Sequencing efforts for other rust fungi have been hampered by uncertainty concerning their genome sizes. Flow cytometry was recently applied to estimate the genome size of a few rust fungi, and confirmed the occurrence of large genomes in this order (averaging 225.3 Mbp, while the average for Basidiomycota was 49.9 Mbp and was 37.7 Mbp for all fungi). In this work, we have used an innovative and simple approach to simultaneously isolate nuclei from the rust and its host plant in order to estimate the genome size of 30 rust species by flow cytometry. Genome sizes varied over 10-fold, from 70 to 893 Mbp, with an average genome size value of 380.2 Mbp. Compared to the genome sizes of over 1800 fungi, Gymnosporangium confusum possesses the largest fungal genome ever reported (893.2 Mbp). Moreover, even the smallest rust genome determined in this study is larger than the vast majority of fungal genomes (94%). The average genome size of the Pucciniales is now of 305.5 Mbp, while the average Basidiomycota genome size has shifted to 70.4 Mbp and the average for all fungi reached 44.2 Mbp. Despite the fact that no correlation could be drawn between the genome sizes, the phylogenomics or the life cycle of rust fungi, it is interesting to note that rusts with Fabaceae hosts present genomes clearly larger than those with Poaceae hosts. Although this study comprises only a small fraction of the more than 7000 rust species described, it seems already evident that the Pucciniales represent a group where genome size expansion could be a common characteristic. This is in sharp contrast to sister taxa, placing this order in a relevant position in fungal genomics research.

  17. GIS learning tool for world's largest earthquakes and their causes

    Science.gov (United States)

    Chatterjee, Moumita

    The objective of this thesis is to increase awareness about earthquakes among people, especially young students by showing the five largest and two most predictable earthquake locations in the world and their plate tectonic settings. This is a geographic based interactive tool which could be used for learning about the cause of great earthquakes in the past and the safest places on the earth in order to avoid direct effect of earthquakes. This approach provides an effective way of learning for the students as it is very user friendly and more aligned to the interests of the younger generation. In this tool the user can click on the various points located on the world map which will open a picture and link to the webpage for that point, showing detailed information of the earthquake history of that place including magnitude of quake, year of past quakes and the plate tectonic settings that made this place earthquake prone. Apart from knowing the earthquake related information students will also be able to customize the tool to suit their needs or interests. Students will be able to add/remove layers, measure distance between any two points on the map, select any place on the map and know more information for that place, create a layer from this set to do a detail analysis, run a query, change display settings, etc. At the end of this tool the user has to go through the earthquake safely guidelines in order to be safe during an earthquake. This tool uses Java as programming language and uses Map Objects Java Edition (MOJO) provided by ESRI. This tool is developed for educational purpose and hence its interface has been kept simple and easy to use so that students can gain maximum knowledge through it instead of having a hard time to install it. There are lots of details to explore which can help more about what a GIS based tool is capable of. Only thing needed to run this tool is latest JAVA edition installed in their machine. This approach makes study more fun and

  18. Enzyme inhibition by iminosugars

    DEFF Research Database (Denmark)

    López, Óscar; Qing, Feng-Ling; Pedersen, Christian Marcus

    2013-01-01

    Imino- and azasugar glycosidase inhibitors display pH dependant inhibition reflecting that both the inhibitor and the enzyme active site have groups that change protonation state with pH. With the enzyme having two acidic groups and the inhibitor one basic group, enzyme-inhibitor complexes...

  19. Watching the Creation of Southern California's Largest Reservoir

    Science.gov (United States)

    2001-01-01

    The new Diamond Valley Lake Reservoir near the city of Hemet in Riverside County is billed as the largest earthworks construction project in U.S.history. Construction began in 1995 and involved 31 million cubic meters of foundation excavation and 84 million cubic meters of embankment construction. This set of MISR images captures the most recent phase in the reservoir's activation. At the upper left is a natural-color view acquired by the instrument's vertical-viewing (nadir) camera on March 14, 2000 (Terra orbit 1273), shortly after the Metropolitan Water District began filling the reservoir with water from the Colorado River and Northern California. Water appears darker than the surrounding land. The image at the upper right was acquired nearly one year later on March 1, 2001 (Terra orbit 6399), and shows a clear increase in the reservoir's water content. When full, the lake will hold nearly a trillion liters of water.According to the Metropolitan Water District, the 7 kilometer x 3 kilometer reservoir nearly doubles Southern California's above-groundwater storage capacity. In addition to routine water management, Diamond Valley Lake is designed to provide protection against drought and a six-month emergency supply in the event of earthquake damage to a major aqueduct. In the face of electrical power shortages, it is also expected to reduce dependence on the pumping of water from northern mountains during the high-demand summer months. An unexpected result of site excavation was the uncovering of mastodon and mammoth skeletons along with bones from extinct species not previously thought to have been indigenous to the area, such as the giant long-horned bison and North American lion. A museum and interpretive center is being built to protect these finds.The lower MISR image, from May 20, 2001 (Terra orbit 7564), is a false-color view combining data from the instrument's 26-degree forward view (displayed as blue) with data from the 26-degree backward view

  20. Drilling the Bushveld Complex- the world's largest layered mafic intrusion

    Science.gov (United States)

    Ashwal, L. D.; Webb, S. J.; Trumbull, R. B.

    2013-12-01

    The fact that surprising new discoveries can be made in layered mafic intrusions (e.g., subtle 100-150 m cyclicity in apparently homogeneous cumulates over 1000s of m) means that we are still in the first-order characterization phase of understanding these objects. Accordingly, we have secured funding from ICDP for a planning workshop to be held in Johannesburg in early 2014, aimed at scientific drilling of the Bushveld Complex, the world's largest layered mafic intrusion. Science objectives include, but are not limited to: 1. Magma chamber processes & melt evolution. How many melts/magmas/mushes were involved, what were their compositions and how did they interact? What, if anything, is missing from the Complex, and where did it go? Did Bushveld magmatism have an effect upon Earth's atmosphere at 2 Ga? 2. Crust-mantle interactions & origin of Bushveld granitoids. Are Bushveld granites & rhyolites crustal melts, differentiates from the mafic magmas or products of immiscibility? How can the evolved isotopic signatures in the mafic rocks (e.g., epsilon Nd to -8) be understood? 3. Origin of ore deposits. What were the relative roles of gravity settling, magma mixing, immiscibility and hydrothermal fluid transport in producing the PGE, Cr and V deposits? We have identified 3 potential drilling targets representing a total of ~12 km of drill core. Exact locations of drill sites are to be discussed at the workshop. Target A- East-Central Bushveld Complex. We propose 3 overlapping 3 km boreholes that will provide the first roof-to-floor continuous coverage of the Rustenburg Layered Suite. These boreholes will represent a curated, internationally available reference collection of Bushveld material for present and future research. Target B- Southeastern Bushveld Complex. We propose a single borehole of ~2 km depth, collared in Rooiberg felsite, and positioned to intersect the Roof Zone, Upper Zone, Main Zone and floor of the Complex. Amongst other things, this site will

  1. Final Status Survey for the Largest Decommissioning Project on Earth

    International Nuclear Information System (INIS)

    Dubiel, R.W.; Miller, J.; Quayle, D.

    2006-01-01

    To assist the United States Department of Energy's (US DOE's) re-industrialization efforts at its gaseous diffusion site in Oak Ridge, Tennessee, known as the East Tennessee Technology Park (ETTP), the US DOE awarded a 6-year Decontamination and Decommissioning (D and D) contract to BNG America (formerly BNFL Inc.) in 1997. The ETTP 3-Building D and D Project included the removal and disposition of the materials and equipment from the K-33, K-31, and K-29 Gaseous Diffusion Plant buildings. The three buildings comprise more than 4.8 million square feet (446,000 square meters) of floor surface area and more than 350 million pounds (148 million kilograms) of hazardous and radioactively contaminated material, making it the largest nuclear D and D project in progress anywhere in the world. The logistical hurdles involved in a project of this scope and magnitude required an extensive amount of Engineering and Health Physics professionals. In order to accomplish the Final Status Survey (FSS) for a project of this scope, the speed and efficiency of automated survey equipment was essential. Surveys of floors, structural steel and ceilings up to 60 feet (18 meters) were required. The FSS had to be expanded to include additional remediation and surveys due to characterization surveys and assumptions regarding the nature and extent of contamination provided by the US DOE. Survey design and technical bases had to consider highly variable constituents; including uranium from depleted to low enrichment, variable levels of Technetium-99 and transuranic nuclides, which were introduced into the cascade during the 1960's when recycled uranium (RU) from Savannah River was re-enriched at the facility. The RU was transported to unexpected locations from leaks in the cascade by complex building ventilation patterns. The primary survey tool used for the post remediation and FSS was the Surface Contamination Monitor (SCM) and the associated Survey Information Management System (SIMS

  2. Optimization of oligomeric enzyme activity in ionic liquids using Rhodotorula glutinis yeast phenylalanine ammonia lyase.

    Science.gov (United States)

    Barron, Christiaan C; Sponagle, Brandon J D; Arivalagan, Pugazhendhi; D'Cunha, Godwin B

    2017-01-01

    Phenylalanine ammonia lyase (E.C.4.3.1.24, PAL) activity of Rhodotorula glutinis yeast has been demonstrated in four commonly used ionic liquids. PAL forward reaction was carried out in 1-butyl-3-methylimidazolium methyl sulfate ([BMIM][MeSO 4 ]), 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF 4 ]), 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF 6 ]) and 1-butyl-3-methylimidazolium lactate ([BMIM][lactate]). Our experiments have revealed that PAL is catalytically active in ionic liquids and the enzyme activity in ([BMIM][PF 6 ]) is comparable to that obtained in aqueous buffer medium. Different conditions were optimized for maximal PAL forward activity including time of incubation (30.0min) L -phenylalanine substrate concentration (30.0mM), nature of buffer (50.0mM Tris-HCl), pH (9.0), temperature (37°C), and speed of agitation (100 rev min -1 ). Under these optimized conditions, about 83% conversion of substrate to product was obtained for the PAL forward reaction that was determined using UV spectroscopy at 290nm. PAL reverse reaction in ([BMIM][PF 6 ]) was determined spectrophotometrically at 520nm; and about 59% substrate conversion was obtained. This data provides further knowledge in enzyme biocatalysis in non-aqueous media, and may be of importance when studying the function of other oligomeric/multimeric proteins and enzymes in ionic liquids. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Kinetic memory based on the enzyme-limited competition.

    Science.gov (United States)

    Hatakeyama, Tetsuhiro S; Kaneko, Kunihiko

    2014-08-01

    Cellular memory, which allows cells to retain information from their environment, is important for a variety of cellular functions, such as adaptation to external stimuli, cell differentiation, and synaptic plasticity. Although posttranslational modifications have received much attention as a source of cellular memory, the mechanisms directing such alterations have not been fully uncovered. It may be possible to embed memory in multiple stable states in dynamical systems governing modifications. However, several experiments on modifications of proteins suggest long-term relaxation depending on experienced external conditions, without explicit switches over multi-stable states. As an alternative to a multistability memory scheme, we propose "kinetic memory" for epigenetic cellular memory, in which memory is stored as a slow-relaxation process far from a stable fixed state. Information from previous environmental exposure is retained as the long-term maintenance of a cellular state, rather than switches over fixed states. To demonstrate this kinetic memory, we study several models in which multimeric proteins undergo catalytic modifications (e.g., phosphorylation and methylation), and find that a slow relaxation process of the modification state, logarithmic in time, appears when the concentration of a catalyst (enzyme) involved in the modification reactions is lower than that of the substrates. Sharp transitions from a normal fast-relaxation phase into this slow-relaxation phase are revealed, and explained by enzyme-limited competition among modification reactions. The slow-relaxation process is confirmed by simulations of several models of catalytic reactions of protein modifications, and it enables the memorization of external stimuli, as its time course depends crucially on the history of the stimuli. This kinetic memory provides novel insight into a broad class of cellular memory and functions. In particular, applications for long-term potentiation are discussed

  4. Alternative Fuels Data Center: America's Largest Home Runs on Biodiesel in

    Science.gov (United States)

    North Carolina America's Largest Home Runs on Biodiesel in North Carolina to someone by E-mail Share Alternative Fuels Data Center: America's Largest Home Runs on Biodiesel in North Carolina on Facebook Tweet about Alternative Fuels Data Center: America's Largest Home Runs on Biodiesel in North

  5. Enzymes for improved biomass conversion

    Science.gov (United States)

    Brunecky, Roman; Himmel, Michael E.

    2016-02-02

    Disclosed herein are enzymes and combinations of the enzymes useful for the hydrolysis of cellulose and the conversion of biomass. Methods of degrading cellulose and biomass using enzymes and cocktails of enzymes are also disclosed.

  6. Immobilized enzymes and cells

    Energy Technology Data Exchange (ETDEWEB)

    Bucke, C; Wiseman, A

    1981-04-04

    This article reviews the current state of the art of enzyme and cell immobilization and suggests advances which might be made during the 1980's. Current uses of immobilized enzymes include the use of glucoamylase in the production of glucose syrups from starch and glucose isomerase in the production of high fructose corn syrup. Possibilities for future uses of immobilized enzymes and cells include the utilization of whey and the production of ethanol.

  7. Profiling the orphan enzymes

    Science.gov (United States)

    2014-01-01

    The emergence of Next Generation Sequencing generates an incredible amount of sequence and great potential for new enzyme discovery. Despite this huge amount of data and the profusion of bioinformatic methods for function prediction, a large part of known enzyme activities is still lacking an associated protein sequence. These particular activities are called “orphan enzymes”. The present review proposes an update of previous surveys on orphan enzymes by mining the current content of public databases. While the percentage of orphan enzyme activities has decreased from 38% to 22% in ten years, there are still more than 1,000 orphans among the 5,000 entries of the Enzyme Commission (EC) classification. Taking into account all the reactions present in metabolic databases, this proportion dramatically increases to reach nearly 50% of orphans and many of them are not associated to a known pathway. We extended our survey to “local orphan enzymes” that are activities which have no representative sequence in a given clade, but have at least one in organisms belonging to other clades. We observe an important bias in Archaea and find that in general more than 30% of the EC activities have incomplete sequence information in at least one superkingdom. To estimate if candidate proteins for local orphans could be retrieved by homology search, we applied a simple strategy based on the PRIAM software and noticed that candidates may be proposed for an important fraction of local orphan enzymes. Finally, by studying relation between protein domains and catalyzed activities, it appears that newly discovered enzymes are mostly associated with already known enzyme domains. Thus, the exploration of the promiscuity and the multifunctional aspect of known enzyme families may solve part of the orphan enzyme issue. We conclude this review with a presentation of recent initiatives in finding proteins for orphan enzymes and in extending the enzyme world by the discovery of new

  8. Research and Application of Marine Microbial Enzymes: Status and Prospects

    Science.gov (United States)

    Zhang, Chen; Kim, Se-Kwon

    2010-01-01

    Over billions of years, the ocean has been regarded as the origin of life on Earth. The ocean includes the largest range of habitats, hosting the most life-forms. Competition amongst microorganisms for space and nutrients in the marine environment is a powerful selective force, which has led to evolution. The evolution prompted the marine microorganisms to generate multifarious enzyme systems to adapt to the complicated marine environments. Therefore, marine microbial enzymes can offer novel biocatalysts with extraordinary properties. This review deals with the research and development work investigating the occurrence and bioprocessing of marine microbial enzymes. PMID:20631875

  9. Robust Control of PEP Formation Rate in the Carbon Fixation Pathway of C4 Plants by a Bi-functional Enzyme

    Directory of Open Access Journals (Sweden)

    Hart Yuval

    2011-10-01

    Full Text Available Abstract Background C4 plants such as corn and sugarcane assimilate atmospheric CO2 into biomass by means of the C4 carbon fixation pathway. We asked how PEP formation rate, a key step in the carbon fixation pathway, might work at a precise rate, regulated by light, despite fluctuations in substrate and enzyme levels constituting and regulating this process. Results We present a putative mechanism for robustness in C4 carbon fixation, involving a key enzyme in the pathway, pyruvate orthophosphate dikinase (PPDK, which is regulated by a bifunctional enzyme, Regulatory Protein (RP. The robust mechanism is based on avidity of the bifunctional enzyme RP to its multimeric substrate PPDK, and on a product-inhibition feedback loop that couples the system output to the activity of the bifunctional regulator. The model provides an explanation for several unusual biochemical characteristics of the system and predicts that the system's output, phosphoenolpyruvate (PEP formation rate, is insensitive to fluctuations in enzyme levels (PPDK and RP, substrate levels (ATP and pyruvate and the catalytic rate of PPDK, while remaining sensitive to the system's input (light levels. Conclusions The presented PPDK mechanism is a new way to achieve robustness using product inhibition as a feedback loop on a bifunctional regulatory enzyme. This mechanism exhibits robustness to protein and metabolite levels as well as to catalytic rate changes. At the same time, the output of the system remains tuned to input levels.

  10. Artificial Enzymes, "Chemzymes"

    DEFF Research Database (Denmark)

    Bjerre, Jeannette; Rousseau, Cyril Andre Raphaël; Pedersen, Lavinia Georgeta M

    2008-01-01

    Enzymes have fascinated scientists since their discovery and, over some decades, one aim in organic chemistry has been the creation of molecules that mimic the active sites of enzymes and promote catalysis. Nevertheless, even today, there are relatively few examples of enzyme models that successf......Enzymes have fascinated scientists since their discovery and, over some decades, one aim in organic chemistry has been the creation of molecules that mimic the active sites of enzymes and promote catalysis. Nevertheless, even today, there are relatively few examples of enzyme models...... that successfully perform Michaelis-Menten catalysis under enzymatic conditions (i.e., aqueous medium, neutral pH, ambient temperature) and for those that do, very high rate accelerations are seldomly seen. This review will provide a brief summary of the recent developments in artificial enzymes, so called...... "Chemzymes", based on cyclodextrins and other molecules. Only the chemzymes that have shown enzyme-like activity that has been quantified by different methods will be mentioned. This review will summarize the work done in the field of artificial glycosidases, oxidases, epoxidases, and esterases, as well...

  11. Magnetically responsive enzyme powders

    Energy Technology Data Exchange (ETDEWEB)

    Pospiskova, Kristyna, E-mail: kristyna.pospiskova@upol.cz [Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Safarik, Ivo, E-mail: ivosaf@yahoo.com [Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Department of Nanobiotechnology, Institute of Nanobiology and Structural Biology of GCRC, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic)

    2015-04-15

    Powdered enzymes were transformed into their insoluble magnetic derivatives retaining their catalytic activity. Enzyme powders (e.g., trypsin and lipase) were suspended in various liquid media not allowing their solubilization (e.g., saturated ammonium sulfate and highly concentrated polyethylene glycol solutions, ethanol, methanol, 2-propanol) and subsequently cross-linked with glutaraldehyde. Magnetic modification was successfully performed at low temperature in a freezer (−20 °C) using magnetic iron oxides nano- and microparticles prepared by microwave-assisted synthesis from ferrous sulfate. Magnetized cross-linked enzyme powders were stable at least for two months in water suspension without leakage of fixed magnetic particles. Operational stability of magnetically responsive enzymes during eight repeated reaction cycles was generally without loss of enzyme activity. Separation of magnetically modified cross-linked powdered enzymes from reaction mixtures was significantly simplified due to their magnetic properties. - Highlights: • Cross-linked enzyme powders were prepared in various liquid media. • Insoluble enzymes were magnetized using iron oxides particles. • Magnetic iron oxides particles were prepared by microwave-assisted synthesis. • Magnetic modification was performed under low (freezing) temperature. • Cross-linked powdered trypsin and lipase can be used repeatedly for reaction.

  12. Targeted enzyme prodrug therapies.

    Science.gov (United States)

    Schellmann, N; Deckert, P M; Bachran, D; Fuchs, H; Bachran, C

    2010-09-01

    The cure of cancer is still a formidable challenge in medical science. Long-known modalities including surgery, chemotherapy and radiotherapy are successful in a number of cases; however, invasive, metastasized and inaccessible tumors still pose an unresolved and ongoing problem. Targeted therapies designed to locate, detect and specifically kill tumor cells have been developed in the past three decades as an alternative to treat troublesome cancers. Most of these therapies are either based on antibody-dependent cellular cytotoxicity, targeted delivery of cytotoxic drugs or tumor site-specific activation of prodrugs. The latter is a two-step procedure. In the first step, a selected enzyme is accumulated in the tumor by guiding the enzyme or its gene to the neoplastic cells. In the second step, a harmless prodrug is applied and specifically converted by this enzyme into a cytotoxic drug only at the tumor site. A number of targeting systems, enzymes and prodrugs were investigated and improved since the concept was first envisioned in 1974. This review presents a concise overview on the history and latest developments in targeted therapies for cancer treatment. We cover the relevant technologies such as antibody-directed enzyme prodrug therapy (ADEPT), gene-directed enzyme prodrug therapy (GDEPT) as well as related therapies such as clostridial- (CDEPT) and polymer-directed enzyme prodrug therapy (PDEPT) with emphasis on prodrug-converting enzymes, prodrugs and drugs.

  13. Enzymes in Fermented Fish.

    Science.gov (United States)

    Giyatmi; Irianto, H E

    Fermented fish products are very popular particularly in Southeast Asian countries. These products have unique characteristics, especially in terms of aroma, flavor, and texture developing during fermentation process. Proteolytic enzymes have a main role in hydrolyzing protein into simpler compounds. Fermentation process of fish relies both on naturally occurring enzymes (in the muscle or the intestinal tract) as well as bacteria. Fermented fish products processed using the whole fish show a different characteristic compared to those prepared from headed and gutted fish. Endogenous enzymes like trypsin, chymotrypsin, elastase, and aminopeptidase are the most involved in the fermentation process. Muscle tissue enzymes like cathepsins, peptidases, transaminases, amidases, amino acid decarboxylases, glutamic dehydrogenases, and related enzymes may also play a role in fish fermentation. Due to the decreased bacterial number during fermentation, contribution of microbial enzymes to proteolysis may be expected prior to salting of fish. Commercial enzymes are supplemented during processing for specific purposes, such as quality improvement and process acceleration. In the case of fish sauce, efforts to accelerate fermentation process and to improve product quality have been studied by addition of enzymes such as papain, bromelain, trypsin, pepsin, and chymotrypsin. © 2017 Elsevier Inc. All rights reserved.

  14. Radiation inactivation analysis of enzymes. Effect of free radical scavengers on apparent target sizes

    International Nuclear Information System (INIS)

    Eichler, D.C.; Solomonson, L.P.; Barber, M.J.; McCreery, M.J.; Ness, G.C.

    1987-01-01

    In most cases the apparent target size obtained by radiation inactivation analysis corresponds to the subunit size or to the size of a multimeric complex. In this report, we examined whether the larger than expected target sizes of some enzymes could be due to secondary effects of free radicals. To test this proposal we carried out radiation inactivation analysis on Escherichia coli DNA polymerase I, Torula yeast glucose-6-phosphate dehydrogenase, Chlorella vulgaris nitrate reductase, and chicken liver sulfite oxidase in the presence and absence of free radical scavengers (benzoic acid and mannitol). In the presence of free radical scavengers, inactivation curves are shifted toward higher radiation doses. Plots of scavenger concentration versus enzyme activity showed that the protective effect of benzoic acid reached a maximum at 25 mM then declined. Mannitol alone had little effect, but appeared to broaden the maximum protective range of benzoic acid relative to concentration. The apparent target size of the polymerase activity of DNA polymerase I in the presence of free radical scavengers was about 40% of that observed in the absence of these agents. This is considerably less than the minimum polypeptide size and may reflect the actual size of the polymerase functional domain. Similar effects, but of lesser magnitude, were observed for glucose-6-phosphate dehydrogenase, nitrate reductase, and sulfite oxidase. These results suggest that secondary damage due to free radicals generated in the local environment as a result of ionizing radiation can influence the apparent target size obtained by this method

  15. Enzymic lactose hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J J; Brand, J C

    1980-01-01

    Acid or enzymic hydrolysis can be used to hydrolyze lactose. Advantages of both are compared and details of enzymic hydrolysis using yeast or fungal enzymes given. The new scheme outlined involves recycling lactase. Because lactose and lactase react to ultrafiltration (UF) membranes differently separation is possible. Milk or milk products are ultrafiltered to separate a concentrate from a lactose-rich permeate which is treated with lactase in a reactor until hydrolysis reaches a required level. The lactase can be removed by UF as it does not permeate the membrane, and it is recycled back to the reactor. Permeate from the second UF stage may or may not be recombined with the concentrate from the first stage to produce a low lactose product (analysis of a typical low-lactose dried whole milk is given). Batch or continuous processes are explained and a batch process without enzyme recovery is discussed. (Refs. 4).

  16. Indicators: Sediment Enzymes

    Science.gov (United States)

    Sediment enzymes are proteins that are produced by microorganisms living in the sediment or soil. They are indicators of key ecosystem processes and can help determine which nutrients are affecting the biological community of a waterbody.

  17. Enzyme Vs. Extremozyme -32 ...

    Indian Academy of Sciences (India)

    Enzymes are biocatalytic protein molecules that enhance the rates of ... to physical forces (hydrogen bonds, hydrophobic 1, electrostatic and Van der ... conformation. In 1995 ... surface against 14.7% in Klenow poll (some of the hydrophobic.

  18. Overproduction of ligninolytic enzymes

    Science.gov (United States)

    Elisashvili, Vladimir; Kachlishvili, Eva; Torok, Tamas

    2014-06-17

    Methods, compositions, and systems for overproducing ligninolytic enzymes from the basidiomycetous fungus are described herein. As described, the method can include incubating a fungal strain of Cerrena unicolor IBB 303 in a fermentation system having growth medium which includes lignocellulosic material and then cultivating the fungal strain in the fermentation system under conditions wherein the fungus expresses the ligninolytic enzymes. In some cases, the lignocellulosic material is mandarin peel, ethanol production residue, walnut pericarp, wheat bran, wheat straw, or banana peel.

  19. Measurement of enzyme activity.

    Science.gov (United States)

    Harris, T K; Keshwani, M M

    2009-01-01

    To study and understand the nature of living cells, scientists have continually employed traditional biochemical techniques aimed to fractionate and characterize a designated network of macromolecular components required to carry out a particular cellular function. At the most rudimentary level, cellular functions ultimately entail rapid chemical transformations that otherwise would not occur in the physiological environment of the cell. The term enzyme is used to singularly designate a macromolecular gene product that specifically and greatly enhances the rate of a chemical transformation. Purification and characterization of individual and collective groups of enzymes has been and will remain essential toward advancement of the molecular biological sciences; and developing and utilizing enzyme reaction assays is central to this mission. First, basic kinetic principles are described for understanding chemical reaction rates and the catalytic effects of enzymes on such rates. Then, a number of methods are described for measuring enzyme-catalyzed reaction rates, which mainly differ with regard to techniques used to detect and quantify concentration changes of given reactants or products. Finally, short commentary is given toward formulation of reaction mixtures used to measure enzyme activity. Whereas a comprehensive treatment of enzymatic reaction assays is not within the scope of this chapter, the very core principles that are presented should enable new researchers to better understand the logic and utility of any given enzymatic assay that becomes of interest.

  20. First Experience from the World Largest fully commercial Solar Heating Plant

    DEFF Research Database (Denmark)

    Heller, Alfred; Furbo, Simon

    1997-01-01

    The first experience from the largest solar heating plant in the world is given. The plant is situated in Marstal and is has a total area of 8000 square m.......The first experience from the largest solar heating plant in the world is given. The plant is situated in Marstal and is has a total area of 8000 square m....

  1. Revisiting the phylogeny of Ocellularieae, the second largest tribe within Graphidaceae (lichenized Ascomycota: Ostropales)

    Science.gov (United States)

    Ekaphan Kraichak; Sittiporn Parnmen; Robert Lücking; Eimy Rivas Plata; Andre Aptroot; Marcela E.S. Caceres; Damien Ertz; Armin Mangold; Joel A. Mercado-Diaz; Khwanruan Papong; Dries Van der Broeck; Gothamie Weerakoon; H. Thorsten. Lumbsch; NO-VALUE

    2014-01-01

    We present an updated 3-locus molecular phylogeny of tribe Ocellularieae, the second largest tribe within subfamily Graphidoideae in the Graphidaceae. Adding 165 newly generated sequences from the mitochondrial small subunit rDNA (mtSSU), the nuclear large subunit rDNA (nuLSU), and the second largest subunit of the DNA-directed RNA polymerase II (RPB2), we currently...

  2. Random-walk enzymes

    Science.gov (United States)

    Mak, Chi H.; Pham, Phuong; Afif, Samir A.; Goodman, Myron F.

    2015-09-01

    Enzymes that rely on random walk to search for substrate targets in a heterogeneously dispersed medium can leave behind complex spatial profiles of their catalyzed conversions. The catalytic signatures of these random-walk enzymes are the result of two coupled stochastic processes: scanning and catalysis. Here we develop analytical models to understand the conversion profiles produced by these enzymes, comparing an intrusive model, in which scanning and catalysis are tightly coupled, against a loosely coupled passive model. Diagrammatic theory and path-integral solutions of these models revealed clearly distinct predictions. Comparison to experimental data from catalyzed deaminations deposited on single-stranded DNA by the enzyme activation-induced deoxycytidine deaminase (AID) demonstrates that catalysis and diffusion are strongly intertwined, where the chemical conversions give rise to new stochastic trajectories that were absent if the substrate DNA was homogeneous. The C →U deamination profiles in both analytical predictions and experiments exhibit a strong contextual dependence, where the conversion rate of each target site is strongly contingent on the identities of other surrounding targets, with the intrusive model showing an excellent fit to the data. These methods can be applied to deduce sequence-dependent catalytic signatures of other DNA modification enzymes, with potential applications to cancer, gene regulation, and epigenetics.

  3. Thioredoxin Cross-Linking by Nitrogen Mustard in Lung Epithelial Cells: Formation of Multimeric Thioredoxin/Thioredoxin Reductase Complexes and Inhibition of Disulfide Reduction

    OpenAIRE

    Jan, Yi-Hua; Heck, Diane E.; Casillas, Robert P.; Laskin, Debra L.; Laskin, Jeffrey D.

    2015-01-01

    The thioredoxin (Trx) system, which consists of Trx and thioredoxin reductase (TrxR), is a major cellular disulfide reduction system important in antioxidant defense. TrxR is a target of mechlorethamine (methylbis(2-chloroethyl)amine; HN2), a bifunctional alkylating agent that covalently binds to selenocysteine/cysteine residues in the redox centers of the enzyme, leading to inactivation and toxicity. Mammalian Trx contains two catalytic cysteines; herein, we determined if HN2 also targets Tr...

  4. Matrix Metalloproteinase Enzyme Family

    Directory of Open Access Journals (Sweden)

    Ozlem Goruroglu Ozturk

    2013-04-01

    Full Text Available Matrix metalloproteinases play an important role in many biological processes such as embriogenesis, tissue remodeling, wound healing, and angiogenesis, and in some pathological conditions such as atherosclerosis, arthritis and cancer. Currently, 24 genes have been identified in humans that encode different groups of matrix metalloproteinase enzymes. This review discuss the members of the matrix metalloproteinase family and their substrate specificity, structure, function and the regulation of their enzyme activity by tissue inhibitors. [Archives Medical Review Journal 2013; 22(2.000: 209-220

  5. A marine heatwave drives massive losses from the world’s largest seagrass carbon stocks

    KAUST Repository

    Arias-Ortiz, Ariane; Serrano, Oscar; Masqué , Pere; Lavery, P. S.; Mueller, U.; Kendrick, G. A.; Rozaimi, M.; Esteban, A.; Fourqurean, J. W.; Marbà , N.; Mateo, M. A.; Murray, K.; Rule, M. J.; Duarte, Carlos M.

    2018-01-01

    Seagrass ecosystems contain globally significant organic carbon (C) stocks. However, climate change and increasing frequency of extreme events threaten their preservation. Shark Bay, Western Australia, has the largest C stock reported for a seagrass

  6. New Chicago-Indiana computer network will handle dataflow from world's largest scientific experiment

    CERN Multimedia

    2006-01-01

    "Massive quantities of data will soon begin flowing from the largest scientific instrument ever built into an international netword of computer centers, including one operated jointly by the University of Chicago and Indiana University." (1,5 page)

  7. Lagisza, world's largest CFB boiler, begins commercial operation

    Energy Technology Data Exchange (ETDEWEB)

    Nuortimo, K. [Foster Wheeler, Varkaus (Finland)

    2010-04-15

    Early operating experience with the Lagisza circulating fluidised bed (CFB) boiler in Poland - the world's largest such boiler to date, and also the first one with supercritical steam conditions - has been positive. 3 figs., 4 tabs.

  8. Analytic approximation to the largest eigenvalue distribution of a white Wishart matrix

    CSIR Research Space (South Africa)

    Vlok, JD

    2012-08-14

    Full Text Available offers largely simplified computation and provides statistics such as the mean value and region of support of the largest eigenvalue distribution. Numeric results from the literature are compared with the approximation and Monte Carlo simulation results...

  9. Magnetically responsive enzyme powders

    Czech Academy of Sciences Publication Activity Database

    Pospišková, K.; Šafařík, Ivo

    2015-01-01

    Roč. 380, APR 2015 (2015), s. 197-200 ISSN 0304-8853 R&D Projects: GA MŠk(CZ) LD13021 Institutional support: RVO:67179843 Keywords : enzyme powders * cross-linking * magnetic modification * magnetic separation * magnetic iron oxides particles * microwave-assisted synthesis Subject RIV: CE - Biochemistry Impact factor: 2.357, year: 2015

  10. Enzyme with rhamnogalacturonase activity.

    NARCIS (Netherlands)

    Kofod, L.V.; Andersen, L.N.; Dalboge, H.; Kauppinen, M.S.; Christgau, S.; Heldt-Hansen, H.P.; Christophersen, C.; Nielsen, P.M.; Voragen, A.G.J.; Schols, H.A.

    1998-01-01

    An enzyme exhibiting rhamnogalacturonase activity, capable of cleaving a rhamnogalacturonan backbone in such a manner that galacturonic acids are left as the non-reducing ends, and which exhibits activity on hairy regions from a soy bean material and/or on saponified hairy regions from a sugar beet

  11. Implantable enzyme amperometric biosensors.

    Science.gov (United States)

    Kotanen, Christian N; Moussy, Francis Gabriel; Carrara, Sandro; Guiseppi-Elie, Anthony

    2012-05-15

    The implantable enzyme amperometric biosensor continues as the dominant in vivo format for the detection, monitoring and reporting of biochemical analytes related to a wide range of pathologies. Widely used in animal studies, there is increasing emphasis on their use in diabetes care and management, the management of trauma-associated hemorrhage and in critical care monitoring by intensivists in the ICU. These frontier opportunities demand continuous indwelling performance for up to several years, well in excess of the currently approved seven days. This review outlines the many challenges to successful deployment of chronically implantable amperometric enzyme biosensors and emphasizes the emerging technological approaches in their continued development. The foreign body response plays a prominent role in implantable biotransducer failure. Topics considering the approaches to mitigate the inflammatory response, use of biomimetic chemistries, nanostructured topographies, drug eluting constructs, and tissue-to-device interface modulus matching are reviewed. Similarly, factors that influence biotransducer performance such as enzyme stability, substrate interference, mediator selection and calibration are reviewed. For the biosensor system, the opportunities and challenges of integration, guided by footprint requirements, the limitations of mixed signal electronics, and power requirements, has produced three systems approaches. The potential is great. However, integration along the multiple length scales needed to address fundamental issues and integration across the diverse disciplines needed to achieve success of these highly integrated systems, continues to be a challenge in the development and deployment of implantable amperometric enzyme biosensor systems. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Advances in enzyme bioelectrochemistry

    Directory of Open Access Journals (Sweden)

    ANDRESSA R. PEREIRA

    Full Text Available ABSTRACT Bioelectrochemistry can be defined as a branch of Chemical Science concerned with electron-proton transfer and transport involving biomolecules, as well as electrode reactions of redox enzymes. The bioelectrochemical reactions and system have direct impact in biotechnological development, in medical devices designing, in the behavior of DNA-protein complexes, in green-energy and bioenergy concepts, and make it possible an understanding of metabolism of all living organisms (e.g. humans where biomolecules are integral to health and proper functioning. In the last years, many researchers have dedicated itself to study different redox enzymes by using electrochemistry, aiming to understand their mechanisms and to develop promising bioanodes and biocathodes for biofuel cells as well as to develop biosensors and implantable bioelectronics devices. Inside this scope, this review try to introduce and contemplate some relevant topics for enzyme bioelectrochemistry, such as the immobilization of the enzymes at electrode surfaces, the electron transfer, the bioelectrocatalysis, and new techniques conjugated with electrochemistry vising understand the kinetics and thermodynamics of redox proteins. Furthermore, examples of recent approaches in designing biosensors and biofuel developed are presented.

  13. Cold-Adapted Enzymes

    Science.gov (United States)

    Georlette, D.; Bentahir, M.; Claverie, P.; Collins, T.; D'amico, S.; Delille, D.; Feller, G.; Gratia, E.; Hoyoux, A.; Lonhienne, T.; Meuwis, M.-a.; Zecchinon, L.; Gerday, Ch.

    In the last few years, increased attention has been focused on enzymes produced by cold-adapted micro-organisms. It has emerged that psychrophilic enzymes represent an extremely powerful tool in both protein folding investigations and for biotechnological purposes. Such enzymes are characterised by an increased thermosensitivity and, most of them, by a higher catalytic efficiency at low and moderate temperatures, when compared to their mesophilic counterparts. The high thermosensitivity probably originates from an increased flexibility of either a selected area of the molecular edifice or the overall protein structure, providing enhanced abilities to undergo conformational changes during catalysis at low temperatures. Structure modelling and recent crystallographic data have allowed to elucidate the structural parameters that could be involved in this higher resilience. It was demonstrated that each psychrophilic enzyme adopts its own adaptive strategy. It appears, moreover, that there is a continuum in the strategy of protein adaptation to temperature, as the previously mentioned structural parameters are implicated in the stability of thermophilic proteins. Additional 3D crystal structures, site-directed and random mutagenesis experiments should now be undertaken to further investigate the stability-flexibility-activity relationship.

  14. Embedded enzymes catalyse capture

    Science.gov (United States)

    Kentish, Sandra

    2018-05-01

    Membrane technologies for carbon capture can offer economic and environmental advantages over conventional amine-based absorption, but can suffer from limited gas flux and selectivity to CO2. Now, a membrane based on enzymes embedded in hydrophilic pores is shown to exhibit combined flux and selectivity that challenges the state of the art.

  15. Photoperiodism and Enzyme Activity

    Science.gov (United States)

    Queiroz, Orlando; Morel, Claudine

    1974-01-01

    Metabolic readjustments after a change from long days to short days appear, in Kalanchoe blossfeldiana, to be achieved through the operation of two main mechanisms: variation in enzyme capacity, and circadian rhythmicity. After a lag time, capacity in phosphoenolpyruvate carboxylase and capacity in aspartate aminotransferase increase exponentially and appear to be allometrically linked during 50 to 60 short days; then a sudden fall takes place in the activity of the former. Malic enzyme and alanine aminotransferase behave differently. Thus, the operation of the two sections of the pathway (before and after the malate step) give rise to a continuously changing functional compartmentation in the pathway. Circadian rhythmicity, on the other hand, produces time compartmentation through phase shifts and variation in amplitude, independently for each enzyme. These characteristics suggest that the operation of a so-called biological clock would be involved. We propose the hypothesis that feedback regulation would be more accurate and efficient when applied to an already oscillating, clock-controlled enzyme system. PMID:16658749

  16. ISFET based enzyme sensors

    NARCIS (Netherlands)

    van der Schoot, Bart H.; Bergveld, Piet

    1987-01-01

    This paper reviews the results that have been reported on ISFET based enzyme sensors. The most important improvement that results from the application of ISFETs instead of glass membrane electrodes is in the method of fabrication. Problems with regard to the pH dependence of the response and the

  17. The Enzyme Function Initiative†

    Science.gov (United States)

    Gerlt, John A.; Allen, Karen N.; Almo, Steven C.; Armstrong, Richard N.; Babbitt, Patricia C.; Cronan, John E.; Dunaway-Mariano, Debra; Imker, Heidi J.; Jacobson, Matthew P.; Minor, Wladek; Poulter, C. Dale; Raushel, Frank M.; Sali, Andrej; Shoichet, Brian K.; Sweedler, Jonathan V.

    2011-01-01

    The Enzyme Function Initiative (EFI) was recently established to address the challenge of assigning reliable functions to enzymes discovered in bacterial genome projects; in this Current Topic we review the structure and operations of the EFI. The EFI includes the Superfamily/Genome, Protein, Structure, Computation, and Data/Dissemination Cores that provide the infrastructure for reliably predicting the in vitro functions of unknown enzymes. The initial targets for functional assignment are selected from five functionally diverse superfamilies (amidohydrolase, enolase, glutathione transferase, haloalkanoic acid dehalogenase, and isoprenoid synthase), with five superfamily-specific Bridging Projects experimentally testing the predicted in vitro enzymatic activities. The EFI also includes the Microbiology Core that evaluates the in vivo context of in vitro enzymatic functions and confirms the functional predictions of the EFI. The deliverables of the EFI to the scientific community include: 1) development of a large-scale, multidisciplinary sequence/structure-based strategy for functional assignment of unknown enzymes discovered in genome projects (target selection, protein production, structure determination, computation, experimental enzymology, microbiology, and structure-based annotation); 2) dissemination of the strategy to the community via publications, collaborations, workshops, and symposia; 3) computational and bioinformatic tools for using the strategy; 4) provision of experimental protocols and/or reagents for enzyme production and characterization; and 5) dissemination of data via the EFI’s website, enzymefunction.org. The realization of multidisciplinary strategies for functional assignment will begin to define the full metabolic diversity that exists in nature and will impact basic biochemical and evolutionary understanding, as well as a wide range of applications of central importance to industrial, medicinal and pharmaceutical efforts. PMID

  18. The Enzyme Function Initiative.

    Science.gov (United States)

    Gerlt, John A; Allen, Karen N; Almo, Steven C; Armstrong, Richard N; Babbitt, Patricia C; Cronan, John E; Dunaway-Mariano, Debra; Imker, Heidi J; Jacobson, Matthew P; Minor, Wladek; Poulter, C Dale; Raushel, Frank M; Sali, Andrej; Shoichet, Brian K; Sweedler, Jonathan V

    2011-11-22

    The Enzyme Function Initiative (EFI) was recently established to address the challenge of assigning reliable functions to enzymes discovered in bacterial genome projects; in this Current Topic, we review the structure and operations of the EFI. The EFI includes the Superfamily/Genome, Protein, Structure, Computation, and Data/Dissemination Cores that provide the infrastructure for reliably predicting the in vitro functions of unknown enzymes. The initial targets for functional assignment are selected from five functionally diverse superfamilies (amidohydrolase, enolase, glutathione transferase, haloalkanoic acid dehalogenase, and isoprenoid synthase), with five superfamily specific Bridging Projects experimentally testing the predicted in vitro enzymatic activities. The EFI also includes the Microbiology Core that evaluates the in vivo context of in vitro enzymatic functions and confirms the functional predictions of the EFI. The deliverables of the EFI to the scientific community include (1) development of a large-scale, multidisciplinary sequence/structure-based strategy for functional assignment of unknown enzymes discovered in genome projects (target selection, protein production, structure determination, computation, experimental enzymology, microbiology, and structure-based annotation), (2) dissemination of the strategy to the community via publications, collaborations, workshops, and symposia, (3) computational and bioinformatic tools for using the strategy, (4) provision of experimental protocols and/or reagents for enzyme production and characterization, and (5) dissemination of data via the EFI's Website, http://enzymefunction.org. The realization of multidisciplinary strategies for functional assignment will begin to define the full metabolic diversity that exists in nature and will impact basic biochemical and evolutionary understanding, as well as a wide range of applications of central importance to industrial, medicinal, and pharmaceutical efforts.

  19. Footprinting analysis of interactions between the largest eukaryotic RNase P/MRP protein Pop1 and RNase P/MRP RNA components.

    Science.gov (United States)

    Fagerlund, Robert D; Perederina, Anna; Berezin, Igor; Krasilnikov, Andrey S

    2015-09-01

    Ribonuclease (RNase) P and RNase MRP are closely related catalytic ribonucleoproteins involved in the metabolism of a wide range of RNA molecules, including tRNA, rRNA, and some mRNAs. The catalytic RNA component of eukaryotic RNase P retains the core elements of the bacterial RNase P ribozyme; however, the peripheral RNA elements responsible for the stabilization of the global architecture are largely absent in the eukaryotic enzyme. At the same time, the protein makeup of eukaryotic RNase P is considerably more complex than that of the bacterial RNase P. RNase MRP, an essential and ubiquitous eukaryotic enzyme, has a structural organization resembling that of eukaryotic RNase P, and the two enzymes share most of their protein components. Here, we present the results of the analysis of interactions between the largest protein component of yeast RNases P/MRP, Pop1, and the RNA moieties of the enzymes, discuss structural implications of the results, and suggest that Pop1 plays the role of a scaffold for the stabilization of the global architecture of eukaryotic RNase P RNA, substituting for the network of RNA-RNA tertiary interactions that maintain the global RNA structure in bacterial RNase P. © 2015 Fagerlund et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

  20. The Multivariate Largest Lyapunov Exponent as an Age-Related Metric of Quiet Standing Balance

    Directory of Open Access Journals (Sweden)

    Kun Liu

    2015-01-01

    Full Text Available The largest Lyapunov exponent has been researched as a metric of the balance ability during human quiet standing. However, the sensitivity and accuracy of this measurement method are not good enough for clinical use. The present research proposes a metric of the human body’s standing balance ability based on the multivariate largest Lyapunov exponent which can quantify the human standing balance. The dynamic multivariate time series of ankle, knee, and hip were measured by multiple electrical goniometers. Thirty-six normal people of different ages participated in the test. With acquired data, the multivariate largest Lyapunov exponent was calculated. Finally, the results of the proposed approach were analysed and compared with the traditional method, for which the largest Lyapunov exponent and power spectral density from the centre of pressure were also calculated. The following conclusions can be obtained. The multivariate largest Lyapunov exponent has a higher degree of differentiation in differentiating balance in eyes-closed conditions. The MLLE value reflects the overall coordination between multisegment movements. Individuals of different ages can be distinguished by their MLLE values. The standing stability of human is reduced with the increment of age.

  1. Identifying the node spreading influence with largest k-core values

    International Nuclear Information System (INIS)

    Lin, Jian-Hong; Guo, Qiang; Dong, Wen-Zhao; Tang, Li-Ying; Liu, Jian-Guo

    2014-01-01

    Identifying the nodes with largest spreading influence of complex networks is one of the most promising domains. By taking into account the neighbors' k-core values, we present an improved neighbors' k-core (INK) method which is the sum of the neighbors' k-core values with a tunable parameter α to evaluate the node spreading influence with largest k-core values. Comparing with the Susceptible–Infected–Recovered (SIR) results for four real networks, the INK method could identify the node spreading influence with largest k-core values more accurately than the ones generated by the degree k, closeness C, betweenness B and coreness centrality method. - Highlights: • We present an improved neighbors' k-core (INK) method to evaluate the node spreading influence with largest k-core values. • The INK method could identify the node spreading influence with largest k-core values more accurately. • Kendall's tau τ of INK method with α=1 are highly identical to rank the node influence

  2. NRSA enzyme decomposition model data

    Data.gov (United States)

    U.S. Environmental Protection Agency — Microbial enzyme activities measured at more than 2000 US streams and rivers. These enzyme data were then used to predict organic matter decomposition and microbial...

  3. Cellulase enzyme and biomass utilization

    African Journals Online (AJOL)

    STORAGESEVER

    2009-06-03

    Jun 3, 2009 ... human population grows and economic development. However, the current .... conditions and the production cost of the related enzyme system. Therefore ... Given the importance of this enzyme to these so many industries,.

  4. Discovery of the Largest Orbweaving Spider Species: The Evolution of Gigantism in Nephila

    OpenAIRE

    Kuntner, Matja?; Coddington, Jonathan A.

    2009-01-01

    Background More than 41,000 spider species are known with about 400?500 added each year, but for some well-known groups, such as the giant golden orbweavers, Nephila, the last valid described species dates from the 19th century. Nephila are renowned for being the largest web-spinning spiders, making the largest orb webs, and are model organisms for the study of extreme sexual size dimorphism (SSD) and sexual biology. Here, we report on the discovery of a new, giant Nephila species from Africa...

  5. Effect of ionizing radiation on enzymes. VII

    International Nuclear Information System (INIS)

    Libicky, A.; Fidlerova, J.; Pipota, J.

    1992-01-01

    The effect was examined of gamma radiation on the efficacy of cellulase irradiated with doses graded from 10 to 120 kGy. The results were statistically evaluated. The dose dependence of inactivation corresponds to the course of the decrease in efficacy of pancreatic proteolytic enzymes and pepsin investigated in previous communications. In the semilogarithmical arrangement of the graph this dependence is linear. It can be seen from the graph that a dose of 10 kGy, usually sufficient to achieve microbiological indefectibility, produces an approximately 7% loss in efficacy. With a dose of 25 kGy necessary to achieve sterility, cellulase already loses approximately 17% of its efficacy. With 120 kGy, the largest dose used, the efficacy was reduced to only 47.9%. (author) 3 figs., 1 tab., 13 refs

  6. CERN: Digital image analysis in the world's largest research center for particle physics

    CERN Multimedia

    2005-01-01

    Those interested in researching into the smallest building blocks that matter is made up of need the largest instruments. CERN, near Geneva, Switzerland is where the most powerful circular accelerator in the world is being built: the Large Hadron Collider (LHC) for proton collisions. It has a circumference of 26.7 km (4 pages)

  7. Mass balance of Greenland's three largest outlet glaciers - 2000–2010

    NARCIS (Netherlands)

    Howat, I.M.; Ahn, Y.; Joughin, I.; van den Broeke, M.R.; Lenaerts, J.T.M.; Smith, B.

    2011-01-01

    Acceleration of Greenland's three largest outlet glaciers, Helheim, Kangerdlugssuaq and Jakobshavn Isbræ, accounted for a substantial portion of the ice sheet's mass loss over the past decade. Rapid changes in their discharge, however, make their cumulative mass-change uncertain. We derive monthly

  8. Key U.S.-built part fails during testing for world's largest particle collider

    CERN Multimedia

    2007-01-01

    "Scientists are scrambling to redesign a key U.S.-built part that broke "with a loud bang and a cloud of dust" during a high-pressure test for the world's largest particle physics collider that is supposed to start up in November, officials sais Tuesday." (1,5 page)

  9. CERN, World's largest particle physics lab, selects Progress SonicMQ

    CERN Document Server

    2007-01-01

    "Progress Software Corporation (NADAQ: PRGS), a global supplier of application insfrastructure software used to develop, deploy, integrate and manage business applications, today announced that CERN the world's largest physis laboratory and particle accelerator, has chosen Progress® SonicMQ® for mission-critical message delivery." (1 page)

  10. Phase space reconstruction and estimation of the largest Lyapunov exponent for gait kinematic data

    Energy Technology Data Exchange (ETDEWEB)

    Josiński, Henryk [Silesian University of Technology, Akademicka 16, 44-100 Gliwice (Poland); Świtoński, Adam [Polish-Japanese Institute of Information Technology, Aleja Legionów 2, 41-902 Bytom (Poland); Silesian University of Technology, Akademicka 16, 44-100 Gliwice (Poland); Michalczuk, Agnieszka; Wojciechowski, Konrad [Polish-Japanese Institute of Information Technology, Aleja Legionów 2, 41-902 Bytom (Poland)

    2015-03-10

    The authors describe an example of application of nonlinear time series analysis directed at identifying the presence of deterministic chaos in human motion data by means of the largest Lyapunov exponent. The method was previously verified on the basis of a time series constructed from the numerical solutions of both the Lorenz and the Rössler nonlinear dynamical systems.

  11. Discovery of the largest orbweaving spider species: the evolution of gigantism in Nephila.

    Science.gov (United States)

    Kuntner, Matjaz; Coddington, Jonathan A

    2009-10-21

    More than 41,000 spider species are known with about 400-500 added each year, but for some well-known groups, such as the giant golden orbweavers, Nephila, the last valid described species dates from the 19(th) century. Nephila are renowned for being the largest web-spinning spiders, making the largest orb webs, and are model organisms for the study of extreme sexual size dimorphism (SSD) and sexual biology. Here, we report on the discovery of a new, giant Nephila species from Africa and Madagascar, and review size evolution and SSD in Nephilidae. We formally describe N. komaci sp. nov., the largest web spinning species known, and place the species in phylogenetic context to reconstruct the evolution of mean size (via squared change parsimony). We then test female and male mean size correlation using phylogenetically independent contrasts, and simulate nephilid body size evolution using Monte Carlo statistics. Nephila females increased in size almost monotonically to establish a mostly African clade of true giants. In contrast, Nephila male size is effectively decoupled and hovers around values roughly one fifth of female size. Although N. komaci females are the largest Nephila yet discovered, the males are also large and thus their SSD is not exceptional.

  12. Predicting Traffic Flow in Local Area Networks by the Largest Lyapunov Exponent

    Directory of Open Access Journals (Sweden)

    Yan Liu

    2016-01-01

    Full Text Available The dynamics of network traffic are complex and nonlinear, and chaotic behaviors and their prediction, which play an important role in local area networks (LANs, are studied in detail, using the largest Lyapunov exponent. With the introduction of phase space reconstruction based on the time sequence, the high-dimensional traffic is projected onto the low dimension reconstructed phase space, and a reduced dynamic system is obtained from the dynamic system viewpoint. Then, a numerical method for computing the largest Lyapunov exponent of the low-dimensional dynamic system is presented. Further, the longest predictable time, which is related to chaotic behaviors in the system, is studied using the largest Lyapunov exponent, and the Wolf method is used to predict the evolution of the traffic in a local area network by both Dot and Interval predictions, and a reliable result is obtained by the presented method. As the conclusion, the results show that the largest Lyapunov exponent can be used to describe the sensitivity of the trajectory in the reconstructed phase space to the initial values. Moreover, Dot Prediction can effectively predict the flow burst. The numerical simulation also shows that the presented method is feasible and efficient for predicting the complex dynamic behaviors in LAN traffic, especially for congestion and attack in networks, which are the main two complex phenomena behaving as chaos in networks.

  13. Discovery of the largest orbweaving spider species: the evolution of gigantism in Nephila.

    Directory of Open Access Journals (Sweden)

    Matjaz Kuntner

    2009-10-01

    Full Text Available More than 41,000 spider species are known with about 400-500 added each year, but for some well-known groups, such as the giant golden orbweavers, Nephila, the last valid described species dates from the 19(th century. Nephila are renowned for being the largest web-spinning spiders, making the largest orb webs, and are model organisms for the study of extreme sexual size dimorphism (SSD and sexual biology. Here, we report on the discovery of a new, giant Nephila species from Africa and Madagascar, and review size evolution and SSD in Nephilidae.We formally describe N. komaci sp. nov., the largest web spinning species known, and place the species in phylogenetic context to reconstruct the evolution of mean size (via squared change parsimony. We then test female and male mean size correlation using phylogenetically independent contrasts, and simulate nephilid body size evolution using Monte Carlo statistics.Nephila females increased in size almost monotonically to establish a mostly African clade of true giants. In contrast, Nephila male size is effectively decoupled and hovers around values roughly one fifth of female size. Although N. komaci females are the largest Nephila yet discovered, the males are also large and thus their SSD is not exceptional.

  14. World's third-largest producer of nuclear power. Japan in need of energy

    International Nuclear Information System (INIS)

    Anon.

    2008-01-01

    Japan is the third largest oil consumer in the world behind the United States and China, and the second largest net importer of oil. Japan boasts one of the largest economies in the world. The country continues to experience a moderate economic recovery that began in 2003, following a decade of economic stagnation. Japan's real gross domestic product (GDP) grew by 2.5% in 2005 and 2.3% in 2004. The modest upturn over the last few years reflects higher business confidence in Japan, a surge in export demand led by exports to China, and robust consumer spending. Unemployment in Japan fell to 4.4% in 2005, down from an early 2003 peak of 5.5%. Japan has virtually no domestic oil or natural gas reserves, and in 2005 was the second largest net importer of crude oil in the world. Despite the country's dearth of hydrocarbon resources, Japanese companies have actively pursued upstream oil and natural gas projects overseas. Japan remains one of the major exporters of energy-sector capital equipment, and Japanese companies provide engineering, construction, and project management services for energy projects. (orig.)

  15. Distribution of the Largest Eigenvalues of the Levi-Smirnov Ensemble

    International Nuclear Information System (INIS)

    Wieczorek, W.

    2004-01-01

    We calculate the distribution of the k-th largest eigenvalue in the random matrix Levi - Smirnov Ensemble (LSE), using the spectral dualism between LSE and chiral Gaussian Unitary Ensemble (GUE). Then we reconstruct universal spectral oscillations and we investigate an asymptotic behavior of the spectral distribution. (author)

  16. Enzyme recycling in lignocellulosic biorefineries

    DEFF Research Database (Denmark)

    Jørgensen, Henning; Pinelo, Manuel

    2017-01-01

    platform. Cellulases are the most important enzymes required in this process, but the complex nature of lignocellulose requires several other enzymes (hemicellulases and auxiliary enzymes) for efficient hydrolysis. Enzyme recycling increases the catalytic productivity of the enzymes by reusing them...... for several batches of hydrolysis, and thereby reduces the overall cost associated with the hydrolysis. Research on this subject has been ongoing for many years and several promising technologies and methods have been developed and demonstrated. But only in a very few cases have these technologies been...... upscaled and tested in industrial settings, mainly because of many difficulties with recycling of enzymes from the complex lignocellulose hydrolyzate at industrially relevant conditions, i.e., high solids loadings. The challenges are associated with the large number of different enzymes required...

  17. Characterising Complex Enzyme Reaction Data.

    Directory of Open Access Journals (Sweden)

    Handan Melike Dönertaş

    Full Text Available The relationship between enzyme-catalysed reactions and the Enzyme Commission (EC number, the widely accepted classification scheme used to characterise enzyme activity, is complex and with the rapid increase in our knowledge of the reactions catalysed by enzymes needs revisiting. We present a manual and computational analysis to investigate this complexity and found that almost one-third of all known EC numbers are linked to more than one reaction in the secondary reaction databases (e.g., KEGG. Although this complexity is often resolved by defining generic, alternative and partial reactions, we have also found individual EC numbers with more than one reaction catalysing different types of bond changes. This analysis adds a new dimension to our understanding of enzyme function and might be useful for the accurate annotation of the function of enzymes and to study the changes in enzyme function during evolution.

  18. Differential genome-wide gene expression profiling of bovine largest and second-largest follicles: identification of genes associated with growth of dominant follicles

    Directory of Open Access Journals (Sweden)

    Takahashi Toru

    2010-02-01

    Full Text Available Abstract Background Bovine follicular development is regulated by numerous molecular mechanisms and biological pathways. In this study, we tried to identify differentially expressed genes between largest (F1 and second-largest follicles (F2, and classify them by global gene expression profiling using a combination of microarray and quantitative real-time PCR (QPCR analysis. The follicular status of F1 and F2 were further evaluated in terms of healthy and atretic conditions by investigating mRNA localization of identified genes. Methods Global gene expression profiles of F1 (10.7 +/- 0.7 mm and F2 (7.8 +/- 0.2 mm were analyzed by hierarchical cluster analysis and expression profiles of 16 representative genes were confirmed by QPCR analysis. In addition, localization of six identified transcripts was investigated in healthy and atretic follicles using in situ hybridization. The healthy or atretic condition of examined follicles was classified by progesterone and estradiol concentrations in follicular fluid. Results Hierarchical cluster analysis of microarray data classified the follicles into two clusters. Cluster A was composed of only F2 and was characterized by high expression of 31 genes including IGFBP5, whereas cluster B contained only F1 and predominantly expressed 45 genes including CYP19 and FSHR. QPCR analysis confirmed AMH, CYP19, FSHR, GPX3, PlGF, PLA2G1B, SCD and TRB2 were greater in F1 than F2, while CCL2, GADD45A, IGFBP5, PLAUR, SELP, SPP1, TIMP1 and TSP2 were greater in F2 than in F1. In situ hybridization showed that AMH and CYP19 were detected in granulosa cells (GC of healthy as well as atretic follicles. PlGF was localized in GC and in the theca layer (TL of healthy follicles. IGFBP5 was detected in both GC and TL of atretic follicles. GADD45A and TSP2 were localized in both GC and TL of atretic follicles, whereas healthy follicles expressed them only in GC. Conclusion We demonstrated that global gene expression profiling of F

  19. Measuring the Enzyme Activity of Arabidopsis Deubiquitylating Enzymes.

    Science.gov (United States)

    Kalinowska, Kamila; Nagel, Marie-Kristin; Isono, Erika

    2016-01-01

    Deubiquitylating enzymes, or DUBs, are important regulators of ubiquitin homeostasis and substrate stability, though the molecular mechanisms of most of the DUBs in plants are not yet understood. As different ubiquitin chain types are implicated in different biological pathways, it is important to analyze the enzyme characteristic for studying a DUB. Quantitative analysis of DUB activity is also important to determine enzyme kinetics and the influence of DUB binding proteins on the enzyme activity. Here, we show methods to analyze DUB activity using immunodetection, Coomassie Brilliant Blue staining, and fluorescence measurement that can be useful for understanding the basic characteristic of DUBs.

  20. Analysis of Multiple Structural Changes in Financial Contagion Based on the Largest Lyapunov Exponents

    Directory of Open Access Journals (Sweden)

    Rui Wang

    2014-01-01

    Full Text Available A modified multiple structural changes model is built to test structural breaks of the financial system based on calculating the largest Lyapunov exponents of the financial time series. Afterwards, the Lorenz system is used as a simulation example to inspect the new model. As the Lorenz system has strong nonlinearity, the verification results show that the new model has good capability in both finding the breakpoint and revealing the changes in nonlinear characteristics of the time series. The empirical study based on the model used daily data from the S&P 500 stock index during the global financial crisis from 2005 to 2012. The results provide four breakpoints of the period, which divide the contagion into four stages: stationary, local outbreak, global outbreak, and recovery period. An additional significant result is the obvious chaos characteristic difference in the largest Lyapunov exponents and the standard deviation at various stages, particularly at the local outbreak stage.

  1. Constraining the magnitude of the largest event in a foreshock-main shock-aftershock sequence

    Science.gov (United States)

    Shcherbakov, Robert; Zhuang, Jiancang; Ogata, Yosihiko

    2018-01-01

    Extreme value statistics and Bayesian methods are used to constrain the magnitudes of the largest expected earthquakes in a sequence governed by the parametric time-dependent occurrence rate and frequency-magnitude statistics. The Bayesian predictive distribution for the magnitude of the largest event in a sequence is derived. Two types of sequences are considered, that is, the classical aftershock sequences generated by large main shocks and the aftershocks generated by large foreshocks preceding a main shock. For the former sequences, the early aftershocks during a training time interval are used to constrain the magnitude of the future extreme event during the forecasting time interval. For the latter sequences, the earthquakes preceding the main shock are used to constrain the magnitudes of the subsequent extreme events including the main shock. The analysis is applied retrospectively to past prominent earthquake sequences.

  2. Investigation of Science Faculty with Education Specialties within the Largest University System in the United States

    OpenAIRE

    Bush, Seth D; Pelaez, Nancy; Rudd, James A, II; Stevens, Michael T; Tanner, Kimberly D; Williams, Kathy, PhD

    2011-01-01

    Efforts to improve science education include university science departments hiring Science Faculty with Education Specialties (SFES), scientists who take on specialized roles in science education within their discipline. Although these positions have existed for decades and may be growing more common, few reports have investigated the SFES approach to improving science education. We present comprehensive data on the SFES in the California State University (CSU) system, the largest university ...

  3. Opportunities for biodiversity gains under the world’s largest reforestation programme

    OpenAIRE

    Hua, Fangyuan; Wang, Xiaoyang; Zheng, Xinlei; Fisher, Brendan; Wang, Lin; Zhu, Jianguo; Tang, Ya; Yu, Douglas W.; Wilcove, David S.

    2016-01-01

    Reforestation is a critical means of addressing the environmental and social problems of deforestation. China’s Grain-for-Green Program (GFGP) is the world’s largest reforestation scheme. Here we provide the first nationwide assessment of the tree composition of GFGP forests and the first combined ecological and economic study aimed at understanding GFGP’s biodiversity implications. Across China, GFGP forests are overwhelmingly monocultures or compositionally simple mixed forests. Focusing on...

  4. Statistics of the largest sunspot and facular areas per solar cycle

    International Nuclear Information System (INIS)

    Willis, D.M.; Kabasakal Tulunay, Y.

    1979-01-01

    The statistics of extreme values is used to investigate the statistical properties of the largest areas sunspots and photospheric faculae per solar cycle. The largest values of the synodic-solar-rotation mean areas of umbrae, whole spots and faculae, which have been recorded for nine solar cycles, are each shown to comply with the general form of the extreme value probability function. Empirical expressions are derived for the three extreme value populations from which the characteristic statistical parameters, namely the mode, median, mean and standard deviation, can be calculated for each population. These three extreme value populations are also used to find the expected ranges of the extreme areas in a group of solar cycles as a function of the number of cycles in the group. The extreme areas of umbrae and whole spots have a dispersion comparable to that found by Siscoe for the extreme values of sunspot number, whereas the extreme areas of faculae have a smaller dispersion which is comparable to that found by Siscoe for the largest geomagnetic storm per solar cycle. The expected range of the largest sunspot area per solar cycle for a group of one hundred cycles appears to be inconsistent with the existence of the prolonged periods of sunspot minima that have been inferred from the historical information on solar variability. This inconsistency supports the contention that there are temporal changes of solar-cycle statistics during protracted periods of sunspot minima (or maxima). Indeed, without such temporal changes, photospheric faculae should have been continually observable throughout the lifetime of the Sun. (orig.)

  5. Trend of CO2 emissions of the 30 largest power plants in Germany

    International Nuclear Information System (INIS)

    Hermann, Hauke

    2014-01-01

    The brochure on the trend of CO 2 emissions of the 30 largest power plants in Germany includes tables of the emissions of these power plants. The CO 2 emissions of these power plants in 2013 (25% of the total German greenhouse gas emissions) have increased by 5% compared to 2012. The total CO 2 emission sin Germany increased by 1.5%. The differences between brown coal and black coal fired power plants are discussed.

  6. Natural radionuclides in soil profiles surrounding the largest coal-fired power plant in Serbia

    OpenAIRE

    Tanić Milan N.; Janković-Mandić Ljiljana J.; Gajić Boško A.; Daković Marko Z.; Dragović Snežana D.; Bačić Goran G.

    2016-01-01

    This study evaluates the influence of the largest Serbian coal-fired power plant on radionuclide concentrations in soil profiles up to 50 cm in depth. Thirty soil profiles were sampled from the plant surroundings (up to 10 km distance) and analyzed using standard methods for soil physicochemical properties and gamma ray spectrometry for specific activities of natural radionuclides (40K, 226Ra and 232Th). Spatial and vertical distribution of radionuclides wa...

  7. THE MASS OF (4) VESTA DERIVED FROM ITS LARGEST GRAVITATIONAL EFFECTS

    International Nuclear Information System (INIS)

    Kuzmanoski, Mike; Novakovic, Bojan; Apostolovska, Gordana

    2010-01-01

    In this paper, we present a recalculated value of the mass of (4) Vesta, derived from its largest gravitational perturbations on selected asteroids during their mutual close encounters. This was done by using a new method for mass determination, which is based on the linking of pre-encounter observations to the orbit determined from post-encounter ones. The estimated weighted mean of the mass of (4) Vesta is (1.300 ± 0.001) x 10 -10 M sun .

  8. Prostate Cancer Screening in Jamaica: Results of the Largest National Screening Clinic Prostate Cancer Screening in Jamaica: Results of the Largest National Screening Clinic

    International Nuclear Information System (INIS)

    Morrison, B. F.; Aiken, W.; Mayhew, R.; Gordon, Y.; Reid, M.

    2016-01-01

    Prostate cancer is highly prevalent in Jamaica and is the leading cause of cancer-related deaths. Our aim was to evaluate the patterns of screening in the largest organized screening clinic in Jamaica at the Jamaica Cancer Society. A retrospective analysis of all men presenting for screening at the Jamaica Cancer Society from 1995 to 2005 was done. All patients had digital rectal examinations (DRE) and prostate specific antigen (PSA) tests done. Results of prostate biopsies were noted. 1117 men of mean age 59.9 ± 8.2 years presented for screening. The median documented PSA was 1.6 ng/mL (maximum of 5170 ng/mL). Most patients presented for only 1 screen. There was a gradual reduction in the mean age of presentation for screening over the period. Prostate biopsies were requested on 11% of screening visits; however, only 59% of these were done. 5.6% of all persons screened were found to have cancer. Of the cancers diagnosed, Gleason 6 adenocarcinoma was the commonest grade and median PSA was 8.9 ng/mL (range 1.5-1059 ng/mL). Older men tend to screen for prostate cancer in Jamaica. However, compliance with regular maintenance visits and requests for confirmatory biopsies are poor. Screening needs intervention in the Jamaican population.

  9. THE CHALLENGE OF THE LARGEST STRUCTURES IN THE UNIVERSE TO COSMOLOGY

    International Nuclear Information System (INIS)

    Park, Changbom; Choi, Yun-Young; Kim, Sungsoo S.; Kim, Kap-Sung; Kim, Juhan; Gott III, J. Richard

    2012-01-01

    Large galaxy redshift surveys have long been used to constrain cosmological models and structure formation scenarios. In particular, the largest structures discovered observationally are thought to carry critical information on the amplitude of large-scale density fluctuations or homogeneity of the universe, and have often challenged the standard cosmological framework. The Sloan Great Wall (SGW) recently found in the Sloan Digital Sky Survey (SDSS) region casts doubt on the concordance cosmological model with a cosmological constant (i.e., the flat ΛCDM model). Here we show that the existence of the SGW is perfectly consistent with the ΛCDM model, a result that only our very large cosmological N-body simulation (the Horizon Run 2, HR2) could supply. In addition, we report on the discovery of a void complex in the SDSS much larger than the SGW, and show that such size of the largest void is also predicted in the ΛCDM paradigm. Our results demonstrate that an initially homogeneous isotropic universe with primordial Gaussian random phase density fluctuations growing in accordance with the general relativity can explain the richness and size of the observed large-scale structures in the SDSS. Using the HR2 simulation we predict that a future galaxy redshift survey about four times deeper or with 3 mag fainter limit than the SDSS should reveal a largest structure of bright galaxies about twice as big as the SGW.

  10. On the statistics of the largest geomagnetic storms per solar cycle

    International Nuclear Information System (INIS)

    Siscoe, G.L.

    1976-01-01

    The theory of extreme value statistics is applied to the first, second, and third largest geomagnetic storms in nine solar cycles measured by the average half-daily aa indices compiled by Mayaud. Analytic expressions giving the probability of the extremes per solar cycle as a contour function of storm magnitude are obtained by least squares fitting of the observations to the appropriate theoretical extreme value probability functions. The results are used to obtain the statistical characteristics (mode, median, mean, and standard deviation) for the extreme values. The results are applied to find the expected range of extreme values in a set as a function of the number of solar cycles in the set. We find that the expected range of the largest storm is quite narrow and is larger for the second and third largest storms. The observed range of the extreme half-daily aa index for the nine solar cycles is 354--546 γ. In a set of 100 cycles the range is expanded esentially to 311--680γ, an increase of only 39% in the range. The result supports the argument for a change in solar cycle statistics in the latter part of the Seventeenth Century (the Maunder minimum)

  11. Hospital Prices Increase in California, Especially Among Hospitals in the Largest Multi-hospital Systems

    Directory of Open Access Journals (Sweden)

    Glenn A. Melnick PhD

    2016-06-01

    Full Text Available A surge in hospital consolidation is fueling formation of ever larger multi-hospital systems throughout the United States. This article examines hospital prices in California over time with a focus on hospitals in the largest multi-hospital systems. Our data show that hospital prices in California grew substantially (+76% per hospital admission across all hospitals and all services between 2004 and 2013 and that prices at hospitals that are members of the largest, multi-hospital systems grew substantially more (113% than prices paid to all other California hospitals (70%. Prices were similar in both groups at the start of the period (approximately $9200 per admission. By the end of the period, prices at hospitals in the largest systems exceeded prices at other California hospitals by almost $4000 per patient admission. Our study findings are potentially useful to policy makers across the country for several reasons. Our data measure actual prices for a large sample of hospitals over a long period of time in California. California experienced its wave of consolidation much earlier than the rest of the country and as such our findings may provide some insights into what may happen across the United States from hospital consolidation including growth of large, multi-hospital systems now forming in the rest of the rest of the country.

  12. Collaborative spectrum sensing based on the ratio between largest eigenvalue and Geometric mean of eigenvalues

    KAUST Repository

    Shakir, Muhammad

    2011-12-01

    In this paper, we introduce a new detector referred to as Geometric mean detector (GEMD) which is based on the ratio of the largest eigenvalue to the Geometric mean of the eigenvalues for collaborative spectrum sensing. The decision threshold has been derived by employing Gaussian approximation approach. In this approach, the two random variables, i.e. The largest eigenvalue and the Geometric mean of the eigenvalues are considered as independent Gaussian random variables such that their cumulative distribution functions (CDFs) are approximated by a univariate Gaussian distribution function for any number of cooperating secondary users and received samples. The approximation approach is based on the calculation of exact analytical moments of the largest eigenvalue and the Geometric mean of the eigenvalues of the received covariance matrix. The decision threshold has been calculated by exploiting the CDF of the ratio of two Gaussian distributed random variables. In this context, we exchange the analytical moments of the two random variables with the moments of the Gaussian distribution function. The performance of the detector is compared with the performance of the energy detector and eigenvalue ratio detector. Analytical and simulation results show that our newly proposed detector yields considerable performance advantage in realistic spectrum sensing scenarios. Moreover, our results based on proposed approximation approach are in perfect agreement with the empirical results. © 2011 IEEE.

  13. The global diversion of pharmaceutical drugs. India: the third largest illicit opium producer?

    Science.gov (United States)

    Paoli, Letizia; Greenfield, Victoria A; Charles, Molly; Reuter, Peter

    2009-03-01

    This paper explores India's role in the world illicit opiate market, particularly its role as a producer. India, a major illicit opiate consumer, is also the sole licensed exporter of raw opium: this unique status may be enabling substantial diversion to the illicit market. Participant observation and interviews were carried out at eight different sites. Information was also drawn from all standard secondary sources and the analysis of about 180 drug-related criminal proceedings reviewed by Indian High Courts and the Supreme Court from 1985 to 2001. Diversion from licit opium production takes place on such a large scale that India may be the third largest illicit opium producer after Afghanistan and Burma. With the possible exceptions of 2005 and 2006, 200-300 tons of India's opium may be diverted yearly. After estimating India's opiate consumption on the basis of UN-reported prevalence estimates, we find that diversion from licit production might have satisfied a quarter to more than a third of India's illicit opiate demand to 2004. India is not only among the world's largest consumer of illicit opiates but also one of the largest illicit opium producers. In contrast to all other illicit producers, India owes the latter distinction not to blatantly illicit cultivation but to diversion from licit cultivation. India's experience suggests the difficulty of preventing substantial leakage, even in a relatively well-governed nation.

  14. Enzyme Molecules in Solitary Confinement

    Directory of Open Access Journals (Sweden)

    Raphaela B. Liebherr

    2014-09-01

    Full Text Available Large arrays of homogeneous microwells each defining a femtoliter volume are a versatile platform for monitoring the substrate turnover of many individual enzyme molecules in parallel. The high degree of parallelization enables the analysis of a statistically representative enzyme population. Enclosing individual enzyme molecules in microwells does not require any surface immobilization step and enables the kinetic investigation of enzymes free in solution. This review describes various microwell array formats and explores their applications for the detection and investigation of single enzyme molecules. The development of new fabrication techniques and sensitive detection methods drives the field of single molecule enzymology. Here, we introduce recent progress in single enzyme molecule analysis in microwell arrays and discuss the challenges and opportunities.

  15. DGAT enzymes and triacylglycerol biosynthesis

    Science.gov (United States)

    Yen, Chi-Liang Eric; Stone, Scot J.; Koliwad, Suneil; Harris, Charles; Farese, Robert V.

    2008-01-01

    Triacylglycerols (triglycerides) (TGs) are the major storage molecules of metabolic energy and FAs in most living organisms. Excessive accumulation of TGs, however, is associated with human diseases, such as obesity, diabetes mellitus, and steatohepatitis. The final and the only committed step in the biosynthesis of TGs is catalyzed by acyl-CoA:diacylglycerol acyltransferase (DGAT) enzymes. The genes encoding two DGAT enzymes, DGAT1 and DGAT2, were identified in the past decade, and the use of molecular tools, including mice deficient in either enzyme, has shed light on their functions. Although DGAT enzymes are involved in TG synthesis, they have distinct protein sequences and differ in their biochemical, cellular, and physiological functions. Both enzymes may be useful as therapeutic targets for diseases. Here we review the current knowledge of DGAT enzymes, focusing on new advances since the cloning of their genes, including possible roles in human health and diseases. PMID:18757836

  16. Enzyme stabilization for pesticide degradation

    Energy Technology Data Exchange (ETDEWEB)

    Rivers, D.B.; Frazer, F.R. III; Mason, D.W.; Tice, T.R.

    1988-01-01

    Enzymes offer inherent advantages and limitations as active components of formulations used to decontaminate soil and equipment contaminated with toxic materials such as pesticides. Because of the catalytic nature of enzymes, each molecule of enzyme has the potential to destroy countless molecules of a contaminating toxic compound. This degradation takes place under mild environmental conditions of pH, temperature, pressure, and solvent. The basic limitation of enzymes is their degree of stability during storage and application conditions. Stabilizing methods such as the use of additives, covalent crosslinking, covalent attachment, gel entrapment, and microencapsulation have been directed developing an enzyme preparation that is stable under extremes of pH, temperature, and exposure to organic solvents. Initial studies were conducted using the model enzymes subtilisin and horseradish peroxidase.

  17. Direct comparison of enzyme histochemical and immunohistochemical methods to localize an enzyme

    NARCIS (Netherlands)

    van Noorden, Cornelis J. F.

    2002-01-01

    Immunohistochemical localization of enzymes is compared directly with localization of enzyme activity with (catalytic) enzyme histochemical methods. The two approaches demonstrate principally different aspects of an enzyme. The immunohistochemical method localizes the enzyme protein whether it is

  18. Enzyme Mimics: Advances and Applications.

    Science.gov (United States)

    Kuah, Evelyn; Toh, Seraphina; Yee, Jessica; Ma, Qian; Gao, Zhiqiang

    2016-06-13

    Enzyme mimics or artificial enzymes are a class of catalysts that have been actively pursued for decades and have heralded much interest as potentially viable alternatives to natural enzymes. Aside from having catalytic activities similar to their natural counterparts, enzyme mimics have the desired advantages of tunable structures and catalytic efficiencies, excellent tolerance to experimental conditions, lower cost, and purely synthetic routes to their preparation. Although still in the midst of development, impressive advances have already been made. Enzyme mimics have shown immense potential in the catalysis of a wide range of chemical and biological reactions, the development of chemical and biological sensing and anti-biofouling systems, and the production of pharmaceuticals and clean fuels. This Review concerns the development of various types of enzyme mimics, namely polymeric and dendrimeric, supramolecular, nanoparticulate and proteinic enzyme mimics, with an emphasis on their synthesis, catalytic properties and technical applications. It provides an introduction to enzyme mimics and a comprehensive summary of the advances and current standings of their applications, and seeks to inspire researchers to perfect the design and synthesis of enzyme mimics and to tailor their functionality for a much wider range of applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Phage lytic enzymes: a history.

    Science.gov (United States)

    Trudil, David

    2015-02-01

    There are many recent studies regarding the efficacy of bacteriophage-related lytic enzymes: the enzymes of 'bacteria-eaters' or viruses that infect bacteria. By degrading the cell wall of the targeted bacteria, these lytic enzymes have been shown to efficiently lyse Gram-positive bacteria without affecting normal flora and non-related bacteria. Recent studies have suggested approaches for lysing Gram-negative bacteria as well (Briersa Y, et al., 2014). These enzymes include: phage-lysozyme, endolysin, lysozyme, lysin, phage lysin, phage lytic enzymes, phageassociated enzymes, enzybiotics, muralysin, muramidase, virolysin and designations such as Ply, PAE and others. Bacteriophages are viruses that kill bacteria, do not contribute to antimicrobial resistance, are easy to develop, inexpensive to manufacture and safe for humans, animals and the environment. The current focus on lytic enzymes has been on their use as anti-infectives in humans and more recently in agricultural research models. The initial translational application of lytic enzymes, however, was not associated with treating or preventing a specific disease but rather as an extraction method to be incorporated in a rapid bacterial detection assay (Bernstein D, 1997).The current review traces the translational history of phage lytic enzymes-from their initial discovery in 1986 for the rapid detection of group A streptococcus in clinical specimens to evolving applications in the detection and prevention of disease in humans and in agriculture.

  20. [The rise of enzyme engineering in China].

    Science.gov (United States)

    Li, Gaoxiang

    2015-06-01

    Enzyme engineering is an important part of the modern biotechnology. Industrial biocatalysis is considered the third wave of biotechnology following pharmaceutical and agricultural waves. In 25 years, China has made a mighty advances in enzyme engineering research. This review focuses on enzyme genomics, enzyme proteomics, biosynthesis, microbial conversion and biosensors in the Chinese enzyme engineering symposiums and advances in enzyme preparation industry in China.

  1. The metagenome-derived enzymes LipS and LipT increase the diversity of known lipases.

    Directory of Open Access Journals (Sweden)

    Jennifer Chow

    Full Text Available Triacylglycerol lipases (EC 3.1.1.3 catalyze both hydrolysis and synthesis reactions with a broad spectrum of substrates rendering them especially suitable for many biotechnological applications. Most lipases used today originate from mesophilic organisms and are susceptible to thermal denaturation whereas only few possess high thermotolerance. Here, we report on the identification and characterization of two novel thermostable bacterial lipases identified by functional metagenomic screenings. Metagenomic libraries were constructed from enrichment cultures maintained at 65 to 75 °C and screened resulting in the identification of initially 10 clones with lipolytic activities. Subsequently, two ORFs were identified encoding lipases, LipS and LipT. Comparative sequence analyses suggested that both enzymes are members of novel lipase families. LipS is a 30.2 kDa protein and revealed a half-life of 48 h at 70 °C. The lipT gene encoded for a multimeric enzyme with a half-life of 3 h at 70 °C. LipS had an optimum temperature at 70 °C and LipT at 75 °C. Both enzymes catalyzed hydrolysis of long-chain (C(12 and C(14 fatty acid esters and additionally hydrolyzed a number of industry-relevant substrates. LipS was highly specific for (R-ibuprofen-phenyl ester with an enantiomeric excess (ee of 99%. Furthermore, LipS was able to synthesize 1-propyl laurate and 1-tetradecyl myristate at 70 °C with rates similar to those of the lipase CalB from Candida antarctica. LipS represents the first example of a thermostable metagenome-derived lipase with significant synthesis activities. Its X-ray structure was solved with a resolution of 1.99 Å revealing an unusually compact lid structure.

  2. Enzyme structure, enzyme function and allozyme diversity in ...

    African Journals Online (AJOL)

    In estimates of population genetic diversity based on allozyme heterozygosity, some enzymes are regularly more variable than others. Evolutionary theory suggests that functionally less important molecules, or parts of molecules, evolve more rapidly than more important ones; the latter enzymes should then theoretically be ...

  3. Computational enzyme design: transitioning from catalytic proteins to enzymes.

    Science.gov (United States)

    Mak, Wai Shun; Siegel, Justin B

    2014-08-01

    The widespread interest in enzymes stem from their ability to catalyze chemical reactions under mild and ecologically friendly conditions with unparalleled catalytic proficiencies. While thousands of naturally occurring enzymes have been identified and characterized, there are still numerous important applications for which there are no biological catalysts capable of performing the desired chemical transformation. In order to engineer enzymes for which there is no natural starting point, efforts using a combination of quantum chemistry and force-field based protein molecular modeling have led to the design of novel proteins capable of catalyzing chemical reactions not catalyzed by naturally occurring enzymes. Here we discuss the current status and potential avenues to pursue as the field of computational enzyme design moves forward. Published by Elsevier Ltd.

  4. Immobilized enzymes: understanding enzyme - surface interactions at the molecular level.

    Science.gov (United States)

    Hoarau, Marie; Badieyan, Somayesadat; Marsh, E Neil G

    2017-11-22

    Enzymes immobilized on solid supports have important and industrial and medical applications. However, their uses are limited by the significant reductions in activity and stability that often accompany the immobilization process. Here we review recent advances in our understanding of the molecular level interactions between proteins and supporting surfaces that contribute to changes in stability and activity. This understanding has been facilitated by the application of various surface-sensitive spectroscopic techniques that allow the structure and orientation of enzymes at the solid/liquid interface to be probed, often with monolayer sensitivity. An appreciation of the molecular interactions between enzyme and surface support has allowed the surface chemistry and method of enzyme attachement to be fine-tuned such that activity and stability can be greatly enhanced. These advances suggest that a much wider variety of enzymes may eventually be amenable to immobilization as green catalysts.

  5. Stability of Enzymes in Granular Enzyme Products for Laundry Detergents

    DEFF Research Database (Denmark)

    Biran, Suzan; Bach, Poul; Simonsen, Ole

    Enzymes have long been of interest to the detergent industry due to their ability to improve the cleaning efficiency of synthetic detergents, contribute to shortening washing times, and reduce energy and water consumption, provision of environmentally friendlier wash water effluents and fabric care....... However, incorporating enzymes in detergent formulations gives rise to numerous practical problems due to their incompatibility with and stability against various detergent components. In powdered detergent formulations, these issues can be partly overcome by physically isolating the enzymes in separate...... particles. However, enzymes may loose a significant part of their activity over a time period of several weeks. Possible causes of inactivation of enzymes in a granule may be related to the release of hydrogen peroxide from the bleaching chemicals in a moisture-containing atmosphere, humidity, autolysis...

  6. Enzymes in Human Milk.

    Science.gov (United States)

    Dallas, David C; German, J Bruce

    2017-01-01

    Milk proteins are a complex and diverse source of biological activities. Beyond their function, intact milk proteins also act as carriers of encrypted functional sequences that, when released as peptides, exert biological functions, including antimicrobial and immunomodulatory activity, which could contribute to the infant's competitive success. Research has now revealed that the release of these functional peptides begins within the mammary gland itself. A complex array of proteases produced in mother's milk has been shown to be active in the milk, releasing these peptides. Moreover, our recent research demonstrates that these milk proteases continue to digest milk proteins within the infant's stomach, possibly even to a larger extent than the infant's own proteases. As the neonate has relatively low digestive capacity, the activity of milk proteases in the infant may provide important assistance to digesting milk proteins. The coordinated release of these encrypted sequences is accomplished by selective proteolytic action provided by an array of native milk proteases and infant-produced enzymes. The task for scientists is now to discover the selective advantages of this protein-protease-based peptide release system. © 2017 Nestec Ltd., Vevey/S. Karger AG, Basel.

  7. Digestive enzymes of some earthworms.

    Science.gov (United States)

    Mishra, P C; Dash, M C

    1980-10-15

    4 species of tropical earthworms differed with regard to enzyme activity. The maximum activity of protease and of cellulase occurred in the posterior region of the gut of the earthworms. On the average Octochaetona surensis shows maximum activity and Drawida calebi shows minimum activity for all the enzymes studied.

  8. Photoreactivating enzyme from Escherichia coli

    International Nuclear Information System (INIS)

    Snapka, R.M.; Fuselier, C.O.

    1977-01-01

    Escherichia coli photoreactivating enzyme (PRE) has been purified in large amounts from an E.coli strain lysogenic for a defective lambda bacteriophage carrying the phr gene. The resulting enzyme had a pH optimum of 7.2 and an ionic strength optimum of 0.18. It consisted of an apoprotein and cofactor, both of which were necessary for catalytic activity. The apoprotein had a monomer molecular weight of 35,200 and showed stable aggregates under denaturing conditions. The amino acid analysis of the E.coli enzyme was very similar to that of the photoreactivating enzyme from orchid seedlings (Cattelya aurantiaca). Both had arginine at the amino terminus. The cofactor, like the holoenzyme, showed absorption, magnetic circular dichroism, and emission properties indicative of an adenine moiety. Although the isolated enzyme had an action spectrum which peaked at about 360 nm, neither the cofactor, apoenzyme nor holoenzyme showed any detectable absorption between 300 and 400 nm. (author)

  9. Positron emitter labeled enzyme inhibitors

    International Nuclear Information System (INIS)

    Fowler, J.S.; MacGregor, R.R.; Wolf, A.P.; Langstrom, B.

    1990-01-01

    This invention involves a new strategy for imagining and mapping enzyme activity in the living human and animal body using positron emitter-labeled suicide enzyme inactivators or inhibitors which become covalently bound to the enzyme as a result of enzymatic catalysis. Two such suicide inactivators for monoamine oxidase have been labeled with carbon-11 and used to map the enzyme subtypes in the living human and animal body using PET. By using positron emission tomography to image the distribution of radioactivity produced by the body penetrating radiation emitted by carbon-11, a map of functionally active monoamine oxidase activity is obtained. Clorgyline and L-deprenyl are suicide enzyme inhibitors and irreversibly inhibit monoamine oxidase. When these inhibitors are labeled with carbon-11 they provide selective probes for monoamine oxidase localization and reactivity in vivo using positron emission tomography

  10. Photoreactivating enzyme from Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Snapka, R M; Fuselier, C O [California Univ., Irvine (USA)

    1977-05-01

    Escherichia coli photoreactivating enzyme (PRE) has been purified in large amounts from an E.coli strain lysogenic for a defective lambda bacteriophage carrying the phr gene. The resulting enzyme had a pH optimum of 7.2 and an ionic strength optimum of 0.18. It consisted of an apoprotein and cofactor, both of which were necessary for catalytic activity. The apoprotein had a monomer molecular weight of 35,200 and showed stable aggregates under denaturing conditions. The amino acid analysis of the E.coli enzyme was very similar to that of the photoreactivating enzyme from orchid seedlings (Cattelya aurantiaca). Both had arginine at the amino terminus. The cofactor, like the holoenzyme, showed absorption, magnetic circular dichroism, and emission properties indicative of an adenine moiety. Although the isolated enzyme had an action spectrum which peaked at about 360 nm, neither the cofactor, apoenzyme nor holoenzyme showed any detectable absorption between 300 and 400 nm.

  11. THE EVOLUTION OF THE WORLD’S LARGEST AUTOMAKERS IN THE PERIOD 2013-2014

    Directory of Open Access Journals (Sweden)

    Sorin-George TOMA

    2015-04-01

    Full Text Available The automotive industry has always represented an economic engine for many countries. It is dealing with the design, development, manufacture, marketing, and sale of the motor vehicles. Nowadays, this industry is full of intense competition between big auto groups fighting for higher profits and larger market shares. The key players in the automotive market are operating at a global scale in a highly competitive environment. In the last years, Toyota Motor and Volkswagen Group have proved to be the main competitors. The aim of our paper is to analyze the evolution of the world’s largest automakers in the period 2013-2014. The research type is literature review.

  12. Europe's largest solar thermal power plant. [200 kw thermal output supplemented by two 10-kw windmills

    Energy Technology Data Exchange (ETDEWEB)

    Bossel, U

    1976-03-01

    An overview is given over the solar heating plant which has recently been commissioned in the Camargue (France). This is the largest plant in Europe, with a mean heat output of about 200 kW, for the production of thermal energy from solar energy. The plant consists of 108 parabolic collectors (200 sq. metres) and 48 flat collectors (110 sq. metres). Two windmills with outputs of 10 kW each complete the system. The heat energy produced by the solar collectors is given up to 3 different stores, which in turn are connected to various consumers.

  13. OBJECT TRACKING WITH ROTATION-INVARIANT LARGEST DIFFERENCE INDEXED LOCAL TERNARY PATTERN

    Directory of Open Access Journals (Sweden)

    J Shajeena

    2017-02-01

    Full Text Available This paper presents an ideal method for object tracking directly in the compressed domain in video sequences. An enhanced rotation-invariant image operator called Largest Difference Indexed Local Ternary Pattern (LDILTP has been proposed. The Local Ternary Pattern which worked very well in texture classification and face recognition is now extended for rotation invariant object tracking. Histogramming the LTP code makes the descriptor resistant to translation. The histogram intersection is used to find the similarity measure. This method is robust to noise and retain contrast details. The proposed scheme has been verified on various datasets and shows a commendable performance.

  14. Female urethral diverticulum presenting with acute urinary retention: Reporting the largest diverticulum with review of literature

    Directory of Open Access Journals (Sweden)

    Manas Ranjan Pradhan

    2012-01-01

    Full Text Available Female urethral diverticulum is a rare entity with diverse spectrum of clinical manifestations. It is a very rare cause of bladder outlet obstruction and should be considered as a differential diagnosis in females presenting with acute urinary retention associated with a vaginal mass. Strong clinical suspicion combined with thorough physical examination and focused radiological investigations are vital for its diagnosis. Herein we report a case of giant urethral diverticulum presenting with acute urinary retention in a young female. It was managed by excision and urethral closure, and is the largest urethral diverticulum reported till date in the literature.

  15. WISMUT AG: Past, present and future of the largest uranium producer in Europe

    International Nuclear Information System (INIS)

    Madel, J.

    1990-01-01

    The author gives a brief summary of WISMUT AG the largest uranium producer operating in Europe. The jointly owned German-Soviet company operates its production facilities in the southern part of the former German Democratic Republic. Given the new political and economic frame in Germany and the Soviet Union WISMUT AG will receive due recognition. Uranium exploration, mining, and milling activities are summarized from 1946-1989, and a summary of present activities and projections of future activities in the area of decontamination, restoration, and recultivation of present and abandoned mining and milling sites are noted. A statement of WISMUT AG's projected role in the international nuclear fuels market is made

  16. How the largest electric and gas utility companies administer public relations

    Energy Technology Data Exchange (ETDEWEB)

    Bogart, J.D.

    1979-04-12

    This article describes the findings of a survey conducted by the author in the second half of 1978 to determine the sizes of the public relations staffs of the nation's largest operating electric and gas utilities, their budgets, organizational differences, and specific functions. Common public relations issues and major public relations problems of the utilities are identified, as well as recent trends or changes in budgeting and organization. Some functional variations of public relations departments among utility companies were detected and described.

  17. Line Balancing Using Largest Candidate Rule Algorithm In A Garment Industry: A Case Study

    Directory of Open Access Journals (Sweden)

    V. P.Jaganathan

    2014-12-01

    Full Text Available The emergence of fast changes in fashion has given rise to the need to shorten production cycle times in the garment industry. As effective usage of resources has a significant effect on the productivity and efficiency of production operations, garment manufacturers are urged to utilize their resources effectively in order to meet dynamic customer demand. This paper focuses specifically on line balancing and layout modification. The aim of assembly line balance in sewing lines is to assign tasks to the workstations, so that the machines of the workstation can perform the assigned tasks with a balanced loading. Largest Candidate Rule Algorithm (LCR has been deployed in this paper.

  18. Foreign exchange risk management : how are the largest non-financial companies in Norway managing their foreign exchange rate exposure?

    OpenAIRE

    Eriksen, Krister; Wedøe, Ola

    2010-01-01

    The purpose of this thesis is to investigate how the largest non-financial companies in Norway manage their foreign exchange rate exposure. This is investigated through the use of a survey distributed to a sample the largest non-financial firms in Norway. According to our results, the largest non-financial companies in Norway have a predefined strategy for managing foreign exchange risk, which is defined by the board of directors or by the management in the organisation. The companies’ mai...

  19. Revisiting the impacts of oil price increases on monetary policy implementation in the largest oil importers

    Directory of Open Access Journals (Sweden)

    Nurtac Yildirim

    2015-06-01

    Full Text Available The aim of this paper is to test the impacts of oil price increases on monetary policy implementation in the largest oil importers. For that purpose, we estimate structural vector error correction (SVEC models to show the impacts of oil price increases on industrial production, consumer prices and immediate interest rates which are the elements of Taylor rule for the four largest oil importers (the USA, the EU, China and Japan. Our results indicate that oil price increases transmit to output and inflation and lead to fluctuations in industrial production, consumer prices and immediate interest rates which in turn influence the monetary policy stance in the following periods. The basic conclusion of research is that the channels through which oil prices affect output, inflation and interest rates should be identified by the monetary policy authorities of the USA, the EU, China and Japan. We also emphasize the importance of the determination of the optimal monetary policy framework to eliminate the negative consequences of oil price increases.

  20. Rehabilitation of the 6 largest hydropower plants in the Republic of Macedonia

    International Nuclear Information System (INIS)

    Chingoski, Vlatko; Savevski, Vasil

    2004-01-01

    In 1998, ESM (Electric Power Co. of Macedonia) received a loan from the International Bank for Reconstruction and Development (IBRD - The World bank) for the cost of the Power System Improvement Project, major part of which is the partial rehabilitation of the six largest HPPs in the Republic of Macedonia. Rehabilitation and life extension of these six largest hydro power plants is given the highest priority in the whole Power System Improvement Project mainly because these HPPs are, in general, fairly old, older than most of the thermal generation capacity and because a significant part of their equipment is wearing out, or is now obsolete with spare parts difficult to obtain. Furthermore, these plants play a vital role in the Macedonian Power System, providing peaking capacity, reserve capacity and frequency control. With the realization of this project, greater hydropower production is expected. It is also expected that HPPs will become a more vital part of the Macedonian Power System, which is also beneficial from an environmental aspect, due to greater usage of renewable energy resources in the country. (Original)

  1. Ownership structure and economic and socio-environmental disclosure in the largest Brazilian companies

    Directory of Open Access Journals (Sweden)

    Tatiana Aquino Almeida

    2016-01-01

    Full Text Available The disclosure of sustainable practices has become important in the search for competitive advantage, so as to meet the expectations of the various stakeholders. Thus, the study aims to investigate the relationship between the ownership structure and the economic and environmental voluntary disclosure in the largest Brazilian companies, analyzing ownership concentration and the identity of the controlling shareholder. For the analysis, we considered the economic, social and environmental perspectives, addressed both individually and jointly. The sample consists of 47 companies from the 100 largest public companies listed on BM&FBOVESPA, according to the magazine Exame Biggest and Best, edition 2013. The research is descriptive and quantitative, using Multiple Linear Regression for statistical analysis. The descriptive analysis of the prospects of (economic, social, environmental and sustainability disclosure showed lower average disclosure for the environmental aspect. The state control organizations stood out with the highest average in three of the four levels of disclosure: economic, social and sustainability. As regards the application of statistical analysis, the regression models were not statistically significant, indicating that, for the companies in the sample, the ownership structure does not influence the economic and socio-environmental disclosure.

  2. BAKERY ENZYMES IN CEREAL TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    Václav Koman

    2012-10-01

    Full Text Available Normal 0 21 false false false SK X-NONE X-NONE Bread is the most common and traditional food in the world. For years, enzymes such as malt and fungal alpha-amylase have been used in bread making. Due to the changes in the baking industry and the ever-increasing demand for more natural products, enzymes have gained real importance in bread-making. If an enzyme is added, it is often destroyed by the heat during the baking process. For generations, enzymes have been used for the improvement of texture and appearance, enhancement of nutritional values and generation of appealing flavours and aromas. Enzymes used in bakery industry constitute nearly one third of the market. The bakery products have undergone radical improvements in quality over the past years in terms of flavour, texture and shelf-life. The the biggest contributor for these improvementsis the usage of enzymes. Present work seeks to systematically describe bakery enzymes, their classification, benefits, usage and chemical reactions in the bread making process.doi:10.5219/193

  3. Giant basal spicule from the deep-sea glass sponge Monorhaphis chuni: synthesis of the largest bio-silica structure on Earth by silicatein

    Science.gov (United States)

    Wang, Xiao-hong; Zhang, Xue-hua; Schröder, Heinz C.; Müller, Werner E. G.

    2009-09-01

    Like all sponges (phylum Porifera), the glass sponges (Hexactinellida) are provided with an elaborate and distinct body plan, which relies on a filigree skeleton. It is constructed by an array of morphologically determined elements, the spicules. Schulze described the largest siliceous hexactinellid sponge on Earth, the up to 3 m high Monorhaphis chuni, collected during the German Deep Sea Expedition "Valdivia" (1898-1899). This species develops an equally large bio-silica structure, the giant basal spicule (3 m × 10 mm). Using these spicules as a model, one can obtain the basic knowledge on the morphology, formation, and development of silica skeletal elements. The silica matrix is composed of almost pure silica, endowing it with unusual optophysical properties, which are superior to those of man-made waveguides. Experiments suggest that the spicules function in vivo as a nonocular photoreception system. The spicules are also provided with exceptional mechanical properties. Like demosponges, the hexactinellids synthesize their silica enzymatically via the enzyme silicatein (27 kDa protein). This enzyme is located in/embedded in the silica layers. This knowledge will surely contribute to a further utilization and exploration of silica in biomaterial/biomedical science.

  4. [Automated analyzer of enzyme immunoassay].

    Science.gov (United States)

    Osawa, S

    1995-09-01

    Automated analyzers for enzyme immunoassay can be classified by several points of view: the kind of labeled antibodies or enzymes, detection methods, the number of tests per unit time, analytical time and speed per run. In practice, it is important for us consider the several points such as detection limits, the number of tests per unit time, analytical range, and precision. Most of the automated analyzers on the market can randomly access and measure samples. I will describe the recent advance of automated analyzers reviewing their labeling antibodies and enzymes, the detection methods, the number of test per unit time and analytical time and speed per test.

  5. Multi-enzyme Process Modeling

    DEFF Research Database (Denmark)

    Andrade Santacoloma, Paloma de Gracia

    are affected (in a positive or negative way) by the presence of the other enzymes and compounds in the media. In this thesis the concept of multi-enzyme in-pot term is adopted for processes that are carried out by the combination of enzymes in a single reactor and implemented at pilot or industrial scale...... features of the process and provides the information required to structure the process model by using a step-by-step procedure with the required tools and methods. In this way, this framework increases efficiency of the model development process with respect to time and resources needed (fast and effective....... In this way the model parameters that drives the main dynamic behavior can be identified and thus a better understanding of this type of processes. In order to develop, test and verify the methodology, three case studies were selected, specifically the bi-enzyme process for the production of lactobionic acid...

  6. PIXE analysis of Zn enzymes

    International Nuclear Information System (INIS)

    Solis, C.; Oliver, A.; Andrade, E.; Ruvalcaba-Sil, J.L.; Romero, I.; Celis, H.

    1999-01-01

    Zinc is a necessary component in the action and structural stability of many enzymes. Some of them are well characterized, but in others, Zn stoichiometry and its association is not known. PIXE has been proven to be a suitable technique for analyzing metallic proteins embedded in electrophoresis gels. In this study, PIXE has been used to investigate the Zn content of enzymes that are known to carry Zn atoms. These include the carbonic anhydrase, an enzyme well characterized by other methods and the cytoplasmic pyrophosphatase of Rhodospirillum rubrum that is known to require Zn to be stable but not how many metal ions are involved or how they are bound to the enzyme. Native proteins have been purified by polyacrylamide gel electrophoresis and direct identification and quantification of Zn in the gel bands was performed with an external proton beam of 3.7 MeV energy

  7. GRE Enzymes for Vector Analysis

    Data.gov (United States)

    U.S. Environmental Protection Agency — Microbial enzyme data that were collected during the 2004-2006 EMAP-GRE program. These data were then used by Moorhead et al (2016) in their ecoenzyme vector...

  8. Watching Individual Enzymes at Work

    Science.gov (United States)

    Blank, Kerstin; Rocha, Susana; De Cremer, Gert; Roeffaers, Maarten B. J.; Uji-i, Hiroshi; Hofkens, Johan

    Single-molecule fluorescence experiments are a powerful tool to analyze reaction mechanisms of enzymes. Because of their unique potential to detect heterogeneities in space and time, they have provided unprecedented insights into the nature and mechanisms of conformational changes related to the catalytic reaction. The most important finding from experiments with single enzymes is the generally observed phenomenon that the catalytic rate constants fluctuate over time (dynamic disorder). These fluctuations originate from conformational changes occurring on time scales, which are similar to or slower than that of the catalytic reaction. Here, we summarize experiments with enzymes that show dynamic disorder and introduce new experimental strategies showing how single-molecule fluorescence experiments can be applied to address other open questions in medical and industrial enzymology, such as enzyme inactivation processes, reactant transfer in cascade reactions, and the mechanisms of interfacial catalysis.

  9. Photosynthetic fuel for heterologous enzymes

    DEFF Research Database (Denmark)

    Mellor, Silas Busck; Vavitsas, Konstantinos; Nielsen, Agnieszka Janina Zygadlo

    2017-01-01

    of reducing power. Recent work on the metabolic engineering of photosynthetic organisms has shown that the electron carriers such as ferredoxin and flavodoxin can be used to couple heterologous enzymes to photosynthetic reducing power. Because these proteins have a plethora of interaction partners and rely...... on electrostatically steered complex formation, they form productive electron transfer complexes with non-native enzymes. A handful of examples demonstrate channeling of photosynthetic electrons to drive the activity of heterologous enzymes, and these focus mainly on hydrogenases and cytochrome P450s. However......, competition from native pathways and inefficient electron transfer rates present major obstacles, which limit the productivity of heterologous reactions coupled to photosynthesis. We discuss specific approaches to address these bottlenecks and ensure high productivity of such enzymes in a photosynthetic...

  10. Field Note: Threatening Tonle Sap: Challenges for Southeast-Asia’s largest Freshwater Lake

    Directory of Open Access Journals (Sweden)

    Kuenzer, Claudia

    2013-09-01

    Full Text Available The Tonle Sap ecosystem in Cambodia is Southeast Asia’s largest freshwater lake; strongly impacted by the Mekong river flood pulse. The lake is home to exceptional biodiversity, and rural communities living in free floating villages on the lake and on its shores. The fragile niche ecosystems as well as the rural livelihoods of Tonle Sap are under severe threat. Overfishing, illegal wood harvesting, further resource exploitation, and water quality deterioration all impact the stability of the socio-ecological system of Tonle Sap. At the same time, expected flood pulse changes due to regulatory measures in the context of hydropower development upstream on the Mekong are a severe threat for Tonle Sap’s ecosystem stability. The area needs to shift into the focus of attention of national and international re-searchers, stakeholders, and decision makers, to find suitable pathways for a future sustainable development of this unique and pristine region.

  11. Fifteen Years of Operation at NASA's National Transonic Facility with the World's Largest Adjustable Speed Drive

    Science.gov (United States)

    Sydnor, George H.; Bhatia, Ram; Krattiger, Hansueli; Mylius, Justus; Schafer, D.

    2012-01-01

    In September 1995, a project was initiated to replace the existing drive line at NASA's most unique transonic wind tunnel, the National Transonic Facility (NTF), with a single 101 MW synchronous motor driven by a Load Commutated Inverter (LCI). This Adjustable Speed Drive (ASD) system also included a custom four-winding transformer, harmonic filter, exciter, switch gear, control system, and feeder cable. The complete system requirements and design details have previously been presented and published [1], as well as the commissioning and acceptance test results [2]. The NTF was returned to service in December 1997 with the new drive system powering the fan. Today, this installation still represents the world s largest horizontal single motor/drive combination. This paper describes some significant events that occurred with the drive system during the first 15 years of service. These noteworthy issues are analyzed and root causes presented. Improvements that have substantially increased the long term viability of the system are given.

  12. Mauna Loa--history, hazards and risk of living with the world's largest volcano

    Science.gov (United States)

    Trusdell, Frank A.

    2012-01-01

    Mauna Loa on the Island Hawaiʻi is the world’s largest volcano. People residing on its flanks face many hazards that come with living on or near an active volcano, including lava flows, explosive eruptions, volcanic smog, damaging earthquakes, and local tsunami (giant seawaves). The County of Hawaiʻi (Island of Hawaiʻi) is the fastest growing County in the State of Hawaii. Its expanding population and increasing development mean that risk from volcano hazards will continue to grow. U.S. Geological Survey (USGS) scientists at the Hawaiian Volcano Observatory (HVO) closely monitor and study Mauna Loa Volcano to enable timely warning of hazardous activity and help protect lives and property.

  13. Approaching the largest ‘API’: extracting information from the Internet with Python

    Directory of Open Access Journals (Sweden)

    Jonathan E. Germann

    2018-02-01

    Full Text Available This article explores the need for libraries to algorithmically access and manipulate the world’s largest API: the Internet. The billions of pages on the ‘Internet API’ (HTTP, HTML, CSS, XPath, DOM, etc. are easily accessible and manipulable. Libraries can assist in creating meaning through the datafication of information on the world wide web. Because most information is created for human consumption, some programming is required for automated extraction. Python is an easy-to-learn programming language with extensive packages and community support for web page automation. Four packages (Urllib, Selenium, BeautifulSoup, Scrapy in Python can automate almost any web page for all sized projects. An example warrant data project is explained to illustrate how well Python packages can manipulate web pages to create meaning through assembling custom datasets.

  14. Quicksort, largest bucket, and min-wise hashing with limited independence

    DEFF Research Database (Denmark)

    Knudsen, Mathias Bæk Tejs; Stöckel, Morten

    2015-01-01

    Randomized algorithms and data structures are often analyzed under the assumption of access to a perfect source of randomness. The most fundamental metric used to measure how “random” a hash function or a random number generator is, is its independence: a sequence of random variables is said...... to be k-independent if every variable is uniform and every size k subset is independent. In this paper we consider three classic algorithms under limited independence. Besides the theoretical interest in removing the unrealistic assumption of full independence, the work is motivated by lower independence...... being more practical. We provide new bounds for randomized quicksort, min-wise hashing and largest bucket size under limited independence. Our results can be summarized as follows. Randomized Quicksort. When pivot elements are computed using a 5-independent hash function, Karloff and Raghavan, J.ACM’93...

  15. Contamination Control Assessment of the World's Largest Space Environment Simulation Chamber

    Science.gov (United States)

    Snyder, Aaron; Henry, Michael W.; Grisnik, Stanley P.; Sinclair, Stephen M.

    2012-01-01

    The Space Power Facility s thermal vacuum test chamber is the largest chamber in the world capable of providing an environment for space simulation. To improve performance and meet stringent requirements of a wide customer base, significant modifications were made to the vacuum chamber. These include major changes to the vacuum system and numerous enhancements to the chamber s unique polar crane, with a goal of providing high cleanliness levels. The significance of these changes and modifications are discussed in this paper. In addition, the composition and arrangement of the pumping system and its impact on molecular back-streaming are discussed in detail. Molecular contamination measurements obtained with a TQCM and witness wafers during two recent integrated system tests of the chamber are presented and discussed. Finally, a concluding remarks section is presented.

  16. What could we learn about high energy particle physics from cosmological observations at largest spatial scales ?

    Directory of Open Access Journals (Sweden)

    Gorbunov Dmitry

    2017-01-01

    Full Text Available The very well known example of cosmology testing particle physics is the number of relativistic particles (photons and three active neutrinos within the Standard Model at primordial nucleosynthesis. These days the earliest moment we can hope to probe with present cosmological data is the early time inflation. The particle physics conditions there and now are different because of different energy scales and different values of the scalar fields, that usually prohibits a reliable connection between the particle physics parameters at the two interesting epochs. The physics at the highest energy scales may be probed with observations at the largest spatial scales (just somewhat smaller than the size of the visible Universe. However, we are not (yet ready to make the tests realistic, because of lack of a self-consistent theoretical description of the presently favorite cosmological models to be valid right after inflation.

  17. The role and attributes of entrepreneurs at South Africa´s largest arts festival

    Directory of Open Access Journals (Sweden)

    E. Jonker

    2009-01-01

    Full Text Available The Klein Karoo National Arts Festival (KKNK in Oudtshoorn, South Africa, is the largest arts festival in South Africa. The purpose of this research was to determine the attributes and role of the entrepreneurs at the Klein Karoo National Arts Festival. This was done by means of a questionnaire survey (N=249. After data capturing was completed, two factor analyses were conducted. The first factor analysis revealed six factors (entrepreneurial attributes, namely organisational skills, resourcefulness, self-edification, explorative, acquired skill and drive, of which resourcefulness had the highest mean value. The second factor analysis identified the role of entrepreneurs at KKNK and revealed three primary roles, namely festival promotion, product promotion and income generation, of which product promotion had the highest mean value. This is the first time that the roles of entrepreneurs at festivals were investigated in South Africa.

  18. EVALUATION OF E-RECRUITMENT LEVEL AMONG THE LARGEST COMPANIES IN POLAND - PROJECT OF RESEARCH

    Directory of Open Access Journals (Sweden)

    Dorota Buchnowska

    2015-12-01

    Full Text Available The changes taking place in the labor market cause that it is increasingly difficult to recruit employees with the right skills and competencies to companies. To reach the right candidates, they use modern IT solutions, such as ATS (Applicant Tracking System, which are supporting the processes of recruitment. Among others, they enable the publication of job offers on the Internet - on corporate websites, job portals and business social networking services - and apply for jobs online through these channels. This article pre-sents the evolution of the use of the Internet, and particularly the social media, in the recruitment process and presents a projekt of comprehensive research, which aims is to analyze and evaluate of the level of development of e-recruitment in Poland among largest companies.

  19. Damage and protection cost curves for coastal floods within the 600 largest European cities

    Science.gov (United States)

    Prahl, Boris F.; Boettle, Markus; Costa, Luís; Kropp, Jürgen P.; Rybski, Diego

    2018-01-01

    The economic assessment of the impacts of storm surges and sea-level rise in coastal cities requires high-level information on the damage and protection costs associated with varying flood heights. We provide a systematically and consistently calculated dataset of macroscale damage and protection cost curves for the 600 largest European coastal cities opening the perspective for a wide range of applications. Offering the first comprehensive dataset to include the costs of dike protection, we provide the underpinning information to run comparative assessments of costs and benefits of coastal adaptation. Aggregate cost curves for coastal flooding at the city-level are commonly regarded as by-products of impact assessments and are generally not published as a standalone dataset. Hence, our work also aims at initiating a more critical discussion on the availability and derivation of cost curves. PMID:29557944

  20. Using largest Lyapunov exponent to confirm the intrinsic stability of boiling water reactors

    International Nuclear Information System (INIS)

    Gavilian-Moreno, Carlos; Espinosa-Paredes, Gilberto

    2016-01-01

    The aim of this paper is the study of instability state of boiling water reactors with a method based in largest Lyapunov exponents (LLEs). Detecting the presence of chaos in a dynamical system is an important problem that is solved by measuring the LLE. Lyapunov exponents quantify the exponential divergence of initially close state-space trajectories and estimate the amount of chaos in a system. This method was applied to a set of signals from several nuclear power plant (NPP) reactors under commercial operating conditions that experienced instabilities events, apparently each of a different nature. Laguna Verde and Forsmark NPPs with in-phase instabilities, and Cofrentes NPP with out-of-phases instability. This study presents the results of intrinsic instability in the boiling water reactors of three NPPs. In the analyzed cases the limit cycle was not reached, which implies that the point of equilibrium exerts influence and attraction on system evolution

  1. Using largest Lyapunov exponent to confirm the intrinsic stability of boiling water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Gavilian-Moreno, Carlos [Iberdrola Generacion, S.A., Cofrentes Nuclear Power Plant, Project Engineering Department, Paraje le Plano S/N, Valencia (Spain); Espinosa-Paredes, Gilberto [Area de ingeniera en Recursos Energeticos, Universidad Autonoma Metropolitana-Iztapalapa, Mexico city (Mexico)

    2016-04-15

    The aim of this paper is the study of instability state of boiling water reactors with a method based in largest Lyapunov exponents (LLEs). Detecting the presence of chaos in a dynamical system is an important problem that is solved by measuring the LLE. Lyapunov exponents quantify the exponential divergence of initially close state-space trajectories and estimate the amount of chaos in a system. This method was applied to a set of signals from several nuclear power plant (NPP) reactors under commercial operating conditions that experienced instabilities events, apparently each of a different nature. Laguna Verde and Forsmark NPPs with in-phase instabilities, and Cofrentes NPP with out-of-phases instability. This study presents the results of intrinsic instability in the boiling water reactors of three NPPs. In the analyzed cases the limit cycle was not reached, which implies that the point of equilibrium exerts influence and attraction on system evolution.

  2. World's largest off-road tires to be recycled

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2005-07-01

    Suncor Energy is the first company in Canada to use a new technology designed uniquely for tire recycling at oil sand facilities. The technology is owned by CuttingEdge Tire Recycling, a partnership between Denesoline Environmental Limited Partnership and Beaver Environmental Rubber Technologies Limited. Suncor has supported the development of this Aboriginal-owned and operated business by offering land, electricity, diesel fuel and stockpiles of used truck tires from its oil sand mining activities. These tires are the largest off-road tires in the world. In this new technology, tires that are worn-out through oil sand mining are shredded in a portable shredder before being recycled for subsequent use by the Alberta Recycling Management Association. 1 fig.

  3. Enhanced natural radiation exposure enhanced by human activity: the largest contributor to the Chinese population dose

    International Nuclear Information System (INIS)

    Pan Ziqiang; Liu Yanyang

    2011-01-01

    For the radiation exposure caused by human activities, the enhanced natural radiation exposure is the largest contributor to Chinese population dose. This problem has attracted social attention in recent years. Efforts have been made in several fields, such as radon indoors and in workplace, environmental problems associated with NORMs, occupational radiation hazards of non-uranium mine, and radiation dose evaluation for energy chain, but there are still many problems to be solved. In order to protect the health of workers and the public, while ensuring industrial production and economic development, it is also necessary to continue to strengthen research in all aspects above mentioned, and gradually promote the control of natural radiation exposure enhanced by human activities. (authors)

  4. A marine heatwave drives massive losses from the world’s largest seagrass carbon stocks

    KAUST Repository

    Arias-Ortiz, A.

    2018-03-29

    Seagrass ecosystems contain globally significant organic carbon (C) stocks. However, climate change and increasing frequency of extreme events threaten their preservation. Shark Bay, Western Australia, has the largest C stock reported for a seagrass ecosystem, containing up to 1.3% of the total C stored within the top metre of seagrass sediments worldwide. On the basis of field studies and satellite imagery, we estimate that 36% of Shark Bay’s seagrass meadows were damaged following a marine heatwave in 2010/2011. Assuming that 10 to 50% of the seagrass sediment C stock was exposed to oxic conditions after disturbance, between 2 and 9 Tg CO could have been released to the atmosphere during the following three years, increasing emissions from land-use change in Australia by 4–21% per annum. With heatwaves predicted to increase with further climate warming, conservation of seagrass ecosystems is essential to avoid adverse feedbacks on the climate system.

  5. Damage and protection cost curves for coastal floods within the 600 largest European cities

    Science.gov (United States)

    Prahl, Boris F.; Boettle, Markus; Costa, Luís; Kropp, Jürgen P.; Rybski, Diego

    2018-03-01

    The economic assessment of the impacts of storm surges and sea-level rise in coastal cities requires high-level information on the damage and protection costs associated with varying flood heights. We provide a systematically and consistently calculated dataset of macroscale damage and protection cost curves for the 600 largest European coastal cities opening the perspective for a wide range of applications. Offering the first comprehensive dataset to include the costs of dike protection, we provide the underpinning information to run comparative assessments of costs and benefits of coastal adaptation. Aggregate cost curves for coastal flooding at the city-level are commonly regarded as by-products of impact assessments and are generally not published as a standalone dataset. Hence, our work also aims at initiating a more critical discussion on the availability and derivation of cost curves.

  6. The largest deep-ocean silicic volcanic eruption of the past century.

    Science.gov (United States)

    Carey, Rebecca; Soule, S Adam; Manga, Michael; White, James; McPhie, Jocelyn; Wysoczanski, Richard; Jutzeler, Martin; Tani, Kenichiro; Yoerger, Dana; Fornari, Daniel; Caratori-Tontini, Fabio; Houghton, Bruce; Mitchell, Samuel; Ikegami, Fumihiko; Conway, Chris; Murch, Arran; Fauria, Kristen; Jones, Meghan; Cahalan, Ryan; McKenzie, Warren

    2018-01-01

    The 2012 submarine eruption of Havre volcano in the Kermadec arc, New Zealand, is the largest deep-ocean eruption in history and one of very few recorded submarine eruptions involving rhyolite magma. It was recognized from a gigantic 400-km 2 pumice raft seen in satellite imagery, but the complexity of this event was concealed beneath the sea surface. Mapping, observations, and sampling by submersibles have provided an exceptionally high fidelity record of the seafloor products, which included lava sourced from 14 vents at water depths of 900 to 1220 m, and fragmental deposits including giant pumice clasts up to 9 m in diameter. Most (>75%) of the total erupted volume was partitioned into the pumice raft and transported far from the volcano. The geological record on submarine volcanic edifices in volcanic arcs does not faithfully archive eruption size or magma production.

  7. A general scaling law reveals why the largest animals are not the fastest.

    Science.gov (United States)

    Hirt, Myriam R; Jetz, Walter; Rall, Björn C; Brose, Ulrich

    2017-08-01

    Speed is the fundamental constraint on animal movement, yet there is no general consensus on the determinants of maximum speed itself. Here, we provide a general scaling model of maximum speed with body mass, which holds across locomotion modes, ecosystem types and taxonomic groups. In contrast to traditional power-law scaling, we predict a hump-shaped relationship resulting from a finite acceleration time for animals, which explains why the largest animals are not the fastest. This model is strongly supported by extensive empirical data (474 species, with body masses ranging from 30 μg to 100 tonnes) from terrestrial as well as aquatic ecosystems. Our approach unravels a fundamental constraint on the upper limit of animal movement, thus enabling a better understanding of realized movement patterns in nature and their multifold ecological consequences.

  8. Largest solar installation on a hotel in Switzerland; Groesste Hotel-Solaranlage der Schweiz

    Energy Technology Data Exchange (ETDEWEB)

    Stadelmann, M.

    2008-07-01

    This article describes the solar thermal installation on the Hotel Europa in St. Moritz-Champfer, Switzerland. The installation provides heat energy for domestic hot water preparation and for the heating of the hotel's indoor swimming pool. A thirty-percent reduction of heating oil consumption has been obtained. The system, which is based on the 'low-flow' principle, provides the highest possible temperature difference while using low pumping energy. The hotel's hot-water circulation system, which ensures fast availability of hot water at the taps, is also discussed. This largest hotel solar installation is designed to meet heating and hot-water requirements during the summer season. The high requirements placed on the materials used are discussed. Schematics are provided and first operational experience is briefly discussed.

  9. Using Largest Lyapunov Exponent to Confirm the Intrinsic Stability of Boiling Water Reactors

    Directory of Open Access Journals (Sweden)

    Carlos J. Gavilán-Moreno

    2016-04-01

    Full Text Available The aim of this paper is the study of instability state of boiling water reactors with a method based in largest Lyapunov exponents (LLEs. Detecting the presence of chaos in a dynamical system is an important problem that is solved by measuring the LLE. Lyapunov exponents quantify the exponential divergence of initially close state-space trajectories and estimate the amount of chaos in a system. This method was applied to a set of signals from several nuclear power plant (NPP reactors under commercial operating conditions that experienced instabilities events, apparently each of a different nature. Laguna Verde and Forsmark NPPs with in-phase instabilities, and Cofrentes NPP with out-of-phases instability. This study presents the results of intrinsic instability in the boiling water reactors of three NPPs. In the analyzed cases the limit cycle was not reached, which implies that the point of equilibrium exerts influence and attraction on system evolution.

  10. From Pushing Paper to Pushing Dirt - Canada's Largest LLRW Cleanup Gets Underway - 13111

    International Nuclear Information System (INIS)

    Veen, Walter van; Lawrence, Dave

    2013-01-01

    The Port Hope Project is the larger of the two projects in the Port Hope Area Initiative (PHAI), Canada's largest low level radioactive waste (LLRW) cleanup. With a budget of approximately $1 billion, the Port Hope Project includes a broad and complex range of remedial elements from a state of the art water treatment plant, an engineered waste management facility, municipal solid waste removal, remediation of 18 major sites within the Municipality of Port Hope (MPH), sediment dredging and dewatering, an investigation of 4,800 properties (many of these homes) to identify LLRW and remediation of approximately 450 of these properties. This paper discusses the status of the Port Hope Project in terms of designs completed and regulatory approvals received, and sets out the scope and schedule for the remaining studies, engineering designs and remediation contracts. (authors)

  11. A marine heatwave drives massive losses from the world's largest seagrass carbon stocks

    Science.gov (United States)

    Arias-Ortiz, A.; Serrano, O.; Masqué, P.; Lavery, P. S.; Mueller, U.; Kendrick, G. A.; Rozaimi, M.; Esteban, A.; Fourqurean, J. W.; Marbà, N.; Mateo, M. A.; Murray, K.; Rule, M. J.; Duarte, C. M.

    2018-04-01

    Seagrass ecosystems contain globally significant organic carbon (C) stocks. However, climate change and increasing frequency of extreme events threaten their preservation. Shark Bay, Western Australia, has the largest C stock reported for a seagrass ecosystem, containing up to 1.3% of the total C stored within the top metre of seagrass sediments worldwide. On the basis of field studies and satellite imagery, we estimate that 36% of Shark Bay's seagrass meadows were damaged following a marine heatwave in 2010/2011. Assuming that 10 to 50% of the seagrass sediment C stock was exposed to oxic conditions after disturbance, between 2 and 9 Tg CO2 could have been released to the atmosphere during the following three years, increasing emissions from land-use change in Australia by 4-21% per annum. With heatwaves predicted to increase with further climate warming, conservation of seagrass ecosystems is essential to avoid adverse feedbacks on the climate system.

  12. Mapping Biomass for REDD in the Largest Forest of Central Africa: the Democratic Republic of Congo

    Science.gov (United States)

    Shapiro, Aurelie; Saatchi, Sassan

    2014-05-01

    With the support of the International Climate Initiative (ICI) of the Federal Ministry of the Environment, Conservation, and Nuclear Security, the implementation of the German Development Bank KfW, the World Wide Fund for Nature (WWF) Germany, the University of California Los Angeles (UCLA) and local DRC partners will produce a national scale biomass map for the entire forest coverage of the Democratic Republic of Congo (DRC) along with feasibility assessments of different forest protection measures within a framework of a REDD+ model project. The « Carbon Map and Model (CO2M&M) » project will produce a national forest biomass map for the DRC, which will enable quantitative assessments of carbon stocks and emissions in the largest forest of the Congo Basin. This effort will support the national REDD (Reducing Emissions from Deforestation and Degradation) program in DRC, which plays a major role in sustainable development and poverty alleviation. This map will be developed from field data, complemented by airborne LiDAR (Light Detection and Ranging) and aerial photos, systematically sampled throughout the forests of the DRC and up-scaled to satellite images to accurately estimate carbon content in all forested areas. The second component of the project is to develop specific approaches for model REDD projects in key landscapes. This project represents the largest LiDAR-derived mapping effort in Africa, under unprecedented logistical constraints, which will provide one of the poorest nations in the world with the richest airborne and satellites derived datasets for analyzing forest structure, biomass and biodiversity.

  13. Dissolved Oxygen Dynamics in Backwaters of North America's Largest River Swamp

    Science.gov (United States)

    Bueche, S. M.; Xu, Y. J.; Reiman, J. H.

    2017-12-01

    The Atchafalaya River (AR) is the largest distributary of the Mississippi River flowing through south-central Louisiana, creating North America's largest river swamp basin - the Atchafalaya River Basin (ARB). Prior to human settlement, the AR's main channel was highly connected to this large wetland ecosystem. However, due to constructed levee systems and other human modifications, much of the ARB is now hydrologically disconnected from the AR's main channel except during high flow events. This lack of regular inputs of fresh, oxygenated water to these wetlands, paired with high levels of organic matter decomposition in wetlands, has caused low oxygen-deprived hypoxic conditions in the ARB's back waters. In addition, due to the incredibly nutrient-rich and warm nature of the ARB, microbial decomposition in backwater areas with limited flow often results in potentially stressful, if not lethal, levels of DO for organisms during and after flood pulses. This study aims to investigate dynamics of dissolved oxygen in backwaters of the Atchafalaya River Basin, intending to answer a crucial question about hydrological and water quality connectivity between the river's mainstem and its floodplain. Specifically, the study will 1) conduct field water quality measurements, 2) collect composite water samples for chemical analysis of nutrients and carbon, 3) investigate DO dynamics over different seasons for one year, and 4) determine the major factors that affect DO dynamics in this unique swamp ecosystem. The study is currently underway; therefore, in this presentation we will share the major findings gained in the past several months and discuss backwater effects on river chemistry.

  14. Is Kasei Valles (Mars) the largest volcanic channel in the solar system?

    Science.gov (United States)

    Leverington, David W.

    2018-02-01

    With a length of more than 2000 km and widths of up to several hundred kilometers, Kasei Valles is the largest outflow system on Mars. Superficially, the scabland-like character of Kasei Valles is evocative of terrestrial systems carved by catastrophic aqueous floods, and the system is widely interpreted as a product of outbursts from aquifers. However, as at other Martian outflow channels, clear examples of fluvial sedimentary deposits have proven difficult to identify here. Though Kasei Valles lacks several key properties expected of aqueous systems, its basic morphological and contextual properties are aligned with those of ancient volcanic channels on Venus, the Moon, Mercury, and Earth. There is abundant evidence that voluminous effusions of low-viscosity magmas occurred at the head of Kasei Valles, the channel system acted as a conduit for associated flows, and mare-style volcanic plains developed within its terminal basin. Combined mechanical and thermal incision rates of at least several meters per day are estimated to have been readily achieved at Kasei Valles by 20-m-deep magmas flowing with viscosities of 1 Pa s across low topographic slopes underlain by bedrock. If Kasei Valles formed through incision by magma, it would be the largest known volcanic channel in the solar system. The total volume of magma erupted at Kasei Valles is estimated here to have possibly reached or exceeded ∼5 × 106 km3, a volume comparable in magnitude to those that characterize individual Large Igneous Provinces on Earth. Development of other large outflow systems on Mars is expected to have similarly involved eruption of up to millions of cubic kilometers of magma.

  15. DGAT enzymes and triacylglycerol biosynthesis

    OpenAIRE

    Yen, Chi-Liang Eric; Stone, Scot J.; Koliwad, Suneil; Harris, Charles; Farese, Robert V.

    2008-01-01

    Triacylglycerols (triglycerides) (TGs) are the major storage molecules of metabolic energy and FAs in most living organisms. Excessive accumulation of TGs, however, is associated with human diseases, such as obesity, diabetes mellitus, and steatohepatitis. The final and the only committed step in the biosynthesis of TGs is catalyzed by acyl-CoA:diacylglycerol acyltransferase (DGAT) enzymes. The genes encoding two DGAT enzymes, DGAT1 and DGAT2, were identified in the past decade, ...

  16. Enzymes: principles and biotechnological applications

    Science.gov (United States)

    Robinson, Peter K.

    2015-01-01

    Enzymes are biological catalysts (also known as biocatalysts) that speed up biochemical reactions in living organisms, and which can be extracted from cells and then used to catalyse a wide range of commercially important processes. This chapter covers the basic principles of enzymology, such as classification, structure, kinetics and inhibition, and also provides an overview of industrial applications. In addition, techniques for the purification of enzymes are discussed. PMID:26504249

  17. de novo computational enzyme design.

    Science.gov (United States)

    Zanghellini, Alexandre

    2014-10-01

    Recent advances in systems and synthetic biology as well as metabolic engineering are poised to transform industrial biotechnology by allowing us to design cell factories for the sustainable production of valuable fuels and chemicals. To deliver on their promises, such cell factories, as much as their brick-and-mortar counterparts, will require appropriate catalysts, especially for classes of reactions that are not known to be catalyzed by enzymes in natural organisms. A recently developed methodology, de novo computational enzyme design can be used to create enzymes catalyzing novel reactions. Here we review the different classes of chemical reactions for which active protein catalysts have been designed as well as the results of detailed biochemical and structural characterization studies. We also discuss how combining de novo computational enzyme design with more traditional protein engineering techniques can alleviate the shortcomings of state-of-the-art computational design techniques and create novel enzymes with catalytic proficiencies on par with natural enzymes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Engineering Cellulase Enzymes for Bioenergy

    Science.gov (United States)

    Atreya, Meera Elizabeth

    Sustainable energy sources, such as biofuels, offer increasingly important alternatives to fossil fuels that contribute less to global climate change. The energy contained within cellulosic biofuels derives from sunlight energy stored in the form of carbon-carbon bonds comprising sugars such as glucose. Second-generation biofuels are produced from lignocellulosic biomass feedstocks, including agricultural waste products and non-food crops like Miscanthus, that contain lignin and the polysaccharides hemicellulose and cellulose. Cellulose is the most abundant biological material on Earth; it is a polymer of glucose and a structural component of plant cell walls. Accessing the sugar is challenging, as the crystalline structure of cellulose resists degradation; biochemical and thermochemical means can be used to depolymerize cellulose. Cellulase enzymes catalyze the biochemical depolymerization of cellulose into glucose. Glucose can be used as a carbon source for growth of a biofuel-producing microorganism. When it converts glucose to a hydrocarbon fuel, this microbe completes the biofuels process of transforming sunlight energy into accessible, chemical energy capable of replacing non-renewable transportation fuels. Due to strong intermolecular interactions between polymer chains, cellulose is significantly more challenging to depolymerize than starch, a more accessible polymer of glucose utilized in first-generation biofuels processes (often derived from corn). While most mammals cannot digest cellulose (dietary fiber), certain fungi and bacteria produce cellulase enzymes capable of hydrolyzing it. These organisms secrete a wide variety of glycoside hydrolase and other classes of enzymes that work in concert. Because cellulase enzymes are slow-acting and expensive to produce, my aim has been to improve the properties of these enzymes as a means to make a cellulosic biofuels process possible that is more efficient and, consequently, more economical than current

  19. Phosphoenolpyruvate-dependent protein kinase enzyme I of Streptococcus faecalis: purification and properties of the enzyme and characterization of its active center

    International Nuclear Information System (INIS)

    Alpert, C.A.; Frank, R.; Stueber, K.D.; Deutscher, J.; Hengstenberg, W.

    1985-01-01

    Enzyme I, the phosphoenolpyruvate:protein phosphotransferase (EC 2.7.3.9), which is part of the bacterial phosphoenolpyruvate-(PEP) dependent phosphotransferase system, has been purified from Streptococcus faecalis by using a large-scale preparation. Size exclusion chromatography revealed a molecular weight of 140,000. On sodium dodecyl sulfate gels, enzyme I gave one band with a molecular weight of 70,000, indicating that enzyme I consists of two identical subunits. The first 59 amino acids of the amino-terminal part of the protein have been sequenced. It showed some similarities with enzyme I of Salmonella typhimurium. The active center of enzyme I has also been determined. After phosphorylation with [ 32 P]PEP, the enzyme was cleaved by using different proteases. Labeled peptides were isolated by high-performance liquid chromatography on a reversed-phase column. The amino acid composition or amino acid sequence of the peptides has been determined. The largest labeled peptide was obtained with Lys-C protease and had the following sequence: -Ala-Phe-Val-Thr-Asp-Ile-Gly- Gly-Arg-Thr-Ser-His*-Ser-Ala-Ile-Met-Ala-Arg-Ser-Leu-Glu-Ile-Pro-Ala- Ile-Val-Gly-Thr-Lys-. It has previously been shown that the phosphoryl group is bound to the N-3 position of a histidyl residue in phosphorylated enzyme I. The single His in position 12 of the above peptide must therefore carry the phosphoryl group

  20. Enzymes and Enzyme Activity Encoded by Nonenveloped Viruses.

    Science.gov (United States)

    Azad, Kimi; Banerjee, Manidipa; Johnson, John E

    2017-09-29

    Viruses are obligate intracellular parasites that rely on host cell machineries for their replication and survival. Although viruses tend to make optimal use of the host cell protein repertoire, they need to encode essential enzymatic or effector functions that may not be available or accessible in the host cellular milieu. The enzymes encoded by nonenveloped viruses-a group of viruses that lack any lipid coating or envelope-play vital roles in all the stages of the viral life cycle. This review summarizes the structural, biochemical, and mechanistic information available for several classes of enzymes and autocatalytic activity encoded by nonenveloped viruses. Advances in research and development of antiviral inhibitors targeting specific viral enzymes are also highlighted.

  1. Rethinking fundamentals of enzyme action.

    Science.gov (United States)

    Northrop, D B

    1999-01-01

    Despite certain limitations, investigators continue to gainfully employ concepts rooted in steady-state kinetics in efforts to draw mechanistically relevant inferences about enzyme catalysis. By reconsidering steady-state enzyme kinetic behavior, this review develops ideas that allow one to arrive at the following new definitions: (a) V/K, the ratio of the maximal initial velocity divided by the Michaelis-Menten constant, is the apparent rate constant for the capture of substrate into enzyme complexes that are destined to yield product(s) at some later point in time; (b) the maximal velocity V is the apparent rate constant for the release of substrate from captured complexes in the form of free product(s); and (c) the Michaelis-Menten constant K is the ratio of the apparent rate constants for release and capture. The physiologic significance of V/K is also explored to illuminate aspects of antibiotic resistance, the concept of "perfection" in enzyme catalysis, and catalytic proficiency. The conceptual basis of congruent thermodynamic cycles is also considered in an attempt to achieve an unambiguous way for comparing an enzyme-catalyzed reaction with its uncatalyzed reference reaction. Such efforts promise a deeper understanding of the origins of catalytic power, as it relates to stabilization of the reactant ground state, stabilization of the transition state, and reciprocal stabilizations of ground and transition states.

  2. Landscapes of thermal inequity: disproportionate exposure to urban heat in the three largest US cities

    Science.gov (United States)

    Mitchell, Bruce C.; Chakraborty, Jayajit

    2015-11-01

    Heat waves are the most significant cause of mortality in the US compared to other natural hazards. Prior studies have found increased heat exposure for individuals of lower socioeconomic status in several US cities, but few comparative analyses of the social distribution of urban heat have been conducted. To address this gap, our paper examines and compares the environmental justice consequences of urban heat risk in the three largest US cities: New York City, Los Angeles, and Chicago. Risk to urban heat is estimated on the basis of three characteristics of the urban thermal landscape: land surface temperature, vegetation abundance, and structural density of the built urban environment. These variables are combined to develop an urban heat risk index, which is then statistically compared with social vulnerability indicators representing socioeconomic status, age, disability, race/ethnicity, and linguistic isolation. The results indicate a consistent and significant statistical association between lower socioeconomic and minority status and greater urban heat risk, in all three cities. Our findings support a growing body of environmental justice literature that indicates the presence of a landscape of thermal inequity in US cities and underscores the need to conduct comparative analyses of social inequities in exposure to urban heat.

  3. KEPLER-1647B: THE LARGEST AND LONGEST-PERIOD KEPLER TRANSITING CIRCUMBINARY PLANET

    Energy Technology Data Exchange (ETDEWEB)

    Kostov, Veselin B. [NASA Goddard Space Flight Center, Mail Code 665, Greenbelt, MD 20771 (United States); Orosz, Jerome A.; Welsh, William F.; Short, Donald R. [Department of Astronomy, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182 (United States); Doyle, Laurance R. [SETI Institute, 189 Bernardo Avenue, Mountain View, CA 94043 (United States); Principia College, IMoP, One Maybeck Place, Elsah, IL 62028 (United States); Fabrycky, Daniel C. [Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Haghighipour, Nader [Institute for Astronomy, University of Hawaii-Manoa, Honolulu, HI 96822 (United States); Quarles, Billy [Department of Physics and Physical Science, The University of Nebraska at Kearney, Kearney, NE 68849 (United States); Cochran, William D.; Endl, Michael [McDonald Observatory, The University of Texas as Austin, Austin, TX 78712-0259 (United States); Ford, Eric B. [Department of Astronomy and Astrophysics, The Pennsylvania State University, 428A Davey Lab, University Park, PA 16802 (United States); Gregorio, Joao [Atalaia Group and Crow-Observatory, Portalegre (Portugal); Hinse, Tobias C. [Korea Astronomy and Space Science Institute (KASI), Advanced Astronomy and Space Science Division, Daejeon 305-348 (Korea, Republic of); Isaacson, Howard [Department of Astronomy, University of California Berkeley, 501 Campbell Hall, Berkeley, CA 94720 (United States); Jenkins, Jon M. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Jensen, Eric L. N. [Department of Physics and Astronomy, Swarthmore College, Swarthmore, PA 19081 (United States); Kane, Stephen [Department of Physics and Astronomy, San Francisco State University, 1600 Holloway Avenue, San Francisco, CA 94132 (United States); Kull, Ilya, E-mail: veselin.b.kostov@nasa.gov [Department of Astronomy and Astrophysics, Tel Aviv University, 69978 Tel Aviv (Israel); and others

    2016-08-10

    We report the discovery of a new Kepler transiting circumbinary planet (CBP). This latest addition to the still-small family of CBPs defies the current trend of known short-period planets orbiting near the stability limit of binary stars. Unlike the previous discoveries, the planet revolving around the eclipsing binary system Kepler-1647 has a very long orbital period (∼1100 days) and was at conjunction only twice during the Kepler mission lifetime. Due to the singular configuration of the system, Kepler-1647b is not only the longest-period transiting CBP at the time of writing, but also one of the longest-period transiting planets. With a radius of 1.06 ± 0.01 R {sub Jup}, it is also the largest CBP to date. The planet produced three transits in the light curve of Kepler-1647 (one of them during an eclipse, creating a syzygy) and measurably perturbed the times of the stellar eclipses, allowing us to measure its mass, 1.52 ± 0.65 M {sub Jup}. The planet revolves around an 11-day period eclipsing binary consisting of two solar-mass stars on a slightly inclined, mildly eccentric ( e {sub bin} = 0.16), spin-synchronized orbit. Despite having an orbital period three times longer than Earth’s, Kepler-1647b is in the conservative habitable zone of the binary star throughout its orbit.

  4. Evidence for protection of targeted reef fish on the largest marine reserve in the Caribbean.

    Science.gov (United States)

    Pina-Amargós, Fabián; González-Sansón, Gaspar; Martín-Blanco, Félix; Valdivia, Abel

    2014-01-01

    Marine reserves can restore fish abundance and diversity in areas impacted by overfishing, but the effectiveness of reserves in developing countries where resources for enforcement are limited, have seldom been evaluated. Here we assess whether the establishment in 1996 of the largest marine reserve in the Caribbean, Gardens of the Queen in Cuba, has had a positive effect on the abundance of commercially valuable reef fish species in relation to neighboring unprotected areas. We surveyed 25 sites, including two reef habitats (reef crest and reef slope), inside and outside the marine reserve, on five different months, and over a one-and-a-half year period. Densities of the ten most frequent, highly targeted, and relatively large fish species showed a significant variability across the archipelago for both reef habitats that depended on the month of survey. These ten species showed a tendency towards higher abundance inside the reserve in both reef habitats for most months during the study. Average fish densities pooled by protection level, however, showed that five out of these ten species were at least two-fold significantly higher inside than outside the reserve at one or both reef habitats. Supporting evidence from previously published studies in the area indicates that habitat complexity and major benthic communities were similar inside and outside the reserve, while fishing pressure appeared to be homogeneous across the archipelago before reserve establishment. Although poaching may occur within the reserve, especially at the boundaries, effective protection from fishing was the most plausible explanation for the patterns observed.

  5. Scaling relationships among drivers of aquatic respiration from the smallest to the largest freshwater ecosystems

    Science.gov (United States)

    Hall, Ed K; Schoolmaster, Donald; Amado, A.M; Stets, Edward G.; Lennon, J.T.; Domaine, L.; Cotner, J.B.

    2016-01-01

    To address how various environmental parameters control or constrain planktonic respiration (PR), we used geometric scaling relationships and established biological scaling laws to derive quantitative predictions for the relationships among key drivers of PR. We then used empirical measurements of PR and environmental (soluble reactive phosphate [SRP], carbon [DOC], chlorophyll a [Chl-a)], and temperature) and landscape parameters (lake area [LA] and watershed area [WA]) from a set of 44 lakes that varied in size and trophic status to test our hypotheses. We found that landscape-level processes affected PR through direct effects on DOC and temperature and indirectly via SRP. In accordance with predictions made from known relationships and scaling laws, scale coefficients (the parameter that describes the shape of a relationship between 2 variables) were found to be negative and have an absolute value 1, others respiration from small pond catchments to the largest body of freshwater on the planet, Lake Superior, these findings should be applicable to controls of PR for the great majority of temperate aquatic ecosystems.

  6. Investigation of science faculty with education specialties within the largest university system in the United States.

    Science.gov (United States)

    Bush, Seth D; Pelaez, Nancy J; Rudd, James A; Stevens, Michael T; Tanner, Kimberly D; Williams, Kathy S

    2011-01-01

    Efforts to improve science education include university science departments hiring Science Faculty with Education Specialties (SFES), scientists who take on specialized roles in science education within their discipline. Although these positions have existed for decades and may be growing more common, few reports have investigated the SFES approach to improving science education. We present comprehensive data on the SFES in the California State University (CSU) system, the largest university system in the United States. We found that CSU SFES were engaged in three key arenas including K-12 science education, undergraduate science education, and discipline-based science education research. As such, CSU SFES appeared to be well-positioned to have an impact on science education from within science departments. However, there appeared to be a lack of clarity and agreement about the purpose of these SFES positions. In addition, formal training in science education among CSU SFES was limited. Although over 75% of CSU SFES were fulfilled by their teaching, scholarship, and service, our results revealed that almost 40% of CSU SFES were seriously considering leaving their positions. Our data suggest that science departments would likely benefit from explicit discussions about the role of SFES and strategies for supporting their professional activities.

  7. Sources and distribution of microplastics in China's largest inland lake - Qinghai Lake.

    Science.gov (United States)

    Xiong, Xiong; Zhang, Kai; Chen, Xianchuan; Shi, Huahong; Luo, Ze; Wu, Chenxi

    2018-04-01

    Microplastic pollution was studied in China's largest inland lake - Qinghai Lake in this work. Microplastics were detected with abundance varies from 0.05 × 10 5 to 7.58 × 10 5 items km -2 in the lake surface water, 0.03 × 10 5 to 0.31 × 10 5 items km -2 in the inflowing rivers, 50 to 1292 items m -2 in the lakeshore sediment, and 2 to 15 items per individual in the fish samples, respectively. Small microplastics (0.1-0.5 mm) dominated in the lake surface water while large microplastics (1-5 mm) are more abundant in the river samples. Microplastics were predominantly in sheet and fiber shapes in the lake and river water samples but were more diverse in the lakeshore sediment samples. Polymer types of microplastics were mainly polyethylene (PE) and polypropylene (PP) as identified using Raman Spectroscopy. Spatially, microplastic abundance was the highest in the central part of the lake, likely due to the transport of lake current. Based on the higher abundance of microplastics near the tourist access points, plastic wastes from tourism are considered as an important source of microplastics in Qinghai Lake. As an important area for wildlife conservation, better waste management practice should be implemented, and waste disposal and recycling infrastructures should be improved for the protection of Qinghai Lake. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. The largest human cognitive performance dataset reveals insights into the effects of lifestyle factors and aging

    Directory of Open Access Journals (Sweden)

    Daniel A Sternberg

    2013-06-01

    Full Text Available Making new breakthroughs in understanding the processes underlying human cognition may depend on the availability of very large datasets that have not historically existed in psychology and neuroscience. Lumosity is a web-based cognitive training platform that has grown to include over 600 million cognitive training task results from over 35 million individuals, comprising the largest existing dataset of human cognitive performance. As part of the Human Cognition Project, Lumosity’s collaborative research program to understand the human mind, Lumos Labs researchers and external research collaborators have begun to explore this dataset in order uncover novel insights about the correlates of cognitive performance. This paper presents two preliminary demonstrations of some of the kinds of questions that can be examined with the dataset. The first example focuses on replicating known findings relating lifestyle factors to baseline cognitive performance in a demographically diverse, healthy population at a much larger scale than has previously been available. The second example examines a question that would likely be very difficult to study in laboratory-based and existing online experimental research approaches: specifically, how learning ability for different types of cognitive tasks changes with age. We hope that these examples will provoke the imagination of researchers who are interested in collaborating to answer fundamental questions about human cognitive performance.

  9. Reconstructing the population history of the largest tribe of India: the Dravidian speaking Gond.

    Science.gov (United States)

    Chaubey, Gyaneshwer; Tamang, Rakesh; Pennarun, Erwan; Dubey, Pavan; Rai, Niraj; Upadhyay, Rakesh Kumar; Meena, Rajendra Prasad; Patel, Jayanti R; van Driem, George; Thangaraj, Kumarasamy; Metspalu, Mait; Villems, Richard

    2017-04-01

    The Gond comprise the largest tribal group of India with a population exceeding 12 million. Linguistically, the Gond belong to the Gondi-Manda subgroup of the South Central branch of the Dravidian language family. Ethnographers, anthropologists and linguists entertain mutually incompatible hypotheses on their origin. Genetic studies of these people have thus far suffered from the low resolution of the genetic data or the limited number of samples. Therefore, to gain a more comprehensive view on ancient ancestry and genetic affinities of the Gond with the neighbouring populations speaking Indo-European, Dravidian and Austroasiatic languages, we have studied four geographically distinct groups of Gond using high-resolution data. All the Gond groups share a common ancestry with a certain degree of isolation and differentiation. Our allele frequency and haplotype-based analyses reveal that the Gond share substantial genetic ancestry with the Indian Austroasiatic (ie, Munda) groups, rather than with the other Dravidian groups to whom they are most closely related linguistically.

  10. A study on the regionalization of tornadogenesis for the domestic largest scale of tornado

    International Nuclear Information System (INIS)

    Sugimoto, Soichiro; Nohara, Daisuke; Hirakuchi, Hiromaru

    2014-01-01

    A new regulatory guide has been issued by the Nuclear Regulation Authority of Japan since the last year. According to this guide, electric power companies have to assess the influence of tornadoes on their nuclear power plants for operation. The purpose of this study is to evaluate the likelihood of the occurrence of F3 tornadoes, which are the largest encountered in Japan, and to consider the possibility of the regionalization of the maximum wind speed. Then, mesoscale analysis with a numerical meteorological model and re-analysis data is performed along with synoptic scale analysis. Especially, tornado parameters such as SReH (Storm Relative Helicity) and CAPE (Convective Available Potential Energy) are used for evaluating the potential tornadogenesis of F3 tornado. Both analyses indicate that favorable meteorological condition tends to occur in the coastal zones in the Pacific side west of Ibaraki and around Kyushu island. The frequency in these zones is different from the one in the other area in the order of 1 or 2, which is large enough for regionalization. (author)

  11. Vascular access in lipoprotein apheresis: a retrospective analysis from the UK's largest lipoprotein apheresis centre.

    Science.gov (United States)

    Doherty, Daniel J; Pottle, Alison; Malietzis, George; Hakim, Nadey; Barbir, Mahmoud; Crane, Jeremy S

    2018-01-01

    Lipoprotein apheresis (LA) has proven to be an effective, safe and life-saving therapy. Vascular access is needed to facilitate this treatment but has recognised complications. Despite consistency in treatment indication and duration there are no guidelines in place. The aim of this study is to characterise vascular access practice at the UK's largest LA centre and forward suggestions for future approaches. A retrospective analysis of vascular access strategies was undertaken in all patients who received LA treatment in the low-density lipoprotein (LDL) Apheresis Unit at Harefield Hospital (Middlesex, UK) from November 2000 to March 2016. Fifty-three former and current patients underwent 4260 LA treatments. Peripheral vein cannulation represented 79% of initial vascular access strategies with arteriovenous (AV) fistula use accounting for 15%. Last used method of vascular access was peripheral vein cannulation in 57% versus AV fistula in 32%. Total AV fistula failure rate was 37%. Peripheral vein cannulation remains the most common method to facilitate LA. Practice trends indicate a move towards AV fistula creation; the favoured approach receiving support from the expert body in this area. AV fistula failure rate is high and of great concern, therefore we suggest the implementation of upper limb ultrasound vascular mapping in all patients who meet treatment eligibility criteria. We encourage close ties between apheresis units and specialist surgical centres to facilitate patient counselling and monitoring. Further prospective data regarding fistula failure is needed in this expanding treatment field.

  12. Sistema Faro, Isla de Mona, Puerto Rico: speleogenesis of the worlds largest flank margin cave

    International Nuclear Information System (INIS)

    Lace, M. J.; Kambesis, P. N.; Mylroie, J. E.

    2016-01-01

    Isla de Mona, a small, uplifted carbonate plateau jutting out of the waters of the Mona Passage, is an incredibly fragile and densely karstic environment. Expedition work was conducted by the Isla de Mona Project in cooperation with the Departamento Recursos Naturales y Ambientales de Puerto Rico (DRNA), including contributions from many researchers and cavers volunteering from across the U.S and Puerto Rico in the course of 12 separate expeditions, spanning a 14 year period (1998 to 2013). Over 200 caves have been documented on the island to date, the majority of this inventory is composed of flank margin caves but also includes sea caves, pit caves and talus caves. The most extensive example of cave development on the island is Sistema Faro - a sprawling maze-like series of chambers formed within the eastern point of the island with over 40 cliffside entrances overlooking the Caribbean Sea. Detailed cartography and analysis of the geomorphology and development of the Sistema Faro has helped form a complex model of carbonate island cave development as a function of tectonic uplift, lithology, sea level changes, karst hydrogeology and cliff retreat. This communication examines the roles these controls have played in the genesis of the world's largest flank margin cave. (Author)

  13. Stand Up for the Burrup: Saving the Largest Aboriginal Rock Art Precinct in Australia

    Directory of Open Access Journals (Sweden)

    Jenny Gregory

    2009-12-01

    Full Text Available The Dampier Rock Art Precinct contains the largest and most ancient collection of Aboriginal rock art in Australia. The cultural landscape created by generations of Aboriginal people includes images of long-extinct fauna and demonstrates the response of peoples to a changing climate over thousands of years as well as the continuity of lived experience. Despite Australian national heritage listing in 2007, this cultural landscape continues to be threatened by industrial development. Rock art on the eastern side of the archipelago, on the Burrup Peninsula, was relocated following the discovery of adjacent off-shore gas reserves so that a major gas plant could be constructed. Work has now begun on the construction of a second major gas plant nearby. This article describes the rock art of the Dampier Archipelago and the troubled history of European-Aboriginal contact history, before examining the impact of industry on the region and its environment. The destruction of Aboriginal rock art to meet the needs of industry is an example of continuing indifference to Aboriginal culture. While the complex struggle to protect the cultural landscape of the Burrup, in particular, involving Indigenous people, archaeologists, historians, state and federal politicians, government bureaucrats and multi-national companies, eventually led to national heritage listing, it is not clear that the battle to save the Burrup has been won.

  14. Percolation under noise: Detecting explosive percolation using the second-largest component

    Science.gov (United States)

    Viles, Wes; Ginestet, Cedric E.; Tang, Ariana; Kramer, Mark A.; Kolaczyk, Eric D.

    2016-05-01

    We consider the problem of distinguishing between different rates of percolation under noise. A statistical model of percolation is constructed allowing for the birth and death of edges as well as the presence of noise in the observations. This graph-valued stochastic process is composed of a latent and an observed nonstationary process, where the observed graph process is corrupted by type-I and type-II errors. This produces a hidden Markov graph model. We show that for certain choices of parameters controlling the noise, the classical (Erdős-Rényi) percolation is visually indistinguishable from a more rapid form of percolation. In this setting, we compare two different criteria for discriminating between these two percolation models, based on the interquartile range (IQR) of the first component's size, and on the maximal size of the second-largest component. We show through data simulations that this second criterion outperforms the IQR of the first component's size, in terms of discriminatory power. The maximal size of the second component therefore provides a useful statistic for distinguishing between different rates of percolation, under physically motivated conditions for the birth and death of edges, and under noise. The potential application of the proposed criteria for the detection of clinically relevant percolation in the context of applied neuroscience is also discussed.

  15. North Andean origin and diversification of the largest ithomiine butterfly genus

    Science.gov (United States)

    Lisa De-Silva, Donna; Mota, Luísa L.; Chazot, Nicolas; Mallarino, Ricardo; Silva-Brandão, Karina L.; Piñerez, Luz Miryam Gómez; Freitas, André V.L.; Lamas, Gerardo; Joron, Mathieu; Mallet, James; Giraldo, Carlos E.; Uribe, Sandra; Särkinen, Tiina; Knapp, Sandra; Jiggins, Chris D.; Willmott, Keith R.; Elias, Marianne

    2017-01-01

    The Neotropics harbour the most diverse flora and fauna on Earth. The Andes are a major centre of diversification and source of diversity for adjacent areas in plants and vertebrates, but studies on insects remain scarce, even though they constitute the largest fraction of terrestrial biodiversity. Here, we combine molecular and morphological characters to generate a dated phylogeny of the butterfly genus Pteronymia (Nymphalidae: Danainae), which we use to infer spatial, elevational and temporal diversification patterns. We first propose six taxonomic changes that raise the generic species total to 53, making Pteronymia the most diverse genus of the tribe Ithomiini. Our biogeographic reconstruction shows that Pteronymia originated in the Northern Andes, where it diversified extensively. Some lineages colonized lowlands and adjacent montane areas, but diversification in those areas remained scarce. The recent colonization of lowland areas was reflected by an increase in the rate of evolution of species’ elevational ranges towards present. By contrast, speciation rate decelerated with time, with no extinction. The geological history of the Andes and adjacent regions have likely contributed to Pteronymia diversification by providing compartmentalized habitats and an array of biotic and abiotic conditions, and by limiting dispersal between some areas while promoting interchange across others. PMID:28387233

  16. Level of patient and operator dose in the largest cardiac centre in Greece

    International Nuclear Information System (INIS)

    Tsapaki, V.; Patsilinakos, S.; Voudris, V.; Magginas, A.; Pavlidis, S.; Maounis, T.; Theodorakis, G.; Koutelou, M.; Vrantza, T.; Nearchou, M.; Nikolaki, N.; Kollaros, N.; Kyrozi, E.; Kottou, S.; Karaiskos, P.; Neofotistou, E.; Cokkinos, D.

    2008-01-01

    The objective of this study was to investigate the patient and staff doses in the most frequent interventional cardiology (IC) procedures performed in Onassio, the largest Cardiac Centre in Greece. Data were collected from three digital X-ray systems for 212 coronary angiographies, 203 percutaneous transluminal coronary angio-plasties (PTCA) and 134 various electrophysiological studies. Patient skin dose was measured using suitably calibrated slow radiotherapy films and cardiologist dose using suitably calibrated thermoluminescent dosemeters placed on left arm, hand and foot. Patient median dose area product (DAP) (all examinations) ranged between 6.7 and 83.5 Gy cm 2 . Patient median skin dose in PTCA was 799 mGy (320-1660 mGy) and in RF ablation 160 mGy (35-1920 mGy). Median arm, hand and foot dose to the cardiologist were 12.6, 27 and 13 μSv, respectively, per procedure. The great range of radiation doses received by both patients and operators confirms the need for continuous monitoring of all IC techniques. (authors)

  17. DISCOVERY OF THE LARGEST KNOWN LENSED IMAGES FORMED BY A CRITICALLY CONVERGENT LENSING CLUSTER

    International Nuclear Information System (INIS)

    Zitrin, Adi; Broadhurst, Tom

    2009-01-01

    We identify the largest known lensed images of a single spiral galaxy, lying close to the center of the distant cluster MACS J1149.5+2223 (z = 0.544). These images cover a total area of ≅150 mbox '' and are magnified ≅200 times. Unusually, there is very little image distortion, implying that the central mass distribution is almost uniform over a wide area (r ≅ 200 kpc) with a surface density equal to the critical density for lensing, corresponding to maximal lens magnification. Many fainter multiply lensed galaxies are also uncovered by our model, outlining a very large tangential critical curve, of radius r ≅ 170 kpc, posing a potential challenge for the standard LCDM cosmology. Because of the uniform central mass distribution, a particularly clean measurement of the mass of the brightest cluster galaxy is possible here, for which we infer stars contribute most of the mass within a limiting radius of ≅30 kpc, with a mass-to-light ratio of M/L B ≅ 4.5(M/L) sun . This cluster with its uniform and central mass distribution acts analogously to a regular magnifying glass, converging light without distorting the images, resulting in the most powerful lens yet discovered for accessing the faint high-z universe.

  18. Epidemiological study of hepatitis A, B and C in the largest Afro-Brazilian isolated community.

    Science.gov (United States)

    Matos, Márcia A D; Reis, Nádia Rúbia S; Kozlowski, Aline G; Teles, Sheila A; Motta-Castro, Ana Rita C; Mello, Francisco C A; Gomes, Selma A; Martins, Regina M B

    2009-09-01

    This study was conducted to estimate the prevalence and molecular epidemiological features of viral hepatitis A, B and C in the Kalunga population, which represents the largest Afro-Brazilian isolated community. Among 878 individuals studied, the overall prevalence of anti-hepatitis A virus antibodies was 80.9%, with a significant rise from 44.8% to near 100% between the first and fourth decade of life. Rates for hepatitis B surface antigen (HBsAg) and antibody to hepatitis B core antigen (anti-HBc) of 1.8% and 35.4%, respectively, were found. Increasing age, male gender, illiteracy and history of multiple sexual partners were associated with hepatitis B virus (HBV) infection. An occult HBV infection rate of 1.7% (5/295) was found among anti-HBc-positive individuals. HBV genotype A (subtype Aa) was dominant in this community. Only 5/878 individuals (0.6%) were positive for anti-hepatitis C virus (HCV). HCV RNA was detected in three of them, who were infected with genotype 1 (subtype 1a). These findings point out high, intermediate and low endemicity for hepatitis A, B and C, respectively, in the Kalunga community in Brazil. Circulation of HBV genotype A (subtype Aa) in this Afro-Brazilian isolated community indicates the introduction of this virus during the slave trade from Africa to Brazil.

  19. Bubble nucleation in simple and molecular liquids via the largest spherical cavity method

    International Nuclear Information System (INIS)

    Gonzalez, Miguel A.; Abascal, José L. F.; Valeriani, Chantal; Bresme, Fernando

    2015-01-01

    In this work, we propose a methodology to compute bubble nucleation free energy barriers using trajectories generated via molecular dynamics simulations. We follow the bubble nucleation process by means of a local order parameter, defined by the volume of the largest spherical cavity (LSC) formed in the nucleating trajectories. This order parameter simplifies considerably the monitoring of the nucleation events, as compared with the previous approaches which require ad hoc criteria to classify the atoms and molecules as liquid or vapor. The combination of the LSC and the mean first passage time technique can then be used to obtain the free energy curves. Upon computation of the cavity distribution function the nucleation rate and free-energy barrier can then be computed. We test our method against recent computations of bubble nucleation in simple liquids and water at negative pressures. We obtain free-energy barriers in good agreement with the previous works. The LSC method provides a versatile and computationally efficient route to estimate the volume of critical bubbles the nucleation rate and to compute bubble nucleation free-energies in both simple and molecular liquids

  20. Rise and Fall of one of World's largest deltas; the Mekong delta in Vietnam

    Science.gov (United States)

    Minderhoud, P. S. J.; Eslami Arab, S.; Pham, H. V.; Erkens, G.; van der Vegt, M.; Oude Essink, G.; Stouthamer, E.; Hoekstra, P.

    2017-12-01

    The Mekong delta is the third's largest delta in the world. It is home to almost 20 million people and an important region for the food security in South East Asia. As most deltas, the Mekong delta is the dynamic result of a balance of sediment supply, sea level rise and subsidence, hosting a system of fresh and salt water dynamics. Ongoing urbanization, industrialization and intensification of agricultural practices in the delta, during the past decades, resulted in growing domestic, agricultural and industrial demands, and have led to a dramatic increase of fresh water use. Since the year 2000, the amount of fresh groundwater extracted from the subsurface increased by 500%. This accelerated delta subsidence as the groundwater system compacts, with current sinking rates exceeding global sea level rise up to an order of magnitude. These high sinking rates have greatly altered the sediment budget of the delta and, with over 50% of the Mekong delta surface elevated less than 1 meter above sea level, greatly increase vulnerability to flooding and storm surges and ultimately, permanent inundation. Furthermore, as the increasingly larger extractions rapidly reduce the fresh groundwater reserves, groundwater salinization subsequently increases. On top of that, dry season low-flows by the Mekong river cause record salt water intrusion in the delta's estuarine system, creating major problems for rice irrigation. We present the work of three years research by the Dutch-Vietnamese `Rise and Fall' project on land subsidence and salinization in both groundwater and surface water in the Vietnamese Mekong delta.

  1. Mortgage loans: an analysis of the portfolios of the largest banks in Brazil

    Directory of Open Access Journals (Sweden)

    Bruno Vinícius Ramos Fernandes

    2013-05-01

    Full Text Available Given the current macroeconomic environment experienced in Brazil, where inflation has stabilized and the basic interest rate of the economy is in one of their historical lows, demand for mortgages is increasing. In this context, the mortgage is presented with great emphasis to meet the demand for purchasing housing in addition to being a catalyst for the reduction of the high housing deficit. From a descriptive and empirical-analytic was analyzed the mortgage loan portfolio of the largest banks of the country between the years 2001 and 2010 through Quarterly Financial Information (IFT available on the Central Bank website. It was settled a comparative relationship between the data in order to check the development of mortgage portfolios over the years and the factors that influenced this evolution, and evaluate the timeliness and quality of those loans. For the evolution of the portfolio there was an economic context in which Brazil was included in the period, and observed that for most of these operations are long term the banks are more exposed to market risk. With regard to credit risk parse that, over the years, Brazilian banks are presenting a mortgage loan portfolio with lower risk, and it is found that institutions with real estate credits with higher levels of portfolio risk are subject to have higher losses on such operations in the possibility of default.

  2. Corporate social responsibility of the 100 largest Indian companies – an analysis of website communication

    Directory of Open Access Journals (Sweden)

    Avinash Mulky

    2013-01-01

    Full Text Available Corporate social responsibility has become an important concept in the business world in recent decades. CSR is important in all countries but is particularly relevant in emerging markets where the levels of human development are not high. The United Nations Development Programme has created the Human Development Index (HDI to measure the human development in countries. The present study analyzes the CSR communication on the websites of the 100 largest Indian companies. The objective was to examine the reported CSR activities and determine whether the activities address the dimensions and indicators of the HDI. The study uses content analysis to classify the CSR activities into categories corresponding to HDI parameters. The findings indicate that about two thirds of the companies are using their websites to communicate CSR. Of the companies which reported CSR, about eighty percent report support for primary education and about seventy percent undertake livelihood support activities. The level of corporate involvement in the health dimension of human development is quite low. Reduction of infant and maternal mortality does not get much corporate attention. This study will add to the literature on CSR in emerging markets and will be useful for firms in India and other emerging markets that are planning CSR activities aimed at human development parameters.

  3. Natural radionuclides in soil profiles surrounding the largest coal-fired power plant in Serbia

    Directory of Open Access Journals (Sweden)

    Tanić Milan N.

    2016-01-01

    Full Text Available This study evaluates the influence of the largest Serbian coal-fired power plant on radionuclide concentrations in soil profiles up to 50 cm in depth. Thirty soil profiles were sampled from the plant surroundings (up to 10 km distance and analyzed using standard methods for soil physicochemical properties and gamma ray spectrometry for specific activities of natural radionuclides (40K, 226Ra and 232Th. Spatial and vertical distribution of radionuclides was determined and analyzed to show the relations between the specific activities in the soil and soil properties and the most influential factors of natural radionuclide variability were identified. The radiological indices for surface soil were calculated and radiological risk assessment was performed. The measured specific activities were similar to values of background levels for Serbia. The sampling depth did not show any significant influence on specific activities of natural radionuclides. The strongest predictor of specific activities of the investigated radionuclides was soil granulometry. All parameters of radiological risk assessment were below the recommended values and adopted limits. It appears that the coal-fired power plant does not have a significant impact on the spatial and vertical distribution of natural radionuclides in the area of interest, but technologically enhanced natural radioactivity as a consequence of the plant operations was identified within the first 1.5 km from the power plant. [Projekat Ministarstva nauke Republike Srbije br. III43009 i br. III41005

  4. Largest known Mesozoic multituberculate from Eurasia and implications for multituberculate evolution and biology.

    Science.gov (United States)

    Xu, Li; Zhang, Xingliao; Pu, Hanyong; Jia, Songhai; Zhang, Jiming; Lü, Junchang; Meng, Jin

    2015-10-22

    A new multituberculate, Yubaartar zhongyuanensis gen. and sp. nov., is reported from the Upper Cretaceous of Luanchuan County, Henan Province, China. The holotype of the new taxon is a partial skeleton with nearly complete cranium and associated lower jaws with in situ dentitions. The new species is the southern-most record of a Late Cretaceous multituberculate from outside of the Mongolian Plateau in Asia and represents the largest known Mesozoic multituberculate from Eurasia. The new specimen displays some intriguing features previously unknown in multituberculates, such as the first evidence of replacement of the ultimate upper premolar and a unique paleopathological case in Mesozoic mammals in which the animal with a severely broken right tibia could heal and survive in natural condition. The phylogenetic analysis based on craniodental characters places Yubaartar as the immediate outgroup of Taeniolabidoidea, a group consisting of a North American clade and an Asian clade. This relationship indicates at least a faunal interchange of multituberculates before the K-Pg transition. The new evidence further supports the hypothesis that disparity in dental complexity, which relates to animal diets, increased with generic richness and disparity in body size, and that an adaptive shift towards increased herbivory across the K-Pg transitional interval.

  5. Complex biogeographic scenarios revealed in the diversification of the largest woodpecker radiation in the New World.

    Science.gov (United States)

    Navarro-Sigüenza, Adolfo G; Vázquez-Miranda, Hernán; Hernández-Alonso, Germán; García-Trejo, Erick A; Sánchez-González, Luis A

    2017-07-01

    Phylogenetic relationships and patterns of evolution within Melanerpes, one of the most diverse groups of New World woodpeckers (22-23 lineages), have been complicated due to complex plumages and morphological adaptations. In an attempt to resolve these issues, we obtained sequence data from four nuclear introns and two mitochondrial protein-coding genes for 22 of the 24 currently recognized species in the genus. We performed phylogenetic analyses involving Maximum Likelihood and Bayesian Inference, species-tree divergence dating, and biogeographic reconstructions. Tree topologies from the concatenated and species-tree analyses of the mtDNA and nDNA showed broadly similar patterns, with three relatively well-supported groups apparent: (a) the Sphyrapicus clade (four species); (b) the typical Melanerpes clade, which includes temperate and subtropical dry forest black-backed species; and (c) the mostly barred-backed species, here referred to as the "Centurus" clade. The phylogenetic position of Melanerpes superciliaris regarding the rest of Melanerpes is ambiguous as it is recovered as sister to the rest of Melanerpes or as sister to a group including Sphyrapicus+Melanerpes. Our species tree estimations recovered the same well-delimited highly-supported clades. Geographic range evolution (estimated in BioGeoBEARS) was best explained by a DIVALIKE+j model, which includes vicariance, founder effect speciation, and anagenetic dispersal (range expansion) as important processes involved in the diversification of the largest radiation of woodpeckers in the New World. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Psyche's UV Reflectance Spectra: Exploring the origins of the largest exposed-core metallic asteroid

    Science.gov (United States)

    Becker, Tracy

    2016-10-01

    (16) Psyche is the largest of the M-class asteroids, and is presumed to be the exposed core of a differentiated asteroid stripped of its mantle through hit-and-run collisions. However, other origins for Psyche have been proposed, including that it formed from a highly-reduced, metal rich material in the inner solar system or that its surface is olivine that has been space weathered. If (16) Psyche is an exposed core, then studying its properties enhances our understanding of the cores of all terrestrial planets, including the Earth's. If it accreted in the inner part of the solar system and was later injected into the asteroid belt, then Psyche sheds light on the conditions and subsequent evolution of the early solar system. Lastly, if Psyche is weathered olivine, then olivine may be more abundant in the solar system than currently measured, rectifying the so-called Great Dunite Shortage. Our program to obtain high-resolution UV spectra of Psyche with the COS G140L mode and the STIS NUV MAMA G230L mode to measure spectral signatures between 90 - 315 nm is designed to distinguish between the 3 hypothesized cases. These observations will enable identification of absorption bands, especially Fe-O charge transfer bands and will be sensitive to spectral blueing that occurs at UV wavelengths for space-weathered objects. When combined, the presence of these UV features, or not, provides a novel test of Psyche formation theories.

  7. Carbon footprint of premium quality export bananas: case study in Ecuador, the world's largest exporter.

    Science.gov (United States)

    Iriarte, Alfredo; Almeida, Maria Gabriela; Villalobos, Pablo

    2014-02-15

    Nowadays, the new international market demands challenge the food producing countries to include the measurement of the environmental impact generated along the production process for their products. In order to comply with the environmentally responsible market requests the measurement of the greenhouse gas emissions of Ecuadorian agricultural goods has been promoted employing the carbon footprint concept. Ecuador is the largest exporter of bananas in the world. Within this context, this study is a first assessment of the carbon footprint of the Ecuadorian premium export banana (Musa AAA) using a considerable amount of field data. The system boundaries considered from agricultural production to delivery in a European destination port. The data collected over three years permitted identifying the hot spot stages. For the calculation, the CCaLC V3.0 software developed by the University of Manchester is used. The carbon footprint of the Ecuadorian export banana ranged from 0.45 to 1.04 kg CO2-equivalent/kg banana depending on the international overseas transport employed. The principal contributors to the carbon footprint are the on farm production and overseas transport stages. Mitigation and reduction strategies were suggested for the main emission sources in order to achieve sustainable banana production. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Characterization of the largest relic Eurasian wild grapevine reservoir in Southern Iberian Peninsula

    Energy Technology Data Exchange (ETDEWEB)

    Arroyo-García, R.; Cantos, M.; Lara, M.; López, M.A.; Gallardo, A.; Ocete, C.A.; Pérez, A.; Bánáti, B.; García, J.L.; Ocete, R.

    2016-11-01

    Wild grapevine is becoming a threatened species in the Iberian Peninsula due to human impacts. The aim of this work was to carry out a holistic study for six years of the largest wild grapevine population found up to date in SW Iberian Peninsula. This population has 115 vines. Ampelographic and soil characteristics have been studied. Evaluation of its environment has also been studied by describing the main parasitic species and natural enemies of pests. The ability of this plant material for its micropropagation and storage in slow-growth conditions has been tested. Microvinification resulted in a wine with good acidity and medium color intensity, two interesting characteristics under a warm climatology. Finally, the identification of private alleles in this wild population, absent in other locations from the Northern and Southern Iberian territories, is a very valuable feature and confirms the importance of establishing conservation programs. The population here studied is genetically unique and potentially useful for commercial rootstocks and cultivars breeding that would improve viticulture and enology. (Author)

  9. State-owned companies dominate list of largest non-U.S. producers

    International Nuclear Information System (INIS)

    Beck, R.J.; Williamson, M.

    1994-01-01

    Because state-owned oil and gas companies dominate Oil and Gas Journal's list of largest non-US producers, data aren't fully comparable with those of the OGJ300. Many state companies report only production and reserves, with little or no financial data. Companies on the OGJ100, therefore, cannot be ranked by assets or revenues. Instead, they are listed by regions, based on location of corporate headquarters. There was no change in makeup of the top 20 holders of crude oil reserves. These companies' reserves totaled 872.3 billion bbl in 1993. The top 20 non-US companies now control 87.3 % of total world crude oil reserves, according to OGJ estimates. This is up marginally from 87.2 % of total world oil reserves in 1992. The top 20 had 87.7 % of total world reserves in 1991 and 85.5 % in 1990. The table lists company name, total assets, revenues, net income, capital and exploratory expenditures, worldwide oil production, gas production, oil and gas reserves worldwide

  10. Estimation of the largest enterprises’ impact on the socio-economic development of territories

    Directory of Open Access Journals (Sweden)

    Ekaterina Dmitrievna Razgulina

    2014-07-01

    Full Text Available The key basic trends of modern society development are associated with the transfer of some government functions to big business. Thus, scientific and public circles argue about social partnership between government, business and employees and offer different variants of the corporate social responsibility concept. The article presents the experience to assess social responsibility of business on the example of the largest chemical enterprises located in the Vologda and Novgorod oblasts. The evaluation results have revealed a number of problems hindering the formation of socially responsible behavior of enterprises, particularly the lack of standardized reporting on corporate social responsibility; provision of formal corporate social responsibility report; business’ non-system participation in social and economic development of territories. According to the authors, the development of a special model to regulate participants’ mutual relations can increase social responsibility of Russian business. Unified interests and resources of business and government promote the development of an agreed strategy in the field of regional social-economic development

  11. Evaluation of several priority pollutants in zebra mussels (Dreissena polymorpha) in the largest Italian subalpine lakes

    International Nuclear Information System (INIS)

    Riva, Consuelo; Binelli, Andrea; Provini, Alfredo

    2008-01-01

    Zebra mussel (Dreissena polymorpha) has been used for the biomonitoring of several POPs (PCBs, DDTs, HCB and HCHs) in the largest Italian subalpine great lakes (Lake Maggiore, Garda, Como, Iseo and Lugano). Samplings were carried out in April 2003 at 15 locations selected according to industrial and anthropic levels of lakes. Results have pointed out high DDT levels in D. polymorpha specimens from Lake Maggiore (700-1400 ng/g lipids, 5-9 times higher than those measured in mussels of other Italian lakes), due to a contamination from a chemical plant located on one of the main lake inlet that occurred in 1996. On the contrary, PCB levels (400-2509 ng/g lipids) highlighted an overall pollution, with some sporadic peaks of contamination. Data showed a moderate increase trend compared to those found in a previous monitoring campaign carried out in 1996. Future monitoring is needed in order to confirm this tendency. - Significant levels of DDTs and PCBs are still present in the Italian subalpine great lakes

  12. Evaluation of several priority pollutants in zebra mussels (Dreissena polymorpha) in the largest Italian subalpine lakes

    Energy Technology Data Exchange (ETDEWEB)

    Riva, Consuelo [Department of Biology, Ecology Section, University of Milan, Via Celoria 26, 20133 Milan (Italy)], E-mail: consuelo.riva@unimi.it; Binelli, Andrea; Provini, Alfredo [Department of Biology, Ecology Section, University of Milan, Via Celoria 26, 20133 Milan (Italy)

    2008-02-15

    Zebra mussel (Dreissena polymorpha) has been used for the biomonitoring of several POPs (PCBs, DDTs, HCB and HCHs) in the largest Italian subalpine great lakes (Lake Maggiore, Garda, Como, Iseo and Lugano). Samplings were carried out in April 2003 at 15 locations selected according to industrial and anthropic levels of lakes. Results have pointed out high DDT levels in D. polymorpha specimens from Lake Maggiore (700-1400 ng/g lipids, 5-9 times higher than those measured in mussels of other Italian lakes), due to a contamination from a chemical plant located on one of the main lake inlet that occurred in 1996. On the contrary, PCB levels (400-2509 ng/g lipids) highlighted an overall pollution, with some sporadic peaks of contamination. Data showed a moderate increase trend compared to those found in a previous monitoring campaign carried out in 1996. Future monitoring is needed in order to confirm this tendency. - Significant levels of DDTs and PCBs are still present in the Italian subalpine great lakes.

  13. Monitoring coastal pollution associated with the largest oil refinery complex of Venezuela

    Directory of Open Access Journals (Sweden)

    Aldo Croquer

    2016-06-01

    Full Text Available This study evaluated pollution levels in water and sediments of Península de Paraguaná and related these levels with benthic macrofauna along a coastal area where the largest Venezuelan oil refineries have operated over the past 60 years. For this, the concentration of heavy metals, of hydrocarbon compounds and the community structure of the macrobenthos were examined at 20 sites distributed along 40 km of coastline for six consecutive years, which included windy and calm seasons. The spatial variability of organic and inorganic compounds showed considerably high coastal pollution along the study area, across both years and seasons. The southern sites, closest to the refineries, had consistently higher concentrations of heavy metals and organic compounds in water and sediments when compared to those in the north. The benthic community was dominated by polychaetes at all sites, seasons and years, and their abundance and distribution were significantly correlated with physical and chemical characteristics of the sediments. Sites close to the oil refineries were consistently dominated by families known to tolerate xenobiotics, such as Capitellidae and Spionidae. The results from this study highlight the importance of continuing long-term environmental monitoring programs to assess the impact of effluent discharge and spill events from the oil refineries that operate in the western coast of Paraguaná, Venezuela.

  14. Hydrodynamic and Inundation Modeling of China’s Largest Freshwater Lake Aided by Remote Sensing Data

    Directory of Open Access Journals (Sweden)

    Peng Zhang

    2015-04-01

    Full Text Available China’s largest freshwater lake, Poyang Lake, is characterized by rapid changes in its inundation area and hydrodynamics, so in this study, a hydrodynamic model of Poyang Lake was established to simulate these long-term changes. Inundation information was extracted from Moderate Resolution Imaging Spectroradiometer (MODIS remote sensing data and used to calibrate the wetting and drying parameter by assessing the accuracy of the simulated inundation area and its boundary. The bottom friction parameter was calibrated using current velocity measurements from Acoustic Doppler Current Profilers (ADCP. The results show the model is capable of predicting the inundation area dynamic through cross-validation with remotely sensed inundation data, and can reproduce the seasonal dynamics of the water level, and water discharge through a comparison with hydrological data. Based on the model results, the characteristics of the current velocities of the lake in the wet season and the dry season of the lake were explored, and the potential effect of the current dynamic on water quality patterns was discussed. The model is a promising basic tool for prediction and management of the water resource and water quality of Poyang Lake.

  15. Bedrock Canyons Carved by the Largest Known Floods on Earth and Mars

    Science.gov (United States)

    Lamb, M. P.; Lapôtre, M. G. A.; Larsen, I. J.; Williams, R. M. E.

    2017-12-01

    The surface of Earth is a dynamic and permeable interface where the rocky crust is sculpted by ice, wind and water resulting in spectacular mountain ranges, vast depositional basins and environments that support life. These landforms and deposits contain a rich, yet incomplete, record of Earth history that we are just beginning to understand. Some of the most dramatic landforms are the huge bedrock canyons carved by catastrophic floods. On Mars, similar bedrock canyons, known as Outflow Channels, are the most important indicators of large volumes of surface water in the past. Despite their importance and now decades of observations of canyon morphology, we lack a basic understanding of how the canyons formed, which limits our ability to reconstruct flood discharge, duration and water volume. In this presentation I will summarize recent work - using mechanistic numerical models and field observations - that suggests that bedrock canyons carved by megafloods rapidly evolve to a size and shape such that boundary shear stresses just exceed that required to entrain fractured blocks of rock. The threshold shear stress constraint allows for quantitative reconstruction of the largest known floods on Earth and Mars, and implies far smaller discharges than previous methods that assume flood waters fully filled the canyons to high water marks.

  16. KEPLER-1647B: THE LARGEST AND LONGEST-PERIOD KEPLER TRANSITING CIRCUMBINARY PLANET

    International Nuclear Information System (INIS)

    Kostov, Veselin B.; Orosz, Jerome A.; Welsh, William F.; Short, Donald R.; Doyle, Laurance R.; Fabrycky, Daniel C.; Haghighipour, Nader; Quarles, Billy; Cochran, William D.; Endl, Michael; Ford, Eric B.; Gregorio, Joao; Hinse, Tobias C.; Isaacson, Howard; Jenkins, Jon M.; Jensen, Eric L. N.; Kane, Stephen; Kull, Ilya

    2016-01-01

    We report the discovery of a new Kepler transiting circumbinary planet (CBP). This latest addition to the still-small family of CBPs defies the current trend of known short-period planets orbiting near the stability limit of binary stars. Unlike the previous discoveries, the planet revolving around the eclipsing binary system Kepler-1647 has a very long orbital period (∼1100 days) and was at conjunction only twice during the Kepler mission lifetime. Due to the singular configuration of the system, Kepler-1647b is not only the longest-period transiting CBP at the time of writing, but also one of the longest-period transiting planets. With a radius of 1.06 ± 0.01 R Jup , it is also the largest CBP to date. The planet produced three transits in the light curve of Kepler-1647 (one of them during an eclipse, creating a syzygy) and measurably perturbed the times of the stellar eclipses, allowing us to measure its mass, 1.52 ± 0.65 M Jup . The planet revolves around an 11-day period eclipsing binary consisting of two solar-mass stars on a slightly inclined, mildly eccentric ( e bin = 0.16), spin-synchronized orbit. Despite having an orbital period three times longer than Earth’s, Kepler-1647b is in the conservative habitable zone of the binary star throughout its orbit.

  17. Seasonal variations of trace elements in precipitation at the largest city in Tibet, Lhasa

    Science.gov (United States)

    Guo, Junming; Kang, Shichang; Huang, Jie; Zhang, Qianggong; Tripathee, Lekhendra; Sillanpää, Mika

    2015-02-01

    Precipitation samples were collected from March 2010 to August 2012 at an urban site in Lhasa, the capital and largest city of Tibet. The volume weighted mean (VWM) concentrations of 17 trace elements in precipitation were higher during the non-monsoon season than in the monsoon season, but inverse seasonal variations occurred for wet deposition fluxes of most of the trace elements. Concentrations for most of trace elements were negatively correlated with precipitation amount, indicating that below-cloud scavenging of trace elements was an important mechanism contributing to wet deposition of these elements. The elements Al, Sc, V, Cr, Mn, Fe, Mn, Ni, and U displayed low crustal enrichment factors (EFs), whereas Co, Cu, Zn, As, Cd Sn, Pb, and Bi showed high EF values in precipitation, suggesting that anthropogenic activities might be important contributors of these elements at Lhasa. However, this present work indicates a much lower anthropogenic emission at Lhasa than in seriously polluted regions. Our study will not only provide insights for assessing the current status of the atmospheric environment in Lhasa but also enhance our understanding for updating the baseline for environmental protection over the Tibetan Plateau.

  18. The largest subsea hot tap (future tap flange) at Angel Field, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Lad, Deepak; Drysdale, Colin [T.D. Williamson (United States); Naidoo, Sashie [T.D. Williamson (Australia)

    2008-07-01

    A subsea hot tap was conducted near the gas production platforms in Angel Field, Australia in September 2007 and verified as the largest no. 900 subsea hot tap by Australian authorities. This paper outlines the subsea tapping process, risks and safety issues in deep water environment, including the need to ensure 100% system accuracy and that the machine fluids used to operate the subsea tapping machines were environmentally friendly. The testing phase included land and water testing. In the land tests, issues relating to metal hardness, temperature, pressure and ocean currents that affected machine stability, torque and cutting rate were considered. All preliminary design and testing focused on being able to mount the tapping machine to a pre-existing hot-tap flange and conduct the tapping operation, start to finish, preferably without changing the cutter. The water depth tests took place inside a pressurized, underwater hyperbaric chamber. The equipment repeated the land testing process in conditions duplicating that of the actual project site. Timing was also measured in multiple climatic conditions (except water depth) to obtain an estimation of various scenarios. The field tapping process was conducted without problems in over six hours with a single cutter and without any stalls. (author)

  19. Dragon bridge - the world largest dragon-shaped (ARCH steel bridge as element of smart city

    Directory of Open Access Journals (Sweden)

    Chinh Luong Minh

    2016-01-01

    Full Text Available Dragon Bridge - The world’s largest dragon-shaped steel bridge, with an installation cost of $85 million USD, features 6 lanes for two separate directions, 666 meters of undulating steel in the shape of a dragon in the Ly Dynasty, the symbol of prosperity in Vietnamese culture. This unique and beautifully lit bridge, which also breathes fire and sprays water. It’s the purposeful integration of the lighting hardware articulates the dragon’s form, and the fire-breathing dragon head. This project transcends the notion of monumental bridge with dynamic colour-changing lighting, creating an iconic sculpture in the skyline that is both reverent and whimsical. The signature feature of the bridge was the massive undulating support structure resembling a dragon flying over the river. The dragon is prominent in Vietnamese culture as a symbol of power and nobility. Dragon Bridge stands out as a model of innovation. It has received worldwide attention in the design community and from the global media for its unique arch support system. Dragon Bridge serves as an example of how aesthetic quality of a design can serve cultural, economic and functional purposes. The article presents design solutions of the object and the evaluation of the technical condition before putting the facility into service.

  20. Astronomer's new guide to the galaxy: largest map of cold dust revealed

    Science.gov (United States)

    2009-07-01

    Astronomers have unveiled an unprecedented new atlas of the inner regions of the Milky Way, our home galaxy, peppered with thousands of previously undiscovered dense knots of cold cosmic dust -- the potential birthplaces of new stars. Made using observations from the APEX telescope in Chile, this survey is the largest map of cold dust so far, and will prove an invaluable map for observations made with the forthcoming ALMA telescope, as well as the recently launched ESA Herschel space telescope. ESO PR Photo 24a/09 View of the Galactic Plane from the ATLASGAL survey (annotated and in five sections) ESO PR Photo 24b/09 View of the Galactic Plane from the ATLASGAL survey (annotated) ESO PR Photo 24c/09 View of the Galactic Plane from the ATLASGAL survey (in five sections) ESO PR Photo 24d/09 View of the Galactic Plane from the ATLASGAL survey ESO PR Photo 24e/09 The Galactic Centre and Sagittarius B2 ESO PR Photo 24f/09 The NGC 6357 and NGC 6334 nebulae ESO PR Photo 24g/09 The RCW120 nebula ESO PR Video 24a/09 Annotated pan as seen by the ATLASGAL survey This new guide for astronomers, known as the APEX Telescope Large Area Survey of the Galaxy (ATLASGAL) shows the Milky Way in submillimetre-wavelength light (between infrared light and radio waves [1]). Images of the cosmos at these wavelengths are vital for studying the birthplaces of new stars and the structure of the crowded galactic core. "ATLASGAL gives us a new look at the Milky Way. Not only will it help us investigate how massive stars form, but it will also give us an overview of the larger-scale structure of our galaxy", said Frederic Schuller from the Max Planck Institute for Radio Astronomy, leader of the ATLASGAL team. The area of the new submillimetre map is approximately 95 square degrees, covering a very long and narrow strip along the galactic plane two degrees wide (four times the width of the full Moon) and over 40 degrees long. The 16 000 pixel-long map was made with the LABOCA submillimetre

  1. Subcellular localization of pituitary enzymes

    Science.gov (United States)

    Smith, R. E.

    1970-01-01

    A cytochemical procedure is reported for identifying subcellular sites of enzymes hydrolyzing beta-naphthylamine substrates, and to study the sites of reaction product localization in cells of various tissues. Investigations using the substrate Leu 4-methoxy-8-naphthylamine, a capture with hexonium pararosaniline, and the final chelation of osmium have identified the hydrolyzing enzyme of rat liver cells; this enzyme localized on cell membranes with intense deposition in the areas of the parcanaliculi. The study of cells in the anterior pituitary of the rat showed the deposition of reaction product on cell membrane; and on the membranes of secretion granules contained within the cell. The deposition of reaction product on the cell membrane however showed no increase or decrease with changes in the physiological state of the gland and release of secretion granules from specific cells.

  2. Enzymes in CO2 Capture

    DEFF Research Database (Denmark)

    Fosbøl, Philip Loldrup; Gladis, Arne; Thomsen, Kaj

    The enzyme Carbonic Anhydrase (CA) can accelerate the absorption rate of CO2 into aqueous solutions by several-fold. It exist in almost all living organisms and catalyses different important processes like CO2 transport, respiration and the acid-base balances. A new technology in the field...... of carbon capture is the application of enzymes for acceleration of typically slow ternary amines or inorganic carbonates. There is a hidden potential to revive currently infeasible amines which have an interesting low energy consumption for regeneration but too slow kinetics for viable CO2 capture. The aim...... of this work is to discuss the measurements of kinetic properties for CA promoted CO2 capture solvent systems. The development of a rate-based model for enzymes will be discussed showing the principles of implementation and the results on using a well-known ternary amine for CO2 capture. Conclusions...

  3. Substrate mediated enzyme prodrug therapy

    DEFF Research Database (Denmark)

    Fejerskov, Betina; Jarlstad Olesen, Morten T; Zelikin, Alexander N

    2017-01-01

    Substrate mediated enzyme prodrug therapy (SMEPT) is a biomedical platform developed to perform a localized synthesis of drugs mediated by implantable biomaterials. This approach combines the benefits and at the same time offers to overcome the drawbacks for traditional pill-based drug administra......Substrate mediated enzyme prodrug therapy (SMEPT) is a biomedical platform developed to perform a localized synthesis of drugs mediated by implantable biomaterials. This approach combines the benefits and at the same time offers to overcome the drawbacks for traditional pill-based drug...

  4. The Largest Bio-Silica Structure on Earth: The Giant Basal Spicule from the Deep-Sea Glass Sponge Monorhaphis chuni

    Directory of Open Access Journals (Sweden)

    Xiaohong Wang

    2011-01-01

    Full Text Available The depth of the ocean is plentifully populated with a highly diverse fauna and flora, from where the Challenger expedition (1873–1876 treasured up a rich collection of vitreous sponges [Hexactinellida]. They have been described by Schulze and represent the phylogenetically oldest class of siliceous sponges [phylum Porifera]; they are eye-catching because of their distinct body plan, which relies on a filigree skeleton. It is constructed by an array of morphologically determined elements, the spicules. Later, during the German Deep Sea Expedition “Valdivia” (1898-1899, Schulze could describe the largest siliceous hexactinellid sponge on Earth, the up to 3 m high Monorhaphis chuni, which develops the equally largest bio-silica structures, the giant basal spicules (3 m × 10 mm. With such spicules as a model, basic knowledge on the morphology, formation, and development of the skeletal elements could be elaborated. Spicules are formed by a proteinaceous scaffold which mediates the formation of siliceous lamellae in which the proteins are encased. Up to eight hundred 5 to 10 μm thick lamellae can be concentrically arranged around an axial canal. The silica matrix is composed of almost pure silicon and oxygen, providing it with unusual optophysical properties that are superior to those of man-made waveguides. Experiments indicated that the spicules function in vivo as a nonocular photoreception system. In addition, the spicules have exceptional mechanical properties, combining mechanical stability with strength and stiffness. Like demosponges the hexactinellids synthesize their silica enzymatically, via the enzyme silicatein. All these basic insights will surely contribute also to a further applied utilization and exploration of bio-silica in material/medical science.

  5. The largest Bio-Silica Structure on Earth: The Giant Basal Spicule from the Deep-Sea Glass Sponge Monorhaphis chuni.

    Science.gov (United States)

    Wang, Xiaohong; Gan, Lu; Jochum, Klaus P; Schröder, Heinz C; Müller, Werner E G

    2011-01-01

    The depth of the ocean is plentifully populated with a highly diverse fauna and flora, from where the Challenger expedition (1873-1876) treasured up a rich collection of vitreous sponges [Hexactinellida]. They have been described by Schulze and represent the phylogenetically oldest class of siliceous sponges [phylum Porifera]; they are eye-catching because of their distinct body plan, which relies on a filigree skeleton. It is constructed by an array of morphologically determined elements, the spicules. Later, during the German Deep Sea Expedition "Valdivia" (1898-1899), Schulze could describe the largest siliceous hexactinellid sponge on Earth, the up to 3 m high Monorhaphis chuni, which develops the equally largest bio-silica structures, the giant basal spicules (3 m × 10 mm). With such spicules as a model, basic knowledge on the morphology, formation, and development of the skeletal elements could be elaborated. Spicules are formed by a proteinaceous scaffold which mediates the formation of siliceous lamellae in which the proteins are encased. Up to eight hundred 5 to 10 μm thick lamellae can be concentrically arranged around an axial canal. The silica matrix is composed of almost pure silicon and oxygen, providing it with unusual optophysical properties that are superior to those of man-made waveguides. Experiments indicated that the spicules function in vivo as a nonocular photoreception system. In addition, the spicules have exceptional mechanical properties, combining mechanical stability with strength and stiffness. Like demosponges the hexactinellids synthesize their silica enzymatically, via the enzyme silicatein. All these basic insights will surely contribute also to a further applied utilization and exploration of bio-silica in material/medical science.

  6. Rewriting the Landform History of One of Africa's Three Largest Basins

    Science.gov (United States)

    Wilkinson, Justin

    2014-01-01

    The Kalahari Basin in southern Africa - one of the largest basins in Africa, along with the Congo and Chad basins - has attracted attention since David Livingstone traveled through the area in the 1840s. It is a semiarid desert with a large freshwater swampland known as the Okavango Swamp (150 km radius). This prominent megafan (a fan with radii >100 km), with its fingers of dark green forests projecting into the dun colors of the dunes of the Kalahari semi-desert, has been well photographed by astronauts over the years. The study area in the northern Kalahari basin is centered on the Okavango megafan of northwest Botswana, whose swampland has become well known as an African wildlife preserve of importance to biology and tourism alike. The Okavango River is unusual because it has deposited not one but two megafans along its course: the Okavango megafan and the Cubango megafan. The Okavango megafan is one of only three well-known megafans in Africa. Megafans on Earth were once thought to be rare, but recent research has documented 68 in Africa alone. Eleven megafans, plus three more candidates, have been documented in the area immediately surrounding the Okavango feature. These 11 megafans occupy the flattest and smoothest terrains adjacent to the neighboring upland and stand out as the darkest areas in the roughness map of the area. Megafan terrains occupy at least 200,000 sq km of the study area. The roughness map shown is based on an algorithm used first on Mars to quantify topographic roughness. Research of Earth's flattest terrains is just beginning with the aid of such maps, and it appears that these terrains are analogous to the flattest regions of Mars. Implications: 1. The variability in depositional style in each subbasin may apply Africa-wide: rift megafan length is dominated by rift width, whereas Owambo subbasin megafans are probably controlled by upland basin size; Zambezi subbasin megafans appear more like foreland basin types, with the position of

  7. Solar energy potential of the largest buildings in the United States

    Science.gov (United States)

    Wence, E. R.; Grodsky, S.; Hernandez, R. R.

    2017-12-01

    Sustainable pathways of land use for energy are necessary to mitigate climate change and limit conversion of finite land resources needed for conservation and food production. Large, commercial buildings (LCBs) are increasing in size and number throughout the United States (US) and may serve as suitable recipient environments for photovoltaic (PV) solar energy infrastructure that may support a low carbon, low land footprint energy transition. In this study, we identified, characterized, and evaluated the technical potential of the largest, commercial building rooftops (i.e., exceeding 110,000 m2) and their associated parking lots in the US for PV solar energy systems using Aurora, a cloud-based solar optimization platform. We also performed a case study of building-specific electricity generation: electricity consumption balance. Further, we quantified the environmental co-benefit of land sparing and associated avoided emissions (t-CO2-eq) conferred under the counterfactual scenario that solar development would otherwise proceed as a ground-mounted, utility-scale PV installation of equal nominal capacity. We identified and mapped 37 LCBs (by rooftop area) across 18 states in the US, spanning from as far north as the state of Minnesota to as far south as Florida. Rooftop footprints range from 427,297 to 113,689 m2 and have a cumulative surface area of 99.8 million ft2. We characterize the LCBs as either: distribution/warehouse, factory, shopping center, or administrative office/facility. Three of the 37 LCBs currently support rooftop PV and the numbers of associated, detached buildings number up to 38. This study elucidates the extent to which LCBs and their respective parking lots can serve as suitable sites for PV solar energy generation. Lastly, this study demonstrates research-based applications of the Aurora energy modeling platform and informs decision-making focused on redirecting energy development towards human-modified landscapes to prioritize land use for

  8. Indication and implementation of lipidapheresis, rheopheresis, or immunoadsorption (lessons learnt from Germany's largest apheresis center).

    Science.gov (United States)

    Heigl, Franz; Hettich, Reinhard; Lotz, Norbert; Reeg, Harduin; Eder, Bernadette; Steckholzer-Kroth, Karin; Browatzki, Michael; Harre, Kerstin; Arendt, Rainer

    2009-12-29

    Efficient modes of extracorporeal blood purification are available today for apheresis treatment of progressive atherosclerosis, autoimmune disease, or for improving hemorheology. Advanced technology and sophisticated care render apheresis treatment selective, safe and tolerable. Our task is to constantly update indications for apheresis based on best evidence available and good clinical practice, as well as, to determine how apheresis therapy can be made available to those in need or with otherwise refractory disease. Presenting examples of lipid apheresis, rheopheresis, or immunoadsorption for treatment of hypercholesterolemia, hyperlipoproteinemia (a), acute hearing loss, refractory or exacerbating multiple sclerosis, we highlight real world obstacles for implementation of treatment, resulting in still too many patients with proven or recommended indication left untreated. Based on the experience of the largest apheresis center in Germany, with more than 3,300 treatments per year, we depict the necessary structure for identification of patients, defining indication, referral, implementation of therapy, and reimbursement. Apheresis is unfamiliar to most patients and many practitioners or consultants. Nephrologists, performing >90% of apheresis treatments in Germany, have to form a network for referral comprising all regional care-givers, general practitioners as well as the respective specialists (mainly, cardiologists, endocrinologists, diabetologists, ORL specialists, neurologists, ophthalmologists, or rheumatologists), and insurances or other cost-bearing parties for offering a scientifically approved therapeutic regimen and comprehensive care. We have realized this concept in a high volume apheresis center acting in a closely knit network characterized by an unrelenting effort at ongoing medical education. As a consequence, we include approximately 10 times more patients with appropriate diagnoses in our apheresis program as compared to the national average

  9. Evidence for protection of targeted reef fish on the largest marine reserve in the Caribbean

    Directory of Open Access Journals (Sweden)

    Fabián Pina-Amargós

    2014-02-01

    Full Text Available Marine reserves can restore fish abundance and diversity in areas impacted by overfishing, but the effectiveness of reserves in developing countries where resources for enforcement are limited, have seldom been evaluated. Here we assess whether the establishment in 1996 of the largest marine reserve in the Caribbean, Gardens of the Queen in Cuba, has had a positive effect on the abundance of commercially valuable reef fish species in relation to neighboring unprotected areas. We surveyed 25 sites, including two reef habitats (reef crest and reef slope, inside and outside the marine reserve, on five different months, and over a one-and-a-half year period. Densities of the ten most frequent, highly targeted, and relatively large fish species showed a significant variability across the archipelago for both reef habitats that depended on the month of survey. These ten species showed a tendency towards higher abundance inside the reserve in both reef habitats for most months during the study. Average fish densities pooled by protection level, however, showed that five out of these ten species were at least two-fold significantly higher inside than outside the reserve at one or both reef habitats. Supporting evidence from previously published studies in the area indicates that habitat complexity and major benthic communities were similar inside and outside the reserve, while fishing pressure appeared to be homogeneous across the archipelago before reserve establishment. Although poaching may occur within the reserve, especially at the boundaries, effective protection from fishing was the most plausible explanation for the patterns observed.

  10. Phylogenetics and diversification of tanagers (Passeriformes: Thraupidae), the largest radiation of Neotropical songbirds.

    Science.gov (United States)

    Burns, Kevin J; Shultz, Allison J; Title, Pascal O; Mason, Nicholas A; Barker, F Keith; Klicka, John; Lanyon, Scott M; Lovette, Irby J

    2014-06-01

    Thraupidae is the second largest family of birds and represents about 4% of all avian species and 12% of the Neotropical avifauna. Species in this family display a wide range of plumage colors and patterns, foraging behaviors, vocalizations, ecotypes, and habitat preferences. The lack of a complete phylogeny for tanagers has hindered the study of this evolutionary diversity. Here, we present a comprehensive, species-level phylogeny for tanagers using six molecular markers. Our analyses identified 13 major clades of tanagers that we designate as subfamilies. In addition, two species are recognized as distinct branches on the tanager tree. Our topologies disagree in many places with previous estimates of relationships within tanagers, and many long-recognized genera are not monophyletic in our analyses. Our trees identify several cases of convergent evolution in plumage ornaments and bill morphology, and two cases of social mimicry. The phylogeny produced by this study provides a robust framework for studying macroevolutionary patterns and character evolution. We use our new phylogeny to study diversification processes, and find that tanagers show a background model of exponentially declining diversification rates. Thus, the evolution of tanagers began with an initial burst of diversification followed by a rate slowdown. In addition to this background model, two later, clade-specific rate shifts are supported, one increase for Darwin's finches and another increase for some species of Sporophila. The rate of diversification within these two groups is exceptional, even when compared to the overall rapid rate of diversification found within tanagers. This study provides the first robust assessment of diversification rates for the Darwin's finches in the context of the larger group within which they evolved. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Invertebrate population genetics across Earth's largest habitat: The deep-sea floor.

    Science.gov (United States)

    Taylor, M L; Roterman, C N

    2017-10-01

    Despite the deep sea being the largest habitat on Earth, there are just 77 population genetic studies of invertebrates (115 species) inhabiting non-chemosynthetic ecosystems on the deep-sea floor (below 200 m depth). We review and synthesize the results of these papers. Studies reveal levels of genetic diversity comparable to shallow-water species. Generally, populations at similar depths were well connected over 100s-1,000s km, but studies that sampled across depth ranges reveal population structure at much smaller scales (100s-1,000s m) consistent with isolation by adaptation across environmental gradients, or the existence of physical barriers to connectivity with depth. Few studies were ocean-wide (under 4%), and 48% were Atlantic-focused. There is strong emphasis on megafauna and commercial species with research into meiofauna, "ecosystem engineers" and other ecologically important species lacking. Only nine papers account for ~50% of the planet's surface (depths below 3,500 m). Just two species were studied below 5,000 m, a quarter of Earth's seafloor. Most studies used single-locus mitochondrial genes revealing a common pattern of non-neutrality, consistent with demographic instability or selective sweeps; similar to deep-sea hydrothermal vent fauna. The absence of a clear difference between vent and non-vent could signify that demographic instability is common in the deep sea, or that selective sweeps render single-locus mitochondrial studies demographically uninformative. The number of population genetics studies to date is miniscule in relation to the size of the deep sea. The paucity of studies constrains meta-analyses where broad inferences about deep-sea ecology could be made. © 2017 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

  12. Smart phone Acceptance among physicians: Application of structural equation modeling in Iranian largest university

    Directory of Open Access Journals (Sweden)

    Nematollahi M.

    2017-03-01

    Full Text Available Background: The present study aimed to determine attitudes and effective factors in the acceptance of smart phones by physicians of the largest University of Medical Sciences in the south of Iran. Methods: This cross-sectional study was performed using Structural Equation Modelling (SEM in 2014. Study participants included 200 physicians working in the hospitals of Shiraz University of Medical Sciences selected through two-stage stratified sampling, but 185 participants completed the study. The study data were collected using a researcher-made questionnaire completed through a 5-point Likert scale. The content validity of the questionnaire was confirmed by a panel of experts, its construct validity by confirmatory factor analysis, and its reliability by Cronbach’s alpha of 0.802. All data analyses were performed using SPSS (version 22 and LISREL (version 8.8. Results: Results showed that most physicians had a desirable attitude towards using smart phones. Besides, the results of SEM indicated a significant relationship between attitude and compatibility, observability, personal experience, voluntariness of use and perceived usefulness. Moreover, some important fitness indices revealed appropriate fitness of the study model (p=0.26, X2 /df=1.35, RMR=0.070, GFI=0.77, AGFI=0.71, NNFI=0.93, CFI=0.94. Conclusion: The results revealed that compatibility, observability, personal experience, voluntariness of use and perceived usefulness were effective in the physicians’ attitude towards using smart phones. Thus, by preparation of the required infrastructures, policymakers in the field of health technology can enhance the utilization of smart phones in hospitals.

  13. Negotiating place and gendered violence in Canada's largest open drug scene.

    Science.gov (United States)

    McNeil, Ryan; Shannon, Kate; Shaver, Laura; Kerr, Thomas; Small, Will

    2014-05-01

    Vancouver's Downtown Eastside is home to Canada's largest street-based drug scene and only supervised injection facility (Insite). High levels of violence among men and women have been documented in this neighbourhood. This study was undertaken to explore the role of violence in shaping the socio-spatial relations of women and 'marginal men' (i.e., those occupying subordinate positions within the drug scene) in the Downtown Eastside, including access to Insite. Semi-structured qualitative interviews were conducted with 23 people who inject drugs (PWID) recruited through the Vancouver Area Network of Drug Users, a local drug user organization. Interviews included a mapping exercise. Interview transcripts and maps were analyzed thematically, with an emphasis on how gendered violence shaped participants' spatial practices. Hegemonic forms of masculinity operating within the Downtown Eastside framed the everyday violence experienced by women and marginal men. This violence shaped the spatial practices of women and marginal men, in that they avoided drug scene milieus where they had experienced violence or that they perceived to be dangerous. Some men linked their spatial restrictions to the perceived 'dope quality' of neighbourhood drug dealers to maintain claims to dominant masculinities while enacting spatial strategies to promote safety. Environmental supports provided by health and social care agencies were critical in enabling women and marginal men to negotiate place and survival within the context of drug scene violence. Access to Insite did not motivate participants to enter into "dangerous" drug scene milieus but they did venture into these areas if necessary to obtain drugs or generate income. Gendered violence is critical in restricting the geographies of men and marginal men within the street-based drug scene. There is a need to scale up existing environmental interventions, including supervised injection services, to minimize violence and potential drug

  14. NEGOTIATING PLACE AND GENDERED VIOLENCE IN CANADA’S LARGEST OPEN DRUG SCENE

    Science.gov (United States)

    McNeil, Ryan; Shannon, Kate; Shaver, Laura; Kerr, Thomas; Small, Will

    2014-01-01

    Background Vancouver’s Downtown Eastside is home to Canada’s largest street-based drug scene and only supervised injection facility (Insite). High levels of violence among men and women have been documented in this neighbourhood. This study was undertaken to explore the role of violence in shaping the socio-spatial relations of women and ‘marginal men’ (i.e., those occupying subordinate positions within the drug scene) in the Downtown Eastside, including access to Insite. Methods Semi-structured qualitative interviews were conducted with 23 people who inject drugs (PWID) recruited through the Vancouver Area Network of Drug Users, a local drug user organization. Interviews included a mapping exercise. Interview transcripts and maps were analyzed thematically, with an emphasis on how gendered violence shaped participants’ spatial practices. Results Hegemonic forms of masculinity operating within the Downtown Eastside framed the everyday violence experienced by women and marginal men. This violence shaped the spatial practices of women and marginal men, in that they avoided drug scene milieus where they had experienced violence or that they perceived to be dangerous. Some men linked their spatial restrictions to the perceived 'dope quality' of neighbourhood drug dealers to maintain claims to dominant masculinities while enacting spatial strategies to promote safety. Environmental supports provided by health and social care agencies were critical in enabling women and marginal men to negotiate place and survival within the context of drug scene violence. Access to Insite did not motivate participants to enter into “dangerous” drug scene milieus but they did venture into these areas if necessary to obtain drugs or generate income. Conclusion Gendered violence is critical in restricting the geographies of men and marginal men within the street-based drug scene. There is a need to scale up existing environmental interventions, including supervised injection

  15. Geochemical characterization of the largest upland lake of the Brazilian Amazonia: Impact of provenance and processes

    Science.gov (United States)

    Sahoo, Prafulla Kumar; Guimarães, José Tasso Felix; Souza-Filho, Pedro Walfir Martins; da Silva, Marcio Sousa; Nascimento, Wilson, Júnior; Powell, Mike A.; Reis, Luiza Santos; Pessenda, Luiz Carlos Ruiz; Rodrigues, Tarcísio Magevski; da Silva, Delmo Fonseca; Costa, Vladimir Eliodoro

    2017-12-01

    Lake Três Irmãs (LTI), the largest upland lake in the Brazilian Amazonia, located in Serra dos Carajás, was characterized using multi-elemental and isotope geochemistry (δ13C and δ15N) to understand the significance of organic and inorganic sources, weathering and sedimentary processes on the distribution of elements in lake bottom (surficial) sediments. Carbon and nitrogen isotopes from sedimentary organic matter suggest C3 terrestrial plants (forests > canga vegetation), macrophytes and freshwater DOC as the main sources. Sediments are depleted in most of the major oxides (except Fe2O3 and P2O5) when compared to upper continental crust (UCC) and their spatial distribution is highly influenced by catchment lithology. Principal Component Analysis revealed that most of the trace elements (Ba, Sr, Rb, Sc, Th, U, Zr, Hf, Nb, Y, V, Cr, Ga, Co, Ni) and REEs are closely correlated with Al and Ti (PC1; Group-1), so their redistribution is less influenced by post-depositional process. This is due to their relative immobility and being hosted by Al-bearing minerals during laterization. High Chemical Index of Alteration (CIA), Mafic Index of Alteration (MIA) and Index of Laterization (IOL) values indicate intense chemical weathering at source areas, but the weathering transformation was better quantified by IOL. A-CN-K plot along with elemental ratios (Al/K, Ti/K, Ti/Zr, La/Al, Cr/Th, Co/Th, La/Sm, La/Gd, Zr/Y, and Eu/Eu*) as well as chondrite-normalized REE patterns show that the detritic sediments are mainly sourced from ferruginous laterites and soils in the catchment, which may have characteristics similar to mafic rocks.

  16. Effect of noise and filtering on largest Lyapunov exponent of time series associated with human walking.

    Science.gov (United States)

    Mehdizadeh, Sina; Sanjari, Mohammad Ali

    2017-11-07

    This study aimed to determine the effect of added noise, filtering and time series length on the largest Lyapunov exponent (LyE) value calculated for time series obtained from a passive dynamic walker. The simplest passive dynamic walker model comprising of two massless legs connected by a frictionless hinge joint at the hip was adopted to generate walking time series. The generated time series was used to construct a state space with the embedding dimension of 3 and time delay of 100 samples. The LyE was calculated as the exponential rate of divergence of neighboring trajectories of the state space using Rosenstein's algorithm. To determine the effect of noise on LyE values, seven levels of Gaussian white noise (SNR=55-25dB with 5dB steps) were added to the time series. In addition, the filtering was performed using a range of cutoff frequencies from 3Hz to 19Hz with 2Hz steps. The LyE was calculated for both noise-free and noisy time series with different lengths of 6, 50, 100 and 150 strides. Results demonstrated a high percent error in the presence of noise for LyE. Therefore, these observations suggest that Rosenstein's algorithm might not perform well in the presence of added experimental noise. Furthermore, findings indicated that at least 50 walking strides are required to calculate LyE to account for the effect of noise. Finally, observations support that a conservative filtering of the time series with a high cutoff frequency might be more appropriate prior to calculating LyE. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. The 100-C-7 Remediation Project. An Overview of One of DOE's Largest Remediation Projects - 13260

    International Nuclear Information System (INIS)

    Post, Thomas C.; Strom, Dean; Beulow, Laura

    2013-01-01

    The U.S. Department of Energy Richland Operations Office (RL), U.S. Environmental Protection Agency (EPA) and Washington Closure Hanford LLC (WCH) completed remediation of one of the largest waste sites in the U.S. Department of Energy complex. The waste site, 100-C-7, covers approximately 15 football fields and was excavated to a depth of 85 feet (groundwater). The project team removed a total of 2.3 million tons of clean and contaminated soil, concrete debris, and scrap metal. 100-C-7 lies in Hanford's 100 B/C Area, home to historic B and C Reactors. The waste site was excavated in two parts as 100-C-7 and 100-C-7:1. The pair of excavations appear like pit mines. Mining engineers were hired to design their tiered sides, with safety benches every 17 feet and service ramps which allowed equipment access to the bottom of the excavations. The overall cleanup project was conducted over a span of almost 10 years. A variety of site characterization, excavation, load-out and sampling methodologies were employed at various stages of remediation. Alternative technologies were screened and evaluated during the project. A new method for cost effectively treating soils was implemented - resulting in significant cost savings. Additional opportunities for minimizing waste streams and recycling were identified and effectively implemented by the project team. During the final phase of cleanup the project team applied lessons learned throughout the entire project to address the final, remaining source of chromium contamination. The C-7 cleanup now serves as a model for remediating extensive deep zone contamination sites at Hanford. (authors)

  18. HOT Faults", Fault Organization, and the Occurrence of the Largest Earthquakes

    Science.gov (United States)

    Carlson, J. M.; Hillers, G.; Archuleta, R. J.

    2006-12-01

    We apply the concept of "Highly Optimized Tolerance" (HOT) for the investigation of spatio-temporal seismicity evolution, in particular mechanisms associated with largest earthquakes. HOT provides a framework for investigating both qualitative and quantitative features of complex feedback systems that are far from equilibrium and punctuated by rare, catastrophic events. In HOT, robustness trade-offs lead to complexity and power laws in systems that are coupled to evolving environments. HOT was originally inspired by biology and engineering, where systems are internally very highly structured, through biological evolution or deliberate design, and perform in an optimum manner despite fluctuations in their surroundings. Though faults and fault systems are not designed in ways comparable to biological and engineered structures, feedback processes are responsible in a conceptually comparable way for the development, evolution and maintenance of younger fault structures and primary slip surfaces of mature faults, respectively. Hence, in geophysical applications the "optimization" approach is perhaps more aptly replaced by "organization", reflecting the distinction between HOT and random, disorganized configurations, and highlighting the importance of structured interdependencies that evolve via feedback among and between different spatial and temporal scales. Expressed in the terminology of the HOT concept, mature faults represent a configuration optimally organized for the release of strain energy; whereas immature, more heterogeneous fault networks represent intermittent, suboptimal systems that are regularized towards structural simplicity and the ability to generate large earthquakes more easily. We discuss fault structure and associated seismic response pattern within the HOT concept, and outline fundamental differences between this novel interpretation to more orthodox viewpoints like the criticality concept. The discussion is flanked by numerical simulations of a

  19. Dragon's paradise lost: palaeobiogeography, evolution and extinction of the largest-ever terrestrial lizards (Varanidae.

    Directory of Open Access Journals (Sweden)

    Scott A Hocknull

    Full Text Available BACKGROUND: The largest living lizard species, Varanus komodoensis Ouwens 1912, is vulnerable to extinction, being restricted to a few isolated islands in eastern Indonesia, between Java and Australia, where it is the dominant terrestrial carnivore. Understanding how large-bodied varanids responded to past environmental change underpins long-term management of V. komodoensis populations. METHODOLOGY/PRINCIPAL FINDINGS: We reconstruct the palaeobiogeography of Neogene giant varanids and identify a new (unnamed species from the island of Timor. Our data reject the long-held perception that V. komodoensis became a giant because of insular evolution or as a specialist hunter of pygmy Stegodon. Phyletic giantism, coupled with a westward dispersal from mainland Australia, provides the most parsimonious explanation for the palaeodistribution of V. komodoensis and the newly identified species of giant varanid from Timor. Pliocene giant varanid fossils from Australia are morphologically referable to V. komodoensis suggesting an ultimate origin for V. komodoensis on mainland Australia (>3.8 million years ago. Varanus komodoensis body size has remained stable over the last 900,000 years (ka on Flores, a time marked by major faunal turnovers, extinction of the island's megafauna, the arrival of early hominids by 880 ka, co-existence with Homo floresiensis, and the arrival of modern humans by 10 ka. Within the last 2000 years their populations have contracted severely. CONCLUSIONS/SIGNIFICANCE: Giant varanids were once a ubiquitous part of Subcontinental Eurasian and Australasian faunas during the Neogene. Extinction played a pivotal role in the reduction of their ranges and diversity throughout the late Quaternary, leaving only V. komodoensis as an isolated long-term survivor. The events over the last two millennia now threaten its future survival.

  20. Nature Appropriation and Associations with Population Health in Canada’s Largest Cities

    Directory of Open Access Journals (Sweden)

    Timothy Jason

    2013-03-01

    Full Text Available Earth is a finite system with a limited supply of resources. As the human population grows, so does the appropriation of Earth’s natural capital, thereby exacerbating environmental concerns such as biodiversity loss, increased pollution, deforestation and global warming. Such concerns will negatively impact human health although it is widely believed that improving socio-economic circumstances will help to ameliorate environmental impacts and improve health outcomes. However, this belief does not explicitly acknowledge the fact that improvements in socio-economic position are reliant on increased inputs from nature. Gains in population health, particularly through economic means, are disconnected from the appropriation of nature to create wealth so that health gains become unsustainable. The current study investigated the sustainability of human population health in Canada with regard to resource consumption or “ecological footprints” (i.e., the resources required to sustain a given population. Ecological footprints of the 20 largest Canadian cities, along with several important determinants of health such as income and education, were statistically compared with corresponding indicators of human population health outcomes. A significant positive relationship was found between ecological footprints and life expectancy, as well as a significant negative relationship between ecological footprints and the prevalence of high blood pressure. Results suggest that increased appropriation of nature is linked to improved health outcomes. To prevent environmental degradation from excessive appropriation of natural resources will require the development of health promotion strategies that are de-coupled from ever-increasing and unsustainable resource use. Efforts to promote population health should focus on health benefits achieved from a lifestyle based on significantly reduced consumption of natural resources.

  1. Solomon Islands largest hawksbill turtle rookery shows signs of recovery after 150 years of excessive exploitation.

    Directory of Open Access Journals (Sweden)

    Richard J Hamilton

    Full Text Available The largest rookery for hawksbill turtles in the oceanic South Pacific is the Arnavon Islands, which are located in the Manning Strait between Isabel and Choiseul Province, Solomon Islands. The history of this rookery is one of overexploitation, conflict and violence. Throughout the 1800s Roviana headhunters from New Georgia repeatedly raided the Manning Strait to collect hawksbill shell which they traded with European whalers. By the 1970s the Arnavons hawksbill population was in severe decline and the national government intervened, declaring the Arnavons a sanctuary in 1976. But this government led initiative was short lived, with traditional owners burning down the government infrastructure and resuming intensive harvesting in 1982. In 1991 routine beach monitoring and turtle tagging commenced at the Arnavons along with extensive community consultations regarding the islands' future, and in 1995 the Arnavon Community Marine Conservation Area (ACMCA was established. Around the same time national legislation banning the sale of all turtle products was passed. This paper represents the first analysis of data from 4536 beach surveys and 845 individual turtle tagging histories obtained from the Arnavons between 1991-2012. Our results and the results of others, reveal that many of the hawksbill turtles that nest at the ACMCA forage in distant Australian waters, and that nesting on the Arnavons occurs throughout the year with peak nesting activity coinciding with the austral winter. Our results also provide the first known evidence of recovery for a western pacific hawksbill rookery, with the number of nests laid at the ACMCA and the remigration rates of turtles doubling since the establishment of the ACMCA in 1995. The Arnavons case study provides an example of how changes in policy, inclusive community-based management and long term commitment can turn the tide for one of the most charismatic and endangered species on our planet.

  2. Lessons Learned in Deploying the World s Largest Scale Lustre File System

    Energy Technology Data Exchange (ETDEWEB)

    Dillow, David A [ORNL; Fuller, Douglas [ORNL; Wang, Feiyi [ORNL; Oral, H Sarp [ORNL; Zhang, Zhe [ORNL; Hill, Jason J [ORNL; Shipman, Galen M [ORNL

    2010-01-01

    The Spider system at the Oak Ridge National Laboratory's Leadership Computing Facility (OLCF) is the world's largest scale Lustre parallel file system. Envisioned as a shared parallel file system capable of delivering both the bandwidth and capacity requirements of the OLCF's diverse computational environment, the project had a number of ambitious goals. To support the workloads of the OLCF's diverse computational platforms, the aggregate performance and storage capacity of Spider exceed that of our previously deployed systems by a factor of 6x - 240 GB/sec, and 17x - 10 Petabytes, respectively. Furthermore, Spider supports over 26,000 clients concurrently accessing the file system, which exceeds our previously deployed systems by nearly 4x. In addition to these scalability challenges, moving to a center-wide shared file system required dramatically improved resiliency and fault-tolerance mechanisms. This paper details our efforts in designing, deploying, and operating Spider. Through a phased approach of research and development, prototyping, deployment, and transition to operations, this work has resulted in a number of insights into large-scale parallel file system architectures, from both the design and the operational perspectives. We present in this paper our solutions to issues such as network congestion, performance baselining and evaluation, file system journaling overheads, and high availability in a system with tens of thousands of components. We also discuss areas of continued challenges, such as stressed metadata performance and the need for file system quality of service alongside with our efforts to address them. Finally, operational aspects of managing a system of this scale are discussed along with real-world data and observations.

  3. Iceland as the largest source of natural air pollution in the Arctic

    Science.gov (United States)

    Dagsson Waldhauserova, Pavla; Meinander, Outi; Olafsson, Haraldur; Arnalds, Olafur

    2017-04-01

    Arctic aerosols are often attributed to the Arctic Haze and long-range transport tracers. There is, however, an important dust source in the Arctic/Sub-arctic region which should receive more attention. The largest desert in the Arctic as well as in the Europe is Iceland with > 40,000 km2 of desert areas. The mean dust suspension frequency was 135 dust days annually in 1949-2012 with decreasing numbers in 2013-2015. The annual dust deposition was calculated as 31-40 million tons yr-1 affecting the area of > 500,000 km2. Satelite MODIS pictures have revealed dust plumes traveling > 1000 km at times. The physical properties of Icelandic dust showed differences in mineralogy, geochemical compositions, shapes, sizes, and colour, compared to the crustal mineral dust. Icelandic dust is of volcanic origin, dark in colour with sharp-tipped shards and large bubbles. About 80% of the particulate matter is volcanic glass rich in heavy metals, such as iron and titanium. Suspended dust measured at the glacial dust source consisted of such high number of close-to-ultrafine particles as concentrations during active eruptions. Generally, about 50% of the suspended PM10 are submicron particles in Iceland. Contrarily, suspended grains > 2 mm were captured during severe dust storm after the 2010 Eyjafjallajokull eruption when the aeolian transport exceeded 11 t m-1 of materials and placed this storms among the most extreme wind erosion events recorded on Earth. Our reflectance measurements showed that Icelandic dust deposited on snow lowers the snow albedo and reduces the snow density as much as Black Carbon. Icelandic volcanic dust tends to act as a positive climate forcing agent, both directly and indirectly, which is different to what generally concluded for crustal dust in the 2013 IPCC report. The high frequency, severity and year-round activity of volcanic dust emissions suggest that Icelandic dust may contribute to Arctic warming.

  4. Thermodynamics of Enzyme-Catalyzed Reactions Database

    Science.gov (United States)

    SRD 74 Thermodynamics of Enzyme-Catalyzed Reactions Database (Web, free access)   The Thermodynamics of Enzyme-Catalyzed Reactions Database contains thermodynamic data on enzyme-catalyzed reactions that have been recently published in the Journal of Physical and Chemical Reference Data (JPCRD). For each reaction the following information is provided: the reference for the data, the reaction studied, the name of the enzyme used and its Enzyme Commission number, the method of measurement, the data and an evaluation thereof.

  5. Curious Cases of the Enzymes.

    Science.gov (United States)

    Ulusu, Nuriye Nuray

    2015-07-01

    Life as we know it heavily relies on biological catalysis, in fact, in a very nonromantic version of it, life could be considered as a series of chemical reactions, regulated by the guarding principles of thermodynamics. In ancient times, a beating heart was a good sign of vitality, however, to me, it is actually the presence of active enzymes that counts… Though we do not usually pay attention, the history of enzymology is as old as humanity itself, and dates back to the ancient times. This paper is dedicated to these early moments of this remarkable science that touched our lives in the past and will make life a lot more efficient for humanity in the future. There was almost always a delicate, fundamentally essential relationship between mankind and the enzymes. Challenged by a very alien and hostile Nature full of predators, prehistoric men soon discovered the medicinal properties of the plants, through trial and error. In fact, they accidently discovered the enzyme inhibitors and thus, in crude terms, kindled a sparkling area of research. These plant-derivatives that acted as enzyme inhibitors helped prehistoric men in their pursuit of survival and protection from predators; in hunting and fishing… Later in history, while the underlying purposes of survival and increasing the quality of life stayed intact, the ways and means of enzymology experienced a massive transformation, as the 'trial and error' methodology of the ancients is now replaced with rational scientific theories.

  6. Enzymes with activity toward Xyloglucan

    NARCIS (Netherlands)

    Vincken, J.P.

    2003-01-01

    Xyloglucans are plant cell wall polysaccharides, which belong to the hemicellulose class. Here the structural variations of xyloglucans will be reviewed. Subsequently, the anchoring of xyloglucan in the plant cell wall will be discussed. Enzymes involved in degradation or modification of xyloglucan

  7. Cellulase enzyme: Homology modeling, binding site identification and molecular docking

    Science.gov (United States)

    Selvam, K.; Senbagam, D.; Selvankumar, T.; Sudhakar, C.; Kamala-Kannan, S.; Senthilkumar, B.; Govarthanan, M.

    2017-12-01

    Cellulase is an enzyme that degrades the linear polysaccharide like cellulose into glucose by breaking the β-1,4- glycosidic bonds. These enzymes are the third largest enzymes with a great potential towards the ethanol production and play a vital role in degrading the biomass. The production of ethanol depends upon the ability of the cellulose to utilize the wide range of substrates. In this study, the 3D structure of cellulase from Acinetobacter sp. was modeled by using Modeler 9v9 and validated by Ramachandran plot. The accuracy of the predicted 3D structure was checked using Ramachandran plot analysis showed that 81.1% in the favored region, compatibility of an atomic model (3D) with amino acid sequence (1D) for the model was observed as 78.21% and 49.395% for Verify 3D and ERRAT at SAVES server. As the binding efficacy with the substrate might suggests the choice of the substrate as carbon and nitrogen sources, the cellobiose, cellotetraose, cellotetriose and laminaribiose were employed in the docking studies. The docking of cellobiose, cellotetraose, cellotetriose and laminaribiose with cellulase exhibited the binding energy of -6.1523 kJ/mol, -7.8759 kJ/mol,-6.1590 kJ/mol and -6.7185 kJ/mol, respectively. These docking studies revealed that cellulase has the greater potential towards the cellotetraose as a substrate for the high yield of ethanol.

  8. Health Insurance Premium Increases for the 5 Largest School Districts in the United States, 2004–2008

    Science.gov (United States)

    Cantillo, John R.

    2010-01-01

    Background Local school districts are often one of the largest, if not the largest, employers in their respective communities. Like many large employers, school districts offer health insurance to their employees. There is a lack of information about the rate of health insurance premiums in US school districts relative to other employers. Objective To assess the change in the costs of healthcare insurance in the 5 largest public school districts in the United States, between 2004 and 2008, as representative of large public employers in the country. Methods Data for this study were drawn exclusively from a survey sent to the 5 largest public school districts in the United States. The survey requested responses on 3 data elements for each benefit plan offered from 2004 through 2008; these included enrollment, employee costs, and employer costs. Results The premium growth for the 5 largest school districts has slowed down and is consistent with other purchasers—Kaiser/Health Research & Educational Trust and the Federal Employee Health Benefit Program. The average increase in health insurance premium for the schools was 5.9% in 2008, and the average annual growth rate over the study period was 7.5%. For family coverage, these schools provide the most generous employer contribution (80.8%) compared with the employer contribution reported by other employers (73.5%) for 2008. Conclusions Often the largest employers in their communities, school districts demonstrate a commitment to provide choice of benefits and affordability for employees and their families. Despite constraints typical of public employers, the 5 largest school districts in the United States have decelerated in premium growth consistent with other purchasers, albeit at a slower pace. PMID:25126311

  9. Health insurance premium increases for the 5 largest school districts in the United States, 2004-2008.

    Science.gov (United States)

    Cantillo, John R

    2010-03-01

    Local school districts are often one of the largest, if not the largest, employers in their respective communities. Like many large employers, school districts offer health insurance to their employees. There is a lack of information about the rate of health insurance premiums in US school districts relative to other employers. To assess the change in the costs of healthcare insurance in the 5 largest public school districts in the United States, between 2004 and 2008, as representative of large public employers in the country. Data for this study were drawn exclusively from a survey sent to the 5 largest public school districts in the United States. The survey requested responses on 3 data elements for each benefit plan offered from 2004 through 2008; these included enrollment, employee costs, and employer costs. The premium growth for the 5 largest school districts has slowed down and is consistent with other purchasers-Kaiser/Health Research & Educational Trust and the Federal Employee Health Benefit Program. The average increase in health insurance premium for the schools was 5.9% in 2008, and the average annual growth rate over the study period was 7.5%. For family coverage, these schools provide the most generous employer contribution (80.8%) compared with the employer contribution reported by other employers (73.5%) for 2008. Often the largest employers in their communities, school districts demonstrate a commitment to provide choice of benefits and affordability for employees and their families. Despite constraints typical of public employers, the 5 largest school districts in the United States have decelerated in premium growth consistent with other purchasers, albeit at a slower pace.

  10. What caused the UK's largest common dolphin (Delphinus delphis mass stranding event?

    Directory of Open Access Journals (Sweden)

    Paul D Jepson

    Full Text Available On 9 June 2008, the UK's largest mass stranding event (MSE of short-beaked common dolphins (Delphinus delphis occurred in Falmouth Bay, Cornwall. At least 26 dolphins died, and a similar number was refloated/herded back to sea. On necropsy, all dolphins were in good nutritive status with empty stomachs and no evidence of known infectious disease or acute physical injury. Auditory tissues were grossly normal (26/26 but had microscopic haemorrhages (5/5 and mild otitis media (1/5 in the freshest cases. Five lactating adult dolphins, one immature male, and one immature female tested were free of harmful algal toxins and had low chemical pollutant levels. Pathological evidence of mud/seawater inhalation (11/26, local tide cycle, and the relative lack of renal myoglobinuria (26/26 suggested MSE onset on a rising tide between 06:30 and 08∶21 hrs (9 June. Potential causes excluded or considered highly unlikely included infectious disease, gas/fat embolism, boat strike, by-catch, predator attack, foraging unusually close to shore, chemical or algal toxin exposure, abnormal weather/climatic conditions, and high-intensity acoustic inputs from seismic airgun arrays or natural sources (e.g., earthquakes. International naval exercises did occur in close proximity to the MSE with the most intense part of the exercises (including mid-frequency sonars occurring four days before the MSE and resuming with helicopter exercises on the morning of the MSE. The MSE may therefore have been a "two-stage process" where a group of normally pelagic dolphins entered Falmouth Bay and, after 3-4 days in/around the Bay, a second acoustic/disturbance event occurred causing them to strand en masse. This spatial and temporal association with the MSE, previous associations between naval activities and cetacean MSEs, and an absence of other identifiable factors known to cause cetacean MSEs, indicates naval activity to be the most probable cause of the Falmouth Bay MSE.

  11. Transcriptome Sequencing and Analysis for Culm Elongation of the World's Largest Bamboo (Dendrocalamus sinicus.

    Directory of Open Access Journals (Sweden)

    Kai Cui

    Full Text Available Dendrocalamus sinicus is the world's largest bamboo species with strong woody culms, and known for its fast-growing culms. As an economic bamboo species, it was popularized for multi-functional applications including furniture, construction, and industrial paper pulp. To comprehensively elucidate the molecular processes involved in its culm elongation, Illumina paired-end sequencing was conducted. About 65.08 million high-quality reads were produced, and assembled into 81,744 unigenes with an average length of 723 bp. A total of 64,338 (79% unigenes were annotated for their functions, of which, 56,587 were annotated in the NCBI non-redundant protein database and 35,262 were annotated in the Swiss-Prot database. Also, 42,508 and 21,009 annotated unigenes were allocated to gene ontology (GO categories and clusters of orthologous groups (COG, respectively. By searching against the Kyoto Encyclopedia of Genes and Genomes Pathway database (KEGG, 33,920 unigenes were assigned to 128 KEGG pathways. Meanwhile, 8,553 simple sequence repeats (SSRs and 81,534 single-nucleotide polymorphism (SNPs were identified, respectively. Additionally, 388 transcripts encoding lignin biosynthesis were detected, among which, 27 transcripts encoding Shikimate O-hydroxycinnamoyltransferase (HCT specifically expressed in D. sinicus when compared to other bamboo species and rice. The phylogenetic relationship between D. sinicus and other plants was analyzed, suggesting functional diversity of HCT unigenes in D. sinicus. We conjectured that HCT might lead to the high lignin content and giant culm. Given that the leaves are not yet formed and culm is covered with sheaths during culm elongation, the existence of photosynthesis of bamboo culm is usually neglected. Surprisedly, 109 transcripts encoding photosynthesis were identified, including photosystem I and II, cytochrome b6/f complex, photosynthetic electron transport and F-type ATPase, and 24 transcripts were characterized

  12. Evaluation of world's largest social welfare scheme: An assessment using non-parametric approach.

    Science.gov (United States)

    Singh, Sanjeet

    2016-08-01

    Mahatma Gandhi National Rural Employment Guarantee Act (MGNREGA) is the world's largest social welfare scheme in India for the poverty alleviation through rural employment generation. This paper aims to evaluate and rank the performance of the states in India under MGNREGA scheme. A non-parametric approach, Data Envelopment Analysis (DEA) is used to calculate the overall technical, pure technical, and scale efficiencies of states in India. The sample data is drawn from the annual official reports published by the Ministry of Rural Development, Government of India. Based on three selected input parameters (expenditure indicators) and five output parameters (employment generation indicators), I apply both input and output oriented DEA models to estimate how well the states utilize their resources and generate outputs during the financial year 2013-14. The relative performance evaluation has been made under the assumption of constant returns and also under variable returns to scale to assess the impact of scale on performance. The results indicate that the main source of inefficiency is both technical and managerial practices adopted. 11 states are overall technically efficient and operate at the optimum scale whereas 18 states are pure technical or managerially efficient. It has been found that for some states it necessary to alter scheme size to perform at par with the best performing states. For inefficient states optimal input and output targets along with the resource savings and output gains are calculated. Analysis shows that if all inefficient states operate at optimal input and output levels, on an average 17.89% of total expenditure and a total amount of $780million could have been saved in a single year. Most of the inefficient states perform poorly when it comes to the participation of women and disadvantaged sections (SC&ST) in the scheme. In order to catch up with the performance of best performing states, inefficient states on an average need to enhance

  13. Distribution and Modeled Transport of Plastic Pollution in the Great Lakes, the World's Largest Freshwater Resource

    Directory of Open Access Journals (Sweden)

    Rachel N. Cable

    2017-07-01

    Full Text Available Most plastic pollution originates on land. As such, freshwater bodies serve as conduits for the transport of plastic litter to the ocean. Understanding the concentrations and fluxes of plastic litter in freshwater ecosystems is critical to our understanding of the global plastic litter budget and underpins the success of future management strategies. We conducted a replicated field survey of surface plastic concentrations in four lakes in the North American Great Lakes system, the largest contiguous freshwater system on the planet. We then modeled plastic transport to resolve spatial and temporal variability of plastic distribution in one of the Great Lakes, Lake Erie. Triplicate surface samples were collected at 38 stations in mid-summer of 2014. Plastic particles >106 μm in size were quantified. Concentrations were highest near populated urban areas and their water infrastructure. In the highest concentration trawl, nearly 2 million fragments km−2 were found in the Detroit River—dwarfing previous reports of Great Lakes plastic abundances by over 4-fold. Yet, the accuracy of single trawl counts was challenged: within-station plastic abundances varied 0- to 3-fold between replicate trawls. In the smallest size class (106–1,000 μm, false positive rates of 12–24% were determined analytically for plastic vs. non-plastic, while false negative rates averaged ~18%. Though predicted to form in summer by the existing Lake Erie circulation model, our transport model did not predict a permanent surface “Lake Erie Garbage Patch” in its central basin—a trend supported by field survey data. Rather, general eastward transport with recirculation in the major basins was predicted. Further, modeled plastic residence times were drastically influenced by plastic buoyancy. Neutrally buoyant plastics—those with the same density as the ambient water—were flushed several times slower than plastics floating at the water's surface and exceeded the

  14. Africa's largest long-lasting insecticide-treated net producer: lessons from A to Z Textiles.

    Science.gov (United States)

    Masum, Hassan; Shah, Ronak; Schroeder, Karl; Daar, Abdallah S; Singer, Peter A

    2010-12-13

    Field trials have demonstrated the efficacy of insecticide-treated nets, and the WHO has recently endorsed a shift toward Long-Lasting Insecticide Treated nets (LLINs) due to factors such as reduced distribution costs. However, the need for LLINs poses several challenges. Is it possible to manufacture LLINs in large quantities in the African continent, where malaria is most endemic? When production is located in low-income countries, what role is played by local funding and employment, scaling up manufacturing, and partnerships? What factors influence availability and pricing? A case study of A to Z Textiles was undertaken to answer the question of how large-scale production of LLINs can occur in a low income setting. One of the largest sources of bed nets for Africa, A to Z Textiles is Africa-based, and its Tanzanian operations have a production capacity of 30 million LLINs per year, along with full WHO recommendation for its nets. Our analysis is based on semi-structured interviews with key informants familiar with A to Z, site visits in Tanzania, and literature reviews.This paper discusses the history and current status of A to Z Textiles, identifies the factors that led to its success, and suggests policy considerations that could support similar initiatives in the future. Local funding, scaling up manufacturing, technology transfer, and partnerships all played important roles in A to Z's ascent, as did perceived benefits of local employment and capacity-building. Regulatory issues and procurement rules acted as barriers. A to Z cost-effectively manufactures high-quality LLINs where malaria is most endemic. With a production capacity of 30 million LLINs per year, and full WHOPES (WHO Pesticide Evaluation Scheme) certification, A to Z Textiles demonstrates how key health goods can be successfully produced in the low-income countries that use them. Its example may be instructive and of high interest to readers in the malaria community, especially in developing

  15. Helicobacter pylori virulence genes in the five largest islands of Indonesia.

    Science.gov (United States)

    Miftahussurur, Muhammad; Syam, Ari Fahrial; Makmun, Dadang; Nusi, Iswan Abbas; Zein, Lukman Hakim; Zulkhairi; Akil, Fardah; Uswan, Willi Brodus; Simanjuntak, David; Uchida, Tomohisa; Adi, Pangestu; Utari, Amanda Pitarini; Rezkitha, Yudith Annisa Ayu; Subsomwong, Phawinee; Nasronudin; Yamaoka, Yoshio

    2015-01-01

    It remains unclear whether the low incidence of gastric cancer in Indonesia is due to low infection rates only or is also related to low Helicobacter pylori pathogenicity. We collected H. pylori strains from the five largest islands in Indonesia and evaluated genetic virulence factors. The genotypes of H. pylori virulence factors were determined by polymerase chain reaction (PCR)-based sequencing. Histological severity of the gastric mucosa was classified into 4 grades, according to the updated Sydney system. A total of 44 strains were analyzed. Forty-three (97.7 %) were cagA-positive: 26 (60.5 %) were East-Asian-type-cagA, 9 (20.9 %) were Western-type-cagA, and 8 (18.6 %) were novel ABB-type, most of which were obtained from Papuan. EPIYT sequences were more prevalent than EPIYA sequences (P = 0.01) in the EPIYA-B motif of all types of cagA. The majority of cagA-positive strains (48.8 %, 21/43) had a 6-bp deletion in the first pre-EPIYA region. Subjects infected with East-Asian-type-cagA strains with a 6-bp deletion had significantly lower inflammation and atrophy scores in the corpus than those infected with Western-type-cagA strains (both P = 0.02). In total, 70.4 % of strains possessed the vacA s1m1 genotype and 29.5 % were m2. All strains from peptic ulcer patients were of the iceA1 genotype, which occurred at a significantly higher proportion in peptic ulcer patients than that in gastritis patients (55.3 %, P = 0.04). The double positive genotype of jhp0562/β-(1,3)galT was predominant (28/44, 63.6 %), and subjects infected with this type had significantly higher inflammation scores in the corpus than those with the jhp0562 negative/β-(1,3)galT positive genotype (mean [median]; 1.43 [1] vs. 0.83 [1], P = 0.04). There were significant differences in cagA and pre-EPIYA cagA type, oipA status, and jhp0562/β-(1,3)galT type among different ethnic groups (P dupA negative or short type dupA, and the jhp0562/β-(1,3)galT double positive genotype.

  16. Oak habitat recovery on California's largest islands: Scenarios for the role of corvid seed dispersal

    Science.gov (United States)

    Pesendorfer, Mario B.; Baker, Christopher M.; Stringer, Martin; McDonald-Madden, Eve; Bode, Michael; McEachern, A. Kathryn; Morrison, Scott A.; Sillett, T. Scott

    2018-01-01

    California's second-largest island. The simulation model, extensively parameterized with field data, suggests that re-establishing the mutualism with seed-hoarding jays would accelerate the expansion of island scrub oak, which could benefit myriad species of conservation concern.

  17. What Caused the UK's Largest Common Dolphin (Delphinus delphis) Mass Stranding Event?

    Science.gov (United States)

    Jepson, Paul D.; Deaville, Robert; Acevedo-Whitehouse, Karina; Barnett, James; Brownlow, Andrew; Brownell Jr., Robert L.; Clare, Frances C.; Davison, Nick; Law, Robin J.; Loveridge, Jan; Macgregor, Shaheed K.; Morris, Steven; Murphy, Sinéad; Penrose, Rod; Perkins, Matthew W.; Pinn, Eunice; Seibel, Henrike; Siebert, Ursula; Sierra, Eva; Simpson, Victor; Tasker, Mark L.; Tregenza, Nick; Cunningham, Andrew A.; Fernández, Antonio

    2013-01-01

    On 9 June 2008, the UK's largest mass stranding event (MSE) of short-beaked common dolphins (Delphinus delphis) occurred in Falmouth Bay, Cornwall. At least 26 dolphins died, and a similar number was refloated/herded back to sea. On necropsy, all dolphins were in good nutritive status with empty stomachs and no evidence of known infectious disease or acute physical injury. Auditory tissues were grossly normal (26/26) but had microscopic haemorrhages (5/5) and mild otitis media (1/5) in the freshest cases. Five lactating adult dolphins, one immature male, and one immature female tested were free of harmful algal toxins and had low chemical pollutant levels. Pathological evidence of mud/seawater inhalation (11/26), local tide cycle, and the relative lack of renal myoglobinuria (26/26) suggested MSE onset on a rising tide between 06∶30 and 08∶21 hrs (9 June). Potential causes excluded or considered highly unlikely included infectious disease, gas/fat embolism, boat strike, by-catch, predator attack, foraging unusually close to shore, chemical or algal toxin exposure, abnormal weather/climatic conditions, and high-intensity acoustic inputs from seismic airgun arrays or natural sources (e.g., earthquakes). International naval exercises did occur in close proximity to the MSE with the most intense part of the exercises (including mid-frequency sonars) occurring four days before the MSE and resuming with helicopter exercises on the morning of the MSE. The MSE may therefore have been a “two-stage process” where a group of normally pelagic dolphins entered Falmouth Bay and, after 3–4 days in/around the Bay, a second acoustic/disturbance event occurred causing them to strand en masse. This spatial and temporal association with the MSE, previous associations between naval activities and cetacean MSEs, and an absence of other identifiable factors known to cause cetacean MSEs, indicates naval activity to be the most probable cause of the Falmouth Bay MSE. PMID

  18. Transcriptome Sequencing and Analysis for Culm Elongation of the World's Largest Bamboo (Dendrocalamus sinicus).

    Science.gov (United States)

    Cui, Kai; Wang, Haiying; Liao, Shengxi; Tang, Qi; Li, Li; Cui, Yongzhong; He, Yuan

    2016-01-01

    Dendrocalamus sinicus is the world's largest bamboo species with strong woody culms, and known for its fast-growing culms. As an economic bamboo species, it was popularized for multi-functional applications including furniture, construction, and industrial paper pulp. To comprehensively elucidate the molecular processes involved in its culm elongation, Illumina paired-end sequencing was conducted. About 65.08 million high-quality reads were produced, and assembled into 81,744 unigenes with an average length of 723 bp. A total of 64,338 (79%) unigenes were annotated for their functions, of which, 56,587 were annotated in the NCBI non-redundant protein database and 35,262 were annotated in the Swiss-Prot database. Also, 42,508 and 21,009 annotated unigenes were allocated to gene ontology (GO) categories and clusters of orthologous groups (COG), respectively. By searching against the Kyoto Encyclopedia of Genes and Genomes Pathway database (KEGG), 33,920 unigenes were assigned to 128 KEGG pathways. Meanwhile, 8,553 simple sequence repeats (SSRs) and 81,534 single-nucleotide polymorphism (SNPs) were identified, respectively. Additionally, 388 transcripts encoding lignin biosynthesis were detected, among which, 27 transcripts encoding Shikimate O-hydroxycinnamoyltransferase (HCT) specifically expressed in D. sinicus when compared to other bamboo species and rice. The phylogenetic relationship between D. sinicus and other plants was analyzed, suggesting functional diversity of HCT unigenes in D. sinicus. We conjectured that HCT might lead to the high lignin content and giant culm. Given that the leaves are not yet formed and culm is covered with sheaths during culm elongation, the existence of photosynthesis of bamboo culm is usually neglected. Surprisedly, 109 transcripts encoding photosynthesis were identified, including photosystem I and II, cytochrome b6/f complex, photosynthetic electron transport and F-type ATPase, and 24 transcripts were characterized as antenna

  19. Africa's largest long-lasting insecticide-treated net producer: lessons from A to Z Textiles

    Directory of Open Access Journals (Sweden)

    Daar Abdallah S

    2010-12-01

    Full Text Available Abstract Background Field trials have demonstrated the efficacy of insecticide-treated nets, and the WHO has recently endorsed a shift toward Long-Lasting Insecticide Treated nets (LLINs due to factors such as reduced distribution costs. However, the need for LLINs poses several challenges. Is it possible to manufacture LLINs in large quantities in the African continent, where malaria is most endemic? When production is located in low-income countries, what role is played by local funding and employment, scaling up manufacturing, and partnerships? What factors influence availability and pricing? Discussion A case study of A to Z Textiles was undertaken to answer the question of how large-scale production of LLINs can occur in a low income setting. One of the largest sources of bed nets for Africa, A to Z Textiles is Africa-based, and its Tanzanian operations have a production capacity of 30 million LLINs per year, along with full WHO recommendation for its nets. Our analysis is based on semi-structured interviews with key informants familiar with A to Z, site visits in Tanzania, and literature reviews. This paper discusses the history and current status of A to Z Textiles, identifies the factors that led to its success, and suggests policy considerations that could support similar initiatives in the future. Local funding, scaling up manufacturing, technology transfer, and partnerships all played important roles in A to Z’s ascent, as did perceived benefits of local employment and capacity-building. Regulatory issues and procurement rules acted as barriers. A to Z cost-effectively manufactures high-quality LLINs where malaria is most endemic. Summary With a production capacity of 30 million LLINs per year, and full WHOPES (WHO Pesticide Evaluation Scheme certification, A to Z Textiles demonstrates how key health goods can be successfully produced in the low-income countries that use them. Its example may be instructive and of high interest to

  20. 7 CFR 58.436 - Rennet, pepsin, other milk clotting enzymes and flavor enzymes.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Rennet, pepsin, other milk clotting enzymes and flavor enzymes. 58.436 Section 58.436 Agriculture Regulations of the Department of Agriculture (Continued... clotting enzymes and flavor enzymes. Enzyme preparations used in the manufacture of cheese shall be safe...

  1. Heavy enzymes--experimental and computational insights in enzyme dynamics.

    Science.gov (United States)

    Swiderek, Katarzyna; Ruiz-Pernía, J Javier; Moliner, Vicent; Tuñón, Iñaki

    2014-08-01

    The role of protein motions in the chemical step of enzyme-catalyzed reactions is the subject of an open debate in the scientific literature. The systematic use of isotopically substituted enzymes has been revealed as a useful tool to quantify the role of these motions. According to the Born-Oppenheimer approximation, changing the mass of the protein does not change the forces acting on the system but alters the frequencies of the protein motions, which in turn can affect the rate constant. Experimental and theoretical studies carried out in this field are presented in this article and discussed in the framework of Transition State Theory. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Monomeric, dimeric and multimeric system of RGD peptides radiolabeled with {sup 177}Lu for tumors therapy that expressing αβ integrin s; Sistema monomerico, dimerico y multimerico de peptidos de RGD radiomarcados con {sup 177}Lu para terapia de tumores que expresan integrinas αβ

    Energy Technology Data Exchange (ETDEWEB)

    Luna G, M. A.

    2014-07-01

    The conjugation of peptides to gold nanoparticles (AuNPs) produces biocompatible and stable multimeric systems with target-specific molecular recognition. Peptides based on the cyclic Arg-Gly-Asp (RGD) sequence have been reported as high affinity agents for the α(v)β(3) and α(v)β(5) integrin. The aim of this research was to prepare a multimeric system of {sup 177}Lu-labeled gold nanoparticles conjugated to c[RGDfK(C)] [cyclo(Arg-Gly-Asp-Phe-Lys(Cys)] peptides and to compare the radiation absorbed dose with that of {sup 177}Lu-labeled monomeric and dimeric RGD peptides to α(v)β(3) integrin-positive U87MG tumors in mice, as well as, evaluate the in vitro potential {sup 177}Lu-AuNP-c[RGDfK(C)] as a plasmonic photothermal therapy and targeted radiotherapy system in MCF7 breast cancer cells. DOTA-GGC (1,4,7,10-tetraaza cyclododecane-N,N,N-tetraacetic-Gly-Gly-Cys) and c[RGDfK(C)] peptides were synthesized and conjugated to AuNPs by the spontaneous reaction of the thiol groups. Tem, UV-Vis, XP S, Raman and Far-IR spectroscopy techniques demonstrated that AuNPs were functionalized with the peptides. To obtain {sup 177}Lu-AuNP-c[RGDfK(C)], the {sup 177}Lu-DOTA-GGC radio peptide was first prepared and added to a solution of AuNPs followed by c[RGDfK(C)] (25 μL, 5 μM) at 18 grades C for 15 min. {sup 177}Lu-DOTA-GGC, {sup 177}Lu- DOTA-cRGDfK and {sup 177}Lu-DOTA-E-c(RGDfK){sub 2} were prepared by adding {sup 177}LuCl{sub 3} (370 MBq) to 5 μL (1 mg/ml) of the DOTA derivative diluted with 50 μL of 1 M acetate buffer at ph 5. The mixture was incubated at 90 grades C in a block heater for 30 min. Radiochemical purity was determined by ultrafiltration and HPLC analyses. After laser irradiation, the presence of c[RGDfK(C)]-AuNP in cells caused a significant increase in the temperature of the medium (50.5 grades C, compared to 40.3 grades C without AuNPs) resulting in a significant decrease in MCF7 cell viability down to 9 %. After treatment with {sup 177}Lu

  3. Enzyme technology: Key to selective biorefining

    DEFF Research Database (Denmark)

    Meyer, Anne S.

    2014-01-01

    to the reaction is a unique trait of enzyme catalysis. Since enzyme selectivity means that a specific reaction is catalysed between particular species to produce definite products, enzymes are particularly fit for converting specific compounds in mixed biomass streams. Since enzymes are protein molecules...... their rational use in biorefinery processes requires an understanding of the basic features of enzymes and reaction traits with respect to specificity, kinetics, reaction optima, stability and structure-function relations – we are now at a stage where it is possible to use nature’s enzyme structures as starting...... point and then improve the functional traits by targeted mutation of the protein. The talk will display some of our recent hypotheses related to enzyme action, recently obtained results within knowledge-based enzyme improvements as well as cast light on research methods used in optimizing enzyme...

  4. Study of DNA reconstruction enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Sekiguchi, M [Kyushu Univ., Fukuoka (Japan). Faculty of Science

    1976-12-01

    Description was made of the characteristics and mechanism of 3 reconstructive enzymes which received from M. luteus or E. coli or T4, and of which natures were clarified as reconstructive enzymes of DNA irradiated with ultraviolet rays. As characteristics, the site of breaking, reaction, molecular weight, electric charge in the neutrality and a specific adhesion to DNA irradiated with ultraviolet rays were mentioned. As to mutant of ultraviolet ray sensitivity, hereditary control mechanism of removal and reconstruction by endo-nuclease activation was described, and suggestion was referred to removal and reconstruction of cells of xedoderma pigmentosum which is a hereditary disease of human. Description was also made as to the mechanism of exonuclease activation which separates dimer selectively from irradiated DNA.

  5. Metrological aspects of enzyme production

    International Nuclear Information System (INIS)

    Kerber, T M; Pereira-Meirelles, F V; Dellamora-Ortiz, G M

    2010-01-01

    Enzymes are frequently used in biotechnology to carry out specific biological reactions, either in industrial processes or for the production of bioproducts and drugs. Microbial lipases are an important group of biotechnologically valuable enzymes that present widely diversified applications. Lipase production by microorganisms is described in several published papers; however, none of them refer to metrological evaluation and the estimation of the uncertainty in measurement. Moreover, few of them refer to process optimization through experimental design. The objectives of this work were to enhance lipase production in shaken-flasks with Yarrowia lipolytica cells employing experimental design and to evaluate the uncertainty in measurement of lipase activity. The highest lipolytic activity obtained was about three- and fivefold higher than the reported activities of CRMs BCR-693 and BCR-694, respectively. Lipase production by Y. lipolytica cells aiming the classification as certified reference material is recommended after further purification and stability studies

  6. Lessons from the Largest Epidemic of Avian Influenza Viruses in Taiwan, 2015.

    Science.gov (United States)

    Chang, Ching-Fen; King, Chwan-Chuen; Wan, Cho-Hua; Chang, Yun-Cheng; Chan, Ta-Chien; David Lee, Chang-Chun; Chou, Po-Hao Borris; Li, Zheng-Rong Tiger; Li, Yao-Tsun; Tseng, Tzu-Jung; Lee, Pei-Fen; Chang, Chuan-Hsiung

    2016-05-01

    The largest epidemic of avian influenza (AI) in history attacked poultry and wild birds throughout Taiwan starting January 6, 2015. This study analyzed surveillance results, epidemiologic characteristics, and viral sequences by using government-released information, with the intention to provide recommendations to minimize future pandemic influenza. The H5 clade 2.3.4.4 highly pathogenic AI viruses (HPAIVs) had not been detected in Taiwan before 2015. During this epidemic, four types of etiologic agents were identified: the three novel subtypes H5N2, H5N8, and H5N3 clade 2.3.4.4 HPAIVs and one endemic chicken H5N2 subtype (Mexican-like lineage) of low pathogenic AI viruses. Cocirculation of mixed subtypes also occurred, with H5N2 clade 2.3.4.4 HPAIVs accompanied by the H5N8 and H5N3 subtypes or old H5N2 viruses in the same farm. More than 90% of domestic geese died from this AI epidemic; geese were affected the most at the early outbreaks. The epidemic peaked in mid-January for all three novel H5 subtypes. Spatial epidemiology found that most affected areas were located in southwestern coastal areas. In terrestrial poultry (mostly chickens), different geographic distributions of AI virus subtypes were detected, with hot spots of H5N2 clade 2.3.4.4 vs. past-endemic old H5N2 viruses in Changhwa (P = 0.03) and Yunlin (P = 0.007) counties, respectively, of central Taiwan. Phylogenetic and sequence analyses of all the early 10 Taiwan H5 clade 2.3.4.4 isolates covering the three subtypes showed that they were very different from the HA of the past local H5 viruses from domestic ducks (75%-80%) and chickens (70%-75%). However, they had the highest sequence identity percentages (99.53%-100%), with the HA of A/crane/Kagoshima/KU13/2014(H5N8) isolated on December 7, 2014, in Japan being higher than those of recent American and Korean H5 HPAIVs [A/Northern pintail/Washington/40964/2014 (H5N2) and A/gyrfalcon/Washington/41088-6/2014 (H5N8): 99.02%-99.54% and A/Baikal teal

  7. Consumer attitudes to enzymes in food production

    DEFF Research Database (Denmark)

    Søndergaard, Helle Alsted; Grunert, Klaus G.; Scholderer, Joachim

    2005-01-01

    The use of enzymes in food production has potential benefits for both food manufacturers and consumers. A central question is how consumers react to new ways of producing foods with enzymes. This study investigates the formation of consumer attitudes to different enzyme production methods in three...... European countries. Results show that consumers are most positive towards non-GM enzyme production methods. The enzyme production method is by far the most important factor for the formation of buying intentions compared to price and benefits. Results also show that environmental concern and attitudes...... to technological progress are the socio-political attitudes that have the highest predictive value regarding attitudes to enzyme production methods....

  8. Research progress of nanoparticles as enzyme mimetics

    Science.gov (United States)

    Hu, XiaoNa; Liu, JianBo; Hou, Shuai; Wen, Tao; Liu, WenQi; Zhang, Ke; He, WeiWei; Ji, YingLu; Ren, HongXuan; Wang, Qi; Wu, XiaoChun

    2011-10-01

    Natural enzymes as biological catalysts possess remarkable advantages, especially their highly efficient and selective catalysis under mild conditions. However, most natural enzymes are proteins, thus exhibiting an inherent low durability to harsh reaction conditions. Artificial enzyme mimetics have been pursued extensively to avoid this drawback. Quite recently, some inorganic nanoparticles (NPs) have been found to exhibit unique enzyme mimetics. In addition, their much higher stability overcomes the inherent disadvantage of natural enzymes. Furthermore, easy mass-production and low cost endow them more benefits. As a new member of artificial enzyme mimetics, they have received intense attention. In this review article, major progress in this field is summarized and future perspectives are highlighted.

  9. Allosteric regulation of epigenetic modifying enzymes.

    Science.gov (United States)

    Zucconi, Beth E; Cole, Philip A

    2017-08-01

    Epigenetic enzymes including histone modifying enzymes are key regulators of gene expression in normal and disease processes. Many drug development strategies to target histone modifying enzymes have focused on ligands that bind to enzyme active sites, but allosteric pockets offer potentially attractive opportunities for therapeutic development. Recent biochemical studies have revealed roles for small molecule and peptide ligands binding outside of the active sites in modulating the catalytic activities of histone modifying enzymes. Here we highlight several examples of allosteric regulation of epigenetic enzymes and discuss the biological significance of these findings. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Astronomers Break Ground on Atacama Large Millimeter Array (ALMA) - World's Largest Millimeter Wavelength Telescope

    Science.gov (United States)

    2003-11-01

    Scientists and dignitaries from Europe, North America and Chile are breaking ground today (Thursday, November 6, 2003) on what will be the world's largest, most sensitive radio telescope operating at millimeter wavelengths . ALMA - the "Atacama Large Millimeter Array" - will be a single instrument composed of 64 high-precision antennas located in the II Region of Chile, in the District of San Pedro de Atacama, at the Chajnantor altiplano, 5,000 metres above sea level. ALMA 's primary function will be to observe and image with unprecedented clarity the enigmatic cold regions of the Universe, which are optically dark, yet shine brightly in the millimetre portion of the electromagnetic spectrum. The Atacama Large Millimeter Array (ALMA) is an international astronomy facility. ALMA is an equal partnership between Europe and North America, in cooperation with the Republic of Chile, and is funded in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC), and in Europe by the European Southern Observatory (ESO) and Spain. ALMA construction and operations are led on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI), and on behalf of Europe by ESO. " ALMA will be a giant leap forward for our studies of this relatively little explored spectral window towards the Universe" , said Dr. Catherine Cesarsky , Director General of ESO. "With ESO leading the European part of this ambitious and forward-looking project, the impact of ALMA will be felt in wide circles on our continent. Together with our partners in North America and Chile, we are all looking forward to the truly outstanding opportunities that will be offered by ALMA , also to young scientists and engineers" . " The U.S. National Science Foundation joins today with our North American partner, Canada, and with the European Southern Observatory, Spain, and Chile to prepare

  11. Silica-Immobilized Enzyme Reactors

    Science.gov (United States)

    2007-08-01

    Silica-IMERs 14 implicated in neurological disorders such as Schizophrenia and Parkinson’s disease.[86] Drug discovery for targets that can alter the...primarily the activation of prodrugs and proantibiotics for cancer treatments or antibiotic therapy , respectively.[87] Nitrobenzene nitroreductase was...BuChE) Monolith disks* Packed Silica Biosilica Epoxide- Silica Silica-gel Enzyme Human AChE Human AChE Human AChE Equine BuChE Human

  12. Immobilised enzymes in biorenewable production

    OpenAIRE

    Franssen, M.C.R.; Steunenberg, P.; Scott, E.L.; Zuilhof, H.; Sanders, J.P.M.

    2013-01-01

    Oils, fats, carbohydrates, lignin, and amino acids are all important raw materials for the production of biorenewables. These compounds already play an important role in everyday life in the form of wood, fabrics, starch, paper and rubber. Enzymatic reactions do, in principle, allow the transformation of these raw materials into biorenewables under mild and sustainable conditions. There are a few examples of processes using immobilised enzymes that are already applied on an industrial scale, ...

  13. Immobilization of enzymes by radiation

    International Nuclear Information System (INIS)

    Kaetsu, I.; Kumakura, M.; Yoshida, M.; Asano, M.; Himei, M.; Tamura, M.; Hayashi, K.

    1979-01-01

    Immobilization of various enzymes was performed by radiation-induced polymerization of glass-forming monomers at low temperatures. Alpha-amylase and glucoamylase were effectively immobilized in hydrophilic polymer carrier such as poly(2-hydroxyethyl methacrylate) and also in rather hydrophobic carrier such as poly(tetraethylene-glycol diacrylate). Immobilized human hemoglobin underwent the reversible oxygenation concomitantly with change of oxygen concentration outside of the matrices. (author)

  14. Lignin-degrading enzyme activities.

    Science.gov (United States)

    Chen, Yi-ru; Sarkanen, Simo; Wang, Yun-Yan

    2012-01-01

    Over the past three decades, the activities of four kinds of enzyme have been purported to furnish the mechanistic foundations for macromolecular lignin depolymerization in decaying plant cell walls. The pertinent fungal enzymes comprise lignin peroxidase (with a relatively high redox potential), manganese peroxidase, an alkyl aryl etherase, and laccase. The peroxidases and laccase, but not the etherase, are expressed extracellularly by white-rot fungi. A number of these microorganisms exhibit a marked preference toward lignin in their degradation of lignocellulose. Interestingly, some white-rot fungi secrete both kinds of peroxidase but no laccase, while others that are equally effective express extracellular laccase activity but no peroxidases. Actually, none of these enzymes has been reported to possess significant depolymerase activity toward macromolecular lignin substrates that are derived with little chemical modification from the native biopolymer. Here, the assays commonly employed for monitoring the traditional fungal peroxidases, alkyl aryl etherase, and laccase are described in their respective contexts. A soluble native polymeric substrate that can be isolated directly from a conventional milled-wood lignin preparation is characterized in relation to its utility in next-generation lignin-depolymerase assays.

  15. Immobilised enzymes in biorenewables production.

    Science.gov (United States)

    Franssen, Maurice C R; Steunenberg, Peter; Scott, Elinor L; Zuilhof, Han; Sanders, Johan P M

    2013-08-07

    Oils, fats, carbohydrates, lignin, and amino acids are all important raw materials for the production of biorenewables. These compounds already play an important role in everyday life in the form of wood, fabrics, starch, paper and rubber. Enzymatic reactions do, in principle, allow the transformation of these raw materials into biorenewables under mild and sustainable conditions. There are a few examples of processes using immobilised enzymes that are already applied on an industrial scale, such as the production of High-Fructose Corn Syrup, but these are still rather rare. Fortunately, there is a rapid expansion in the research efforts that try to improve this, driven by a combination of economic and ecological reasons. This review focusses on those efforts, by looking at attempts to use fatty acids, carbohydrates, proteins and lignin (and their building blocks), as substrates in the synthesis of biorenewables using immobilised enzymes. Therefore, many examples (390 references) from the recent literature are discussed, in which we look both at the specific reactions as well as to the methods of immobilisation of the enzymes, as the latter are shown to be a crucial factor with respect to stability and reuse. The applications of the renewables produced in this way range from building blocks for the pharmaceutical and polymer industry, transport fuels, to additives for the food industry. A critical evaluation of the relevant factors that need to be improved for large-scale use of these examples is presented in the outlook of this review.

  16. Self-powered enzyme micropumps

    Science.gov (United States)

    Sengupta, Samudra; Patra, Debabrata; Ortiz-Rivera, Isamar; Agrawal, Arjun; Shklyaev, Sergey; Dey, Krishna K.; Córdova-Figueroa, Ubaldo; Mallouk, Thomas E.; Sen, Ayusman

    2014-05-01

    Non-mechanical nano- and microscale pumps that function without the aid of an external power source and provide precise control over the flow rate in response to specific signals are needed for the development of new autonomous nano- and microscale systems. Here we show that surface-immobilized enzymes that are independent of adenosine triphosphate function as self-powered micropumps in the presence of their respective substrates. In the four cases studied (catalase, lipase, urease and glucose oxidase), the flow is driven by a gradient in fluid density generated by the enzymatic reaction. The pumping velocity increases with increasing substrate concentration and reaction rate. These rechargeable pumps can be triggered by the presence of specific analytes, which enables the design of enzyme-based devices that act both as sensor and pump. Finally, we show proof-of-concept enzyme-powered devices that autonomously deliver small molecules and proteins in response to specific chemical stimuli, including the release of insulin in response to glucose.

  17. Substrate mediated enzyme prodrug therapy.

    Directory of Open Access Journals (Sweden)

    Betina Fejerskov

    Full Text Available In this report, we detail Substrate Mediated Enzyme Prodrug Therapy (SMEPT as a novel approach in drug delivery which relies on enzyme-functionalized cell culture substrates to achieve a localized conversion of benign prodrug(s into active therapeutics with subsequent delivery to adhering cells or adjacent tissues. For proof-of-concept SMEPT, we use surface adhered micro-structured physical hydrogels based on poly(vinyl alcohol, β-glucuronidase enzyme and glucuronide prodrugs. We demonstrate enzymatic activity mediated by the assembled hydrogel samples and illustrate arms of control over rate of release of model fluorescent cargo. SMEPT was not impaired by adhering cells and afforded facile time - and dose - dependent uptake of the in situ generated fluorescent cargo by hepatic cells, HepG2. With the use of a glucuronide derivative of an anticancer drug, SN-38, SMEPT afforded a decrease in cell viability to a level similar to that achieved using parent drug. Finally, dose response was achieved using SMEPT and administration of judiciously chosen concentration of SN-38 glucuronide prodrug thus revealing external control over drug delivery using drug eluting surface. We believe that this highly adaptable concept will find use in diverse biomedical applications, specifically surface mediated drug delivery and tissue engineering.

  18. Electro-ultrafiltration of industrial enzyme solutions

    DEFF Research Database (Denmark)

    Enevoldsen, Ann Dorrit; Hansen, Erik Børresen; Jonsson, Gunnar Eigil

    2007-01-01

    To reduce the problems with fouling and concentration polarization during crossflow ultrafiltration of industrial enzyme solutions an electric field is applied across the membrane. The filtration performance during electro-ultrafiltration (EUF) has been tested with several enzymes. Results show...

  19. Biochemical characterization of thermostable cellulase enzyme from ...

    African Journals Online (AJOL)

    user

    2012-05-29

    May 29, 2012 ... tested for their ability to produce cellulase complex enzyme by growing on a defined substrates as well ... In the current industrial processes, cellulolytic enzymes ... energy sources such as glucose, ethanol, hydrogen and.

  20. Epigenetics of dominance for enzyme activity

    Indian Academy of Sciences (India)

    Unknown

    dimer over a wide range of H+ concentrations accounts for the epigenetics of dominance for enzyme activity. [Trehan K S ... The present study has been carried on acid phosphatase .... enzyme activity over mid parent value (table 3, col. 13),.

  1. Castor Oil Transesterification Catalysed by Liquid Enzymes

    DEFF Research Database (Denmark)

    Andrade, Thalles; Errico, Massimiliano; Christensen, Knud Villy

    2017-01-01

    In the present work, biodiesel production by reaction of non-edible castor oil with methanol under enzymatic catalysis is investigated. Two liquid enzymes were tested: Eversa Transform and Resinase HT. Reactions were performed at 35 °C and with a molar ratio of methanol to oil of 6:1. The reaction...... time was 8 hours. Stepwise addition of methanol was necessary to avoid enzyme inhibition by methanol. In order to minimize the enzyme costs, the influence of enzyme activity loss during reuse of both enzymes was evaluated under two distinct conditions. In the former, the enzymes were recovered...... and fully reused; in the latter, a mixture of 50 % reused and 50 % fresh enzymes was tested. In the case of total reuse after three cycles, both enzymes achieved only low conversions. The biodiesel content in the oil-phase using Eversa Transform was 94.21 % for the first cycle, 68.39 % in the second, and 33...

  2. ESO Signs Largest-Ever European Industrial Contract For Ground-Based Astronomy Project ALMA

    Science.gov (United States)

    2005-12-01

    ESO, the European Organisation for Astronomical Research in the Southern Hemisphere, announced today that it has signed a contract with the consortium led by Alcatel Alenia Space and composed also of European Industrial Engineering (Italy) and MT Aerospace (Germany), to supply 25 antennas for the Atacama Large Millimeter Array (ALMA) project, along with an option for another seven antennas. The contract, worth 147 million euros, covers the design, manufacture, transport and on-site integration of the antennas. It is the largest contract ever signed in ground-based astronomy in Europe. The ALMA antennas present difficult technical challenges, since the antenna surface accuracy must be within 25 microns, the pointing accuracy within 0.6 arc seconds, and the antennas must be able to be moved between various stations on the ALMA site. This is especially remarkable since the antennas will be located outdoor in all weather conditions, without any protection. Moreover, the ALMA antennas can be pointed directly at the Sun. ALMA will have a collecting area of more than 5,600 square meters, allowing for unprecedented measurements of extremely faint objects. The signing ceremony took place on December 6, 2005 at ESO Headquarters in Garching, Germany. "This contract represents a major milestone. It allows us to move forward, together with our American and Japanese colleagues, in this very ambitious and unique project," said ESO's Director General, Dr. Catherine Cesarsky. "By building ALMA, we are giving European astronomers access to the world's leading submillimetre facility at the beginning of the next decade, thereby fulfilling Europe's desire to play a major role in this field of fundamental research." Pascale Sourisse, Chairman and CEO of Alcatel Alenia Space, said: "We would like to thank ESO for trusting us to take on this new challenge. We are bringing to the table not only our recognized expertise in antenna development, but also our long-standing experience in

  3. Deep, diverse and definitely different: unique attributes of the world's largest ecosystem

    Directory of Open Access Journals (Sweden)

    E. Ramirez-Llodra

    2010-09-01

    Full Text Available The deep sea, the largest biome on Earth, has a series of characteristics that make this environment both distinct from other marine and land ecosystems and unique for the entire planet. This review describes these patterns and processes, from geological settings to biological processes, biodiversity and biogeographical patterns. It concludes with a brief discussion of current threats from anthropogenic activities to deep-sea habitats and their fauna.

    Investigations of deep-sea habitats and their fauna began in the late 19th century. In the intervening years, technological developments and stimulating discoveries have promoted deep-sea research and changed our way of understanding life on the planet. Nevertheless, the deep sea is still mostly unknown and current discovery rates of both habitats and species remain high. The geological, physical and geochemical settings of the deep-sea floor and the water column form a series of different habitats with unique characteristics that support specific faunal communities. Since 1840, 28 new habitats/ecosystems have been discovered from the shelf break to the deep trenches and discoveries of new habitats are still happening in the early 21st century. However, for most of these habitats the global area covered is unknown or has been only very roughly estimated; an even smaller – indeed, minimal – proportion has actually been sampled and investigated. We currently perceive most of the deep-sea ecosystems as heterotrophic, depending ultimately on the flux on organic matter produced in the overlying surface ocean through photosynthesis. The resulting strong food limitation thus shapes deep-sea biota and communities, with exceptions only in reducing ecosystems such as inter alia hydrothermal vents or cold seeps. Here, chemoautolithotrophic bacteria play the role of primary producers fuelled by chemical energy sources rather than sunlight. Other ecosystems, such as seamounts, canyons or cold

  4. Business Subsidies in Canada Comprehensive Estimates for the Government of Canada and the Four Largest Provinces

    Directory of Open Access Journals (Sweden)

    John Lester

    2018-01-01

    Full Text Available Business subsidies in Canada: the “winner” is Alberta; the loser is the taxpayer The federal government and the four largest provinces in Canada spend about $29 billion a year on business subsidies, delivered through program spending, the tax system, government business enterprises and direct investments by government. These subsidies represent almost half of the corporate income tax revenue collected by the five jurisdictions. Surprisingly, given its reputation as a bastion of free enterprise, Alberta is the most prolific subsidizer. In the 2014-15 fiscal year, per person subsidies were $640 in Alberta, about $100 ahead of the next most generous jurisdiction, Québec. Alberta has probably added to its “lead” through measures introduced in the October 2015 Fiscal Update and the 2016 budget. Alberta also stands out by having the least transparent public reporting of business subsidies. What motivates governments to subsidize business? Abstracting from cynical efforts to win votes, business subsidies have two broad objectives: to improve economic performance and to achieve a social objective by supporting specific firms, industries or regions. On average in the five jurisdictions, the split between the two categories is about 70-30 in favour of economic development measures. Assessing value for money from programs with a social objective is subjective, but measures intended to improve economic performance should be assessed on their ability to raise real income. Business subsidies can only raise real income if markets fail to allocate labour and capital to their best uses. The classic case is R&D. When a firm undertakes R&D, some of the knowledge created inevitably spills over to the benefit other firms. Firms are focused on their own benefits and costs when deciding how much to spend on R&D, not the benefits received by other firms, so society has an interest in encouraging additional R&D. While markets generally do a good job allocating

  5. Plant species and communities in Poyang Lake, the largest freshwater lake in China

    Directory of Open Access Journals (Sweden)

    Wang, H. F.

    2015-12-01

    Full Text Available Studying plant species richness and composition of a wetland is essential when estimating its ecological importance and ecosystem services, especially if a particular wetland is subjected to human disturbances. Poyang Lake, located in the middle reaches of Yangtze River (central China, constitutes the largest freshwater lake of the country. It harbours high biodiversity and provides important habitat for local wildlife. A dam that will maintain the water capacity in Poyang Lake is currently being planned. However, the local biodiversity and the likely effects of this dam on the biodiversity (especially on the endemic and rare plants have not been thoroughly examined. Therefore, in order to assess the richness of plant species and plant communities in Poyang Lake, we conducted a detailed field investigation combined with a literature review. A total of 124 families, 339 genera, and 512 species (including sub-species, varieties and forms as well as eight dominant plant communities were identified, confirming the lake’s wetland as a regional hotspot of plant diversity. It is imperative to carry out further research on the impact of damming on the vegetation, particularly research focusing on protecting local biodiversity, maintaining the lake’s ecosystem services, controlling the spread of invasive species, and restoring degraded ecosystems.El estudio de la riqueza y la composición de especies vegetales de un humedal es esencial a la hora de estimar su importancia ecológica y sus servicios ecosistémicos, especialmente cuando éste está sujeto a perturbaciones humanas. El lago Poyang, situado en el curso medio del río Yangtsé (China central constituye la mayor superfície de agua dulce del país. Alberga una elevada biodiversidad y proporciona hábitats importantes para la flora y fauna locales. En la actualidad existen planes de construir una presa que mantendrá el volumen de agua del lago estable. Sin embargo, y hasta la fecha, apenas

  6. Zymography methods for visualizing hydrolytic enzymes

    OpenAIRE

    Vandooren, Jennifer; Geurts, Nathalie; Martens, Erik; Van den Steen, Philippe E.; Opdenakker, Ghislain

    2013-01-01

    Zymography is a technique for studying hydrolytic enzymes on the basis of substrate degradation. It is a powerful., but often misinterpreted, tool. yielding information on potential. hydrolytic activities, enzyme forms and the locations of active enzymes. In this Review, zymography techniques are compared in terms of advantages, limitations and interpretations. With in gel zymography, enzyme forms are visualized according to their molecular weights. Proteolytic activities are localized in tis...

  7. Biomedical Applications of Enzymes From Marine Actinobacteria.

    Science.gov (United States)

    Kamala, K; Sivaperumal, P

    Marine microbial enzyme technologies have progressed significantly in the last few decades for different applications. Among the various microorganisms, marine actinobacterial enzymes have significant active properties, which could allow them to be biocatalysts with tremendous bioactive metabolites. Moreover, marine actinobacteria have been considered as biofactories, since their enzymes fulfill biomedical and industrial needs. In this chapter, the marine actinobacteria and their enzymes' uses in biological activities and biomedical applications are described. © 2017 Elsevier Inc. All rights reserved.

  8. Ownership, financing, and management strategies of the ten largest for-profit nursing home chains in the United States.

    Science.gov (United States)

    Harrington, Charlene; Hauser, Clarilee; Olney, Brian; Rosenau, Pauline Vaillancourt

    2011-01-01

    This study examined the ownership, financing, and management strategies of the 10 largest for-profit nursing home chains in the United States, including the four largest chains purchased by private equity corporations. Descriptive data were collected from Internet searches, company reports, and other sources for the decade 1998-2008. Since 1998, the largest chains have made many changes in their ownership and structure, and some have converted from publicly traded companies to private ownership. This study shows the increasing complexity of corporate nursing home ownership and the lack of public information about ownership and financial status. The chains have used strategies to maximize shareholder and investor value that include increasing Medicare revenues, occupancy rates, and company diversification, establishing multiple layers of corporate ownership, developing real estate investment trusts, and creating limited liability companies. These strategies enhance shareholder and investor profits, reduce corporate taxes, and reduce liability risk. There is a need for greater transparency in ownership and financial reporting and for more government oversight of the largest for-profit chains, including those owned by private equity companies.

  9. Haven't We Been Here Before? Some Comments on Steve Coffman's Proposal for "Earth's Largest Library".

    Science.gov (United States)

    McGervey, Teresa

    2000-01-01

    Discusses the concept of Earth's Largest Library (ELL), a mega-virtual library based on the Amazon.com model. Topics include who will be included; privacy; censorship; scope of the collection; costs; legal aspects; collection development; personnel management; access; the concept of community; public service; lending policies; technical…

  10. Estimate of the largest Lyapunov characteristic exponent of a high dimensional atmospheric global circulation model: a sensitivity analysis

    International Nuclear Information System (INIS)

    Guerrieri, A.

    2009-01-01

    In this report the largest Lyapunov characteristic exponent of a high dimensional atmospheric global circulation model of intermediate complexity has been estimated numerically. A sensitivity analysis has been carried out by varying the equator-to-pole temperature difference, the space resolution and the value of some parameters employed by the model. Chaotic and non-chaotic regimes of circulation have been found. [it

  11. Estimating the recreational value of Pakistan's largest freshwater lake to support sustainable tourism management using a travel cost model

    NARCIS (Netherlands)

    Mangan, T.; Brouwer, R.; Lohano, H.; Nagraj, G.M.

    2013-01-01

    Keenjhar Lake, Pakistan's largest freshwater lake and an important Ramsar site, provides habitat for internationally important water birds. Annually, 385,000 people visit the lake. The lake is threatened by a variety of causes, including industrial and agricultural pollution. To support its

  12. German Migrant Teachers in Australia: Insights into the Largest Cohort of Non-English Speaking Background Teachers

    Science.gov (United States)

    Bense, Katharina

    2015-01-01

    The research reported in this paper investigates the situation of German migrant teachers in Australia. Although German born teachers represent the largest group of non-English speaking background teachers in Australia, there is no study of the circumstances and experiences of these teachers in Australia. This study aims to fill this gap. It…

  13. The Determinants of Bank Internationalisation in Times of Financial Globalisation: Evidence from the World's Largest Banks (1980-2007)

    NARCIS (Netherlands)

    Westerhuis, Gerarda; Mulder, Arjen

    2015-01-01

    This article analyses the determinants of bank internationalisation, of the world's largest banks from the period 1980–2007. The purpose of the article is twofold. First, we show how a mixed-methods research design, in which we combine a variables-based research with three case studies, can

  14. Pay less, take more: the myth of quality of life at the Brazil’s largest drugstore chain counter

    Directory of Open Access Journals (Sweden)

    André Luiz Maranhão de Souza Leão

    2013-06-01

    Full Text Available Considering the role of cultural transformer that the brandoccupies in the contemporary and seeking to delineate the role played bymyth in this construction, we look at Pague Menos, the largest pharmacyretail network in the country, through a qualitative study based on Barthesiansemiology. Our results showed six myths, whose relationships reveal ametanarrative: the quality of life.

  15. Cellulolytic enzyme compositions and uses thereof

    Energy Technology Data Exchange (ETDEWEB)

    Iyer, Prashant; Gaspar, Armindo Ribiero; Croonenberghs, James; Binder, Thomas P.

    2017-07-25

    The present invention relates enzyme composition comprising a cellulolytic preparation and an acetylxylan esterase (AXE); and the used of cellulolytic enzyme compositions for hydrolyzing acetylated cellulosic material. Finally the invention also relates to processes of producing fermentation products from acetylated cellulosic materials using a cellulolytic enzyme composition of the invention.

  16. Immobilization of Enzymes in Polymer Supports.

    Science.gov (United States)

    Conlon, Hugh D.; Walt, David R.

    1986-01-01

    Two experiments in which an enzyme is immobilized onto a polymeric support are described. The experiments (which also demonstrate two different polymer preparations) involve: (1) entrapping an enzyme in an acrylamide polymer; and (2) reacting the amino groups on the enzyme's (esterase) lysine residues with an activated polymer. (JN)

  17. Purification and characterization of extracellular amylolytic enzyme ...

    African Journals Online (AJOL)

    In the present study, the amylase enzyme producing potential of four different Aspergillus species was analyzed. The extracted amylase enzyme was purified by diethyl amino ethyl (DEAE) cellulose and Sephadex G-50 column chromatography and the enzyme activity was measured by using synthetic substrate starch.

  18. Activation of interfacial enzymes at membrane surfaces

    DEFF Research Database (Denmark)

    Mouritsen, Ole G.; Andresen, Thomas Lars; Halperin, Avi

    2006-01-01

    A host of water-soluble enzymes are active at membrane surfaces and in association with membranes. Some of these enzymes are involved in signalling and in modification and remodelling of the membranes. A special class of enzymes, the phospholipases, and in particular secretory phospholipase A2 (s...

  19. PROCESS FOR DUST-FREE ENZYME MANUFACTURE

    NARCIS (Netherlands)

    Andela, C.; Feijen, Jan; Dillissen, Marc

    1994-01-01

    New enzyme granules are provided with improved properties. The granules are based on core particles having a good pore size and pore size distribution to allow an enzyme solution to enter into the particle. Accordingly, the core material comprises the enzyme in liquid form, thus eliminating the

  20. Combining polysaccharide biosynthesis and transport in a single enzyme: dual-function cell wall glycan synthases.

    Directory of Open Access Journals (Sweden)

    Jonathan Kent Davis

    2012-06-01

    Full Text Available Extracellular polysaccharides are synthesized by a wide variety of species, from unicellular bacteria and Archaea to the largest multicellular plants and animals in the biosphere. In every case, the biosynthesis of these polymers requires transport across a membrane, from the cytosol to either the lumen of secretory pathway organelles or directly into the extracellular space. Although some polysaccharide biosynthetic substrates are moved across the membrane to sites of polysaccharide synthesis by separate transporter proteins before being incorporated into polymers by glycosyltransferase proteins, many polysaccharide biosynthetic enzymes appear to have both transporter and transferase activities. In these cases, the biosynthetic enzymes utilize substrate on one side of the membrane and deposit the polymer product on the other side. This review discusses structural characteristics of plant cell wall glycan synthases that couple synthesis with transport, drawing on what is known about such dual-function enzymes in other species.

  1. Screening for Extracellular Lipase Enzymes with Transesterification Capacity in Mucoromycotina Strains

    Directory of Open Access Journals (Sweden)

    Alexandra Kotogán

    2014-01-01

    Full Text Available In this study, 169 zygomycetes fungal strains including some cold-tolerant isolates were screened for their extracellular lipolytic activity towards tributyrin. Nineteen of them were outstanding in their enzyme production as they developed the largest lipolytic halo around the colonies in plate tests. Mortierella alpina, M. echinosphaera, Mucor corticolus, Rhizomucor miehei, Rhizopus oryzae, Rh. stolonifer, Umbelopsis autotrophica, U. isabellina, U. ramanniana var. angulispora and U. versiformis were selected for further studies to characterise their lipolytic enzyme production in detail. In these assays, effect of Tween 80 and palm, soybean, sunflower, olive, extra virgin olive, wheat germ, corn germ, sesame seed, pumpkin seed and cottonseed oils on the enzyme activities was investigated, and wheat bran-based submerged and solid-state fermentations were also tested. Tween 80 and olive oil proved to be efficient inductors for lipolytic enzyme production, which was also enhanced when wheat bran was used as support. Addition of mineral salts and olive oil to the solid fermentation medium resulted in at least 1.5-fold increment in the enzyme activities of the crude extracts. Organic synthesis was also assayed by the selected lipases, in which enzymes from the fungi R. miehei, Rh. stolonifer and M. echinosphaera gave the best yields during transesterification reactions between p-nitrophenyl palmitate and ethanol.

  2. Enzyme structure and interaction with inhibitors

    International Nuclear Information System (INIS)

    London, R.E.

    1983-01-01

    This article reviews some of the results of studies on the 13 C-labeled enzyme dihydrofolate reductase (DHFR). Nuclear magnetic resonance (NMR) techniques are used in combination with isotopic labeling to learn about the structure and dynamics of this enzyme. 13 C-labeling is used for the purpose of studying enzyme/substrate and enzyme/inhibitor interactions. A second set of studies with DHFR was designed to investigate the basis for the high affinity between the inhibitor methotrexate and DHFR. The label was placed on the inhibitor, rather than the enzyme

  3. Applications of Microbial Enzymes in Food Industry

    Directory of Open Access Journals (Sweden)

    Binod Parameswaran

    2018-01-01

    Full Text Available The use of enzymes or microorganisms in food preparations is an age-old process. With the advancement of technology, novel enzymes with wide range of applications and specificity have been developed and new application areas are still being explored. Microorganisms such as bacteria, yeast and fungi and their enzymes are widely used in several food preparations for improving the taste and texture and they offer huge economic benefits to industries. Microbial enzymes are the preferred source to plants or animals due to several advantages such as easy, cost-effective and consistent production. The present review discusses the recent advancement in enzyme technology for food industries. A comprehensive list of enzymes used in food processing, the microbial source of these enzymes and the wide range of their application are discussed.

  4. DNA-Based Enzyme Reactors and Systems

    Directory of Open Access Journals (Sweden)

    Veikko Linko

    2016-07-01

    Full Text Available During recent years, the possibility to create custom biocompatible nanoshapes using DNA as a building material has rapidly emerged. Further, these rationally designed DNA structures could be exploited in positioning pivotal molecules, such as enzymes, with nanometer-level precision. This feature could be used in the fabrication of artificial biochemical machinery that is able to mimic the complex reactions found in living cells. Currently, DNA-enzyme hybrids can be used to control (multi-enzyme cascade reactions and to regulate the enzyme functions and the reaction pathways. Moreover, sophisticated DNA structures can be utilized in encapsulating active enzymes and delivering the molecular cargo into cells. In this review, we focus on the latest enzyme systems based on novel DNA nanostructures: enzyme reactors, regulatory devices and carriers that can find uses in various biotechnological and nanomedical applications.

  5. The largest Fresco in Europe on cooling tower of nuclear power station of Cruas Meysse in Ardeche, France

    International Nuclear Information System (INIS)

    Di Mayo, J.L.

    1993-01-01

    The Nuclear Power Station Cruas Meysse is on the most important communication way of France, in the Rhone Valley, between the Rhin and the Mediterranean Sea. In the South of the Rhone Valley, the Nuclear Power Plant is situated near the very important site of 'Tricastin', the largest nuclear area in France. Cruas Meysse has a very good integration to the economy, social, and cultural scheme ; that's why EDF and the Ardeche Department had enter into partnership to associate art and technology of our time, and offer a work for everybody - 'Le Verseau' is the largest fresco in Europe - It gives a gigantic signalling system to the Ardeche Department, because the Nuclear Power Station has a very interesting position, close the motor way A7, the National 7 road, and the way of high speed train (TGV) an another symbol of the high French technology

  6. Invasive fish species in the largest lakes of Scotland, Northern Ireland, Wales and England: the collective U.K. experience

    OpenAIRE

    Winfield, I.J.; Fletcher, J.M.; James, J.B.

    2011-01-01

    An invasive species is defined as an alien (or introduced or non-native) species whose establishment and spread threaten ecosystems, habitats or species with harm. Such threats to UK lake fish communities have long been appreciated and this review assembles case histories, including new data, from the largest lakes of Scotland, Northern Ireland, Wales and England to examine the hypothesis that at least some of these introductions have become invasive. Loch Lomond in Scotland has experienced s...

  7. Survival of Extremely Premature Infants at the Largest MOH Referral Hospital in UAE: Comparable Results to Developed Countries

    OpenAIRE

    YASEEN, Hakam; YASEEN, Hoda

    2010-01-01

    Objective: to investigate the survival rate of extreme premature infants born between 2000 and 2008 at AL Qassimi hospital that is the largest Ministry of Health (MOH) referral hospital in the United Arab Emirates (UAE).Methods: This was an institutional review board approved retrospective study of the outcomes of pregnancies in women who were in labor and delivered between 23 and 25 weeks' completed gestation at Al Qassimi Hospital in the Emirate of Sharjah between January 1,2000 and De...

  8. Mapping Dynamics of Inundation Patterns of Two Largest River-Connected Lakes in China: A Comparative Study

    OpenAIRE

    Guiping Wu; Yuanbo Liu

    2016-01-01

    Poyang Lake and Dongting Lake are the two largest freshwater lakes in China. The lakes are located approximately 300 km apart on the middle reaches of the Yangtze River and are differently connected through their respective tributary systems, which will lead to different river–lake water exchanges and discharges. Thus, differences in their morphological and hydrological conditions should induce individual lake spatio-temporal inundation patterns. Quantitative comparative analyses of the dynam...

  9. The largest forest fires in Portugal: the constraints of burned area size on the comprehension of fire severity.

    Science.gov (United States)

    Tedim, Fantina; Remelgado, Ruben; Martins, João; Carvalho, Salete

    2015-01-01

    Portugal is a European country with highest forest fires density and burned area. Since beginning of official forest fires database in 1980, an increase in number of fires and burned area as well as appearance of large and catastrophic fires have characterized fire activity in Portugal. In 1980s, the largest fires were just a little bit over 10,000 ha. However, in the beginning of 21st century several fires occurred with a burned area over 20,000 ha. Some of these events can be classified as mega-fires due to their ecological and socioeconomic severity. The present study aimed to discuss the characterization of large forest fires trend, in order to understand if the largest fires that occurred in Portugal were exceptional events or evidences of a new trend, and the constraints of fire size to characterize fire effects because, usually, it is assumed that larger the fire higher the damages. Using Portuguese forest fire database and satellite imagery, the present study showed that the largest fires could be seen at the same time as exceptional events and as evidence of a new fire regime. It highlighted the importance of size and patterns of unburned patches within fire perimeter as well as heterogeneity of fire ecological severity, usually not included in fire regime description, which are critical to fire management and research. The findings of this research can be used in forest risk reduction and suppression planning.

  10. Ethanologenic Enzymes of Zymomonas mobilis

    Energy Technology Data Exchange (ETDEWEB)

    Ingram, Lonnie O' Neal

    1999-03-01

    Zymomonas mobilis is a unique microorganism in being both obligately fermentative and utilizing a Entner-Doudoroff pathway for glycolysis. Glycolytic flux in this organism is readily measured as evolved carbon dioxide, ethanol, or glucose consumed and exceeds 1 {micro}mole glucose/min per mg cell protein. To support this rapid glycolysis, approximately 50% of cytoplasmic protein is devoted to the 13 glycolytic and fermentative enzymes which constitute this central catabolic pathway. Only 1 ATP (net) is produced from each glucose metabolized. During the past grant period, we have completed the characterization of 11 of the 13 glycolytic genes from Z. mobilis together with complementary but separate DOE-fimded research by a former post-dot and collaborator, Dr. Tyrrell Conway. Research funded in my lab by DOE, Division of Energy Biosciences can be divided into three sections: A. Fundamental studies; B. Applied studies and utility; and C. Miscellaneous investigations.

  11. CELLULOSE DEGRADATION BY OXIDATIVE ENZYMES

    Directory of Open Access Journals (Sweden)

    Maria Dimarogona

    2012-09-01

    Full Text Available Enzymatic degradation of plant biomass has attracted intensive research interest for the production of economically viable biofuels. Here we present an overview of the recent findings on biocatalysts implicated in the oxidative cleavage of cellulose, including polysaccharide monooxygenases (PMOs or LPMOs which stands for lytic PMOs, cellobiose dehydrogenases (CDHs and members of carbohydrate-binding module family 33 (CBM33. PMOs, a novel class of enzymes previously termed GH61s, boost the efficiency of common cellulases resulting in increased hydrolysis yields while lowering the protein loading needed. They act on the crystalline part of cellulose by generating oxidized and non-oxidized chain ends. An external electron donor is required for boosting the activity of PMOs. We discuss recent findings concerning their mechanism of action and identify issues and questions to be addressed in the future.

  12. Time compression of soil erosion by the effect of largest daily event. A regional analysis of USLE database.

    Science.gov (United States)

    Gonzalez-Hidalgo, J. C.; Batalla, R.; Cerda, A.; de Luis, M.

    2009-04-01

    When Thornes and Brunsden wrote in 1977 "How often one hears the researcher (and no less the undergraduate) complain that after weeks of observation "nothing happened" only to learn that, the day after his departure, a flood caused unprecedent erosion and channel changes!" (Thornes and Brunsden, 1977, p. 57), they focussed on two different problems in geomorphological research: the effects of extreme events and the temporal compression of geomorphological processes. The time compression is one of the main characteristic of erosion processes. It means that an important amount of the total soil eroded is produced in very short temporal intervals, i.e. few events mostly related to extreme events. From magnitude-frequency analysis we know that few events, not necessarily extreme by magnitude, produce high amount of geomorphological work. Last but not least, extreme isolated events are a classical issue in geomorphology by their specific effects, and they are receiving permanent attention, increased at present because of scenarios of global change. Notwithstanding, the time compression of geomorphological processes could be focused not only on the analysis of extreme events and the traditional magnitude-frequency approach, but on new complementary approach based on the effects of largest events. The classical approach define extreme event as a rare event (identified by its magnitude and quantified by some deviation from central value), while we define largest events by the rank, whatever their magnitude. In a previous research on time compression of soil erosion, using USLE soil erosion database (Gonzalez-Hidalgo et al., EGU 2007), we described a relationship between the total amount of daily erosive events recorded by plot and the percentage contribution to total soil erosion of n-largest aggregated daily events. Now we offer a further refined analysis comparing different agricultural regions in USA. To do that we have analyzed data from 594 erosion plots from USLE

  13. Prediction of Wild-type Enzyme Characteristics

    DEFF Research Database (Denmark)

    Geertz-Hansen, Henrik Marcus

    of biotechnology, including enzyme discovery and characterization. This work presents two articles on sequence-based discovery and functional annotation of enzymes in environmental samples, and two articles on analysis and prediction of enzyme thermostability and cofactor requirements. The first article presents...... a sequence-based approach to discovery of proteolytic enzymes in metagenomes obtained from the Polar oceans. We show that microorganisms living in these extreme environments of constant low temperature harbour genes encoding novel proteolytic enzymes with potential industrial relevance. The second article...... presents a web server for the processing and annotation of functional metagenomics sequencing data, tailored to meet the requirements of non-bioinformaticians. The third article presents analyses of the molecular determinants of enzyme thermostability, and a feature-based prediction method of the melting...

  14. Toward mechanistic classification of enzyme functions.

    Science.gov (United States)

    Almonacid, Daniel E; Babbitt, Patricia C

    2011-06-01

    Classification of enzyme function should be quantitative, computationally accessible, and informed by sequences and structures to enable use of genomic information for functional inference and other applications. Large-scale studies have established that divergently evolved enzymes share conserved elements of structure and common mechanistic steps and that convergently evolved enzymes often converge to similar mechanisms too, suggesting that reaction mechanisms could be used to develop finer-grained functional descriptions than provided by the Enzyme Commission (EC) system currently in use. Here we describe how evolution informs these structure-function mappings and review the databases that store mechanisms of enzyme reactions along with recent developments to measure ligand and mechanistic similarities. Together, these provide a foundation for new classifications of enzyme function. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. How Do Enzymes 'Meet' Nanoparticles and Nanomaterials?

    Science.gov (United States)

    Chen, Ming; Zeng, Guangming; Xu, Piao; Lai, Cui; Tang, Lin

    2017-11-01

    Enzymes are fundamental biological catalysts responsible for biological regulation and metabolism. The opportunity for enzymes to 'meet' nanoparticles and nanomaterials is rapidly increasing due to growing demands for applications in nanomaterial design, environmental monitoring, biochemical engineering, and biomedicine. Therefore, understanding the nature of nanomaterial-enzyme interactions is becoming important. Since 2014, enzymes have been used to modify, degrade, or make nanoparticles/nanomaterials, while numerous nanoparticles/nanomaterials have been used as materials for enzymatic immobilization and biosensors and as enzyme mimicry. Among the various nanoparticles and nanomaterials, metal nanoparticles and carbon nanomaterials have received extensive attention due to their fascinating properties. This review provides an overview about how enzymes meet nanoparticles and nanomaterials. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Production of Enzymes from Marine Actinobacteria.

    Science.gov (United States)

    Zhao, X Q; Xu, X N; Chen, L Y

    Marine actinobacteria are well recognized for their capabilities to produce valuable natural products, which have great potential for applications in medical, agricultural, and fine chemical industries. In addition to producing unique enzymes responsible for biosynthesis of natural products, many marine actinobacteria also produce hydrolytic enzymes which are able to degrade various biopolymers, such as cellulose, xylan, and chitin. These enzymes are important to produce biofuels and biochemicals of interest from renewable biomass. In this chapter, the recent reports of novel enzymes produced by marine actinobacteria are reviewed, and advanced technologies that can be applied to search for novel marine enzymes as well as for improved enzyme production by marine actinobacteria are summarized, which include ribosome engineering, genome mining, as well as synthetic biology studies. © 2016 Elsevier Inc. All rights reserved.

  17. Evaluation of pressure tuning of enzymes

    DEFF Research Database (Denmark)

    Naghshineh, Mahsa

    and high energy consumption. Therefore, searching for an environmentally friendly method of pectin extraction is a task for science and industry. Employment of hydrolytic enzymes may represent a green approach to obtain intact pectin polymer. However, the low stability/activity of enzymes, and low polymer...... yield of enzymatic extraction limits the application of enzyme in pectin production. There is evidence that emerging technology of high hydrostatic pressure processing can result in stabilization and activation of some enzymes. Therefore, the use of high hydrostatic pressure in combination with enzyme...... (cellulase/xylanase: 50/0, 50/25, 50/50, 25/50, and 0/50 U/g lime peel) at ambient pressure, 100 and 200 MPa were used to extract pectin from dried lime peel waste. It was found that pressure level, type and concentration of enzyme significantly influenced pectin yield and degree of esterification (DE...

  18. Enzyme Enzyme activities in relation to sugar accumulation in tomato

    International Nuclear Information System (INIS)

    Alam, M.J.; Rahman, M.H.; Mamun, M.A.; Islam, K.

    2006-01-01

    Enzyme activities in tomato juice of five different varieties viz. Ratan, Marglove, BARI-1, BARI-5 and BARI-6, in relation to sugar accumulation were investigated at different maturity stages. The highest amount of invertase and beta-galactosidase was found in Marglove and the lowest in BARI- 6 at all maturity stages. Total soluble sugar and sucrose contents were highest in BARI-1 and lowest in BARI-6. The activity of amylase was maximum in Ratan and minimum in Marglove. Protease activity was highest in Ratan and lowest in BARI-6. BARI-1 contained the highest cellulase activity and the lowest in BARI-5. The amount of total soluble sugar and sucrose increased moderately from premature to ripe stage. The activities of amylase and cellulase increased up to the mature stage and then decreased drastically in the ripe stage. The activities of invertase and protease increased sharply from the premature to the ripe stage while the beta-galactosidase activity decreased remarkably. No detectable amount of reducing sugar was present in the premature stage in all cultivars of tomato but increased thereafter upto the ripe stage. The highest reducing sugar was present in BARI-5 in all of the maturity stages. (author)

  19. ENZYME RESISTANCE OF GENETICALLY MODIFIED STARCH POTATOES

    Directory of Open Access Journals (Sweden)

    A. Sh. Mannapova

    2015-01-01

    Full Text Available Here in this article the justification of expediency of enzyme resistant starch use in therapeutic food products is presented . Enzyme resistant starch is capable to resist to enzymatic hydrolysis in a small intestine of a person, has a low glycemic index, leads to decrease of postprandial concentration of glucose, cholesterol, triglycerides in blood and insulin reaction, to improvement of sensitivity of all organism to insulin, to increase in sense of fulness and to reduction of adjournment of fats. Resistant starch makes bifidogenшс impact on microflora of a intestine of the person, leads to increase of a quantity of lactobacillus and bifidobacterium and to increased production of butyric acid in a large intestine. In this regard the enzyme resistant starch is an important component in food for prevention and curing of human diseases such as diabetes, obesity, colitis, a cancer of large and direct intestine. One method is specified by authors for imitation of starch digestion in a human body. This method is based on the definition of an enzyme resistance of starch in vitro by its hydrolysis to glucose with application of a glucoamylase and digestive enzyme preparation Pancreatin. This method is used in researches of an enzyme resistance of starch, of genetically modified potato, high amylose corn starch Hi-Maize 1043 and HYLON VII (National Starch Food Innovation, USA, amylopectin and amylose. It is shown that the enzyme resistance of the starch emitted from genetically modified potatoes conforms to the enzyme resistance of the high amylose corn starch “Hi-Maize 1043 and HYLON VII starch”, (National Starch Food Innovation, the USA relating to the II type of enzyme resistant starch. It is established that amylopectin doesn't have the enzyme resistant properties. The results of researches are presented. They allow us to make the following conclusion: amylose in comparison with amylopectin possesses higher enzyme resistance and gives to

  20. [Advances on enzymes and enzyme inhibitors research based on microfluidic devices].

    Science.gov (United States)

    Hou, Feng-Hua; Ye, Jian-Qing; Chen, Zuan-Guang; Cheng, Zhi-Yi

    2010-06-01

    With the continuous development in microfluidic fabrication technology, microfluidic analysis has evolved from a concept to one of research frontiers in last twenty years. The research of enzymes and enzyme inhibitors based on microfluidic devices has also made great progress. Microfluidic technology improved greatly the analytical performance of the research of enzymes and enzyme inhibitors by reducing the consumption of reagents, decreasing the analysis time, and developing automation. This review focuses on the development and classification of enzymes and enzyme inhibitors research based on microfluidic devices.

  1. Zymography methods for visualizing hydrolytic enzymes.

    Science.gov (United States)

    Vandooren, Jennifer; Geurts, Nathalie; Martens, Erik; Van den Steen, Philippe E; Opdenakker, Ghislain

    2013-03-01

    Zymography is a technique for studying hydrolytic enzymes on the basis of substrate degradation. It is a powerful, but often misinterpreted, tool yielding information on potential hydrolytic activities, enzyme forms and the locations of active enzymes. In this Review, zymography techniques are compared in terms of advantages, limitations and interpretations. With in gel zymography, enzyme forms are visualized according to their molecular weights. Proteolytic activities are localized in tissue sections with in situ zymography. In vivo zymography can pinpoint proteolytic activity to sites in an intact organism. Future development of novel substrate probes and improvement in detection and imaging methods will increase the applicability of zymography for (reverse) degradomics studies.

  2. Detoxification enzymes activities in deltamethrin and bendiocarb ...

    African Journals Online (AJOL)

    Detoxification enzymes activities in deltamethrin and bendiocarb resistant and susceptible malarial vectors ( Anopheles gambiae ) breeding in Bichi agricultural and residential sites, Kano state, Nigeria.

  3. Escherichia coli photoreactivating enzyme: purification and properties

    International Nuclear Information System (INIS)

    Snapka, R.M.; Sutherland, B.M.

    1980-01-01

    Researchers have purified large quantities of Escherichia coli photoreactivating enzyme to apparent homogeneity and have studied its physical and chemical properties. The enzyme has a molecular weight of 36,800 and a S/sub 20,w/ 0 of 3.72 S. Amino acid analysis revealed an apparent absence of tryptophan, a low content of aromatic residues, and the presence of no unusual amino acids. The N terminus is arginine. The purified enzyme contained up to 13% carbohydrate by weight. The carbohydrate was composed of mannose, galactose, glucose, and N-acetylglucosamine. The enzyme is also associated with RNA containing uracil, adenine, guanine, and cytosine with no unusual bases detected

  4. Thermometric enzyme linked immunosorbent assay: TELISA.

    Science.gov (United States)

    Mattiasson, B; Borrebaeck, C; Sanfridson, B; Mosbach, K

    1977-08-11

    A new method, thermometric enzyme linked immunosorbent assay (TELISA), for the assay of endogenous and exogenous compounds in biological fluids is described. It is based on the previously described enzyme linked immunosorbent assay technique, ELISA, but utilizes enzymic heat formation which is measured in an enzyme thermistor unit. In the model system studied determination of human serum albumin down to a concentration of 10(-10) M (5 ng/ml) was achieved, with both normal and catalase labelled human serum albumin competing for the binding sites on the immunosorbent, which was rabbit antihuman serum albumin immobilized onto Sepharose CL-4B.

  5. The mechanisms of Excited states in enzymes

    DEFF Research Database (Denmark)

    Petersen, Frederic Nicolas Rønne; Bohr, Henrik

    2010-01-01

    Enzyme catalysis is studied on the basis of excited state processes, which are of electronic, vibrational and thermal nature. The ways of achieving the excited state, such as photo-absorption and ligand binding, are discussed and exemplified by various cases of enzymes.......Enzyme catalysis is studied on the basis of excited state processes, which are of electronic, vibrational and thermal nature. The ways of achieving the excited state, such as photo-absorption and ligand binding, are discussed and exemplified by various cases of enzymes....

  6. Proteomic analysis and food-grade enzymes of Moringa oleifer Lam. a Lam. flower.

    Science.gov (United States)

    Shi, Yanan; Wang, Xuefeng; Huang, Aixiang

    2018-08-01

    Moringa oleifer Lam. flower contain high-proteins and function nutrients. Many advances have been made to it, but there is still no proteomic information of this species. Total protein from the flowers applied shotgun 2DLC-MS/MS proteomic identified 9443 peptides corresponding to 4004 high-confidence proteins by Proteome Discoverer™ Software 2.1. These proteins were mostly distributed ranging between 40 and 70 kDa. Gene Ontology (GO) analysis indicated that the largest of the proteins were cytoplasm 72.7%, catalytic activity 61.5% and macromolecule metabolism 43.7%, and KEGG analysis revealed that the largest group of 129 proteins was involved in Ribosome to directing protein synthesis (translation). Moreover, a number of commercially important food-grade enzymes were commented, 261 proteins were annotated as carbohydrate-active enzymes, 16 protease, 22 proteins are assigned to the citrate cycle, which the top proteins were assigned to GH family, cysteine synthase and serine/threonine-protein phosphatase. These enzymes indicated that is a new source with potential use for fermentation and brewing industry, fruit and vegetable storage and the development of function peptides. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. MUREIN-METABOLIZING ENZYMES FROM ESCHERICHIA-COLI - SEQUENCE-ANALYSIS AND CONTROLLED OVEREXPRESSION OF THE SLT GENE, WHICH ENCODES THE SOLUBLE LYTIC TRANSGLYCOSYLASE

    NARCIS (Netherlands)

    ENGEL, H; KAZEMIER, B; KECK, W

    The complete nucleotide sequence of the slt gene encoding the soluble lytic transglycosylase (Slt; EC 3.2.1.-) from Escherichia coli has been determined. The largest open reading frame identified on a 2.5-kb PvuII-SalI fragment indicates that the enzyme is translated as a preprotein of either 654 or

  8. Sweden's largest Facebook study

    OpenAIRE

    Denti, Leif; Barbopoulus, Isak; Nilsson, Ida; Holmberg, Linda; Thulin, Magdalena; Wendeblad, Malin; Andén, Lisa; Davidsson, Emelie

    2012-01-01

    The emergence of the Internet has made it easier for people to socially interact than ever before. Today, the most popular channel is Facebook with over 845 million users world wide. In Sweden, the number of users amount to approximately half of the population. We had two aims with this study. First, we investigate which areas of Facebook usage that Swedish Facebook users consider more important vis-a-vis less important. We were also interested in how users convey their persona through t... m...

  9. Largest terrestrial electromagnetic pulsar

    Czech Academy of Sciences Publication Activity Database

    Pardy, Miroslav

    2002-01-01

    Roč. 46, č. 6 (2002), s. 1155-1163 ISSN 0020-7748 R&D Projects: GA MŠk LN00A100 Institutional research plan: CEZ:AV0Z2043910 Keywords : source theory, spectral formula, synchrotron radiation Subject RIV: BE - Theoretical Physics Impact factor: 0.655, year: 2002

  10. Spectroscopic studies of copper enzymes

    International Nuclear Information System (INIS)

    Dooley, D.M.; Moog, R.; Zumft, W.; Koenig, S.H.; Scott, R.A.; Cote, C.E.; McGuirl, M.

    1986-01-01

    Several spectroscopic methods, including absorption, circular dichroism (CD), magnetic CD (MCD), X-ray absorption, resonance Raman, EPR, NMR, and quasi-elastic light-scattering spectroscopy, have been used to probe the structures of copper-containing amine oxidases, nitrite reductase, and nitrous oxide reductase. The basic goals are to determine the copper site structure, electronic properties, and to generate structure-reactivity correlations. Collectively, the results on the amine oxidases permit a detailed model for the Cu(II) sites in these enzymes to be constructed that, in turn, rationalizes the ligand-binding chemistry. Resonance Raman spectra of the phenylhydrazine and 2,4-dinitrophenyl-hydrazine derivatives of bovine plasma amine oxidase and models for its organic cofactor, e.g. pyridoxal, methoxatin, are most consistent with methoxatin being the intrinsic cofactor. The structure of the Cu(I) forms of the amine oxidases have been investigated by X-ray absorption spectroscopy (XAS); the copper coordination geometry is significantly different in the oxidized and reduced forms. Some anomalous properties of the amine oxidases in solution are explicable in terms of their reversible aggregation, which the authors have characterized via light scattering. Nitrite and nitrous oxide reductases display several novel spectral properties. The data suggest that new types of copper sites are present

  11. World's largest DC flywheel generator for the toroidal field power supply of JAERI's JFT-2M Tokamak nuclear fusion reactor

    International Nuclear Information System (INIS)

    Tani, Takashi; Nakanishi, Yuji; Horita, Tsuyoshi; Kawase, Chiharu; Oyabu, Isao; Kishimoto, Takeshi.

    1996-01-01

    Mitsubishi Electric has delivered the world's largest DC generator for the toroidal field coil power supply of the JFT-2M Tokamak at the Japan Atomic Energy Research Institute. The unit rotates at 225 or 460 rpm, providing a maximum rated output of 2,700 V, 19,000 A and 51.3 MW. The toroidal field is a DC field, so use of a DC generator permits a simpler design consuming less floor space than an AC drive system. The generator was manufactured following extensive studies on commutation, mechanical strength and insulation. (author)

  12. Does gender affect funding success at the peer-to-peer credit markets? Evidence from the largest German lending platform

    OpenAIRE

    Barasinska, Nataliya; Schäfer, Dorothea

    2010-01-01

    Studies of peer-to-peer lending in the USA find that female borrowers have better chances of getting funds than males. Is differential treatment of borrowers of different sexes a common feature of peer-to-peer lendingmarkets or is it subject to specific businessmodels, ways of fixing loan contracts and even national financial systems? We aim at answering this question by providing evidence on loan procurement at the largest German peer-to-peer lending platform Smava.de. Our results show that ...

  13. Fluctuations in the size of the largest projectile fragment produced in 1 GeV/nucleon Au + C collisions

    International Nuclear Information System (INIS)

    Warren, P.; Elliott, J.B.; Gilkes, M.L.; Hauger, A.; Hirsch, A.S.

    1993-01-01

    Large fluctuations in quantities such as density are characteristic of critical phenomena in the neighborhood of the critical point. Using the EOS apparatus at the Bevalac, we have performed an exclusive experiment in which the size of the largest projectile fragment produced in 1 GeV/nucleon Au+C collisions is studied as a function of the charged multiplicity of the event. A peak in the fluctuations is expected at the critical multiplicity. The data are compared to a percolation model and a statistical multifragmentation model

  14. Global CO_2-energy emissions in 2007. China becomes the largest emitter along with the United States - June 2008

    International Nuclear Information System (INIS)

    2008-01-01

    China becomes the largest emitter along with the United States. Contents: 1990-2007 evolution (key figures of Yearly average evolutions); Global CO_2-energy emissions in 2007: 27,3 GtCO_2; Global CO_2-energy emissions have increased by 3,2% in 2007, largely driven by China. Since 1990, China has more than doubled its CO_2-energy emissions, to reach the same emission level as the USA in 2007. Two very contrasting tendencies appear since 1990: stabilization of emissions in Annex B countries, boom in China and India. Since 1990, more than half of CO_2-energy emissions growth is (logically) due to coal. (authors)

  15. Multidimensional fractionation is a requirement for quantitation of Golgi-resident glycosylation enzymes from cultured human cells.

    Science.gov (United States)

    Lin, Chi-Hung; Chik, Jenny H L; Packer, Nicolle H; Molloy, Mark P

    2015-02-06

    Glycosylation results from the concerted action of glycosylation enzymes in the secretory pathway. In general, gene expression serves as the primary control mechanism, but post-translational fine-tuning of glycosylation enzyme functions is often necessary for efficient synthesis of specific glycan epitopes. While the field of glycomics has rapidly advanced, there lacks routine proteomic methods to measure expression of specific glycosylation enzymes needed to fill the gap between mRNA expression and the glycomic profile in a "reverse genomics" workflow. Toward developing this workflow we enriched Golgi membranes from two human colon cancer cell lines by sucrose density centrifugation and further mass-based fractionation by SDS-PAGE. We then applied mass spectrometry to demonstrate a doubling in the number of Golgi resident proteins identified, compared to the unenriched, low speed centrifuged supernatant of lysed cells. A total of 35 Golgi-resident glycosylation enzymes, of which 23 were glycosyltransferases, were identified making this the largest protein database so far of Golgi resident glycosylation enzymes experimentally identified in cultured human cells. We developed targeted mass spectrometry assays for specific quantitation of many of these glycosylation enzymes. Our results show that alterations in abundance of glycosylation enzymes at the protein level were generally consistent with the resultant glycomic profiles, but not necessarily with the corresponding glycosyltransferase mRNA expression as exemplified by the case of O-glycan core 1 T synthase.

  16. Direct Electron Transfer of Enzymes in a Biologically Assembled Conductive Nanomesh Enzyme Platform.

    Science.gov (United States)

    Lee, Seung-Woo; Lee, Ki-Young; Song, Yong-Won; Choi, Won Kook; Chang, Joonyeon; Yi, Hyunjung

    2016-02-24

    Nondestructive assembly of a nanostructured enzyme platform is developed in combination of the specific biomolecular attraction and electrostatic coupling for highly efficient direct electron transfer (DET) of enzymes with unprecedented applicability and versatility. The biologically assembled conductive nanomesh enzyme platform enables DET-based flexible integrated biosensors and DET of eight different enzyme with various catalytic activities. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Enzyme Activity Experiments Using a Simple Spectrophotometer

    Science.gov (United States)

    Hurlbut, Jeffrey A.; And Others

    1977-01-01

    Experimental procedures for studying enzyme activity using a Spectronic 20 spectrophotometer are described. The experiments demonstrate the effect of pH, temperature, and inhibitors on enzyme activity and allow the determination of Km, Vmax, and Kcat. These procedures are designed for teaching large lower-level biochemistry classes. (MR)

  18. The use of enzymes for beer brewing

    NARCIS (Netherlands)

    Donkelaar, van Laura H.G.; Mostert, Joost; Zisopoulos, Filippos K.; Boom, Remko M.; Goot, van der Atze Jan

    2016-01-01

    The exergetic performance of beer produced by the conventional malting and brewing process is compared with that of beer produced using an enzyme-assisted process. The aim is to estimate if the use of an exogenous enzyme formulation reduces the environmental impact of the overall brewing process.

  19. Lignocellulose biotechnology: issues of bioconversion and enzyme ...

    African Journals Online (AJOL)

    Lignocellulose biotechnology: issues of bioconversion and enzyme production. ... and secondly to highlight some of the modern approaches which potentially could be used to tackle one of the major impediments, namely high enzyme cost, to speed-up the extensive commercialisation of the lignocellulose bioprocessing.

  20. Illustrating Enzyme Inhibition Using Gibbs Energy Profiles

    Science.gov (United States)

    Bearne, Stephen L.

    2012-01-01

    Gibbs energy profiles have great utility as teaching and learning tools because they present students with a visual representation of the energy changes that occur during enzyme catalysis. Unfortunately, most textbooks divorce discussions of traditional kinetic topics, such as enzyme inhibition, from discussions of these same topics in terms of…

  1. Enzyme Catalysis and the Gibbs Energy

    Science.gov (United States)

    Ault, Addison

    2009-01-01

    Gibbs-energy profiles are often introduced during the first semester of organic chemistry, but are less often presented in connection with enzyme-catalyzed reactions. In this article I show how the Gibbs-energy profile corresponds to the characteristic kinetics of a simple enzyme-catalyzed reaction. (Contains 1 figure and 1 note.)

  2. Enzyme Engineering for In Situ Immobilization.

    Science.gov (United States)

    Rehm, Fabian B H; Chen, Shuxiong; Rehm, Bernd H A

    2016-10-14

    Enzymes are used as biocatalysts in a vast range of industrial applications. Immobilization of enzymes to solid supports or their self-assembly into insoluble particles enhances their applicability by strongly improving properties such as stability in changing environments, re-usability and applicability in continuous biocatalytic processes. The possibility of co-immobilizing various functionally related enzymes involved in multistep synthesis, conversion or degradation reactions enables the design of multifunctional biocatalyst with enhanced performance compared to their soluble counterparts. This review provides a brief overview of up-to-date in vitro immobilization strategies while focusing on recent advances in enzyme engineering towards in situ self-assembly into insoluble particles. In situ self-assembly approaches include the bioengineering of bacteria to abundantly form enzymatically active inclusion bodies such as enzyme inclusions or enzyme-coated polyhydroxyalkanoate granules. These one-step production strategies for immobilized enzymes avoid prefabrication of the carrier as well as chemical cross-linking or attachment to a support material while the controlled oriented display strongly enhances the fraction of accessible catalytic sites and hence functional enzymes.

  3. Utilization of enzyme supplemented Telfairia occidentalis stalk ...

    African Journals Online (AJOL)

    An eight (8) week feeding trial was carried out to assess the use of enzyme natuzyme supplemented Telfairia occidentalis stalk extract as growth inducer in the practical diet for Oreochromis niloticus fingerlings. Five isonitrogenous (35% crude protein) diets at 0 ml of stalk extract and enzyme (TRT 1), 15 ml (TRT 2) and 30 ...

  4. Bacterial Enzymes and Antibiotic Resistance- Oral Presentation

    Energy Technology Data Exchange (ETDEWEB)

    Maltz, Lauren [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-25

    By using protein crystallography and X-ray diffraction, structures of bacterial enzymes were solved to gain a better understanding of how enzymatic modification acts as an antibacterial resistance mechanism. Aminoglycoside phosphotransferases (APHs) are one of three aminoglycoside modifying enzymes that confer resistance to the aminoglycoside antibiotics via enzymatic modification, rendering many drugs obsolete. Specifically, the APH(2”) family vary in their substrate specificities and also in their preference for the phosphate donor (ADP versus GDP). By solving the structures of members of the APH(2”) family of enzymes, we can see how domain movements are important to their substrate specificity. Our structure of the ternary complex of APH(2”)-IIIa with GDP and kanamycin, when compared to the known structures of APH(2”)-IVa, reveals that there are real physical differences between these two enzymes, a structural finding that explains why the two enzymes differ in their preferences for certain aminoglycosides. Another important group of bacterial resistance enzymes are the Class D β-lactamases. Oxacillinase carbapenemases (OXAs) are part of this enzyme class and have begun to confer resistance to ‘last resort’ drugs, most notably carbapenems. Our structure of OXA-143 shows that the conformational flexibility of a conserved hydrophobic residue in the active site (Val130) serves to control the entry of a transient water molecule responsible for a key step in the enzyme’s mechanism. Our results provide insight into the structural mechanisms of these two different enzymes.

  5. Application of radiopolymerization for immobilization of enzymes

    International Nuclear Information System (INIS)

    Higa, O.Z.; Mastro, N.L. del; Castagnet, A.C.G.

    1986-01-01

    Hydrophilic glass-forming monomers were used in an application of irradiation technology for the immobilization of cellulase and cellobiase. Experiments to observe the effect of additives such as silicates and polyethylene glycol in the enzyme entrapment are reported on. In all cases, enzymatic activity was maintained for more than fifteen batch enzyme reactions. (Author) [pt

  6. Enzyme-Catalyzed Transetherification of Alkoxysilanes

    Directory of Open Access Journals (Sweden)

    Peter G. Taylor

    2013-01-01

    Full Text Available We report the first evidence of an enzyme-catalyzed transetherification of model alkoxysilanes. During an extensive enzymatic screening in the search for new biocatalysts for silicon-oxygen bond formation, we found that certain enzymes promoted the transetherification of alkoxysilanes when tert-butanol or 1-octanol were used as the reaction solvents.

  7. Enzymes from Higher Eukaryotes for Industrial Biocatalysis

    Directory of Open Access Journals (Sweden)

    Zhibin Liu

    2004-01-01

    Full Text Available The industrial production of fine chemicals, feed and food ingredients, pharmaceuticals, agrochemicals and their respective intermediates relies on an increasing application of biocatalysis, i.e. on enzyme or whole-cell catalyzed conversions of molecules. Simple procedures for discovery, cloning and over-expression as well as fast growth favour fungi, yeasts and especially bacteria as sources of biocatalysts. Higher eukaryotes also harbour an almost unlimited number of potential biocatalysts, although to date the limited supply of enzymes, the high heterogeneity of enzyme preparations and the hazard of infectious contaminants keep some interesting candidates out of reach for industrial bioprocesses. In the past only a few animal and plant enzymes from agricultural waste materials were employed in food processing. The use of bacterial expression strains or non-conventional yeasts for the heterologous production of efficient eukaryotic enzymes can overcome the bottleneck in enzyme supply and provide sufficient amounts of homogenous enzyme preparations for reliable and economically feasible applications at large scale. Ideal enzymatic processes represent an environmentally friendly, »near-to-completion« conversion of (mostly non-natural substrates to pure products. Recent developments demonstrate the commercial feasibility of large-scale biocatalytic processes employing enzymes from higher eukaryotes (e.g. plants, animals and also their usefulness in some small-scale industrial applications.

  8. Biocatalytic material comprising multilayer enzyme coated fiber

    Science.gov (United States)

    Kim, Jungbae [Richland, WA; Kwak, Ja Hun [Richland, WA; Grate, Jay W [West Richland, WA

    2009-11-03

    The present invention relates generally to high stability, high activity biocatalytic materials and processes for using the same. The materials comprise enzyme aggregate coatings having high biocatalytic activity and stability useful in heterogeneous environment. These new materials provide a new biocatalytic immobilized enzyme system with applications in bioconversion, bioremediation, biosensors, and biofuel cells.

  9. 21 CFR 864.4400 - Enzyme preparations.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Enzyme preparations. 864.4400 Section 864.4400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Specimen Preparation Reagents § 864.4400 Enzyme...

  10. Loop 7 of E2 enzymes

    DEFF Research Database (Denmark)

    Papaleo, Elena; Casiraghi, Nicola; Arrigoni, Alberto

    2012-01-01

    The ubiquitin (Ub) system controls almost every aspect of eukaryotic cell biology. Protein ubiquitination depends on the sequential action of three classes of enzymes (E1, E2 and E3). E2 Ub-conjugating enzymes have a central role in the ubiquitination pathway, interacting with both E1 and E3...

  11. Enzyme adsorption at solid-liquid interfaces

    NARCIS (Netherlands)

    Duinhoven, S.

    1992-01-01

    Enzymes are proteins with the capacity of catalysing various reactions. Nowadays two types of enzymes, proteases and lipases, are available for use in detergent formulations for household and industrial laundry washing. Proteases are capable of catalysing the hydrolysis of proteins while

  12. [Potentialization of antibiotics by lytic enzymes].

    Science.gov (United States)

    Brisou, J; Babin, P; Babin, R

    1975-01-01

    Few lytic enzymes, specially papaine and lysozyme, acting on the membrane and cell wall structures facilitate effects of bacitracine, streptomycine and other antibiotics. Streptomycino resistant strains became sensibles to this antibiotic after contact with papaine and lysozyme. The results of tests in physiological suspensions concern only the lytic activity of enzymes. The results on nutrient medium concern together lytic, and antibiotic activities.

  13. Enzyme activity assay of glycoprotein enzymes based on a boronate affinity molecularly imprinted 96-well microplate.

    Science.gov (United States)

    Bi, Xiaodong; Liu, Zhen

    2014-12-16

    Enzyme activity assay is an important method in clinical diagnostics. However, conventional enzyme activity assay suffers from apparent interference from the sample matrix. Herein, we present a new format of enzyme activity assay that can effectively eliminate the effects of the sample matrix. The key is a 96-well microplate modified with molecularly imprinted polymer (MIP) prepared according to a newly proposed method called boronate affinity-based oriented surface imprinting. Alkaline phosphatase (ALP), a glycoprotein enzyme that has been routinely used as an indicator for several diseases in clinical tests, was taken as a representative target enzyme. The prepared MIP exhibited strong affinity toward the template enzyme (with a dissociation constant of 10(-10) M) as well as superb tolerance for interference. Thus, the enzyme molecules in a complicated sample matrix could be specifically captured and cleaned up for enzyme activity assay, which eliminated the interference from the sample matrix. On the other hand, because the boronate affinity MIP could well retain the enzymatic activity of glycoprotein enzymes, the enzyme captured by the MIP was directly used for activity assay. Thus, additional assay time and possible enzyme or activity loss due to an enzyme release step required by other methods were avoided. Assay of ALP in human serum was successfully demonstrated, suggesting a promising prospect of the proposed method in real-world applications.

  14. Distribution of the largest aftershocks in branching models of triggered seismicity: Theory of the universal Baath law

    International Nuclear Information System (INIS)

    Saichev, A.; Sornette, D.

    2005-01-01

    Using the epidemic-type aftershock sequence (ETAS) branching model of triggered seismicity, we apply the formalism of generating probability functions to calculate exactly the average difference between the magnitude of a mainshock and the magnitude of its largest aftershock over all generations. This average magnitude difference is found empirically to be independent of the mainshock magnitude and equal to 1.2, a universal behavior known as Baath's law. Our theory shows that Baath's law holds only sufficiently close to the critical regime of the ETAS branching process. Allowing for error bars ±0.1 for Baath's constant value around 1.2, our exact analytical treatment of Baath's law provides new constraints on the productivity exponent α and the branching ratio n: 0.9 < or approx. α≤1 and 0.8 < or approx. n≤1. We propose a method for measuring α based on the predicted renormalization of the Gutenberg-Richter distribution of the magnitudes of the largest aftershock. We also introduce the 'second Baath law for foreshocks': the probability that a main earthquake turns out to be the foreshock does not depend on its magnitude ρ

  15. The Process of Leadership and the Organizational Knowledge Management: the practicy of the largest industries of Santa Catarina

    Directory of Open Access Journals (Sweden)

    Dante Marciano Girardi

    2012-04-01

    Full Text Available DOI: http://dx.doi.org/10.5007/2175-8077.2012v14n32p65 The aim of this article is to introduce the practices of leadership in the largest industries of Santa Catarina and their contribution to the Knowledge Management. The organization competitiveness is related to the people and to the capacity of the companies to improve the constant development of knowledge. Using the leadership, the managers and the People Management have created compromise and improved the results of the organizations. The adopted methodology followed the qualitative methodology, descriptive and applied research. There were interviewed the seven largest industries of the state of Santa Catarina, in number of collaborators. The data were analyzed by the technique of analysis of content. It has been observed that the leadership is present in the most of the studied companies, by the use of formal programs of development of leaders or of actions related to leadership. It is concluded that the companies have the focus in the people and in the knowledge, in bigger or smaller degree, but some of them are in phase of transition and revision of programs towards the development of their talents and of the Knowledge Management.

  16. Application of the largest Lyapunov exponent and non-linear fractal extrapolation algorithm to short-term load forecasting

    International Nuclear Information System (INIS)

    Wang Jianzhou; Jia Ruiling; Zhao Weigang; Wu Jie; Dong Yao

    2012-01-01

    Highlights: ► The maximal predictive step size is determined by the largest Lyapunov exponent. ► A proper forecasting step size is applied to load demand forecasting. ► The improved approach is validated by the actual load demand data. ► Non-linear fractal extrapolation method is compared with three forecasting models. ► Performance of the models is evaluated by three different error measures. - Abstract: Precise short-term load forecasting (STLF) plays a key role in unit commitment, maintenance and economic dispatch problems. Employing a subjective and arbitrary predictive step size is one of the most important factors causing the low forecasting accuracy. To solve this problem, the largest Lyapunov exponent is adopted to estimate the maximal predictive step size so that the step size in the forecasting is no more than this maximal one. In addition, in this paper a seldom used forecasting model, which is based on the non-linear fractal extrapolation (NLFE) algorithm, is considered to develop the accuracy of predictions. The suitability and superiority of the two solutions are illustrated through an application to real load forecasting using New South Wales electricity load data from the Australian National Electricity Market. Meanwhile, three forecasting models: the gray model, the seasonal autoregressive integrated moving average approach and the support vector machine method, which received high approval in STLF, are selected to compare with the NLFE algorithm. Comparison results also show that the NLFE model is outstanding, effective, practical and feasible.

  17. Enzymic oxidation of carbon monoxide. II

    Energy Technology Data Exchange (ETDEWEB)

    Yagi, T

    1959-01-01

    An enzyme which catalyzes the oxidation of carbon monoxide into carbon dioxide was obtained in a cell free state from Desulfovibrio desulfuricans. The enzyme activity was assayed manometrically by measuring the rate of gas uptake under the atmosphere of carbon monoxide in the presence of benzyl-viologen as an oxidant. The optimum pH range was 7 to 8. The activity was slightly suppressed by illumination. The enzyme was more stable than hydrogenase or formate dehydrogenase against the heat treatment, suggesting that it is a different entity from these enzymes. In the absence of an added oxidant, the enzyme preparation produced hydrogen gas under the atmosphere of carbon monoxide. The phenomenon can be explained assuming the reductive decomposition of water. 17 references, 4 figures, 2 tables.

  18. Enzymes - important players in green chemistry

    Directory of Open Access Journals (Sweden)

    Agata Tarczykowska

    2017-09-01

    Full Text Available Green chemistry has become a worldwide approach that leads to sustainable growth through application and development of its principles. A lot of work has to be put into designing new processes comprising of materials which do not emit pollutants to the atmosphere. Inventing new safer methods and finding less harmful products can be challenging. Enzymes are a great hope of scientists in the field of green chemistry. Enzymes as catalysts require mild conditions therefore it is a great way of saving resources such as energy or water. Processes with the use of enzymes have become more feasible by being more cost effective and eco friendly. Taking into account the benefits of green chemistry, enzyme biocatalysis has quickly replaced traditional chemical processes in several fields, and this substitution is going to reach even more areas because of new emerging technologies in enzyme engineering.

  19. Practical steady-state enzyme kinetics.

    Science.gov (United States)

    Lorsch, Jon R

    2014-01-01

    Enzymes are key components of most biological processes. Characterization of enzymes is therefore frequently required during the study of biological systems. Steady-state kinetics provides a simple and rapid means of assessing the substrate specificity of an enzyme. When combined with site-directed mutagenesis (see Site-Directed Mutagenesis), it can be used to probe the roles of particular amino acids in the enzyme in substrate recognition and catalysis. Effects of interaction partners and posttranslational modifications can also be assessed using steady-state kinetics. This overview explains the general principles of steady-state enzyme kinetics experiments in a practical, rather than theoretical, way. Any biochemistry textbook will have a section on the theory of Michaelis-Menten kinetics, including derivations of the relevant equations. No specific enzymatic assay is described here, although a method for monitoring product formation or substrate consumption over time (an assay) is required to perform the experiments described. © 2014 Elsevier Inc. All rights reserved.

  20. Evaluation of thermostable enzymes for bioethanol processing

    DEFF Research Database (Denmark)

    Skovgaard, Pernille Anastasia

    of fermentable sugars (glucose) as cellulose is tightly linked to hemicellulose and lignin. Lignocellulose is disrupted during pretreatment, but to degrade cellulose to single sugars, lignocellulolytic enzymes such as cellulases and hemicellulases are needed. Lignocellulolytic enzymes are costly...... for the ioethanol production, but the expenses can be reduced by using thermostable enzymes, which are known for their increased stability and inhibitor olerance. However, the advantage of using thermostable enzymes has not been studied thoroughly and more knowledge is needed for development of bioethanol processes....... Enzymes are added to the bioethanol process after pretreatment. For an efficient sugar and ethanol yield, the solids content of biomass is normally increased, which results in highly viscous slurries that are difficult to mix. Therefore, the first enzymatic challenge is to ensure rapid reduction...

  1. Enhanced Oil Recovery with Application of Enzymes

    DEFF Research Database (Denmark)

    Khusainova, Alsu

    Enzymes have recently been reported as effective enhanced oil recovery (EOR) agents. Both laboratory and field tests demonstrated significant increase in the ultimate oil production. Up to16% of additional oil was produced in the laboratory conditions and up to 269 barrels of additional oil per day...... were recovered in the field applications. The following mechanisms were claimed to be responsible for the enhancement of the oil production due to enzymes: wettability improvement of the rock surface; formation of the emulsions; reduction of oil viscosity; and removal of high molecular weight paraffins....... However, the positive effect of enzymes on oil recovery is not that obvious. In most of the studies commercial enzyme products composed of enzymes, surfactants and stabilisers were used. Application of such samples makes it difficult to assign a positive EOR effect to a certain compound, as several...

  2. Fungal enzymes in the attine ant symbiosis

    DEFF Research Database (Denmark)

    de Fine Licht, Henrik Hjarvard; Schiøtt, Morten; Boomsma, Jacobus Jan

    the more basal attine genera use substrates such as flowers, plant debris, small twigs, insect feces and insect carcasses. This diverse array of fungal substrates across the attine lineage implies that the symbiotic fungus needs different enzymes to break down the plant material that the ants provide...... or different efficiencies of enzyme function. Fungal enzymes that degrade plant cell walls may have functionally co-evolved with the ants in this scenario. We explore this hypothesis with direct measurements of enzyme activity in fungus gardens in 12 species across 8 genera spanning the entire phylogeny...... and diversity of life-styles within the attine clade. We find significant differences in enzyme activity between different genera and life-styles of the ants. How these findings relate to attine ant coevolution and crop optimization are discussed....

  3. Production of cellulolytic enzymes from ascomycetes

    DEFF Research Database (Denmark)

    Hansen, Gustav Hammerich; Lübeck, Mette; Frisvad, Jens Christian

    2015-01-01

    Optimizing production of cellulose degrading enzymes is of great interest in order to increase the feasibility of constructing biorefinery facilities for a sustainable supply of energy and chemical products. The ascomycete phylum has a large potential for the production of cellulolytic enzymes....... Although numerous enzymatic profiles have already been unraveled, the research has been covering only a limited number of species and genera, thus leaving many ascomycetes to be analyzed. Such analysis requires choosing appropriate media and cultivation methods that ensure enzyme profiles with high...... specificities and activities. However, the choice of media, cultivation methods and enzyme assays highly affect the enzyme activity profile observed. This review provides an overview of enzymatic profiles for several ascomycetes covering phylogenetically distinct genera and species. The profiles of cellulose...

  4. Enzymes of industrial purpose - review of the market of enzyme preparations and prospects for its development

    Directory of Open Access Journals (Sweden)

    A. A. Tolkacheva

    2017-01-01

    Full Text Available Microbial enzyme preparations are increasingly replacing conventional chemical catalysts in a number of industrial processes. Such drugs, in addition to environmental friendliness and high activity, have a number of advantages over enzyme preparations of vegetable and animal origin, namely: the production of microbial enzymes in bioreactors is easily controlled and predictable; excreted microbiological enzymes are more stable than intracellular animals and plant enzymes; the genetic diversity of microorganisms makes it possible to produce enzyme preparations with a wide range of specificity; microbiological enzymes can be synthesized year-round, in contrast to the production of plant enzymes, which is often seasonal. The leaders of the world market of enzymes are proteases and amylases, which account for 25% and 15%, respectively. Over the past five years, the world market for carbohydrases, including mainly amylases, cellulases and xylanases, has been the fastest growing segment of the enzyme market with an aggregate annual growth rate of more than 7.0%. Another major product of the industrial enzyme market, which has a great potential for growth, is lipases. From the point of view of designation, the main part is represented by food and food enzymes. The Russian market continues to be unsaturated - the current supply is not able to meet the needs of the Russian feed and food industry in enzyme preparations. Enzyme preparations of domestic producers are in demand in forage production, while food industrial enterprises prefer imported products. The most significant enterprises in the enzymatic industry in Russia at the moment are Sibbiofarm, AgroSistema, Agroferment. In the light of the Russian policy of increasing food security, the development of the domestic enzyme industry is an extremely topical task.

  5. Expanding the Halohydrin Dehalogenase Enzyme Family: Identification of Novel Enzymes by Database Mining.

    Science.gov (United States)

    Schallmey, Marcus; Koopmeiners, Julia; Wells, Elizabeth; Wardenga, Rainer; Schallmey, Anett

    2014-12-01

    Halohydrin dehalogenases are very rare enzymes that are naturally involved in the mineralization of halogenated xenobiotics. Due to their catalytic potential and promiscuity, many biocatalytic reactions have been described that have led to several interesting and industrially important applications. Nevertheless, only a few of these enzymes have been made available through recombinant techniques; hence, it is of general interest to expand the repertoire of these enzymes so as to enable novel biocatalytic applications. After the identification of specific sequence motifs, 37 novel enzyme sequences were readily identified in public sequence databases. All enzymes that could be heterologously expressed also catalyzed typical halohydrin dehalogenase reactions. Phylogenetic inference for enzymes of the halohydrin dehalogenase enzyme family confirmed that all enzymes form a distinct monophyletic clade within the short-chain dehydrogenase/reductase superfamily. In addition, the majority of novel enzymes are substantially different from previously known phylogenetic subtypes. Consequently, four additional phylogenetic subtypes were defined, greatly expanding the halohydrin dehalogenase enzyme family. We show that the enormous wealth of environmental and genome sequences present in public databases can be tapped for in silico identification of very rare but biotechnologically important biocatalysts. Our findings help to readily identify halohydrin dehalogenases in ever-growing sequence databases and, as a consequence, make even more members of this interesting enzyme family available to the scientific and industrial community. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  6. An overview of technologies for immobilization of enzymes and surface analysis techniques for immobilized enzymes

    Science.gov (United States)

    Mohamad, Nur Royhaila; Marzuki, Nur Haziqah Che; Buang, Nor Aziah; Huyop, Fahrul; Wahab, Roswanira Abdul

    2015-01-01

    The current demands of sustainable green methodologies have increased the use of enzymatic technology in industrial processes. Employment of enzyme as biocatalysts offers the benefits of mild reaction conditions, biodegradability and catalytic efficiency. The harsh conditions of industrial processes, however, increase propensity of enzyme destabilization, shortening their industrial lifespan. Consequently, the technology of enzyme immobilization provides an effective means to circumvent these concerns by enhancing enzyme catalytic properties and also simplify downstream processing and improve operational stability. There are several techniques used to immobilize the enzymes onto supports which range from reversible physical adsorption and ionic linkages, to the irreversible stable covalent bonds. Such techniques produce immobilized enzymes of varying stability due to changes in the surface microenvironment and degree of multipoint attachment. Hence, it is mandatory to obtain information about the structure of the enzyme protein following interaction with the support surface as well as interactions of the enzymes with other proteins. Characterization technologies at the nanoscale level to study enzymes immobilized on surfaces are crucial to obtain valuable qualitative and quantitative information, including morphological visualization of the immobilized enzymes. These technologies are pertinent to assess efficacy of an immobilization technique and development of future enzyme immobilization strategies. PMID:26019635

  7. Metagenomics as a Tool for Enzyme Discovery: Hydrolytic Enzymes from Marine-Related Metagenomes.

    Science.gov (United States)

    Popovic, Ana; Tchigvintsev, Anatoly; Tran, Hai; Chernikova, Tatyana N; Golyshina, Olga V; Yakimov, Michail M; Golyshin, Peter N; Yakunin, Alexander F

    2015-01-01

    This chapter discusses metagenomics and its application for enzyme discovery, with a focus on hydrolytic enzymes from marine metagenomic libraries. With less than one percent of culturable microorganisms in the environment, metagenomics, or the collective study of community genetics, has opened up a rich pool of uncharacterized metabolic pathways, enzymes, and adaptations. This great untapped pool of genes provides the particularly exciting potential to mine for new biochemical activities or novel enzymes with activities tailored to peculiar sets of environmental conditions. Metagenomes also represent a huge reservoir of novel enzymes for applications in biocatalysis, biofuels, and bioremediation. Here we present the results of enzyme discovery for four enzyme activities, of particular industrial or environmental interest, including esterase/lipase, glycosyl hydrolase, protease and dehalogenase.

  8. Assessment of bioaerosol contamination (bacteria and fungi) in the largest urban wastewater treatment plant in the Middle East.

    Science.gov (United States)

    Niazi, Sadegh; Hassanvand, Mohammad Sadegh; Mahvi, Amir Hossein; Nabizadeh, Ramin; Alimohammadi, Mahmood; Nabavi, Samira; Faridi, Sasan; Dehghani, Asghar; Hoseini, Mohammad; Moradi-Joo, Mohammad; Mokamel, Adel; Kashani, Homa; Yarali, Navid; Yunesian, Masud

    2015-10-01

    Bioaerosol concentration was measured in wastewater treatment units in south of Tehran, the largest wastewater treatment plant in the Middle East. Active sampling was carried out around four operational units and a point as background. The results showed that the aeration tank with an average of 1016 CFU/m(3) in winter and 1973 CFU/m(3) in summer had the greatest effect on emission of bacterial bioaerosols. In addition, primary treatment had the highest impact on fungal emission. Among the bacteria, Micrococcus spp. showed the widest emission in the winter, and Bacillus spp. was dominant in summer. Furthermore, fungi such as Penicillium spp. and Cladosporium spp. were the dominant types in the seasons. Overall, significant relationship was observed between meteorological parameters and the concentration of bacterial and fungal aerosols.

  9. Spatial Air Index Based on Largest Empty Rectangles for Non-Flat Wireless Broadcast in Pervasive Computing

    Directory of Open Access Journals (Sweden)

    Jun-Hong Shen

    2016-11-01

    Full Text Available In pervasive computing, location-based services (LBSs are valuable for mobile clients based on their current locations. LBSs use spatial window queries to enable useful applications for mobile clients. Based on skewed access patterns of mobile clients, non-flat wireless broadcast has been shown to efficiently disseminate spatial objects to mobile clients. In this paper, we consider a scenario in which spatial objects are broadcast to mobile clients over a wireless channel in a non-flat broadcast manner to process window queries. For such a scenario, we propose an efficient spatial air index method to handle window query access in non-flat wireless broadcast environments. The concept of largest empty rectangles is used to avoid unnecessary examination of the broadcast content, thus reducing the processing time for window queries. Simulation results show that the proposed spatial air index method outperforms the existing methods under various settings.

  10. An Examination of Strategic Philanthropy and CSR Communication Patterns among the World’s Twenty-One Largest Oil Companies

    Directory of Open Access Journals (Sweden)

    J. Brad Gatlin

    2013-07-01

    Full Text Available Fortune Magazine’s 2012 list of 100 largest companies included 21 oil companies. This paper seeks to discern patterns of those 21 companies’ philanthropic efforts and communication thereof. Specifically, the paper will consider issues such as ownership (all companies were either publicly-traded or state-owned, the economic development of the home country, and the citizens’ expectations of corporate citizens. The philanthropic efforts of all 21 companies are discussed in the context of Porter and Kramer’s (2001 framework of the competitive context It is concluded that the oil industry is particularly well-suited to affect factor and, to a lesser extent, demand conditions, through philanthropic efforts. A model for classifying the philanthropic based on ownership and country conditions is proposed, and suggestions for further research are made.

  11. The Curse of the Gold: Discourses Surrounding the Project of the Largest Pit-mine in Europe

    Directory of Open Access Journals (Sweden)

    Istvan Egresi

    2011-11-01

    Full Text Available In 1996, a Canadian company started geological explorations in the Rosia Montana area in the Romanian Carpathians. Two years later it formed a joint-venture with a Romanian state company to exploit what is believed to be Europe´s largest gold reserves. However, as of June 2011 extraction has not started yet and it may never start due to the opposition of numerous NGO´s that have pointed out the environmental, social and economic unsustainability of this mining project. This situation is highly unusual for a country that is hungry for foreign investment especially since up until very recently the state had supported any project promising to revitalize its mining sector. This paper will investigate the changes in the discourses surrounding this mining project taking into consideration the effects of globalization and the effects of Romania´s EU membership after 2007.

  12. Causes and Consequences of Ownership Concentration among Europe´s Largest Companies: Economic and Systemic Explanations

    DEFF Research Database (Denmark)

    Pedersen, Torben; Thomsen, Steen

    1999-01-01

    The paper examines causes and effects of ownership concentration among the largest companies in 12 European countries. As a reference point the paper takes a seminal empirical study on US data by Demsetz and Lehn (1985) and examines to what extent their model is applicable in European countries....... The findings indicate that both general economic effects and system effects are significant. Ownership concentration is found to decrease with firm size and to increase with earnings volatility. But in support of the system theories advocated by Roe (1991), Laporta et al. (1996) and Shleifer and Vishny (1997......) nationality is also found to have a significant effect which is partly attributable to institutional differences between nations such as stock market size and the frequency of large banks. Finally, in line with Demsetz and Lehn (1985), ownership concentration is found to have an insignificant effect...

  13. Immobilized enzyme studies in a microscale bioreactor.

    Science.gov (United States)

    Jones, Francis; Forrest, Scott; Palmer, Jim; Lu, Zonghuan; Elmore, John; Elmore, Bill B

    2004-01-01

    Novel microreactors with immobilized enzymes were fabricated using both silicon and polymer-based microfabrication techniques. The effectiveness of these reactors was examined along with their behavior over time. Urease enzyme was successfully incorporated into microchannels of a polymeric matrix of polydimethylsiloxane and through layer-bylayer self-assembly techniques onto silicon. The fabricated microchannels had cross-sectional dimensions ranging from tens to hundreds of micrometers in width and height. The experimental results for continuous-flow microreactors are reported for the conversion of urea to ammonia by urease enzyme. Urea conversions of >90% were observed.

  14. Enzyme-based antifouling coatings: a review

    DEFF Research Database (Denmark)

    Olsen, Stefan Møller; Pedersen, Leif Toudal; Laursen, M.H.

    2007-01-01

    A systematic overview is presented of the literature that reports the antifouling (AF) protection of underwater structures via the action of enzymes. The overall aim of this review is to assess the state of the art of enzymatic AF technology, and to highlight the obstacles that have to be overcome...... for successful development of enzymatic AF coatings. The approaches described in the literature are divided into direct and indirect enzymatic AF, depending on the intended action of the enzymes. Direct antifouling is used when the enzymes themselves are active antifoulants. Indirect antifouling refers...

  15. Enzymic hydrolysis of cellulosic wastes to glucose

    Energy Technology Data Exchange (ETDEWEB)

    Spano, L A; Medeiros, J; Mandels, M

    1976-01-01

    An enzymic process for the conversion of cellulose to glucose is based on the use of a specific enzyme derived from mutant strains of the fungus trichoderma viride which is capable of reacting with the crystalline fraction of the cellulose molecule. The production and mode of action of the cellulase complex produced during the growth of trichoderma viride is discussed as well as the application of such enzymes for the conversion of cellulosic wastes to crude glucose syrup for use in production of chemical feedstocks, single-cell proteins, fuels, solvents, etc.

  16. Dibromine radical anion reactions with heme enzymes

    International Nuclear Information System (INIS)

    Gebicka, L.; Gebicki, J.L.

    1996-01-01

    Reactions of Br 2 radical anion with heme enzymes, catalase horseradish peroxidase, have been studied by pulse radiolysis. It has been found that Br 2 - does not react with the heme centre of investigated enzymes. Dibromine radical anion reacts with tryptophan residues of catalase without any influence on the activity of catalase. It is suggested that in pulse radiolysis studies, where horseradish peroxidase is at about tenfold excess toward Br 2 - , the enzyme is modified rather by Br 2 , than by Br 2 - . (author). 26 refs., 3 figs

  17. Dimeric assembly of enterocyte brush border enzymes

    DEFF Research Database (Denmark)

    Danielsen, E M

    1994-01-01

    The noncovalent, dimeric assembly of small intestinal brush border enzymes was studied by sedimentation analysis in density gradients of extracts of pulse-labeled pig jejunal mucosal explants. Like aminopeptidase N (EC 3.4.11.2), sucrase-isomaltase (EC 3.2.1.48-10), aminopeptidase A (EC 3...... appearance of the liposome-reconstituted enzyme [Norén et al. (1986) J. Biol. Chem. 261, 12306-12309], showing only the inner, membrane-anchored domains of the monomers to be in close contact with one another while the outer domains are far apart. In contrast to the other brush border enzymes studied...

  18. Draft sequencing and assembly of the genome of the world's largest fish, the whale shark: Rhincodon typus Smith 1828.

    Science.gov (United States)

    Read, Timothy D; Petit, Robert A; Joseph, Sandeep J; Alam, Md Tauqeer; Weil, M Ryan; Ahmad, Maida; Bhimani, Ravila; Vuong, Jocelyn S; Haase, Chad P; Webb, D Harry; Tan, Milton; Dove, Alistair D M

    2017-07-14

    The whale shark (Rhincodon typus) has by far the largest body size of any elasmobranch (shark or ray) species. Therefore, it is also the largest extant species of the paraphyletic assemblage commonly referred to as fishes. As both a phenotypic extreme and a member of the group Chondrichthyes - the sister group to the remaining gnathostomes, which includes all tetrapods and therefore also humans - its genome is of substantial comparative interest. Whale sharks are also listed as an endangered species on the International Union for Conservation of Nature's Red List of threatened species and are of growing popularity as both a target of ecotourism and as a charismatic conservation ambassador for the pelagic ecosystem. A genome map for this species would aid in defining effective conservation units and understanding global population structure. We characterised the nuclear genome of the whale shark using next generation sequencing (454, Illumina) and de novo assembly and annotation methods, based on material collected from the Georgia Aquarium. The data set consisted of 878,654,233 reads, which yielded a draft assembly of 1,213,200 contigs and 997,976 scaffolds. The estimated genome size was 3.44Gb. As expected, the proteome of the whale shark was most closely related to the only other complete genome of a cartilaginous fish, the holocephalan elephant shark. The whale shark contained a novel Toll-like-receptor (TLR) protein with sequence similarity to both the TLR4 and TLR13 proteins of mammals and TLR21 of teleosts. The data are publicly available on GenBank, FigShare, and from the NCBI Short Read Archive under accession number SRP044374. This represents the first shotgun elasmobranch genome and will aid studies of molecular systematics, biogeography, genetic differentiation, and conservation genetics in this and other shark species, as well as providing comparative data for studies of evolutionary biology and immunology across the jawed vertebrate lineages.

  19. Process for preparing multilayer enzyme coating on a fiber

    Science.gov (United States)

    Kim, Jungbae [Richland, WA; Kwak, Ja Hun [Richland, WA; Grate, Jay W [West Richland, WA

    2009-11-03

    A process for preparing high stability, high activity biocatalytic materials is disclosed and processes for using the same. The process involves coating of a material or fiber with enzymes and enzyme aggregate providing a material or fiber with high biocatalytic activity and stability useful in heterogeneous environments. In one illustrative approach, enzyme "seeds" are covalently attached to polymer nanofibers followed by treatment with a reagent that crosslinks additional enzyme molecules to the seed enzymes forming enzyme aggregates thereby improving biocatalytic activity due to increased enzyme loading and enzyme stability. This approach creates a useful new biocatalytic immobilized enzyme system with potential applications in bioconversion, bioremediation, biosensors, and biofuel cells.

  20. Dietary modulation of thymic enzymes.

    Science.gov (United States)

    Susana, Feliu María; Paula, Perris; Slobodianik, Nora

    2014-01-01

    Malnutrition is a complex syndrome caused by an inadequate intake of energy, protein, minerals and vitamins which affects the immune system. Nutritional imbalances, present in children with energy-protein malnutrition and infections, make defining the specific effects of each of them on the thymus difficult. For this reason, it is necessary to design an experimental model in animals that could define a single variable. As the thymus atrophy described in humans is similar to that observed in murines, a rat experimental model makes the extrapolation to man possible. Some authors suggest that the activity of Adenosine Deaminase (ADA) and Purine Nucleoside Phosphorylase (PNP)--involved in purine metabolism--have an influence on T lymphocyte development and the immune system, due to intracellular accumulation of toxic levels of deoxynucleotides. Studies in our group, performed in an experimental model on Wistar growing rats, have demonstrated that protein deficiency or imbalance in the profile of essential amino acids in the diet, produce loss of thymus weight, reduction in the number of thymocytes, a diminished proportion of T cells presenting the W3/13 antigenic determinant and DNA content with concomitant increase in cell size, and the proportion of immature T cells and activity of ADA and PNP, without modifying the activity of 5´Nucleotidase in the thymus. It is important to point out that there were neither differences in energy intake between experimental groups and their controls, nor clinical symptoms of deficiency of other nutrients. The increase in these thymic enzyme activities was an alternative mechanism to avoid the accumulation of high levels of deoxynucleotides, which would be toxic for T lymphocytes. On the other hand, the administration of a recovery diet, with a high amount of high quality protein, was able to reverse the mentioned effects. The quick reply of Adenosine Deaminase to nutritional disorders and the following nutritional recovery, points

  1. Direct Comparison of the Enzymatic Characteristics and Superoxide Production of the Four Aldehyde Oxidase Enzymes Present in Mouse.

    Science.gov (United States)

    Kücükgöze, Gökhan; Terao, Mineko; Garattini, Enrico; Leimkühler, Silke

    2017-08-01

    Aldehyde oxidases (AOXs) are molybdoflavoenzymes with an important role in the metabolism and detoxification of heterocyclic compounds and aliphatic as well as aromatic aldehydes. The enzymes use oxygen as the terminal electron acceptor and produce reduced oxygen species during turnover. Four different enzymes, mAOX1, mAOX3, mAOX4, and mAOX2, which are the products of distinct genes, are present in the mouse. A direct and simultaneous comparison of the enzymatic properties and characteristics of the four enzymes has never been performed. In this report, the four catalytically active mAOX enzymes were purified after heterologous expression in Escherichia coli The kinetic parameters of the four mouse AOX enzymes were determined and compared with the use of six predicted substrates of physiologic and toxicological interest, i.e., retinaldehyde, N 1 -methylnicotinamide, pyridoxal, vanillin, 4-(dimethylamino)cinnamaldehyde ( p- DMAC), and salicylaldehyde. While retinaldehyde, vanillin, p- DMAC, and salycilaldehyde are efficient substrates for the four mouse AOX enzymes, N 1 -methylnicotinamide is not a substrate of mAOX1 or mAOX4, and pyridoxal is not metabolized by any of the purified enzymes. Overall, mAOX1, mAOX2, mAOX3, and mAOX4 are characterized by significantly different K M and k cat values for the active substrates. The four mouse AOXs are also characterized by quantitative differences in their ability to produce superoxide radicals. With respect to this last point, mAOX2 is the enzyme generating the largest rate of superoxide radicals of around 40% in relation to moles of substrate converted, and mAOX1, the homolog to the human enzyme, produces a rate of approximately 30% of superoxide radicals with the same substrate. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

  2. Highly efficient enzyme encapsulation in a protein nanocage: towards enzyme catalysis in a cellular nanocompartment mimic

    Science.gov (United States)

    Schoonen, Lise; Nolte, Roeland J. M.; van Hest, Jan C. M.

    2016-07-01

    The study of enzyme behavior in small nanocompartments is crucial for the understanding of biocatalytic processes in the cellular environment. We have developed an enzymatic conjugation strategy to attach a model enzyme to the interior of a cowpea chlorotic mottle virus capsid. It is shown that with this methodology high encapsulation efficiencies can be achieved. Additionally, we demonstrate that the encapsulation does not affect the enzyme performance in terms of a decreased activity or a hampered substrate diffusion. Finally, it is shown that the encapsulated enzymes are protected against proteases. We believe that our strategy can be used to study enzyme kinetics in an environment that approaches physiological conditions.The study of enzyme behavior in small nanocompartments is crucial for the understanding of biocatalytic processes in the cellular environment. We have developed an enzymatic conjugation strategy to attach a model enzyme to the interior of a cowpea chlorotic mottle virus capsid. It is shown that with this methodology high encapsulation efficiencies can be achieved. Additionally, we demonstrate that the encapsulation does not affect the enzyme performance in terms of a decreased activity or a hampered substrate diffusion. Finally, it is shown that the encapsulated enzymes are protected against proteases. We believe that our strategy can be used to study enzyme kinetics in an environment that approaches physiological conditions. Electronic supplementary information (ESI) available: Experimental procedures for the cloning, expression, and purification of all proteins, as well as supplementary figures and calculations. See DOI: 10.1039/c6nr04181g

  3. Impact of enzyme loading on the efficacy and recovery of cellulolytic enzymes immobilized on enzymogel nanoparticles.

    Science.gov (United States)

    Samaratunga, Ashani; Kudina, Olena; Nahar, Nurun; Zakharchenko, Andrey; Minko, Sergiy; Voronov, Andriy; Pryor, Scott W

    2015-03-01

    Cellulase and β-glucosidase were adsorbed on a polyacrylic acid polymer brush grafted on silica nanoparticles to produce enzymogels as a form of enzyme immobilization. Enzyme loading on the enzymogels was increased to a saturation level of approximately 110 μg (protein) mg(-1) (particle) for each enzyme. Enzymogels with varied enzyme loadings were then used to determine the impact on hydrolysis rate and enzyme recovery. Soluble sugar concentrations during the hydrolysis of filter paper and Solka-Floc with the enzymogels were 45 and 53%, respectively, of concentrations when using free cellulase. β-Glucosidase enzymogels showed lower performance; hydrolyzate glucose concentrations were just 38% of those using free enzymes. Increasing enzyme loading on the enzymogels did not reduce net efficacy for cellulase and improved efficacy for β-glucosidase. The use of free cellulases and cellulase enzymogels resulted in hydrolyzates with different proportions of cellobiose and glucose, suggesting differential attachment or efficacy of endoglucanases, exoglucanases, and β-glucosidases present in cellulase mixtures. When loading β-glucosidase individually, higher enzyme loadings on the enzymogels produced higher hydrolyzate glucose concentrations. Approximately 96% of cellulase and 66 % of β-glucosidase were recovered on the enzymogels, while enzyme loading level did not impact recovery for either enzyme.

  4. Role of antioxidant scavenging enzymes and extracellular ...

    African Journals Online (AJOL)

    ChithrashreeGS

    2012-08-23

    Aug 23, 2012 ... peroxidase are two important antioxidant scavenging enzymes involved in ... Catalase was assayed using the method of Beers and Sizer. (1951) with .... yeast dextrose calcium carbonate agar (YDC) medium. Catalase and ...

  5. Involvement of methyltransferases enzymes during the energy

    African Journals Online (AJOL)

    Mgina

    INVOLVEMENT OF METHYLTRANSFERASES ENZYMES DURING THE. ENERGY METABOLISM OF ..... cell extract still exhibited relatively high methanogenesis with methanol (Fig ... product CH3-CoM into methane (see Fig. 1). The HS-CoM ...

  6. Enzymes: The possibility of production and applications

    Directory of Open Access Journals (Sweden)

    Petronijević Živomir B.

    2003-01-01

    Full Text Available Enzymes are biological catalysts with increasing application in the food pharmaceutical, cosmetic, textile and chemical industry. They are also important as reagents in chemical analysis, leather fabrications and as targets for the design of new drugs. Keeping in mind the growing need to replace classical chemical processes by alternative ones, because of ever growing environmental pollution, it is important that enzyme and other biotechnological processes are economical. Therefore, price decrease and stability and enzyme preparation efficiency increase are required more and more. This paper presents a short review of methods for yield increase and the improvement of the quality of enzyme products as commercial products, as well as a review of the possibilities of their application.

  7. Optimizing culture medium for debittering constitutive enzyme ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-08-02

    Aug 2, 2010 ... enzyme naringinase production by Aspergillus oryzae. JMU316. Dong-xiao .... even though industrial applications of naringinase are becoming more and ... guidance for industry. MATERIALS AND ..... For economic reasons,.

  8. distribution, abundance and properties of restriction enzymes

    African Journals Online (AJOL)

    DNA of granule-bound starch synthase (GBSS) I and II with a view to ... properties for manipulation of the genes for production of modified starch. .... procurement, storage and handling of the ..... been made on restriction enzymes of potato,.

  9. Novel enzymes for the degradation of cellulose

    Directory of Open Access Journals (Sweden)

    Horn Svein

    2012-07-01

    Full Text Available Abstract The bulk terrestrial biomass resource in a future bio-economy will be lignocellulosic biomass, which is recalcitrant and challenging to process. Enzymatic conversion of polysaccharides in the lignocellulosic biomass will be a key technology in future biorefineries and this technology is currently the subject of intensive research. We describe recent developments in enzyme technology for conversion of cellulose, the most abundant, homogeneous and recalcitrant polysaccharide in lignocellulosic biomass. In particular, we focus on a recently discovered new type of enzymes currently classified as CBM33 and GH61 that catalyze oxidative cleavage of polysaccharides. These enzymes promote the efficiency of classical hydrolytic enzymes (cellulases by acting on the surfaces of the insoluble substrate, where they introduce chain breaks in the polysaccharide chains, without the need of first “extracting” these chains from their crystalline matrix.

  10. Enzymes in Poultry and Swine Nutrition

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

    Poultry production in China and the potential for using enzyme preparations .... The feed manufacturers produce about 310 × 106t of high-quality feed, saving about 30%, ...... Chickens and experimental designs used in the three experiments.

  11. Archaeal Enzymes and Applications in Industrial Biocatalysts.

    Science.gov (United States)

    Littlechild, Jennifer A

    2015-01-01

    Archaeal enzymes are playing an important role in industrial biotechnology. Many representatives of organisms living in "extreme" conditions, the so-called Extremophiles, belong to the archaeal kingdom of life. This paper will review studies carried by the Exeter group and others regarding archaeal enzymes that have important applications in commercial biocatalysis. Some of these biocatalysts are already being used in large scale industrial processes for the production of optically pure drug intermediates and amino acids and their analogues. Other enzymes have been characterised at laboratory scale regarding their substrate specificity and properties for potential industrial application. The increasing availability of DNA sequences from new archaeal species and metagenomes will provide a continuing resource to identify new enzymes of commercial interest using both bioinformatics and screening approaches.

  12. Polyphenol Oxidase Enzyme and Inactivation Methods

    Directory of Open Access Journals (Sweden)

    Leman Yılmaz

    2018-03-01

    Full Text Available Polyphenol oxidase enzyme is found in vegetables and fruits, as well as in some animal organs and microorganisms. Polyphenol oxidase enzyme responsible for enzymatic browning is a group of copper proteins that catalyses the oxidation of phenolic compounds to quinones, which produce brown pigments, commonly found in fruits and vegetables. During the industrial preparation of fruits and vegetables, results of catalytic effect of polyphenol oxidase causes enzymatic browning. Enzymatic browning impairs the appearance of products containing phenolic compounds along with undesirable colour, odor and taste formation and significant loss of nutritional value of the products. This affects the acceptability of the products by the consumers and causes economic losses. In this review, some characteristics of polyphenol oxidase enzyme in different fruits and vegetables have been reviewed and information about chemical antibrowning agents, thermal applications, irradiation applications and alternative methods such as high pressure processing, pulse electric field, supercritical carbon dioxide and ultrasound applications to inactivate this enzyme has been presented.

  13. Radioimmunoassay of polypeptide hormones and enzymes

    International Nuclear Information System (INIS)

    Felber, J.P.

    1974-01-01

    General principles of radioimmunoassay are reviewed. Detailed procedures are reviewed for the following hormones: insulin, pituitary hormones, gonadotropins, parathyroid hormone, ACTH, glucagon, gastrin, and peptide hormones. Radioimmunoassay of enzymes is also discussed. (U.S.)

  14. Extracellular enzyme kinetics scale with resource availability

    Science.gov (United States)

    Sinsabaugh, Robert L.; Belnap, Jayne; Findlay, Stuart G.; Follstad Shah, Jennifer J.; Hill, Brian H.; Kuehn, Kevin A.; Kuske, Cheryl; Litvak, Marcy E.; Martinez, Noelle G.; Moorhead, Daryl L.; Warnock, Daniel D.

    2014-01-01

    Microbial community metabolism relies on external digestion, mediated by extracellular enzymes that break down complex organic matter into molecules small enough for cells to assimilate. We analyzed the kinetics of 40 extracellular enzymes that mediate the degradation and assimilation of carbon, nitrogen and phosphorus by diverse aquatic and terrestrial microbial communities (1160 cases). Regression analyses were conducted by habitat (aquatic and terrestrial), enzyme class (hydrolases and oxidoreductases) and assay methodology (low affinity and high affinity substrates) to relate potential reaction rates to substrate availability. Across enzyme classes and habitats, the scaling relationships between apparent Vmax and apparent Km followed similar power laws with exponents of 0.44 to 0.67. These exponents, called elasticities, were not statistically distinct from a central value of 0.50, which occurs when the Km of an enzyme equals substrate concentration, a condition optimal for maintenance of steady state. We also conducted an ecosystem scale analysis of ten extracellular hydrolase activities in relation to soil and sediment organic carbon (2,000–5,000 cases/enzyme) that yielded elasticities near 1.0 (0.9 ± 0.2, n = 36). At the metabolomic scale, the elasticity of extracellular enzymatic reactions is the proportionality constant that connects the C:N:P stoichiometries of organic matter and ecoenzymatic activities. At the ecosystem scale, the elasticity of extracellular enzymatic reactions shows that organic matter ultimately limits effective enzyme binding sites. Our findings suggest that one mechanism by which microbial communities maintain homeostasis is regulating extracellular enzyme expression to optimize the short-term responsiveness of substrate acquisition. The analyses also show that, like elemental stoichiometry, the fundamental attributes of enzymatic reactions can be extrapolated from biochemical to community and ecosystem scales.

  15. Purification and characterization of protease enzyme from ...

    African Journals Online (AJOL)

    The enzyme was active in pH range 5 to11 and temperature of 30 to 80°C. The optimum pH and the temperature for protease activity were recorded to be pH 8 and 50°C, respectively. The enzyme was stable up to 40°C and pH 9. The protease activity was inhibited by Zn2+, Ni2+ and Sn2+ and increased by Ca2+, Mg2+ ...

  16. Enzyme-driven mechanisms in biocorrosion

    OpenAIRE

    Basséguy, Régine

    2007-01-01

    Objectives (abstract of presentation): Recent works carried out in our team concerning enzymes and biocorrosion are presented at the meeting. For aerobic conditions, the direct catalysis of the reduction of oxygen on steel by enzymes or porphyrin was proved and a local electrochemical analysis technique (SVET) was developed to visualize the localization of the catalysis. On anaerobic conditions, the influence of phosphate species and other weak acids on the water reduction on steel was shown....

  17. A stochastic model of enzyme kinetics

    Science.gov (United States)

    Stefanini, Marianne; Newman, Timothy; McKane, Alan

    2003-10-01

    Enzyme kinetics is generally modeled by deterministic rate equations, and in the simplest case leads to the well-known Michaelis-Menten equation. It is plausible that stochastic effects will play an important role at low enzyme concentrations. We have addressed this by constructing a simple stochastic model which can be exactly solved in the steady-state. Throughout a wide range of parameter values Michaelis-Menten dynamics is replaced by a new and simple theoretical result.

  18. Enzyme Technology for Shipboard Waste Management

    Science.gov (United States)

    1976-12-01

    sucrose to the sweeter invert sugar by the enzyme invertase is a well established process, as is the conversion of starch to glucose by the enzyme...aspects of our health and daily lives. Recent advances in fundamental and applied enzymology indicate that we have already started in that direction. At a...Chemtech, p. 677 (Nov 1973) 11 - Bungay, H. P., "Applied Enzymology ," Worthington, Biochemical Corp., Notes for an AIChE Lecture, Washington, D. C. (Dec

  19. Metatranscriptomics Reveals the Functions and Enzyme Profiles of the Microbial Community in Chinese Nong-Flavor Liquor Starter

    Directory of Open Access Journals (Sweden)

    Yuhong Huang

    2017-09-01

    Full Text Available Chinese liquor is one of the world's best-known distilled spirits and is the largest spirit category by sales. The unique and traditional solid-state fermentation technology used to produce Chinese liquor has been in continuous use for several thousand years. The diverse and dynamic microbial community in a liquor starter is the main contributor to liquor brewing. However, little is known about the ecological distribution and functional importance of these community members. In this study, metatranscriptomics was used to comprehensively explore the active microbial community members and key transcripts with significant functions in the liquor starter production process. Fungi were found to be the most abundant and active community members. A total of 932 carbohydrate-active enzymes, including highly expressed auxiliary activity family 9 and 10 proteins, were identified at 62°C under aerobic conditions. Some potential thermostable enzymes were identified at 50, 62, and 25°C (mature stage. Increased content and overexpressed key enzymes involved in glycolysis and starch, pyruvate and ethanol metabolism were detected at 50 and 62°C. The key enzymes of the citrate cycle were up-regulated at 62°C, and their abundant derivatives are crucial for flavor generation. Here, the metabolism and functional enzymes of the active microbial communities in NF liquor starter were studied, which could pave the way to initiate improvements in liquor quality and to discover microbes that produce novel enzymes or high-value added products.

  20. Visualization of enzyme activities inside earthworm pores

    Science.gov (United States)

    Hoang, Duyen; Razavi, Bahar S.

    2015-04-01

    In extremely dynamic microhabitats as bio-pores made by earthworm, the in situ enzyme activities are assumed as a footprint of complex biotic interactions. Our study focused on the effect of earthworm on the enzyme activities inside bio-pores and visualizing the differences between bio-pores and earthworm-free soil by zymography technique (Spohn and Kuzyakov, 2013). For the first time, we aimed at quantitative imaging of enzyme activities in bio-pores. Lumbricus terrestris L. was placed into transparent box (15×20×15cm). After two weeks when bio-pore systems were formed by earthworms, we visualized in situ enzyme activities of five hydrolytic enzymes (β-glucosidase, cellobiohydrolase, chitinase, xylanase, leucine-aminopeptidase, and phosphatase. Zymography showed higher activity of β-glucosidase, chitinase, xylanase and phosphatase in biopores comparing to bulk soil. However, the differences in activity of cellobiohydrolase and leucine aminopeptidase between bio-pore and bulk soil were less pronounced. This demonstrated an applicability of zymography approach to monitor and to distinguish the in situ activity of hydrolytic enzymes in soil biopores.

  1. The ultrasound technology for modifying enzyme activity

    Directory of Open Access Journals (Sweden)

    Meliza Lindsay Rojas

    2016-01-01

    Full Text Available Enzymes are protein complexes compounds widely studied and used due to their ability to catalyze reactions. The food processing mainly a ims the inactivation of enzymes due to various undesirable effects. However, there are many processes that can be optimized by its catalytic activity. In this context, different technologies have been applied both to inactivate or to improve the enzymes ef ficiency. The Ultrasound technology emerges as an alternative mainly applied to achieve the enzyme inactivation. On the contrary, very few investigations show the ability of this technology under certain conditions to achieve the opposite effect (i.e. increase the catalytic activity of enzymes. The objective of this study was to correlate the ultrasonic energy delivered to the sample (J/mL with the residual enzymatic activity and explain the possible mechanisms which results in the enzymatic activation/in activation complex behavior. The activity of POD in coconut water was evaluated as a model. The enzymatic activity initially increased, followed by reduction with a trend to enzyme inactivation. This complex behavior is directly related to the applied ultr asonic energy and their direct mechanical effects on the product, as well as the effect in the enzymatic infinite intermediate states and its structural conformation changes. The obtained results are useful for both academic and industrial perspectives.

  2. The ultrasound technology for modifying enzyme activity

    Directory of Open Access Journals (Sweden)

    Meliza Lindsay

    2016-06-01

    Full Text Available Enzymes are protein complexes compounds widely studied and used due to their ability to catalyze reactions. The food processing mainly aims the inactivation of enzymes due to various undesirable effects. However, there are many processes that can be optimized by its catalytic activity. In this context, different technologies have been applied both to inactivate or to improve the enzymes efficiency. The Ultrasound technology emerges as an alternative mainly applied to achieve the enzyme inactivation. On the contrary, very few investigations show the ability of this technology under certain conditions to achieve the opposite effect (i.e. increase the catalytic activity of enzymes. The objective of this study was to correlate the ultrasonic energy delivered to the sample (J/mL with the residual enzymatic activity and explain the possible mechanisms which results in the enzymatic activation/inactivation complex behavior. The activity of POD in coconut water was evaluated as a model. The enzymatic activity initially increased, followed by reduction with a trend to enzyme inactivation. This complex behavior is directly related to the applied ultrasonic energy and their direct mechanical effects on the product, as well as the effect in the enzymatic infinite intermediate states and its structural conformation changes. The obtained results are useful for both academic and industrial perspectives.

  3. Directed evolution of enzymes using microfluidic chips

    Science.gov (United States)

    Pilát, Zdeněk.; Ježek, Jan; Šmatlo, Filip; Kaůka, Jan; Zemánek, Pavel

    2016-12-01

    Enzymes are highly versatile and ubiquitous biological catalysts. They can greatly accelerate large variety of reactions, while ensuring appropriate catalytic activity and high selectivity. These properties make enzymes attractive biocatalysts for a wide range of industrial and biomedical applications. Over the last two decades, directed evolution of enzymes has transformed the field of protein engineering. We have devised microfluidic systems for directed evolution of haloalkane dehalogenases in emulsion droplets. In such a device, individual bacterial cells producing mutated variants of the same enzyme are encapsulated in microdroplets and supplied with a substrate. The conversion of a substrate by the enzyme produced by a single bacterium changes the pH in the droplet which is signalized by pH dependent fluorescence probe. The droplets with the highest enzymatic activity can be separated directly on the chip by dielectrophoresis and the resultant cell lineage can be used for enzyme production or for further rounds of directed evolution. This platform is applicable for fast screening of large libraries in directed evolution experiments requiring mutagenesis at multiple sites of a protein structure.

  4. Lysosomal enzyme activation in irradiated mammary tumors

    International Nuclear Information System (INIS)

    Clarke, C.; Wills, E.D.

    1976-01-01

    Lysosomal enzyme activity of C3H mouse mammary tumors was measured quantitatively by a histochemical method. Following whole-body doses of 3600 rad or less no changes were observed in the lysosomal enzyme activity for 12 hr after the irradiation, but very large increases in acid phosphatase and β-naphthylamidase activity were, however, observed 24 hr after irradiation. Significant increases in enzyme activity were detected 72 hr after a dose of 300 rad and the increases of enzyme activity were dose dependent over the range 300 to 900 rad. Testosterone (80 mg/kg) injected into mice 2 hr before irradiation (850 rad) caused a significant increase of lysosomal enzyme activity over and above that of the same dose of irradiation alone. If the tumor-bearing mice were given 95 percent oxygen/5 percent carbon dioxide to breathe for 8 min before irradiation the effect of 850 rad on lysosomal acid phosphatase was increased to 160 percent/that of the irradiation given alone. Activitation of lysosomal enzymes in mammary tumors is an important primary or secondary consequence of radiation

  5. Enzymes for Enhanced Oil Recovery (EOR)

    Energy Technology Data Exchange (ETDEWEB)

    Nasiri, Hamidreza

    2011-04-15

    Primary oil recovery by reservoir pressure depletion and secondary oil recovery by waterflooding usually result in poor displacement efficiency. As a consequence there is always some trapped oil remaining in oil reservoirs. Oil entrapment is a result of complex interactions between viscous, gravity and capillary forces. Improving recovery from hydrocarbon fields typically involves altering the relative importance of the viscous and capillary forces. The potential of many EOR methods depends on their influence on fluid/rock interactions related to wettability and fluid/fluid interactions reflected in IFT. If the method has the potential to change the interactions favorably, it may be considered for further investigation, i.e. core flooding experiment, pilot and reservoir implementation. Enzyme-proteins can be introduced as an enhanced oil recovery method to improve waterflood performance by affecting interactions at the oil-water-rock interfaces. An important part of this thesis was to investigate how selected enzymes may influence wettability and capillary forces in a crude oil-brine-rock system, and thus possibly contribute to enhanced oil recovery. To investigate further by which mechanisms selected enzyme-proteins may contribute to enhance oil recovery, groups of enzymes with different properties and catalytic functions, known to be interfacially active, were chosen to cover a wide range of possible effects. These groups include (1) Greenzyme (GZ) which is a commercial EOR enzyme and consists of enzymes and stabilizers (surfactants), (2) The Zonase group consists of two types of pure enzyme, Zonase1 and Zonase2 which are protease enzymes and whose catalytic functions are to hydrolyze (breakdown) peptide bonds, (3) The Novozyme (NZ) group consists of three types of pure enzyme, NZ2, NZ3 and NZ6 which are esterase enzymes and whose catalytic functions are to hydrolyze ester bonds, and (4) Alpha-Lactalbumin ( -La) which is an important whey protein. The effect of

  6. Computational Biochemistry-Enzyme Mechanisms Explored.

    Science.gov (United States)

    Culka, Martin; Gisdon, Florian J; Ullmann, G Matthias

    2017-01-01

    Understanding enzyme mechanisms is a major task to achieve in order to comprehend how living cells work. Recent advances in biomolecular research provide huge amount of data on enzyme kinetics and structure. The analysis of diverse experimental results and their combination into an overall picture is, however, often challenging. Microscopic details of the enzymatic processes are often anticipated based on several hints from macroscopic experimental data. Computational biochemistry aims at creation of a computational model of an enzyme in order to explain microscopic details of the catalytic process and reproduce or predict macroscopic experimental findings. Results of such computations are in part complementary to experimental data and provide an explanation of a biochemical process at the microscopic level. In order to evaluate the mechanism of an enzyme, a structural model is constructed which can be analyzed by several theoretical approaches. Several simulation methods can and should be combined to get a reliable picture of the process of interest. Furthermore, abstract models of biological systems can be constructed combining computational and experimental data. In this review, we discuss structural computational models of enzymatic systems. We first discuss various models to simulate enzyme catalysis. Furthermore, we review various approaches how to characterize the enzyme mechanism both qualitatively and quantitatively using different modeling approaches. © 2017 Elsevier Inc. All rights reserved.

  7. Activity assessment of microbial fibrinolytic enzymes.

    Science.gov (United States)

    Kotb, Essam

    2013-08-01

    Conversion of fibrinogen to fibrin inside blood vessels results in thrombosis, leading to myocardial infarction and other cardiovascular diseases. In general, there are four therapy options: surgical operation, intake of antiplatelets, anticoagulants, or fibrinolytic enzymes. Microbial fibrinolytic enzymes have attracted much more attention than typical thrombolytic agents because of the expensive prices and the side effects of the latter. The fibrinolytic enzymes were successively discovered from different microorganisms, the most important among which is the genus Bacillus. Microbial fibrinolytic enzymes, especially those from food-grade microorganisms, have the potential to be developed as functional food additives and drugs to prevent or cure thrombosis and other related diseases. There are several assay methods for these enzymes; this may due to the insolubility of substrate, fibrin. Existing assay methods can be divided into three major groups. The first group consists of assay of fibrinolytic activity with natural proteins as substrates, e.g., fibrin plate methods. The second and third groups of assays are suitable for kinetic studies and are based on the determination of hydrolysis of synthetic peptide esters. This review will deal primarily with the microorganisms that have been reported in literature to produce fibrinolytic enzymes and the first review discussing the methods used to assay the fibrinolytic activity.

  8. Enzyme-MOF (metal-organic framework) composites.

    Science.gov (United States)

    Lian, Xizhen; Fang, Yu; Joseph, Elizabeth; Wang, Qi; Li, Jialuo; Banerjee, Sayan; Lollar, Christina; Wang, Xuan; Zhou, Hong-Cai

    2017-06-06

    The ex vivo application of enzymes in various processes, especially via enzyme immobilization techniques, has been extensively studied in recent years in order to enhance the recyclability of enzymes, to minimize enzyme contamination in the product, and to explore novel horizons for enzymes in biomedical applications. Possessing remarkable amenability in structural design of the frameworks as well as almost unparalelled surface tunability, Metal-Organic Frameworks (MOFs) have been gaining popularity as candidates for enzyme immobilization platforms. Many MOF-enzyme composites have achieved unprecedented results, far outperforming free enzymes in many aspects. This review summarizes recent developments of MOF-enzyme composites with special emphasis on preparative techniques and the synergistic effects of enzymes and MOFs. The applications of MOF-enzyme composites, primarily in transferation, catalysis and sensing, are presented as well. The enhancement of enzymatic activity of the composites over free enzymes in biologically incompatible conditions is emphasized in many cases.

  9. Kinetics of enzyme action: essential principles for drug hunters

    National Research Council Canada - National Science Library

    Stein, Ross L

    2011-01-01

    ... field. Beginning with the most basic principles pertaining to simple, one-substrate enzyme reactions and their inhibitors, and progressing to a thorough treatment of two-substrate enzymes, Kinetics of Enzyme Action...

  10. One last boom : Alberta's rapidly expanding oil mines may be the largest and messiest industrial projects in Canadian history

    International Nuclear Information System (INIS)

    Laird, G.

    2001-01-01

    The bitumen deposits of Alberta, 2.5 trillion barrels of oil, of which 300 billion are considered recoverable, represent the greatest single petroleum resources of the world, based on surface and subsurface calculations. Four deposits, covering an area the size of New Brunswick, are located in the area stretching from Cold Lake to Lloydminster (east of Edmonton), the upper reaches of the Athabasca River east to the Peace River. The largest by far is the Athabasca deposit in the vicinity of Fort McMurray, spread over 4.3 million hectares. The deposit is at the centre of the biggest industrial expansion witnessed by the province. Since 1996, 38 billion dollars worth of new projects have been announced. It is estimated that by 2025, the bulk of the national oil production will originate from open-pit mines and underground wells around Fort McMurray. This oil boom has economic benefits for the population, from welders to real estate agents to stakeholders. The environmental effects are not as beneficial. Huge strip mines are being carved next to the Athabasca River, with great amounts of greenhouse gases emissions. The Suncor and Syncrude oil-sands plants combined represent the fourth largest carbon dioxide emission source in Canada. The development of these projects dramatically affects global warming. The nitrogen and sulphur emissions could also acidify lakes and soil in the region. The Suncor mine resulted from the first boom to hit Fort McMurray in 1964. The Syncrude mine is the result of the second boom which took place in 1973. In 1996, Suncor installed a sulphur scrubber system that removes 95 per cent of sulphur dioxide from the electricity and steam-generation plant. Suncor also invested in various projects, such as wind-power, rainforest cultivation and biomass generation. The volume of pollution increases as the operations expand, even if operations are cleaner. If no new gains in pollution control are achieved, it is expected that by 2015, the total

  11. City-ecological perspectives of the development of high urbanized multifunctional centers of the largest Russian cities

    Directory of Open Access Journals (Sweden)

    Kolesnikov Sergey Anatol’evich

    2015-01-01

    Full Text Available This article presents some results of the author’s dissertation research dedicated to formation of an architectural typology of high urbanized multifunctional units of urban structure of the largest cities (further HUMUUS as centers of social activity, which include buildings, constructions, transportation equipment and open spaces, where human flows transpose, start and end with the purpose of bringing into this space a concentrated maximum of goods, services and information with minimum time expenditures. This article draws attention to the development analysis of the structure-forming functions of HUMUUS and their town planning and environmental impact on the surrounding area. The study of planning structures of the largest Russian cities (Samara, Kazan, Nizhny Novgorod made it possible to identify a number of main objects, in which structure-forming functions of HUMUUS are materialized: railroad complex (historically formed, developed, dominated, system-wide road junction, transport interchange hub (providing intraurban messages, public office and business centers, leisure and entertainment centers, shopping centers. Basing on researches of Russian and foreign experience, it is possible to predict with full confidence the following trends and streams of environmental and urban development of HUMUUS in the near-term perspective: Strengthening of the environmental and urban frame by network evolution of HUMUUS; Inclusion of green areas of HUMUUS in the system of citywide green areas; Increment of the interest of the investors to the public road junction for the purpose of reorganization of them to full HUMUUS with all characteristics of high-urbanized and environmental and urban reorganization (separation of traffic and pedestrian flows, maximum capacity, multiple-level system, multifunctional, increase in landscaped green space, reconstruction of engineering systems and communications, the use of modern ecological building designs and

  12. Continuous enzyme reactions with immobilized enzyme tubes prepared by radiation cast-polymerization

    International Nuclear Information System (INIS)

    Kumakura, Minoru; Kaetsu, Isao

    1986-01-01

    Immobilized glucose oxidase tubes were prepared by radiation cast-polymerization of 2-hydroxyethyl methacrylate and tetraethyleneglycol diacrylate monomer at low temperatures. The immobilized enzyme tubes which were spirally set in a water bath were used as reactor, in which the enzyme activity varied with tube size and flow rate of the substrate. The conversion yield of the substrate in continuous enzyme reaction was about 80%. (author)

  13. An estimation of the capacity to produce hydrogen by wasted hydroelectric energy for the three largest Brazilian hydroelectric

    Energy Technology Data Exchange (ETDEWEB)

    Padilha, Janine C.; Trindade, Leticia G. da; Souza, Roberto F. de [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Inst. of Chemistry], Email: janine@iq.ufrgs.br; Miguel, Marcelo [Itaipu Binacional, Foz do Iguacu, PR (Brazil)

    2010-07-01

    The use of water wasted in hydroelectric plants as normalization dam excess, which constitute a hydrodynamic potential useful to generate electric energy which can be subsequently used to produce hydrogen and its subsequent consumption in fuel cells has been considered as an alternative for hydraulic energy-rich countries like Brazil. The case is examined in which all the water wasted in the hydroelectric plants, spilled by dam gates to maintain acceptable water levels, from the 3 largest Brazilian hydroelectric plants was used to produce hydrogen. During the year of 2008, the electric energy produced from this utilization would have been equivalent to 52.8 TWh, an amount that corresponds to an increase of ca. 15% of the total electric energy produced in the country. Furthermore, if this amount of hydrogen was used in the replacement of internal combustion vehicles by fuel cells, this would have prevented the production of 2.26 x 10{sup 7} ton of Co{sub 2} per year. This plan would also significantly decrease production and release of greenhouse gases. (author)

  14. Community structure and decadal changes in macrozoobenthic assemblages in Lake Poyang, the largest freshwater lake in China

    Directory of Open Access Journals (Sweden)

    Cai Y. J.

    2014-01-01

    Full Text Available Lake Poyang is the largest freshwater lake in China and contains unique and diverse biota within the Yangtze floodplain ecosystem. However, knowledge of its macrozoobenthic assemblages remains inadequate. To characterize the current community structure of these assemblages and to portray their decadal changes, quarterly investigations were conducted at 15 sites from February to November 2012. A total of 42 taxa were recorded, and Corbicula fluminea, Limnoperna fortunei, Gammaridae sp., Nephtys polybranchia, Polypedilum scalaenum and Branchiura sowerbyi were found to dominate the community in terms of abundance. The bivalves Corbicula fluminea, Lamprotula rochechouarti, Arconaia lanceolata and Lamprotula caveata dominated the community in biomass due to their large body size. The mean abundance of the total macrozoobenthos varied from 48 to 920 ind·m-2, the mean biomass ranged from 28 to 428 g·m-2. The substrate type affected strongly the abundance, biomass, and diversity of the macrozoobenthos, with muddy sand substrates showing the highest values. Compared with historical data, remarkable changes were observed in the abundance of macrozoobenthos and the identity of the dominant species. The mean total abundance decreased from 724 ind·m-2 in 1992 to 228 ind·m-2 in 2012. The dominant species have shifted dramatically. Large unionids were dominant before 1998, whereas pollution-tolerant species (e.g., Branchiura sowerbyi increased in dominance after 2008. Our findings should have implications for the conservation of the benthic biodiversity of this large Yangtze-connected lake.

  15. Properties of the probability distribution associated with the largest event in an earthquake cluster and their implications to foreshocks

    International Nuclear Information System (INIS)

    Zhuang Jiancang; Ogata, Yosihiko

    2006-01-01

    The space-time epidemic-type aftershock sequence model is a stochastic branching process in which earthquake activity is classified into background and clustering components and each earthquake triggers other earthquakes independently according to certain rules. This paper gives the probability distributions associated with the largest event in a cluster and their properties for all three cases when the process is subcritical, critical, and supercritical. One of the direct uses of these probability distributions is to evaluate the probability of an earthquake to be a foreshock, and magnitude distributions of foreshocks and nonforeshock earthquakes. To verify these theoretical results, the Japan Meteorological Agency earthquake catalog is analyzed. The proportion of events that have 1 or more larger descendants in total events is found to be as high as about 15%. When the differences between background events and triggered event in the behavior of triggering children are considered, a background event has a probability about 8% to be a foreshock. This probability decreases when the magnitude of the background event increases. These results, obtained from a complicated clustering model, where the characteristics of background events and triggered events are different, are consistent with the results obtained in [Ogata et al., Geophys. J. Int. 127, 17 (1996)] by using the conventional single-linked cluster declustering method

  16. Properties of the probability distribution associated with the largest event in an earthquake cluster and their implications to foreshocks.

    Science.gov (United States)

    Zhuang, Jiancang; Ogata, Yosihiko

    2006-04-01

    The space-time epidemic-type aftershock sequence model is a stochastic branching process in which earthquake activity is classified into background and clustering components and each earthquake triggers other earthquakes independently according to certain rules. This paper gives the probability distributions associated with the largest event in a cluster and their properties for all three cases when the process is subcritical, critical, and supercritical. One of the direct uses of these probability distributions is to evaluate the probability of an earthquake to be a foreshock, and magnitude distributions of foreshocks and nonforeshock earthquakes. To verify these theoretical results, the Japan Meteorological Agency earthquake catalog is analyzed. The proportion of events that have 1 or more larger descendants in total events is found to be as high as about 15%. When the differences between background events and triggered event in the behavior of triggering children are considered, a background event has a probability about 8% to be a foreshock. This probability decreases when the magnitude of the background event increases. These results, obtained from a complicated clustering model, where the characteristics of background events and triggered events are different, are consistent with the results obtained in [Ogata, Geophys. J. Int. 127, 17 (1996)] by using the conventional single-linked cluster declustering method.

  17. Customized overhead cranes for installation of India's largest 3.6m optical telescope at Devasthal, Nainital, India

    Science.gov (United States)

    Bangia, Tarun; Yadava, Shobhit; Kumar, Brijesh; Ghanti, A. S.; Hardikar, P. M.

    2016-07-01

    India's largest 3.6 m aperture optical telescope facility has been recently established at Devasthal site by Aryabhatta Research Institute of Observation Sciences (ARIES), an autonomous Institute under Department of Science and Technology, Government of India. The telescope is equipped with active optics and it is designed to be used for seeinglimited observations at visible and near-infrared wavelengths. A steel building with rotating cylindrical steel Dome was erected to house 3.6m telescope and its accessories at hilltop of Devasthal site. Customized cranes were essentially required inside the building as there were space constraints around the telescope building for operating big external heavy duty cranes from outside, transportation constraints in route for bringing heavy weight cranes, altitude of observatory, and sharp bends etc. to site. To meet the challenge of telescope installation from inside the telescope building by lifting components through its hatch, two Single Girder cranes and two Under Slung cranes of 10 MT capacity each were specifically designed and developed. All the four overhead cranes were custom built to achieve the goal of handling telescope mirror and its various components during installation and assembly. Overhead cranes were installed in limited available space inside the building and tested as per IS 3177. Cranes were equipped with many features like VVVFD compatibility, provision for tandem operation, digital load display, anti-collision mechanism, electrical interlocks, radio remote, low hook height and compact carriage etc. for telescope integration at site.

  18. Largest case series of Latin American eyelid tumors over 13-Years from a single center in Sao Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Jéssica Carolinne Damasceno

    Full Text Available ABSTRACT Purpose: Malignant lesions of the eyelid are the most common eye cancers. Although rarely lethal, late diagnosis can lead to serious visual morbidity. Definitive diagnosis of neoplastic lesions is pathological. Indications and types of eyelid lesions in a single high-volume ophthalmic reference center in Sao Paulo, Brazil, were analyzed. Methods: The surgical pathological reports of patients who underwent eye removal procedures between January 2000 and December 2012 were retrieved from the electronic database of the Ophthalmology Department and retrospectively reviewed. Data regarding the final anatomopathological diagnosis, sex, and age were analyzed via the χ2 test with Yates' correction. Results: Of the 1,113 eyelid tumors resected over the 13-year study period, 324 (29% lesions were malignant. The most prevalent lesions were basal cell, squamous cell, and sebaceous gland carcinomas. The median ages of patients (females, n=165, 51%; males, n=159, 49% with a diagnosis of basal cell, squamous cell, and sebaceous gland carcinomas were 65, 75, and 70 years, respectively. Conclusion: This is the largest retrospective cohort analysis of eyelid tumors in a Latin American population. These findings are in agreement with those from large centers in other countries and regions.

  19. Significant human impact on the flux and δ(34)S of sulfate from the largest river in North America.

    Science.gov (United States)

    Killingsworth, Bryan A; Bao, Huiming

    2015-04-21

    Riverine dissolved sulfate (SO4(2-)) flux and sulfur stable isotope composition (δ(34)S) yield information on the sources and processes affecting sulfur cycling on different spatial and temporal scales. However, because pristine preindustrial natural baselines of riverine SO4(2-) flux and δ(34)S cannot be directly measured, anthropogenic impact remains largely unconstrained. Here we quantify natural and anthropogenic SO4(2-) flux and δ(34)S for North America's largest river, the Mississippi, by means of an exhaustive source compilation and multiyear monitoring. Our data and analysis show that, since before industrialization to the present, Mississippi River SO4(2-) has increased in flux from 7.0 to 27.8 Tg SO4(2-) yr(-1), and in mean δ(34)S from -5.0‰, within 95% confidence limits of -14.8‰ to 4.1‰ (assuming normal distribution for mixing model input parameters), to -2.7 ± 1.6‰, reflecting an impressive footprint of bedrocks particular to this river basin and human activities. Our first-order modern Mississippi River sulfate partition is 25 ± 6% natural and 75% ± 6% anthropogenic sources. Furthermore, anthropogenic coal usage is implicated as the dominant source of modern Mississippi River sulfate, with an estimated 47 ± 5% and 13% of total Mississippi River sulfate due to coal mining and burning, respectively.

  20. Atmospheric thorium pollution and inhalation exposure in the largest rare earth mining and smelting area in China.

    Science.gov (United States)

    Wang, Lingqing; Zhong, Buqing; Liang, Tao; Xing, Baoshan; Zhu, Yifang

    2016-12-01

    Exposure to radionuclide thorium (Th) has generated widespread public concerns, mainly because of its radiological effects on human health. Activity levels of airborne 232 Th in total suspended particulate (TSP) were measured in the vicinity of the largest rare earth mine in China in August 2012 and March 2013. The mean activity concentrations of 232 Th in TSP ranged from 820μBqm -3 in a mining area in August 2012 to 39,720μBqm -3 in a smelting area in March 2013, much higher than the world reference of 0.5μBqm -3 . Multistatistical analysis and Kohonen's self-organizing maps suggested that 232 Th in TSP was mainly derived from rare earth mining and smelting practices. In addition, personal inhalation exposures to 232 Th associated with respirable particulate (PM 10 ) were also measured among local dwellers via personal monitoring. The mean dose values for different age groups in the smelting and mining areas ranged from 97.86 to 417μSvyear - 1 and from 101.03 to 430.83μSvyear -1 , respectively. These results indicate that people living in the study areas are exposed to high levels of widespread 232 Th. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Injury Rates on New and Old Technology Oil and Gas Rigs Operated by the Largest United States Onshore Drilling Contractor

    Science.gov (United States)

    Blackley, David J.; Retzer, Kyla D.; Hubler, Warren G.; Hill, Ryan D.; Laney, A. Scott

    2015-01-01

    Background Occupational fatality rates among oil and gas extraction industry and specifically among drilling contractor workers are high compared to the U.S. all-industry average. There is scant literature focused on non-fatal injuries among drilling contractors, some of which have introduced engineering controls to improve rig efficiency and reduce injury risk. Methods We compared injury rates on new and old technology rigs operated by the largest U.S. drilling contractor during 2003–2012, stratifying by job type and grouping outcomes by injury severity and body part affected. Results Six hundred seventy-one injuries were recorded over 77.4 million person-hours. The rate on new rigs was 66% of that on old rigs. Roughnecks had lower injury rates on new rigs, largely through reduced limb injury rates. New rigs had lower rates in each non-fatal injury severity category. Conclusions For this company, new technology rigs appear to provide a safer environment for roughnecks. Future studies could include data from additional companies. PMID:25164118

  2. BEHAVIOR OF THE TEN LARGEST BRAZILIAN BANKS DURING THE SUBPRIME CRISIS: AN ANALYSIS BASED ON FINANCIAL INDICATORS

    Directory of Open Access Journals (Sweden)

    Rosane Maria Pio da Silva

    2012-06-01

    Full Text Available The aim of this paper is to demonstrate the behavior of the ten largest Brazilian banks between June 2008 and September 2009, based on the analysis of financial indicators. Therefore, 16 three-monthly indices were calculated, extracted from financial statement information, which characterizes a documentary research. The indices were separated in five categories: liquidity, capital, profitability, income and market. The obtained results appointed that most financial institutions in the sample were able to manage their resources so as to gain conditions to maintain credit initially. Then, as from the first term of 2009, driven by public banks, they increased their credit operations. In addition, most banks revealed an anti-cyclical trend to encourage productive activities, preferably activities with higher liquidity levels, to the detriment of profitability, which reveals a more conservative attitude. Finally, it was verified that government initiatives, the Brazilian economic balance and the resources the banks offered helped to produce an environment to reactivate business activities during the most acute period of the subprime crisis.

  3. A look at one of the world`s largest apron feeder drives - Alberta Oil Sands Project

    Energy Technology Data Exchange (ETDEWEB)

    Persson, O. [Hagglunds Drives Canada Inc., Vancouver, BC (Canada)

    1999-10-01

    Various types of equipment to transport tar sands to processing plants are discussed, with special attention to the advantages of hydraulic direct drives over conventional electro-mechanical drives. A hydraulic direct drive such as the Hagglund Drive has exceptional starting torque capacity due to the high torque capability of the hydraulic motor. As such, it can be particularly useful in applications where shock loads occur with some frequency, or where many starts and stops are needed. Application of the Hagglund drive to power one of the world`s largest apron feeders in the Alberta Oil Sands is described as an illustration of the exceptional reliability, productivity and performance of this equipment. It has about one five-hundredth of the inertia of an equivalent high speed drive with gear reducer, a feature which is particularly significant in the case of feeders which are known to suffer much downtime due to chain related problems. These types of drives have also been used to great advantage in the process industries like pulp and paper, chemical, rubber and plastics, recycling and steel. 1 tab., 1 fig.

  4. A look at one of the world's largest apron feeder drives - Alberta Oil Sands Project

    Energy Technology Data Exchange (ETDEWEB)

    Persson, O. (Hagglunds Drives Canada Inc., Vancouver, BC (Canada))

    1999-01-01

    Various types of equipment to transport tar sands to processing plants are discussed, with special attention to the advantages of hydraulic direct drives over conventional electro-mechanical drives. A hydraulic direct drive such as the Hagglund Drive has exceptional starting torque capacity due to the high torque capability of the hydraulic motor. As such, it can be particularly useful in applications where shock loads occur with some frequency, or where many starts and stops are needed. Application of the Hagglund drive to power one of the world's largest apron feeders in the Alberta Oil Sands is described as an illustration of the exceptional reliability, productivity and performance of this equipment. It has about one five-hundredth of the inertia of an equivalent high speed drive with gear reducer, a feature which is particularly significant in the case of feeders which are known to suffer much downtime due to chain related problems. These types of drives have also been used to great advantage in the process industries like pulp and paper, chemical, rubber and plastics, recycling and steel. 1 tab., 1 fig.

  5. Swimming strategy and body plan of the world’s largest fish: implications for foraging efficiency and thermoregulation

    Directory of Open Access Journals (Sweden)

    Mark eMeekan

    2015-09-01

    Full Text Available The largest animals in the oceans eat prey that are orders of magnitude smaller than themselves, implying strong selection for cost-effective foraging to meet their energy demands. Whale sharks (Rhincodon typus may be especially challenged by warm seas that elevate their metabolism and contain sparse prey resources. Using a combination of biologging and satellite tagging, we show that whale sharks use four strategies to save energy and improve foraging efficiency: 1 fixed, low power swimming, 2 constant low speed swimming, 3 gliding and 4 asymmetrical diving. These strategies increase foraging efficiency by 22 – 32% relative to swimming horizontally and resolve the energy-budget paradox of whale sharks. However, sharks in the open ocean must access food resources that reside in relatively cold waters (up to 20oC cooler than the surface at depths of 250-500 m during the daytime, where long, slow gliding descents, continuous ram ventilation of the gills and filter-feeding could rapidly cool the circulating blood and body tissues. We suggest that whale sharks may overcome this problem through their large size and a specialized body plan that isolates highly vascularized red muscle on the dorsal surface, allowing heat to be retained near the centre of the body within a massive core of white muscle. This could allow a warm-adapted species to maintain enhanced function of organs and sensory systems while exploiting food resources in deep, cool water.

  6. Largest global shark biomass found in the northern Galápagos Islands of Darwin and Wolf

    Directory of Open Access Journals (Sweden)

    Pelayo Salinas de León

    2016-05-01

    Full Text Available Overfishing has dramatically depleted sharks and other large predatory fishes worldwide except for a few remote and/or well-protected areas. The islands of Darwin and Wolf in the far north of the Galapagos Marine Reserve (GMR are known for their large shark abundance, making them a global scuba diving and conservation hotspot. Here we report quantitative estimates of fish abundance at Darwin and Wolf over two consecutive years using stereo-video surveys, which reveal the largest reef fish biomass ever reported (17.5 t ${\\mathrm{ha}}^{-1}$ ha − 1 on average, consisting largely of sharks. Despite this, the abundance of reef fishes around the GMR, such as groupers, has been severely reduced because of unsustainable fishing practices. Although Darwin and Wolf are within the GMR, they were not fully protected from fishing until March 2016. Given the ecological value and the economic importance of Darwin and Wolf for the dive tourism industry, the current protection should ensure the long-term conservation of this hotspot of unique global value.

  7. Assessment of microcystins in lake water and fish (Mugilidae, Liza sp.) in the largest Spanish coastal lake.

    Science.gov (United States)

    Romo, Susana; Fernández, Francisca; Ouahid, Youness; Barón-Sola, Ángel

    2012-01-01

    Cyanobacteria dominance and cyanotoxin production can become major threats to humans and aquatic life, especially in warm shallow lakes, which are often dominated by cyanobacteria. This study investigates the occurrence and distribution of microcystins (MCYST) in water, cell-bound and in the tissues of the commercial mugilid Liza sp. in the largest, coastal, Spanish Mediterranean lake (Albufera of Valencia). This is the first report concerning microcystin accumulation in tissues of mugilid fish species. Considerable amounts of microcystins were found in the water and seston, which correlated with development of Microcystis aeruginosa populations in the lake. The MCYST concentrations found in Lake Albufera (mean 1.7 and 17 μg/L and maximum 16 and 120 μg/L in water and seston, respectively) exceeded by one to two orders of magnitude the guideline levels proposed by the World Health Organization and were higher than that reported in other lakes of the Mediterranean zone. The presence of MCYST was found in all the fishes studied and accumulated differently among tissues of the commercial species Liza sp. Toxin accumulation in fish tissues showed that although the target organ for MCYST was the liver, high concentrations of microcystins were also found in other analysed tissues (liver>intestine>gills>muscle). Human tolerable daily intake for microcystins is assessed relative to the WHO guidelines, and potential toxicological risks for humans, wildlife and related ecosystems of the lake are discussed.

  8. Transit profiles: The thirty largest agencies for the 1990 Section 15 report year. Rept. for Jan-Dec 90

    International Nuclear Information System (INIS)

    Futrell, M.; Black, T.N.

    1991-11-01

    The report summarizes the financial and operating data submitted to the Urban Mass Transportation Administration (UMTA) by the nation's public transit operators, pursuant to Section 15 of the Urban Mass Transportation (UMT) Act of 1964, as amended. These data represent a portion of the 1990 Annual Report and consist of transit profiles for the 30 largest agencies based on operating expenses for the 1990 report year. Each profile consists of data reporting general, summary, modal, performance and trend indicators about a particular transit system for the 1990 report year. The unaggregated data can be found in the 1990 Section 15 Annual Report Data Tables, for the 1990 Section 15 Report Year. Rather than requiring the user to assemble data from numerous tables, the Transit Profile provides the user with a comprehensive overview in graphic and summary format of an individual transit agency's financial and operating statistics for the 1990 Section 15 report year with summaries of key data items for prior years. All data in the report are for transit system fiscal years ending on or between January 1 and December 31, 1990

  9. Assimilation of remote sensing observations into a sediment transport model of China's largest freshwater lake: spatial and temporal effects.

    Science.gov (United States)

    Zhang, Peng; Chen, Xiaoling; Lu, Jianzhong; Zhang, Wei

    2015-12-01

    Numerical models are important tools that are used in studies of sediment dynamics in inland and coastal waters, and these models can now benefit from the use of integrated remote sensing observations. This study explores a scheme for assimilating remotely sensed suspended sediment (from charge-coupled device (CCD) images obtained from the Huanjing (HJ) satellite) into a two-dimensional sediment transport model of Poyang Lake, the largest freshwater lake in China. Optimal interpolation is used as the assimilation method, and model predictions are obtained by combining four remote sensing images. The parameters for optimal interpolation are determined through a series of assimilation experiments evaluating the sediment predictions based on field measurements. The model with assimilation of remotely sensed sediment reduces the root-mean-square error of the predicted sediment concentrations by 39.4% relative to the model without assimilation, demonstrating the effectiveness of the assimilation scheme. The spatial effect of assimilation is explored by comparing model predictions with remotely sensed sediment, revealing that the model with assimilation generates reasonable spatial distribution patterns of suspended sediment. The temporal effect of assimilation on the model's predictive capabilities varies spatially, with an average temporal effect of approximately 10.8 days. The current velocities which dominate the rate and direction of sediment transport most likely result in spatial differences in the temporal effect of assimilation on model predictions.

  10. Loss of largest and oldest individuals of the Montpellier snake correlates with recent warming in the southeastern Iberian Peninsula.

    Science.gov (United States)

    López-Calderón, Cosme; Feriche, Mónica; Alaminos, Esmeralda; Pleguezuelos, Juan M

    2017-12-01

    The effects of climate change on organisms are now being extensively studied in many different taxa. However, the variation in body size, usually shrinkage in response to increasing temperature, has received little attention regarding to reptiles. During past periods of global warming, many organisms shrank in size, and current evidence and experiments manipulating temperature have shown a biomass decrease in some organisms with increasing temperatures. Here we test whether the body size of the Montpellier snake Malpolon monspessulanus from the southeastern Iberian Peninsula is changing and correlated with the increasing temperature in this region during a 39-year period (1976-2014). We measured the snout-vent length (SVL) of vouchers in scientific collections to check for trends in adult body size at the population level in relation with temperature, while controlling for the age of the individuals (estimated by skeletochronology, n  =141). Given the great ontogenetic variation in body size of the study species, we categorized age in 3 classes: "young adults" (under 5 years old), "intermediate adults" (from 5 to 7 years old), and "old adults" (from 8 to 14 years old). By means of linear mixed models, we found a negative relationship between SVL of "old adults" and average annual temperature in the region during the lifetime of each individual. Our results indicate that largest and oldest individuals of the Montpellier Snake, that is, males because of strong sexual size dimorphism in this species, disappeared from the study population, and suggest that it occurred in response to rising environmental temperature.

  11. A case of multiple metastatic malignant melanoma with the largest lesion in the ileum and no skin lesion

    Directory of Open Access Journals (Sweden)

    Shuji Suzuki

    2012-12-01

    Full Text Available We report the case of a 72-year-old woman with malignant melanoma and multiple metastases; the largest tumor was in the ileum. The patient experienced general fatigue and bloody feces for 1 month before consulting a nearby clinic. Blood tests revealed anemia, and fecal occult blood was positive, but no abnormalities were detected using gastrointestinal endoscopy and colonoscopy or the skin of the entire body. Computed tomography images of the chest, abdomen, and pelvic region, and positron emission tomography–computed tomography images of the entire body revealed multiple nodules in the ileum, left mammary gland, left thyroid, right inguinal lymph node, and on the fascia of the right thoracic area and right buttocks. The tumor in the left mammary gland was excised and immunohistochemical analysis revealed that the excised tissue was positive for HMB45, melan-A, and MITF, but negative for S-100 protein. Diagnosed with melanoma with multiple metastases, the patient underwent four cycles of dacarbazine, nimustine hydrochloride, and vincristine (DAV plus interferon beta chemotherapy and one cycle of dacarbazine, nimustine hydrochloride, cisplatin, and tamoxifen (DAC-Tam chemotherapy. Two series of embolizations of the artery feeding the ileum tumors, as well as a series of plasma and red blood cell transfusions, were performed for ileum tumor hemorrhage. The patient was hospitalized eight times, for a total of 204 days during the 1-year survival period before her death from respiratory failure.

  12. Injury rates on new and old technology oil and gas rigs operated by the largest United States onshore drilling contractor.

    Science.gov (United States)

    Blackley, David J; Retzer, Kyla D; Hubler, Warren G; Hill, Ryan D; Laney, A Scott

    2014-10-01

    Occupational fatality rates among oil and gas extraction industry and specifically among drilling contractor workers are high compared to the U.S. all-industry average. There is scant literature focused on non-fatal injuries among drilling contractors, some of which have introduced engineering controls to improve rig efficiency and reduce injury risk. We compared injury rates on new and old technology rigs operated by the largest U.S. drilling contractor during 2003-2012, stratifying by job type and grouping outcomes by injury severity and body part affected. Six hundred seventy-one injuries were recorded over 77.4 million person-hours. The rate on new rigs was 66% of that on old rigs. Roughnecks had lower injury rates on new rigs, largely through reduced limb injury rates. New rigs had lower rates in each non-fatal injury severity category. For this company, new technology rigs appear to provide a safer environment for roughnecks. Future studies could include data from additional companies. © 2014 Wiley Periodicals, Inc.

  13. Setting-up a cost recovery system for the largest wastewater treatment plant in South-East Asia.

    Science.gov (United States)

    Lønholdt, J; Elberg Jørgensen, P; O'Hearn, D

    2005-01-01

    A tariff system has been set up for the largest wastewater treatment plant in South-East Asia, the Samut Prakarn Wastewater Treatment Plant south of Bangkok, which is currently under completion. Fully functional the plant will have a design capacity for 500,000 m3 per day and will service a combined residential and industrial area with approximately 600,000 residents and 2,300 factories. The tariff system, which includes a tariff model, is based on water consumption and BOD load. As background for setting the tariffs a comprehensive monitoring system including an industrial permitting system has been developed. The paper presents the background and rationale for setting up the system as well as the objective, scope and content of the tariff system and the industrial permit system. Further, the feasibility of introducing cost recovery systems, which is widely accepted in developing economies on the conceptual level and to some extent implemented at the legal and regulatory level, but has yet to be implemented at large, is discussed.

  14. Health Education Research and Practice Literature on Hispanic Health Issues: Have We Lost Sight of the Largest Minority Population?

    Science.gov (United States)

    Price, James H; Khubchandani, Jagdish

    2016-03-01

    Hispanics constitute the largest racial/ethnic minority population in the United States and are the fastest growing segment of the population. Knowledge about health needs and practices, effective health promotion programs, and health policy making for Hispanics has the potential to improve population health outcomes for this group. Continued research and practice literature will aid in accomplishing these objectives. However, little is known about the extent of health education-related literature available on Hispanic health issues. In this review, we analyzed research and practice publications in all health education-related journals to assess the volume of articles published on Hispanic health issues. We found that the portion of journal articles devoted to Hispanic health issues varied widely among the journals and that there was a very limited emphasis on Hispanic health-related issues. Journal editors and editorial board members may need to be more proactive in soliciting manuscripts on Hispanic health, and our practitioners may have to improve their professional skills and cultural competence in order to work with Hispanic populations to produce research and practice literature that is of adequate quantity and quality to help improve Hispanics' health. © 2016 Society for Public Health Education.

  15. HIV risks and HIV prevention among female sex workers in two largest urban settings in Croatia, 2008-2014.

    Science.gov (United States)

    Štulhofer, Aleksandar; Landripet, Ivan; Božić, Jasmina; Božičević, Ivana

    2015-01-01

    Harm reduction-based HIV prevention has been in place among female sex workers (FSWs) in Croatia for more than a decade. However, little is known about how well the existing programs meet the needs of FSWs in an environment where sex work remains criminalized and highly stigmatized. This study aims to assess changes in FSWs' vulnerability to HIV infection in the 2008-2014 period. Using convenience samples of FSWs in Croatia's two largest urban settings, behavioral data were collected in 2007-2008 and 2014. Outreach workers interviewed 154 FSWs in the first wave of the survey and 158 in the second. The period under observation was characterized by a stable prevalence of most HIV-relevant risk behaviors and experiences. Significant changes in client-based victimization and HIV knowledge were observed only among FSWs in the capital city. Substantial and mostly sustained levels of sexual and nonsexual victimization call for more research into the limits of the current behavior-based harm reduction approach to HIV prevention in the country.

  16. Dispersal syndromes in the largest protection area of the Atlantic Forest in the state of Paraiba, Brazil

    Directory of Open Access Journals (Sweden)

    Camila Ângelo Jerônimo Domingues

    2013-09-01

    Full Text Available The diaspore dispersal process is crucial for plant reproduction, since the diaspores must reach a suitable site to germinate. This paper aimed to study morphological aspects of diaspores and determine the dispersal syndromes of species occurring in the largest protection area of the Atlantic Forest in the state of Paraiba, Brazil, the Guaribas Biological Reserve. One conducted a monthly collection of fruits/seeds within the period from September 2007 to February 2009. All diaspores of the fruiting species were collected. After analyzing characteristics such as fruit and seed consistency, odor, color, size, and weight, one determined the dispersal syndrome of each species. One collected 3,080 diaspores belonging to 136 different species distributed into 27 families. Zoochory was the most abundant dispersal syndrome (58%, with 79 fruits adapted to it, followed by autochory (29%, and anemochory (13%. Throughout the study period, one found fruiting species, with a predominance of zoochoric fruits, a predictable fact in the Atlantic Forest, which provides fleshy fruits all the year round.

  17. Stabilization of enzymes in ionic liquids via modification of enzyme charge.

    Science.gov (United States)

    Nordwald, Erik M; Kaar, Joel L

    2013-09-01

    Due to the propensity of ionic liquids (ILs) to inactivate enzymes, the development of strategies to improve enzyme utility in these solvents is critical to fully exploit ILs for biocatalysis. We have developed a strategy to broadly improve enzyme utility in ILs based on elucidating the effect of charge modifications on the function of enzymes in IL environments. Results of stability studies in aqueous-IL mixtures indicated a clear connection between the ratio of enzyme-containing positive-to-negative sites and enzyme stability in ILs. Stability studies of the effect of [BMIM][Cl] and [EMIM][EtSO4 ] on chymotrypsin specifically found an optimum ratio of positively-charged amine-to-negatively-charged acid groups (0.39). At this ratio, the half-life of chymotrypsin was increased 1.6- and 4.3-fold relative to wild-type chymotrypsin in [BMIM][Cl] and [EMIM][EtSO4 ], respectively. The half-lives of lipase and papain were similarly increased as much as 4.0 and 2.4-fold, respectively, in [BMIM][Cl] by modifying the ratio of positive-to-negative sites of each enzyme. More generally, the results of stability studies found that modifications that reduce the ratio of enzyme-containing positive-to-negative sites improve enzyme stability in ILs. Understanding the impact of charge modification on enzyme stability in ILs may ultimately be exploited to rationally engineer enzymes for improved function in IL environments. Copyright © 2013 Wiley Periodicals, Inc.

  18. Comparison of Enzymes / Non-Enzymes Proteins Classification Models Based on 3D, Composition, Sequences and Topological Indices

    OpenAIRE

    Munteanu, Cristian Robert

    2014-01-01

    Comparison of Enzymes / Non-Enzymes Proteins Classification Models Based on 3D, Composition, Sequences and Topological Indices, German Conference on Bioinformatics (GCB), Potsdam, Germany (September, 2007)

  19. Enzymic conversion of starch to glucose

    Energy Technology Data Exchange (ETDEWEB)

    1964-08-19

    Corn is steeped in a SO/sub 2/ solution for 30 to 40 hours, coarsely ground, separated from the germ, and filtered. A 35% suspension of the germ-free corn, still containing fibers, hull, and gluten, is treated with Ca(OH)/sub 2/ to raise the pH to 6.5 to 7.0. A starch-liquifying enzyme is added and after a 2 hours treatment at 85/sup 0/ the liquefied starch is cooled to 60/sup 0/ and the pH is adjusted to 4.5 to 5.0 with H/sub 2/SO/sub 4/. A saccharifying enzyme is now added. After 40 to 81 hours, a raw glucose solution is obtained and is freed from fibers and gluten by filtration. The commercial starch-liquifying enzymes are designated HT-1000 and Neozyme 3 LC (liquid). The saccharifying enzymes are Diazyme or Diazyme L 30 (liquid). The solid enzymes are used at a level up to 0.1% by weight of the starch. Up to 100% conversion of starch into glucose is achieved.

  20. Thermophilic archaeal enzymes and applications in biocatalysis.

    Science.gov (United States)

    Littlechild, Jennifer A

    2011-01-01

    Thermophilic enzymes have advantages for their use in commercial applications and particularly for the production of chiral compounds to produce optically pure pharmaceuticals. They can be used as biocatalysts in the application of 'green chemistry'. The thermophilic archaea contain enzymes that have already been used in commercial applications such as the L-aminoacylase from Thermococcus litoralis for the resolution of amino acids and amino acid analogues. This enzyme differs from bacterial L-aminoacylases and has similarities to carboxypeptidases from other archaeal species. An amidase/γ-lactamase from Sulfolobus solfataricus has been used for the production of optically pure γ-lactam, the building block for antiviral carbocyclic nucleotides. This enzyme has similarities to the bacterial signature amidase family. An alcohol dehydrogenase from Aeropyrum pernix has been used for the production of optically pure alcohols and is related to the zinc-containing eukaryotic alcohol dehydrogenases. A transaminase and a dehalogenase from Sulfolobus species have also been studied. The archaeal transaminase is found in a pathway for serine synthesis which is found only in eukaryotes and not in bacteria. It can be used for the asymmetric synthesis of homochiral amines of high enantioselective purity. The L-2-haloacid dehalogenase has applications both in biocatalysis and in bioremediation. All of these enzymes have increased thermostability over their mesophilic counterparts.